13044
Title
11 Primary Clarifier Start Up
Starting up a clarifier involves putting the scum collector and sludge collection units into service. Also, open the valves on the primary sludge piping. Once in service, the associated equipment runs continuously.
SOP Identification Number
SOP Identification Number:
1100_Start Up
Purpose and scope
Purpose and scope:
The number of clarifiers in service will generally depend on flow volume and process conditions. Determine how many clarifiers are to be in service before starting the Procedure section of this SOP.
Health & Safety Warnings
Health & Safety Warnings:
Watch for open tanks, vaults and channels when covers are removed. Install cones at opening if covers are to remain off. If working on or near equipment, watch for rotating parts.
Cautions
Cautions:
- Ensure that adjustments to valves, drives, pumps, etc., all correspond to the clarifier put into service.
- Do not open the influent valves 100% until clarifier flows and levels have stabilized.
- Don’t allow “new” flows to rob flows from clarifiers already in service, which could upset downstream processes.
- Make sure the influent gates valves are fully open after the clarifier is full. If they are not 100% open, the clarifier can go septic.
- Ensure that information is recorded to the log book.
Potential Interferences
Potential Interferences:
Too high flows to the "new" clarifier can impact downstream processes.
Personnel Qualifications
Personnel Qualifications:
Operator I, knowledge of primary treatment process and SCADA controls.
Equipment, Supplies, Required Tools
Equipment, Supplies, Required Tools:
Valve keys or other tool to open and close valves.
Quality Control/Quality Assurance Activities for the Procedure
Quality Control/Quality Assurance Activities for the Procedure:
- Record activity to log book.
- Self-check of clarifier being put into service with associated equipment and systems that are affected.
- Monitor process to make sure flows are not robbed from the clarifier(s) that were already on line.
- Make sure gate valves are 100% in order to avoid septic conditions.
Procedure
Procedure:
Steps 1 – 3 take place “upstairs” at the Primary Clarifier Deck.
1. Prepare the Clarifier and Open the Channel:
a. Inspect the clarifier to be put into service for ladders, tools, blocking, etc., that need to be removed.
b. Identify the influent slide gates that are associated with the primary clarifier being put into service {tag nos. 1101VLV1181B, 101VLV1182B, 101VLV1183B, 101VLV1184B, 101VLV1185B}. Depending on the primary clarifier, there will be a minimum of two gates or a maximum of three gates. Remove those slide gates and allow influent to the channel directly in front of the primary clarifier that is being put into service.
c. Identify the two influent valves {tag nos. 1101VLV1181 & 1101VLV1181A, 1101VLV1182 & 1101VLV1182A, 1101VLV1183 & 1101VLV1183A, 1101VLV1184 & 1101VLV1184A, 1101VLV1185 & 1101VLV1185A} associated with the primary clarifier being put into service. Remove aluminum grates to gain access to the valves stems. Manually open the valves with the T-handle valve key by turning counter-clockwise. Do not open all the way. Open until you hear flow entering the clarifier.
d. Remove an aluminum cover from the primary clarifier so the water level can be monitored. IF THE COVER IS TO REMAIN OFF, INSTALL SAFETY TRAFFIC CONES AROUND THE OPENING. Monitor the fluid level on an hourly basis.
· Don’t allow high flows to the “new” clarifier to rob flow from any clarifiers that are already in service as this could upset downstream processes. If flows are too high, reduce influent to the “new” clarifier by partially closing the gate valve.
· Monitor overall plant flows and processes. Increase influent to the “new” clarifier if other processes are not impacted.
· If flow into the clarifier causes the flight and/or flight chain to move, reduce flow into the clarifier by partially closing the gate valve.
When the clarifier is slightly above half full, go to step 2 and start the sludge collection unit drive.
2. Put Sludge Collection Unit Drive Into Service:
a. If the single drive unit clarifier #1 {tag no. 1101MTR1721} is being put into service, go to Step 2.d.
b. If both clarifiers dual drive unit #2/#3 or unit #4/#5 5 {tag nos. 1101MTR1722 & 1101MTR1723} are being put into service, go to Step 2.e.
c. If the clarifier being put into service is on a dual drive and the other clarifier is to remain out of service, go to Step 2.f. For example, if #2 is being put into service but #3 remains out of service, go to Step 2.f.
d. Turn the local control switch to the AUTO position. Go to Step 3.
e. Turn the local control switch to the AUTO position. Both units will start. Go to Step 3.
f. Turn the local control switch to OFF position and then to the Forward position. Press the jog switch button. Slide the coupling until the drive sprocket is fully engaged (the coupling on the other unit should remain dis-engaged). Turn the local control switch to AUTO position and then to the Forward position.
g. Continue to monitor levels in the clarifier. When the clarifier is full, go to step 3 and start the Primary Sludge Cycle.
Step 3 takes place “downstairs” at Gallery #2.
