Tuke and Bell is one of the UK's leading manufacturers of sewage purification equipment with over 90 years experience in design and production.
Heavy investment in the most advanced technology and the latest computer aided design systems facilitate the production of the highest quality equipment. Through serving the needs of both the water industry and domestic customers to the highest possible standards, we have achieved approval of our Quality Management System to ISO 9001 for Process Engineering, Design, Manufacture, Installation and Servicing of Water Purification Equipment.
Tuke and Bell offer two arrangements for grit extraction in the treatment of sewage, namely a square tank Grit Detritor and a Vortex Grit Trap, each having an associated Classifier System.
The first stage of sewage purification consists of initial screening which removes large solids and floating objects.
The second stage consists of removing coarser grit and silt particles which could interfere with machinery and pumps used in subsequent treatment processes and thus reduce the efficiency of the whole treatment operation.
Influent first enters the collection tank through baffles to slow down the flow and assist grit settlement. The tank is capable of handling a wide range of flow variation.
A rotary scraping mechanism, driven from the centre of the tank, moves settled grit through a discharge point located at the side of the collection tank.
From here the grit is transported by a multiple-rake reciprocating mechanism, mounted within the Cleaning Channel, which is a narrow, continuously sloping ramp.
The reciprocating action moves the grit, up the ramp towards a discharge point above top water level. At this point the grit is free of water, which assists easy and efficient disposal, and free of organic matter caused by the washing action of the reciprocating rakes.
A pumping unit is located within the Organics Return Chamber which induces a current of liquid to flow from the collecting tank through the Cleaning Channel and back into the collecting tank.
Organic matter originally settled with the grit and freed during the washing process is diverted back to the sewage flow for further treatment.
The Tuke and Bell Grit Detritor and Classifier carries out this complete process within a compact area with the minimum amount of odour. The system can be located either above or below ground level. Other types of Classifiers can easily be made available as required.
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The Tuke and Bell Vortex Grit Trap works on the retention and constant velocity principle.
Paddles which rotate in the same direction as the sewage provide a constant velocity of flow. A ‘spiralling’ flow is created by the paddles to keep organic material in suspension. The grit and heavier solids settle.
In order to clean and remove the grit, pressurised water and compressed air is passed through pipework located within the centre of the tank. After cleaning, the grit is pumped by the air lift method and is usually discharged into a Screw Classifier System.
The Tuke and Bell Classifier is a complete, free-standing unit, ideal for effective separation of grit from organic and other matter. A weir allows the separated organics to return, whilst grit is conveyed via the screw to a discharge point for disposal. Other types of Classifiers can easily be made available as required.
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GRIT DETRITOR AND RAKE CLASSIFIER
Grit Particle | Machine | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| 0.212 or more ---------- 0.300 or more | Flow Rate (l/s) | 164 to 235 | 295 to 420 | 460 to 660 | 667 to 950 | 910 to 1300 | 1150 to 1690 | 1500 to 2140 | 1850 to 2640 | 2240 to 3200 | 2670 to 3870 |
VORTEX GRIT TRAP AND SCREW CLASSIFIER
Tank Diameter | 2 | 2.5 | 3 | 3.5 | 4.2 | 5 | 6 |
Flow Rate | 50 to 120 | 121 to 210 | 211 to 340 | 341 to 530 | 531 to 880 | 881 to 1420 | 1421 to 2280 |
Tuke and Bell reserve the right to modify the design or amend the dimensions in respect of any equipment described on this brochure.
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2000 Tuke and Bell Ltd. All rights reserved. Last Updated : 16 March 2004 |