CN1325138C - Device for removing suspended matter in water - Google Patents

Abstract

The invention provides a filter device for removing suspended solids in water, including tank body, overflow cofferdam and drain pipe, water inlet pipe and water distributor, filter material washer, rectifier, filter material distributor, filter material circulation riser In addition to the air distributor, a suspended matter separator is set between the outlet of the filter material circulation riser and the filter material washer. The structure of the suspended solids separator mainly includes a flat or curved inclined perforated sieve plate or screen, and a sump and a sewage drain pipe connected to it are arranged under the sieve plate or screen. Through the suspended matter separator, most of the suspended matter in the filter material to be cleaned and the water carried during the lifting process of the filter material are separated, and used as a sewage discharge system, while the washing water for cleaning the filter material is circulated back to the filter device . Compared with the prior art, the invention has the characteristics of good effluent quality, high water production rate, small sewage discharge, high concentration multiple of discharged sewage, and is beneficial to further utilization or treatment of discharged sewage.

Description

A device for removing suspended solids in water

technical field

The invention is a water treatment device, more specifically a filter device for removing suspended matter in water.

Background technique

As one of the means of removing suspended solids in water, filtration is not only widely used in urban or industrial sewage advanced treatment and sewage reuse treatment, but also in urban and industrial water supply treatment ( Such as tap water, industrial fresh water, boiler feed water), circulating cooling water treatment and other processes commonly used equipment.

The mechanism of the filter to remove suspended solids is mainly to use the tiny pores inside the filter bed to trap particulate pollutants in the water. Its working process includes two processes: filtration and filter material cleaning. According to different conditions such as filter material, filtration speed, water flow direction, bed depth, water flow driving force, etc., filters can be divided into many different types. According to whether the filter medium moves or not during the filtration process, it can be classified into two types: fixed bed and moving bed.

The fixed bed filter mainly relies on the filter material from the surface of the filter bed to 300-400mm below the surface to intercept suspended solids, which not only has a low dirt holding capacity, but also has obvious and insurmountable shortcomings during use. One of the disadvantages is that continuous filtration of water cannot be achieved, that is, filtration and backwashing cannot be performed at the same time, and the process of filtration and backwashing needs to be switched manually or automatically; High-power cleaning water pump; the third disadvantage is that no matter what cleaning method is used, the filter material is not easy to clean thoroughly. Filter material; the fourth disadvantage is that the length of the filtration cycle is greatly affected by the concentration of suspended solids in the influent, and cannot be fixed or extended. When the concentration of suspended solids in sewage is high, it cannot maintain long-term filtration and frequent backwashing , low water production. Chinese patent 94217260 discloses a fluidized bed backwash filter, which adopts a liftable filter material extrusion plate, which moves upward during backwashing, and uses high-speed jet water to wash the filter material, so that the filter material is in a fluidized state. After flushing, the filter material is compacted with a squeeze disc. This filter is an intermittent operation when in use, and the above-mentioned problems have not been well resolved.

The moving bed filter can solve the problems existing in the fixed bed fixed bed, realize continuous operation, prevent filter material from agglomerating, etc. US4126546 discloses a moving bed filter whose filter material circulation riser is arranged in the center of the filter. In the moving bed filters disclosed in US5462654, US4891142, etc., the filter material circulation riser is also arranged in the center of the filter, the filter material is in the same flow direction as the water flow, and the drainage is arranged in the wire mesh structure in the filter material layer; its parallel flow makes The interception effect of suspended solids in wastewater is poor, and suspended solids are easy to pass through the screen structure with the filtered water, not only the quality of the effluent is poor, but also easy to cause the screen to be blocked; the water flow in the filter space under the screen structure is weak or even stops, resulting in "dead corners", It does not play a filtering role, and the utilization rate of the filter space is low. US5746913, US5277829, etc. disclose a moving bed filter, and the filter material circulation riser is arranged outside the filter. The above-mentioned moving bed filter has the following common disadvantages: 1. The washing of the filter material adopts a simple liquid-solid countercurrent method, the structure of the scrubber is unreasonable, the filter material is unevenly distributed in the scrubber, and cannot fully contact with the washing water , The cleaning water is easy to short circuit, not only the amount of cleaning water is large, but also the washing effect is difficult to guarantee, which in turn affects the quality of the effluent. 2. The sewage discharged from the filter device is all or part of the filter material washing water discharged from the filter material washer. The concentration factor of suspended solids in the drainage is low, and the amount of discharged sewage is large, which is not conducive to the further treatment and utilization of suspended solids; if Circulating part of the washing water of the filter material back to the filter to reduce the external discharge will affect the quality of the filtered water.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a moving bed filter with good effluent quality, high water production rate, small sewage discharge, high sewage concentration multiple, and is conducive to further utilization or treatment of effluent sewage.

