阅读说明：本技术 一种处理含甲醛气体的吸收与催化氧化装置 (Absorption and catalytic oxidation device for treating formaldehyde-containing gas ) 是由 庞程凯 刘飞 丁浩然 刘春红 祁志福 高强生 孙士恩 杨扬 于 2021-08-30 设计创作，主要内容包括：本发明涉及一种处理含甲醛气体的吸收与催化氧化装置,包括：滤网、引风机、引流通道、吸收液储槽、吸收液雾化器、气液分离器、除沫器、吸收液收集器、导流管、催化氧化反应器、吸收液回流泵和液位平衡管；引流通道进口设有混合气入口,引流通道内依次设有滤网、引风机和导流叶片；引流通道出口连接气液分离器进口；滤网为多级滤网；引流通道下方设有吸收液储槽,吸收液储槽内设有吸收液雾化器。本发明的有益效果是：本发明设有叶片式导流结构和吸收液雾化器,极大提高了气液接触面积,提高甲醛吸收速率；催化剂填充层设有甲醛氧化催化剂,促进吸收了的甲醛氧化分解,从根本上解决甲醛排放问题；采用多级结构除沫,确保装置零污染物排放。(The invention relates to an absorption and catalytic oxidation device for treating formaldehyde-containing gas, which comprises: the device comprises a filter screen, an induced draft fan, a drainage channel, an absorption liquid storage tank, an absorption liquid atomizer, a gas-liquid separator, a demister, an absorption liquid collector, a flow guide pipe, a catalytic oxidation reactor, an absorption liquid reflux pump and a liquid level balance pipe; the inlet of the drainage channel is provided with a mixed gas inlet, and the drainage channel is internally provided with a filter screen, a draught fan and a guide vane in sequence; the outlet of the drainage channel is connected with the inlet of the gas-liquid separator; the filter screen is a multi-stage filter screen; an absorption liquid storage tank is arranged below the drainage channel, and an absorption liquid atomizer is arranged in the absorption liquid storage tank. The invention has the beneficial effects that: the invention is provided with the vane type flow guide structure and the absorption liquid atomizer, thereby greatly improving the gas-liquid contact area and the formaldehyde absorption rate; the catalyst filling layer is provided with a formaldehyde oxidation catalyst, so that the absorbed formaldehyde is promoted to be oxidized and decomposed, and the problem of formaldehyde emission is fundamentally solved; and a multi-stage structure is adopted for defoaming, so that zero pollutant emission of the device is ensured.)

1. An absorption and catalytic oxidation apparatus for treating formaldehyde-containing gas, comprising: the device comprises a filter screen (2), an induced draft fan (3), a drainage channel (4), an absorption liquid storage tank (6), an absorption liquid atomizer (7), a gas-liquid separator (8), a demister (9), an absorption liquid collector (11), a guide pipe (12), a catalytic oxidation reactor (13), an absorption liquid reflux pump (16) and a liquid level balance pipe (17);

a mixed gas inlet (1) is arranged at the inlet of the drainage channel (4), and a filter screen (2), an induced draft fan (3) and a guide vane (5) are sequentially arranged in the drainage channel (4); the outlet of the drainage channel (4) is connected with the inlet of the gas-liquid separator (8); the filter screen (2) is a multi-stage filter screen;

an absorption liquid storage tank (6) is arranged below the drainage channel (4), and an absorption liquid atomizer (7) is arranged in the absorption liquid storage tank (6); a liquid level balance pipe (17) is arranged on the absorption liquid storage tank (6); the liquid level balance pipe (17) is connected with the catalytic oxidation reactor (13); the inlet of the absorption liquid reflux pump (16) is connected with the absorption liquid outlet of the catalytic oxidation reactor (13), and the outlet of the absorption liquid reflux pump (16) is connected with the absorption liquid storage tank (6); a catalyst filling layer (14) is arranged inside the catalytic oxidation reactor (13), an absorption liquid adding port (15) and an absorption liquid outlet are also arranged on the catalytic oxidation reactor (13), and an inlet of the catalytic oxidation reactor (13) is connected with the absorption liquid collector (11) through a guide pipe (12);

a gas-liquid separator (8) is arranged at the upper part of the absorption liquid collector (11), and a baffle plate is additionally arranged at the inlet of the gas-liquid separator (8); the upper part of the gas-liquid separator (8) is provided with a demister (9), and the top of the demister (9) is provided with a mixed gas outlet (10).

