Document nmvp3Rgn1jy9gqDqg230ZJrD1
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Interoffice Communication
j0 : Distribution From S B. Vick Date i February 24, 1982 Subject EMISSIONS RECOVERY SYSTEM REVISIONS
Attached is the Class A process design to improve the operating performance of the emissions recovery system. The revisions outlined in the process design include: (1) replacement of the existing Nash H-5 vacuum pumps, (2) replacement of the existing Nash 1253 compressors with new Nash 1253C compressors, (3) two interstage control loops, one to prevent high pressure (greater than 5 psi) and one to prevent low pressure (less than 1 psi) on the compressor suction, (4) instrumentation to start/stop the space vacuum pump/compressor train upon high system pres-
, (5) a spare compressant seal water pump, (6) a spare compressant water filter, (7) replacement of the existing Fisher Porter compressant water flow controllers with Universal Flow Monitor flow switches, and (8) placement of the mechanical seal flush system. Please review the design and prepare any questions and comments. The review meeting for this design will be held
Bruce Vick Process Engineer rah c: JF, CRM, RAF, PEM, SJV, AHS, JAD(2), VEM, VLT, JLH, RR, MPB
VAB.0001102892
A
EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant February 25, 1982
WORK BY: ______________________ Bruce Vick Process Engineer
REVIEWED BY: ____________________________ V. E. Messick Sr. Process Engineer
APPROVED BY: ______________________________ R. A. Frohreich Chief Process Engineer
VAB.0001102893
Aberdeen Chemical Plant Table of Contents
I. Purpose of Design II. Design Basis III. Process Description IV. Equipment Specifications
V. Instrument Specifications VI. Process Piping Schedule VII. Work List VIII. Drawings
VAB.000110289.4
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
I. Purpose of Design
The overall objective of this design is to provide a system capable of maintaining negative pressure (15 IN.Hg vacuum gauge) on all VCM emission sources with minimal operator attention. The VCM emission sources in cluded in the overall scope of the system are: (1) VCM tank farm, (2) VCM railcar unloading lines, (3) batch water strippers, and (4) vessel purge systems.
The motivation for providing a
capable or maintaining negative
pressure on the
mentioned above is: (1) to reduce operating per
sonnel exposure to VCM, and (2) to insure EPA compliance with the VCM
standard.
VAB.0001102895
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
II. Design Basis
The emissions recovery system is designed to recover VCM from the following areas:
(1) VCM Tank Farm (2) VCM Railcar Unloading Areas (3) Batch Water Strippers (4) Vessel Purge System
Syste
Receiver Draining (Old & New Unit) VCM Unloading Lines Batch Water Strippers Tank Farm Compressors
TOTAL
Flowrate (SCFM) MAX 60
10 Nil 130 200
The capacity required for effective operation of the system is approximately
200 SCFM.
J
VAB.0001102896
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EMISSIONS RECOVERY SYSTEM REVISIONS
Aberdeen Chemical Plant
III. Process Description
The emissions recovery system is designed to operate continuously with little operator attention. The system pressure will be maintained at 15 IN.Hg vacuum gauge.
Two new vacuum pumps, P-301 and P-302, and two new compressors, C-301 and C--302, will be provided in the system. One vacuum pump and one compressor will operate simultaneously as a train. The vacuum pump will operate at a capacity of 185 SCFM at 15 IN.Hg vacuum and the compressor at 175 SCFM at 110 psig discharge pressure.
Two interstage control loops are provided in the system to prevent either the vacuum pumps and/or the compressors from operating beyond their respective design conditions.
The first control loop is a feedback control loop to prevent high pressure (greater than 5 psig) at the compressor(s) inlet, sensing element, FT-301, senses the pressure and transmits a signal to pressure indicating controller, PIC-301, to create a response to the high pressure at the inlet of the compressors. As the pressure in-
the response of PIC--301 is to close; therefore, restricting vapor flow and creating a false vacuum at the inlet to the vacuum pump The reduction in the number of moles of vapor flowing from the vacuum pumps to the compressors allows the compressors to essentially "catch up"; the pressure at the inlet of the compressors will go down. PT-301 will sense the pressure reduction and allow PIC-301 to open allowing normal flow through the svstem.
