purpose
The sand removal machine is mainly used in the cyclone sedimentation tank of urban sewage treatment plants. This equipment utilizes hydraulic cyclone to effectively separate sand and organic matter, making it an ideal sand removal equipment.
Structure and working principle
The swirling sand settling tank adopts a conical bottom circular tank, which is equipped with a paddle separator. After the sewage enters from the tangential direction of the tank and rotates 270 ° (clockwise when viewed from above), it is discharged from the discharge channel. Using a certain flow rate of the inlet water as the power, it moves tangentially along the inner wall of the circular sand settling tank to form a swirling flow. At the same time, it is stirred by paddle blades to make the liquid swirl and axial vortex, thereby accelerating the sedimentation of sand particles in the sewage, Effectively separating organic matter and sand particles in the water, while also utilizing the principle that the smaller the water flow section near the center, the faster the water flow speed, and the increasing water flow speed towards the center at the bottom, the settling sand at the bottom of the pool moves in a spiral trajectory towards the center sand bucket. The organic matter rises upwards in the center of the pool and is discharged along with the effluent flow. The bottom sediment is lifted by the lifting device and enters the sand water separator for sand water separation. After that, the sewage is returned to the grid well.
Technical parameters and installation dimension table

The operating program stirring solenoid valve is a normally open valve, that is, air stirring is the basic continuous operation of the operating cycle should be determined according to the sand content in the water, the device program
is tentatively set to 90-210min (adjustable), before the need to discharge sand, first open the air flushing solenoid valve and then close the stirring air solenoid valve, the sand and gravel precipitated in the sand storage hopper are loosely ventilated, the time is 1-2min (adjustable): then open the air stripping solenoid valve, close the air flush solenoid valve, and lift the sand and gravel in the sand storage hopper to the separator, At the same time, the screw conveyor is turned on with a delay of 15sec, and the sand and gravel in the sand water separator are lifted to the sand truck (bucket) for a time of 10-30min (adjustable). After the sand lifting operation is completed, the air stirring grit is started, and the operation is repeated to achieve the purpose of separating the sand and gravel in the water.
The number of times you turn on the air lift pump per day depends on the amount of sand in the water and the amount of water treated, and is generally about 6-12 times.

Automatic control The control system of this device is composed of a PLC (programmable controller) as the core, the centralized control system is supplemented, and the control cabinet is composed of an industrial PLC controller, the main console and the driving device, which can run automatically according to the pre-set program, and can also be run according to the process requirements through the main console switch button to issue various control
instructions.

Operation and operation This device can be divided into two forms: automatic control operation and manual operation
, and the operating cycle is 120'-240'. The process principle and operation control are shown in the figure below.

Working principle diagram
Note: DZ1-Air stripping solenoid valve (normally closed) DZ2-Air flushing solenoid valve (normally closed) DZ3 air stirring solenoid valve (normally open) M1 screw separator