Municipal sewage desanding device and desanding method

Abstract

The invention discloses a municipal sewage desanding device and a desanding method. The device comprises a water collecting unit, a sand removing unit, a water storing and returning unit and a sand collecting unit, wherein the water collecting unit internally comprises the sand removing unit which is alternately connected in a circulating static and dynamic manner; a water inlet is formed in the upper left portion of the water collecting unit. A spiral stirrer is arranged in the sand removing unit; the lower part of the water collecting unit is connected with the water storing and returning unit through a water outlet pipe; the lower part of the sand removing unit is connected with the water storing and returning unit through a water return pipe; the lower portion of the sand removing unitis connected with the sand collecting unit through a sand conveying pipe. A one-way water valve is arranged in the water storing and returning unit; the lower part of the water storing and returningunit is provided with a water outlet, and the right side wall of the san collecting unit is provided with a sand outlet. The device is high in automation degree, a large amount of labor work is reduced and avoided, the labor cost is reduced, the precision is high, the sewage treatment efficiency is improved, and the service lifetime of subsequent water treatment equipment is prolonged.

Description

technical field [0001] The invention relates to the technical field of sand removal for sewage, in particular to an urban sewage sand removal device and a sand discharge method. Background technique [0002] The amount of sand settling in general urban sewage can be calculated as 1 million m3 of sewage sand settling 30m3, with a water content of 60% and a density of 1500kg / m3, but some sewage treatment plant inlet water samples are often higher than the above values, or even 2-3 times the designed sand content. The increase of the sand content in the sewage will affect the various processes in the operation, which is very unfavorable to the daily operation of the sewage treatment system. [0003] Inlet pump house forebay is the catchment area of ​​the pump house and also becomes a grit chamber for coarse particles in the sewage. In the water inlet channel, there is more serious sand accumulation in the diffusion and dead corners, which makes the water intake of the pump bl...

AI Technical Summary

Problems solved by technology

Such a short residence time causes a lot of fine sand to enter the primary settling tank with the effluent of the grit chamber, which aggravates the wear and tear of the mud discharge equipment of the primary settling tank

In the sludge treatment system, due to the fluidity and easy deposition of sand particles, it will cause blockage of the sludge pipeline and sand accumulation at the bottom of the digester, thus affecting the normal operation of the digester and biogas production

The existence of sand in the sewage treatment operation system and the failure to deal with it in time have become one of the important reasons for the high cost of sewage treatment and serious equipment loss. Therefore, it is imminent to invent an efficient and comprehensive sewage sand removal device.

[0004] Patent CN208577518U describes a sewage desanding device provided with a sedimentation tank and a sand lifter. The sand lifter is arranged inside the stirring shaft of the sedimentation tank, and the sand suction port of the bottom sand lifter pipe goes straight to the bottom of the sedimentation tank to remove the deposited silt. Discharge, the device can perform primary filtration and control the discharge of clean water before desandering of sewage, avoiding the clogging of the desander, and ensuring the stable desandering; the desandering effect cannot be guaranteed. Patent CN208542692U describes a backwash cyclone The sander sewage sand removal device, the outlet of the backwash pump is connected to two pipelines, one is connected to the backwash pipe, and the other is connected to the cyclone desander, this operation makes the sludge tank discharge the sand more thoroughly, the sand removal efficiency is low, and the degree of automation Low

Images