Grit Removal  

Types :

• Detritus.
• Constant velocity channels (Moving trolley type).

Detritus :

Consists of square tank, velocity control is done with the help of fins (RCC or FRP), simple mechanism consists of drive unit, drive shaft, scraper frame 2 or 3 depending on tank size ,scrapers pushing the grit to a corner of the tank.

Moving trolley type

Consists of reciprocating bridge, trolley, scrapers and skimmers, electrical panel, limit switches, beach plate and other accessories. Scraper scraps the floor in the forward motion , lifts during backward motion, Skimmer skims the surface in the backward motion , lifts during forward motion. Grit pumps can also be used for collecting the settled grit.

Latest trends :

• Use of diffused air in the grit chamber (aerated grit chamber) helps effective separation of organic matter from grit. Fine bubble diffusers are used.
• Dedicated control panel for grit should be a prerequisite to effectively control the functioning of the equipment by PLC control.
• MOC − Aluminium alloy bridge − light weight, long life, scraper / skimmer − MS / SS 304, 316.

Grit washing mechanism :

• Screw conveyor inclined at less than 30º.
• Reciprocating classifier.