How to solve the high turbidity of the effluent from the Lamella clarifier

The reasons for the high turbidity of the effluent from the Lamella clarifier may be as follows

First, the water distribution at the inlet is not uniform, near the inlet, the liquid movement appears serious turbulence or water speed, resulting in the local liquid flow speed at the inlet large so that the original sludge deposited on the inclined pipe again;

2. The phenomenon of "short flow" appears locally, which affects the stability of the floc and causes the floc already formed in the early stage to be easily re-broken into fine floc.

3. In order to distribute water evenly and open holes in a small range, the flow rate through the hole is often larger than that of the advection sedimentation tank, resulting in the secondary crushing of the alum formed in the early stage, and it is easy to flush the dead mud deposited at the bottom of the water distribution hole, resulting in an increase in the turbidity of the effluent.

Solution:

1. The inclined tube and the horizontal plane are placed at a 60° inclination Angle. A row of fins are drawn below each inclined tube, and the horizontal plane is still at a 60° inclination Angle. The added fins can significantly reduce the Reynolds number of water flow and significantly enhance the viscosity of water flow process, which is conducive to precipitation. Moreover, the deposition path of particulate matter is shortened, and the dense particles are conducive to precipitation.

Two, ensure the uniform water distribution, the perforated flower wall water distribution, water distribution area at the beginning of the horizontal flow rate should be controlled between 0.010 ~ 0.018m/s.

3. A flat-flow rectifying section is added in front of the Lamella clarifier so that the outflow from the weir does not immediately enter the inclined tube sedimentation tank, but first passes through the flat-flow rectifying section (accounts for 1/3 of the total length of the sedimentation tank). The increased advection section enhances the impact resistance of the sedimentation tank and further reduces the horizontal flow velocity, which can not only play the role of rectifying, but also reduce the rising flow velocity in the inclined tube sedimentation tank. Strong impact load resistance. At the same time, the diversion wall is added in the advection section and the inclined pipe section, which increases the upward velocity of the inclined pipe and enhances the precipitation efficiency.