CN204384990U - A kind of recirculated cooling water lime soften for sewage clarification filtration treatment system - Google Patents

Abstract

The utility model relates to a water treatment system, in particular to a circulation cooling water lime softening clarification and filtration treatment system suitable for electric power, petrochemical, metallurgy and other industrial sectors. It mainly solves the technical problems existing in the prior art, such as large occupied area, large sludge discharge, and low filtration efficiency. The utility model comprises a high-density sedimentation tank (1) that can be fed into circulating cooling water. The high-density sedimentation tank (1) is connected with a mixing tank (2) through a pipeline, and the mixing tank is connected with a variable pore filter through a pipeline. The pool (3) and the variable pore filter are connected to a clear water pool (4) through pipelines, and the clear water pool is connected to a circulating cooling water pool.

Description

A circulating cooling water lime softening clarification filtration treatment system

technical field

The utility model relates to a water treatment system, in particular to a circulation cooling water lime softening clarification and filtration treatment system suitable for electric power, petrochemical, metallurgy and other industrial sectors.

Background technique

With the increasing shortage of surface water resources and the increasingly severe pollution, the development of industrial enterprises is increasingly restricted by water resources. Circulating cooling water consumes a lot of water, and the amount of sewage is also large. Softening the circulating cooling water, increasing the concentration ratio of the circulating cooling water, reducing the amount of circulating sewage and reducing pollutant discharge have broad application prospects. However, to increase the concentration ratio of circulating cooling water, it is necessary to remove the temporary hardness and alkalinity in circulating cooling water.

A Chinese patent discloses a lime softening, clarification, and filtration water treatment device (publication number: CN200820143211.0), which mainly uses clarification and filtration processes as an advanced treatment process for effluent from municipal sewage treatment plants to remove temporary hardness, turbidity, etc. Indicator, as make-up water for recirculating cooling system. In this method, the clarifier has a large amount of sewage discharge, the clarifier occupies a large area, and has a large sewage discharge. If no disinfectant is added to the clarifier, it is easy to breed algae and affect the water quality of the effluent; the filter material in the filter is quartz sand. The fine filter material caused by hydraulic sieving is concentrated on the surface of the filter layer, which affects the filtration efficiency, the quality of the effluent is unstable, and the amount of backwash water is large.

Utility model content

The utility model provides a circulating cooling water lime softening, clarification and filtration treatment system, which mainly solves the technical problems of the prior art, such as large floor area, large sludge discharge, and low filtration efficiency.

The above-mentioned technical problems of the utility model are mainly solved by the following technical solutions:

A circulating cooling water lime softening, clarifying and filtering treatment system of the present invention includes a high-density sedimentation tank that can be fed into the circulating cooling water. The high-density sedimentation tank is connected with a mixing tank through a pipeline, and the mixing tank is connected through a pipeline. There is a variable pore filter, and the variable pore filter is connected to a clear water pool through pipelines, and the clear water pool is connected to a circulating cooling water pool.

The circulating cooling water is transported to the high-density sedimentation tank. The high-density sedimentation tank has characteristics: the high-density sedimentation tank has a reaction zone and a sedimentation zone. The reaction zone is divided into two parts: the fast coagulation stirring reaction zone and the slow coagulation plug-flow reaction zone. The raw water is introduced into the center of the bottom plate of the rapid coagulation stirring reaction tank, and the water flow in the reaction zone is uniformly mixed through the impeller, and the concentration of suspended flocculent or crystalline solid particles in the reaction zone is kept at an optimal state, and the concentrated sewage from the sedimentation zone is passed The sludge external recirculation system ensures the sludge concentration in the pool. The role of the slow coagulation plug-flow reaction zone is to continuously increase the size of the alum flower particles. The alum flowers enter the sedimentation zone at a slow speed, which can avoid damage to the alum flowers or generate vortices, and ensure that a large amount of suspended solid particles are evenly deposited in the sedimentation zone. The alum flower collects into sludge in the lower part of the sedimentation area and concentrates it. Part of the concentrated sludge is circulated to the entrance of the reaction area through the sludge return pump, and the remaining sludge is transported to the slurry tank of the desulfurization system through the sludge transfer pump. The concentration of the thickened sludge is at least 20 g/l. The settling area is equipped with a counter-current inclined pipe to settle the remaining alum flowers, and the effluent flows to the mixing tank by itself through the overflow weir. The temporary hardness of the effluent from the high-density sedimentation tank is ≤1mmol/L. It has the characteristics of stable and reliable operation, small footprint, compact layout, and saving the amount of chemicals.

