A foamed exhaust gas purification emission treatment system

Abstract

The utility model discloses a foaming waste gas purification discharging treatment system, including spraying tower, filter equipment, and spraying tower is equipped with outlet, upper layer spraying device, upper layer filler layer, lower layer spraying device, lower layer filler layer, gas inlet and liquid outlet from top to bottom in proper order, and the gas inlet is connected with one interface of gas inlet three -way valve, and the gas inlet three -way valve remaining two interfaces are connected with primary foaming exhaust pipe and secondary foaming exhaust pipe respectively, when the gas inlet three -way valve conduction gas inlet and primary foaming exhaust pipe, or conduction gas inlet and primary foaming exhaust pipe and secondary foaming exhaust pipe, upper layer spraying device sprays first spraying liquid to the inside of spraying tower, and lower layer spraying device sprays second spraying liquid to the inside of spraying tower, when the gas inlet three -way valve conduction gas inlet secondary foaming exhaust pipe, lower layer spraying device sprays second spraying liquid to the inside of spraying tower, solve the technical contradiction of primary foaming high -concentration waste gas treatment effect deficiency, and the serious waste of spraying liquid when treating secondary foaming low -concentration waste gas.

Description

Technical Field

[0001] This application relates to the field of foaming waste gas purification and emission treatment technology. Background Technology

[0002] In the production of foamed materials such as EPP (expanded polypropylene), the exhaust gases emitted from primary and secondary foaming processes differ significantly in composition and pollutant characteristics. Primary foaming, as a direct foaming process in the material forming stage, requires the use of physical foaming agents (such as pentanes) or chemical foaming agents. The emitted exhaust gases not only contain a large amount of unreacted foaming agent residues but also volatile organic compounds (VOCs) and high-temperature pyrolysis products, resulting in high overall pollutant concentrations and a heavy treatment load. Secondary foaming, on the other hand, involves a secondary expansion treatment of the preformed blank. The exhaust gases consist mainly of a small amount of high-temperature decomposition products and solvent residues, with low pollutant concentrations and relatively simple composition.

[0003] In existing technologies, the treatment of primary and secondary foaming waste gases generally adopts a homogeneous spraying mode, in which both types of waste gases are directly introduced into the same spray tower and treated uniformly with a fixed ratio of spray liquid. This method cannot adjust the spray intensity according to the high concentration characteristics of primary foaming waste gas to ensure purification efficiency, which easily leads to inadequate pollutant removal; it is also difficult to adapt to the low concentration characteristics of secondary foaming waste gas, resulting in excessive consumption of spray liquid and serious waste of resources. At the same time, the fixed spraying strategy cannot take into account the differentiated treatment needs of the two types of waste gases, ultimately leading to low overall system treatment efficiency and high operating costs. Utility Model Content

[0004] This utility model aims to solve at least one of the technical problems existing in the prior art. To this end, this utility model proposes: A foaming waste gas purification and emission treatment system includes a spray tower and a filter device. The spray tower is provided with an air outlet, an upper spray device, an upper packing layer, a lower spray device, a lower packing layer, an air inlet, and a liquid outlet from top to bottom. The air inlet is connected to one interface of an air inlet three-way valve, and the remaining two interfaces of the air inlet three-way valve are respectively connected to a primary foaming exhaust pipe and a secondary foaming exhaust pipe. The air inlet three-way valve can connect the air inlet to the primary foaming exhaust pipe and / or the secondary foaming exhaust pipe. When the air inlet three-way valve connects the air inlet to the primary foaming exhaust pipe, or connects the air inlet to both the primary foaming exhaust pipe and the secondary foaming exhaust pipe, the upper spraying device sprays the first spraying liquid into the spraying tower, and the lower spraying device sprays the second spraying liquid into the spraying tower. When the three-way valve of the air inlet is connected to the secondary foaming exhaust pipe of the air inlet, the lower spraying device sprays the second spray liquid into the spraying tower.

