WO2023070665A1 - Ventilation cabinet having circulating self-cleaning structure - Google Patents

Abstract

The present invention relates to a ventilation cabinet having a circulating self-cleaning structure, the ventilation cabinet comprising an air intake port (1), a fan (2), an air purification, filtering and regeneration device (3), and a circulating air replenishment port (4), which are connected in sequence by means of a pipeline. The circulating airflow enters the air purification, filtering and regeneration device (3) through the air intake port (1), and is purified and then replenished in the ventilation cabinet through the air replenishment port (4). Compared with the prior art, according to the present invention, the total output air volume of the ventilation cabinet is reduced on the premise of ensuring that harmful volatiles can be discharged effectively and rapidly during an operation process.

Description

A kind of circulating self-cleaning structure fume hood technical field

The invention relates to the field of air purifiers, in particular to a fume hood with a circulating self-cleaning structure.

Background technique

The environmental requirements of the laboratory are generally relatively high. Because the laboratory will store some commonly used volatile test reagents, these volatile reagents usually produce volatile gases, some of which are poisonous and harmful. Environmental impact will not only affect the accuracy of test data, but harmful gases will also affect the physical and mental health of experimenters. Therefore, laboratories usually have corresponding exhaust systems to update the ambient air in the laboratory in a timely manner.

Experimental ventilation equipment is widely used in a series of research places such as hospitals, schools, and various research institutes. Fume hoods are an indispensable part of laboratory ventilation design. In order to prevent laboratory workers from inhaling some toxic and For chemical substances and organisms with unknown toxicity, the laboratory should have good ventilation. The most important function of the fume hood is the exhaust function. In the chemical laboratory, various harmful gases and odors are produced during experimental operations. , moisture, and flammable, explosive, and corrosive substances. In order to protect the safety of users and prevent the spread of pollutants in the experiment to the laboratory, operations involving pollution sources should be carried out in a fume hood.

At present, the structure of the laboratory fume hood is shown in Figure 1. This fume hood includes a workbench 101, a cabinet door 102, an air duct 103 and a cabinet top air outlet 104. When in use, the cabinet door 102 is opened, and the fan blows the indoor air from the cabinet The door 102 is inhaled into the fume hood to take away the polluted gas produced on the workbench 101, and then discharge it from the air duct 103, and discharge it into the atmosphere through the air outlet 104 on the top of the cabinet. This kind of fume hood has the deficiencies in the following aspects. 1. When the fume hood door is opened for related operations, the indoor air is pumped to the outside by the exhaust fan through the pipeline system. In this process, the airflow distribution is uneven. It is easy to generate turbulent flow, causing some harmful gases to be unable to be discharged in a timely and effective manner. In order to discharge the harmful gases generated in the experiment to the outside more thoroughly, it is often necessary to increase the air volume and wind speed of the exhaust air to the outside, and a large amount of fresh air is required indoors. , At the same time, accompanied by a large amount of indoor air discharge, the load on the air conditioning unit system is greatly increased, resulting in a large amount of power consumption. If natural supplementary air is used in order to reduce energy consumption, it will also affect the working comfort of experimental operators.

Contents of the invention

The object of the present invention is to provide a kind of circulating self-cleaning structure fume hood which can ensure that the harmful gas can be effectively and quickly discharged in order to overcome the above-mentioned defects in the prior art, and reduce the external exhaust air volume of the fume hood.

The purpose of the present invention can be achieved through the following technical proposals: a kind of circulating self-cleaning structure fume hood, including the air inlet, blower fan, air purification filter and regeneration device and supplementary air inlet that are connected successively by pipeline, and described air inlet makes the air inlet uniform Enter the air purification filter and regeneration device to purify, and after evolution, fill it back into the fume hood through the air supply port.

Further, the air inlet is an elongated opening formed between the elongated wing plate and the workbench of the fume hood, the size of the air inlet can be controlled by adjusting the turning angle of the wing plate, thereby controlling the air inlet speed, so that the air inlet The wind is even.

Further, the fan is installed between the air inlet and the air purification filter and regeneration device, and sucks the gas in the fume hood into the air purification filter and regeneration device from the air inlet.

