Laboratory fuming cupboard acid waste gas treatment system

Abstract

The utility model relates to the field of laboratory fuming cupboard acid waste gas treatment, and particularly provides a laboratory fuming cupboard acid waste gas treatment system which comprises a tubular heat exchanger, a washing tower, a demisting tower, a first-stage multi-medium adsorption box and a second-stage multi-medium adsorption box which are sequentially communicated through pipelines, a plurality of washing tower packing layers and a plurality of spraying units are arranged in the washing tower; a lower filler layer and an upper filler layer are also arranged in the cavity of the demisting tower; the first-stage multi-medium adsorption box is provided with a first-stage front adsorption layer and a first-stage rear adsorption layer, and the second-stage multi-medium adsorption box is internally provided with a second-stage front adsorption layer and a second-stage rear adsorption layer. The device can effectively purify the acidic waste gas of the fuming cupboard of the laboratory, meets the requirement of up-to-standard emission, and has the advantages of low power consumption, low operation cost, simplicity in operation and management and the like.

Description

Technical Field

[0001] This utility model relates to the field of acidic waste gas treatment, and in particular to an acidic waste gas treatment system for laboratory fume hoods. Background Technology

[0002] University laboratories use acidic reagents such as hydrochloric acid and hydrofluoric acid to soak fossils in fume hoods. During the soaking process, certain acidic inorganic waste gases and a small amount of organic waste gases are generated. If these waste gases are discharged directly without effective treatment, they will cause serious harm to the environment and human health. At present, the traditional treatment method mainly uses a single scrubbing tower and activated carbon adsorption. This method has low treatment efficiency and cannot remove multiple acidic gases at the same time.

[0003] Therefore, there is an urgent need for a treatment system that can effectively purify acidic exhaust gas from laboratory fume hoods, which can not only meet the emission standards but also has the advantages of low power consumption, low operating costs, and simple operation and management. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a treatment system for acidic waste gas from laboratory fume hoods, which effectively solves the problems of difficult treatment of acidic waste gas in laboratories and high operation and maintenance costs.

[0005] To achieve the above and other related objectives, this application provides a laboratory fume hood acidic waste gas treatment system. The system includes a tubular heat exchanger, a scrubbing tower, a demister, a primary multi-media adsorption box, and a secondary multi-media adsorption box, which are connected sequentially by pipes. The scrubbing tower is provided with multiple scrubbing tower packing layers and multiple spray units. The demister cavity is also provided with a lower packing layer and an upper packing layer. The primary multi-media adsorption box is provided with a primary pre-adsorption layer and a primary post-adsorption layer, and the secondary multi-media adsorption box is provided with a secondary pre-adsorption layer and a secondary post-adsorption layer.

[0006] In some embodiments of this utility model, the tubular heat exchanger includes a tubular heat exchanger inlet, a tubular heat exchanger body, and a tubular heat exchanger outlet, wherein the tubular heat exchanger outlet is connected to a scrubbing tower.

[0007] In some embodiments of this utility model, the tubular heat exchanger is a shell-and-tube heat exchanger.

[0008] In some embodiments of this utility model, a liquid collector is provided on the connecting pipeline between the tubular heat exchanger and the washing tower, a stop strip is provided inside the liquid collector, and a waste liquid collection tank is provided at the bottom of the liquid collector.

[0009] In some embodiments of this utility model, the height of the liquid-stopping strip is 10-20mm.

[0010] In some embodiments of this utility model, the scrubbing tower includes a scrubbing tower inlet and a scrubbing tower outlet, the height of which is higher than that of the scrubbing tower inlet; the scrubbing tower inlet is connected to the tubular heat exchanger, and the scrubbing tower outlet is connected to the demister.

[0011] In some embodiments of this utility model, each of the spraying units is disposed above the packing layer of the washing tower.

[0012] In some embodiments of this utility model, the demisting tower includes a demisting tower inlet and a demisting tower outlet. The height of the demisting tower outlet is higher than that of the demisting tower inlet. The demisting tower inlet is connected to the washing tower, and the demisting tower outlet is connected to the primary multi-media adsorption box.

[0013] In some embodiments of this utility model, the lower packing layer is a wire mesh, and the upper packing layer is a Pall ring.