[0005] The technical solution adopted by one embodiment of this utility model to solve its technical problem is as follows: it further includes a first circulation tank and a second circulation tank, the liquid outlet is connected to the liquid inlet of the liquid outlet three-way valve, the first liquid outlet of the liquid outlet three-way valve is connected to the first filter, the first circulation tank and the upper spray device in sequence, and the second liquid outlet is connected to the second filter, the second circulation tank and the lower spray device in sequence. When the primary foaming exhaust pipe sends primary foaming waste gas into the spray tower through the air inlet three-way valve, or when both the secondary foaming exhaust pipe and the secondary foaming exhaust pipe send foaming waste gas into the spray tower through the air inlet three-way valve, the liquid outlet three-way valve connects the liquid outlet inlet to the first liquid outlet interface. When the secondary foaming exhaust pipe sends secondary foaming waste gas into the spray tower through the air inlet three-way valve, the liquid outlet three-way valve connects the liquid outlet inlet and the second liquid outlet interface.

[0006] The technical solution adopted by one embodiment of this utility model to solve its technical problem is as follows: a heater is provided in the first circulation tank, the heater is used to heat the liquid in the first circulation tank, and the top of the first circulation tank is connected to a condenser and a recovery tank in sequence.

[0007] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: both the first filter and the second filter are precision filters.

[0008] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the packing of the upper packing layer is Pall ring packing.

[0009] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the packing of the lower packing layer is a stepped ring packing.

[0010] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the filtration device is an activated carbon filter.

[0011] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: the filter device is provided in two parts, and the air outlet of the spray tower is connected to the two filter devices in sequence.

[0012] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: a demister is also provided between the air outlet and the upper spray device.

[0013] The beneficial effects of this invention are as follows: For high-concentration waste gas generated during primary foaming, a first and second spray liquid are used in synergistic spraying to enhance the absorption of primary foaming waste gas or primary and secondary mixed foaming waste gas. For low-concentration waste gas generated during secondary foaming, only the second spray liquid is used for spraying treatment, avoiding over-treatment of low-concentration secondary foaming waste gas by the high-concentration first spray liquid, and effectively reducing the overall consumption of spray liquid. This solution, through differentiated spraying of the first and second spray liquids, precisely adapts to the differences in concentration and composition between the two types of waste gas, meeting the spraying treatment needs of foaming waste gas with different concentrations and compositions. It solves the technical contradiction of insufficient treatment effect for high-concentration primary foaming waste gas and serious waste of spray liquid when treating low-concentration secondary foaming waste gas under the traditional fixed spray mode. Attached Figure Description

[0014] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the foaming waste gas purification and emission treatment system described in this embodiment; Figure 2 The spray tower described in this embodiment is equipped with an air inlet three-way valve and a liquid outlet three-way valve. Detailed Implementation

[0015] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0016] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0017] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0018] In this utility model, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0019] Reference Figure 1-2 This application proposes an embodiment of the foaming waste gas purification and emission treatment system, which includes a connected spray tower 10, a filter device 130, and an exhaust pipe 150. The spray tower 10 is provided with an air outlet 11, an upper spray device 12, an upper packing layer 13, a lower spray device 14, a lower packing layer 15, an air inlet 16, and a liquid outlet 17 from top to bottom. The air inlet 16 is connected to one interface of an air inlet three-way valve 20, and the remaining two interfaces of the air inlet three-way valve 20 are respectively connected to a primary foaming exhaust pipe 30 and a secondary foaming exhaust pipe 40. When the primary foaming exhaust pipe 30 sends primary foaming waste gas into the spray tower 10 through the air inlet three-way valve 20, or when both the primary foaming exhaust pipe 30 and the secondary foaming exhaust pipe 40 send foaming waste gas into the spray tower 10 through 20, the upper spraying device 12 sprays the first spraying liquid into the spray tower 10, and the lower spraying device 14 sprays the second spraying liquid into the spray tower 10. When the secondary foaming exhaust pipe 40 sends secondary foaming waste gas into the spray tower 10 through the air inlet three-way valve 20, the lower spraying device 14 sprays the second spray liquid into the spray tower 10.

