JPS632641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sieve drum suitable for dewatering sludge collected from a sewage treatment plant.

Conventionally, sludge collected from sewage treatment plants has a high water content and cannot be dumped, landfilled, or fermented as it is, so it is dehydrated. However, this dewatering method involves adding a flocculant to the collected sludge with a high water content, feeding it into a coagulation mixing tank, then feeding it to a belt press type dehydrator, performing the desired dehydration, and then dewatering the sludge. The cake is sent to the next process, and the wastewater discharged from the dehydrator is once led to the settling tank.
The supernatant water with precipitated sludge particles is used as washing water for the dehydrator. However, in this method, the sludge is flocculated with a flocculant and then directly supplied to the dehydrator together with the dehydrated water for dewatering, resulting in poor dewatering efficiency and poor reuse efficiency of the desorbed water as washing water.

In view of this, the present invention proposes a sieve drum for sludge treatment that improves dewatering efficiency while efficiently reusing desorbed water. Next, the present invention will be explained in detail with reference to the illustrated embodiment. .

In the figure, 1 is the main body of a sieve drum for processing sludge collected from sewage treatment plants, etc. The sludge is supplied into the sieve drum through a sludge supply pipe 2 using an appropriate transfer means. Bulky waste and the like are removed in advance, and a flocculating liquid is supplied from a flocculating liquid tank stored in the tank, and the sludge and flocculating liquid are mixed in advance with a static mixer or the like. As shown in detail in the drawing, this sieve drum 1 for sludge treatment is oriented horizontally and supported rotatably by rollers 3 etc., and its interior is divided into a front stage 1A and a rear stage 1B. A flocculation mixing tank 4 is provided. A stirring blade 5 is provided in this flocculation mixing tank, and sludge mixed with a flocculant in advance or both sludge and flocculant are supplied into the tank 4 from the sludge supply pipe 2, and when the sieve drum rotates. The aggregation mixing tank integrated with the drum also rotates, so that the desired mixing and agitation is performed by the blades 5. Also, treated water, such as dehydrated water from a dehydrator, is supplied to the outer circumference of the flocculation mixing tank 4 via the water supply pipe 6 and the treated water receiving portion 1c, and is passed around the front and rear outer circumferences of the sheave drum.

This treated water receiving section 1c is attached to the sludge supply side of the front stage 1A, receives treated water from the water supply pipe 6, and supplies the treated water to the coagulation-mixing concentration tank 4.
Further, a blade 7 is provided in the rear end of the sheave drum,
The sludge sufficiently mixed with the flocculant is supplied to the front stage, where it is further mixed and stirred and primary dewatering is performed. The sludge after dewatering is sequentially discharged from the opening end of the sieve drum, and the desorbed water falls from the front and rear stages of the sieve drum into a water collection chute 8 provided below the sieve drum and is discharged. sheave drum 1
The outer circumferential surface of the sheave drum is washed with washing water jetted from a washing nozzle 9 arranged above the sheave drum.

The sludge collected from sewage treatment plants, etc. is mixed with flocculating liquid in advance and supplied to the flocculation mixing tank installed in the sieve drum, and inside the sieve drum, a dewatering machine is installed inside the outer periphery of this flocculation mixing tank. The treated water is supplied from desorbed water and other sources.

After the treated water is once received in the treated water receiving section, it is supplied into the sieve drum and thoroughly filtered. A large number of flocculants and sludge flocs are present in treated water, mainly sludge desorbed water. However, the binding force of the flocs is weak, so if treated water is supplied directly to the sieve drum, the flocs will break and pass through the sieve drum. The treated water receiving section adjusts the flow of treated water and supplies the treated water to the sieve drum surface from the side.

The sludge is coagulated in the rotating tank 4, and the solids in the waste water are filtered and removed by the sieve drum, and the desorbed water is drained from the sieve drum to separate the solids and water, and the sieve drum is cleared from clogging. Cleaning water is sprayed from the cleaning nozzle from above the outer periphery to prevent this. The solid content of the sludge separated in this sieve drum is sent to the next process, a dehydrator.
The water is further dehydrated to the desired moisture content and sent to the next process as a dehydrated cake for treatment.The dehydrated water separated from the sieve drum is temporarily stored in a tank and pumped to the sieve drum cleaning nozzle and dehydrator. It is supplied to the fabric washing nozzle and used as washing water. In addition, dehydrated water dehydrated using a dehydrator or the like is also supplied into the sieve drum by a pump. In addition, wastewater from a dehydrator or the like may be directly supplied into a gutter provided in the sieve drum.

According to the present invention, the sieve drum is divided into front and rear parts, and a flocculating mixing tank is provided in the front part, so that the flocculant is mixed with the sludge and supplied, and the sludge is sufficiently mixed and stirred in this tank, flocculated, and then mixed. The treated water supplied through the treated water receiving part to the sieve drum provided on the outer periphery of the tank is sufficiently overtreated, the two streams mentioned above are simultaneously treated in one batch, and the sieve drum has a simple structure. It has advantages such as being able to be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is an external view, and FIG. 2 is a sectional view. 1...Sieve drum, 2...Sludge supply pipe, 3...
...roller, 4...coagulation mixing tank, 5...blade, 6...
Water supply pipe, 7... impeller, 8... water collection chute, 9...
...Cleaning nozzle.

Claims (1)

[Claims] 1. A coagulation-mixing tank equipped with stirring blades on the inner circumferential surface for mixing supplied sludge, a rotatable sieve drum for passing treated water such as desorbed water of sludge on the outer periphery of the coagulation-mixing tank, and A sieve drum for sludge treatment, characterized in that it is integrally provided with a treated water receiving section adjacent thereto which receives the treated water supplied from the outside and then supplies it to the sieve drum.