A disinfection ventilation system and disinfection method for a biosafety laboratory

Abstract

This invention discloses a disinfection and ventilation system and disinfection method for a biosafety laboratory. The system includes a laboratory room with a first exhaust HEPA filter and an supply HEPA filter installed on the ceiling. The supply HEPA filter is connected to an air outlet via a main supply duct. A fourth biosafety shut-off valve and an air supply unit are sequentially installed along the air supply direction on the main supply duct. The first exhaust HEPA filter is connected to an exhaust outlet via an exhaust duct. A first biosafety shut-off valve, a bag-in / bag-out HEPA filter, an exhaust unit, and a third biosafety shut-off valve are sequentially installed along the exhaust direction on the main exhaust duct. A first bypass duct connects the exhaust duct and the supply duct. The first and third bypass ducts provide a parallel connection for the first exhaust HEPA filter and the bag-in / bag-out HEPA filter, which are connected in series. This invention uses a parallel connection during disinfection, which effectively improves the disinfection effect of the bag-in / bag-out HEPA filter.

Description

Technical Field

[0001] This invention relates to the field of ventilation systems for biosafety laboratories, specifically to a disinfection ventilation system for a biosafety laboratory, and also to a disinfection method for such a system. Background Technology

[0002] High-level biosafety laboratories typically have ventilation systems equipped with both supply and exhaust HEPA filters. According to GB50346, "Technical Specification for Biosafety Laboratory Buildings," Level 3 biosafety laboratories may have two exhaust HEPA filters if there are special requirements. Level 4 biosafety laboratories, in addition to the first HEPA filter at the indoor exhaust vent, should have a second HEPA filter connected in series thereafter. Level 3 and Level 4 biosafety laboratories should be able to perform in-situ disinfection and leak detection of the exhaust HEPA filters, while Level 4 biosafety laboratories should be able to perform in-situ disinfection and leak detection of the supply HEPA filters. Therefore, Level 3 biosafety laboratories with special requirements may have two exhaust HEPA filters, while Level 4 biosafety laboratories must have two exhaust HEPA filters. Furthermore, Level 3 biosafety laboratories must perform in-situ disinfection of the exhaust HEPA filters, and Level 4 biosafety laboratories must perform in-situ disinfection of both the supply and exhaust HEPA filters.

[0003] Currently, according to regulations, some high-level biosafety laboratories have two exhaust HEPA filters in their ventilation systems. An outlet-type HEPA filter is installed near the exhaust vent, and a second-stage exhaust HEPA filter (bag-in / bag-out HEPA filter) is installed after the exhaust vents converge at the ductwork in the equipment layer. During terminal disinfection, a hydrogen peroxide disinfection device is introduced into the laboratory. This device continuously vaporizes liquid hydrogen peroxide. The vaporized hydrogen peroxide, under the operation of the ventilation system, penetrates the HEPA filter for disinfection. However, some hydrogen peroxide is intercepted during penetration, and the more HEPA filters there are, the worse the penetration effect. In practice, the disinfection effect is even more difficult to guarantee because the vaporized hydrogen peroxide is affected by ambient temperature and humidity. Disinfection of the bag-in / bag-out HEPA filters becomes a challenge. Therefore, some laboratories adopt another method: connecting each bag-in / bag-out HEPA filter to a separate hydrogen peroxide disinfection device for disinfection. However, some laboratories are large and have many bag-in / bag-out HEPA filters, making this disinfection method require significant manpower, resources, and time. Summary of the Invention

[0004] The purpose of this invention is to address the challenge of disinfecting two-stage exhaust HEPA filters in high-level biosafety laboratories by providing a disinfection and ventilation system for biosafety laboratories, and also providing a disinfection method for the disinfection and ventilation system of a biosafety laboratory.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A disinfection and ventilation system for a biosafety laboratory includes a laboratory room. A first exhaust HEPA filter and a supply HEPA filter are installed on the ceiling of the laboratory room. The supply HEPA filter is connected to an air outlet via a main supply duct. A fourth biosafety shut-off valve and a blower unit are sequentially installed along the air supply direction on the main supply duct. The first exhaust HEPA filter is connected to an exhaust outlet via an exhaust duct. A first biosafety shut-off valve, a bag-in / bag-out HEPA filter, an exhaust blower unit, and a third biosafety shut-off valve are sequentially installed along the exhaust direction on the main exhaust duct. One end of a first bypass duct is connected to a section of the main exhaust duct located between the exhaust blower unit and the third biosafety shut-off valve, and the other end is connected to… The main air supply duct section located between the air supply unit and the air supply HEPA filter is connected, and a fifth biosafety shut-off valve is installed on the first bypass duct; one end of the second bypass duct is connected to the main exhaust duct section located between the bag inlet / bag outlet HEPA filter and the exhaust fan unit, and the other end is connected to the main exhaust duct section located between the first exhaust HEPA filter and the first biosafety shut-off valve, and a second biosafety shut-off valve is installed on the second bypass duct; one end of the third bypass duct is connected to the main exhaust duct section located between the first biosafety shut-off valve and the bag inlet / bag outlet HEPA filter, and the other end is connected to the laboratory room, and a sixth biosafety shut-off valve is installed on the third bypass duct.