[0014] In some embodiments of this utility model, the primary multi-media adsorption box includes a primary multi-media adsorption box inlet and a primary multi-media adsorption box outlet. The primary multi-media adsorption box inlet is connected to the demisting tower, and the primary multi-media adsorption box outlet is connected to the secondary multi-media adsorption box.

[0015] In some embodiments of this utility model, the primary pre-adsorption layer is an activated carbon layer, and the primary post-adsorption layer is an SDG adsorption layer.

[0016] In some embodiments of this utility model, the secondary multi-media adsorption box includes a secondary multi-media adsorption box inlet and a secondary multi-media adsorption box outlet. The secondary multi-media adsorption box inlet is connected to the primary multi-media adsorption box, and the secondary multi-media adsorption box outlet discharges the purified waste gas.

[0017] In some embodiments of this utility model, the secondary pre-adsorption layer is an activated carbon layer, and the secondary post-adsorption layer is an SDG adsorption layer.

[0018] Compared with the prior art, the beneficial effects of this application are as follows:

[0019] 1) This application can effectively purify acidic exhaust gas in laboratory fume hoods to meet emission standards, and has the advantages of low power consumption, low operating costs, and simple operation and management;

[0020] 2) Installing a tubular heat exchanger at the front end of the scrubbing tower can effectively solve the condensation problem in the laboratory fume hood, and prevent the hot exhaust gas from cooling down and condensing into liquid during the extraction process, causing dripping from the top of the fume hood;

[0021] 3) The packing material in the washing tower cavity is preferably a Terrary ring. Under the same throughput, the pressure drop can be reduced by 50% and the mass transfer efficiency can be increased by 40%. It has the characteristics of large throughput, low resistance, large specific surface area and high mass transfer effect. It can not only reduce the amount of alkali used, but also effectively reduce the later operating costs because its structure can withstand high mechanical loads and is not easily deformed or damaged.

[0022] 4) The primary and secondary multi-media adsorption boxes are designed for the characteristics of acidic exhaust gas in fume hoods. They use a combination of various adsorbents to not only adsorb organic matter in the exhaust gas but also purify inorganic acids. The two-stage multi-media adsorption process can achieve a purification efficiency of over 98%, which greatly improves the removal efficiency and reduces environmental risks compared to traditional treatment systems. Attached Figure Description

[0023] Figure 1 The diagram shown is a structural schematic of the laboratory fume hood acidic waste gas treatment system of this utility model.

[0024] Component designation explanation:

[0025] 1. Tubular heat exchanger

[0026] 11. Air inlet of tubular heat exchanger

[0027] 12-tube heat exchanger outlet

[0028] 13. Tubular heat exchanger body

[0029] 2. Scrubber Tower

[0030] 21. Air inlet of the scrubbing tower

[0031] 22. Scrubber tower outlet

[0032] 23. Scrubber packing layer

[0033] 24 spray units

[0034] 3. Defogging tower

[0035] 31 Demister air inlet

[0036] 32 Demister outlet

[0037] 33 Lower packing layer

[0038] 34 Upper packing layer

[0039] 4. Primary Multi-Media Adsorption Box

[0040] 41. Air inlet of the primary multi-media adsorption box

[0041] 42. Gas outlet of the primary multi-media adsorption box

[0042] 43. Primary pre-adsorption layer

[0043] 44. Primary post-adsorption layer

[0044] 5. Two-stage multi-media adsorption box

[0045] 51. Air inlet of the two-stage multi-media adsorption box

[0046] 52. Gas outlet of the two-stage multi-media adsorption box

[0047] 53 Secondary pre-adsorption layer

[0048] 54 Secondary post-adsorption layer

[0049] 6. Liquid Collector

[0050] 61. Stop strip

[0051] 7 Waste liquid collection tank

[0052] 8. Laboratory fume hood Detailed Implementation

[0053] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of this application.

[0054] The terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0057] This utility model provides a laboratory fume hood acidic waste gas treatment system for neutralizing and purifying acidic waste gas. (See reference...) Figure 1 The system includes a tubular heat exchanger 1, a scrubbing tower 2, a demister 3, a primary multi-media adsorption box 4, and a secondary multi-media adsorption box 5, which are connected in sequence by pipes.