Further, the fan is an ultra-quiet pipeline fan, which is controlled by frequency conversion, and the running speed can be adjusted. The running speed of the fan is automatically adjusted according to the opening range of the fume hood cabinet door, or the running speed is manually set through the operation panel. Ultra-quiet design, the operating noise is below 55 decibels.

Further, the air purification filter and regeneration device includes a cavity, and a composite activated carbon filter element arranged in the cavity, and a conductive coil is arranged in the composite activated carbon filter element;

During purification, the air containing harmful gases enters the cavity, and the harmful substances are absorbed by the composite activated carbon filter element, and the filtered clean air is discharged;

During regeneration, the conductive coil generates a magnetic field with high frequency changes. Under the action of the magnetic field, an eddy current will be generated inside the composite activated carbon filter element, which will heat the composite material and release the adsorbed harmful substances from the composite activated carbon filter element. outdoor.

Further, a temperature sensor is pre-embedded in the composite activated carbon filter element to precisely control the temperature of the filter material during regeneration and prevent the filter element from being damaged due to overheating.

Further, the cavity is divided into two cavities by the composite activated carbon filter core, wherein the first cavity is provided with an air inlet, the second cavity is provided with an exhaust port, and the air inlet is connected to a fan. The exhaust port is connected to the supplementary air port through the exhaust pipe.

Further, the exhaust port side of the air purification filter and regeneration device is also provided with a detection port, the detection port is connected to the air intake pipe in front of the air purification filter and regeneration device through a detection pipeline, and the detection pipeline is provided with VOC Detection sensor, differential pressure sensor and solenoid valve, among which the VOC detection sensor detects the air quality after purification, the differential pressure sensor detects the pressure difference before and after the air purification filter and regeneration device, and the solenoid valve is closed in the regeneration mode of the air purification filter and regeneration device , to protect the sensors on the detection pipeline.

Further, the air supply port is a long strip pipe arranged on the top of the fume hood, and the long pipe is provided with a uniform air outlet, and the purified air is discharged through the air supply port to form an air curtain.

The pipes connecting each component are made of PVC, PP or PTEF pipes, which have good acid and alkali corrosion resistance, and can be cut on site. The pipe joints adopt standard parts, which is convenient for construction and installation;

The fan casing is made of non-metallic materials with good acid and alkali corrosion resistance or metal materials with anti-corrosion coating.

The circulating self-cleaning structure (including the air inlet, fan, air purification filter and regeneration device and air supply port connected in sequence by the above-mentioned pipelines) can be arranged inside the bottom cabinet of the fume hood, or on the top of the fume hood; the way of supplying air to the fume hood Air can be supplied to the front upper or lower corner of the inside of the fume hood; air can also be supplemented to the outside of the fume hood.

Compared with the prior art, the present invention has the following beneficial effects:

One, the fume hood of the present invention is provided with an air cleaning device, which will have a broad-spectrum purification ability to volatile pollutants, and adopts the internal purification of polluted air in the fume hood, and the circulation mode reduces the exhaust air volume of the fume hood, thereby realizing Significant energy saving effect. The exhaust part of the fume hood enters the purification device, and after purification, it enters the internal circulation of the fume hood to increase the air volume inside the fume hood and reduce the concentration of pollutants.

2. The filter element used for air purification adopts a renewable working method to realize the recycling of the filter element, which greatly prolongs the service life of the filter element, thereby reducing the use and maintenance cost of the fume hood.

3. The regeneration of the filter element used in air purification can be set to be carried out automatically at night when no one is working, so as to avoid interference with the work of the operator during the day.

4. Install an air curtain device above the front and top of the operator, which is the air supply port, to generate an air curtain to protect the operator's head, and form a protective air curtain on the operating window to prevent the operator from inhaling pollutants through the mouth and nose, causing physical damage ;

5. Set the supplementary air wing at the edge of the table below the window, that is, the wing plate air inlet. The supplementary air wing can maintain the air volume in the room when the window of the fume hood is closed, so as to balance the exhaust air volume and prevent turbulent flow.

6. Convenient maintenance: the air purification and regeneration device is installed in the bottom cabinet, which has a large working space and is easy to install and disassemble.

