Dust-containing gas trapping system

Abstract

The utility model belongs to the technical field of environmental protection, and particularly relates to a dust-containing gas trapping system. Comprising a first-stage washing tank, a second-stage washing tank and a demister which are sequentially communicated through a gas phase pipeline, and a gas inlet of the first-stage washing tank is connected with a gas phase outlet of reaction equipment; the outlet end parts of the gas-phase pipelines in the first-stage washing tank and the second-stage washing tank extend below the liquid level, and crushing structures are arranged at the outlets; the first-stage washing tank and the second-stage washing tank are respectively connected with a washing liquid supply pipeline, the demister is connected with a vacuum pipeline, and emptying ports of the first-stage washing tank, the second-stage washing tank and the demister are respectively connected to the temporary storage tank; a control system is further included. A two-stage washing structure is adopted, an outlet of a gas phase pipeline in the tank extends to the position below the liquid level and is matched with a sawtooth-shaped crushing structure, dust-containing gas can be fully guided into washing liquid, bubbles are broken to avoid secondary escape of dust, the fine dust collecting efficiency is greatly improved, meanwhile, collected washing waste liquid can be conveyed to a downstream recycling workshop section, and the recycling effect is good. And cyclic utilization of resources is realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of environmental protection technology, more particularly to dust-containing gas trapping system. BACKGROUND

[0002] In the field of environmental protection technology, the effective trapping of dust-containing gas is a key link in industrial production to ensure the normal operation of equipment, reduce environmental pollution and avoid safety risks. At present, in the process of industrial production (such as calcium sulfide production, anhydrous hydrogen fluoride production and silane gas related inorganic material process), solid feeding is easy to produce dust, and the dust particle size is extremely small in some scenes (such as calcium sulfide production, calcium hydroxide powder particle size is about 10 μm), which leads to the low separation efficiency of traditional cyclone separation equipment for fine components, and it is difficult to effectively trap dust. These uncollected dust is easy to enter the subsequent vacuum pipeline or unit, causing pipeline blockage, equipment damage and affecting production continuity; at the same time, in the production of anhydrous hydrogen fluoride, the dust content of the reaction furnace slag tail gas is high, and the existing dust removal system often cannot realize efficient purification, and a large amount of dust emission will cause serious environmental pollution; in addition, for special materials such as silane gas, it is easy to burn when discharged into the air, which has the risk of backfire explosion, and the traditional low-pressure state of the flame arrester and other facilities cannot effectively prevent backfire, and cannot realize synchronous dust collection, which cannot meet the environmental protection requirements and cannot guarantee the production safety. Furthermore, the existing part of the water washing dust removal system lacks precise liquid level control and pressure balance mechanism, which is easy to cause dust secondary escape due to bubbles, liquid level fluctuation affects dust removal effect and other problems, which further reduces the stability and reliability of dust-containing gas trapping. Therefore, an efficient dust-containing gas trapping system is needed, which can effectively trap fine dust, meet environmental protection and safety requirements, and has stable control function, to solve the problems of the prior art. CONTENT OF THE UTILITY MODEL

[0003] According to the above deficiencies in the prior art, the purpose of the utility model is to provide a dust-containing gas trapping system, which adopts a two-stage water washing structure of a primary and secondary water washing tank in series, the gas phase pipeline outlet in the tank is extended to below the liquid surface and cooperates with the sawtooth crushing structure, which can fully introduce the dust-containing gas into the washing liquid, break the bubbles to avoid dust secondary escape, greatly improve the fine dust trapping efficiency, and the collected washing waste liquid can also be transported to the downstream recovery section to realize the recycling of resources.

[0004] The utility model is implemented by adopting the following technical solutions:

[0005] The dust-containing gas capturing system comprises a primary water washing tank, a secondary water washing tank and a demister connected in sequence through a gas phase pipeline, the gas inlet of the primary water washing tank is connected with the gas phase outlet of the reaction equipment, the outlet end of the gas phase pipeline in the primary water washing tank and the secondary water washing tank extends below the liquid level, and a broken structure is arranged at the outlet, the primary water washing tank and the secondary water washing tank are respectively connected with a washing liquid supply pipeline, the demister is connected with a vacuum pipeline, the exhaust outlets of the primary water washing tank, the secondary water washing tank and the demister are respectively connected to a temporary storage tank, and a control system is further included.

[0006] The broken structure is a sawtooth structure.

[0007] The primary water washing tank, the secondary water washing tank, the demister and the temporary storage tank are respectively connected to a balance gas pipeline through a pipeline, a switch valve is arranged on the balance gas pipeline, and the switch valve is electrically connected with the control system.

[0008] Liquid level meters are respectively arranged on the primary water washing tank, the secondary water washing tank, the demister and the temporary storage tank, and the liquid level meters are electrically connected with the control system.

