The bell type grit chamber is composed of motor, reducer, impeller main shaft, rotary table blade, air lifting and air washing system, sand suction pipe, steel platform and body (generally concrete tank, which can be selected by the user). The diameter and height of rotary table blade are customized according to the user's tank.
When the desander of swirl grit chamber is running, the sand water mixture enters the bell grit chamber from the tangent direction, forming a swirl. Driven by the driving device, the impeller of the mixing mechanism operates to control the flow rate and flow pattern of the sewage entering the pool
Due to the upward inclination of impeller blade, when rotating, the sewage in the pool will be spirally accelerated to form a vortex flow pattern, which will generate attention force. At the same time, the sewage flow in the pool is separated from each other under the action of the impeller blade stirring shear force. Depending on the gravity of sand and the centrifugal force of swirl, the sand particles are spirally settled along the pool wall, and accumulate to the central sand hopper. After being lifted by air lift or pump, they are discharged out of the pool for further treatment. In this process, appropriate blade angle and linear velocity conditions make the sand in the sewage be scoured and maintain good settlement effect. However, the organics and substances with small weight originally adhered to the sand flow out of the whirling grit chamber together with the sewage and enter the subsequent process for continuous treatment. The sand and a small amount of sewage flow into the sand water separator outside the pool. After the sand is separated, it is discharged and the sewage is discharged Return to grid well.
Outline diagram:
Technical characteristics:
The desander of whirling grit chamber makes use of the double action of hydrocyclone and slight centrifugal force of impeller rotation to separate sediment from lighter suspended matter (organic matter), giving full play to the role of hydrocyclone, maintaining the characteristics of less land occupation, short treatment stay time, good grit settling effect, strong separation of sand and water, reliable sand removal (especially inorganic grit in sewage).
Other:
Generally, the whirling grit chamber is of concrete structure. If the problem of land occupation is considered in the design, it can be designed as a steel tank with compact structure and small land occupation area. The specific situation depends on the situation.