[0020] When the intake three-way valve 20 opens the primary foaming exhaust pipe 30, or simultaneously opens the primary and secondary foaming exhaust pipes 40, the upper spray device 12 sprays the first spray liquid, and the lower spray device 14 sprays the second spray liquid, thereby achieving stratified treatment of high-concentration waste gas.

[0021] When the intake three-way valve 20 only opens the secondary foaming exhaust pipe 40, only the lower spray device 14 sprays the second spray liquid to meet the low-concentration waste gas treatment requirements.

[0022] For high-concentration waste gas from primary foaming, a first spray liquid is used, which is a high-concentration spray liquid to enhance the absorption of the waste gas. For low-concentration waste gas from secondary foaming, a low-concentration spray liquid is used to avoid over-treatment of the secondary foaming waste gas by the high-concentration spray liquid, reduce the consumption of spray liquid, and thus adapt to the compositional differences of the two types of waste gas. This method is suitable for spray treatment of waste gas with different compositions and solves the contradiction of insufficient treatment of high-concentration waste and serious waste of low-concentration waste in fixed spray mode.

[0023] The air outlet 11 is located at the top of the tower, and the air inlet 16 is located at the bottom of the tower. The air inlet three-way valve 20 is a pneumatic three-way ball valve. The spray device includes multiple spray heads. The upper spray device 12 has hollow cone spray heads evenly arranged along the circumference of the tower body, and the lower spray device 14 has spiral wide-angle spray heads.

[0024] Each of the filler layers includes a grid support plate and a clamping ring disposed above the grid support plate, with filler filling the space between the grid support plate and the clamping ring.

[0025] Preferably, the system also includes a first circulation tank 50 and a second circulation tank 60. The liquid outlet 17 is connected to the liquid outlet inlet of the liquid outlet three-way valve 70. The first liquid outlet of the liquid outlet three-way valve 70 is connected in sequence to the first filter 80, the first circulation tank 50 and the upper spray device 12, and the second liquid outlet is connected in sequence to the second filter 90, the second circulation tank 60 and the lower spray device 14. When the primary foaming exhaust pipe 30 sends primary foaming waste gas into the spray tower 10 through the air inlet three-way valve 20, or when both the primary foaming exhaust pipe 30 and the secondary foaming exhaust pipe 40 send foaming waste gas into the spray tower 10 through the air inlet three-way valve 20, the liquid outlet three-way valve 70 connects the liquid outlet inlet with the first liquid outlet interface. When the secondary foaming exhaust pipe 40 sends secondary foaming waste gas into the spray tower 10 through the air inlet three-way valve 20, the liquid outlet three-way valve 70 connects the liquid outlet inlet and the second liquid outlet interface.

[0026] The liquid outlet three-way valve 70 is an electric three-way ball valve, and its liquid outlet inlet is connected to the liquid outlet 17 of the spray tower 10. Centrifugal pumps are respectively installed between the first filter 80 and the first circulation tank 50, between the first circulation tank 50 and the upper spray device 12, between the second filter 90 and the second circulation tank 60, and between the second circulation tank 60 and the lower spray device 14.

[0027] The inlet three-way valve 20 and the outlet three-way valve 70 are both connected to the electrical control systems of the primary foaming kettle and the secondary foaming kettle. Each of the primary and secondary foaming kettles is equipped with an exhaust valve, and their electrical control systems are electrically connected to the corresponding exhaust valves. The inlet three-way valve 20 and the outlet three-way valve 70 control their conduction states based on whether the exhaust valves on the primary and secondary foaming kettles are currently open. For example, when both exhaust valves on the primary and secondary foaming kettles are open, the inlet three-way valve 20 connects the inlet 16 to the primary foaming exhaust pipe 30 and the secondary foaming exhaust pipe 40; when the exhaust valve on the primary foaming kettle is closed and the exhaust valve on the secondary foaming kettle is open, the inlet three-way valve 20 connects the inlet 16 to the secondary foaming exhaust pipe 40.

