DRAFT - Intent of Design Narrative 9-5-19.pdfCity of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Intent of Design Narrative
General (G-Sheets)
• The City of Edmonds has recently contracted with Ameresco and BHC to design
and construct a new solids -handling facility including a new dryer and a pyrolysis
process to produce biochar. Process calculations for the required sizing and
basis of design of major equipment are provided in the Engineering Report and
associated Appendices. The Basis of Design (BOD) Technical Memorandum
provides solids sizing criteria for the dryer and pyrolysis processes.
• The General Drawings include an overview of the project location, project
process flow diagram (PFD), drawing list, equipment list, piping schedule, and
valve list.
• The equipment list provides major equipment with associated equipment tags.
Equipment lists for individual equipment packages are be provided separately as
manufacturer packages. See G-4 for the PFD and G-6 and G-7 for the equipment
list, valve list, and piping schedule.
• Two surveys were performed by KPG — one of the WWTP parking lot and 2nd
Ave and a second on the west side of the Solids Processing Building. Surveys
are shown on G-5. Datum adjustment was defined as part of the KPG survey. All
as -built drawing elevations need to be adjusted down by 2.69 ft. The 60%
drawings account for this adjustment.
• Area classification sheets (G-8 through G-13) show the area classifications per
NFPA 820. Electrical equipment within these shown areas must comply with area
classification requirements. Under separate cover, the 60% submittal includes a
DRAFT — NFPA Compliance Report which summarizes the design area and
process hazards analysis performed for the 60% Design.
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Demolition (D-Sheets)
Demolition for the project will occur in three major areas: headworks building, solids
process building, and site demolition.
• Site Demolition (D-1, D-2, and D-3)
o Site demolition will include the removal of all asphalt paving within the
existing WWTP parking lot. Asphalt will be removed to facilitate utility
relocation, Pyrolysis Building construction, and to accommodate potential
regrading as required by stormwater design (see Civil). Site demolition
will also include the removal of the existing cast -in place wall connecting
the Headworks Building and Solids Process Building. Demolition of this
wall shall include its footings. Removal of existing concrete sidewalk
behind wall will also be required. Removal of the existing swing gate will
be required.
o Site demolition also include the removal and relocation of utilizes as
required by the design. Relocation of such utilities is shown on Civil
drawings.
o Site demolition must protect two 24-inch influent lines that must remain in
service at all times. Furthermore, existing buried fuel storage tank shall
remain in place and operational at all times during demolition and
construction activities. Protect existing concrete apron at entrance of
WWTP.
• Solids Process Building Demolition (D-4, D-5, and D-6)
o Demolition in the Solids Processing Building will include the removal of all
mechanical equipment and associated piping; supports; platforms;
electrical; controls; and associated structural, mechanical, electrical
appurtenances associated with the Incinerator and its subsystems shall be
removed in their entirety. All equipment pads shall be ground down flush
with floor slab elevations. All equipment mezzanines, access ladders, and
stairs shall be removed accordingly. The existing concrete cantilevered
walkway and the platform at the shop level and the platform's columns at
the center of the current incinerator room shall be demolished. The extent
of the walkway demolition will only be needed where the new platform will
be located per Structural drawings. This is being done to seismically
attach the new dryer platform to the existing concrete walls.
• Headworks Building Demolition (D-7 and D-8)
o Headworks Building demolition includes the removal of the existing
screenings conveyor, screenings grinder, and two screenings pumps.
Misc. pipe removal and pipe/wall penetrations will be required.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Process Mechanical (M-Sheets)
• Screenings
o Screenings at the Edmonds WWTP are currently collected from the screens
and conveyed to a JWC Muffin Monster grinder via an enclosed belt
conveyor. The ground screenings are discharged by gravity to the screenings
hopper below. Non potable water (NPW) is added to the hopper to wash the
screenings. The resulting slurry is pumped using two screenings pumps
through a 4-inch ductile iron pipe to a washer -compactor in the Screw Press
Room. Compacted screenings are discharged onto the existing conveyors
(CVR-601 and CVR-602) and combined with dewatered sludge from the
screw presses before being fed to the incinerator.
o With the upgrade to pyrolysis, Ecology will not permit screenings to be
reintroduced to the process once removed at the headworks. As a result, the
current screenings operations will need to be revised. This design proposes
several process upgrades. First, screenings will be discharged to a new
reversing shaftless screw conveyor designed and manufactured by Austin -
Mac Inc (CVR-101). The conveyor will be able to discharge either to an
owner -provided dumpster or to the new grinder. The new grinder, provided by
JWC (G-101), will discharge into the existing screenings hopper and will
replace the existing JWC grinder in kind. The existing WEMCO model C
pumps (SP-101, SP-102) are not capable of providing sufficient head to the
proposed system. They will be replaced entirely, as the cost to replace the
existing motors and worn volutes is on par with a complete replacement.
o New screenings pumps will be required as the discharge location for the
pumps will change given the replacement and relocation of the washer
compactor. The existing screenings washer/compactor will be demolished
and a new washer -compactor by Kusters Water (SC-101) will be located on
the existing equipment platform in the repurposed Ash Dewatering Room,
repurposed as the "Screenings Disposal Room." The revised location for the
washer compactor added additional head to the already worn screenings
pumps in the Headworks Building, triggering their replacement per the above.
The screenings will be pumped from the Headworks Building through the
existing buried 4-inch screenings piping to the Solids Process Building.
Where the pipe enters the Dewatering Room, it will tie into a new pipe that will
connect up to the new washer compactor in the Screening Disposal Room
through the existing opening above the existing Ash Thickener. new pipe will
be installed that continues straight at the wye which leads to the existing
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
washer -compactor. The compacted screenings will be discharged into an
owner -provided 15-CY dumpster below.
• Dewatered Sludge (DS) Pump and Hopper
o The DS hopper and pump system is an equipment package supplied by
Schwing Bioset. This equipment package includes:
■ DS Hopper
• The new DS hopper will be live -bottom with integral push
frame. The DS hopper will be a cylindrical tank with flat
bottom and equipped with level control, foul air connections,
manway.
• The DS hopper will not be equipped with weight cells and
will not have an integral access platform and handrails.
• The DS hopper hydraulic push frame will be controlled by
the HPU MCP.
■ DS Twin Screw Feeder (provided by Owner)
• The DS twin screw feeder will feed DS from the hopper to
the pump and will be controlled by the HPU MCP.
■ DS Pump (provided by Owner)
• The KSP 12 pump with single discharge and equipped with
flow measurement will pump DS up to the Dryer feed via a 6-
inch pipe.
• The Dryer feed pipe will be equipped a pressure release
valve, not shown.
• The Dryer feed pipe will be equipped with a blank 24-inch
spool to accommodate the future installation of a sludge
lubrication system, not provided under this contract.
■ DS Hydraulic Power Unit (provided by Owner)
• The HPU will control all elements associated with the DS
hopper, twin screw feeder, and pump.
• Dryer and Dryer Subsystems - See Centrisys Equipment Package Information
• Pyrolysis - See Centrisys Equipment Package Information
• Odor Control
o The project includes modifications to the existing odor control system at
the WWTP and the installation of a new dryer odor control system. The
intent of design for the two systems is described in the following sections.
Schematics of the two systems are shown in M-20 and M-21.
o Dryer Odor Control System
■ Dewatered sludge will be fed to the new dryer designed and
provided by Centrisys (DR-101) to dry dewatered sludge to 75%
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WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
solids. The dried sludge will then be conveyed to the new pyrolysis
building for conversion to biochar.