The circulating cooling water after adding acid flows into the variable pore filter by itself. The variable pore filter has the characteristics: during the filtration process, the suspended particles flocculate in the same direction in the pores of the filter layer, so that the small particle suspension becomes large particle suspension The material is intercepted by the filter material, which improves the filtration efficiency. The filter material of the variable pore filter is evenly filled with coarse filter material (1.2-2.8mm) and fine filter material (0.5-1.0mm). The coarse filter material relies on the entire filter layer to filter, avoiding the surface filtration of the filter layer formed by ordinary filters, reducing the resistance of the filter layer, avoiding premature penetration of suspended particles, and increasing the filtration rate. The addition of fine filter material and mixing in the filter layer greatly reduces the local porosity of the coarse filter material, improves the flocculation of fine particles in the circulating water, is more conducive to the removal of fine particles, and greatly improves the filtration efficiency. Pollution interception capacity. The turbidity of the variable pore filter effluent is ≤3NTU. It has the characteristics of high filtration rate, large sewage interception capacity, long operation period, increased water production, stable and simple operation, good effluent water quality, good backwashing effect, and low backwashing water consumption.

The sedimentation area of the high-density sedimentation tank adopts a central hanging sludge scraper to collect the sludge in the sedimentation area to the central sludge hopper, and return part of the sludge to the reaction area, and the remaining sludge is transported to the slurry tank of the desulfurization system. The reaction area adopts the combination of fast coagulation stirring reaction tank and slow coagulation plug-flow reaction tank. The pH value in the tank is adjusted to about 10, so that Ca ²⁺ and Mg ²⁺ are separated by CaCO ₃ and Mg(OH) ₂ The form is precipitated from the water to realize the softening treatment of the circulating water.

The variable pore filter is designed to distribute water evenly (to ensure a certain liquid level above the filter material). In order to better ensure the treatment effect, the water distribution and air intake method is designed as a branch pipe, and the backwash adopts water washing-air-water mixed scrubbing- The way of washing. The variable pore filter valves all adopt automatic valves to realize automatic control.

On-line monitoring devices that can monitor indicators such as turbidity, conductivity, temperature, flow, pH value, and sludge level are installed in high-density sedimentation tanks, mixing tanks, and variable pore filters.

As a preference, part of the sludge at the bottom of the high-density sedimentation tank is returned to the reaction zone of the high-density sedimentation tank through the sludge return pump, and the remaining sludge is sent to the lime slurry tank of the desulfurization system by the sludge transport pump.

As a preference, the variable pore filter can realize water washing and air-water mixed scrubbing of the filter material of the variable pore filter by setting a backwash water pump and a backwash fan. The pump delivers to the inlet pipe of the high-density sedimentation tank.

As a preference, a stirrer is provided in the front-end reaction zone of the high-density sedimentation tank to realize sufficient mixing of circulating water and chemicals, and a sludge scraper is installed in the sedimentation zone of the high-density sedimentation tank to concentrate the sludge into the mud hopper area, and the sludge returns and The transmission adopts electric valves to realize fully automatic control.

Preferably, each valve of the variable pore filter uses an electric valve. The variable pore filter adopts rare earth porcelain sand filter material, the particle size of the main filter material is 1.2-2.8mm, and the particle size of the auxiliary filter material is 0.5-1.0mm. The valves adopt electric valves to realize automatic control.

