Novel organic waste gas low-temperature adsorption device

Abstract

The utility model relates to equipment for treating organic waste gas, in particular to a novel organic waste gas low-temperature adsorption device which comprises a shell, and a gas outlet and a gas inlet which are respectively formed in the upper end and the lower end of the shell, a cylindrical adsorption mechanism is arranged in the middle of the interior of the shell, the bottom of the adsorption mechanism is sealed by a partition plate, and the top of the adsorption mechanism is blocked by a flow guide cover; a small-aperture cooling coil is wound on the outer surface of the adsorption mechanism; the small-aperture cooling coil is communicated with the outside through a refrigerant medium inlet and a refrigerant medium outlet which are formed in the shell; organic waste gas is led to the packed bed layer through the gas distribution pipe, gas distribution holes are evenly distributed in the gas distribution pipe, it is guaranteed that pollutant gas is evenly distributed, meanwhile, the small-aperture cooling coil pipe is arranged on the surface of an outer silk screen of the packed bed layer, internal flow refrigerants take away adsorption and heat release, and the removal efficiency of pollutants and the utilization rate of adsorption packing are improved.

Description

Technical Field

[0001] The utility model relates to equipment for treating organic waste gas, in particular to a novel low-temperature adsorption device for organic waste gas. Background Art

[0002] In the production process of fine chemical industry, it is inevitable to use organic solvents. However, most organic solvents have the characteristics of low boiling point, low solubility and toxicity. These low boiling point solvents evaporate from the production process, thereby polluting the atmospheric environment and affecting human physical and mental health. For low-solubility organic waste gas, oxidative incineration or adsorption method is often used for removal. For organic waste gas with recycling value or not suitable for incineration (such as organic matter containing halogen elements), adsorption method is often used for removal. Adsorption fillers include activated carbon, zeolite molecular sieve and resin.

[0003] The main principle of the adsorption method is to use the van der Waals force between molecules to intercept organic waste gas pollutants in the pores of the adsorption filler. Organic waste gas pollutants pass through the packing bed from the inside to the outside, and under the action of intermolecular forces, the pollutants are intercepted in the pores of the packing medium, while releasing heat. In addition, under the action of airflow and heat, the saturated vapor pressure of organic waste gas on the surface of the packing pores increases, and some organic pollutants will escape from the pores of the packing and return to the waste gas, forming an adsorption-desorption balance, most of the organic pollutants are removed, and the remaining part enters the emission system.

[0004] Therefore, the main factors that determine the removal efficiency of the adsorption device are the residence time of the organic waste gas in the packing layer and the adsorption temperature of the packing. Traditional adsorption devices are flat-mounted or vertical-mounted. These two filling methods will lead to uneven adsorption of organic waste gas. When replacing the packing, some packing has been saturated with adsorption and can be replaced, but some packing still has adsorption capacity, resulting in waste of packing. In addition, the traditional filling form cannot make full use of the usable space in the adsorption device. When dealing with large air volumes of waste gas, in order to ensure the residence time of the waste gas in the packing layer, it is often designed to be larger, which makes installation inconvenient and the system investment cost will also increase. In order to improve the removal efficiency of organic waste gas, the traditional practice is to thicken the adsorption bed layer, but this practice will lead to increased system resistance and increased operating energy consumption.

[0005] In addition, the traditional adsorption device does not have any cooling measures during the adsorption process. On the one hand, under high outdoor temperature conditions, the heat released by adsorption cannot be dissipated in time, resulting in excessively high temperature in the packing layer, reaching the ignition point of some organic pollutants, posing a risk of fire. On the other hand, the heat generated by the adsorption heat release will greatly reduce the adsorption efficiency, resulting in the inability to effectively remove organic waste gas and substandard emissions. Utility Model Content

[0006] In order to solve the above problems, the utility model provides a novel low-temperature adsorption device for organic waste gas, comprising a shell and an air inlet and an air outlet respectively provided at the upper and lower ends of the shell; a cylindrical adsorption mechanism is centrally arranged inside the shell, the bottom of the adsorption mechanism is sealed by a partition, and the top is blocked by a guide cover; a small-aperture cooling coil is wound around the outer surface of the adsorption mechanism; the small-aperture cooling coil is communicated with the outside through a refrigerant medium inlet and a refrigerant medium outlet provided on the shell;

[0007] Among them, the adsorption mechanism is composed of an inner wire mesh of a packing bed and an outer wire mesh of a packing bed from the inside to the outside; the upper and lower end surfaces of the outer wire mesh of the packing bed are in contact with the inner end surface of the shell to support the entire adsorption mechanism; the partition is fixedly connected to the outer wire mesh of the packing bed; a gap is formed between the inner wire mesh of the packing bed and the outer wire mesh of the packing bed, and the packing bed is formed after the adsorption filler is filled into the gap; the air outlet extends to the inside of the adsorption mechanism with an air distribution pipe that reaches the bottom surface of the fairing and is blocked, and the surface of the air distribution pipe is provided with air distribution holes facing the packing bed.