[0009] The washing liquid supply pipeline is connected to the pipelines of the primary water washing tank and the secondary water washing tank, and an on-off valve is arranged on each pipeline, and the on-off valves are electrically connected with the control system.

[0010] The outlet of the temporary storage tank is connected to a downstream recovery section through a delivery pump.

[0011] The dust-containing gas capturing system works as follows:

[0012] Firstly, the washing liquid (such as dilute ammonia water) is injected into the primary water washing tank and the secondary water washing tank through the washing liquid supply pipeline until the liquid level meter monitors that the preset appropriate liquid level is reached, at which time the on-off valves on the washing liquid pipelines are closed. Then, the vacuum pipeline connected with the demister is opened to perform vacuumizing operation, so that the interiors of the primary water washing tank, the secondary water washing tank and the demister are maintained in the required vacuum state; at the same time, the bottom valves of the temporary storage tank connected to the bottom exhaust outlets of the primary water washing tank, the secondary water washing tank and the demister are kept in the open state, and since the interiors of the water washing tanks and the demister are in vacuum, a pressure difference is formed with the temporary storage tank, so that the washing liquid liquid level in the tank is kept stable and does not fall.

[0013] When the reaction equipment operates to generate a dust-containing gas phase, the gas phase enters a first-stage water washing tank through a gas phase outlet of the reaction equipment, because the gas phase pipeline outlet in the first-stage water washing tank extends below the liquid level of the washing liquid, the dust-containing gas directly rushes into the washing liquid, and most of the dust is adsorbed by the washing liquid; at the same time, the sawtooth-shaped breaking structure at the pipeline outlet can effectively break the gas bubbles generated in the washing liquid, so as to avoid the bubbles from carrying the un-adsorbed dust to escape again into the gas phase space. After the gas phase is washed in the first stage, the gas phase enters a second-stage water washing tank through a gas phase pipeline, and the second-stage water washing tank has the same structural design as the first-stage water washing tank. The gas phase rushes into the washing liquid again to be deeply purified, so as to further remove residual dust. After the gas phase is washed in two stages, the gas phase then enters a mist eliminator, in which the water mist carried in the gas phase is removed, so as to ensure that the gas phase entering the subsequent vacuum system is dry, and to avoid the influence of the water mist on the vacuum system.

[0014] During the system operation, the liquid level meters on the first-stage water washing tank, the second-stage water washing tank, the mist eliminator and the temporary storage tank monitor the liquid levels in real time, and transmit data to the control system. When the liquid level in the first-stage water washing tank, the second-stage water washing tank or the mist eliminator rises to a preset upper limit due to dust adsorption, gas phase carrying of a small amount of liquid and other factors, the control system immediately interlocks to open the on-off valve on the balance gas pipeline, so as to realize vacuum breaking by connecting the balance gas pipeline, so that the pressure in the tank is restored to close to normal pressure, and the liquid level in the tank is lowered. When the liquid level meter detects that the liquid level is below the upper limit, the control system interlocks to close the on-off valve, and the tanks are maintained in a vacuum state again. If the liquid level in the first-stage water washing tank or the second-stage water washing tank decreases to a preset lower limit due to washing liquid loss and other reasons, the control system interlocks to open the on-off valve on the washing liquid pipeline of the corresponding tank, so as to supplement the washing liquid through the washing liquid supply pipeline, until the liquid level rises to an appropriate liquid level, and then the on-off valve is closed. For the temporary storage tank, when the liquid level meter detects that the waste liquid (washing liquid containing dust) collected in the temporary storage tank reaches the upper limit, the control system starts the delivery pump at the outlet of the temporary storage tank, so as to deliver the temporary storage liquid to the downstream recovery section for resource recycling, so as to avoid overflow of the temporary storage tank. In addition, the first-stage water washing tank and the second-stage water washing tank are also provided with sight glasses, through which the operator can observe the state of the washing liquid in the tank. When it is observed that the washing liquid becomes a suspension due to adsorption of a large amount of dust, and the adsorption capacity is reduced, the suspension can be manually controlled to be discharged to the temporary storage tank, and then new washing liquid is injected through the washing liquid supply pipeline, so as to ensure the water washing and purification effect.