3. Start Primary Sludge Cycle:
a. Turn the local actuated Rotork Primary Sludge Valve {tag nos. 1102OPS1677, 1102OPS1677A, 1102OPS1677B, 1102OPS1677C, 1102OPS1677D, 1102OPS167E7, 1102OPS1677F, 1102OPS1677G, 1102OPS1677H, 1102OPS1677I} switch to the OPEN position.
b. Manually close the two drain valves {tag nos. 1102VLV1679, 1102VLV1679A, 1102VLV1679B, 1102VLV1679C, 1102VLV1679D, 1102VLV1679E, 1102VLV1679F, 1102VLV1679G, 1102VLV1679H, 1102VLV1679I} that are located below the actuated Rotork Primary Sludge Valve associated with the clarifier being put into service.
c. Go to a SCADA workstation and select “ON” for the actuated Primary Sludge Valves that are associated with the primary clarifier(s) that are in service.
d. When the clarifier is full, go to step 7 and put the scum collector into service.
Steps 4 – 5 take place “upstairs” at the Primary Clarifier Deck.
4. Put Scum Collector Into Service:
a. If the single drive unit for Clarifier #1 {tag no. 1101MTR1724} is being put into service, go to Step 4.d.
b. If both clarifiers on dual drive unit #2/#3 or #4/#5 5 {tag nos. 1101MTR1725 & 1101MTR1726} are being put into service, go to Step 4.e.
c. If the clarifier being put into service is on a dual drive and the other clarifier is to remain out of service, go to Step 4.f. For example, if #2 is being put into service but #3 remains out of service, go to Step 4.f.
d. Turn the local control switch to the AUTO position. Go to Step 5.
e. Turn the local control switch to the AUTO position. Both units will start. Go to Step 5.
f. Slide the coupling of the unit to be put into service along the shaft so the teeth are fully engaged (the coupling of the unit that is out of service should be separated). Turn the local control switch to the AUTO position.
5. Open Influent Gate Valves 100%:
a. When the clarifier is full, make sure the influent gate valves {tag nos. 1101VLV1181 & 1101VLV1181A, 1101VLV1182 & 1101VLV1182A, 1101VLV1183 & 1101VLV1183A, 1101VLV1184 & 1101VLV1184A, 1101VLV1185 & 1101VLV1185A} are completely open. Turn counter-clockwise until they stop – this could take up to 100 turns. If the gate valves are not 100% open after the clarifier is full, the clarifier could go septic.
Step 6 takes place in the Operator’s Office
6. Record Data to Operator’s Log Book: Record primary clarifier start up activities to the log book with other entries for the day. Include the following in the entry:
a. Operator(s) that performed the Primary Clarifier Start Up SOP.
b. Which primary clarifier was put into service and the approximate time that the process began.
c. Reason for inspection (routine maintenance, troubleshooting, etc.)
d. Reason for start up (routine maintenance or process control).
e. Duration of time it took to fill the clarifier.
f. Note the approximate time that the SOP was completed.
g. Note any unusual conditions with flows, levels, odors or other process issues.
h. Note any damage, wear, or required maintenance on equipment.
Data & Records Management, Calculations, Forms, Reports
Data & Records Management, Calculations, Forms, Reports:
- Update log book.
- Update maintenance records (if applicable).
- Report any maintenance or attention that is required.
Limits/Criteria for Data/Results
Limits/Criteria for Data/Results:
Consistent treatment results during and after clarifier startup.
Corrective Action Plan
Corrective Action Plan:
Floating Sludge
Possible Cause: Sludge decomposing in the clarifier and floating to the surface.
Prevention and Cure:
1. Replace or adjust flights;
2. Increase sludge removal from hoppers by decreasing rest time between sludge removal periods or withdraw sludge for longer periods of time.
Black and Odorous Contents
Possible Cause: Septic wastewater or high solids return from sludge handling equipment or digester recycled supernatant.
Prevention and Cure:
1. Correct flow obstructions in the collection system;
2. Modify, pre-treat, reduce, or eliminate organic wastewater, such as cannery, milk processing, brewery, tannery, and organic textile wastes;
3. Pre-Chlorinate in the sewer system or ahead of sedimentation tank to reduce decomposition of wastewater; this is particularly effective when time of travel in sewer is usually long or wastewater temperatures are high, or when certain industrial wastes are present;
4. Pre-aerate or increase aeration rate;
5. Improve flow of wastewater system to reduce accumulations of solids.
Excessive Sedimentation in Inlet Channels
Possible Cause: Velocity too low for cross-sectional area of channel at existing flow rates.
Prevention and Cure:
1. Reduce cross-sectional area.
2. Agitate with air, water, or other means to prevent deposits.
Broken Scraper Chains and Frequent Shear Pin Failure
Possible Cause: Excessive load on mechanical scraper.
Prevention and Cure:
1. Periodically empty tank and examine all metal parts for defects and wear, also examine concrete surfaces for defects causing excessive drag.
