Working principle of decanter

1. Each set of rotary decanter of slaughterhouse sewage treatment equipment includes movable weir, scum retaining device, drainage branch pipe, rotary main outlet pipe, drive device, support, vent pipe, "O" ring, flange, lead screw, limit switch, probe, helical gear reducer motor, fasteners required for installation, frequency converter, local control box, etc.

2. Decanter is the key mechanical equipment commonly used in CASS and cast sewage treatment process. It can automatically rise and fall with the change of water level in the drainage stage, and discharge the treated supernatant from the surface of the reaction tank, while the scum on the surface is retained in the reaction tank.

3. The decanter of slaughterhouse sewage treatment equipment is fully automatic controlled and operated intermittently.

4. In the stage of aeration and sedimentation, the water decanter is located above the water level. At the beginning of the water decanting stage, the driving mechanism drives the screw rod of the increasing mechanism, and makes a straight-line downward movement to drive the four-bar linkage of the hinge to swing, making the outlet weir close to the water surface. At this time, the pontoon enters into the water surface. Due to the buoyancy, the scum around the outlet weir is pushed away from the water surface at the same time. In addition, the Scum Baffles on both sides of the pontoon form a scum free outlet area. The distance between the pontoon floating on the water surface and the weir mouth can be adjusted automatically.

When the outlet weir gate reaches the water surface, the supernatant slowly enters the weir mouth from the bottom of the pontoon. In the process of drainage, frequency conversion is used to keep the water output uniform without disturbing the supernatant, so as to ensure the process requirements. When the outlet weir reaches the set water level, it will automatically return to the initial position. It can realize automatic speed change in the working process, the return speed of decanting water is 2-3 times of the falling speed, it can be confirmed that the water flow into the outlet weir is laminar, and the falling speed keeps the water output constant.

5. Within the time set by PLC, the outlet weir will be lowered to 30 ~ 50mm below the water surface by motor, reducer and screw elevator. According to the level switch signal, the frequency conversion speed control decanting will be started to make the decanting water tank drop and recover at the same speed, so that the liquid level under the weir mouth will not stir and the drainage will be balanced.

6. When slaughtering sewage treatment equipment is under the action of water buoyancy, the scum retaining mechanism of the pontoon pushes away the scum and blocks it, so that the supernatant enters the weir tank and begins to decant, and is discharged out of the tank through the horizontal rotary drain pipe, the tank surface drops until the decanting stops at the set water level, the inverter automatically switches to the power frequency form, and the push rod restores the whole weir tank to the original position. It can make the water level change constantly and can automatically carry out periodic drainage. Under the rated working conditions, the actual decanting capacity shall not be less than 1.05 times of the designed decanting capacity.