A waste gas concentration mechanism, waste gas collection system and working method thereof

Abstract

The present invention provides a waste gas concentration mechanism, including a closed chamber and a controller, wherein a waste gas source and a gas concentration sensor are arranged in the closed chamber, dust removal equipment and a circulating fan are connected in sequence in the closed chamber, and the circulating fan is connected to a first branch pipe and a second branch pipe respectively, wherein the first branch pipe is provided with an exhaust valve; the second branch pipe is provided with a return air valve and is connected to the closed chamber; the controller is connected to the gas concentration sensor, the exhaust valve, and the return air valve respectively. The present invention is beneficial in that, in view of the characteristics of large exhaust gas volume and low concentration, the continuous emission mode of low-concentration organic waste gas is transformed into an intermittent emission mode of high-concentration waste gas, which greatly reduces the processing load of subsequent purification equipment, and at the same time improves the purification efficiency of the equipment, which is energy-saving and efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of gas purification, and in particular to a waste gas concentration mechanism, a waste gas collection system and a working method thereof. Background Art

[0002] Rubber mixing flue gas contains a variety of toxic and harmful pollutants, mainly odor, dust and volatile organic compounds (VOCs). These pollutants are extremely harmful to the environment and human body. High concentration of odor may cause pulmonary edema or even suffocation and death to those who come into contact with it. Therefore, the task of efficiently collecting and treating waste gas in the rubber mixing section is imminent.

[0003] At present, the main methods for purifying organic waste gas include absorption, adsorption, oxidation and biological methods. However, due to the operation of the rubber refining process and the size of the equipment, the existing rubber refining waste gas collection presents the characteristics of large air volume, low concentration and poor efficiency. Through the VOCs emission concentration test of the rubber refining workshop of a domestic tire factory, it was found that the VOCs concentration at the discharge port of the masterbatch process was less than 50ppm, which brought a huge load burden to the subsequent waste gas collection mechanism, directly resulting in higher initial investment and operating costs. This low-concentration, high-volume organic waste gas treatment is an industrial problem, and there is currently no economical and efficient solution. Summary of the invention

[0004] In view of the above-mentioned defects, the object of the present invention is to provide a waste gas collection system to achieve efficient recovery of "low concentration, large air volume" waste gas, thereby reducing the operating cost of the equipment.

[0005] The present invention provides a waste gas concentration mechanism, comprising a closed chamber and a controller, wherein the closed chamber is provided with a waste gas source and a gas concentration sensor, the closed chamber is connected with a dust removal device and a circulating fan in sequence, the circulating fan is respectively connected with a first branch pipe and a second branch pipe, the first branch pipe is provided with an exhaust valve; the second branch pipe is provided with a return air valve and is connected to the closed chamber; the controller is respectively connected with the gas concentration sensor, the exhaust valve and the return air valve.

[0006] Preferably, a cooling device is also provided on the second branch pipe.

[0007] Preferably, the dust removal equipment is a bag-type dust collector.

[0008] The present invention also provides a waste gas concentration and collection system, including a purification device connected to a chimney, and also including at least one waste gas concentration mechanism as described in claim 1, wherein a first branch pipe of the waste gas concentration mechanism is connected to the purification device.

[0009] Preferably, the purification device is connected to a waste gas collecting main pipe, and the first branch pipe of the waste gas concentration mechanism is connected to the waste gas collecting main pipe.

[0010] Preferably, an exhaust fan is also provided between the chimney and the purification equipment.

[0011] Preferably, the exhaust gas source in the exhaust gas concentration mechanism is a rubber mixer, and the gas concentration sensor is a VOCs concentration sensor.

[0012] Preferably, a dust concentration sensor is also provided in the closed chamber, and the dust concentration sensor is connected to the controller.

