CN101721910A - Cross-flow biotrickling filter device for treating gaseous pollutant - Google Patents

Abstract

The invention relates to a cross-flow biological trickle filter device for treating gaseous pollutants, which belongs to the field of gaseous pollutants treatment. The device includes an air intake static pressure zone formed by connecting the air intake baffle (12) to the upper box (3) through flanges, supported by the bottom baffle (13), the support plate (11) and the packing fixed by the flange The packing area that frame (10) constitutes, and exhaust collection pipe (14), spray system, spray liquid circulation system, air inlet (1), air outlet (22), sampling port (2). The structural form in the present invention is conducive to the uniform distribution of the airflow in the air intake static pressure area, which improves the utilization rate of the filler. The spray liquid is evenly distributed by the spray system, so that the distribution of gas and liquid is consistent. The spray direction is cross-flow, and the spray liquid circulation system makes full use of the spray liquid.

Description

A cross-flow bio-trickling filter device for treating gaseous pollutants

technical field

The invention relates to a cross-flow biological trickle filter device for treating gaseous pollutants, which belongs to the field of environmental protection.

Background technique

Biological trickling filtration is the most active research in recent years as a purification method for volatile organic compounds (Volatile Organic Compounds, referred to as VOCs). Compared with conventional VOCs control technology, it has the characteristics of large biomass, easy control of reaction conditions (pH value, humidity), high purification efficiency, low cost and low energy consumption.

The traditional process of purifying VOCs exhaust gas by biological trickling filtration, VOCs gas enters from the bottom of the tower, is purified by contact with biofilm during the flow process, and the purified gas is discharged from the top of the tower. The circulating spray liquid enters the filter tower from the top of the packing layer, flows through the surface of the biofilm and settles at the bottom of the filter tower. The spray liquid is added with N, P, pH regulator, etc. for recycling, and the sediment is discharged out of the system.

The main functions of the spray liquid above the filler of the biological trickling filter are: to provide nutrients other than carbon sources required by microorganisms; to adjust the pH value of the growth environment of microorganisms; to ensure the humidity environment for the survival of microorganisms; to take away metabolites; Hydroscouring maintains the thickness of the biofilm and prevents anaerobic conditions within the biofilm. The spray liquid has a very important influence on the purification effect of the biological trickling filter tower, which is mainly manifested in: ①The flow rate of the spray liquid: the flow rate of the spray liquid is too small, the humidity environment for the survival of microorganisms cannot be guaranteed, and the biological activity is low; If the flow rate of the liquid is too large, it is not conducive to the attachment and growth of microorganisms on the surface of the filler, forming a stable biofilm. ②Distribution of spray liquid: The uneven distribution of spray liquid in the upper and lower layers of the packing layer will seriously affect the purification effect of the biological trickling filter tower.

The equipment used in the biological trickling filter method is a traditional biological trickling filter tower, and the gas and liquid are in contact with each other in the trickling filter tower either downstream or countercurrent. Nutrients in the spray liquid are absorbed and utilized by microorganisms along with the height of the tower, and the distribution of nutrient salt concentration will also be significantly reduced along the axis of the tower, which leads to uneven distribution of humidity and biomass in the trickling filter tower and reduces the efficiency of trickling filtration. The effective degradation space of the tower affects its removal effect, and it is prone to problems of high pressure drop and easy clogging. The existence of these problems increases the equipment volume and investment costs, brings inconvenience to operation and management, and greatly limits the biological drop rate. Further application of filtration method in industrial practice.

Contents of the invention

In order to overcome the above-mentioned defects of the existing devices, the present invention provides a cross-flow bio-trickling filter device, which allows waste gas to pass through the biofilm evenly, and can efficiently treat gaseous pollutants.

In order to achieve the above object, the present invention adopts the following technical scheme: design a biological treatment box, let the exhaust gas enter the box to form a uniform and stable intake area, and the filler area with biofilm attached is arranged on the periphery of the intake area, so that the exhaust gas can Evenly pass through the packing area, become a clean gas, enter the gas collection area, and then be discharged through the exhaust collection pipe. And design a spray mechanism, so that the spray liquid can evenly flow through the packing area. It is also equipped with a spray liquid circulation system to make full use of the spray liquid. The following describes the implementation plan:

The cross-flow biological trickling filter device for treating gaseous pollutants is composed of a biological treatment box, an air inlet connected to the upper part of the biological treatment box, and a spray liquid circulation system connected to the upper part and the lower part of the biological treatment box. Among them, the biological treatment box is provided with an intake static pressure area, a packing area, an air intake area, a gas collection area, an exhaust collection pipe, an air outlet, and a spray system; and, the intake static pressure area is located in the upper area of the biological treatment box The middle part of the bioprocessing box is separated from the enclosure and communicated with the air inlet; the filling area is located in the middle and lower part of the biological treatment box, which is arranged in the shape of an enclosure, and the middle and lower areas of the biological treatment box are divided into a central area and a peripheral area. The former forms The air intake area communicates with the air intake static pressure area, which forms a gas collection area, connected with an exhaust collection pipe, and has an air outlet at the end of the exhaust collection pipe; the spray system is located in the upper area of the biological treatment box and the inlet The peripheral part isolated by the aerostatic pressure zone is the spray mechanism connected with the spray liquid circulation system opposite to the top of the filling zone.

The spray mechanism is an annular liquid distribution tank with uniform small holes at the bottom and a liquid distribution branch pipe connected to the spray liquid circulation system above the liquid distribution tank. Evenly distributed above.

The spray liquid circulation system includes a support plate with uniform small holes at the bottom of the biological treatment tank, a liquid collection tank connected to the bottom of the biological treatment tank under the support plate, a liquid-sealed pipe communicating with the bottom of the liquid collection tank, and The circulating liquid tank connected by the liquid seal pipe, the circulating liquid pump located in the circulating liquid tank, the circulating liquid pipe connected to the outlet of the circulating liquid pump, the high-level liquid tank connected with the circulating liquid pipe, the upper middle part of the high-level liquid tank and the high-level liquid The tank is connected to the overflow pipe of the circulating liquid tank, the solenoid valve is connected to the bottom outlet of the high-level liquid tank, and the liquid distribution tank is connected to the circulating liquid pump, wherein the outlet of the liquid distribution tank is connected to the liquid distribution branch pipe.

Both the air inlet and the air outlet are provided with sampling ports.

The biological treatment box can be composed of an annular intake baffle, an annular bottom baffle, an upper box, a lower box, a packing support frame, a liquid distribution tank, an exhaust collection pipe, an air inlet, and an air outlet, wherein , the air intake baffle is located in the upper box, which divides the upper box into a central area and a peripheral area, the central area is used as the air intake static pressure area and communicates with the air inlet, and the peripheral area is equipped with a spray system; the upper box and the lower box Connected by flanges; the lower box is divided into three areas from the inside to the outside, the inner area is the air intake area, which communicates with the air intake static pressure area, and the middle area is the packing area corresponding to the outer area of the upper box body. A packing support frame is placed in the area, and the packing support frame is supported by the bottom baffle and the support plate and fixed by the flange. The outer area is the gas collection area; the gas collection area is connected with the exhaust collection pipe and the gas outlet in sequence. Wherein, the shape of the biological treatment box can be a cylindrical tank, wherein the exhaust gas collection pipe is connected tangentially to the lower box.

The invention utilizes the air inlet static pressure area to reduce the airflow velocity, and the dynamic pressure is converted into static pressure. After the VOCs waste gas is uniformly distributed inside, it passes from the air inlet area through the packing area to the gas collection area and becomes clean gas. The clean gas is discharged from the gas outlet through the exhaust collection pipe. The spray liquid is pumped into the high-level water tank through the circulating liquid pump and the circulating liquid pipe, and the amount of the spray liquid is controlled by the solenoid valve, and enters the liquid distribution tank from the liquid separation tank through the branch pipe. The liquid distribution tank is located on the top of the filling area, and uniform small holes are set at the bottom. After the spray liquid passes through the filling area, it enters the liquid collection tank through the round hole on the support plate. The excess spray liquid that enters the spray system without the solenoid valve returns to the circulating liquid tank through the overflow pipe. Sampling ports are provided at the air inlet and outlet.

Compared with the existing device, the present invention is improved in that: a special static pressure area is set, and the gas entering the biological treatment box has enough space to convert the dynamic pressure into static pressure, so that the air flow is evenly distributed in the internal space. The spray liquid is distributed through the liquid distribution tank and branch pipe for the first time, and after the second liquid distribution from the circular liquid distribution tank, the liquid is evenly distributed to all parts of the packing area. The gas and liquid distribution of the packing is uniform, and the air flow passes through The filling direction and the liquid spraying direction are cross-flow. The device can reduce the height of the traditional biological trickling filter device and reduce the height difference of the spray liquid distribution. At the same time, the spray liquid is uniformly distributed in the direction of the air flow through the packing, the air flow is evenly distributed, and the packing area exposed to high-concentration gas is increased.