In addition to the moving bed filter of the present invention including tank body, overflow cofferdam and drain pipe, water inlet pipe and water distributor, filter material washer, rectifier, filter material distributor, filter material circulation riser and air distributor, A suspended matter separator is arranged between the outlet of the filter material circulation riser and the filter material washer. Wherein the tank body is a cylindrical structure, with a filter material outlet at the bottom, a water inlet pipe is arranged at the middle and lower part of the tank body, and a water distributor is arranged at the part of the water inlet pipe inside the tank body. The overflow cofferdam is a sleeve ring-shaped structure with an upper opening, which is arranged on the upper surface of the tank body. The height of the cofferdam must exceed the upper edge of the tank body, and the drain pipe communicates with the overflow cofferdam. The filter material washer is arranged on the upper part of the tank body, and the filter material washing water mixes with the raw water or enters the bottom of the filter near the filter material outlet. The filter material circulation riser is arranged outside or inside the tank body, and an air distributor for lifting the filter material is arranged at the bottom of the circulation riser. In addition to the suspension separator, other components of the present invention can also adopt structures known in the art.

The key of the present invention is that a suspended matter separator is arranged between the filter material circulation riser and the filter material washer. Through the suspended matter separator, most of the suspended matter in the filter material to be cleaned and the water carried in the lifting process of the filter material are separated, and used as a sewage discharge system; while the filter material washing water of the scrubber is circulated back to the filter device. The structure of the suspended matter separator mainly includes a flat or curved inclined perforated sieve plate (or screen), a sump under the sieve plate and a sewage drain pipe connected to it. The suspended matter separator is arranged at a position higher than the filter material washer, the upper outlet of the filter material circulation riser is placed at the high end of the inclined perforated sieve plate, and the lower end of the inclined perforated sieve plate is connected with the filter material washer. The angle of the inclined perforated sieve plate should allow the filter material to slide down smoothly, generally the included angle with the horizontal line is 15°-75°, preferably 30°-60°. The pore diameter of the sieve plate can be selected according to the particle diameter (D) of the filter material, generally 0.001D-0.8D, preferably 0.05D-0.6D.

Compared with prior art, the present invention has following characteristics:

(1) The baffle type of the scrubber can be selected to ensure that the filter material is evenly distributed and fully in contact with the washing water. Not only the washing effect is good, but also the effluent water quality is good.

(2) A very effective separation process of the filter material and the retentate is completed by using the suspended matter separation device, and the discharged sewage is only a part of the water carried in the process of lifting the filter material, not only the discharged sewage is small, but the water production rate is high , and because of the high concentration of suspended solids, the concentration ratio of the discharged sewage is also high, which is conducive to further utilization or treatment of the discharged sewage.

(3) When the filter material is further cleaned in the scrubber, the concentration of pollutants in the washing water is greatly reduced, and the water volume is small, which can be recycled back to the filter, and the final water recovery rate is high.

(4) The suspended solids separator can fully release the pressure air of the circulating filter material, and make the filter material evenly flow into the scrubber, which helps to stabilize the washing effect and ensure the quality of the effluent.

Description of drawings

Fig. 1 is a structural schematic diagram of a specific embodiment of the filter of the present invention. Wherein, 2 is a filter tank body, 11 and 12 are filter material circulation risers, 13 is a suspended matter separator, and 18 is a filter material washer.