[0058] The laboratory fume hood acidic waste gas treatment system provided in this application embodiment, such as Figure 1 The tubular heat exchanger 1 includes a tubular heat exchanger inlet 11, a tubular heat exchanger body 13, and a tubular heat exchanger outlet 12. The tubular heat exchanger outlet 12 is connected to the scrubbing tower 2, and the tubular heat exchanger inlet 11 is connected to the laboratory fume hood 8. A liquid collector 6 is installed on the connecting pipe between the tubular heat exchanger 1 and the scrubbing tower 2. The liquid collector 6 has a stop strip 61 inside, which is used to intercept and collect the condensed condensate to prevent it from being carried to the downstream treatment unit and affecting the treatment effect. There is a waste liquid collection tank 7 at the bottom of the liquid collector 6, and the liquid condensate generated after cooling flows into the waste liquid collection tank 7 by gravity. Through the above device, more than 80% of the inorganic acid in the acidic exhaust gas of the laboratory fume hood 8 can be intercepted, and even 90% of the heated acid mist in the exhaust gas can be effectively intercepted. This effectively reduces the amount of alkaline solution used in the downstream scrubbing tower 2 and the amount of SDG adsorbent filled in the multi-media adsorption box, and effectively solves the condensation problem of the laboratory fume hood 8. The preferred tube heat exchanger is a water-cooled tube heat exchanger, which uses circulating cooling water to exchange heat and cool down the acidic waste gas, thereby cooling down and condensing the hydrofluoric acid and hydrochloric acid in the waste gas at 80°C into liquid.

[0059] In some embodiments, the stop strip 61 is located at the end of the liquid collector 6 away from the tubular heat exchanger 1, and the height of the stop strip 61 is 10-20 mm, where the height refers to the height of the stop strip 61 itself.

[0060] The laboratory fume hood acidic waste gas treatment system provided in this application embodiment, such as Figure 1The scrubbing tower 2 includes a scrubbing tower inlet 21 and a scrubbing tower outlet 22. The height of the scrubbing tower outlet 22 is higher than that of the scrubbing tower inlet 21. For example, the scrubbing tower inlet 21 is located at the bottom of the scrubbing tower body, and the scrubbing tower outlet 22 is located at the top of the scrubbing tower body. The scrubbing tower inlet 21 is connected to the tubular heat exchanger 1, and further, the scrubbing tower inlet 21 is connected to the liquid collector 6. The scrubbing tower outlet 22 is connected to the demister 3. In a specific embodiment, the scrubbing tower 2 can be, for example, a cylindrical structure. The scrubbing tower 2 cavity is provided with multiple scrubbing tower packing layers 23 and multiple spray units 24, each of the spray units 24 being located above the scrubbing tower packing layers 23. The spray unit 24 is, for example, a spray head, which is used to spray a prepared sodium hydroxide alkaline solution to neutralize the acidic substances in the waste gas. The packing is used to increase the contact area between the waste gas and the sprayed alkaline solution, thereby improving the reaction efficiency. Furthermore, the packing material in the packing layer 23 of the scrubbing tower is a TerraRy ring, which can reduce the pressure drop by 50% and increase the mass transfer efficiency by 40% under the same treatment capacity. As a supplement, the scrubbing tower 2 uses an alkaline solution for spraying, with an alkaline solution concentration of 5%-20%, preferably 10%, and a spray air-to-water ratio of 8-12:1-2, preferably 10:1. The spray air-to-water ratio is the ratio of the instantaneous flow rate of the treated waste gas to the instantaneous flow rate of the spray circulating water. In a specific embodiment, the TerraRy ring is made of polypropylene, and its size can be, for example, 73 mm.

[0061] The laboratory fume hood acidic waste gas treatment system provided in this application embodiment, such as Figure 1 The demister 3 includes a demister inlet 31 and a demister outlet 32. The height of the demister outlet 32 ​​is higher than that of the demister inlet 31. For example, the demister inlet 31 is located at the bottom of the demister body, and the demister outlet 32 ​​is located at the top of the demister body. The demister inlet 31 is connected to the scrubbing tower 2, and further, the demister inlet 31 is connected to the scrubbing tower outlet 22. The demister outlet 32 ​​is connected to the primary multi-media adsorption box 4. Further, the demister 3 cavity is provided with a lower packing layer 33 and an upper packing layer 34. In a specific embodiment, the lower packing layer 33 is made of wire mesh, and the upper packing layer 34 is made of Pall rings. Both the wire mesh and the Pall rings are used to filter the water vapor generated by the scrubbing tower 2. Additionally, the wire mesh thickness is 50-150 mm, preferably 100 mm, and the Pall ring filling height is 200-600 mm, preferably 400 mm.