■ The dryer installed is expected to produce 11,000 scfm of foul air,
which will be treated by a new two -stage chemical scrubber
provided by BioAir (WS-701). The nearby Alderwood WWTP, which
has similar sludge characteristics, allowed BioAir to sample and
test foul air from their Kruger dryer to provide design guidance for
the installation at the Edmonds WWTP. The new chemical scrubber
is designed to treat 11,000 scfm of foul air using 0.59 gallons per
hour of 93% sulfuric acid in the first stage, and 0.58 gallons per
hour of 50% sodium hydroxide and 12.5 gallons per hour of 12.5%
sodium hypochlorite in the second stage. The system is expected
to remove >99% of NH3, >99% of HzS, and >90% of amines from
the foul air. The dryer odor control system will require the addition
of two new sodium hypochlorite storage tanks and chemical pumps,
new caustic chemical pumps, and a new sulfuric acid tank and
chemical pumps. These are described in detail below:
• Two new 2,000 gallons XLPE Assman (ICT2000) storage
tanks (T-703 and T-704) will be installed immediately to the
east of the existing screw presses in the Dewatering Room.
The two new tanks will be installed within a concrete berm
area for secondary containment. The new tanks can be filled
either by gravity from the existing hypochlorite tanks or filled
directly with a newly installed fill line. Two hypochlorite
delivery peristaltic pumps (CP-701 A/B) will be installed
within the bermed area on a 316 SS rack and will draw from
a shared line connecting the two hypochlorite tanks. for the
delivery of hypochlorite to the scrubber. 1-inch hypochlorite
caustic piping will be routed to the new odor control system
as shown on drawings
• A new 500-gallon double -walled sulfuric acid tank (T-702)
provided by Assmann (IMT-550) will provide storage for the
chemical for use in the odor scrubber in the SE corner of the
Dewatering Room. A new 2-inch fill line will be installed and
co -located with existing chemical feed lines in the polymer
feed room. The tank will sit upon a 4-inch slab and be
connected to the existing building drain system, with a 2-inch
vent to the roof of the building. A concrete berm will be
placed around the tank for secondary containment. On the
west side of the berm, two peristaltic pumps (CP-702 A/B)
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
provided by BioAir will deliver the chemical to the odor
scrubber.
• Two new caustic chemical pump CP-703 A/B will be installed
on a new 316 SS support platform within the existing bermed
area of the caustic storage tank. The chemical pumps feed
will be tied into the existing discharge manifold of the caustic
tank. 1-inch caustic piping will be routed to the new odor
control system as shown on drawings. No additional
modifications to the caustic tank will be required.
• All chemical supply pumps are included in the BioAir
equipment package as the qdos Peristaltic Metering by
Watson -Marlow.
• Chemical fill lines for the sulfuric acid and hypochlorite tanks
will have remove level indication and audio/visual alarms on
the exterior eastern wall of the Solids Process Building with
automated valve interlock to avoid overfilling of chemical
storage tanks. Details with this system are not provided in
the 60% Design drawings.
■ The new odor control system (WS-701) will be placed to the south
of the existing Vanaire odor control system (WS-601). It is placed to
ensure that maintenance access remains in the southwest corner of
the building, with sufficient clearances around the system for
maintenance. FRP ducting will be installed to connect the dryer
exhaust to the new scrubber. The dryer odor control system will be
equipped with a 60 HP fan on a VFD which will be used to draw air
off of the dryer to maintain a Centrisys-required 4-inches of water
column in the combined dryer exhaust ducting. This fan will be
controlled by a pressure instrument in the ducting, not shown. As
the dryer air will be high in humidity, 1-inch condensate drains will
be installed in the dryer exhaust ducting and horizontal sections will
be installed with a minimum 2% slope to ensure pooling of
condensate does not occur. BioAir is not providing a stack to the
unit, contractor shall provide 28-inch RFP stack as shown on
drawings.
• The BioAir equipment package includes an option to add a
granular activated carbon (GAC) unit to the system. This
would require the installation of the unit on a concrete pad
with architectural screen on the West exterior wall of the
Dryer Room. The GAC tower would require a 3-inch drain
back to the existing Dryer Room sump. The installation of
the GAC would eliminate the need for the 28-inch FRP stack
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
currently shown above the new dryer odor control system as
the GAC system would become the new emission point for
the whole system. The GAC option is not shown in the 60%
Design drawings at this time as the decision to include this
element to the project has not been made. The odor control
system presented in the 60% Design drawings has
equipment sized to accommodate this optional GAC system
(fan and VFD are sized for the added headloss).
o Existing Odor Control System
■ The existing single stage chemical scrubber (WS-601) and
associated foul air fans (FIC- 631 and FIC-632) will not be modified
for this project. However, multiple connections to the existing
system will be revised/added. The additions/revisions to the system
will still allow the total airflow to remain below the existing system's
20,000 scfm design flow; therefore, the system's design removal
efficiencies will not be affected by this design. The new/revised
connections are shown on M-20.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Dust Collection
o A dust collection unit by Donaldson Torit (DC-801) will be installed in
proximity of the Pyrolysis Building (not shown on 60% Drawings) to
remove any potentially hazardous dust that may be required per NFPA
requirements and guidelines (See DRAFT — NFPA Compliance Report).
standards. See Dust Collection equipment package for details. The dust
collection system will include a fan that will draw air from various locations
in the dry cake and biochar conveyance system. Treated, dust -free, foul
air will be discharged from the dust collection system into the WWTP odor
control ducting in proximity of the Pyrolysis Building, details not shown in
60% Drawings.
Dry Cake And Biochar Conveyance/Storage
o Dried Cake (DC) discharged from the sludge dryer provided by Centrysis
(DR-101) then will be grinded in a JWC grinder (G-801) and then enter a
conveyance system to transport DC to the new pyrolysis building for
storage, further processing, supersack bagging and/or hauling. DC will
enter a twelve (12) cubic yard (CY) live -bottom storage hopper (T-801)
provided by Austin Mac prior to entering the pyrolysis building. The
pyrolysis units (PYR-1 thru -3) provided by Bioforcetech will each process
DC to produce biochar. The biochar produced will then be conveyed to the
four (4) station supersack bagging system with integral scales (BS-1 thru
4) provided by Austin Mac for hauling containment. The conveyance
configuration has also been provided flexibility in operations which allows
for direct bagging of DC if bypassing the pyrolysis systems is ever
required or desired. The conveyance and storage system to be provided
by Austin Mac is to be comprised of one (1) bucket elevator (CVR-801)
and seven (7) shaft -less screw conveyors (CVR-802 thru -805; -901 thru -
904) that are oriented either horizontally or inclined. Additionally, ten (10)
airlock rotary valves (RV-801 thru -805; -901 thru -905) provided by Meyer
will be installed along the process for system isolation as required
between equipment and discharging locations.
o Conveyance Operational Process Flow: All DC transported by conveyance
from the dryer (DR-101) enters the DC storage hopper (T-801) through the
following equipment sequence:
o Conveyance operations from dryer (DR-101) to the storage hopper (T-
801):
DR-
RV-
G-
CVR-
CVR-
CVR-
CVR-
T-
101 --+
801 --+
801
801 —>
802--+
803--+
804--+
801
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
o Processing options: From the DC storage hopper (T-801) the DC can
either be processed in one of the pyrolysis units (PYR-1 thru 3) or bypass
pyrolysis. In both scenarios the conveyed material will transported to the
Biochar and DC load out conveyor (CVR-904) through the following
equipment sequences:
■ Process Option A - Produce biochar:
RV- PYR-
802--> 1
T- CVR- RV- PYR- CVR- CVR- CVR- CVR-
801 805 803, 2--). 901, 902, 903--� 904
RV- PYR-
804--* 3__�.
■ Process Option B - Bypass biochar production:
T-801 --> CVR-805--�- RV-805--> CVR-903--> CVR-904
• Hauling options: The biochar and DC material load -out conveyor (CVR-904) can
be operated to either fill supersacks in the bagging system with integral scales
(BS-1 thru 4) or continue to a rotary valve (RV-908) with a retractable discharge
chute on the discharge for loading material into a temporary hauling container
through the following equipment sequences:
o Hauling Option A - Bag material:
CVR-904
RV-901 —*
BS-1
RV-902-->
BS-2
RV-903,
BS-3
RV-904--+
BS-4
o Hauling Option B - Bypass bagging to loadout:
CVR-904---> RV-905
• Summarizing the above flow processes, there are four (4) operational methods
for DC handling after it has been conveyed from the dryer (DR-101) to the
storage hopper (T-801):
o Produce biochar, bag material for hauling (processing option A, hauling
option A)
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
o Produce biochar, bypass bagging for hauling (processing option A, hauling
option B)
o Bypass biochar, bag material for hauling (processing option B, hauling
option A)
o Bypass biochar, bypass bagging for hauling (processing option B, hauling
option B)
DC Storage Hopper
o The DC storage hopper (T-801) will be located outside the pyrolysis
building to the west and be fed by a shaft -less screw conveyor (CVR-804).