Preferably, the coagulation area and the flocculation area of the high-density sedimentation tank are connected with a dosing system, and the dosing system includes a lime milk dosing device, a coagulant dosing device, a disinfectant dosing device, and a flocculant dosing device. The lime milk uses quicklime with an effective content of 80%, the coagulant aid uses 0.1-0.3% polyacrylamide solution, the fungicide uses 10% sodium hypochlorite solution, and the flocculant uses 10% polyferric sulfate liquid.

Preferably, the mixing tank is connected with a sulfuric acid dosing device through a dosing pipe. Sulfuric acid adopts 98% concentrated sulfuric acid liquid.

Therefore, the utility model adopts physical and chemical methods to make the circulating cooling water have high removal rate of hardness, turbidity and alkalinity, small floor area, less sludge discharge, high processing efficiency, low operating cost, fully automatic The operation meets the water quality requirements of the treated cooling water in the circulating cooling system, improves the concentration ratio of the circulating cooling water system, and the system structure is economical and reasonable.

Description of drawings

Accompanying drawing 1 is a kind of structural representation of the utility model.

Parts, parts and numbers in the figure: high-density sedimentation tank 1, variable pore filter tank 2, mixing tank 3, clear water tank 4, backwash drainage tank 5, sludge return pump 6, sludge delivery pump 7, backwash water pump 8. Backwash drainage pump 9, backwash fan 10, lime milk dosing device 11, coagulant aid dosing device 12, disinfectant dosing device 13, flocculant dosing device 14, sulfuric acid dosing device 15, agitator 16. Mud scraper 17.

Detailed ways

The technical solutions of the present utility model will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Embodiment: A circulating cooling water lime softening, clarifying and filtering treatment system of this example, as shown in Figure 1, includes a high-density sedimentation tank 1 where the circulating cooling water enters, the high-density sedimentation tank effluent to the mixing tank 2, and the mixing tank effluent to variable porosity Filter tank 3, its effluent flows to clear water pool 4 by itself, and overflows in the circulating cooling water pool. The sludge at the bottom of the high-density sedimentation tank returns part of the sludge to the reaction zone in the high-density sedimentation tank through the sludge return pump 6, and the remaining sludge is transported to the lime slurry tank of the desulfurization system through the sludge delivery pump 7. The variable pore filter can be washed by water and scrubbed with air, water and air by setting the backwash water pump 8 and the backwash fan 10. After backwash, the drainage flows to the backwash drainage pool 5 by itself, and the backwash drainage pump 9 is used to transport the backwash drainage to High-density sedimentation tank inlet pipe. The dosing system includes a lime milk dosing device 11 , a coagulant dosing device 12 , a disinfectant dosing device 13 , a flocculant dosing device 14 , and a sulfuric acid dosing device 15 . On-line monitoring devices that can monitor indicators such as turbidity, conductivity, temperature, flow, pH value, and sludge level are installed in high-density sedimentation tanks, mixing tanks, and variable pore filters.

The lime milk uses quicklime with an effective content of 80%, the coagulant aid uses 0.1-0.3% polyacrylamide solution, the fungicide uses 10% sodium hypochlorite solution, the flocculant uses 10% polyferric sulfate liquid, and the sulfuric acid uses 98% concentrated sulfuric acid liquid.

In this example, the design processing capacity is 900 tons/hour, and the circulating cooling water system transports part of the circulating cooling water to the high-density sedimentation tank through the circulating pump.

Influent water quality: carbonate hardness ≥ 3mmol/L, turbidity ≥ 50NTU, PH value: 7~9. Outlet water quality requirements: Temporary hardness ≤ 1mmol/L, alkalinity ≤ 1mmol/L, turbidity ≤ 3NTU, pH value: 7~8.