[0028] When treating primary foaming waste gas or mixed waste gas, the liquid outlet three-way valve 70 connects the liquid outlet 17 of the spray tower 10 with the first circulation tank 50. The spray liquid containing high concentration of pollutants is removed by the first filter 80 and then sent to the upper spray device 12 for circulation by the first transfer pump. When treating secondary foaming waste gas, the liquid outlet three-way valve 70 connects the liquid outlet 17 of the spray tower 10 with the second circulation tank 60. The low-pollution spray liquid is filtered by the second filter 90 and then pumped to the lower spray device 14 for circulation.

[0029] The upper spray device 12, the first circulation tank 50, and the first filter 80 form an independent circulation, and the lower spray device 14, the second circulation tank 60, and the second filter 90 form an independent circulation. The treatment system has two independent circulations. The high-concentration spray liquid contains foaming agent residue, VOCs, etc., while the low-concentration spray liquid contains a small amount of solvent residue. The filter media of the first filter 80 and the second filter 90 are designed according to the composition of different spray liquids, so as to achieve separate treatment of different spray liquids and reduce the energy consumption of low-concentration spray liquid circulation.

[0030] Preferably, the first circulation tank 50 is provided with a heater 100, which is used to heat the liquid in the first circulation tank 50. The top of the first circulation tank 50 is connected to a condenser 110 and a recovery tank 120 in sequence.

[0031] Specifically, a coil heater 100 is installed inside the first circulation tank 50. The stainless steel coil heater 100 is equipped with a temperature controller, and the heating medium is heat transfer oil. A steam outlet is provided at the top of the first circulation tank 50, which is connected in sequence to a shell-and-tube condenser 110 and a sealed recovery tank 120. The heater 100 heats the high-concentration spray liquid in the first circulation tank 50 to 40-45°C, causing the dissolved foaming agent, such as pentane and VOCs, to volatilize into steam. The steam is condensed into liquid by the condenser 110 and collected in the recovery tank 120. The regenerated spray liquid is returned to the upper spray device 12 for recycling, thereby efficiently recovering the foaming agent in the primary foaming waste gas. The recovered product can be reused in the foaming process, reducing raw material costs.

[0032] Solid impurities such as polymer debris and dust in the spray liquid are trapped as they flow through the filter element, allowing only clean liquid to pass through and enter the circulation pipeline, ensuring that the spray head channels are not blocked. Both the first filter 80 and the second filter 90 use PP pleated filter elements with a filtration accuracy of 5μm. Pressure gauges are installed at the inlet and outlet of the filters. When the pressure difference is ≥0.2MPa, an audible and visual alarm is triggered, prompting the replacement of the filter element. A drain port is provided at the bottom of the filter for easy backwashing and impurity removal.

[0033] In this embodiment, the upper packing layer uses Pall ring packing, which has good liquid dispersibility and can make the spray liquid form a uniform liquid film on the surface of the packing, fully contacting the upward foaming waste gas, and removing low-concentration pollutants through physical adsorption and chemical absorption; the lower packing layer uses stepped ring packing, whose high porosity allows high-flow spray liquid to pass through, fully contacting the high-concentration waste gas of the first foaming, and quickly absorbing pollutants in the gas phase.

[0034] Preferably, the filtration device 130 is an activated carbon filter. The exhaust gas treated by the spray tower 10 enters the activated carbon filter, where the activated carbon captures residual trace VOCs and foaming agents through physical adsorption, further purifying the exhaust gas and ensuring that the purified exhaust gas meets emission standards.

[0035] Preferably, two filtration devices 130 are provided, and the air outlet 11 of the spray tower 10 is connected to the two filtration devices 130 in sequence. Under normal operating conditions, the exhaust gas passes through the two filters in sequence. When one filter becomes saturated, the system switches to single-unit operation so that the other unit continues to process the gas, allowing the saturated filter to be replaced with activated carbon offline.

