Method for replacing a high efficiency particulate air filter of a biological safety cabinet

Abstract

The application discloses a biosafety cabinet high-efficiency filter replacement operation method and relates to the technical field of biosafety cabinets.The existing filter purifies air through filtration, so as to ensure the cleanness of the biosafety cabinet.However, the filter needs to be replaced when the purification effect is poor, and the filter needs to be replaced for a period of time, so that the high replacement frequency brings inconvenience to the use of the biosafety cabinet.The application purifies air through the arrangement of different cover plates in sequence, and the dust in the air is removed during the purification.However, bacteria and other microorganisms are accompanied in the dust and other impurities, and the pre-treatment of the bacteria and microorganisms can avoid the delivery into the biosafety cabinet, so that the cleanness of the biosafety cabinet is ensured.The replacement of the biosafety cabinet filter is usually because the ideal filtering effect cannot be achieved, so that the filter needs to be replaced, the filtering effect is improved, the filter life is prolonged, the replacement operation frequency is reduced, and the operation is relatively more convenient.

Description

Technical Field

[0001] This invention relates to the field of biosafety cabinet technology, specifically a method for replacing the high-efficiency filter in a biosafety cabinet. Background Technology

[0002] A biosafety cabinet is a box-shaped, negative-pressure air-purifying safety device that prevents the aerosol release of hazardous or unknown biological particles during experimental procedures. It is widely used in research, teaching, clinical testing, and production in fields such as microbiology, biomedicine, genetic engineering, and biopharmaceuticals, and is the most basic safety protection equipment in the primary biosafety barrier of laboratories.

[0003] In response, Chinese patent application number CN112774739A discloses a biosafety cabinet with easy filter replacement and stable airflow. It includes a main body of the biosafety cabinet and an exhaust filter and a downcomer filter separately disposed within the main body. The exhaust filter is limited to a preset position at the top of the main body by an exhaust filter guide plate detachably fixed to it. The downcomer filter is limited to a preset position above the operating port of the biosafety cabinet by a downcomer filter guide plate. In a first state, the downcomer filter guide plate can be fixedly held onto the downcomer filter; in a second state, it can be positioned at a preset position suitable for filter replacement. This invention has fewer disassembly parts, saving operation time and avoiding the potential for installation errors caused by disassembling and assembling too many parts, thus reducing the skill requirements for replacement personnel. Furthermore, it avoids the waste of manpower caused by disassembling two parts when only one filter needs to be replaced.

[0004] After a certain number of years of use, biosafety cabinets accumulate a large amount of bacteria, dust, and various hazardous factors on their HEPA filters, clogging the filters' normal airflow and affecting the cabinet's air curtain. As the vertically descending airflow passes through the filters, contaminated bacteria can easily fall onto the lab bench, directly affecting experimental results. To ensure the safety of personnel, samples, and the environment, it is crucial to replace the biosafety cabinet's HEPA filters regularly. However, existing filters purify the air to ensure the cleanliness of the cabinet's interior, but they need to be replaced when their purification effect deteriorates. This frequent replacement process adds inconvenience to the use of biosafety cabinets.

[0005] To address the aforementioned issues, a method for replacing the high-efficiency filter in a biosafety cabinet is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for replacing the high-efficiency filter in a biosafety cabinet, which solves the problems of short filter filtration time and high replacement frequency in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for replacing the high-efficiency filter of a biosafety cabinet, characterized by the following steps: first, shutting down the biosafety cabinet, stopping the experiment, and disconnecting the power to the equipment;

[0008] Cleaning, fumigation and disinfection (neutralization) treatment: Remove fragile or sensitive items, add the calculated amount of disinfectant and neutralizer according to the volume of the biosafety cabinet, set the heating temperature, fumigation time, and neutralization time, and turn on the equipment;

[0009] After circulation and fumigation disinfection (neutralization) are completed, turn on the internal circulation component of the biosafety cabinet and run it for half an hour;

[0010] The purification and safety cabinet circulation components operate, and during the operation phase, the purification components work together to introduce clean air.