[0062] The laboratory fume hood acidic waste gas treatment system provided in this application embodiment, such as Figure 1The primary multi-media adsorption box 4 includes a primary multi-media adsorption box inlet 41 and a primary multi-media adsorption box outlet 42, which are respectively located on both sides of the primary activated carbon adsorption box body. The primary multi-media adsorption box inlet 41 is connected to the demister 3, and further, the primary multi-media adsorption box inlet 41 is connected to the demister outlet 32. The primary multi-media adsorption box outlet 42 is connected to the secondary multi-media adsorption box 5.

[0063] Furthermore, the primary multi-media adsorption box 4 is provided with a primary pre-adsorption layer 43 and a primary post-adsorption layer 44. In one embodiment, the primary pre-adsorption layer 43 is an activated carbon layer, used to adsorb and purify inorganic or organic substances and colloidal particles in the waste gas. In a specific embodiment, honeycomb activated carbon is selected, as it has a large specific surface area and low air resistance. The primary post-adsorption layer 44 is an SDG adsorption layer, used to adsorb and purify acidic molecules in the waste gas, mainly purifying hydrochloric acid and hydrofluoric acid. The SDG adsorption layer uses SDG adsorbent, which has a good adsorption effect on inorganic acid waste gas, with high adsorption efficiency and fast adsorption speed. The thickness of the supplementary first-stage pre-adsorption layer 43 and first-stage post-adsorption layer 44 is 300-500mm, preferably 400mm. This ensures a certain purification effect while saving equipment floor space. The empty tower velocity of the supplementary first-stage multi-media adsorption box 4 is 0.3-0.6m / s, preferably 0.4m / s. The empty tower velocity refers to the airflow velocity calculated based on the cross-sectional area of ​​the first-stage multi-media adsorption box 4 when it is unloaded. If the empty tower velocity is too high, the first-stage multi-media adsorption box 4 needs to be larger, increasing the floor space and investment. If the empty tower velocity is too low, it may affect the purification effect of the waste gas. Here, the preferred empty tower velocity is 0.4m / s, which is the most economical while ensuring a certain waste gas purification effect.

[0064] The laboratory fume hood acidic waste gas treatment system provided in this application embodiment, such as Figure 1The secondary multi-media adsorption box 5 includes a secondary multi-media adsorption box inlet 51 and a secondary multi-media adsorption box outlet 52, which are respectively located on both sides of the secondary multi-media adsorption box body. The secondary multi-media adsorption box inlet 51 is connected to the primary multi-media adsorption box 4, and further, the secondary multi-media adsorption box inlet 51 is connected to the primary multi-media adsorption box outlet 42. The secondary multi-media adsorption box outlet 52 is exposed to the air and discharges the purified waste gas. The secondary multi-media adsorption box 5 is equipped with a secondary pre-adsorption layer 53 and a secondary post-adsorption layer 54. The secondary pre-adsorption layer 53 is an activated carbon layer, preferably honeycomb activated carbon, and the secondary post-adsorption layer 54 is an SDG adsorption layer. SDG adsorbent is used to adsorb acidic molecules in the waste gas, mainly purifying hydrochloric acid and hydrofluoric acid. As a supplement, the thickness of both the secondary pre-adsorption layer 53 and the secondary post-adsorption layer 54 is 300-500mm, preferably 300mm. This ensures a certain purification effect while saving equipment floor space. As a supplement, the empty tower flow velocity of the secondary multi-media adsorption box 4 is 0.3-0.6m / s, with a preferred empty tower flow velocity of 0.6m / s, which is the most economical while ensuring a certain waste gas purification effect.

