CN110368777A - Formaldehyde absorbing device - Google Patents

Abstract

The invention relates to the technical field of gas adsorption, and discloses a formaldehyde adsorption device, comprising at least two activated carbon beds for adsorbing or desorbing formaldehyde, an air compressor for sucking formaldehyde-containing air from a formaldehyde environment space and feeding it into the activated carbon beds, adjacent to A throttle valve is installed between the activated carbon beds, and the connecting pipe between each end of the throttle valve and the activated carbon bed is connected with an exhaust pipe. After being compressed, the formaldehyde-containing air is sent to one or more activated carbon beds through a solenoid valve for Formaldehyde adsorption, part of the air from the activated carbon bed for formaldehyde adsorption is discharged through the exhaust pipe, and the other part enters one or more adjacent activated carbon beds through the throttle valve for formaldehyde desorption, and the air from the activated carbon bed for formaldehyde desorption is discharged. The gas is sent to a compression device through a solenoid valve for compression, and the other end of the compression device is also provided with a chemically modified activated carbon bed for chemical adsorption of formaldehyde.

Description

Formaldehyde adsorption device

technical field

The invention belongs to the technical field of gas adsorption, and in particular relates to a formaldehyde adsorption device.

Background technique

At present, the adsorption of formaldehyde usually adopts physical adsorption and chemical adsorption. The physical adsorption method uses activated carbon to physically adsorb formaldehyde. This physical adsorption belongs to the van der Waals force between molecules, which is easy to be saturated, easy to desorb and lead to secondary Therefore, the activated carbon physical adsorption method cannot completely absorb the long-term release of formaldehyde in building materials.

The chemical adsorption method is a process of oxidizing pollutants such as formaldehyde into non-toxic and harmless substances by using the surface functional groups of the adsorbent (activated carbon). new chemical bonds. Since pollutants such as formaldehyde are oxidized and new stable chemical bonds are formed, the chemical adsorption method does not have the problem of secondary pollution caused by the desorption of formaldehyde. Passive adsorption is carried out in the environment, and the treatment efficiency is not high. In addition, the adsorption methods currently on the market have disadvantages such as easy saturation of the adsorbent and troublesome regeneration.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the above-mentioned deficiencies of the prior art, and to provide an adsorption device that can realize real-time regeneration of formaldehyde adsorbent and continuous adsorption of formaldehyde.

The technical scheme of the present invention is: a formaldehyde adsorption device, comprising an activated carbon bed for adsorbing or desorbing formaldehyde, an air compressor for sucking formaldehyde-containing air from the formaldehyde environment space and feeding it into the activated carbon bed, and the activated carbon bed is provided with at least two , A throttle valve is installed between the adjacent activated carbon beds, and the connecting pipe between each end of the throttle valve and the activated carbon bed is connected with an exhaust pipe, and the formaldehyde-containing air is compressed and sent to one or more The activated carbon bed is used for formaldehyde adsorption. Part of the air from the activated carbon bed for formaldehyde adsorption is discharged through the exhaust pipe, and the other part enters one or more adjacent activated carbon beds through the throttle valve for formaldehyde desorption. The gas coming out of the bed is sent to a chemically modified activated carbon bed that can chemically adsorb and oxidize formaldehyde through a solenoid valve, and the gas is directly discharged to the outside after formaldehyde adsorption through the chemically modified activated carbon bed.

The further technical scheme of the present invention is that it further comprises a heating device capable of heating the formaldehyde environment space.

A further technical solution of the present invention is that the heating device is a heating blower pump.

A further technical solution of the present invention is that: the formaldehyde environment space is provided with a temperature detector at the air inlet of the heating blower pump and/or at the formaldehyde-containing air outlet.

The further technical scheme of the present invention is as follows: the number of activated carbon beds is two, and the solenoid valve is a four-position two-way solenoid valve.

A further technical solution of the present invention is that a condenser for condensing formaldehyde-containing air is further arranged between the air compressor and the solenoid valve.

