Printing tail gas treatment equipment and process

Abstract

The invention discloses printing tail gas treatment equipment and process, the printing tail gas treatment equipment comprises a support and a vacuum tank installed on the support, adsorption liquid is arranged in the vacuum tank, the vacuum tank is provided with a gas inlet pipe, a liquid outlet pipe and a gas outlet pipe, the gas inlet pipe is inserted below the liquid level of the adsorption liquid, and the liquid outlet pipe is inserted below the liquid level of the adsorption liquid. The liquid outlet pipe is connected with a sewage pump, one end of the gas outlet pipe is located on the liquid level of the adsorption liquid, the other end of the gas outlet pipe is connected into a vacuum pump, the vacuum pump is further connected with an adsorption box, and an adsorption material is arranged in the adsorption box. The printing tail gas treatment process comprises the steps that printing tail gas is conveyed into adsorption liquid of a vacuum tank, then a sewage pump and a vacuum pump are started, the adsorption liquid is sucked into the sewage pump, the printing tail gas above the adsorption liquid is conveyed into an adsorption box by the vacuum pump, and finally the printing tail gas is adsorbed by an adsorption material in the adsorption box. The printing tail gas treatment device has the beneficial effects that the printing tail gas treatment efficiency is improved, and printing tail gas can be conveniently recycled.

Description

Technical Field

[0001] The invention belongs to the technical field of waste gas treatment, and in particular relates to a printing tail gas treatment device and process. Background Art

[0002] Organic waste gas VOCs are key precursors to the formation of PM2.5 and ozone. They are physiologically toxic and pose a huge threat to the environment and human health. In recent years, the treatment of VOCs has become a key issue in the field of waste gas treatment. In the printing process of printing plants, the solvent-based inks used are composed of pigment binders, solvents, fillers and auxiliary agents. These components generally have 50% to 60% volatile components. These volatile components are directly discharged into the atmosphere as tail gas and become one of the sources of VOCs.

[0003] If the printing exhaust gas is not treated and directly discharged, it will cause huge pollution to the environment. Therefore, targeted treatment equipment is needed to treat the exhaust gas generated during the printing process. At present, the exhaust gas treatment is mainly achieved with the help of exhaust gas treatment devices. However, the overall structure of the existing exhaust gas treatment device is relatively complex, so that during the printing exhaust gas treatment process, the exhaust gas needs to flow through multiple devices in turn, resulting in low exhaust gas treatment efficiency and reduced exhaust gas recovery rate. Summary of the invention

[0004] The existing printing exhaust gas treatment device has a relatively complex overall structure, has a low printing exhaust gas treatment efficiency, and has a low recovery rate. The following invention is now proposed:

[0005] A printing exhaust gas treatment device comprises a bracket and a vacuum tank mounted on the bracket, wherein an adsorption liquid is arranged inside the vacuum tank, and an air inlet pipe, a liquid outlet pipe, and an air outlet pipe are arranged on the vacuum tank, wherein the air inlet pipe is inserted below the liquid level of the adsorption liquid, the liquid outlet pipe is connected to a sewage pump, one end of the air outlet pipe is located above the liquid level of the adsorption liquid, and the other end is connected to a vacuum pump, wherein the vacuum pump is further connected to an adsorption box, wherein an adsorption material is arranged inside the adsorption box. The printing exhaust gas enters the adsorption liquid through the air inlet pipe, partially dissolves in the adsorption liquid, and partially floats above the adsorption liquid, and after the sewage pump and the vacuum pump are started, the adsorption liquid is sucked into the sewage pump, and the printing exhaust gas located above the adsorption liquid is sucked into the adsorption box through the vacuum pump.

[0006] Furthermore, an adsorption chamber is provided in the adsorption box, and a plurality of partitions are provided in the adsorption chamber to divide the adsorption chamber into a plurality of sub-chambers, and adsorption materials are provided in each sub-chamber. After the printing exhaust gas passes through the sub-chamber, it is adsorbed by the adsorption material for multiple times to ensure that the pollutants in the printing exhaust gas are completely adsorbed.

[0007] Furthermore, the vacuum tank is provided with a discharge port and a material change port, the opening of the material change port is sealed with a cover plate, the air inlet pipe passes through the cover plate and is inserted below the liquid surface of the adsorption liquid, and the material change port is located at the bottom of the vacuum tank.