The storage hopper will be sized to hold approximately 13 cy of volume
that is based on the DC storage required during design solids production
that is in excess of one and a half (1.5) pyrolysis units in operation
operating at capacity with third unit is down. This corresponds to the
pyrolysis systems processing a maximum 600 wet pounds per day (Ibs/d).
The analysis assumed the minimum water content the pyrolysis system
can process which corresponds to 74 percent total solids (% TS) DC.
Table 1 provides the data for 1 day operation at design max month loading
where 13 CY would provide approximately 1.5 days storage for DC
assuming a bulk density of approximately 30 pounds per cubic foot
(Ibs/ft3).
Table 1
Storage Hopper Sizing
886
wet Ibs/d DC Total @ 74% TS
286
Ib/hr, excess (DC Total less capacity of two pyrolysis units)
9.55
ft3/hr @ 30 pcf, excess
8.49
CY, 1 day excess volume
o The hopper will be welded stainless steel construction, gasketed
connections, with a three screw configuration live hopper bottom, square
to rectangular in section with two sloping sides. The top will have a
flanged connection for the conveyor CVR-804 discharge and flanged
bottom connection for attachment to the transition chute for feeding CVR-
805. The live bottom shall be VFD controlled and capable of discharging
volumetric flow rates equal to the downstream conveyor CVR-805
volumetric flow range.
Rotary Valves
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
The conveyance system is to be relatively isolated from other equipment and
the atmosphere with Meyer HDX 8x8 drop -through rotary valves (RV-801 thru
-805; -901 thru -905). The direct drive rotary valves when actuated will drop -
through loaded material between isolated systems. The inlet and discharge of
the systems shall be 8" x 8", flanged cast iron housing, and a six -vane mild
steel rotor with chrome bore, stellite hard facing on rotor tips for abrasion
resistance. The capacity of each valve's through put shall be a minimum 1.5
times higher than the equipment feeding it, Table 2 below provides estimated
peak throughput with respective rotational speeds that will need to be
confirmed by both the rotary valve manufacturer and respective upstream
equipment manufacturer.
Table 2
Rotary Valve Capacity
Upstream Equipment
RPMs
Rotary Valve
@ 0.18 ft3/rev0)
EQPT Tag
Peak ft3/hr
RV-801
DR-101
31
4
RV-802
RV-803
CVR-805
59
8
RV-804
RV-805
RV-901
RV-902
RV-903
CVR-904
59(2)
8
RV-904
RV-905
NOTE:
(1) Cubic feet per revolution (ft3/rev) based on manufacturer data for
the Meyer HDX 8x8 drop-thru rotary airlock.
(2) During DC hauling operations when pyrolysis is bypassed.
• Conveyance
o Shaft -less Screw Convevors:
The shaft -less screw conveyors (CVR-802 thru -805; -901 thru -904) are to be
type 304 stainless steel construction, with thick ultra high molecular weight
(UHMW) polyethylene liners, and will operate on variable frequency drive
(VFD) motors. Rotational speeds will have an operational range of
approximately 9 to 39 revolutions per minute (RPM).
Accessories:
Each conveyor shall be provided with one (1) drainpipe with cap and
one (1) Tsubaki access door, to be located by Austin Mac.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
• Each motor shall include one (1) zero speed sensor and one (1)
emergency stop Allen Bradley cable pull switch provided by conveyor
manufacturer.
• The quantity of inlet and discharge chutes shall be provided by the
conveyor manufacturer as described in Table 3 and constructed of the
same materials utilized for the conveyors.
• CVR-901 shall be fitted with three (3) biochar quenching systems
spray nozzles located downstream of the PYR-1, -2, &-3 biochar
connection inlets. Quench system components and controls to be
provided by Bioforcetech and installed by the contractor. Each
quenching system will be controlled by a respective pyrolysis unit and
shall consist of thermocouple, solenoid valve and spray nozzle.
Conveyor manufacturer to provide nipples, ports, and/or connections
as required by Bioforcetech and located as required by Bioforcetech.
■ The DC volumetric throughput range capability for horizontally oriented
conveyors is approximately 13 to 59 cubic feet per hour (ft3/hr), respectively.
Inclining conveyors decreases volumetric throughput proportionally to the
angle. Due to the decreased capacity, all inclined conveyors transporting DC
are not to exceed 30 degrees inclination as this is anticipated to reduce
throughput by approximately 30% resulting in a maximum throughput of
approximately 41 ft3/hr per Austin Mac. Maximum DC production is not
anticipated to exceed approximately 31 ft3/hr, Centrysis to confirm.
Bucket Conveyor: The bucket conveyor (CVR-801) will be type 304 stainless
steel construction and transport material vertically from the discharge of the DC
grinder (G-801) to a shaft -less screw conveyor (CVR-802) overhead.
See Table 3 for conveyor equipment information.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Table 3
Conveyance Equipment Information
EQPT
Slope,
Hor.
Qty: Inlet/
Startup Ops(4)
Peak Ops(S)
Tags
Material (Orientation)
ft/ft(l)
LF(2)
Elevation(s) (3)
Discharge
CF/hr
RPMs)
CF/hr
RPM(6)
CVR-801
DC (vertical)
-
-
8.0
30.0
1/1
21
-
31
-
CVR-802
DC (horizontal)
0.11
26
28.0
30.8
1/1
21
14
31
21
CVR-803
DC (inclined)
0.16
70.6
29.0
40.2
1/1
21
15
31
23
CVR-804
DC (inclined)
0.16
30
38.2
1 43.0
1/1
21
15
31
23
CVR-805
DC (horizontal)(9)
-
51
28.8
1/4
59
39(7)
59
39(7)
CVR-901
Biochar (horizontal)
-
41
14.7
3/1
8
9(7)
11
9(7)
CVR-902
Biochar (inclined)
0.107
14.7
11.9
27.6
1/1
8
9(7)
11
11
CVR-903
Biochar and DC (inclined)(9)
0.38
16
25.3
31.4
1/1
8(8)
9(7)
11(8)
9(7)
CVR-904
Biochar and DC (inclined?)
0.38
28
29.2
40.2
1/5
8(8)
9(7)
11(8)
9(7)
NOTES:
(1) Approximate slope of conveyor.
(2) Approximate horizontal distance measured from center of first loading point to final discharge point.
(3) Approximate trough bottom invert elevation at center of loading/discharge point.
(4) Volumetric flowrates, cubic feet per hour (CF/hr), based on estimated startup average solids production and a DC bulk density of 30 pcf at 74% TS.
(5) Volumetric flowrates based on estimated design peak solids production and a DC bulk density of 30 pcf at 74% TS, CVR-805 flowrates based on
pyrolysis day hopper loading operation described herein.
(6) Revolutions per minute (RPM) based on Austin Mac design for horizontal 12-inch shaft -less conveyor throughput of 39 ft3/hr @ 26 RPM. For incline
RPM increase, a linear interpolation based on zero efficiency loss at a slope of zero and 30% efficiency loss at a slope of 0.58 (30 degrees) is applied
where RPMiNcuNED = RPMHORIzONTAL x (1+0.3*(slope/0.58).
(7) Shaft -less screw rotational speed limits based on Austin Mac's maximum of 1.5 times design speed (1.5 x 26 = 39 RPM) and the minimum as one third
design speed (26 / 3 = 9 RPM).