Description of drawings

Fig. 1 is the structural representation of existing fume hood;

Fig. 2 is the structural representation of the circulation self-cleaning structure fume hood of the present invention;

Fig. 3 is a schematic diagram of the opening state of the fume hood cabinet door of the circulation self-cleaning structure of the present invention;

Fig. 4 is the structure schematic diagram of circulating air purification system of the present invention;

Fig. 5 is a structural schematic diagram of the air purification filtration and regeneration device and its pipeline connection system of the present invention;

Fig. 6 is a structural schematic diagram of the air purification filter and regeneration device of the present invention;

Fig. 7 is the structural representation of Embodiment 2 of the circulating self-cleaning structure fume hood of the present invention;

Fig. 8 is the embodiment 3 structural representations of circulating self-cleaning structure fume hood of the present invention;

Fig. 9 is the schematic structural view of Embodiment 4 of the circulating self-purifying structure fume hood of the present invention;

Fig. 10 is a structural schematic diagram of Embodiment 5 of the circulating self-purifying fume hood of the present invention.

Detailed ways

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

The composite activated carbon filter element 32 in the air purification filter and regeneration device 3 of the present invention is a regenerative activated carbon filter element developed by Dezhao Technology (Shanghai) Co., Ltd., and the filter element is wrapped and assembled by activated carbon and a wire filter, wherein the activated carbon is The particle size is 5mm, the pore size is 0.1mm, and the specific surface area is >300m2/g. The structure of activated carbon is due to the irregular arrangement of microcrystalline carbon, and there are pores between the cross-links. With adsorption, organic gas molecules are adsorbed and stored in the capillary of activated carbon. At high temperature, the Brownian motion of molecules is strengthened, and the organic molecules in the capillary of activated carbon get rid of the adsorption of the capillary and are released from the activated carbon. The conductive coil adopts a high-frequency electromagnetic coil, which is made of thin copper wire and a bracket that is insulated and encapsulated. When energized, the composite activated carbon filter element can be heated to above 100 degrees Celsius to desorb the adsorbed organic matter. Other raw materials used in the present invention are all commercially available materials, and various sensors used are commercially available sensors commonly used in this field.

Example 1

As shown in Figure 2, a fume hood with circulating self-cleaning structure, the arrow shows the direction of air flow, includes a workbench 101, a cabinet door 102, an air duct 103 and a cabinet top air exhaust port 104, and also includes inlets and outlets connected in sequence through pipelines. The air inlet 1, the fan 2, the air purification filter and regeneration device 3 and the air supply port 4, the air inlet 1 allows the incoming air to enter the air purification filter and regeneration device 3 for purification, and after evolution, it is replenished in the fume hood through the air supply port 4. Figure 2 is the closed state of the cabinet door, and Figure 3 is the open state of the cabinet door.

In the present invention, the main source of supplementary air for the fume hood is to absorb the volatile organic matter and other substances that may cause harm to the human body by purifying and filtering the polluted air in the fume hood, and then pass the purified air through the pipeline fan. air back into the fume hood. This prevents the air in the room from being pumped outdoors in large quantities as make-up air. At the same time, due to the use of air purification technology, the concentration of pollutants has been greatly reduced, and the amount of air discharged to the outside has been significantly reduced. The load of the air conditioning unit system is significantly reduced, thereby achieving the purpose of energy saving.

Fig. 4 is a schematic structural diagram of the circulating air purification system of the present invention, and the arrows indicate the direction of air flow.

Wherein the workbench 101 is provided with a strip-shaped wing plate near the edge of the cabinet door 102, and the strip-shaped opening formed between the strip-shaped wing plate and the fume hood workbench is the air inlet 1. By adjusting the turning angle of the wing plate, the control The size of the air inlet can control the speed of the air inlet to make the air inlet even.

The pipes and fittings are all made of PVC or PP pipes, which have good acid and alkali corrosion resistance, and can be cut on site. The pipe joints are made of standard parts, which is convenient for construction and installation. Low, easy to install, conducive to the popularization and application of this face.