A further technical solution of the present invention is that a drying pipe is arranged between the condenser and the solenoid valve to dry the air containing formaldehyde.

A further technical solution of the present invention is that: a formaldehyde detector is also provided at the gas discharge end of the chemically modified activated carbon bed.

A further technical solution of the present invention is that the number of chemically modified activated carbon beds is 2, and an electromagnetic switching valve for switching the gas flow line is provided between the electromagnetic valve and the chemically modified activated carbon bed.

A further technical solution of the present invention is that: a formaldehyde detector is also installed at the air discharge end of the exhaust duct.

Compared with the prior art, the present invention has the following characteristics:

1) At least two activated carbon beds are used for pressurized adsorption and depressurized desorption, respectively, to complete the periodic cycle of adsorption and desorption operations, and realize the real-time "regeneration" of the adsorbent (activated carbon) in vacuum pressure swing adsorption, without the need to stop to replace the carbon The activated carbon in the bed can continuously adsorb formaldehyde in the air and separate formaldehyde from the air;

2) After the return valve transports the gas to the activated carbon bed for formaldehyde desorption, the formaldehyde concentration in the purged mixed gas becomes higher than the original mixed gas concentration, that is, the formaldehyde is concentrated, which will also help to improve the subsequent chemically modified activated carbon bed. Oxidation efficiency, greatly reducing the amount of chemically modified activated carbon;

3) Warming up the formaldehyde environment space can accelerate the release of formaldehyde and strive for the maximum adsorption efficiency of the formaldehyde adsorption device;

4) The formaldehyde environment space is equipped with temperature detectors at the air inlet of the heating blower pump and the formaldehyde-containing air outlet, which can monitor the temperature of the formaldehyde environment space in real time and ensure that the temperature in the space is controlled at the temperature most conducive to the release of formaldehyde. At the same time, it also avoids damage to the structure and surface of wood furniture due to excessive temperature;

5) Set up two chemical activated carbon beds, and at the same time control the work of each activated carbon bed through an electromagnetic switching valve, and immediately start another chemically modified activated carbon bed to oxidize formaldehyde when any chemically modified activated carbon bed is saturated with adsorption;

6) A formaldehyde rapid detector is installed at the gas discharge end of the chemically modified activated carbon bed, which can prompt the adsorption and oxidation switching of formaldehyde between the two chemically modified activated carbon beds in real time, so as to ensure that the final gas discharged to the outside is clean air;

7) Activated carbon uses honeycomb activated carbon, which effectively reduces the resistance of activated carbon during desorption, that is, reduces the amount of clean air used for desorption.

The detailed structure of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the structural representation of the formaldehyde adsorption device described in embodiment 1;

Figure 2a is a schematic diagram of the first half-cycle working principle of the activated carbon bed in Figure 1 for adsorption and desorption of formaldehyde;

Figure 2b is a schematic diagram of the working principle of the second half cycle of the adsorption and desorption of formaldehyde by the activated carbon bed in Figure 1 .

Detailed ways

Example 1

As shown in Figure 1, a formaldehyde adsorption device includes a plurality of activated carbon beds 11 for adsorbing or desorbing formaldehyde, an air compressor 2 for sucking out formaldehyde-containing air from the formaldehyde environment space A and feeding it into the activated carbon bed, and the activated carbon bed 11 There are at least two, and a throttle valve 12 is installed between the adjacent activated carbon beds, so that the airflow can circulate between the adjacent activated carbon beds 11; the connecting pipes between each end of the throttle valve 12 and the activated carbon bed are connected Gas pipeline 13, the air containing formaldehyde is sent into one or more activated carbon beds for formaldehyde adsorption through solenoid valve 14 after being compressed, and part of the air from the activated carbon bed for formaldehyde adsorption is discharged through exhaust pipe 13 (adsorbed by activated carbon bed) After the air is clean air), the other part enters the adjacent one or more activated carbon beds 11 through the throttle valve 12 for formaldehyde desorption, and the exhaust pipe 13 is provided with a valve (see reference numerals 95 and 95 in Figure 2a and 2b). 96), in order to prepare the valve on the corresponding exhaust pipe to discharge clean air when different activated carbon beds are in adsorption operation; the gas from the activated carbon bed for formaldehyde desorption is sent through the solenoid valve 14 to a chemical that can chemically desorb formaldehyde. In the chemically modified activated carbon bed 31 treated by adsorption and oxidation, the gas is directly discharged to the outside after formaldehyde adsorption through the chemically modified activated carbon bed 31.