(8) CVR-903 and CVR-904 volumetric flowrates shown are for biochar production. When DC bypasses the pyrolysis units CF/hr and RPMs will be
increased to match CVR-805 throughput.
(9) When bypassing the pyrolysis units, the inclined conveyors CVR-903 & -904 will operate at approximately 20% higher speeds than the horizontally
oriented CVR-805 to maintain the same volumetric flow. If CVR-903 & -904 are operated at maximum speeds, 39 RPMs, the anticipated flow would be
approximately 49 CF/hr meaning a maximum speed of approximately 33 RPMs for CVR-805 during pyrolysis bypassing operations.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
• Preliminary Dry Cake and BioChar Conveyance Control Narrative
o One pyrolysis unit feeding operation
■ The level sensor in the pyrolysis unit that is online and operating will reach a
P-LOW LEVEL set point during operation or start up that will call T-801, RV-
802, CVR-805, and the respective pyrolysis unit's rotary valve to all turn on.
The volumetric flowrate to the pyrolysis unit online will start at XX ft3/hr
(Adjustable, default — 40 ft3/hr). When the level sensor of the pyrolysis unit
online reaches a P-HIGH LEVEL then T-801, RV-802, CVR-805 and the
respective pyrolysis unit's associated rotary valve will all turn off.
■ During one pyrolysis unit operation, the T-801 level will moderately fluctuate
as long as the pyrolysis unit can proportionally consume the current DC
production. If the T-801 level sensor reaches a HIGH LEVEL corresponding
to XX ft DC depth (adjustable, default — 2 ft) while conveying material, then all
conveyance equipment in operation will increase throughput XX %
(Adjustable, default - 10%). When T-801 level sensor reaches a HIGH LEVEL
corresponding to XX ft DC depth (adjustable, default — 03 ft) and conveyance
and pyrolysis units are operating at capacity then the operations will go to
multiple pyrolysis unit feeding operations.
o Multiple pyrolysis unit feeding operation
■ For multiple pyrolysis unit feeding operations the loading from the storage
hopper (CVR-805) will operate based on a "top off" operation of the
respective pyrolysis units. For top -off operations, any combination of Pyrolysis
units (PYR-1 thru -3) may be in operation. The following describes the
operational logic.
■ Two units: When one pyrolysis unit feeding is exceeded a level sensor in T-
801 will reach a HIGH LEVEL corresponding to XX ft DC depth (adjustable,
default — 03 ft) and will engage T-801 live bottom screws, RV-802, and CVR-
805 to turn on. The volumetric flowrate for two pyrolysis units online will start
at XX ft3/hr (Adjustable, default — 40 ft3/hr). The furthest pyrolysis unit online
(or being initiated) will turn on the respective rotary valve (after an adjustable
delay depending which upstream unit is online) allowing DC to fill the hopper
until the P-HIGH LEVEL sensor set point is reached at which point the next
pyrolysis unit online that is closer to T-801 will engage its rotary valve and
begin filling. The rotary valve of the further pyrolysis unit online will continue
to operate as material remains between the two rotary valves and CVR-805 is
on; the downstream pyrolysis unit level set point will account for this volume
remaining in CVR-805 between valves. The further downstream rotary valve
will stop after XX minutes (adjustable, default - 30 minutes). If the T-801 level
sensor reaches a HIGH HIGH LEVEL corresponding to XX ft DC depth
(adjustable, default — 03 ft) while conveying material, then all conveyance
14
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
equipment in operation will increase throughput XX % (Adjustable, default -
10%).
■ Three units: When T-801 level sensor reaches a HIGH HIGH HIGH LEVEL
corresponding to XX ft DC depth (adjustable, default — 04 ft) sensor when all
equipment online is operating at capacity then the operations will turn on the
third pyrolysis units rotary valve and begin filling the third pyrolysis unit for
operation as detailed above and volumetric flowrate for three pyrolysis units
online will start at XX ft3/hr (Adjustable, default — 40 ft3/hr). When all three
units are online and the equipment is all operating, if the T-801 level sensor
reaches the HIGH HIGH HIGHLEVEL all conveyance equipment in operation
will increase throughput XX % (Adjustable, default - 10%). If all equipment is
operating at capacity and the T-801 level sensor reaches a HIGH ALARM
LEVEL corresponding to XX ft DC depth (adjustable, default — 06 ft)
downstream production will decrease throughput XX % (Adjustable, default -
10%) and SCADA will alarm.
■ For any number of units online, after all pyrolysis units online have been filled
and the level sensor of the closest pyrolysis unit online reaches a P-HIGH
LEVEL then T-801, RV-802, and CVR-805 and the most upstream pyrolysis
unit's respective RV will stop. Note, at this point the excess material between
rotary valves should be emptied and the downstream rotary valve(s) will
already be off.
Decreasing DC Production
■ When two or three units are online theT-801 level sensor HIGH HIGH LEVEL
or HIGH HIGH HIGH LEVEL points respectively have not been signaled for
XX hours (adjustable, default 4 hours) then all conveyance equipment in
operation will decrease throughput XX % (Adjustable, default - 10%). After XX
hours (adjustable, default 12 hours) of no HIGH HIGH LEVEL or HIGH HIGH
HIGH LEVEL single one pyrolysis unit and associated rotary valve will go
offline and the remaining units will go to back to a volumetric flowrate of XX
ft3/hr (Adjustable, default — 40 ft3/hr) until only one unit is required for
processing DC in which case the operations will go default to the one
pyrolysis unit feeding operation
Volume Considerations
■ The estimated volume between rotary valves is based on 0.78 ft3 per foot
(Austin Mac to confirm) of CVR-805. Therefore, the associated level sensors
will account for approximately an additional 11 ft3 during operations as
described above between valves (twice the amount if PYR-2 is the only unit
offline). Note, each pyrolysis unit's day hoppers can hold up to approximately
67 cubic feet (500 gallons) of material. The above narrative is assuming
pyrolysis level sensors between LOW and HIGH LEVELS which correlate to
approximately 54 ft3 (2 CY) of DC fill in each Pyrolysis unit before stopping
15
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
the filling operations. At capacity a pyrolysis unit consumes approximately 10
ft3/hr (300 wet Ibs/hr DC at 30 Ibs/ft3); where, without additional DC being
added, a filled hopper would allow for approximately 5.4 hours of operation.
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City of Edmonds
WWTP Carbon Recovery Project
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Building Mechanical (F-, H-, PL- Sheets) by FSI Consulting
Engineers
• General
o The mechanical systems for the WWTP will consist of fire protection,
plumbing, process piping, and HVAC systems within the existing Solids
Process Building (SPB), the new Pyrolysis Building (PB), and two duct
connections to louvers on the Headworks Building west wall.
o Fire sprinklers will meet NFPA 13 and local requirements, and will include
wet systems for Ordinary Hazard Group 1 occupancies (0.15 GPM per
1500 sqft) with in the dryer room and the PB. There will be no
modifications made to fire protection within any other spaces beyond
these two. Based on NFPA 820, all equipment within the dryer room sub
room and Pyrolysis Building will be required to be Class II Div. 2.
o Plumbing systems will provide potable and non -potable water. The potable
water system will provide make-up to the Hydronic Heating Loop, two
emergency shower/eye wash in the SPB and an emergency eye wash in
the PB. Non -potable systems will serve the dryer and pyrolysis units, hose
bibs throughout the facility along with the fire protection system. The
existing compressed air system will be modified to serve the pyrolysis
units and the dust collector connected to the conveyors. Natural gas will
be provided to the boilers, pyrolysis units, make up air handlers (MAU)
and unit heater (UH). A new natural gas service to the building will be
required to handle the increased load due to added equipment.
o HVAC systems will maintain 65-degree temperatures throughout the dryer
room, the screening disposal room and PB. Indirect gas heating coils will
be used for all heating needs within the SPB because the existing
equipment that will be replaced has in direct gas heaters and this heating
modifications to the SPB is considered a maintenance upgrade. An
indirect gas UH will provide the heat to the screening disposal room.