2. The absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 1, wherein: the installation position of the filter screen (2) is behind the mixed gas inlet (1); the installation positions of the draught fan (3) are arranged on two horizontal inner walls in the rear drainage channel (4) of the filter screen (2); the installation position of the guide vane (5) is on the inner wall of the rear guide channel (4) of the draught fan (3); the installation position of the absorption liquid atomizer (7) is behind the induced draft fan (3) in the horizontal direction and below the induced draft channel (4) in the vertical direction, and the specific installation position of the absorption liquid atomizer (7) is in the absorption liquid storage tank (6).

3. The absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 1, wherein: the filter screen (2) is made of nylon, plastic or stainless steel; the drainage channel (4) is cylindrical, square or coiled pipe surrounding; the guide vanes (5) are straight type, twisted vane type and opposite impact type; the angle of the twisted blade type guide vane is 10-60 degrees.

4. The absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 1, wherein: the gas-liquid separator (8) is of an upward-shrinkage downward-type structure.

5. The absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 1, wherein: the absorption liquid adding port (15) is arranged at the side edge of the catalytic oxidation reactor (13), and the absorption liquid outlet is arranged at the bottom of the catalytic oxidation reactor (13); the catalytic oxidation reactor (13) is a honeycomb, plate or corrugated reactor; the arrangement mode of the catalyst filling layer (14) in the catalytic oxidation reactor (13) is a grid type or a flat plate open pore type.

6. The absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 1, wherein: the demister (9) is one or a mixture of a silk screen, a cone, a grid type, a flat plate type, a corrugated plate type and a bag type in structure; the demister (9) is also loaded with an adsorption material which is active carbon and silica gel.

7. The absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 1, wherein: the absorption liquid collector (11) is of a necking structure, and the necking structure refers to a structure with a side wall in a certain angle.

8. An operating method of an absorption and catalytic oxidation apparatus for treating formaldehyde-containing gas as claimed in claim 1, comprising the steps of:

step 1, enabling mixed gas containing formaldehyde to enter a drainage channel (4) from a mixed gas inlet (1) and pass through a filter screen (2) under the action of a draught fan (3);

step 2, atomizing the absorption liquid stored in the absorption liquid storage tank (6) into fine droplets through an absorption liquid atomizer (7), and mixing the atomized droplets with the mixed gas containing formaldehyde in the drainage channel (4);

step 3, absorbing liquid after absorbing formaldehyde is collected by an absorbing liquid collector (11) and enters a catalytic oxidation reactor (13) through a guide pipe (12), mixed gas is discharged from an absorbing liquid outlet at the bottom of the catalytic oxidation reactor (13) after being subjected to catalytic oxidation through a catalyst filling layer (14) in the catalytic oxidation reactor (13), and is returned to an absorbing liquid storage tank (6) through an absorbing liquid reflux pump (16) for recycling;

and 4, discharging the residual mixed gas containing the formaldehyde in the drainage channel (4) from a mixed gas outlet (10) after sequentially passing through a gas-liquid separator (8) and a demister (9).

9. The operating method of an absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 8, wherein: in the step 1, the gas flow of the induced draft fan (3) is 50-500 m³(ii)/hr; the power of the absorption liquid atomizer (7) is 50-250W; in the step 3, the catalytic oxidation reactor (13) is prepared by adopting an impregnation method, or is densely packed by adopting a formed rod-shaped catalyst.