The second control loop is also a feedback control loop. This control loop prevents low pressure (pressures equal to or less than 1 psig) at the inlet of the compressor(s). Pressure transmitter, PT-302, senses low pressure and sends a signal to pressure indicating controller, PIC-302. PIC-302 is normally closed and the response to the signal from PT--302 is to open. As PIC--302 opens, vapor flows from the dis charge of the compressors to the inlet of the compressors. The vapor flow from the compressor discharge to the compressor inlet will con tinue until an increase in pressure is sensed by PT-302. PT-302 will transmit a signal to PIC-302 and PIC-302 will close. The increase in pressure indicates matched flow between the vacuum pumps and compress--
VAB.0001102897
III. Process Description (cont'd)
A
As mentioned above, one vacuum pump and one compressor will operate as a train. To insure constant vacuum in the Emissions Recovery System, instrumentation is provided to start/stop the second vacuum pump/com pressor train.
Upon high pressure (5 IN Hg vacuum) in tank, T-701, high pressure switch, PSH--301, will start the vacuum pump or compressor not on stream. As the system pressure is reduced to setpoint (15 IN.Hg vacuum), low pressure switch, PSL-301, will stop the vacuum pump/com pressor train brought on stream as a result of high system pressure.
Control valves are provided on the suction lines on each vacuum pump and compressor, and the compressant seal water lines. These control valves are wired into the motor run circuit of the corresponding vacuum pump or compressor. When a vacuum pump or compressor is started and brought on stream, these valves will open, and when the vacuum pump and compressor is stopped, the corresponding control valves will
New compressant seal water pump, NP-301, will be added to the existing closed loop compressant seal water system as a spare to the existing equipment.
NP-301 will have the capability of supplying compressant seal water to the two new vacuum pumps, P-301 and P-302, and new compressors, C-301 and C--302. NP--301 will take suction off the vacuum pump knockout pot, T--702, and discharge into line 2--HM--328. The compressant seal water will be filtered through the existing seal water filters. The filtered compressant seal water will flow from the filter to the existing com pressant seal water coolers. Modifications to the inlet piping of the compressant seal water coolers is to be made to allow the coolers to be used in parallel. The modifications to be made involve the installa tion of two manual valves in the cooler bypass lines. (See Sketch on Figure 2). The compressant seal water flows from the coolers back to the vacuum pumps and compressors to form the liquid ring in these machines.
The existing Fisher Porter compressant flow controllers will be re placed with Universal Flow Monitor flow switches. A globe valve will be installed upstream of the flow switch and set to provide the re quired flow to the vacuum pump or compressor. If the flow falls be low the required compressant seal water flow, an alarm will sound notifying the operator attention is required to correct the flow.
The existing mechanical seal flush system will be replaced with a new mechanical seal flush system. The new system will be piped with stain less steel from the HPSW filter up to the mechanical seal flush inlet port on the vacuum pumps and compressors. The rotameters to be in stalled in this service are to be insulated and steam traced to pro vide adequate freeze protection. This will keep the rotameters from bursting and allow a continuous flow of seal water to the double me chanical seals on P--301, P--302, C--301, & C--302 during cold temperature conditions.
VAB.0001102898
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
IV. Equipment Specifications
Item No.
Service
C-301 C-302
Compressor Compressor
NP-301
Compressant Seal H^O Pump
P-301 P-302
Vacuum Pump Vacuum Pump
Location
Emissions Recovery Sys. Emissions Recovery Sys.
2-HM-327
3-HM-301 3-HM-303
*
VAB.0001102899
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
V. Instrument Specifications
Item No.
Service
CV-301 CV-302 CV-303 CV-304 CV-305 CV-306 CV-307 CV-308 CV-309 CV-310
On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve On/Off Control Valve
FA-301 FA-302 FA-303 FA-304
Flow Alarm Flow Alarm Flow Alarm Flow Alarm
FI-301 FI-302 FI-303 FI-304 FI-305 FI-306 FI-307 FI-308
Flow Indicator Flow Indicator Flow Indicator Flow Indicator Flow Indicator Flow Indicator Flow Indicator Flow Indicator
FS-301 FS-302 FS-303 FS-304
Flow Switch Flow Switch Flow Switch Flow Switch
PCL-301 PCL-302 PCL-303 PCL-304
Pressure Regulator Pressure Regulator Pressure Regulator Pressure Regulator
PIC-301 PIC-302
Pressure Controller Pressure Controller
Location
3-HM-301 3-HM-303 C-301 Inlet C-302 Inlet P-301 Seal ICO Line P-302 Seal ICO Line C-301 Seal ICO Line C-302 Seal ICO Line 2-HM-332 1 2-HM-333
Vinyl Control Room Vinyl Control Room Vinyl Control Room Vinyl Control Room
%-WP-310 ^-WP-314 ^-WP-315 Js-WP-311 %-WP-316 J5-WP-312 Js-WP-317 ig-WP-313
P-301 Seal ICO Line P-302 Seal ICO Line C-301 Seal ICO Line C-302 Seal ICO Line
^f-WP-310 %-WP-311 *5-WP-312 %-WP-313
Vacuum Pump Suction Compressor Discharge
VAB.0001102900
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
Instrumentation Specifications (cont'd)
Item No.