Equipment within the dryer sub room and the PB will be required to be
Class II Div. 2 and Group G rated.
o The Hydronic Heating Loop serves the dryer and pyrolysis units. The new
waste disposal method will take processed waste and dry it with a dryer
into a flammable product called cake. A conveyor will transport the cake to
the new PB to be used as fuel for the pyrolysis units. The pyrolysis units
generate heat for the Hydronic Heating Loop. In addition, there are three
boilers that will generate heat for the Hydronic Heating Loop for use in the
dryers' hydronic coils.
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City of Edmonds
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Applicable Codes
o The following codes apply to the mechanical, plumbing, and fire protection
design:
0 2015 International Building Code with Washington State Amendments
0 2015 International Mechanical Code with Washington State Amendments
0 2015 International Fire Code with Washington State Amendments
0 2015 International Fuel Gas Code with Washington State Amendments
0 2015 Uniform Plumbing Code with Washington State Amendments
0 2015 Washington State Energy Code
0 2016 Washington State Boiler and Unfired Pressure Vessel Laws
0 2016 NFPA 13 Standard for the Installation of Sprinkler Systems
• Fire Protection
o Automatic sprinkler systems will be provided throughout the dryer room
and the PB in accordance with NPFA 13 and the local authority having
jurisdiction.
o The dryer room and the PB will have a wet pipe sprinkler system. The wet
system will be sized for Ordinary Hazard Occupancy. No other
modifications will be made to the existing building fire protection.
o Sprinkler heads will be semi -recessed pendant type with polished chrome
finish in all areas with suspended ceilings. Upright -type with rough bronze
finish will be used in all areas without drop ceilings.
o Two sprinkler branches will connect to the non -potable water riser for the
wet systems. Each will be complete with shutoff gate valve, alarm check
valve, water motor gong, and all required appurtenances.
o Interior piping will be black steel with screwed or grooved, coupled fittings.
All exterior piping will be galvanized black steel with screwed or grooved,
coupled fittings.
o The pyrolysis units will be provided with a 3/4" fire pipe connection and the
dryer with a 1" fire pipe for their internal sprinklers. Sprinkler coverage will
be required under the pyrolysis units, the dryer support structure and
under any ductwork 48" or wider.
o The fire protection contractor will provide hydraulic calculations, shop
drawings and responsibility for all permitting.
• Plumbing
• Potable Water and Non -Potable
o A potable water system will serve two emergency shower/eye wash
stations, the emergency eye wash station and a connection to the
Hydronic Heating Loop make up.
o Piping will be Type L copper tube and fittings with soldered joints.
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
o All domestic cold water piping in the building will have thick fiberglass
insulation with a vapor barrier jacket.
o Non- potable water will be provided to the dryer and pyrolysis units with a
direct connection and an exterior hose bib for washdown purposes.
• Hot Water
o A point of use hot water heater will serve the single eye/face wash station
in the Pyrolysis Building
• Compressed Air
o The existing compressed air system will be modified to provide 100 PSI air
to the three pyrolysis units and the dust collector with a direct connection
and exterior quick disconnect duplex at each unit.
o Schedule 80 black steel piping and fittings rated at class 150.
• Natural Gas
o A new 5 PSI gas meter will be provided to the facility by PSE in front of
Building 100. A 2" gas pipe will extend from this meter to feeds the PB and
extend through the SPB to the dryer room and boilers.
o Schedule 40 black steel piping and fittings rated for 150 PSI.
• Heating, Ventilating, and Air Conditioning (HVAC)
o Design Criteria
■ Outdoor design temperatures of 20°F DB in the winter (heating
season) and 84°F DB, 74°F WB in the summer (cooling) will be
used to size the system, as required by the Washington State
Energy Code (WSEC).
■ In the occupied spaces, the HVAC system will be designed to
maintain a setpoint of 65°F during heating season. There will be no
cooling or CO2 control.
■ The mechanical equipment within the dryer room and the PB will be
rated for Hazardous Group G and compatible with Class II Div. 2
electrical requirements. The design includes removal of all the
existing Exhaust fans and associated appurtenances in the
incinerator/dryer room. The louvers on the west wall will be
removed and replaced with a single 64" x 48" louver. The new dryer
room will be ventilated with 1100 CFM, being pulled through the
louver and exhausting with an exhaust fan at the South wall. There
will be a 100% outside air unit (MAU) that will deliver 5500 CFM of
makeup air to the dryers at a minimum of 59 degrees. The
ductwork will manifold up through the dryer slab with four
penetrations of 40" x 16". This ductwork will connect to the dryer at
a flange within 2" of the structural slab so that the duct section that
is closest to the dryer can be removed for maintenance on the
dryer. The dryer MAU and exhaust fan will be interlocked with the
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dryer. The MAU will enable with the dryer and the exhaust fan will
disable.
■ There will be an indirect gas -fired fan coil (DF) that will temper the
dryer room air and take air from the ceiling of the dryer room and
supply it down to the existing louvers at the floor level of the dryer
room. This unit will mix and temper the air and prevent stratification.
■ In the shop area the existing air handling unit has the gas heating
capacity to serve the shop area and has been confirmed to
function. There will be no changes to the shop ventilation or
heating. The existing welding hood exhaust fan duct work will be
disconnected from the roof hood in the dryer room and a roof hood
above the shop will be provided. A UH will be provided in the
screening room to temper the 500 CFM of OSA that is pulled
through that room by the odor control system.
■ The PB will have a 720 CFM indirect variable MAU. This unit will
have stand-alone controls connected to the pyrolysis units with a
current sensing relay and to the space with a pressure sensor. The
unit will maintain 65 deg F set point and ventilate the building and
provide the combustion air for the three pyrolysis units. The unit will
be variable flow to provide air volume based on the number of
pyrolysis units that are running, 240 CFM per pyrolysis unit.
■ All MAU and supply fans will have MERV 4 filters
o Ductwork
■ HVAC ductwork will be galvanized sheet metal.
■ All exterior duct work will be insulated per code and wrapped with
R-8.
• HVAC Piping
o Process Water System
■ The Hydronic Heating Loop will have two primary loops connected
to one large secondary loop. One primary loop for the boilers and
another for the pyrolysis units. The boilers will each be equipped
with a dedicated inline pump. The secondary loop will be for the
dryer, provide pressure for the pyrolysis loop and will have two
base mounted pumps sized for 200 GPM. There will be a heat
rejection fan coil sized for 1.4 MMBTU connected to the pyrolysis
loop that will be used to protect the pyrolysis units. This fan coil will
have a three-way control valve that is controlled based on the loop
temperature. The fan coil will be located on the exterior North side
of the SPB. All pumps will be located in the basement of the dryer
room. The primary loops will be 4" flanged black iron. The
secondary loop will be 6" flanged black iron.
W
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
■ The primary loop to the pyrolysis units will be routed along the north
side of the SPB to the PB and then over head above the pyrolysis
units and back along the north side of the SPD and then inside the
building through the concrete wall, a concrete support over a door
and into the dryer room. A bypass valve will be at the farthest point
in the PB.
■ There will be three Futera XLF 1750 boilers to generate the heat
needed to operate the dryer. Two of the boilers will meet the
system maximum demand of 3 MMBTU's and the third boiler is for
maintenance stand by. The boiler firing order will be rotated to have
equal run time of the three boilers. The boiler exhaust will be
combined and exit the building at the existing incinerator exit point.
The boilers will have direct vents to the West side of the dryer room
to the north of the new maintenance assess door. Each boiler will
have integral control valves that open when the boiler is enabled.
One control valve will always remain open to maintain minimum
flow through the boiler loop.
■ The dryer will be used to dry processed waste in order to be burned
in an oxygen -starved chamber within the pyrolysis units. The
maximum heating demand for the dryer is 3 MMBTU. The dryer
needs to modulate the heating hot water flow significantly to control
the temperature within each of the four dryer sections. The design
water temperature is 194 degrees F. The dryer will have a bypass
control valve at the furthest point of the secondary loop.