[0011] Replace the module, run the ventilation system for half an hour, and then replace the filter. Remove the original supply and exhaust HEPA filters and replace them with new supply and exhaust HEPA filters.

[0012] The integrity of the HEPA filter was tested and verified using the PAO photometer method.

[0013] Preferably, the biosafety cabinet includes a support base, an isolation cover is installed on the top of the support base, the isolation cover covers the upper surface of the support base, an isolation door is provided on one side of the front of the isolation cover, the isolation door and the isolation cover are movably connected, and a sealing gasket is provided on the contact part of the isolation door with the upper surface of the support base.

[0014] Preferably, the circulation assembly includes a delivery chamber, an exhaust pipe, an exhaust tube, and a filter box, and the circulation assembly participates in the introduction and delivery of outside air into the biosafety cabinet.

[0015] Preferably, the conveying chamber is installed inside the support base, and a filter box is installed at the top of the conveying chamber. The other end of the conveying pipe embedded inside the conveying chamber is embedded inside the filter box, and the conveying chamber and the filter box are internally connected by the conveying pipe.

[0016] Preferably, the purification component includes an inner liner seat, a positioning rod is embedded inside the inner liner seat, a cover plate is installed at the upper end of the positioning rod, and a guide plate is installed on one side of the inner liner seat. The guide plate is arc-shaped and its top end covers the cover plate.

[0017] Preferably, the included angle formed between the cover plate and the inner liner is an acute angle, and germicidal lamps are connected to both sides of the included angle area between the cover plate and the inner liner.

[0018] Preferably, a filter pad is fixedly connected to the bottom end of the inner liner, and a filter hole is opened at the upper end of the filter pad, and a filter sponge is provided on the front side of the filter pad.

[0019] Preferably, the filter sponge is embedded inside the germicidal lamp, the filter sponge is made of transparent material, and the interior of the filter sponge is provided with hexagonal cavities.

[0020] Preferably, in the module replacement process, the internal sheet filter screen of the filter box is replaced, and the filter sponge also needs to be replaced. During the replacement, the sponge is pulled out from inside the cover plate and inner liner, and the new filter sponge is embedded into the innermost part of the cover plate and inner liner to ensure that the filter sponge fits snugly between the cover plate and the filter holes.

[0021] Preferably, the germicidal lamp has a power of 10 watts to 200 watts and an ultraviolet radiation dose of 30-90 mJ / cm². 2 .

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The method for replacing the high-efficiency filter of a biosafety cabinet provided by this invention aims to reduce the maintenance frequency of the biosafety cabinet by improving the purification effect and working cycle of the filter. During air purification, different covers are arranged in sequence to purify the air. Dust in the air is removed during purification. However, dust and other impurities are accompanied by bacteria and other microorganisms. By pre-treating the bacteria and microorganisms, they can be prevented from being transported into the biosafety cabinet, thereby ensuring the cleanliness inside the biosafety cabinet. Usually, biosafety cabinet filters need to be replaced because they do not achieve the ideal filtration effect. By improving the filtration effect, the filter life can be extended, thereby reducing the frequency of replacement and making the operation more convenient. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the purification component of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the discharge pipe and the delivery pipe of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the filter pad and filter holes of the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the inner liner and cover plate of the present invention;

[0029] Figure 6This is a schematic diagram of the structure of the germicidal lamp and filter sponge of the present invention.

[0030] In the diagram: 1. Support base; 2. Isolation cover; 3. Isolation door; 4. Conveying chamber; 41. Conveying pipe; 42. Discharge pipe; 43. Filter box; 5. Purification component; 51. Inner liner; 52. Germicidal lamp; 53. Cover plate; 54. Guide plate; 55. Positioning rod; 56. Filter pad; 57. Filter hole; 58. Filter sponge. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings.