[0015] Compared with the prior art, the utility model has the advantages that:

[0016] (1) The dust-containing gas capturing system, which adopts a two-stage water washing structure of a primary water washing tank and a secondary water washing tank connected in series, and the outlet of the gas phase pipeline in the tank extends below the liquid surface, cooperates with the sawtooth-shaped crushing structure at the outlet, can fully guide the dust-containing gas into the washing liquid, break the bubbles generated by the gas at the same time, avoid the secondary escape of the dust with the bubbles, greatly improves the capturing efficiency of the fine dust, effectively prevents the dust from blocking the vacuum pipeline and the unit, and guarantees the stable operation of the production equipment;

[0017] (2) For the high dust-containing condition, the dust-containing gas capturing system adopts the design of two-stage water washing tanks combined with a mist eliminator, can efficiently purify the tail gas, reduces the dust emission, and reduces environmental pollution; at the same time, the washing waste liquid collected by the temporary storage tank can be sent to the downstream recovery section through the delivery pump, realizes the recycling of resources, and further improves the environmental protection value;

[0018] (3) The water washing structure of the dust-containing gas capturing system can be used as a water seal system, for the special materials which are easy to burn and have the risk of backfire explosion, can more effectively realize the fire blocking effect than the traditional fire arrester under the low pressure state, simultaneously collects the solid dust carried by the materials, and takes into account the safety and environmental protection requirements; in addition, the provision of the control system improves the stability and automation degree of the system operation, reduces the manual intervention, and reduces the operation risk. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic view of the dust-containing gas capturing system;

[0020] Figure 2 is Figure 1 is an enlarged schematic view of A in the middle;

[0021] In the figure: 1, primary water washing tank; 2, secondary water washing tank; 3, mist eliminator; 4, crushing structure; 5, washing liquid supply pipeline; 6, vacuum pipeline; 7, temporary storage tank; 8, balance gas pipeline; 9, on-off valve; 10, liquid level meter; 11, on-off valve; 12, delivery pump. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme of the utility model more clearly, in the following, combined with the drawings, the utility model is further explained in detail.

[0023] Example 1

[0024] For example, Figures 1-2The dust-containing gas capturing system comprises a first water washing tank 1, a second water washing tank 2 and a demister 3 connected in sequence through a gas phase pipeline, the gas inlet of the first water washing tank 1 is connected with the gas phase outlet of a reaction device, the outlet end of the gas phase pipeline in the first water washing tank 1 and the second water washing tank 2 extends below the liquid level, and a broken structure 4 is arranged at the outlet, the first water washing tank 1 and the second water washing tank 2 are respectively connected with a washing liquid supply pipeline 5, the demister 3 is connected with a vacuum pipeline 6, the exhaust outlets of the first water washing tank 1, the second water washing tank 2 and the demister 3 are respectively connected with a temporary storage tank 7, and a control system is further included.

[0025] The broken structure 4 is a zigzag structure.

[0026] The first water washing tank 1, the second water washing tank 2, the demister 3 and the temporary storage tank 7 are respectively connected with a balance gas pipeline 8 through a pipeline, a switch valve 9 is arranged on the balance gas pipeline 8, and the switch valve 9 is electrically connected with the control system.

[0027] Liquid level meters 10 are respectively arranged on the first water washing tank 1, the second water washing tank 2, the demister 3 and the temporary storage tank 7, and the liquid level meters 10 are electrically connected with the control system.

[0028] The washing liquid supply pipeline 5 is connected with the pipeline of the first water washing tank 1 and the second water washing tank 2, and on-off valves 11 are respectively arranged on the pipelines, and the on-off valves 11 are electrically connected with the control system.

[0029] The outlet of the temporary storage tank 7 is connected with a downstream recovery section through a delivery pump 12.

[0030] When working, the specific process is as follows:

[0031] Taking the dust-containing gas capturing in the production process of calcium thiosulfate as an example, first, according to the production process requirements of calcium thiosulfate, the washing liquid is determined to be dilute ammonia water, the dilute ammonia water is injected into the first water washing tank 1 and the second water washing tank 2 through the washing liquid supply pipeline 5, and the liquid level meters 10 on the tank bodies are observed at the same time, when the liquid level reaches the preset height (ensuring that the gas phase pipeline outlet is inserted below the liquid surface by 300 mm), the on-off valves 11 on the washing liquid pipelines of the first water washing tank 1 and the second water washing tank 2 are closed. Then, the vacuum pipeline 6 connected with the demister 3 is opened, the vacuum system is started to perform vacuumizing, and the interiors of the first water washing tank 1, the second water washing tank 2 and the demister 3 are maintained at a vacuum degree of 0.06 MPa, at this time, the bottom valves of the temporary storage tank 7 connected with the bottom exhaust outlets of the first water washing tank 1, the second water washing tank 2 and the demister 3 are kept open, the liquid level of the dilute ammonia water in the first water washing tank 1 and the second water washing tank 2 is stabilized by the pressure difference between the internal vacuum and the temporary storage tank 7, and the dilute ammonia water liquid level does not fall.