■ The Hydronic Heating Loop will be insulated per code. All exterior
pipe will be insulated per code and wrapped with two-piece
fiberglass ASJ/SSL-II insulation pipe.
• Exhaust requirements
■ A major requirement of the project is that any new exhaust
terminate at the same location the existing incinerator exhaust exits
at the SPB. Both the pyrolysis units and the boilers exhaust stacks
are required to discharge at this location and the discharge is to be
the same height and approximate velocity of 50 FPS. The boiler
and pyrolysis exhaust streams will not co -mingle in the flue but will
use the same exit location. The flues will connect to a custom ANSI
316 stainless steel exit point that has separation to prevent the two -
flue pressure's from affecting each other.
■ The three P-5 pyrolysis units will exhaust a max of 720 CFM
through a combined stack that will be routed along the north side of
the SPB and then inside the building through the concrete wall, a
concrete support over a door and into the dryer room. At this point
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City of Edmonds
WWTP Carbon Recovery Project
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the pyrolysis exhaust will route up to the existing incinerator exit.
The flue will be 12" diameter double wall ANSI 316 SS. The flue will
have a clean out and drain just outside the PB and at the flue exit
point in the SPB. The pyrolysis exhaust will also continually be
sloped to drains along the horizontal run in order to remove
condensate from within the flue. Condensate will be neutralized and
routed to nearest drain. The flue location on the North side of the
SPB will be coordinated with the conveyer belt and the hydronic
piping.
■ The boilers flues will be sized and combined per the Futera
manufacturer. The flue will vent at the existing incineration flue
location.
o Automatic Controls
■ HVAC automatic controls will be stand-alone P&ID. The Hydronic
Heating Loop will be stand-alone P&ID
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WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Structural (S-Sheets)
• Dryer Building
o The existing concrete cantilevered walkway and the platform at the shop
level and the platform's columns at the center of the current incinerator
room shall be demolished. The extent of the walkway demolition will only
be needed where the new platform will be located. This is being done to
seismically attach the new dryer platform to the existing concrete walls.
The remaining walkways will be able to remain.
o The new platform is expected to match the elevation of the existing shop
level. Therefore, the current doors that currently access the walkways will
still be able to be use. The platform will be constructed of a 4.5-inch
concrete fill over 3-inch steel decking that will be supported by structural
steel framing. We currently show steel columns all around the platform so
that we do not need to rely on connection plates attached to the existing
concrete walls for gravity support. The columns will extend to the
basement level. Because the existing basement level slab construction is
a thick concrete mat system, there will not be the need for additional
foundation upgrades. The column baseplates will be able to be placed
directly on the top of the basement slab. All steel framing shall be
galvanized.
o A new access platform will be located approximately at the elevation of the
7.31 ft level. Because the platform will primarily be for access, the floor
construction will be fiberglass grating over structural steel framing. The
framing will be supported by the dryer columns where accessible,
otherwise steel double angle hangers will be used. They will be supported
by the dryer platform framing above.
o A new smaller access platform will be located approximately at the
elevation of the 9.95 ft for maintenance access to grinder G-801. The floor
construction will be fiberglass grating over structural steel framing. The
framing will be supported by the dryer columns where accessible,
otherwise steel double angle hangers will be used. They will be supported
by the dryer platform framing above.
o Seismically, it is anticipated that the added mass from the dryer and new
platform will not trigger a full lateral analysis of the building. It is expected
that the existing concrete wall lateral system will have sufficient capacity to
resist the seismic demands from the new construction and equipment.
Given that, there is not any lateral system elements needed within the new
structural steel framing. The new concrete slab will be doweled with
reinforcing bars into the existing concrete walls to its transfer seismic
loading to the walls.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
• Pyrolysis Building
o The new Pyrolysis building will be a one-story structural steel structure.
The roof structure construction shall be 2.5-inch concrete fill on 2-inch
steel decking supported by steel beams. The concrete fill is needed to
define a rigid diaphragm at the roof to distribute the lateral forces to a
three -sided lateral resisting system. Conventionally, a lateral system
would be on all four sides of the building but with the large opening
requirements on the south side of the building this is not possible. The
lateral system will be comprised if special steel braced frames. They will
be located using the same columns which will support the roof framing.
All steel framing shall be galvanized.
o The foundation will consist of isolated and wall footings around the
building. The current understanding is that the footings will only be a few
feet below the new slab elevation. There are several footings that will be
adjacent to existing foundation walls of the solids handling building and a
clarifier basin. From preliminary analysis, it appears that the existing walls
have sufficient lateral capacity to resist any forces induced by the new
footings. to
o A limited access platform will be located within the building so staff can
move between the upper levels of the new equipment. The mezzanine
will be fiberglass gratings supported by steel framing. The framing will be
supported by hangers connected to the roof framing above.
o The floor construction will be a new concrete slab on ground. There will
be a base course and vaper barrier under the concrete slab. In addition,
there will be a partial pipe gallery/utilidor which will incorporate the large
existing piping that must remain in place during the construction. The
utilidor will be constructed will a concrete base under the existing pipes
and concrete side walls. Fiberglass grating shall be used over the utilidor.
Because of the width of the utilidor, there will be need for steel framing to
support the grating.
o To support the building enclosure system, horizontal wind girts will be
located around the building exterior where metal siding and translucent
panels exist. The girts will be located above and below translucent panels
and at 10 feet on center where the metal panels exist. Also, where the tall
translucent panels exist on the south side of the building, the wall girls will
be located at 10 feet on center behind the panels and will have
connections allowing the girts to be removed if the panels need to be
opened.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Civil (C-Sheets)
• Temporary Erosion and Sedimentation Control
o TESC protection in existing parking lot trench drain, and existing parking lot
catch basins and 2,d Ave S catch basins (three locations); silt fence around
work area along SR 104; high vis fencing around work area along SR 104
and parking lot entrance.
• Stormwater Collection and Conveyance
o Collect roof runoff from new Pyrolysis Building and route to existing 6" PVC
storm drain in front of Operations Building. Connect 4" metal interior
downspouts to 4" PVC downspout connectors at 2 locations; install 6" x 6" x
4" wyes and bends as necessary to connect to 6" PVC downspout collector
drains. Trench and install 155 LF of 6" PVC downspout collector drains, two
6" 45-degree bends, and two 6" x 6" x 6" wye; use one wye to cut -ins to
existing 6" PVC storm drain. Install two 6" PVC cleanouts at upstream ends
of downspout collector drains.
o Collect surface runoff from Parking Lot with replaced trench drain across
driveway entrance. Demolish 230 sq. ft of existing concrete slab, trench
drain, catch basin, valve, and associated piping around trench drain. Pour
new concrete slab, sloped to drain to new cast -in -place, reinforced trench
drain. Trench drain is 24-feet long, 10-inches wide, and approximately 12-
inches deep. Trench grate is 12-inch wide, Neena R-4990-CX Type P.
Bottom of trench drain will be sloped to drain to point over existing sanitary
side sewer. Connection to existing side sewer will require approximately 10-
feet of 6" Ductile Iron (DI) pipe spools, flanged 6" 45-degree DI bend, and
flanged 6" x 6" x 6" DI wye cut -ins to existing 6" DI side sewer. Connection
will include Titeflex CheckMate Valve with upstream clamp, to control odor.
• Parking Lot Grading and Paving
o Minor regrading in the parking lot outside of pyrolysis roll -up door, cutting
approximately 4". New asphalt paving of entire parking lot 5,500 sq. ft 4"
HMA CL'/2" PG 64-22. Demolish and replace 155 sq. ft of concrete
sidewalks and curbs in front of Headworks Building. Demolish and replace
230 sq. ft of concrete slab around trench drain, as described above.