[0013] The present invention also provides a working method of the above-mentioned exhaust gas concentration and collection system, comprising the following steps:

[0014] S1. When the VOCs concentration detected by the VOCs concentration sensor is lower than the preset lower limit of the VOCs concentration, and the dust concentration detected by the dust concentration sensor is also lower than the preset lower limit of the dust concentration, the controller opens the return air valve and closes the exhaust air valve. The VOCs waste gas generated by the rubber mixer in the closed room is dust-removed by the dust removal equipment and then returns to the closed room through the second branch pipe;

[0015] S2. When the VOCs concentration detected by the VOCs concentration sensor reaches the preset upper limit of the VOCs concentration, or the dust concentration detected by the dust concentration sensor reaches the preset upper limit of the dust concentration, the controller closes the return air valve and opens the exhaust valve. The VOCs waste gas generated by the rubber mixer in the closed room enters the purification equipment through the first branch pipe after being dust-removed by the dust removal equipment, and is discharged into the atmosphere through the chimney after being processed by the purification equipment.

[0016] S3. When the VOCs concentration and the dust concentration are both lower than their respective preset lower limits, return to step S1.

[0017] Preferably, the preset upper limit value of dust concentration and the preset upper limit value of VOCs concentration are both less than 25% of their respective lower explosion limit concentration values.

[0018] In summary, the present invention has the advantages that:

[0019] First, the present invention proposes a waste gas collection system using a waste gas concentration mechanism. In view of the characteristics of large waste gas volume and low concentration, the continuous emission mode of low-concentration organic waste gas is transformed into an intermittent emission mode of high-concentration waste gas, which greatly reduces the processing load of subsequent purification equipment and improves the purification efficiency of the equipment, which is energy-saving and efficient.

[0020] Second, the exhaust gas concentration mechanism of the present invention uses a closed chamber to seal the exhaust gas source, ensuring that the pollutants are concentrated in the closed chamber, avoiding the phenomenon of carbon black dust flying and foul odor diffusion, improving the air quality in the workshop, and providing protection for the health and safety of workers;

[0021] Third, the exhaust gas concentration mechanisms of the present invention are independent of each other, and the number of working exhaust gas concentration mechanisms can be selected according to the working status of the exhaust gas source. In addition, sensors are arranged in the closed room to monitor the dust and VOCs concentrations in real time, and the opening and closing of the exhaust valve and the return air valve are controlled by the controller, thereby improving the automation degree of the system and ensuring the safe and reliable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the exhaust gas concentration and collection system of the present invention;

[0023] Figure 2 yes Figure 1 Schematic diagram of the exhaust gas concentration mechanism;

[0024] Figure 3 It is a flow chart of the working method of the exhaust gas concentration and collection system.

[0025] Component number description:

[0026] 1. Exhaust gas concentration mechanism

[0027] 1-1 Sealed room

[0028] 1-2 Dust removal equipment

[0029] 1-3 Circulation fan

[0030] 1-4 Cooling equipment

[0031] 1-5 Exhaust valve

[0032] 1-6 Return air valve

[0033] 1-7 Controller

[0034] 1-8 Dust concentration sensor

[0035] 1-9 Gas concentration sensor

[0036] 1-10 Material conveyor belt

[0037] 2 Exhaust gas collection main pipe

[0038] 3. Purification equipment

[0039] 4 Exhaust fan

[0040] 5. Chimney DETAILED DESCRIPTION

[0041] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0042] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the mechanism or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] like Figure 2As shown, the present invention provides a waste gas concentration mechanism, including a closed chamber 1-1 and a controller 1-7. A waste gas source and a gas concentration sensor 1-9 are arranged in the closed chamber 1-1. The specific waste gas source is a rubber mixer, and it can also be other mechanical equipment that generates waste gas during the working process. The gas concentration sensor 1-9 adopts a VOCs concentration sensor, which can detect the waste gas concentration generated during the rubber mixing process. The closed chamber 1-1 seals the rubber mixing chamber to prevent the pollutants generated during the rubber mixing process from spreading and affecting the health of workers. A material transmission window is also provided on the closed chamber 1-1, which is used for the material conveyor belt 1-10 to transfer materials to the rubber mixer, and can also be used as an air supply port in the exhaust stage. The closed chamber 1-1 is also connected to the dust removal equipment 1-2 and the circulating fan 1-3 in sequence. The circulating fan 1-3 is respectively connected to the first branch pipe and the second branch pipe. The first branch pipe is provided with an exhaust valve 1-5; the second branch pipe is provided with a return air valve 1-6, and is connected to the closed chamber 1-1. The dust removal equipment 1-2 adopts a small bag-type dust collector and adopts an on-site dust removal method, which is conducive to simplifying the pipeline and reducing the scale of the system. The second branch pipe is also preferably provided with a cooling device 1-4, and the cooling device 1-4 preferably adopts a partition heat exchanger, which is conducive to eliminating the residual heat in the closed chamber 1-1 and preventing the hot air in the closed chamber 1-1 from expanding and overflowing. The controller 1-7 is respectively connected to the gas concentration sensor 1-9, the exhaust valve 1-5, and the return air valve 1-6. For safety reasons, a dust concentration sensor 1-8 is also provided in the closed chamber 1-1, and the dust concentration sensor 1-8 is connected to the controller 1-7, so that when the dust concentration reaches the safety preset value, the return air valve 1-6 is closed to stop the exhaust gas concentration and avoid dust explosion.