10. The operating method of an absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas as set forth in claim 8, wherein: the size of the atomized fine liquid drops in the step 2 is 1-20 mu m; in the step 3, the oxidant of the catalyst filling layer (14) in the catalytic oxidation reactor (13) is at least one of silicon oxide, aluminum oxide, activated carbon, manganese oxide, iron oxide, cerium oxide, copper oxide, nickel oxide, aluminum oxide loaded by silver and aluminum oxide loaded by platinum; in the step 3, the absorption liquid in the absorption liquid storage tank (6) is at least one of water, a sodium chlorite solution, a sodium hypochlorite solution, a potassium dichromate solution, a hydrogen peroxide solution and a potassium permanganate solution, and the mass percentage of the absorbent in the absorption liquid is 0.001-0.1%.

Technical Field

The invention belongs to the technical field of pollutant treatment, and particularly belongs to an absorption and catalytic oxidation device for treating formaldehyde-containing gas.

Background

Formaldehyde is an organic chemical substance, is colorless and irritant gas, has an irritant effect on human eyes, noses and the like, and has a toxic effect on cardiovascular systems, endocrine systems, digestive systems, reproductive systems and kidneys after being exposed to formaldehyde for a long time. In 2017, 10 and 27, the world health organization international agency for research on cancer has listed formaldehyde as a carcinogen. In 2019, 7 and 23, formaldehyde is listed in the list of toxic and harmful water pollutants (first batch).

Formaldehyde is generated in many industrial processes, such as paints, plates, wallpaper and the like, and formaldehyde is released when the formaldehyde is used for indoor decoration, and formaldehyde is also released when fuel and tobacco leaves are incompletely combusted. The specification of indoor air quality standard (GB/T18883-2002) implemented in China to formaldehyde is that the average value of 1 hour is less than or equal to 0.10mg/m³. The treatment of formaldehyde-containing gases is vital to the protection of human physical and mental health.

In the prior art, a container-type device is mostly adopted for absorbing formaldehyde, the gas mobility is poor, and the formaldehyde absorption rate is low. CN 112443912 a discloses the use of a baffle and a rotary formaldehyde remover to prolong the contact time of air with the formaldehyde remover. However, the contact area between formaldehyde in the air and the removing device is small, and the rotating device consumes extra power, so that the rotating device is prone to failure after long-term operation. CN 112370948A discloses absorbing formaldehyde by bubbling in a formaldehyde absorbing liquid through an air inlet mechanism, and releasing formaldehyde by heating. But formaldehyde is not treated fundamentally and the aqueous formaldehyde solution is still a toxic and harmful pollutant.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide an absorption and catalytic oxidation device for treating formaldehyde-containing gas.

The absorption and catalytic oxidation device for treating formaldehyde-containing gas comprises: the device comprises a filter screen, an induced draft fan, a drainage channel, an absorption liquid storage tank, an absorption liquid atomizer, a gas-liquid separator, a demister, an absorption liquid collector, a flow guide pipe, a catalytic oxidation reactor, an absorption liquid reflux pump and a liquid level balance pipe; the inlet of the drainage channel is provided with a mixed gas inlet, and the drainage channel is internally provided with a filter screen, a draught fan and a guide vane in sequence; the outlet of the drainage channel is connected with the inlet of the gas-liquid separator; the filter screen is a multi-stage filter screen; an absorption liquid storage tank is arranged below the drainage channel, and an absorption liquid atomizer is arranged in the absorption liquid storage tank; a liquid level balance pipe is arranged on the absorption liquid storage tank; the liquid level balance pipe is connected with the catalytic oxidation reactor, is used for maintaining the liquid level in the catalytic oxidation reactor and the absorption liquid collector, and is arranged for rapidly balancing the liquid level so as to avoid the over-low liquid level in the catalytic oxidation reactor and the absorption liquid collector under certain extreme working conditions; the inlet of the absorption liquid reflux pump is connected with the absorption liquid outlet of the catalytic oxidation reactor, and the outlet of the absorption liquid reflux pump is connected with the absorption liquid storage tank; a catalyst filling layer is arranged in the catalytic oxidation reactor, an absorption liquid adding port and an absorption liquid outlet are also arranged on the catalytic oxidation reactor, the catalyst filling layer is used for loading a catalyst for the formaldehyde oxidation reaction, and the absorption liquid adding port is used for periodically adding the absorption liquid; the inlet of the catalytic oxidation reactor is connected with an absorption liquid collector through a guide pipe; the upper part of the absorption liquid collector is provided with a gas-liquid separator, and a baffle plate is additionally arranged at the inlet of the gas-liquid separator and is used for quickly separating liquid drops; the upper part of the gas-liquid separator is provided with a demister, and the top of the demister is provided with a mixed gas outlet.