• New Entrance Gates
o Demolish existing metal swing gates and install new metal roller gates. Install
two 14-foot wide by 6.5-foot tall powered rolling metal gates along west face
of existing entrance columns/light posts. Style and manufacturer TBD.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Electrical (E-Sheets)
General
o Coordinate work and sequencing with other trades.
o Provide polyvinyl chloride coated rigid metal (steel) conduit (PRMC)
systems for process areas. It is acceptable to provide compression fitting
electrical metallic (steel) tubing (EMT) or rigid metallic (steel) conduit in
the MCC and MCC/SCADA (formerly the Gym) room. Size conduit for
conductors and cables required unless noted otherwise. Provide up to 18
inches of liquid -tight flexible metal conduit for connections to vibrating
equipment.
o Provide XHHW or XHHW-2 insulation for single conductor wiring for
power, signaling, and control circuits. Provide Class B stranded
conductors for power circuits and provide class C stranded conductors for
signaling and control circuits. It is acceptable to provide solid core #10
gauge wiring for light and receptacle branch circuits.
o Provide tray rated instrument cable (TC or TC-ER) with individual shielded
pairs for analog signals (e.g., 4-20 mA). An overall shield is acceptable for
each triad of one or more triad grouped conductor cables.
o Provide VFD cable for motor branch circuits where the motor is controlled
by a VFD. Provide Belden's symmetric 100% ground cable in the size
required for motor horsepower. Provide cable from electrical distribution to
motor via motor disconnect switch in conduit sized for cable.
o Provide heavy-duty, 304 stainless steel NEMA 4X enclosure, disconnect
switch.
■ Provide non -fusible for each phase conductor with at least one
auxiliary contact unless noted otherwise.
■ Provide switches suitable for environment. Provide explosion proof
disconnect switch if required by environment.
o Provide NEMA 4X or NEMA 7/8 control stations, oil resistant pushbuttons,
lights, potentiometer, and selector switches per environment. Locate
control station at ground level near and within sight of associated motor.
Provide conductors in conduit from new motors to MCC
o Provide NEMA rated enclosures:
■ Provide NEMA 1 or NEMA 12 is acceptable for MCC Room and
MCC/Control Room.
■ For areas classified as hazardous, provide explosion proof or other
enclosure methods suitable for installation in such environment.
■ Provide NEMA 4X, 304 stainless steel for areas not indicated
above.
o Provide Category 6 communications cable for network communications
(Rockwell Automation Ethernet IP, ethernet, etc.).
■ Provide OSP rated cable where routed below grade.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
■ Provide 600V (AWM) jacket cable where any portion of cable
routes in same cabinet or wire way with conductors power at more
than 200 volts above ground.
■ Route Category 6 communications cables in separate raceways
from power circuits and discrete (on -off) signaling circuits; it is
acceptable to route analog signal cables in common raceways.
o Provide new lighting fixtures, suitable for wet locations
■ Provide luminaires suitable for Class 1 or Class 2 hazardous by
explosive atmosphere environments as applicable.
■ Provide fixtures suitable for use with plant standard Green Creative
16T8/4F/850/BYP LED light bulb (T8 fluorescent bulb replacement
kit). Modify light fixtures as required.
■ The Owner prefers the T8 replacement LED light bulb. The Owner,
however, does not have a preference in lighting fixture
manufacturer.
MANUFACTURER
PART NUMBER
FIXTURE DESCRIPTION
A2
Lithonia
FEM4 2 32 BMPCL MVOL
4FT X 1 FT, white reflector,
Green -Creative
T8 17W 4FT (LED)
Polycarbonate lens, white, 2 T8 bulb
modified for single ended LED tube,
vapor -tight, wet location, Mounting
hardware as required
Provide LED in tube compatible with
fixture wiring
A3
Lithonia
FEM4 3 32 BMPCL MVOL
4FT X 1 FT, white reflector,
Green -Creative
GEB10PS
polycarbonate lens, white, 2 T8 bulb
T8 17W 4FT (LED)
modified for single ended LED tube,
vapor -tight, wet Location, Mounting
hardware as required
Provide LED in tube compatible with
fixture wiring
XP2
Holophane
HFL L 2 U
Class I, Division 2, Group D, Class
Green -Creative
T8 17W 4FT (LED)
II, Division 2, Group G Rated
Fixture.
2 Lamp T5, 120VAC. Wire guard,
Polycarbonate lens, mounting as
required.
XP3
Holophane
HFL L 3 U
Class I, Division 2, Group D, Class
Green -Creative
T8 17W 4FT (LED)
II, Division 2, Group G Rated
Fixture.
3 Lamp T5HO, 120VAC. Wire guard,
Polycarbonate lens, mounting as
required.
FF
Holophane
W4GLED 10C1000 40K T3S
Glass lens wall pack, Wet location,
MVOLT SPD PE LWG BZSDP
3400 Lumen, 4000K color, short
distribution, bronze finish, wire lens
guard.
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City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Headworks Building
o Replace conductors between screenings conveyor control station, drive,
motor controller and control panel. It is acceptable to reuse existing
conduit where feasible and the conduit appears in good condition.
o Provide new VFD in existing MCC for screenings conveyor. Provide line
reactor and load reactor. Extend existing control conductors from existing
conveyor motor starter to new VFD.
o Reconfigure existing motor starter for Grinders.
o Provide new size 2 motor starters in existing MCC for both new
screenings pumps. Match control circuits and extend from control panel as
required.
Solids Handling Building
o Ensure continuity, for as much as practical, for Critical process loads. The
following loads will need to be maintained as operational as much as
feasible.
■ (CD-201) Primary Clarifier No.1
■ (CD-202) Primary Clarifier No.2
■ (CD-203) Primary Clarifier No.3
■ (CD-204) Primary Clarifier No.4
■ (FAF-201) Primary Clarifier Exhaust Building
■ (IP-601) Building Power Transformer
o Provide new MCC 601A feeder circuit (3 sets, each 4", 4-350kcmil &
1#2/OG) from existing switchboard 301 (side B) to existing MCC 601.
Existing conduit from location of new Pyrolysis building to MCC 601A may
not be usable. It is acceptable to reuse existing conduit.
o Existing MCC 601A and MCC 601 B modifications
■ Provide ten (10) starters for 1/3 HP rotary valves in existing MCC
601A (along wall) and MCC 601 B (freestanding). Configure motor
starting circuit to accept remote run signal from PLC 600. Provide
Class II, Division 2 rated control stations for each valve routed to
individual MCC unit.
o New 1200A Switchboard
Provide new 480 volt, 3 phase, 4 wire plus ground, 1200 Ampere
(A) power feeder from existing Switchboard SB301 (near primary
clarifiers) to new 1200 Ampere Switchboard.
Provide 1200 ampere, 3 phase, 4 wire plus ground, 480 volt
switchboard.
Provide the following circuit breakers
• 1200A main circuit breaker (Provide current transformer for
each phase and neutral for Active Harmonic Correction
Unit), Ground Fault trip unit, zone selective interlock
• 450A "Sludge Drier", Ground Fault trip unit, zone selective
interlock
300A "Harmonic Correction Unit"
E*
W
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
• 400A "MCC 602"
• 80A "Dust Collector"
• 200A "Sludge Drier Odor Control"
• 90A "Boiler Control Panel"
• 100A "PYR-1 Pyrolysis"
• 100A "PYR-2 Pyrolysis"
• 100A "PYR-3 Pyrolysis"
• 20A "Screening Compactor"
• 30A "Transformer T LA-602"
• 20A "HVAC MAU-1 Drier Room Air Handler"
• 20A "HVAC MAU-2 Pyrolysis Air Handler"
New Active Harmonic Filter
■ Provide a filter with at least 200 amperes of harmonic correction
capacity. Provide control and monitor system capable of reporting
status using Rockwell Automation (Allen Bradley) Ethernet IP.
New MCC 602
■ Provide new 12 section, back to back, motor control center (MCC).
Provide the MCC with 480 volt, 3 phase, 3 wire plus ground, 600
Ampere (A) horizontal bus, 300A vertical bus.
■ Provide 400 ampere, 3 phase, 3 wire plus ground, branch circuit
from new switchboard to new MCC. Provide Type 2-B wiring.