[0008] Inspection holes are provided at both the upper and lower ends of the shell; unloading ports and loading ports are provided on the surfaces of the partition and the guide cover corresponding to the packing bed layer respectively; a condensate discharge port is provided at the bottom of the shell corresponding to the gap between the wire mesh outside the packing bed layer and the shell; the inspection hole, unloading port, loading port and condensate discharge port can be opened and closed by any known method.

[0009] The height of the packing bed is three quarters of the height of the shell, and the diameter is two thirds of the diameter of the shell.

[0010] Preferably, the air distribution holes have a porosity of 10% on the air distribution pipe, and the air distribution holes are inclined upward by 30°.

[0011] The small-aperture cooling coil is fixedly wound on the outer surface of the wire mesh outside the packing bed layer, and the pipe diameter is 9.52 mm.

[0012] A horizontally arranged dust-proof baffle is provided at the opening of the air distribution hole.

[0013] The utility model provides an air distribution pipe at the waste gas inlet, which leads the organic waste gas to the packing bed. The air distribution pipe is evenly distributed with air distribution holes to ensure uniform distribution of pollutant gases and intercept part of the water mist entrained in the pre-treatment process. Similarly, a small-aperture cooling coil is provided on the surface of the wire mesh outside the packing bed, and the internal refrigerant takes away the adsorption heat, which greatly improves the removal efficiency of pollutants and the utilization rate of the adsorption filler. The cylindrical wrapped packing bed increases the filtration area of ​​the adsorption device of the same scale, effectively reduces the installation space of the adsorption device, reduces the difficulty of installation, and reduces the investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the low-temperature adsorption device for organic waste gas;

[0015] Figure 2 It is a schematic diagram of the cross section of the packing bed and the cooling measures;

[0016] Figure 3 Schematic diagram of the pore structure of the cloth;

[0017] Figure 4 A schematic diagram of the structure of an existing activated carbon environmental protection treatment box;

[0018] In the figure: 1. Shell; 2. Air inlet; 3. Air outlet; 4. Packing bed; 5. Outer wire mesh of packing bed; 6. Inner wire mesh of packing bed; 7. Air distribution holes; 8. Air distribution pipe; 9. Small-aperture cooling coil; 10. Inspection hole; 11. Refrigerant medium inlet; 12. Refrigerant medium outlet; 13. Condensate discharge port; 14. Shield; 15. Discharge port; 16. Loading port. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0020] as follows Figure 1-Figure 3 As shown, under the action of an external centrifugal fan (not shown in the drawings), the exhaust gas (taking the exhaust gas containing dichloromethane pollutants as an example) is input into the pipeline from bottom to top. Under the guidance of the pipeline, the exhaust gas enters the air distribution pipe 8 through the air inlet 2. Since the top of the air distribution pipe 8 extends to the bottom of the guide cover 14 and is blocked by the guide cover 14, the exhaust gas entering the air distribution pipe 8 can only be forced to escape outward from the air distribution holes 7 evenly opened on the wall of the air distribution pipe 8, and impact the packing bed 4 arranged in a ring outside the air distribution pipe 8.

[0021] And because the top and bottom of the packing bed 4 are blocked by the guide cover 14 and the partition respectively, the exhaust gas entering the inner circle of the packing bed 4 can only be forced to cross the entire packing bed 4 and enter between the outer screen 5 of the packing bed and the inner wall of the shell, and then rise along the inner wall of the shell 1 and be discharged through the outlet 3, thereby completing the adsorption and purification of the organic waste gas.

[0022] On this basis, compared with the existing commonly used traditional activated carbon exhaust gas purification structure (such as Figure 4 Compared with the conventional plate-like structure, the utility model designs the activated carbon layer into a cylindrical filler bed 4 structure. This cylindrical wrapping filtration method significantly increases the filtration area of ​​the adsorption device of the same scale and improves the filtration efficiency.

[0023] In addition, the air distribution pipe 8 is inserted into the space formed by the inner circle of the packing bed 4 to form a wrapped ventilation and filtering pattern to ensure the filtration efficiency. The air distribution holes 7 opened on the surface of the packing bed 4 at an upward angle of 30° can not only evenly introduce the exhaust gas into the surface of the packing bed 4 to ensure that the filtration capacity of each part of the packing bed 4 can be equally and fully utilized, but also the hole design and elevation setting of the air distribution holes 7 can be used to limit the flow rate of the exhaust gas and construct an ascending channel for the exhaust gas, so that the water mist in the exhaust gas can be slowed down during the introduction process and fall due to gravity in the ascending channel constructed by the air distribution holes 7 and the air distribution pipe 8, thereby avoiding excessive water vapor from entering the packing bed 4 and affecting its purification ability.

[0024] Furthermore, in order to further ensure or improve the purification capacity of the packed bed 4, the utility model also designs a small-diameter cooling coil 9 for the cylindrical packed bed 4, which is spirally wound on the outer surface of the packed bed 4, and the refrigerant circulating in the coil is used to control the temperature of the packed bed 4. This avoids the situation that the methylene chloride gas releases a large amount of heat during the purification and adsorption process of the waste gas by the packed bed 4, resulting in too high saturated vapor pressure of the packed bed, too much waste gas escapes through the gap of the packed bed 4, and the waste gas concentration reduction effect after adsorption is poor.