The fan 2 is installed between the air inlet 1 and the air purification filter and regeneration device 3, and the gas in the fume hood is sucked into the air purification filter and regeneration device 3 from the air inlet 1. Fan 2 is an ultra-quiet pipeline fan, which adopts frequency conversion speed regulation control, and the running speed can be adjusted. The noise is below 35 decibels. The ultra-quiet design of the fan 2 has very low noise during operation. At the same time, because of the frequency conversion speed regulation technology, the speed of the motor can be adjusted, so the air volume of the fan can be adjusted according to the demand, so as to achieve further energy-saving operation.

As shown in Figures 5-6, the air purification filter and regeneration device 3 includes a cavity 31, and a composite activated carbon filter core 32 arranged in the cavity 31, and a conductive coil 33 is arranged in the composite activated carbon filter core 32 A temperature sensor 34 is pre-embedded in the composite activated carbon filter element 32 to precisely control the temperature of the filter material during regeneration and prevent damage to the filter element caused by overheating. The shell 37 of the air purification filter and regeneration device 3 can be rectangular, or square or circular, or other shapes. In this embodiment, it is a rectangular structure. 32 is divided into two cavities, wherein the first cavity is provided with an air inlet 35, and the second cavity is provided with an exhaust port 37, and multiple exhaust ports can be provided. In this embodiment, the exhaust port is provided with There are two, two exhaust ports, the air inlet 35 is connected to the blower fan 2, and the two exhaust ports 37 are connected to the two ends of the supplementary air port 4 through two exhaust pipes 62.

A plurality of sensors have been adopted in the fume hood to detect the system operating conditions. Specifically, as described in FIGS. The port 36 is connected to the air intake pipeline before the air purification filter and regeneration device 3 (in this embodiment, connected to the intake pipeline 61 before the blower fan 2) through the detection pipeline 5, and the detection pipeline 5 is provided with a VOC detection sensor 51 , Differential pressure sensor 52 and solenoid valve 53.

Among them, the VOC detection sensor 51 detects the air quality after purification, and the pressure difference sensor 52 detects the pressure difference before and after the air purification filter and regeneration device 3. When the filter element is blocked, the pressure difference sensor 52 can detect the rise of the front and rear pressure. When a set value is set, it means that the filter element may be clogged to a certain extent, and the filter element needs to be inspected, maintained or replaced. The control system will send out an alarm to notify the user to check and replace the filter element. The solenoid valve 53 is in the regeneration mode of the composite activated carbon filter element 32 of the air purification filter and regeneration device 3, the solenoid valve 53 is closed, and the air detection pipeline 5 is cut off, thereby protecting the VOC detection sensor 51 at the rear end and avoiding its long-term exposure In a high-concentration VOC environment, the aging or damage of the VOC detection sensor is caused. The VOC detection sensor 51 is used to detect the VOC content in the air filtered by activated carbon under the purification mode of the air purification filter and regeneration device 3. When the air When the VOC content in the air exceeds a certain concentration, the fan speed will be automatically adjusted to increase the ventilation volume and a reminder will be issued to remind the operator to increase the exhaust or perform equipment inspection.

The air supply port 4 is a strip-shaped pipeline arranged on the top of the fume hood. The strip-shaped pipeline is provided with a plurality of evenly arranged air outlets, and the purified air is discharged through the air supply port to form an air curtain to protect operators. The head forms a protective air curtain on the operating window to prevent the operator from inhaling pollutants through the mouth and nose, causing physical damage.

The air purification filter and regeneration device 3 of the present invention has two kinds of working modes: air cleaning working mode and regeneration working mode:

In the air purification mode, the polluted air is driven by the fan 2, flows from the air inlet 1, along the air intake pipe 61, and enters the air purification filter and regeneration device 3, and the VOC and other harmful substances are filtered by the composite activated carbon filter element 32 The concentration of volatile substances such as VOC in the air is gradually reduced. When the harmful substances such as VOC adsorbed in the composite activated carbon filter core 32 continue to accumulate to a certain extent, in order to ensure that the composite activated carbon filter core 32 can continue to To adsorb harmful substances such as VOC, it is necessary to regenerate the adsorption function of the activated carbon filter;