Detailed ways

The filter of the present invention takes the tank body as the main body, and other components are attached to corresponding positions of the tank body as required. The specific structure is: the tank body is a cylindrical structure, and the bottom adopts an inclined surface or a conical surface to form a filter material outlet. The overflow cofferdam is a sleeve ring structure with an upper opening, which is arranged on the upper surface of the tank body, and the height of the cofferdam must exceed the upper edge of the tank body. The drainage pipe communicates with the overflow cofferdam. The water inlet pipe is arranged at the middle and lower part of the tank body, and the part of the water inlet pipe inside the tank body is provided with a water distributor. The filter material washer is set at the upper center of the tank, and the upper part of the washer is provided with a circulating filter material inlet and a washing liquid outlet; the washing water outlet is connected to the washing water drain pipe, and a valve is set on the washing water drain pipe to control the amount of washing liquid; The outlet of the filter material is set in the center of the bottom of the scrubber, and the inlet of the washing liquid can be set on the side of the lower part; the structure of the empty cylinder can be used in the scrubber, but it is better to set a structure such as a baffle plate, and the filter material forms a waterfall between two adjacent baffle plates. . The filter material circulation riser is arranged outside or inside the tank body, preferably outside, the lower part communicates with the filter material outlet of the tank body, and the upper part outlet is located at the high end of the inclined porous sieve plate of the suspended matter separator. The outlet of the filter material of the suspended matter separator communicates with the scrubber. The main air distributor for lifting the filter material is installed at the bottom of the riser, and several auxiliary air distributors are installed on the riser, totaling 1 to 10, preferably 2 to 5, and the distance between each air distributor may be the same or different , preferably the same.

The water separated by the suspended matter separator is discharged from the filter, while the washing water discharged from the washer is returned to the filter.

Multiple air distributors are installed at different positions on the above-mentioned filter material riser, which can overcome the problem that the filter material in the filter material riser is compacted and cannot be restarted after shutdown. By sequentially starting the air distributors at different positions, it is convenient and smooth to start the filter . And it also increases the probability of the filter materials rubbing against each other during the conveying process, which is conducive to the separation of pollutants from the filter material, prevents the filter material from forming agglomerates, and keeps the cleaned filter material in a new state.

The filter material baffle is arranged in the above-mentioned washer, which can greatly improve the washing efficiency of the filter material, reduce the amount of washing water, and ensure the quality of the effluent.

The washing effect of the filter material can be effectively controlled by controlling the amount of washing liquid used in the filter material, so it can adapt to the filtration requirements of different water qualities and maintain consistent water flow and effluent quality, that is, the filter of the present invention has strong adaptability.

The structure and operation mode of the filter of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, realize that a kind of filter of the present invention is mainly made of filter tank 2, water distributor 26, filter bed 3, rectifier 7, air distributor 10,27, external filter material delivery pipe 9,11, 12. Suspended matter separator 13, scrubber 18, filter material distributor 20, and corresponding water inlet and outlet pipelines and valves.

The raw water enters the filter tank 2 from the water inlet 1, and after being distributed by the water distributor 26, it flows upward evenly and passes through the filter bed layer 3, and the suspended matter and other pollutants in the water are trapped in the filter material. The filtered clean water enters the clean water storage area 4 on the upper part of the filter tank, overflows and enters the water outlet area 5, and finally is discharged from the water outlet 6.

While filtering the raw water, the filter material with pollutants trapped in the lower part of the filter tank 2 moves downward continuously, and is lifted to the Suspension separator 13 at the top of the filter tank. After the filter material is distributed by the distribution plate 14 in the separator, the water and pollutants in the filter material pass through the holes, enter the sump, and are discharged from the sewage pipe 16 while sliding down the inclined porous sieve plate. All the compressed air for conveying the filter material is introduced through the air distributors 10 and 27 .

The filter material coming out from the separator 13 only contains a small amount of water and suspended solids, and falls evenly into the scrubber 18 through the pipeline 17 . When the filter material enters the washer, the clear water from the clean water storage area of the filter tank also enters the washer 18 under the action of the liquid level difference to clean the filter material. The size of washing water volume is controlled by valve 22 or 24. The cleaned filter material flows out evenly from the filter material outlet 19 at the lower part of the washer, and can be redistributed by the filter material distributor 20, and then return to the upper part of the filter bed 3 to form a new filter bed, or rely on natural accumulation way to form a new filter bed.

After the cleaning water is discharged from the outlet pipe 21 on the scrubber, it can return to the filter tank through the pipe 23 and the water inlet pipe 1 of the filter tank; The position enters the filter tank, preferably close to the outlet of the filter material. The cleaning water can be powered by pumps or ejectors.

The processing effect of the present invention is illustrated below by examples.

Example 1

The effluent after biochemical treatment of an oil refinery has a concentration of suspended solids of 90 mg/l and a turbidity of 60 degrees. After being treated by the filter equipment of the present invention, the concentration of suspended solids in the filtered water is reduced to 4 mg/l, the turbidity is 3 degrees, the amount of concentrated sewage discharged outside is 1.5% of the influent, and the concentration of suspended solids is 5680 mg/l. And the method of adopting the filter material scrubber to discharge the concentrated sewage keeps the concentration of suspended solids in the filtered water at 4mg/l, the amount of discharged sewage should reach 4% of the influent, and the concentration of suspended solids in the discharged water should be 2120mg/l. If the efflux is reduced to 1.5%, the suspended solids in the filtered water will increase to 15mg/l.