[0025] Therefore, compared with the traditional activated carbon exhaust gas purification device, the utility model increases the filtration area, can control the temperature during filtration, and can also remove water mist mixed with the exhaust gas during the filtration process, thereby improving the purification efficiency and purification effect.

[0026] The conventional activated carbon waste gas purification device and the utility model are respectively introduced with dichloromethane pollutants (concentration of 235 mol / m 3 ) and detected the saturated vapor pressure of the packing layer during the adsorption process and the exhaust gas concentration at the outlet, and obtained the following data:

[0027]

[0028] As can be seen from the above, the utility model has a much higher purification efficiency for dichloromethane pollutants than traditional purification equipment. The exhaust gas flow rate and impact angle are affected by the porosity and the inclination angle of the air holes 7. With the good temperature control of the small-aperture cooling coil 9, the saturated vapor pressure of dichloromethane gas is stably maintained at 87.76 mmHg during the adsorption process, so as to avoid the large amount of heat released during the adsorption process causing its own saturated vapor pressure to be too high, and too much heat escapes from the activated carbon gap, resulting in poor effect of reducing the exhaust gas concentration after adsorption. And under the same conditions, the exhaust gas adsorption efficiency of the utility model is more than 50% higher than that of the comparative example. This fully proves that the above-mentioned new low-temperature adsorption device for organic waste gas has good exhaust gas purification efficiency.

[0029] In addition, during the long-term filtration process, the inspection hole 10, the discharge port 15, the loading port 16, and the condensate discharge port 13 can be automatically opened through the electric control valve or other known sealing devices that can be automatically opened and closed, so that the filler in the packing bed 4 can be discharged through the discharge port 15 and the inspection hole 10 at the lower end of the shell 1, and the filler can be added from the inspection hole 10 and the loading port 16 at the upper end of the shell 1, thereby completing the replacement of the filler. At the same time, by opening the condensate discharge port 13 in a timely manner, the condensed water generated by the small-aperture cooling coil 9 during the cooling process can be smoothly discharged, preventing the excessive humidity in the shell 1 from affecting the adsorption performance of the filler.

[0030] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, and these changes and improvements fall within the scope of the utility model to be protected.

Claims

1. A new type of low-temperature adsorption device for organic waste gas, characterized by: The invention comprises a shell (1) and an air inlet (2) and an air outlet (3) respectively provided at the upper and lower ends of the shell (1); a cylindrical adsorption mechanism is centrally arranged inside the shell (1); the bottom of the adsorption mechanism is sealed by a partition plate and the top is blocked by a guide cover (14); a small-aperture cooling coil (9) is wound around the outer surface of the adsorption mechanism; the small-aperture cooling coil (9) is connected to the outside through a refrigerant medium inlet (11) and a refrigerant medium outlet (12) provided on the shell (1); The adsorption mechanism is composed of an inner wire mesh (6) of a packing bed and an outer wire mesh (5) of a packing bed from the inside to the outside; the upper and lower end surfaces of the outer wire mesh (5) of the packing bed are in contact with the inner end surface of the shell (1) to support the entire adsorption mechanism; the partition is fixedly connected to the outer wire mesh (5) of the packing bed; a gap is formed between the inner wire mesh (6) of the packing bed and the outer wire mesh (5) of the packing bed, and the packing bed (4) is formed after the adsorption filler is filled into the gap; the air inlet (2) extends to the inside of the adsorption mechanism and has an air distribution pipe (8) that reaches the bottom surface of the guide cover (14) and is blocked, and the surface of the air distribution pipe (8) is provided with air distribution holes (7) facing the packing bed (4).

2. The novel low-temperature adsorption device for organic waste gas according to claim 1 is characterized in that: Inspection holes (10) are provided at both the upper and lower ends of the shell (1); a discharge port (15) and a loading port (16) are provided on the surfaces of the partition plate and the air guide cover (14) corresponding to the packing bed layer (4); a condensate discharge port (13) is provided at the bottom of the shell (1) corresponding to the gap between the outer wire mesh (5) of the packing bed layer and the shell (1); the inspection hole (10), the discharge port (15), the loading port (16) and the condensate discharge port (13) can all be controlled to open and close by any known method.

3. The novel low-temperature adsorption device for organic waste gas according to claim 1 is characterized in that: The height of the packing bed layer (4) is three quarters of the height of the shell (1), and the diameter is two thirds of the diameter of the shell (1).

4. The novel low-temperature adsorption device for organic waste gas according to claim 1 is characterized in that: The air distribution holes (7) have a porosity of 10% on the air distribution pipe (8), and the air distribution holes (7) are inclined upward at 30°.

5. The novel low-temperature adsorption device for organic waste gas according to claim 1 is characterized in that: The small-aperture cooling coil (9) is fixedly wound on the outer surface of the wire mesh (5) outside the packing bed layer, and the pipe diameter is 9.52 mm.

6. The novel low-temperature adsorption device for organic waste gas according to claim 1 is characterized in that: A horizontally arranged dust-proof baffle is provided at the opening of the air distribution hole (7).

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