10 Hydrogritter Start Up
The Grit Pumps and Hydrogritter operate independently of each other. During normal operation, influent (containing grit) is pumped by the Influent Pumps to the Influent Distribution Box/Grit Chamber. The Grit Chamber is equipped with four grit hoppers.
During normal operation, the Hyrogritter separates the grit from the liquid stream. Grit is directed to a storage bin and liquid is drained back to the Influent Pump Station.
During abnormal operation, the Hydrogritter is bypassed and grit is returned to the head of the Grit Chamber.
- Keep the Grit Storage Bin lid closed unless the contents are being raked.
- Verify there is available capacity in the Grit Storage Bin for additional grit production. This also keeps the chute from becoming blocked.
- Make sure the bypass valves are open when the Hydrogritter is being worked on. If the Hydrogritter will be offline for an extended period of time, consider also bypassing the entire Grit System.
- During normal operation, grit is transferred to the Hydrogritter. During abnormal conditions, the Hydrogritter is bypassed.
- If the forced air system is down, organic material may settle in the grit chamber.
Operator I, knowledge of grit system and equipment controls.
- Record activity to log book.
- Verify sufficient capacity in the Grit Storage Bin for additional grit production.
1. Hydrogritter Start Up {tag nos. 1004AUGR/MTR 0400}:
a. Open the hatch to the Grit Storage Bin and check the volume of collected grit.
b. Rake the collected grit. This increases the storage volume of the storage bin and keeps the chute from becoming blocked.
c. Close the lid to the Grit Storage Bin before starting up the Hydrogritter.
d. Check Odor Control Unit.
e. Locate the Hydrogritter ON/OFF Switch and turn the switch to ON.
f. Verify that forced air is fed to the diffusers {tag nos. 1004DIF0231 & 1004DIF0231A}. The forced air keeps organic material suspended for further treatment while allowing grit to settle into the chamber.
2. Hydrogritter Shutdown {tag nos. 1004AUGR/MTR 0400}: During a normal Hydrogritter Shutdown period, the Grit Pumps continue to operate. Grit is discharged to the head of the Grit Chamber by the Grit Pumps and grit is drawn from the downstream end of the Grit Chamber by the Grit Pumps.
a. Locate the Hydrogritter ON/OFF Switch and turn the switch to OFF.
b. Locate and open the Grit Bypass Valve {tag no. 1004VLV0676B}, which is located in the Grit Pump Room. This directs the grit back into the Grit Chamber, instead of to the Hydrogritter.
c. If the Hydrogritter is bypassed for an extended period of time, it may be necessary to also bypass the Grit Chamber and the entire Grit System. See the Extended Hydrogritter Bypass SOP for this procedure.
3. Extended Hydrogritter Bypass {tag nos. 1004AUGR/MTR 0400}: If the Hydrogritter is bypassed for an extended period of time, the grit hoppers may plug and it may be necessary to bypass the entire grit. This SOP should be performed after the Hydrogritter Shutdown SOP has been performed.
a. Locate the Bypass Channel Slide Gate {tag no. 1004VLV0679}. Remove the slide gate from the Bypass Channel {tag no. 1004VLV0679} and place the slide gate in the Grit Chamber Influent Channel {tag no. 1004VLV0679A} (The channels and gates can be accessed “upstairs” below the aluminum grating). All influent flow, including grit, is now directed to the Primary Clarifiers.
4. Observe Hydrogritter Operation:
a. Listen for excessive noise or vibration.
b. Check for oil or process fluid leaks.
5. Record Data to Operator’s Log Book: Record Hydrogritter Activities to the log book with other entries for the day. Include the following in the entry:
· Operator(s) that performed the Hydrogritter Start Up SOP.
· Note condition of equipment, piping, valves, etc.
· Note any unusual conditions with flows, levels, odors or other process issues.
· Note any damage, wear, or required maintenance on equipment.
- Update log book.
- Update maintenance records (if applicable).
- Report any maintenance or attention that is required.
Grit is removed from the liquid stream and transferred to a storage bin.
If the flowmeter displays flows below 140 gpm one of the grit hoppers probably has an obstruction. Click here for the Grit Obstruction SOP.
EQUIPMENT NAME | TAG NUMBER |
Hydrogritter, Auger | 1004AUGR0400 |
Hydrogritter, Auger Motor | 1004MTR0400 |
Hydrogritter Switch | 1004HYS0400 |
Hydrogritter Isolation Valve | 1004VLV0676A |
Hydrogritter Bypass Isolation Valve | 1004VLV0676B |
Diffusers | 1004DIR0231 & 1004DIF0231A |
Grit Bypass Valve | 1004VLV0676B |
Stop Gate, Inlet Bypass Channel | 1004VLV0679 |
Stop Gate, Outlet Bypass Channel | 1004VLV0679A |