In the regenerative working mode, the conductive coil 33 embedded in the composite activated carbon filter core 32 is fed with high-frequency alternating current to generate a high-frequency changing magnetic field, and the ferromagnetic material in the composite activated carbon filter core 32 is , the induction generates eddy currents, so that the composite activated carbon filter core 32 is heated, so that harmful substances such as VOC in the composite activated carbon filter core 32 are released, and are discharged from the air outlet 104 on the top of the cabinet through the air duct 103. After a certain period of time After regeneration, the composite activated carbon filter element 32 resumes the adsorption function. Regeneration is generally set at night (the specific time can be set, such as 0:00 to 2:00). When there is no staff operating the fume hood, it will automatically run. The wind device discharges the air containing VOC and other harmful substances in the fume hood to the outside to avoid the pollution from being released into the room. The temperature sensor 34 is embedded in the filter element, which can accurately control the temperature of the filter material when it is regenerated, and prevent the filter element from being damaged by overheating. .

comparative example

As shown in Figure 1, a conventional fume hood of a well-known American brand is used as a comparative example

The circulating self-cleaning structure fume hood described in Example 1 is compared with the fume hood described in the comparative example, both are the same in size, and the workbench 101, cabinet door 102, air duct 103 and cabinet top air outlet 104 are all the same, and the test is carried out.

The performance results are shown in the table below:

Test items	Example 1	comparative example
Total air volume outside the pipe	441m 3 /h	1100m 3 /h
Fume hood face velocity	0.46m/s	0.5m/s
Fume Hood Residual Concentration	0.01ppm	0.01ppm
Filter service life	24 months	none

As can be seen from the above table, under the premise that the fume hood of the present invention ensures that harmful gases can be effectively and quickly discharged, the total air volume of the fume hood is reduced. Thereby, the energy consumption consumed by the laboratory can be effectively reduced.

In general air-conditioned laboratories, the energy consumption of the fresh air load caused by the exhaust air from the laboratory to the outside is very high. Therefore, reducing the exhaust air volume is the key to reducing energy consumption.

Example 2

As shown in Figure 7, the circulating self-purification structure (including the air inlet 1, the fan 2, the air purification filter and regeneration device 3, and the air supply port 4 connected in sequence by the above-mentioned pipelines) is arranged on the top of the fume hood; the air is supplied to the outside of the fume hood. Ventilate the fume hood. All the other are with embodiment 1.

Example 3

As shown in Figure 8, the described air supply port 4 is arranged at the door of the fume hood, and the air is taken in from the backboard of the fume hood, and the air is supplemented from the upper part and the wing plate, and the rest are the same as in Embodiment 1.

Example 4

As shown in Figure 9, the circulation self-purification structure (comprising the air inlet 1, fan 2, air purification filter and regeneration device 3 and air supply port 4 connected in sequence by the above-mentioned pipelines) is arranged on the top of the fume hood, wherein (the circulation self-purification device enters the air from the ventilation Cabinet wing plate place introduces, and referring to shown in the air flow direction arrow at figure fume hood wing plate place.), all the other are with embodiment 2.

Example 5

As shown in Figure 10, the circulating self-cleaning structure includes the air inlet 1, the blower fan 2, the air purification filter and regeneration device 3 and the supplementary air outlet 4 connected in sequence by the above-mentioned pipelines, wherein the blower blower 2 is arranged in the air duct of the fume hood, and the entrance of the blower blower 2 is set There is a filtering device, and the outlet of the blower fan 2 is divided into two branches, one of which is directly connected to the external atmosphere, and the other branch is connected to the air purification filter and regeneration device 3, and the air supply port is arranged on the outside of the fume hood cabinet door (in this structure, The primary purification filter device and fan are installed in the space behind the deflector of the fume hood, which is convenient for installation and maintenance. A three-way valve is installed on the upper part of the fan to control the flow direction of the primary purified air. In the first flow direction, open the first valve 7 and discharge to Outdoors, in the second flow direction, open the second valve 8, pass through secondary purification and filtration as the supplementary air, and supply it to the outside of the fume hood door. Due to the secondary purification and filtration, the volatile harmful substances in the supplementary air are effectively removed. Avoid volatile harmful substances from escaping into the room, causing personal injury. During the regeneration process of the primary purification filter device, the first valve 7 is opened and the second valve 8 is closed, so that the air with high content of harmful substances is directly discharged to the outside. Instead of making up the wind in the fume hood as a back-up wind.).