[0045] like Figure 1 As shown, the present invention also provides a waste gas concentration and collection system, including a purification device 3 connected to a chimney 5, the purification device 3 adopts direct combustion or heat storage combustion and other methods to treat waste gas. It also includes at least one independently installed aforementioned waste gas concentration mechanism 1, and the first branch pipe of the waste gas concentration mechanism 1 is connected to the purification device 3. Specifically, the purification device 3 is connected to a waste gas collection main pipe 2, and the first branch pipe of the waste gas concentration mechanism 1 is connected to the waste gas collection main pipe 2. Since multiple rubber mixers may not work at the same time, the waste gas emissions of multiple waste gas concentration mechanisms 1 are not synchronized, and therefore an exhaust fan 4 is also provided between the chimney 5 and the purification device 3. The exhaust fan 4 adopts a variable frequency fan, and the total exhaust volume of the system can be adjusted according to the number of working waste gas concentration mechanisms 1.

[0046] like Figure 3 As shown, the present invention also provides a working method of the above-mentioned exhaust gas concentration and collection system, comprising the following steps:

[0047] S1. When the system just starts working, in the closed room 1-1, the VOCs concentration detected by the VOCs concentration sensor is lower than the preset lower limit of the VOCs concentration, and the dust concentration detected by the dust concentration sensor is also lower than the preset lower limit of the dust concentration. At this time, the controller 1-7 opens the return air valve 1-6 and closes the exhaust valve 1-5. The VOCs waste gas generated by the rubber mixer in the closed room 1-1 is dust-removed by the dust removal equipment 1-2 and then returns to the closed room 1-1 through the second branch pipe. The VOCs or (and) dust concentration in the closed room 1-1 continues to rise until it reaches the preset upper limit of the concentration.

[0048] S2. When the VOCs concentration detected by the VOCs concentration sensor reaches the preset upper limit of the VOCs concentration, or the dust concentration detected by the dust concentration sensor reaches the preset upper limit of the dust concentration, the controller 1-7 closes the return air valve 1-6 and opens the exhaust valve 1-5. The VOCs waste gas generated by the rubber mixer in the closed chamber 1-1 is dedusted by the dust removal equipment 1-2 and then enters the purification equipment 3 through the first branch pipe. After being processed by the purification equipment 3, it is discharged into the atmosphere through the chimney 5. The VOCs or (and) dust concentration in the closed chamber 1-1 continues to decrease.

[0049] S3. When the VOCs concentration and the dust concentration are both lower than their respective preset lower limits, return to step S1.

[0050] Preferably, the preset upper limit of dust concentration and the preset upper limit of VOCs concentration are both less than 25% of their lower explosion limit concentration values ​​to ensure operation safety. The preset lower limit of dust concentration and the preset lower limit of VOCs concentration can be taken as the concentration stability value y (unit: mg / m 3 ) is 2 to 3 times, among which, y0 is the dust or VOCs concentration in the system working environment, in mg / m 3 ; x is the emission of dust or VOCs generated by the rubber mixer in the closed room 1-1, in mg / s; L is the ventilation exhaust volume, in m 3 / s. By presetting reasonable upper and lower limits of the concentration, the system can be kept safe and efficient while avoiding frequent opening of exhaust valves 1-5 and return air valves 1-6, thus extending the service life of the valves and further ensuring the stable operation of the system.