Preferably, the mounting position of the filter screen is behind the mixed gas inlet; the installation position of the induced draft fan is on two horizontal inner walls in the drainage channel behind the filter screen; the installation position of the guide vane is on the inner wall of the rear guide channel of the induced draft fan; the installation position of the absorption liquid atomizer is horizontally positioned behind the induced draft fan and vertically positioned below the drainage channel, and the specific installation position of the absorption liquid atomizer is in the absorption liquid storage tank; the arrangement enables the absorption liquid atomizer to generate absorption liquid drops which enter the drainage channel to be mixed with the formaldehyde-containing air under the action of negative pressure.

Preferably, the filter screen is made of nylon, plastic or stainless steel and is used for removing solid foreign matters; the drainage channel is cylindrical, square or coiled pipe surrounding; the coil pipe has the best surrounding effect, but the structure is complex; secondly, the shape of a cylinder; the flow guide channel is used for fully contacting gas with atomized absorbent liquid drops; the drainage channel of the present invention is preferably cylindrical; the guide vanes are straight type, twisted vane type and opposite impact type guide vanes, wherein the twisted vane type guide vanes have the best guide effect; the angle of the twisted blade type guide vane is 10-60 degrees.

Preferably, the gas-liquid separator has a downward-withdrawing type structure, and the gas-liquid separator separates the absorbing liquid droplets having absorbed formaldehyde and the purified gas.

Preferably, the absorption liquid adding port is arranged at the side edge of the catalytic oxidation reactor, and the absorption liquid outlet is arranged at the bottom of the catalytic oxidation reactor; the catalytic oxidation reactor is a honeycomb, plate or corrugated reactor; the arrangement mode of the catalyst filling layer in the catalytic oxidation reactor is a grid type or a flat plate open pore type.

Preferably, the demister is one or a mixture of a wire mesh, a cone, a grid, a flat plate, a corrugated plate and a bag in structure; the demister is also loaded with an adsorption material, and the adsorption material is active carbon, silica gel and the like.

Preferably, the absorption liquid collector is of a necking structure, and the necking structure refers to a structure with a side wall at a certain angle so as to facilitate the liquid drops to flow downwards; the absorption liquid collector is used for converging the absorption liquid drops and simultaneously maintaining a certain liquid level, thereby playing a role of liquid seal.

The working method of the absorption and catalytic oxidation device for treating the formaldehyde-containing gas comprises the following steps:

step 1, allowing mixed gas containing formaldehyde to enter a drainage channel from a mixed gas inlet and pass through a filter screen under the action of a draught fan;

step 2, atomizing the absorption liquid stored in the absorption liquid storage tank into fine liquid drops through an absorption liquid atomizer, and mixing the atomized liquid drops with the mixed gas containing formaldehyde in the drainage channel;

step 3, collecting the absorption liquid after absorbing the formaldehyde by an absorption liquid collector, then feeding the absorption liquid into a catalytic oxidation reactor through a guide pipe, discharging the mixed gas from an absorption liquid outlet at the bottom of the catalytic oxidation reactor after the mixed gas is subjected to catalytic oxidation through a catalyst filling layer in the catalytic oxidation reactor, and returning the mixed gas to an absorption liquid storage tank through an absorption liquid reflux pump for recycling;

and 4, discharging the residual mixed gas containing the formaldehyde in the drainage channel from the mixed gas outlet after sequentially passing through the gas-liquid separator and the demister.

Preferably, the gas flow of the induced draft fan in the step 1 is 50-500 m³(ii)/hr; the power of the absorption liquid atomizer is 50-250W; in the step 3, the catalytic oxidation reactor is prepared by adopting an impregnation method, or is densely packed by adopting a formed rod-shaped catalyst.