[0032] Subsequently, the calcium thiosulfate production equipment began to run, the hydrogen oxide calcium dust (particle size of about 10 μm) generated during the feeding process was introduced into the gas phase pipeline of the first water washing tank 1 through the gas phase outlet of the reaction equipment, the gas phase was flushed into the dilute ammonia water from the pipeline outlet (located 300 mm below the dilute ammonia water liquid level), the hydrogen oxide calcium dust was fully contacted with the dilute ammonia water and was adsorbed; at the same time, the sawtooth-shaped broken structure 4 of the pipeline outlet broke the bubbles generated by the gas phase in time to prevent the bubbles from carrying the unadsorbed dust escaping. After the two-stage water washing, the gas phase was introduced into the second water washing tank 2 through the gas phase pipeline, the gas phase pipeline outlet in the second water washing tank 2 was also inserted into the dilute ammonia water liquid level below 300 mm, and the gas phase was flushed into the dilute ammonia water again for secondary purification to further remove the residual hydrogen oxide calcium dust. The gas phase after completing the two-stage water washing was then introduced into the mist eliminator 3, a layer of 100 mm metal mesh demister was arranged in the mist eliminator 3, the water mist in the gas phase was intercepted by the metal mesh to realize gas-liquid separation, and the gas phase after removing the water mist was introduced into the vacuum system.

[0033] During the entire operation process, the liquid level meters 10 of the first water washing tank 1, the second water washing tank 2, the mist eliminator 3 and the temporary storage tank 7 transmitted the liquid level data to the control system in real time. When the liquid level in the first water washing tank 1 or the second water washing tank 2 slightly rose to the upper limit due to dust adsorption, the control system immediately interlocked to open the on-off valve 9 on the balance gas pipeline 8, the vacuum was broken through the connection of the balance gas pipeline 8, the liquid level decreased, and when the liquid level decreased to below the upper limit, the on-off valve 9 was automatically closed, and the vacuum state in the first water washing tank 1 or the second water washing tank 2 was restored; if the liquid level in the first water washing tank 1 or the second water washing tank 2 decreased to the lower limit, the control system interlocked to open the corresponding on-off valve 11 of the first water washing tank 1 or the second water washing tank 2, and after the dilute ammonia water was supplemented to the preset liquid level, the on-off valve 11 was closed. The operator regularly observed the state of the dilute ammonia water in the first water washing tank 1 and the second water washing tank 2 through the sight glasses, when the dilute ammonia water was found to be a suspension and the adsorption capacity decreased, the suspension was discharged to the temporary storage tank 7 through the discharge port, and then new dilute ammonia water was injected. When the liquid level meter 10 of the temporary storage tank 7 monitored that the liquid level reached the upper limit, the delivery pump 12 of the temporary storage tank 7 outlet was started to deliver the temporarily stored dilute ammonia water containing dust to the downstream recovery section for recycling.

Claims

1. A dust-laden gas capture system, characterized in that: The invention comprises a primary water washing tank (1), a secondary water washing tank (2) and a demister (3) which are connected in sequence through a gas phase pipeline, wherein the air inlet of the primary water washing tank (1) is connected to the gas phase outlet of the reaction equipment; the outlet ends of the gas phase pipelines in the primary water washing tank (1) and the secondary water washing tank (2) extend below the liquid surface, and a crushing structure (4) is provided at the outlet; the primary water washing tank (1) and the secondary water washing tank (2) are respectively connected to a washing liquid supply pipeline (5); the demister (3) is connected to a vacuum pipeline (6); the exhaust ports of the primary water washing tank (1), the secondary water washing tank (2) and the demister (3) are respectively connected to a temporary storage tank (7); and a control system is also included.

2. The dust-laden gas capture system according to claim 1, characterized in that: The crushing structure (4) is a sawtooth structure.

3. The dust-laden gas capture system according to claim 1, characterized in that: The primary water washing tank (1), the secondary water washing tank (2), the demister (3) and the temporary storage tank (7) are respectively connected to a balancing gas pipeline (8) through pipelines. A switch valve (9) is provided on the balancing gas pipeline (8), and the switch valve (9) is electrically connected to the control system.

4. The dust-laden gas capture system according to claim 1, characterized in that: The first-stage water washing tank (1), the second-stage water washing tank (2), the demister (3) and the temporary storage tank (7) are respectively provided with a liquid level meter (10), and the liquid level meter (10) is electrically connected to the control system.

5. The dust-laden gas capture system according to claim 1, characterized in that: The washing liquid supply pipeline (5) is connected to the pipeline of the primary water washing tank (1) and the secondary water washing tank (2), and an on-off valve (11) is provided on each pipeline. The on-off valve (11) is electrically connected to the control system.

6. The dust-laden gas capture system according to claim 1, characterized in that: The outlet of the temporary storage tank (7) is connected to the downstream recovery section via a delivery pump (12).

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