Provide MCC manufactured by Rockwell Automation
(Allen-Bradley), Eaton Electrical (Cutler Hammer), or Schneider
Electric (Square D)
■ Provide network switch in MCC with capacity for each motor
controller, two uplink ports (to Plant's SCADA network), and at least
15% spare network ports.
o Switches must be Cisco Systems IE3000 series or Stratix
5700 (with Cisco IOS operating system); no other switch
manufacturer will be acceptable.
o Provide USB type A or C pass -through port such that a
technician may connect to the network switch without
exposure to energized equipment.
o Provide through -door power disconnect for network
equipment.
■ Provide MCCs with seismic bracing suitable for installation location.
o Provide MCC as at least 16" deep, freestanding unit.
o Provide MCC-601 B as back to back mounting units.
■ Provide MCC mounted circuit breakers with through door operators.
o Provide adjustable trip, long, short, and instantaneous for
main and feeder circuit breakers larger than 200 amperes.
29
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
o Motor circuit protectors with adjustable instantaneous
pickups are acceptable for motor controllers if part of a listed
motor branch protection circuit.
o Fusible switches are not acceptable unless noted otherwise.
o Provide amperage metering for each phase for circuit
branches larger than 200 amperes.
■ Metering shall capture RMS amperage, one second
resolution with storage capacity of at least 31 days.
■ Metering shall be accessible through ethernet
interface.
Provide NEMA style motor starters, minimum size 1. Provide power
supply or CPT with unit circuit breaker. For each motor starter,
provide electronic overload with ability to monitor overload status
(motor ampere per phase, line voltage, loss of phase, fault code)
using Rockwell Automation (Allen-Bradley) Ethernet IP protocol.
Provide Ethernet IP solid state overload relays for use with
contactor -based motor controllers. (Full voltage, non -reversing; Full
voltage, reversing)
o Overload relay must be controllable through Rockwell
Automation Ethernet IP interface implemented to be
compatible with plant's standard ControlLogix PLC controller
platform.
o Overload relay must provide the following statistics:
■ Motor runtime
■ Motor start count
■ Motor amperage per phase at a resolution of at least
once a second
■ % of motor thermal capacity (e.g., % to tripping on
overload)
■ Overload status (tripped, not tripped, running, not
running, etc.)
■ Overload trip code
Provide Ethernet IP variable frequency drives.
o VFD must be controllable through Rockwell Automation
Ethernet IP interface implemented to be compatible with
plant's standard ControlLogix PLC controller platform.
o VFD must provide the following statistics:
■ Motor runtime
■ Motor start count
Motor amperage per phase at a resolution of at least
once a second
% of motor thermal capacity (e.g., % to tripping on
overload)
VFD status (Faulted, ready, running, not running, etc.)
30
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
■ Fault code
■ VFD main power DC bus
■ Speed setpoint feed back
■ Motor voltage
o Provide output reactor unless noted otherwise.
o Provide 5% line reactor (combination of line reactor and DC
choke is acceptable)
o VFD must be one of the following and manufactured by the
same entity as the MCC:
■ Schneider Electric Altivar 61/71
■ Rockwell Automation PowerFLEX 755
■ Eaton Electrical PowerXL DG1
■ Provide the following units in the new MCC 602:
0
400A main circuit breaker
o
"CVR-801 Bucket Elevator" 8A, VFD (HD),
5% line reactor,
load reactor
o
"CVR-802 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-803 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-804 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-805 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-901 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-902 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-903 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
"CVR-904 Screw Conveyor" 8A, VFD (HD),
5% line reactor,
dV/dt filter
o
T-101 Water Pump" 35A, VFD (ND), 5% line reactor, dV/dt
filter
o
T-102 Water Pump" 35A, VFD (ND), 5% line reactor, dV/dt
filter
o
T-103 Water Pump" 2HP, FVNR
o
T-104 Water Pump" 2HP, FVNR
o
T-105 Water Pump" 2HP, FVNR
o
"G-801 Pyrolysis Grinder" 10HP, FVNR
o
7-701 Dried Cake Hopper Agitator" 10HP,
FVNR
o Suggested sequence building
31
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
■ The following is a suggested sequence of work for Solids Handling
Building. It is acceptable to modify the sequence with approval of
the Owner.
■ Install new 1200 ampere feeder from existing 1200 ampere frame
circuit breaker in Switchboard SW301 B. Provide and configure new
trip unit and trip sensor if required.
■ Provide 1200A switchboard and feeder from Switchboard 301.
■ Provide 400A temporary power feeder from 1200A Switchboard to
MCC 601A. Use circuit breaker
■ Relocate MCC 601 feeder pull hole (under proposed pyrolysis
building). Extend existing conduits under pyrolysis building.
■ Provide power, signaling, control and power branch circuits to
existing motors, new motors, existing to remain equipment, and
new equipment motors to new motor controllers.
■ Connect motor controllers and equipment to ethernet network.
■ Demonstrate motors will operate in HAND mode operation.
■ While operating in hand, verify statistics, such as motor amperage,
ambient temperature, thermal capacity (e.g., % to tripping on
overload) are available through the Ethernet interface.
■ Demonstrate motor contractor closed or motor operating feedback
is available.
■ Demonstrate motors will operate by command from PLC through
communications network.
■ Demonstrate VFD operating speed is adjustable by the PLC if
indicated.
■ It is acceptable for the Vendor to demonstrate the motors controlled
by the Vendor -furnished control panels.
■ Provide signaling and controls circuits to existing to remain and
new control panel enclosures and instruments.
■ Replace all light fixtures in the MCC room, solids drying room,
screenings room.
■ Provide circuits to building systems, like HVAC, lighting controls,
signaling, for new equipment in building.
Pyrolysis Building
o Provide 2 - Category 6 cables to each of the three pyrolysis units.
o Provide power branch circuits for conveyors, pyrolysis unit, loader, lights,
HVAC equipment.
o Provide lighting for structure.
o Provide circuits to building systems, like HVAC, lighting controls, signaling,
for new equipment in building.
480-208/120 Power Transformer
o Provide 30 kVA, 480VAC to 208/120Y power transformer. Provide branch
panelboard downstream of transformer with 3P-100A main circuit breaker
and 42 pole spaces with 1 P-20A circuit breaker for each pole space.
32
City of Edmonds
WWTP Carbon Recovery Project
DRAFT - Intent of Design Narrative
Architectural (A -Sheets)
• General
o The new Pyrolysis building will be approximately 2,700 gross square feet.
The new building will house three pyrolysis system components and an
area for storage of super sacks for the Edmonds Wastewater Treatment
Plant Carbon Recovery.
Architectural Concept
o The architectural design concept of the Pyrolysis building is guided by the
following fundamental considerations:
■ The Pyrolysis building is part of a permanent public works facility
and is expected to have a long useful life of 40-years, making
durability, low maintenance costs and moderate life -cycle costs
important considerations in the design and choice of materials and
finishes.
• Building Envelope
o Roof Profile - The roof is a conventional low sloped membrane roofing to
minimize the overall height of the building. The roof slopes are moderate
(0.25:12) and will be sloped by the structure to roof drains which are run
inside the building and then tight -lined to the existing stormwater
conveyance system. There will be overflow drains that will spill out at 18-
inches above grade for easy identification of a backup at the roof drain.
o Natural Light and Glazing - Translucent panels are being used to naturally
light the space as much as possible. Translucent panels are oriented
along the south fagade of the building to use them as a removeable panel
option when work needs to be completed on the pyrolysis system
equipment. There will also be selected areas of translucent panels along
the north fagade for addition lighting and the east fagade to break up the
large wall of metal panels that the neighborhood will see.
o Exterior Materials - The exterior of the building is largely composed of
three materials. These materials are horizontally -oriented metal siding,
translucent panels and concrete. The translucent panels will be
constructed so if needed in the future they can be removed independently
to provide access to the pyrolysis equipment.
o Interior Materials - The interior of the building will be exposed to the
existing adjacent structures where the buildings meet. Above the existing
buildings or where there is not an adjacent building, the interior will be
exposed girts and liner panels at the base up to 10-foot above finish floor
for a clean finish look at floor level.
33