Preferably, the size of the atomized fine liquid drops in the step 2 is 1-20 μm; in the step 3, the oxidant of the catalyst filling layer in the catalytic oxidation reactor is at least one of silicon oxide, aluminum oxide, activated carbon, manganese oxide, iron oxide, cerium oxide, copper oxide, nickel oxide, silver-loaded aluminum oxide and platinum-loaded aluminum oxide; the absorption liquid in the absorption liquid storage tank in the step 3 is at least one of water, a sodium chlorite solution, a sodium hypochlorite solution, a potassium dichromate solution, a hydrogen peroxide solution and a potassium permanganate solution, and the mass percentage of the absorbent in the absorption liquid is 0.001-0.1%.

The invention has the beneficial effects that: the invention is provided with the vane type flow guide structure and the absorption liquid atomizer, thereby greatly improving the gas-liquid contact area and the formaldehyde absorption rate; the catalyst filling layer is provided with a formaldehyde oxidation catalyst, so that the absorbed formaldehyde is promoted to be oxidized and decomposed, and the problem of formaldehyde emission is fundamentally solved; and a multi-stage structure is adopted for defoaming, so that zero pollutant emission of the device is ensured.

Drawings

FIG. 1 is a schematic view of an absorption and catalytic oxidation apparatus for treating a formaldehyde-containing gas according to the present invention;

FIG. 2 is a side view of the installation of twisted vane type guide vanes in the drainage passage;

FIG. 3 is an elevation view of the twisted blade type guide vane in the drainage passage;

FIG. 4 is a schematic structural view of a single guide vane;

fig. 5 is a rendering view of the surface of the twisted blade type guide vane 3 d.

Description of reference numerals: the device comprises a mixed gas inlet 1, a filter screen 2, an induced draft fan 3, a drainage channel 4, a guide vane 5, an absorption liquid storage tank 6, an atomizer 7, a gas-liquid separator 8, a demister 9, a mixed gas outlet 10, a collector 11, a guide pipe 12, a catalytic oxidation reactor 13, a catalyst filling layer 14, an absorption liquid adding port 15, an absorption liquid reflux pump 16 and a liquid level balance pipe 17.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for a person skilled in the art, several modifications can be made to the invention without departing from the principle of the invention, and these modifications and modifications also fall within the protection scope of the claims of the present invention.

The atomized absorption liquid droplets and formaldehyde in the air are fully mixed in the drainage channel provided with the guide vanes, so that the gas-liquid contact area is greatly increased, and the formaldehyde absorption efficiency is favorably improved; the formaldehyde is decomposed by combining with a formaldehyde oxidation reaction catalyst, so that formaldehyde pollutants are fundamentally removed; meanwhile, the device disclosed by the invention is combined with a multi-stage defoaming structure, so that zero pollutant discharge is ensured. The invention overcomes the problems of low absorption efficiency, long treatment time, failure in fundamentally removing formaldehyde pollutants and the like caused by small contact surface between gas-phase formaldehyde and an absorption device in the prior art.

Example one

The first embodiment of the present application provides an absorption and catalytic oxidation apparatus for treating formaldehyde-containing gas as shown in fig. 1, which specifically includes:

the device comprises a filter screen 2, an induced draft fan 3, a drainage channel 4, an absorption liquid storage tank 6, an absorption liquid atomizer 7, a gas-liquid separator 8, a demister 9, an absorption liquid collector 11, a draft tube 12, a catalytic oxidation reactor 13, an absorption liquid reflux pump 16 and a liquid level balance tube 17;

the inlet of the drainage channel 4 is provided with a mixed gas inlet 1, and the drainage channel 4 is internally provided with a filter screen 2, an induced draft fan 3 and a guide vane 5 in sequence; the outlet of the drainage channel 4 is connected with the inlet of the gas-liquid separator 8; the filter screen 2 is a multi-stage filter screen;