This embodiment mainly overcomes the defect that the activated carbon bed cannot achieve continuous adsorption of formaldehyde in the prior art. By setting up multiple activated carbon beds, the activated carbon bed can perform both formaldehyde adsorption and formaldehyde desorption, and the multiple activated carbon beds are respectively used for formaldehyde adsorption and desorption. The formaldehyde is circulated in the process, that is, at the same time, some activated carbon beds are adsorbing formaldehyde, while some activated carbon beds are desorbing formaldehyde, so as to realize the continuous "regeneration" of activated carbon in the activated carbon bed, so that the adsorption of formaldehyde can continue without the need for traditional adsorption devices. Generally, it is necessary to stop and replace the activated carbon.

Specifically, the number of activated carbon beds 11 in this embodiment is two, and accordingly, the solenoid valve 14 is a four-position two-way solenoid valve, and only two activated carbon beds are provided to completely realize the adsorption and desorption cycle process of formaldehyde, which saves the overall cost of the device. cost.

Because formaldehyde is released quickly above 25°C, the adsorption device also includes a heating device 4 that can heat up the formaldehyde environmental space A, so that the formaldehyde can be released in a concentrated manner to the maximum extent. The heating device 4 generally uses a heating blower pump. It transports heat source air to the formaldehyde environment space to heat up. In addition, the formaldehyde environment space is provided with a temperature detector 5 at the air inlet of the heating blower pump and the formaldehyde-containing air output port to monitor the temperature of the formaldehyde environment space A in real time. To ensure that the formaldehyde environment space is in a heated state, and secondly, to avoid damage to the structure and surface of wood furniture due to excessive temperature.

In order to make the air quality of the formaldehyde-containing air entering the activated carbon bed better, to avoid the poor adsorption effect of activated carbon caused by excessive humidity, it is also necessary to absorb the moisture of the air containing formaldehyde. The adsorption device is between the air compressor 2 and the solenoid valve 14. Also provided with a condenser 6 for condensing the formaldehyde-containing air, and a drying pipe 7 for drying the formaldehyde-containing air. After being processed by the condenser and the drying pipe, the formaldehyde-containing air is in a dry state, which is beneficial for the activated carbon to quickly sterilize the formaldehyde. adsorption.

In general, a four-position two-way solenoid valve, two activated carbon beds and a throttle valve constitute the pressure swing adsorption part of the adsorption device for physical adsorption and desorption cycle treatment. The pressure change of the pressure swing adsorption is determined by the air compressor. Provide, concentrating formaldehyde-containing air while realizing adsorbent regeneration. The concentration of formaldehyde-containing air pointed out here means that the formaldehyde concentration input from the four-position two-way solenoid valve is stable, and after the vacuum pressure swing adsorption part of the treatment, part of the clean air is discharged through the exhaust pipe, and the other part of the clean air passes through. The throttle valve enters the activated carbon bed that desorbs formaldehyde to purge the activated carbon that adsorbs formaldehyde, and the desorbed formaldehyde is mixed with this part of the clean air, the proportion of formaldehyde increases, and the concentration of formaldehyde increases, so formaldehyde is concentrated. The concentration of formaldehyde-containing air will help to improve the adsorption and oxidation efficiency of the subsequent chemically modified activated carbon bed to formaldehyde, and also reduce the amount of activated carbon used in the chemically modified activated carbon bed.

In order to ensure that the air discharged to the outside is formaldehyde-free air, a formaldehyde detector 8 is also installed at the air discharge end of the exhaust duct. Once it is detected that the straight exhaust air contains formaldehyde, another activated carbon bed 11 is immediately activated.