[0065] The working process of this application embodiment is as follows:

[0066] like Figure 1 The flow path of the exhaust gas is as follows: from laboratory fume hood 8 -> tubular heat exchanger 1 -> scrubbing tower 2 -> liquid collector 6 -> demister 3 -> primary multi-media adsorption box 4 -> secondary multi-media adsorption box 5 to achieve compliant discharge. Tubular heat exchanger 1 uses circulating cooling water to condense hydrofluoric acid and hydrochloric acid. Scrubbing tower 2 contains a packing layer and a spray unit, using alkaline solution for spraying to neutralize the acid in the exhaust gas. Demister 3 contains wire mesh and packing to filter the mist generated by scrubbing tower 2. Primary multi-media adsorption box 4 contains an activated carbon layer and an SDG adsorption layer to adsorb organic matter and acidic inorganic matter in the exhaust gas. Secondary multi-media adsorption box 5 also contains an activated carbon layer and an SDG adsorption layer to adsorb organic matter and acidic inorganic matter in the exhaust gas not completely purified by primary multi-media adsorption box 4.

[0067] With the above settings, this application can effectively purify the content of non-methane total hydrocarbons and inorganic acids (such as fluorides and hydrogen chloride) in the acidic exhaust gas from laboratory fume hoods, meet the emission standards, and has the advantages of low power consumption, low operating costs, and simple operation and management.

[0068] In summary, this application effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0069] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A laboratory fume hood acid exhaust treatment system, comprising: The system includes a tubular heat exchanger (1), a scrubbing tower (2), a demister (3), a primary multi-media adsorption box (4), and a secondary multi-media adsorption box (5) connected in sequence by pipes; the scrubbing tower (2) is provided with multiple scrubbing tower packing layers (23) and multiple spray units (24); the demister (3) cavity is also provided with a lower packing layer (33) and an upper packing layer (34); the primary multi-media adsorption box (4) is provided with a primary pre-adsorption layer (43) and a primary post-adsorption layer (44); the secondary multi-media adsorption box (5) is provided with a secondary pre-adsorption layer (53) and a secondary post-adsorption layer (54).

2. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, The tubular heat exchanger (1) includes a tubular heat exchanger inlet (11), a tubular heat exchanger body (13), and a tubular heat exchanger outlet (12), and the tubular heat exchanger outlet (12) is connected to the scrubbing tower (2). And / or, the tubular heat exchanger (1) is a shell-and-tube heat exchanger.

3. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, A liquid collector (6) is provided on the connecting pipeline between the tubular heat exchanger (1) and the scrubbing tower (2). A stop bar (61) is provided inside the liquid collector (6), and a waste liquid collection tank (7) is provided at the bottom of the liquid collector (6).

4. The laboratory fume hood acid exhaust treatment system of claim 3, wherein, The height of the stop strip (61) is 10-20mm.

5. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, The scrubbing tower (2) includes a scrubbing tower inlet (21) and a scrubbing tower outlet (22), the height of which is higher than that of the scrubbing tower inlet (21); the scrubbing tower inlet (21) is connected to the tubular heat exchanger (1), and the scrubbing tower outlet (22) is connected to the demister (3).

6. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, Each of the spray units (24) corresponds to each of the washing tower packing layers (23), and the spray units (24) are located above the washing tower packing layers (23).

7. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, The demisting tower (3) includes a demisting tower inlet (31) and a demisting tower outlet (32). The height of the demisting tower outlet (32) is higher than that of the demisting tower inlet (31). The demisting tower inlet (31) is connected to the washing tower (2), and the demisting tower outlet (32) is connected to the primary multi-media adsorption box (4).

8. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, The lower packing layer (33) is a wire mesh, and the upper packing layer (34) is a Pall ring.

9. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, The primary multi-media adsorption box (4) includes a primary multi-media adsorption box inlet (41) and a primary multi-media adsorption box outlet (42). The primary multi-media adsorption box inlet (41) is connected to the demisting tower (3), and the primary multi-media adsorption box outlet (42) is connected to the secondary multi-media adsorption box (5). And / or, the primary pre-adsorption layer (43) is an activated carbon layer, and the primary post-adsorption layer (44) is an SDG adsorption layer.

10. The laboratory fume hood acid exhaust treatment system of claim 1, wherein, The secondary multi-media adsorption box (5) includes a secondary multi-media adsorption box inlet (51) and a secondary multi-media adsorption box outlet (52). The secondary multi-media adsorption box inlet (51) is connected to the primary multi-media adsorption box (4), and the secondary multi-media adsorption box outlet (52) discharges the purified waste gas. And / or, the secondary pre-adsorption layer (53) is an activated carbon layer, and the secondary post-adsorption layer (54) is an SDG adsorption layer.

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