High-precision treatment device for VOCs-containing tail gas

Abstract

A high-precision treatment device for tail gas containing VOCs (volatile organic compounds) relates to the technical field of design of devices for treating the tail gas containing the VOCs, and comprises a pre-reaction distributor, a seal between a catalyst filling frame and a reactor main body, a buffer structure and a waste heat recovery structure, the distributor before reaction adopts a porous plate and a crossed inner channel, and the inner channel is of a structure narrowed from top to bottom; high-temperature mud is arranged at a gap where the catalyst filling frame is connected with the pre-reaction distributor main body equipment for sealing, the inlet end of the flue gas distribution buffer is a horn mouth in an inclined plane shape, and a multi-layer silk screen structure is arranged on the inclined plane; the waste heat recovery structure is a three-way light pipe heat exchanger; the tail gas uniform distribution capability can be improved, tail gas containing VOCs can be prevented from escaping from gaps, the flue gas distribution buffer is arranged at the front end of the arranged induced draft fan and has the advantages that the induced draft fan is protected, and a large amount of flue gas can enter the system uniformly, and the temperature of the tail gas entering the system can be increased and the tail gas treatment energy consumption can be reduced due to the arranged waste heat recovery device.

Description

Technical Field

[0001] A high-precision treatment device for tail gas containing VOCs is used for treating tail gas with a slight positive pressure and a large gas volume, and relates to the technical field of design of a device for treating tail gas containing VOCs. Background Art

[0002] VOCs waste gas refers to waste gas composed of volatile organic compounds released during industrial production, chemical reactions, and combustion. It is an organic compound with a saturated vapor pressure greater than 70.91Pa at room temperature, a standard atmospheric pressure of 101.3kPa, a boiling point below 50-260°C, and an initial distillation point equal to 250 degrees Celsius, or any organic solid or liquid that can volatilize at room temperature and pressure; more than 300 species have been identified so far, the most common of which are benzene, toluene, xylene, styrene, trichloroethylene, trichloromethane, trichloroethane, diisocyanate (TDI), diisocyanatoluene, etc.; according to research, if you live in a room polluted by volatile organic compounds for a long time, it can cause dopamine secretion, enhance the nervous system, cause whole body strength, spirit, moist skin, etc., and some may also cause endocrine enhancement and sexual function enhancement. Benzene and xylene can also damage the system and even cause leukemia. These volatile organic compounds have an impact on children's health;

[0003] The current technology for dealing with VOCs is to investigate the VOCs pollution emission links, estimate the total amount of VOCs, formulate VOCs treatment plans, control the source of production processes, and treat VOCs at the end;

[0004] A relatively close invention patent application, CN202311651842.9, discloses a VOCs waste gas treatment device, including a treatment box, a purification mechanism is arranged on the top of the treatment box, a cleaning mechanism is arranged inside the treatment box, a guide box is fixedly connected to the bottom of the treatment box, a filter plate is fixedly connected to the inner wall of the treatment box, and a collection mechanism is arranged on the back of the guide box. This invention has the characteristics of strong practicality and easy separation and cleaning. It uses automated cleaning, which further improves the convenience of device operation compared to traditional manual cleaning, and saves manpower waste to a certain extent.

[0005] According to a technology with the patent number CN 219502418 U, a "VOCs waste gas treatment device" is disclosed, which is applied in the field of waste gas treatment technology. It includes a primary waste gas treatment tank and a secondary waste gas treatment tank. An intake pipe is connected to the primary waste gas treatment tank, and an outlet pipe is connected to the secondary waste gas treatment tank. The primary waste gas treatment tank is filled with waste gas treatment liquid. A suction pipe is connected between the primary waste gas treatment tank and the secondary waste gas treatment tank. A suction fan is fixedly connected to the suction pipe. And a mixing component for treating waste gas is provided in the primary waste gas treatment tank. Its technical effect is that the VOCs waste gas is treated more thoroughly, improving the treatment effect of the VOCs waste gas.

[0006] However, the above-mentioned patented technology is not suitable for applications where the tail gas is slightly positively pressured and has a large volume. In this case, the technical content is prone to generate uneven flow, resulting in the tail gas being easily discharged exceeding the standard. Summary of the Invention

[0007] The purpose of the present utility model is to design a technical environment suitable for slightly positively pressured and large-volume tail gas, including the seal between the pre-reaction distributor, the catalyst loading frame and the reactor body, as well as a buffer structure and a waste heat recovery structure;

[0008] The pre-reaction distributor is arranged at the lower end of the reactor body. The pre-reaction distributor 3 adopts a porous plate and a cross inner channel, and the inner channel narrows from top to bottom;

[0009] Preferably, the porous plate includes six layers of orifice plates. Wire mesh packing is arranged between every two layers of orifice plates. The channels of the upper and lower orifice plates are staggered, and the holes on the orifice plates are not in a straight line;

[0010] The structure that the inner channel narrows from top to bottom means that the diameter of the inlet channel is larger than that of the outlet channel, which is a flared structure.