[0051] In summary, the present invention has the advantages that:

[0052] First, the present invention proposes a waste gas collection system using a waste gas concentration mechanism. In view of the characteristics of large waste gas volume and low concentration, the continuous emission mode of low-concentration organic waste gas is transformed into an intermittent emission mode of high-concentration waste gas, which greatly reduces the processing load of subsequent purification equipment and improves the purification efficiency of the equipment, which is energy-saving and efficient.

[0053] Second, the exhaust gas concentration mechanism of the present invention uses a closed chamber to seal the exhaust gas source, ensuring that the pollutants are concentrated in the closed chamber, avoiding the phenomenon of carbon black dust flying and foul odor diffusion, improving the air quality in the workshop, and providing protection for the health and safety of workers;

[0054] Third, the exhaust gas concentration mechanisms of the present invention are independent of each other, and the number of working exhaust gas concentration mechanisms can be selected according to the working status of the exhaust gas source. In addition, sensors are arranged in the closed room to monitor the dust and VOCs concentrations in real time, and the opening and closing of the exhaust valve and the return air valve are controlled by the controller, thereby improving the automation degree of the system and ensuring the safe and reliable operation of the system.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A working method of an exhaust gas concentration and collection system, characterized in that: The invention comprises a closed chamber (1-1) and a controller (1-7), wherein an exhaust gas source and a gas concentration sensor (1-9) are arranged in the closed chamber (1-1), a dust removal device (1-2) and a circulating fan (1-3) are sequentially connected to the closed chamber (1-1), the circulating fan (1-3) is respectively connected to a first branch pipe and a second branch pipe, the first branch pipe is provided with an exhaust valve (1-5); the second branch pipe is provided with a return valve (1-6) and is in communication with the closed chamber (1-1); the controller (1-7) is respectively connected to the gas concentration sensor (1-9), the exhaust valve (1-5), and the return valve (1-6); A dust concentration sensor (1-8) is also provided in the sealed chamber (1-1); the gas concentration sensor (1-9) and the dust concentration sensor (1-8) are both provided close to the exhaust port of the sealed chamber (1-1); The working method of the exhaust gas concentration collection system comprises the following steps: S1. When the VOCs concentration detected by the gas concentration sensor (1-9) is lower than the preset lower limit of the VOCs concentration, and the dust concentration detected by the dust concentration sensor (1-8) is also lower than the preset lower limit of the dust concentration, the controller (1-7) opens the return air valve (1-6) and closes the exhaust air valve (1-5), and the VOCs waste gas generated by the rubber mixer in the closed room (1-1) is dust-removed by the dust removal equipment (1-2) and then returns to the closed room (1-1) through the second branch pipe; S2. When the VOCs concentration detected by the gas concentration sensor (1-9) reaches a preset upper limit of the VOCs concentration, or when the dust concentration detected by the dust concentration sensor (1-8) reaches a preset upper limit of the dust concentration, the controller (1-7) closes the return air valve (1-6) and opens the exhaust air valve (1-5), and the VOCs waste gas generated by the rubber mixer in the closed room (1-1) is dedusted by the dust removal device (1-2) and enters the purification device (3) through the first branch pipe, and is processed by the purification device (3) and then discharged into the atmosphere through the chimney (5); S3. When the VOCs concentration and the dust concentration are both lower than their respective preset lower limits, return to step S1.

2. The working method according to claim 1, characterized in that: The second branch pipe is also provided with a cooling device (1-4).

3. The working method according to claim 1, characterized in that: The dust removal equipment (1-2) is a bag-type dust collector.

4. The working method according to claim 1, characterized in that: It also comprises a purification device (3) connected to the chimney (5), and the first branch pipe is in communication with the purification device (3).

5. The working method according to claim 4, characterized in that: The purification device (3) is connected to a waste gas collecting main pipe (2), and the first branch pipe is connected to the waste gas collecting main pipe (2).

6. The working method according to claim 4, characterized in that: An exhaust fan (4) is also provided between the chimney (5) and the purification equipment (3).

7. The working method according to claim 1, characterized in that: The waste gas source is a rubber mixer, and the gas concentration sensor (1-9) is a VOCs concentration sensor.

8. The working method according to claim 1, characterized in that: The preset upper limit value of dust concentration and the preset upper limit value of VOCs concentration are both less than 25% of their respective lower explosion limit concentration values.

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