Vacuum pressure swing adsorption is to use the adsorption characteristics of the adsorbent to change the adsorption effect of different gas components with the pressure change, and realize the gas separation through periodic pressure changes, that is, the two activated carbon beds are pressurized adsorption and depressurized desorption respectively ( The pressurization and depressurization of the two activated carbon beds are controlled by the switching of the air compressor and the four-position two-way solenoid valve respectively), and the adsorption and desorption operations are periodically cycled to realize the reuse of the adsorbent after regeneration to separate formaldehyde and air. the process of.

The working principle of vacuum pressure swing adsorption is shown in Figure 2(a) and Figure 2(b). Φ is the mass flow rate; λ is the ratio of the mass flow rate of the gas flow used for desorption to the total gas flow entering the activated carbon bed for adsorption. The direction of airflow is controlled by the throttle valve, and one cycle is divided into two half cycles with opposite airflow directions. Figure 2(a) and Figure 2(b) are the upper half cycle and the lower half cycle, respectively. In the first half cycle, the valve 91, 93, 96 are turned on, 92, 94, and 95 are turned off, and the compressed gas Φ enters the activated carbon bed on the right side through valve 93. When the pressure is increased, the adsorption capacity of activated carbon to formaldehyde increases, and the formaldehyde in the air is adsorbed and separated. After adsorption, a part of the clean air flow (1-λ)·Φ is output to the external environment through the valve 96, and the other part of the air flow λ·Φ is input to the left activated carbon bed through the throttle valve, and when the activated carbon bed is depressurized there The formaldehyde is desorbed and washed out from the activated carbon, the desorption speed of formaldehyde is accelerated, and the amount of depressurized desorption gas flow λ·Φ is reduced. At the same time, the regeneration of activated carbon is completed during desorption, and the concentrated formaldehyde-containing air is sent through valve 91. The chemically modified activated carbon bed is oxidized; when the device enters the second half cycle, valves 92, 94, and 95 are opened, and valves 91, 93, and 96 are closed, and the adsorption and desorption roles of the two activated carbon beds are exchanged, and the working state is the same as the first half cycle. on the contrary. The adsorption and desorption time are controlled by adjusting the time interval between opening and closing of the valve (of course, the adsorption and desorption time need to be determined experimentally. Taking the activated carbon of the activated carbon bed 11 as an example, the activated carbon can effectively adsorb formaldehyde in the air in the first half cycle, and in the next The desorption is complete in half a cycle, so that formaldehyde can be continuously collected without adsorption saturation, adsorption time = desorption time = valve switching time), and the size of the desorption gas flow is controlled by the opening and closing degree of the throttle valve (the opening and closing degree of the throttle valve is mainly It refers to the desorption gas flow ratio λ, which is the ratio of the mass flow rate of the air flow used for desorption to the total air flow entering the activated carbon bed for adsorption. The comprehensive adjustment enables the PSA part to run continuously and stably, that is, to discharge clean air and concentrated formaldehyde continuously and stably.

The number of chemically modified activated carbon beds 31 is 2, and an electromagnetic switching valve 32 for switching the gas flow direction is provided between the solenoid valve 14 and the chemically modified activated carbon bed 31, so that the gas sent from the solenoid valve 14 only enters one of them at a time Formaldehyde adsorption and oxidation is carried out in the chemically modified activated carbon bed 31; the significance of this setting is that it takes time for formaldehyde to oxidize in the chemically modified activated carbon bed, and the activated carbon in the activated carbon bed will be saturated with adsorption, and the two chemically modified activated carbon beds will be saturated. Then it can be ensured that after any one of the activated carbon beds is saturated with adsorption, there is still one activated carbon bed that can continue to carry out the work of formaldehyde adsorption and oxidation.