[0033] Combination Figures 1-6 The present invention provides a method for replacing the high-efficiency filter of a biosafety cabinet. The biosafety cabinet equipment includes a support base 1, an isolation cover 2 is installed on the top of the support base 1, the isolation cover 2 covers the upper surface of the support base 1, and an isolation door 3 is also provided on one side of the front of the isolation cover 2. The isolation door 3 and the isolation cover 2 are movably connected, and a sealing gasket is provided on the contact part of the isolation door 3 with the upper surface of the support base 1.

[0034] In the traditional use of biosafety cabinets, the filters in the biosafety cabinet are mainly used to purify impurities, microorganisms, and bacteria in the air of the external environment. However, as the usage period is extended, the filtration efficiency of the filters gradually decreases, and the filtration efficiency of the filters for dust, bacteria, and microorganisms is also reduced. As a result, these impurities can enter the interior of the biosafety cabinet. When the equipment inside the biosafety cabinet is tested, it is found that the internal environment does not meet the standards. Therefore, it is necessary to clean the interior and replace the filters.

[0035] Therefore, frequent filter replacements are very inconvenient in the use of biosafety cabinets, and reducing the frequency of replacements can reduce the labor intensity.

[0036] First, shut down the biosafety cabinet, stop the experiment, and disconnect the power to the equipment;

[0037] Cleaning, fumigation and disinfection (neutralization) treatment: Remove fragile or sensitive items, add the calculated amount of disinfectant and neutralizer according to the volume of the biosafety cabinet, set the heating temperature, fumigation time, and neutralization time, and turn on the equipment;

[0038] After circulation and fumigation disinfection (neutralization) are completed, the internal circulation component of the biosafety cabinet is turned on and run for half an hour. The circulation component includes a delivery chamber 4, an exhaust pipe 42, and a filter box 43. The circulation component is used to introduce and deliver outside air into the biosafety cabinet. The delivery chamber 4 is installed inside the support base 1. The filter box 43 is installed at the top of the delivery chamber 4. The other end of the delivery pipe 41 embedded inside the delivery chamber 4 is embedded inside the filter box 43. The delivery chamber 4 and the filter box 43 are connected internally through the delivery pipe 41. When purifying the inside, outside air is introduced through the fan installed inside the delivery chamber 4. After being introduced and filtered internally, the air is delivered to the inside of the filter box 43 through the delivery pipe 41, and then delivered to the inside of the isolation cover 2 through the exhaust pipe 42.

[0039] Purification, the safety cabinet circulation component is in operation. During the operation phase, the purification component 5 cooperates to complete the introduction of clean air. The purification component 5 includes an inner liner 51. A positioning rod 55 is embedded inside the inner liner 51. A cover plate 53 is installed on the upper end of the positioning rod 55. A guide plate 54 is installed on one side of the inner liner 51. The guide plate 54 is arc-shaped and its top covers the cover plate 53.

[0040] The angle formed between the cover plate 53 and the inner liner seat 51 is an acute angle. Germicidal lamps 52 are connected to both sides of the area where the angle between the cover plate 53 and the inner liner seat 51 is located. The power of the germicidal lamps 52 is 10 watts to 200 watts, and the ultraviolet radiation dose is 30-90 mJ / cm². 2 When microorganisms are exposed to UV-C ultraviolet radiation, the ultraviolet light directly affects the microorganism's DNA nucleic acid, especially the purine and pyrimidine base pairs. UV-C energy is powerful enough to directly break the bond between two adjacent purine or pyrimidine bases, leading to DNA strand breaks and damage.

[0041] DNA replication and cell life cycle are inhibited: DNA damage affects the DNA replication and cell division processes of microorganisms, thereby preventing the normal life cycle and reproductive capacity of microorganisms. After being exposed to ultraviolet light, microorganisms cannot replicate their DNA and divide their cells, eventually leading to their death. This process can be used to sterilize microorganisms contained in the air.