[0008] Furthermore, the sewage pump is also provided with a sewage pipe and a return pipe, the return pipe is connected to the bottom of the vacuum tank, and the adsorption liquid after passing through the sewage valve is divided into two parts, solid and liquid, wherein the solid flows out from the sewage pipe and the liquid flows into the vacuum tank from the return pipe.

[0009] Furthermore, the adsorption material is activated carbon or graphene. The graphene has a larger specific surface area and a better adsorption effect on printing exhaust gas, but the cost is relatively high.

[0010] Furthermore, the adsorption liquid is an organic solvent or a composite absorbent. Furthermore, the organic solvent includes one or more of BDO, DEHP, and DEHA; the composite absorbent includes water and a surfactant, and specifically, the surfactant is an ionic surfactant.

[0011] A printing tail gas treatment process, characterized in that it comprises the following steps:

[0012] S1. Collect the printing exhaust gas and pass it into the vacuum tank of the printing exhaust gas treatment equipment through the air inlet pipe. The printing exhaust gas enters the adsorption liquid, part of it is dissolved in the adsorption liquid, and part of it floats on the adsorption liquid;

[0013] S2, start the sewage pump and the vacuum pump, the sewage pump sucks the adsorption liquid through the liquid outlet pipe on the vacuum tank, and separates the solid and liquid phases in the adsorption liquid, wherein the solid part is discharged through the sewage outlet, and the liquid part flows back into the vacuum tank through the reflux pipe, and the vacuum pump sucks the printing exhaust gas that is not adsorbed by the adsorption liquid into the adsorption box;

[0014] S3. The adsorption material arranged in the adsorption box adsorbs and purifies the components in the printing exhaust gas. When different adsorption materials are arranged in multiple sub-chambers, the efficiency and range of the adsorption purification can be improved.

[0015] The present invention proposes a printing exhaust gas treatment device and a process for treating printing exhaust gas using the treatment device. Compared with the existing printing exhaust gas treatment equipment and process, the present invention has the following beneficial effects: a single device can complete the treatment of printing exhaust gas with high treatment efficiency, and the treated printing exhaust gas is directly separated into three states: solid, liquid and gas, which is convenient for subsequent recycling and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The three-dimensional structure diagram of the printing tail gas treatment device of the present invention is shown in FIG. Figure 1 ;

[0017] Figure 2 The three-dimensional structure diagram of the printing tail gas treatment device of the present invention is shown in FIG. Figure 2 ;

[0018] Figure 3 It is a schematic diagram of the internal structure of the adsorption box in the present invention.

[0019] The corresponding relationship between the illustrations and component names in the figure is as follows:

[0020] 1. Vacuum tank; 2. Sewage pump; 3. Vacuum pump; 4. Adsorption box; 11. Air inlet pipe; 12. Discharge port; 13. Material change port; 14. Cover plate; 15. Bracket; 21. Liquid outlet pipe; 22. Sewage outlet; 23. Reflux pipe; 31. Air outlet pipe; 41. Adsorption chamber; 42. Partition plate; 43. Sub-chamber; 44. Through hole; 45. Exhaust pipe. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be clearly and completely described below in conjunction with embodiments.

[0022] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of protection of this application.

[0023] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0024] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0025] In addition to being used to indicate a position or location relationship, some of the above terms may also be used to indicate other meanings. For example, the term "on" may also be used to indicate a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0026] like Figure 1-Figure 2As shown, it is a preferred embodiment of the present invention, a printing exhaust gas treatment device, including a bracket 15, a vacuum tank 1, a sewage pump 2, and a vacuum pump 3. The vacuum tank 1 is installed on the bracket 15. An adsorption liquid is provided inside the vacuum tank 1. A material replacement port 13 is provided on the side of the vacuum tank 1. A cover plate 14 is sealed and connected to the opening of the material replacement port 13. An air inlet pipe 11 is provided on the cover plate 14 and penetrates and is inserted under the liquid surface of the adsorption liquid. A discharge port 12, a liquid outlet pipe 21, and an air outlet pipe 31 are provided at the bottom of the vacuum tank 1. After the discharge port 12 is opened, the adsorption liquid can be directly discharged. After that, the operator can replace the adsorption liquid after opening the cover plate 14.

