Turbid circulating water concentration dehydrolyzing method

Abstract

The invention discloses a method of concentrating and dewatering turbid circulating water, which comprises steps of firstly pouring whole sludge discharged by a settling filtering device during two continuous sludge discharging periods into two concentration tanks, resting the sludge in the concentration tanks and settling for 4-48 hours, employing a water discharge pump to pump clear water on the upper layer inside the concentration tank to the settling filtering device for performing reprocessing, employing a mud scraper to stir and scrape the a sludge layer at the bottom of the concentration tank, and employing a sludge pump to pump the sludge after being stirred inside the concentration tank to a plate and frame filter press for performing dewatering. The method not only simplifies the process flow of processing the turbid circulating water with convenient operation and saved investment, but also increases the dewatering efficiency of the plate and frame filter press.

Description

technical field [0001] The invention relates to a sewage treatment method, in particular to a concentration and dehydration method for treating turbid ring water discharged from a rolling mill. Background technique [0002] The turbid ring water produced in the steel rolling mill is mainly the direct spray cooling water of the rolling line equipment. The returned water after use contains a large amount of impurities such as scale and oil. A sludge regulating tank is set behind the tank to form a sludge regulating tank treatment process. The process is: chemical degreaser sludge discharge—sludge regulating tank (for regulation and homogenization)—slurry pump (for pressurization)— Plate and frame filter press (sludge dewatering). Among them, the function of the sludge regulating tank is: after storage and adjustment, the bottom sludge of the chemical degreasing settler that is discharged intermittently and in a short period of time with a large flow rate is homogenized into c...

AI Technical Summary

Problems solved by technology

Among them, the function of the sludge regulating tank is: after storage and adjustment, the bottom sludge of the chemical degreasing settler that is discharged intermittently and in a short period of time with a large flow rate is homogenized into continuous and low-flow slurry, and sent to the plate and frame filter press for dehydration , The defects of the treatment process of the sludge regulating tank are as follows: 1. The sludge regulating tank is limited by the depth of the pool, the plane area is relatively large, and the particle density of the oxidized iron scale sludge is high. The thick sludge layer accumulates and settles, and it is often necessary to stop the tank to clear the sludge, which increases the labor intensity of the workers and affects production; 2. Due to the lack of sludge concentration function and the high density of iron oxide sludge particles, the adjustment tank Sludge stratification is obvious. If the sewage with low sludge concentration in the shallow layer of the tank is first extracted during production and sent to the plate and frame filter press for dehydration, problems such as thin filter cake, long filtration cycle, and low filtration efficiency will occur; The sludge with a high concentration of deep sludge in the pool is sent to the plate and frame filter press for dehydration. Although the filter cake is thick and the filtration cycle is short, due to the large amount of shallow sewage in the pool, it is still impossible to discharge the sludge from the chemical degreaser. All the sewage and sludge discharged in the cycle are filtered, which affects the normal sludge discharge of the degreaser in the next cycle, and also causes the sludge dehydration efficiency of the plate and frame filter press to be low in the subsequent dehydration step

[0004] At present, most of the transformation of the old system and the design of the new system adopt the intermediate link of adding a thickening tank. Although the defects of the sludge regulating tank treatment process have been overcome, the dynamic continuous sludge thickening process has the following defects: 1. Due to the sewage entering the dynamic thickening tank It is difficult to adjust the flow rate and working time between water and bottom sludge discharge to a suitable working state, which makes it difficult to increase the concentration of sludge in the thickening tank, and the dehydration efficiency of the plate and frame filter press is still low; 2. The investment is high and the link Many, inconvenient to operate

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