Its processing steps are:

a. The circulating cooling water enters the bottom of the high-density sedimentation tank 1 reaction zone, and after passing through the post-rapid coagulation stirring reaction zone and the slow coagulation plug-flow reaction zone, the alum flowers are precipitated and concentrated in the lower part of the sedimentation zone. Part of the concentrated sludge is circulated to the inlet of the reaction tank through the sludge return pump 6, and the remaining sludge is transported to the slurry tank of the desulfurization system through the sludge transport pump 7. The effluent from the upper part of the sedimentation zone flows to the mixing tank 3 by itself through the overflow weir. Lime milk dosing device 11, coagulant dosing device 12, disinfectant dosing device 13, flocculant dosing device 14 and other medicaments are added to the reaction zone of the high-density sedimentation tank to realize the treatment of circulating water.

b. Dosing concentrated sulfuric acid in the mixing tank 3 through the concentrated sulfuric acid dosing device 15, the concentrated sulfuric acid adjusts the pH to 7.5-8.3, and removes bicarbonate in the effluent.

c. After adding concentrated sulfuric acid, it flows to the variable pore filter 4 by itself to further remove suspended solids and reduce turbidity, and the effluent is used as circulating cooling water. The variable pore filter is equipped with a backwash water pump 8 and a backwash fan 10 to realize water washing and air-water air scrubbing of the filter. The backwash effluent flows to the backwash drainage tank 5 by itself, and the backwash drainage is transported to the water inlet pipe of the high-density sedimentation tank through the backwash drainage pump 9.

The above is only a specific embodiment of the utility model, but the structural features of the utility model are not limited thereto, and any changes or modifications made by those skilled in the art within the scope of the utility model are covered by the utility model. In the scope of the new patent.

Claims (7)

1. A lime softening, clarification and filtration treatment system for circulating cooling water, including a high-density sedimentation tank (1) that can be fed into circulating cooling water, characterized in that the high-density sedimentation tank (1) is connected to a mixing tank through pipelines (2), the mixing tank is connected with a variable pore filter tank (3) through pipelines, and the variable pore filter tank is connected with a clear water tank (4) through pipelines, and the clear water tank is connected with a circulating cooling water tank. 2. A circulating cooling water lime softening, clarification and filtration treatment system according to claim 1, characterized in that the bottom of the high-density sedimentation tank (1) is connected to the high The reaction zone of the density sedimentation tank (1) and the bottom of the high density sedimentation tank are also connected to the lime slurry tank of the desulfurization system through the sludge pipe and the sludge delivery pump (7). 3. A circulating cooling water lime softening, clarification and filtration treatment system according to claim 1 or 2, characterized in that a backwash pump ( 8), the variable pore filter is also connected to the backwash fan (10), the variable pore filter is connected to the backwash drainage tank (5) through the pipeline, and the backwash drainage tank is connected with the high-density sedimentation tank through the backwash drainage pump (9) The water inlet pipe of the pool (1) is connected. 4. A circulating cooling water lime softening, clarification and filtration treatment system according to claim 1 or 2, characterized in that the front-end reaction zone of the high-density sedimentation tank (1) is equipped with an agitator (16), and the high-density sedimentation The sedimentation area of the pool (1) is equipped with a mud scraper (17), and electric valves are used for sludge return and transportation. 5. A circulating cooling water lime softening, clarification and filtration treatment system according to claim 1 or 2, characterized in that each valve of the variable pore filter (3) adopts an electric valve. 6. A circulating cooling water lime softening, clarification and filtration treatment system according to claim 1 or 2, characterized in that the coagulation area and flocculation area of the high-density sedimentation tank (1) are connected with a dosing system, and the dosing system It includes a lime milk dosing device (11), a coagulant dosing device (12), a disinfectant dosing device (13), and a flocculant dosing device (14). 7. A circulating cooling water lime softening, clarification and filtration treatment system according to claim 1 or 2, characterized in that the mixing tank (2) is connected with a sulfuric acid dosing device (15) through a dosing pipe.