[0042] A filter pad 56 is fixedly connected to the bottom of the inner liner 51. A filter hole 57 is opened at the upper end of the filter pad 56. A filter sponge 58 is arranged on the front side of the filter pad 56. The filter sponge 58 is embedded in the inner side of the germicidal lamp 52. The filter sponge 58 is made of transparent material. In order to make it easier for ultraviolet rays to diffuse inside the filter sponge 58, it is made of transparent material to facilitate the refraction of light.

[0043] The filter sponge 58 also has hexagonal cavities inside. After air is introduced into the conveying chamber 4, it is transported upwards, passing through the filter sponge 58. After entering the filter sponge 58, the germicidal lamps 52, located on both sides of the filter sponge 58, directly irradiate the interior of the filter sponge 58 with ultraviolet light. The air enters the interior of the filter sponge 58 and filters dust and other impurities through the pores. The flow rate is relatively slow during this process. The ultraviolet light enters the interior of the filter sponge 58 to sterilize bacteria and microorganisms. Finally, the airflow is guided by the guide plate 54. The air gradually penetrates upwards. The four sets of inner liner seats 51, germicidal lamps 52, cover plates 53, guide plates 54, positioning rods 55, filter pads 56, filter holes 57, and filter sponges 58 are arranged vertically inside the conveying chamber 4. After being filtered and sterilized by the four sets of filter sponges 58, the air enters the filter box 43 and is then transported out through the discharge pipe 42. This not only filters impurities in the air but also sterilizes microorganisms, making the inside of the biosafety cabinet cleaner and reducing the probability of bacteria entering the biosafety cabinet. This further extends the service life of the filter and reduces the frequency of replacement.

[0044] Replace the module, run the ventilation for half an hour, and replace the filter. Remove the original supply and exhaust HEPA filters and replace them with new supply and exhaust HEPA filters. When replacing the module, select to replace the internal sheet filter of filter box 43. At the same time, the filter sponge 58 also needs to be replaced. During the replacement, pull it out from inside the cover plate 53 and inner liner seat 51. Insert the new filter sponge 58 into the innermost part of the cover plate 53 and inner liner seat 51, so that the filter sponge 58 is in close contact with the cover plate 53 and filter holes 57. Under this close contact, the filter sponge 58 can filter the air. The pores inside the four sets of filter sponges 58 are of different sizes. The pores inside the top filter sponge 58 are the smallest, and the pores inside the bottom filter sponge 58 are the largest, achieving a layer-by-layer filtration and purification effect.

[0045] Testing was conducted to verify the integrity of the HEPA filter, using the PAO photometer method to determine if the HEPA filter was intact.

[0046] Prepare the testing equipment: Prepare the PAO photometer equipment, including the light source, photometer, and particle generator;

[0047] Generating test particles: PAO particles with known particle concentration and size distribution are generated using a particle generator and introduced into the test system;

[0048] Introducing Particles into the Test System: PAO particles are introduced into the air filter system to be tested by uniformly introducing the PAO particles into the airflow through a sprayer or similar device, so that they pass through the filter to be tested.

[0049] Measuring particle concentration: At the inlet and outlet of the filter, a photometer is used to measure the particle concentration before and after particle transfer or retention to determine the filter efficiency. The photometer estimates the particle concentration by measuring the change in the intensity of transmitted or reflected light.

[0050] Calculate filtration efficiency: The filtration efficiency of the air filter is calculated by comparing the changes in particle concentration at the inlet and outlet.

[0051] The formula for filtration efficiency is as follows:

[0052] Filtration efficiency = (1 - outlet particle concentration / inlet particle concentration) × 100%.