[0027] The liquid outlet pipe 21 is connected to the liquid inlet of the sewage pump 2, the liquid outlet of the sewage pump 2 is connected to the sewage pipe and one end of the reflux pipe 23, the other end of the reflux pipe 23 is connected to the vacuum tank 1, one end of the air outlet pipe 31 is located on the liquid surface of the adsorption liquid, and the other end is connected to the air inlet of the vacuum pump 3, the air outlet of the vacuum pump 3 is connected to the adsorption box 4, and the adsorption material is arranged in the adsorption box 4.

[0028] Furthermore, if Figure 3 As shown, the adsorption box 4 is provided with an adsorption chamber 41, and a plurality of partitions 42 are provided in the adsorption chamber 41 to divide the adsorption chamber 41 into a plurality of sub-chambers 43. Adsorption material is provided in each sub-chamber 43, and the last sub-chamber 43 is connected to an exhaust pipe 45. A through hole 44 connecting the sub-chamber 43 is also provided on the partition 42, and the adsorption material is activated carbon or graphene.

[0029] Activated carbon has a large specific surface area, rich microporous structure, fast adsorption and desorption rate and low cost. It is most widely used in the purification of printing exhaust gas. Its shortcomings are that it is difficult to regenerate, moisture has a great influence on the adsorption amount of activated carbon, and it has disadvantages such as flammability and easy pore blockage. It is mainly used to adsorb aldehyde organic matter in printing exhaust gas; the graphene has a larger specific surface area and rich pore structure, which is the basis of its good adsorption performance. Among them, graphene oxide made by peeling off graphite oxidized by concentrated sulfuric acid or strong oxidant is an important derivative of graphene. The adsorption of pollutants by graphene oxide mainly depends on its own oxygen-containing functional groups and aromatic alkyl groups, so it is mainly used to adsorb benzene organic matter in printing exhaust gas. However, the production cost of graphene or its derivatives is relatively high. Operators can choose to set corresponding adsorption materials in different chambers 43.

[0030] In actual use, the composition of the adsorption liquid needs to be determined according to other components of the printing exhaust gas. Existing adsorption liquids include organic solvents, composite absorbents, microemulsion absorbents, ionic liquid absorbents, etc. In the present invention, the adsorption liquid is an organic solvent or a composite absorbent.

[0031] Different components of the adsorption liquid will directly affect the adsorption effect on printing exhaust gas. Therefore, it is critical to select a suitable adsorption liquid according to the composition of the printing exhaust gas.

[0032] Implementation Case 1

[0033] When the adsorption liquid is an organic solvent, some oil substances with a relatively high boiling point are usually used, such as waste engine oil, lubricating oil, washing oil, biodiesel, No. 0 diesel, etc. In this embodiment, the adsorption liquid includes one or more of 1,4-butanediol (BDO), di(2-ethylhexyl) phthalate (DEHP), and dioctyl adipate (DEHA). Previous studies have shown that DEHP has a better absorption effect on alkane organic matter in printing exhaust gas, while DEHA has a better absorption effect on chlorine-containing or benzene-containing organic matter, and BDO has a moderate adsorption effect on any organic matter.

[0034] Implementation Case 2

[0035] When the composite absorbent is a composite absorbent, strictly speaking, the range of composite absorbent is relatively wide, and the specific adsorption capacity depends on the type of absorbent added. In the present embodiment, the composite absorbent includes a surfactant and water. The surfactant is a substance that contains both hydrophilic groups and hydrophobic groups in its molecules. When the surfactant in the solution phase reaches a certain concentration, it can spontaneously form non-polar micelles in the internal microenvironment, significantly increasing the solubility of insoluble or poorly soluble organic matter in the solution phase. Surfactants are divided into ionic surfactants, non-ionic surfactants, compound surfactants, other surfactants, etc. Taking ionic surfactants as an example, they include sulfonates and sulfates, etc., which can dissolve and adsorb most lipid organic compounds.

[0036] Next, the printing tail gas treatment process is established by further using the above printing tail gas treatment equipment, including the following steps:

[0037] S1. Collect the printing exhaust gas generated during the printing process and pass it into the air inlet pipe 11 of the printing exhaust gas treatment equipment. The printing exhaust gas enters the adsorption liquid, a part of it is dissolved in the adsorption liquid, and the other part floats on the adsorption liquid.