an absorption liquid storage tank 6 is arranged below the drainage channel 4, and an absorption liquid atomizer 7 is arranged in the absorption liquid storage tank 6; a liquid level balance pipe 17 is arranged on the absorption liquid storage tank 6; the liquid level balance pipe 17 is connected with the catalytic oxidation reactor 13, is used for maintaining the liquid level in the catalytic oxidation reactor and the absorption liquid collector, is arranged for rapidly balancing the liquid level, and avoids the over-low liquid level in the catalytic oxidation reactor and the absorption liquid collector under certain extreme working conditions; the inlet of the absorption liquid reflux pump 16 is connected with the absorption liquid outlet of the catalytic oxidation reactor 13, and the outlet of the absorption liquid reflux pump 16 is connected with the absorption liquid storage tank 6; a catalyst filling layer 14 is arranged in the catalytic oxidation reactor 13, an absorption liquid adding port 15 and an absorption liquid outlet are also arranged on the catalytic oxidation reactor 13, the catalyst filling layer is used for loading a catalyst for formaldehyde oxidation reaction, and the absorption liquid adding port is used for periodically adding absorption liquid; the inlet of the catalytic oxidation reactor 13 is connected with the absorption liquid collector 11 through the draft tube 12;

the upper part of the absorption liquid collector 11 is provided with a gas-liquid separator 8, and a baffle plate is additionally arranged at the inlet of the gas-liquid separator 8 and is used for quickly separating liquid drops; the upper part of the gas-liquid separator 8 is provided with a demister 9, and the top of the demister 9 is provided with a mixed gas outlet 10.

The installation position of the filter screen 2 is behind the mixed gas inlet 1; the installation position of the draught fan 3 is on two horizontal inner walls in the drainage channel 4 behind the filter screen 2; the installation position of the guide vane 5 is on the inner wall of the rear guide channel 4 of the induced draft fan 3; the installation position of the absorption liquid atomizer 7 is horizontally behind the induced draft fan 3 and vertically below the drainage channel 4, and the specific installation position of the absorption liquid atomizer 7 is in the absorption liquid storage tank 6; the arrangement enables the absorption liquid atomizer to generate absorption liquid drops which enter the drainage channel to be mixed with the formaldehyde-containing air under the action of negative pressure.

The filter screen 2 is made of nylon, plastic or stainless steel; the drainage channel 4 is cylindrical, square or coiled pipe surrounding shape; as shown in fig. 2 to 4, the guide vane 5 is a straight type, a twisted vane type, or a facing type; the angle of the twisted blade type guide vane is 10-60 degrees.

Example two

On the basis of the first embodiment, the second embodiment of the present application provides a working method of the absorption and catalytic oxidation apparatus for treating formaldehyde-containing gas in the first embodiment:

the temperature is 25 ℃, the catalyst is a mixture of 30 wt% manganese oxide and 70 wt% diatomite, the absorption liquid is sodium hypochlorite solution with the mass concentration of 0.01%, and the instrument is placed in a volume of 1m³Formaldehyde concentration 1mg/m³In a closed plexiglass container, the formaldehyde concentration drops to 0.08mg/m after 17 minutes from the operation of the apparatus³After the instrument runs for 32 minutes, the concentration of formaldehyde is reduced to 0.01mg/m³。

EXAMPLE III

On the basis of the first embodiment, the third embodiment of the present application provides a working method of the absorption and catalytic oxidation apparatus for treating formaldehyde-containing gas in the first embodiment:

at the temperature of 25 ℃, the catalyst is an oxide mixture of 30 wt% of manganese oxide, 30 wt% of cerium oxide and 40 wt% of diatomite, the absorption liquid is a mixed solution of sodium chlorite and 0.01% of potassium permanganate with the mass concentration of 0.05%, and the instrument is placed in a volume of 1m³Formaldehyde concentration 0.5mg/m³In a sealed organic glass container, the formaldehyde concentration is reduced to 0.08mg/m after the instrument runs for 14 minutes³After the instrument runs for 28 minutes, the concentration of formaldehyde is reduced to 0.01mg/m³。