2. Replace defective and worn parts, chain links, wear shoes, broken or warped scrapers (flights).
3. Operate collector mechanism for longer period and or pump sludge more often.
4. Grit accumulation could be causing excessive drag, if suspected cause, adjust air rate to grit chamber (lower rate) to allow more grit removal.
Inconsistent Sludge Removal Pumping Rate
Possible Cause: High content of grit, or other heavy compacted material.
Prevention and Cure:
1. Reduce grit content by adjusting airflow rate to grit chamber.
2. Back flush clogged pipelines or hoppers.
3. Pump sludge more frequently.
Equipment
Equipment:
EQUIPMENT | TAG NUMBER |
Clarifier #1 & #2 Slide Gate | 1101VLV1181B |
Clarifier #2 & #3 Slide Gate | 1101VLV1182B |
Clarifier #3 & #4 Slide Gate | 1101VLV1183B |
Clarifier #4 & #5 Slide Gate | 1101VLV1184B |
Clarifier #5 & #2 Slide Gate | 1101VLV1185B |
Primary Clarifier #1 Channel Influent Valve South | 1101VLV1181 |
Primary Clarifier #1 Channel Influent Valve North | 1101VLV1181A |
Primary Clarifier #2 Channel Influent Valve South | 1101VLV1182 |
Primary Clarifier #2 Channel Influent Valve North | 1101VLV1182A |
Primary Clarifier #3 Channel Influent Valve South | 1101VLV1183 |
Primary Clarifier #3 Channel Influent Valve North | 1101VLV1183A |
Primary Clarifier #4 Channel Influent Valve South | 1101VLV1184 |
Primary Clarifier #4 Channel Influent Valve North | 1101VLV1184A |
Primary Clarifier #5 Channel Influent Valve South | 1101VLV1185 |
Primary Clarifier #5 Channel Influent Valve North | 1101VLV1185A |
Primary Clarifier Sludge Collector Drive #1 | 1101MTR1721 |
Primary Clarifier Sludge Collector Drive #2 & #3 | 1101MTR1722 |
Primary Clarifier Sludge Collector Drive #4 & #5 | 1101MTR1723 |
Primary Clarifier Scum Collector Drive #1 | 1101MTR1724 |
Primary Clarifier Scum Collector Drive #2 & #3 | 1101MTR1725 |
Primary Clarifier Scum Collector Drive #4 & #5 | 1101GBX1726 |
Clarifier #1 Actuated Valve – Sludge Transfer | 1102OPS1677 |
Clarifier #1 Actuated Valve – Sludge Transfer | 1102OPS1677A |
Clarifier #2 Actuated Valve – Sludge Transfer | 1102OPS1677B |
Clarifier #2 Actuated Valve – Sludge Transfer | 1102OPS1677C |
Clarifier #3 Actuated Valve – Sludge Transfer | 1102OPS1677D |
Clarifier #3 Actuated Valve – Sludge Transfer | 1102OPS1677E |
Clarifier #4 Actuated Valve – Sludge Transfer | 1102OPS1677F |
Clarifier #4 Actuated Valve – Sludge Transfer | 1102OPS1677G |
Clarifier #5 Actuated Valve – Sludge Transfer | 1102OPS1677H |
Clarifier #5 Actuated Valve – Sludge Transfer | 1102OPS1677I |
Clarifier #1 – South Drain Plug Valve | 1102VLV1679 |
Clarifier #1 – North Drain Plug Valve | 1102VLV1679A |
Clarifier #2 – South Drain Plug Valve | 1102VLV1679B |
Clarifier #2 – North Drain Plug Valve | 1102VLV1679C |
Clarifier #3 – South Drain Plug Valve | 1102VLV1679D |
Clarifier #3 – North Drain Plug Valve | 1102VLV1679E |
Clarifier #4 – South Drain Plug Valve | 1102VLV1679F |
Clarifier #4 – North Drain Plug Valve | 1102VLV1679G |
Clarifier #5 – South Drain Plug Valve | 1102VLV1679H |
Clarifier #5 – North Drain Plug Valve | 1102VLV1679I |
Primary Sludge Transfer Pump #1 | 1102PMP1100 |
Primary Sludge Transfer Pump #1 – Suction Transfer Valve | 1102VLV1100 |
Primary Sludge Transfer Pump #1 – Discharge Transfer Valve | 1102VLV1100A |
Primary Sludge Transfer Pump #1 – Suction Drain Valve | 1102VLV1679J |
Primary Sludge Transfer Pump #1 – Discharge Drain Valve | 1102VLV1100D |
Primary Sludge Transfer Pump #2 | 1102PMP1200 |
Primary Sludge Transfer Pump #2 – Suction Transfer Valve | 1102VLV1200 |
Primary Sludge Transfer Pump #2 – Discharge Transfer Valve | 1102VLV1200A |
Primary Sludge Transfer Pump #2 – Suction Drain Valve | 1102VLV1679K |
Primary Sludge Transfer Pump #2 – Discharge Drain Valve | 1102VLV1200D |