Example 2

In the sewage of a catalyst factory, the concentration of suspended solids in the water is 130mg/l, and the turbidity is 110 degrees. The pollutants are mainly molecular sieves with fine particle diameters and silicate and other production materials. With the filtering equipment of the present invention, the concentration of suspended solids in the treated water is 4.5 mg/l, the turbidity is 2.8 degrees, the external discharge accounts for 2.5% of the treated water, and the suspended solids concentration is 5030 mg/l, which lays a good foundation for the recovery of production raw materials. Foundation. And adopt the method of filter material scrubber to discharge concentrated sewage, when keeping the concentration of suspended matter in the filtered water at 4.5mg/l, the amount of discharged sewage should reach 6% of the influent, and the concentration of suspended matter in the discharged water should be 2100mg/l. If the efflux is reduced to 2.5%, the suspended solids in the filtered water will increase to 28mg/l.

Claims (12)

1. A device for removing suspended solids in water, including a tank body, overflow cofferdam and drain pipe, water inlet pipe and water distributor, filter material scrubber, rectifier, filter material distributor and filter material circulation riser, its It is characterized in that a suspended matter separator is set between the filter material circulation riser and the filter material washer, and the structure of the suspended matter separator includes a plane or curved inclined perforated sieve plate or screen, a water collection tank under the sieve plate or the screen, and The sewage drainage pipe connected with it; the suspended matter separator is set at a position higher than the filter material scrubber, the upper end outlet of the filter material circulation riser is placed at the high end of the inclined perforated sieve plate or screen, and the inclined perforated sieve plate or screen The lower end of the filter is connected with the filter material washer; the main air distributor for lifting the filter material is set at the bottom of the filter material circulation riser. 2. The device according to claim 1, characterized in that the angle between the inclined porous sieve plate or screen mesh and the horizontal line of the suspended matter separator is 15° to 75°, and the hole diameter of the sieve plate is the diameter of the filter material particles 0.001 to 0.8 times of D. 3. The device according to claim 2, characterized in that the angle between the inclined porous sieve plate or the screen mesh and the horizontal line of the suspended matter separator is 30°-60°, and the hole diameter of the sieve plate is the diameter of the filter material particles 0.05-0.6 times of D. 4. The device according to claim 1, characterized in that the tank body is a cylindrical structure with a filter material outlet at the bottom; the water inlet pipe is arranged at the middle and lower part of the tank body, and the part of the water inlet pipe inside the tank body is provided with a water distributor The overflow cofferdam is a sleeve ring structure with an upper opening, which is arranged on the upper surface of the tank body, and the height of the cofferdam must exceed the upper edge of the tank body; the drain pipe communicates with the overflow cofferdam. 5. The device according to claim 1, characterized in that the filter material washer is set in the middle of the upper part of the tank; the filter material washing water is mixed with the raw water or returned to the device at the bottom of the tank close to the filter material outlet. 6. The device according to claim 1, characterized in that the sewage discharged from the drain pipe of the suspended matter separator is used as the sewage discharge system of the device. 7. The device according to claim 4, characterized in that the bottom of the tank adopts an inclined surface or a conical surface to form the outlet of the filter material. 8. The device according to claim 4, characterized in that the upper part of the filter washer is provided with a circulating filter material inlet and a washing water outlet; the washing water outlet is connected to the washing water drain pipe, and the washing water drain pipe is provided with a control The valve for the amount of washing water; the outlet of the filter material is set in the center of the bottom of the scrubber, and the inlet of the washing liquid is set on the side of the lower part. 9. The device according to claim 8, characterized in that several baffle plates are arranged in the filter material washer, and the filter material forms a cascade flow between two adjacent baffle plates. 10. The device according to claim 1, characterized in that the filter material circulation riser is arranged outside or inside the tank body. 11. The device according to claim 1, characterized in that the lower part of the filter material circulation riser communicates with the filter material outlet of the tank body, and the upper part of the outlet is located at the high end of the inclined perforated sieve plate or screen of the suspended matter separator. 12. The device according to claim 1, characterized in that 1 to 10 air distributors are arranged on the riser.