[0011] High-temperature mud is provided at the gap where the catalyst loading frame is connected to the main equipment of the pre-reaction distributor for sealing;

[0012] The high-temperature mud is filled at the connection between the catalyst loading frame and the pre-reaction distributor equipment to seal the connection gap. It can be easily knocked off during maintenance and needs to be re-applied after the maintenance is completed;

[0013] The flue gas distribution buffer structure includes a draft fan and a flue gas distribution buffer arranged at the front end of the draft fan.

[0014] The waste heat recovery structure includes a smoke exhaust port, and a waste heat recovery device is arranged at the lower end of the smoke exhaust port;

[0015] Preferably: the inlet end of the flue gas distribution buffer is a flared shape with an inclined surface, and multiple layers of wire mesh structures are arranged on the inclined surface;

[0016] Preferably, the waste heat recovery device is a square box three-channel finned tube heat exchanger. The tail gas and air enter from the upper inlet on the side of the square box and exit from the lower outlet on the side of the square box. The flue gas enters from directly below the square box and is discharged from the smoke exhaust port at the top.

[0017] Preferably, a first maintenance access hole is provided at the lower end of the reactor main body near the position connected to the pre-reaction distributor, and a second maintenance inlet is provided on the other side opposite to the smoke distribution buffer.

[0018] Beneficial technical effects:

[0019] 1. The catalyst loading frame adopts a porous plate, a cross inner channel, and a form with a narrowed inner channel, which improves the ability to evenly distribute the tail gas.

[0020] 2. High-temperature mud is provided at the gap between the catalyst loading frame and the reactor main body equipment for sealing, which can prevent the tail gas from escaping from the gap and is convenient for the maintenance of the loading frame.

[0021] 3. A smoke distribution buffer is provided at the front end of the induced draft fan. The provided smoke distribution buffer can protect the induced draft fan and also allow the large-volume flue gas to enter evenly.

[0022] 4. A waste heat recovery device is provided at the front end of the flue gas discharge channel; it increases the temperature of the tail gas entering the system and reduces the energy consumption of tail gas treatment. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the equipment connection of the present invention;

[0024] Among them, the reference numerals are: 1 - reactor main body, 2 - first maintenance access hole, 3 - pre-reaction distributor, 4 - catalyst loading frame, 5 - smoke distribution buffer, 6 - second maintenance inlet, 7 - induced draft fan, 8 - expansion joint, 9 - waste heat recovery device, 10 - inlet, 11 - smoke exhaust port, 12 - outlet. Detailed Embodiments

[0025] In order to further clearly describe the structure of the present invention, the following embodiments of the present invention are given in conjunction with the drawings:

[0026] This system is a device for highly precise treatment of tail gas containing VOCs. The tail gas involved is slightly positively pressurized and has a large volume, which is prone to generate uneven flow in conventional treatment devices and the treated tail gas is prone to exceed the standard.

[0027] This device includes: the seal between the pre-reaction distributor 3 and the catalyst loading frame 4, as well as a buffer structure and a waste heat recovery structure.

[0028] The pre-reaction distributor 3 is arranged in the form of a perforated plate, cross inner channels, and a narrowing inner channel;

[0029] Specifically: for the perforated plate and cross inner channels, the holes on the orifice plate are staggered, not in a straight line, and the narrowing of the inner channel means that the diameter of the hole channel at the inlet end is larger than that at the outlet end;

[0030] Furthermore, there are six layers of perforated plates involved. The staggered arrangement of holes means that the channels of the upper and lower orifice plates are staggered and crossed, and wire mesh packing is arranged between the two orifice plates to separate them;

[0031] High-temperature mud is provided at the gap between the catalyst loading frame 4 and the main equipment of the pre-reaction distributor 3 for sealing. Specifically, the high-temperature mud is filled and smeared at the contact positions between the upper and lower edges of the catalyst loading frame 4 and the reactor main body 1 box body to achieve the sealing of the contact positions between the upper and lower edges of the catalyst loading frame 4 and the reactor main body 1 box body;

[0032] Preferably, the high-temperature mud is smeared after the installation of the upper and lower edges of the catalyst loading frame 4 and the reactor main body 1 box body for the purpose of sealing. This high-temperature mud can be cheaply removed during maintenance and needs to be re-smeared after the maintenance is completed;

[0033] A flue gas distribution buffer 5 is provided at the front end of the induced draft fan 7; the form of the flue gas distribution buffer 5 is a bell mouth plus a multi-layer wire mesh structure; a waste heat recovery device 9 is provided at the front end of the flue gas discharge channel;