[0038] S2. Start the sewage pump 2 and the vacuum pump 3. After the sewage pump 2 is started, the liquid outlet pipe 21 of the vacuum tank 1 transports the adsorption liquid to the liquid inlet of the sewage pump 2. After the adsorption liquid passes through the sewage pump 2, the solid and liquid inside are separated from each other, wherein the solid part is discharged through the sewage outlet 22, and the liquid part flows back into the vacuum tank 1 through the reflux pipe 23; after the vacuum pump 3 is started, the printing exhaust gas floating above the adsorption liquid passes through the intake pipe 11 and is adsorbed into the intake port of the vacuum pump 3, and then transported to the adsorption box 4 through the outlet of the vacuum pump 3.

[0039] S3. When the printing exhaust gas passes through the activated carbon, the organic pollutants therein are adsorbed by the adsorption material in the adsorption box 4. Finally, the printing exhaust gas without organic pollutants is discharged from the exhaust pipe 45, and the treatment of the printing exhaust gas is completed.

[0040] After the present invention is started, the solid, liquid and gaseous organic components in the printing exhaust gas are processed and separated from each other at the same time, which improves the processing efficiency of the printing exhaust gas on the one hand, and is convenient for operators to recycle and reuse the useful components in the printing exhaust gas on the other hand.

[0041] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A printing exhaust gas treatment device, characterized in that: The invention comprises a bracket (15) and a vacuum tank (1) mounted on the bracket (15), wherein an adsorption liquid is provided inside the vacuum tank (1), and an air inlet pipe (11), a liquid outlet pipe (21), and an air outlet pipe (31) are provided on the vacuum tank (1), wherein the air inlet pipe (11) is inserted below the liquid surface of an organic solvent, the liquid outlet pipe (21) is connected to a sewage pump (2), one end of the air outlet pipe (31) is located above the liquid surface of the organic solvent, and the other end is connected to a vacuum pump (3), and the vacuum pump (3) is also connected to an adsorption box (4), wherein adsorption material is provided inside the adsorption box (4).

2. The processing device according to claim 1, characterized in that: An adsorption chamber (41) is provided in the adsorption box (4), and a plurality of partitions (42) are provided in the adsorption chamber (41) to divide the adsorption chamber (41) into a plurality of sub-chambers (43), and adsorption material is provided in each sub-chamber (43).

3. The processing device according to claim 1, characterized in that: The vacuum tank (1) is also provided with a discharge port (12) and a material change port (13); the opening of the material change port (13) is sealed with a cover plate (14); the air inlet pipe (11) passes through the cover plate (14) and is inserted below the liquid surface of the organic solvent; and the material change port (13) is located at the bottom of the vacuum tank (1).

4. The processing device according to claim 1, characterized in that: The sewage pump (2) is also provided with a sewage pipe and a return pipe (23), and the return pipe (23) is connected to the bottom of the vacuum tank (1).

5. The processing device according to claim 2, characterized in that: The adsorption material is activated carbon or graphene.

6. The processing device according to claim 1, characterized in that: The adsorption liquid is an organic solvent or a composite absorbent.

7. The processing device according to claim 6, characterized in that: The organic solvent includes one or more of BDO, DEHP and DEHA.

8. The processing device according to claim 7, characterized in that: The composite absorbent comprises water and a surfactant.

9. A printing tail gas treatment process, characterized in that: The following steps are involved: S1. Collect the printing exhaust gas and pass it into the air inlet pipe (11) of the printing exhaust gas treatment device according to any one of claims 1 to 8, so that the printing exhaust gas enters the adsorption liquid and is partially dissolved in the adsorption liquid; S2, starting the sewage pump (2) and the vacuum pump (3), wherein the sewage pump (2) sucks the adsorption liquid through the liquid outlet pipe (21) on the vacuum tank (1) and separates the solid and liquid in the adsorption liquid, and the vacuum pump (3) sucks the printing exhaust gas that is not adsorbed by the adsorption liquid into the adsorption box (4); S3, the adsorption material in the adsorption box (4) adsorbs the printing exhaust gas.

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