In order to ensure complete oxidation of formaldehyde, and then to ensure that the gas discharged to the outside is clean air, a formaldehyde detector 8 is also provided at the gas discharge end of the chemically modified activated carbon bed 31. Once the formaldehyde rapid detector detects that the formaldehyde exceeds the standard, it means that the formaldehyde oxide is oxidized. The chemically modified activated carbon bed 31 is already in the adsorption saturation state, and the activated carbon bed needs to be switched. At this time, the electromagnetic switching valve 32 is immediately switched to another chemically modified activated carbon bed for formaldehyde adsorption, and the activated carbon bed in the saturated state needs to be replaced with activated carbon, In general, the device combines physical adsorption in the pressure swing adsorption stage and chemical adsorption in the adsorption and decomposition of chemically modified activated carbon, and improves the treatment efficiency through pressure swing physical adsorption, that is, continuous adsorption and concentration of formaldehyde without the need to replace activated carbon, Increase the processing capacity and processing efficiency of activated carbon,

The adsorption device for removing formaldehyde in this embodiment has the advantages of simple adsorption process, easy-to-obtain and regenerable adsorbent, fast adsorption reaction speed, high efficiency, less environmental impact, and no secondary pollution.

The present invention is not limited to the above-mentioned specific structure or connection mode, as long as it is an adsorption device having substantially the same structure or connection mode as the application, it falls within the protection scope of the present invention.

Claims (10)

1. a kind of formaldehyde absorbing device, it is characterized in that: including for adsorbing or solving active-carbon bed (11) of absorbing formaldehyde, formaldehyde will be contained Air is sucked out and is sent into active-carbon bed air compressor (2) from formaldehyde environment space (A), and active-carbon bed (11) are equipped at least two It is a, be equipped between adjacent active charcoal bed throttle valve (12), each end of throttle valve and it is active-carbon bed between connecting pipe on connect Have exhaust pipe (13), air containing formaldehyde is sent into one or more active-carbon bed carry out first by solenoid valve (14) after being compressed Aldehyde absorption, from carry out formaldehyde absorbing it is active-carbon bed in come out air a part by exhaust pipe (13) discharge, another portion Divide and enter the adjacent active-carbon bed progress formaldehyde desorptions of one or more by throttle valve (12), from the activity for carrying out formaldehyde desorption Charcoal bed come out gas by solenoid valve (14) be sent into one can PARA FORMALDEHYDE PRILLS(91,95) carry out chemisorption oxidation processing chemical modification activity Charcoal bed (31), gas are in line to extraneous after the active-carbon bed progress formaldehyde absorbing of chemical modification.

2. formaldehyde absorbing device according to claim 1, it is characterized in that: further include can the heating of PARA FORMALDEHYDE PRILLS(91,95) environment space plus Warm device (4).

3. formaldehyde absorbing device according to claim 2, it is characterized in that: heating apparatus (4) is heat blowing pump.

4. formaldehyde absorbing device according to claim 2 or 3, it is characterized in that: formaldehyde environment space heat blowing pump into Temperature monitor (5) are equipped at wind inlet and/or air-out containing formaldehyde.

5. formaldehyde absorbing device according to claim 1 or 2, it is characterized in that: active-carbon bed is 2, solenoid valve (14) is Four two-way electromagnetic valves.

6. formaldehyde absorbing device according to claim 5, it is characterized in that: between air compressor (2) and solenoid valve (14) It is additionally provided with the condenser (6) for being condensed to air containing formaldehyde.

7. formaldehyde absorbing device according to claim 6, it is characterized in that: being arranged between condenser (6) and solenoid valve (14) There is drying tube (7) that air containing formaldehyde is dried.

8. formaldehyde absorbing device according to claim 1, it is characterized in that: the gas of chemical modification active-carbon bed (31) is discharged Methylene oxide detecting instrument (8) are additionally provided at end.

9. formaldehyde absorbing device according to claim 8, it is characterized in that: chemical modification active-carbon bed (31) setting quantity is 2, solenoid valve and chemical modification it is active-carbon bed between be equipped with electromagnetic switching valve (32) for switching gas flow route.

10. formaldehyde absorbing device according to claim 1, it is characterized in that: the air outlet side of exhaust pipe (13) is also pacified Equipped with methylene oxide detecting instrument (8).