Description of drawings

Fig. 1 is the structural representation of biological treatment box among the present invention;

Fig. 2 is the top view of the main structure of the device of the present invention;

Fig. 3 is a schematic diagram of the structure and working principle of the device of the present invention.

In the figure: A, air intake static pressure area, B, air intake area, C, packing area, D, gas collection area, E, spray system, 1, air inlet, 2, sampling port, 3, upper box , 4. Lower box body, 5. Liquid collection tank, 6. Liquid separation tank, 7. Liquid distribution branch pipe, 8. Direct connection pipe, 9. Liquid distribution tank, 10. Packing support frame, 11. Support plate, 12, Intake baffle, 13. Bottom baffle, 14. Exhaust collection pipe, 15. Liquid seal pipe, 16. Circulating liquid tank, 17. Circulating liquid pump, 18. Circulating liquid pipe, 19. High level liquid tank, 20, Electromagnetic valve, 21, overflow pipe, 22, air outlet.

Detailed ways

Specific embodiments of the present invention are described below in conjunction with accompanying drawing:

The device mainly includes air intake static pressure area A, air intake area B, packing area C, gas collection area D, exhaust pipe 14, spray system E and spray liquid circulation system. As shown in Figure 1, the air inlet static pressure area A communicates with the air inlet 1, which is conducive to the decrease of the airflow speed, and the dynamic pressure is converted into static pressure. After the gas is evenly distributed inside, the air inlet area B is formed, and then passes through the packing area C. The clean gas treated in the filling area C enters the gas collection area D, and is discharged from the gas outlet 22 through the exhaust pipe 14 . The spray system E is located above the filling area C and is connected with the spray liquid circulation system. Sampling ports are provided at the inlet and outlet.

The device is mainly composed of a tank-shaped biological treatment tank and a spray liquid circulation system (as shown in Figures 2 and 3). The biological treatment box is composed as follows: the biological treatment box mainly includes an upper box body 3 and a lower box body 4, the upper box body 3 and the lower box body 4 are connected by flanges, and the lower box body 4 and the liquid collection tank 5 are connected by flanges. There are support plates 11 between them. The center of the top of the upper box 3 is connected to the air inlet 1, and the air inlet 1 is provided with a sampling port 2; the air intake baffle 12 is connected to the upper box 3 through a flange to form an air inlet static pressure area A; in the lower box 4 It includes packing area C composed of packing support frame 10, air intake area B inside packing area C, and gas collection area D outside packing area C; packing support frame 10 is supported by bottom baffle plate 13 and support plate 11, and the bottom baffle plate 13 and the support plate 11 are fixed by flanges; the area corresponding to the support plate 11 and the packing support frame 10 is provided with many uniform small holes, which can make the spray liquid flow out to the sump 5; the center of the bottom of the sump 5 is connected to the liquid seal Tube 15 is connected. The devices used in the liquid collecting tank 5 and the liquid seal pipe 15 and the following existing spray liquid circulation system constitute the spray liquid circulation system in the present invention: the circulation liquid tank 16, the circulation liquid pump 17, the circulation liquid pipe 18, the high position Liquid tank 19, overflow pipe 21, solenoid valve 20, liquid separation tank 6, liquid distribution branch pipe 7, liquid distribution tank 9. The biological treatment box is also equipped with: a spray system E formed by connecting the liquid distribution tank 9 and the liquid distribution branch pipe 7 through the direct connection pipe 8. The liquid distribution branch pipe 7 is evenly arranged in four sets, and uniform small holes are arranged at the bottom of the liquid distribution tank 9 to form a uniform The spray liquid evenly flows to the filling area C; the exhaust collection pipe 14 connected to the gas collection area D, the exhaust collection pipe 14 is connected tangentially with the lower box body 4 (as shown in Figure 3), and the gas outlet 22 and sampling Mouth 2.

The liquid flows evenly through the spray system E to the filling area C, and the VOCs waste gas can pass through the filling area C evenly through the inlet static pressure area A. The device can maintain uniform biofilm activity in the filling area and can efficiently treat waste gas. The invention is applicable to the treatment of insoluble and refractory organic waste gas and malodorous gas with low air volume and low concentration, and has wide practicability.