[0036] In this embodiment, a demister 140 is also provided between the air outlet 11 and the upper spray device 12. The demister 140 is a two-stage combined structure, with a PP corrugated plate demister as the first stage and a glass fiber felt demister as the second stage. When the mist droplets in the exhaust gas pass through the corrugated plate demister, they are intercepted by the plate wall due to inertial collision; the remaining tiny mist droplets are captured by the fiber felt demister, achieving complete gas-liquid separation. This prevents the spray liquid from being lost with the exhaust gas, reduces the absorbent loss rate, and prevents mist droplets from entering the activated carbon layer and causing it to become damp and ineffective, thus helping to extend the activated carbon replacement cycle.

[0037] Of course, this utility model is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of this utility model. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. A foaming waste gas purification and emission treatment system, characterized in that, The system includes a spray tower (10) and a filter device (130). The spray tower (10) is provided with an air outlet (11), an upper spray device (12), an upper packing layer (13), a lower spray device (14), a lower packing layer (15), an air inlet (16), and a liquid outlet (17) from top to bottom. The air inlet (16) is connected to one interface of an air inlet three-way valve (20). The remaining two interfaces of the air inlet three-way valve (20) are connected to the primary foaming exhaust pipe (30) and the secondary foaming exhaust pipe (40), respectively. The air inlet three-way valve (20) can connect the air inlet (16) to the primary foaming exhaust pipe (30) and / or the secondary foaming exhaust pipe (40). When the air inlet three-way valve (20) connects the air inlet (16) to the primary foaming exhaust pipe (30), or connects the air inlet (16) to the primary foaming exhaust pipe (30) and the secondary foaming exhaust pipe (40), the upper spraying device (12) sprays the first spraying liquid into the spraying tower (10), and the lower spraying device (14) sprays the second spraying liquid into the spraying tower (10); When the inlet three-way valve (20) opens the secondary foaming exhaust pipe (40) of the inlet (16), the lower spraying device (14) sprays the second spray liquid into the spraying tower (10).

2. The foaming waste gas purification and emission treatment system according to claim 1, characterized in that, It also includes a first circulation tank (50) and a second circulation tank (60). The liquid outlet (17) is connected to the liquid outlet inlet of the liquid outlet three-way valve (70). The first liquid outlet of the liquid outlet three-way valve (70) is connected to the first filter (80), the first circulation tank (50) and the upper spray device (12) in sequence. The second liquid outlet is connected to the second filter (90), the second circulation tank (60) and the lower spray device (14) in sequence. When the primary foaming exhaust pipe (30) sends primary foaming waste gas into the spray tower (10) through the air inlet three-way valve (20), or when both the secondary foaming exhaust pipe (40) and the secondary foaming exhaust pipe (40) send foaming waste gas into the spray tower (10) through the air inlet three-way valve (20), the liquid outlet three-way valve (70) connects the liquid outlet inlet with the first liquid outlet interface; When the secondary foaming exhaust pipe (40) sends secondary foaming waste gas into the spray tower (10) through the air inlet three-way valve (20), the liquid outlet three-way valve (70) connects the liquid outlet inlet and the second liquid outlet interface.

3. The foaming waste gas purification and emission treatment system according to claim 2, characterized in that, The first circulation tank (50) is equipped with a heater (100) for heating the liquid in the first circulation tank (50). The top of the first circulation tank (50) is connected to a condenser (110) and a recovery tank (120) in sequence.

4. The foaming waste gas purification and emission treatment system according to claim 2, characterized in that, Both the first filter (80) and the second filter (90) are precision filters.

5. The foaming waste gas purification and emission treatment system according to claim 1, characterized in that, The upper packing layer (13) is filled with Pall ring packing.

6. The foaming waste gas purification and emission treatment system according to claim 1, characterized in that, The lower packing layer (15) is filled with stepped ring packing.

7. The foaming waste gas purification and emission treatment system according to claim 1, characterized in that, The filtration device (130) is an activated carbon filter.

8. The foaming waste gas purification and emission treatment system according to claim 7, characterized in that, The filter device (130) is provided in two parts, and the air outlet (11) of the spray tower (10) is connected to the two filter devices (130) in sequence.

9. The foaming waste gas purification and emission treatment system according to claim 1, characterized in that, A demister (140) is also provided between the air outlet (11) and the upper spray device (12).

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