PG-301 PG-302 PG-303 PG-304 PG-305 PG-306 PG-307 PG-308 PG-309 PG-310 PG-311 PG-312 PG-313 PG-314 PG-315 PG-316 PG-317 PG-318 PG-319 PG-320 PG-321 PG-322 PG-323 PG-324 PG-3 2 5 PG-326 PG-327 PG-328 PG-329 PG-330 PG-331
Service
Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge Pressure Gauge
Location
P--301 Seal H0 Line P-302 Seal H^0 Line C-301 Seal H^0 Line
C-302 Seal H-0 Line %-WP-310 %-WP-311 ^-WP-312 Js-WP-313 3-HM-301 3-HM-302 3-HM-303 3-HM-304
C-301 Suction C-301 Discharge C-302 Suction C-302 Discharge
%-WP-318 %-WP-319 ^-WP-320 %-WP-321 Js-WP-322 %-WP-323 Jg-WP-324 ig-WP-325 3/4-WP-306 3/4-WP-306 3/4-WP-307 3/4-WP-309 Existing Seal H,,0 Pump Existing Seal H0 Pump 2-HM-328 1
PSH-301 PSL-301
PR-301
R0-301 RO-302
High Pressure Switch Low Pressure Switch
Pressure Recorder
Restriction Orifice Restriction Orifice
T-701 T-701
Emissions Recovery Sys
2-HM-332 2-HM-33 3
VAB.0001102901
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
V. Instrumentation Specifications (contfd)
Item No.
Service
SW-301 SW-302 SW-303 SW-304 SW-305 SW-307
Hand/Off/Auto Switch Hand/Off/Auto Switch Hand/Off/Auto Switch Hand/Off/Auto Switch
On/Off Switch On/Off Switch
Location
P-301 P-302 C-301 C-302 Existing Seal H2 Pump NP-301
VAB.0001102902
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EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
VI. Process Piping Schedule
The following piping schedule uses a system of numbers and letters as a line designation. This system denotes the following information: line size, service, line number, insulation requirements, and piping specifi cations.
Sample Line Designation 1-HM-326-N-A2-3
Piping Specification
*
Insulation Requirement
Line Number
Service
Normal Size, Inches
Sample Piping Specification A2-3
Third Specification of A2 Group Piping Material Nominal Pressure Rating
Service Designation Used
Designation
HM WP
Insulation
N S
Service Miscellaneous Hydrocarbons High Pressure Service Water
No Insulation Required Steam Trace
VAB.0001102903
EMISSIONS RECOVERY SYSTEM REVISIONS Aberdeen Chemical Plant
A
VII. Work List
1. Purchase and install new vacuum pumps, P-301 and P-302.
2. Purchase and install new compressors, C-301 and C-302.
3. Tie lines 3--HM--301 and 3--HM--303 into the existing vacuum pump inlet piping.
4. Run line 3-HM-302 from P-301 discharge to the existing inlet flange on the vacuum pump seal water separator.
5. Tie line 3-HM-304 into line 3-HM-302.
6. Purchase and install new pump, NP-301.
7. Tie line 2-HM--327 into the existing suction piping of the existing seal water pumps off T-702.
8. Tie line 2-HM-329 into the existing discharge piping of the exist ing seal water pumps.
9. Modify inlet piping to existing seal water coolers. (See figure 2)
10. Replace the existing compressant seal water flow controller with the Universal Flow switch.
Install CV-303 and CV-304 in the existing piping to the new cora, C-301 and C-302.
12 Install CV--305, CV--306, CV--307, and CV--308 in the compressant
water lines to the new vacuum pumps and compressors. 13 HM
compressor inlet manifold. 14. HM
15. Install PIC-301 in the existing inlet line to the suction of the vacuum pumps.
16. Install PSH--301 and PSL--301 on existing knockout tank, T--701.
17. Install the new stainless steel mechanical flush system with in strumentation.
18. Check all piping downstream of the compressors in VCM service for Pluggage (VCM polymerization, pipe scale, etc.). Any obstruction found in the line is to be cleaned and removed from the line.
VAB.0001102904
W mmm