General knowledge and design improvement of rotary Decanter

1. Rotary Decanter

According to its structure, decanter can be divided into rotary type, siphon type, self floating type, simple type and so on. At present, most of them are rotary type. It consists of decanting weir, branch pipe, main pipe, rotary support, sliding support, driving device, automatic control device, etc. Working under the action of the driving device.

The middle line of rotary support at the bottom of the decanter at the decanter weir mouth moves axially downward in a variable speed circle. In this process, the supernatant in the SBR reaction tank will flow into the decanter branch pipe through the decanter weir mouth and be discharged through the decanter main pipe. After the water decanting work is completed, the water decanting weir mouth moves upward at a constant speed with the middle line of the rotary support at the bottom as the axis, so that the water decanting weir mouth stops in standby mode, and the next water decanting process can be carried out after the completion of water inlet, sedimentation and other processes.

2. Design key:

When the driving device drives its weir to descend at a constant speed, its weir running track is circular motion. With the change of angle in the descending process, its peripheral tangent velocity μ is uniform, while the horizontal running velocity μ 1 and vertical descending velocity μ 2 are a group of variables, and the closer to the horizontal position, the fuller μ 1 is, the faster μ 2 is.

Because the closer the Zui low water level of the decanting water is, the closer it is to the mud area at the bottom of the tank. Therefore, according to the process design, the decanting speed should be slow. Otherwise, the sludge at the bottom of the tank will be turned over and discharged together with the supernatant, causing serious damage to the water quality of the effluent. Therefore, it is very important to make μ 2 constant.

According to the process requirements, during the water decanting process, the weir mouth is always in the horizontal position to ensure the uniform water decanting according to the set weir load. However, due to its manufacturing process and installation characteristics, it is difficult to guarantee and adjust the horizontal position of the weir mouth. In order to solve this problem, on the basis of summing up the past experience of design, manufacture, installation and actual operation, a simple adjustable weir device is added, which has achieved good effect in actual operation.

3. Design improvement

The original driving device uses the combination of four-wheel slideway and helical gear to complete the decanting process, which is complex in structure and inconvenient in installation. Moreover, due to the exposed part of the slideway, the problem of anti-corrosion is relatively serious. Now, this kind of electric push rod can be used to change this phenomenon.

The electric push rod is composed of driving motor, coupling, worm wheel, worm, reduction gear, screw rod, copper nut, guide sleeve, push rod, sliding seat, shell, internal adjusting travel switch and other parts, with compact structure, flexible action, stable and convenient installation.

After the motor is decelerated by the speed change mechanism, a pair of screw nuts are driven to change the rotation motion of the motor into a linear motion. The push-pull action is completed by the motor's reverse rotation, and the thrust is equal to the pull force. For example, the complex motion such as rotation and shaking can be completed by various levers, rocker arms or connecting rods.