[0034] Preferably: the waste heat recovery device 9 is a square box three-channel finned tube heat exchanger. The tail gas and air enter the square box from the inlet 10 at the upper part of the side of the square box, and then are discharged from the outlet 12 at the lower part of the side of the square box. The flue gas enters from directly below the square box and is discharged from the smoke exhaust port 11 at the top;

[0035] According to the mechanism involved above, during implementation, since a perforated plate, cross inner channels and a narrowing design are adopted in the pre-reaction distributor 3 before the tail gas enters the catalyst loading frame 4, the tail gas distribution capacity can be improved after the tail gas enters. To solve the sealing problem of the connection between the reactor main body 1 and the catalyst loading frame 4, high-temperature mud is used to seal the upper and lower edge gaps between the reactor main body 1 equipment and the catalyst loading frame 4, so that the equipment has a good problem of preventing the tail gas from escaping from the gaps during operation; a first maintenance access hole 2 is provided at the connection between the lower end of the reactor main body 1 and the catalyst loading frame 4, and a second maintenance access hole 6 is also provided at the position opposite to the flue gas distribution buffer 5 at the lowermost section of the equipment main body, which plays a role in facilitating maintenance; in order to protect the induced draft fan 7 and allow the large-volume flue gas to enter evenly, a flue gas distribution buffer 5 is added at the front end of the induced draft fan 7, and a multi-layer wire mesh structure is added to the inclined surface of the inlet of the flue gas distribution buffer 5, which can filter out the particulate matter in the flue gas and reduce the wear of the induced draft fan 7 by the flue gas; a square box-type three-channel finned tube heat exchanger is provided at the end of the process. The incoming flue gas passes through the channels in the square box, and the waste heat is recovered, which plays a role in increasing the temperature of the tail gas entering the system and reducing the energy consumption of tail gas treatment. In order to reduce the vibration caused by the operation of the induced draft fan 7, expansion joints 8 are provided between the induced draft fan 7 and the flue gas distribution buffer 5, and between the induced draft fan 7 and the lower end of the waste heat recovery device 9.

Claims

1. A high-precision treatment device for VOCs-containing tail gas, comprising a pre-reaction distributor (3), a catalyst loading frame (4), a reactor body (1), a flue gas distribution buffer structure and a waste heat recovery structure, characterized in that: The pre-reaction distributor (3) is arranged at the lower end of the reactor body (1). The distributor (3) adopts a structure of a porous plate, a cross inner channel, and the inner channel narrows from top to bottom; A high-temperature mud is provided at the gap where the catalyst loading frame (4) is connected to the main equipment of the pre-reaction distributor (3) for sealing; The smoke distribution buffer structure comprises an induced draft fan (7) and a smoke distribution buffer (5) arranged at the front end of the induced draft fan (7); The waste heat recovery structure comprises a smoke exhaust port (11), and a waste heat recovery device (9) is arranged at the lower end of the smoke exhaust port (11).

2. The high-precision treatment device for VOCs-containing tail gas according to claim 1 is characterized in that: The porous plate comprises six layers of porous plates, a wire mesh filler is arranged between every two layers of porous plates, and the channels of the upper and lower porous plates are arranged in a staggered manner.

3. The high-precision treatment device for VOCs-containing tail gas according to claim 1, characterized in that: The structure in which the inner channel narrows from top to bottom means that the diameter of the channel at the entrance end is larger than the diameter of the channel at the exit end, which is a bell-mouth structure.

4. The high-precision treatment device for VOCs-containing tail gas according to claim 1 is characterized in that: A first inspection entrance (2) is provided at the lower end of the reactor body (1) near the position connected to the pre-reaction distributor (3), and a second inspection entrance (6) is provided on the other side opposite to the flue gas distribution buffer (5).

5. The high-precision treatment device for VOCs-containing tail gas according to claim 1, characterized in that: The high temperature mud is filled in the connection between the catalyst loading frame (4) and the pre-reaction distributor (3) equipment, and the high temperature mud connection gap is sealed.

6. The high-precision treatment device for VOCs-containing tail gas according to claim 1, characterized in that: The inlet end of the smoke distribution buffer (5) is a bell mouth in the shape of an inclined surface, and a multi-layer wire mesh structure is arranged on the inclined surface.

7. The high-precision treatment device for VOCs-containing tail gas according to claim 1, characterized in that: The waste heat recovery device (9) is a square box three-channel light tube heat exchanger. The exhaust gas and air enter from the inlet (10) at the upper side of the square box and exit from the outlet (12) at the lower side of the square box. The smoke enters the smoke exhaust port (11) at the top from the bottom of the square box and is discharged.

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