[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for replacing the high-efficiency filter in a biosafety cabinet, characterized in that, The steps include: first, shutting down the biosafety cabinet, stopping the experiment, and disconnecting the power to the equipment; Cleaning, fumigation, disinfection, and neutralization treatment: Remove easily damaged or sensitive items; add the calculated amount of disinfectant and neutralizing agent according to the volume of the biosafety cabinet; set the heating temperature, fumigation time, and neutralization time; and turn on the equipment. After circulation, fumigation, disinfection, and neutralization are completed, the internal circulation component of the biosafety cabinet is turned on and run for half an hour. Purification, the safety cabinet circulation component is running, during the operation phase the purification component (5) cooperates to complete the introduction of clean air; Replace the module, run the ventilation system for half an hour, and then replace the filter. Remove the original supply and exhaust HEPA filters and replace them with new supply and exhaust HEPA filters. Testing was conducted to verify the integrity of the HEPA filter, using the PAO photometer method to determine if the HEPA filter was intact. The purification component (5) includes an inner liner (51), in which a positioning rod (55) is embedded. A cover plate (53) is installed on the upper end of the positioning rod (55). A guide plate (54) is installed on one side of the inner liner (51). The guide plate (54) is arc-shaped, and its top end covers the cover plate (53). The included angle between the cover plate (53) and the inner liner (51) is an acute angle. 1) Germicidal lamps (52) are connected to both sides of the included angle area on the inner liner (51) and the cover plate (53). A filter pad (56) is fixedly connected to the bottom end of the inner liner (51). A filter hole (57) is opened at the upper end of the filter pad (56). A filter sponge (58) is provided on the front side of the filter pad (56). The filter sponge (58) is embedded in the inner side of the germicidal lamp (52). The filter sponge (58) is made of transparent material. The filter sponge (58) is also provided with a hexagonal cavity inside. In the replacement module, the filter screen inside the filter box (43) is replaced, and the filter sponge (58) needs to be replaced at the same time. The filter sponge (58) is made of transparent material. The germicidal lamp (52) directly irradiates the inside of the filter sponge (58) with ultraviolet light. Air enters the inside of the filter sponge (58) and filters dust through the holes. The flow rate is relatively slow during the process. The ultraviolet light enters the inside of the filter sponge (58) to sterilize the bacteria and microorganisms inside. Then, the airflow is guided by the guide plate (54) and gradually penetrates upward. In the replacement process, it is taken out from the inside of the cover plate (53) and the inner liner seat (51). The new filter sponge (58) is inserted into the innermost side of the cover plate (53) and the inner liner seat (51) so that the filter sponge (58) is in close contact with the cover plate (53) and the filter hole (57).

2. The method for replacing the high-efficiency filter in a biosafety cabinet according to claim 1, characterized in that: The biosafety cabinet equipment includes a support base (1), an isolation cover (2) is installed on the top of the support base (1), the isolation cover (2) covers the upper surface of the support base (1), and an isolation door (3) is provided on one side of the front of the isolation cover (2). The isolation door (3) and the isolation cover (2) are movably connected, and the isolation door (3) is provided with a sealing gasket at the contact part with the upper surface of the support base (1).

3. The method for replacing the high-efficiency filter in a biosafety cabinet according to claim 1, characterized in that: The circulation assembly includes a delivery chamber (4), an exhaust pipe (42), an exhaust pipe (42), and a filter box (43). The circulation assembly participates in the introduction and delivery of outside air into the biosafety cabinet.

4. The method for replacing the high-efficiency filter in a biosafety cabinet according to claim 3, characterized in that: The conveying chamber (4) is installed inside the support base (1). A filter box (43) is installed at the top of the conveying chamber (4). The other end of the conveying pipe (41) embedded inside the conveying chamber (4) is embedded inside the filter box (43). The conveying chamber (4) and the filter box (43) are connected internally through the conveying pipe (41).

5. The method for replacing the high-efficiency filter in a biosafety cabinet according to claim 1, characterized in that: The power of the germicidal lamp (52) is 10 watts to 200 watts, and the ultraviolet radiation dose is 30-90 mJ / cm².

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