Claims (10)

1. A kind of circulating self-cleaning structure fume hood, it is characterized in that, comprises the air inlet (1), blower fan (2), air purification filtering and regenerating device (3) and make-up air outlet (4) connected successively by pipeline, described circulating air flow Through the air inlet (1), it evenly enters the air purification filter and regeneration device (3), and after the purification treatment, it is replenished into the fume hood through the air supply port (4).
2. Circulating self-cleaning structure fume hood according to claim 1, is characterized in that, described air inlet (1) is the elongated opening that forms between elongated wing plate and fume hood workbench, through adjusting wing plate Flip the angle to control the size of the air inlet, so as to control the air inlet speed and make the air inlet even.
3. Circulating self-cleaning structure fume hood according to claim 1, characterized in that, the fan (2) is installed between the air inlet (1) and the air purification filter and regeneration device (3), and the gas in the fume hood is drawn from The air inlet (1) sucks in the air purification filter and regeneration device (3).
4. The fume hood with circulating self-cleaning structure according to claim 1, characterized in that, the fan (2) is an ultra-quiet pipeline fan, controlled by frequency conversion and speed regulation, the operating speed can be adjusted, and it is automatically adjusted according to the opening range of the fume hood cabinet door The running speed of the fan can be set manually through the operation panel. The fan blades adopt an ultra-quiet design, and the operating noise is below 55 decibels.
5. The circulation self-cleaning structure fume hood according to claim 1, characterized in that, the air purification filter and regeneration device (3) comprises a cavity (31), and a composite activated carbon filter core arranged in the cavity (31) (32), the composite activated carbon filter core (32) is provided with a conductive coil (33);

   During purification, the air containing harmful gases enters the cavity (31), and the harmful substances therein are absorbed by the composite activated carbon filter element (32), and the filtered clean air is discharged;

   During regeneration, the conductive coil (33) produces a magnetic field with high frequency changes. Under the action of the magnetic field, an eddy current will be generated inside the composite activated carbon filter (32), heating the composite material, so that the adsorbed harmful substances are released from the composite activated carbon filter. (32) is released and discharged to the outside.
6. The fume hood with circulating self-cleaning structure according to claim 5, characterized in that a temperature sensor (34) is pre-embedded in the composite activated carbon filter element (32) to accurately control the temperature when the filter material is regenerated to prevent overheating caused by The filter element is damaged.
7. Circulating self-cleaning structure fume hood according to claim 5, it is characterized in that, described cavity (32) is divided into two cavities by composite activated carbon filter element (32), wherein the first cavity is provided with The air port (35), the second cavity is provided with an exhaust port, the air inlet (35) is connected to the fan, and the exhaust port is connected to the supplementary air port (4) through the exhaust pipe.
8. According to claim 1 or 7 described circulating self-cleaning structure fume hood, it is characterized in that, the exhaust port side of described air purification filtration and regenerating device (3) is also provided with detection port (36), and this detection port (36 ) is connected to the intake pipe before the air purification filter and regeneration device (3) through the detection pipe (5), and the detection pipe (5) is provided with a VOC detection sensor (51), a differential pressure sensor (52) and a solenoid valve ( 53), wherein the VOC detection sensor (51) detects the air quality after purification, the pressure difference sensor (52) detects the pressure difference before and after the air purification filter and regeneration device (3), and the solenoid valve (53) is in the air purification filter and regeneration device (3) It is closed in the regenerative working mode to protect the sensors on the detection pipeline (5).
9. Circulating self-cleaning structure fume hood according to claim 1, is characterized in that, described supplementary air opening (4) is the elongated pipeline that is arranged on the fume hood top, and this elongated pipeline is provided with uniform air outlet, The purified air is discharged through the supplementary air outlet to form an air curtain;

   The pipes connecting each component are made of PVC or PP pipes, which have good acid and alkali corrosion resistance, and can be cut on site. The pipe joints are made of standard parts, which is convenient for construction and installation;

   The fan (2) casing is made of non-metallic material with good acid and alkali corrosion resistance.
10. The circulation self-cleaning structure fume hood according to claim 1, wherein the circulation self-purification structure is arranged inside the bottom cabinet of the fume hood, or arranged on the top of the fume hood; Make up the air at the upper or lower corner; or make up the air to the outside of the fume hood.

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