Claims (6)

1. cross-flow biotrickling filter device of handling gaseous contaminant is by biological treatment case, the air inlet (1) that links to each other with the biological treatment upper box part and the spray liquid circulatory system formation that links to each other with the bottom with the biological treatment upper box part; It is characterized in that: be provided with air admission static pressure district (A), packing area (C), air inlet area (B), plenum zone (D), exhaust gas collection pipe (14), gas outlet (22) and spray system (E) in the biological treatment case; Wherein, (A is positioned at the middle part in biological treatment upper box part zone, is separated out by enclosing, communicates with air inlet (1) in the air admission static pressure district; Packing area (C) is arranged in biological treatment case, bottom, being enclosing shape is provided with, to carry out a biological disposal upon in the case, lower area is divided into middle section and outer peripheral areas, the former forms air inlet area (B), communicate with air admission static pressure district (A), the latter forms plenum zone (D), is connected with exhaust gas collection pipe (14), is provided with gas outlet (22) at exhaust gas collection pipe (14) tail end; Spray system (E) is positioned at the peripheral position isolated with air admission static pressure district (A) in biological treatment upper box part zone, is the spraying mechanism that with the spray liquid circulatory system link to each other relative with top, packing area (C).

2. a kind of cross-flow biotrickling filter device of handling gaseous contaminant as claimed in claim 1, it is characterized in that: described spraying mechanism is the cloth liquid bath (9) of bottom annular that uniform small pores is set and the cloth liquid arm (7) that links to each other with the spray liquid circulatory system that is positioned at cloth liquid bath (9) top, wherein cloth liquid arm (7) is provided with more than two, and evenly arranges in cloth liquid bath (9) top.

3. as each described a kind of cross-flow biotrickling filter device of handling gaseous contaminant in the claim 2, it is characterized in that: the described spray liquid circulatory system comprises the gripper shoe that is provided with uniform small pores (11) that is positioned at biological treatment case bottom, be positioned at the following collecting tank (5) that is connected with biological treatment case bottom of gripper shoe (11), the liquid sealing pipe (15) that communicates with collecting tank (5) bottom, the circulation liquid bath (16) that is communicated with liquid sealing pipe (15), be positioned at the recycle liquid pump (17) of circulation liquid bath (16), the circulation fluid pipe (18) that is connected with recycle liquid pump (17) outlet, the high-order liquid bath (19) that is communicated with circulation fluid pipe (18), the overflow pipe (21) that is positioned at high-order liquid bath (19) middle and upper part and communicates with high-order liquid bath (19) and circulation liquid bath (16), the magnetic valve (20) that is connected with high-order liquid bath (19) outlet at bottom, the branch liquid bath (6) that communicates with recycle liquid pump (17) wherein divides the outlet of liquid bath (6) to be communicated with cloth liquid arm (7).

4. as each described a kind of cross-flow biotrickling filter device of handling gaseous contaminant among the claim 1-3, it is characterized in that: air inlet (1), gas outlet (22) all are provided with thief hatch (2).

5. a kind of cross-flow biotrickling filter device of handling gaseous contaminant as claimed in claim 4, it is characterized in that: the biological treatment case is by the air inlet baffle plate (12) of annular, the bottom baffle (13) of annular, upper box body (3), lower part box (4), filler bracing frame (10), cloth liquid bath (9), exhaust gas collection pipe (14), air inlet (1), gas outlet (22) is formed, wherein, air inlet baffle plate (12) is positioned at upper box body (3), upper box body (3) is divided into middle section and outer peripheral areas, middle section is communicated with air inlet (1) as air admission static pressure district (A), and outer peripheral areas is provided with spray system (E); Upper box body (3) is connected by flange with lower part box (4); Lower part box (4) is divided into three zones from inside to outside, internal layer area is air inlet area (B), communicate with air admission static pressure district (A), middle layer region is the packing area (C) corresponding with the outer peripheral areas of upper box body (3), this zone is placed with filler bracing frame (10), filler bracing frame (10) is supported by bottom baffle (13), gripper shoe (11) and is fixed by flange, and outer zone is plenum zone (D); Plenum zone (D) is connected successively with exhaust gas collection pipe (14), gas outlet (22).

6. a kind of cross-flow biotrickling filter device of handling gaseous contaminant as claimed in claim 6 is characterized in that: the biological treatment case is the tubular tank body, wherein exhaust gas collection pipe (14) and tangent connection of lower part box (4).

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