[0006] The main air supply duct is equipped with a disinfection interface, which is located between the connection point of the first bypass duct and the main air supply duct and the high-efficiency air supply filter.

[0007] A humidity sensor is installed on the top of the laboratory room, and a surface cooler is installed on the first bypass pipe, which is connected to a chiller unit.

[0008] An electric heater and a temperature sensor are installed on the first bypass pipe.

[0009] It also includes a hydrogen peroxide sensor and a differential pressure sensor. The hydrogen peroxide sensor is installed on the main exhaust duct, and the differential pressure sensor is installed on the ceiling of the laboratory room.

[0010] The laboratory room is equipped with a second exhaust HEPA filter at the top. The second exhaust HEPA filter is connected to a section of the main exhaust pipe located between the first exhaust HEPA filter and the first biosafety shut-off valve via an exhaust branch pipe.

[0011] The main exhaust duct is equipped with a first sampling port and a third sampling port. The first sampling port is near the exhaust end of the first exhaust HEPA filter, and the third sampling port is near the exhaust end of the bag-in-bag-out HEPA filter. The branch exhaust duct is equipped with a second sampling port.

[0012] The first, second, and third sampling ports each include a sampling tube and a fixing rod. The outlet end of the sampling tube is connected to the main exhaust pipe or the branch exhaust pipe. The inlet end of the sampling tube is provided with an internal thread. The fixing rod includes a storage basket connecting part, a connecting rod part, a threaded fixing part, and a sealing part connected in sequence along the axial direction. The storage basket connecting part is provided with a porous bacterial sheet storage basket. The threaded fixing part is provided with an external thread. The threaded fixing part is threadedly connected to the inlet end of the sampling tube. An O-ring is provided on the end face of the sealing part facing the sampling tube. When the threaded fixing part is screwed into the inlet end of the sampling tube and tightened, the O-ring is pressed between the outlet end face of the sampling tube and the end face of the sealing part.

[0013] When the threaded fixing part is screwed into the inlet end of the sampling tube and tightened, the porous bacterial tablet storage basket is located in the main exhaust pipe or the branch exhaust pipe.

[0014] A disinfection method for a disinfection and ventilation system in a biosafety laboratory, utilizing the aforementioned disinfection and ventilation system, includes the following steps: Step 1: Place the thermophilic Bacillus stearothermophilus bacterial tablets in the main exhaust duct through the first and third sampling ports, and place the thermophilic Bacillus stearothermophilus bacterial tablets in the branch exhaust duct through the second sampling port; Step 2: Close the third, fourth, sixth, and second biosafety valves, open the first and fifth biosafety valves, stop the supply fan unit, and start the exhaust fan unit for low-frequency operation. Step 3: Start the surface cooler to cool and dehumidify, maintaining the air humidity in the laboratory room at less than or equal to 55%. Use the electric heater to heat the indoor temperature of the laboratory room to 24~26℃, maintain this environmental condition for the set time, so that the temperature and humidity in the laboratory room are fully uniform. Then, turn off the surface cooler and the electric heater will switch to maintenance mode. Step 4: Connect the disinfection interface to the hydrogen peroxide disinfection equipment, and continuously inject the preset dose of hydrogen peroxide into the main air supply duct after it is vaporized by the hydrogen peroxide disinfection equipment. Step 5: When the hydrogen peroxide sensor detects that the hydrogen peroxide concentration is greater than the preset value, close the first biosafety valve and open the second and sixth biosafety valves. Step 6: When the differential pressure sensor detects that the value has reached the preset value, open the third biosafety airtight valve for a preset short time to release air and pressure. Step 7: After the preset dose of hydrogen peroxide has been injected, close the disinfection port; Step 8: After the preset disinfection time is reached, turn off the electric heater, the sixth biosafety shut-off valve, the second biosafety shut-off valve and the fifth biosafety shut-off valve in sequence, and then open the first biosafety shut-off valve, the third biosafety shut-off valve and the fourth biosafety shut-off valve in sequence, and restore the normal operation of the exhaust fan unit and the supply fan unit. Step 9: Take out thermophilic Bacillus stearothermophilus bacterial tablets from the first sampling port, the second sampling port, and the third sampling port respectively, and put each of the thermophilic Bacillus stearothermophilus bacterial tablets into a culture tube containing bromocresol purple peptone water medium. Place all culture tubes in a constant temperature incubator for incubation. After the incubation period, observe the results. If the medium remains purple, the sterilization is qualified. If the medium in any culture tube changes from purple to yellow, the sterilization fails. Step 10: If disinfection fails, replace the Bacillus stearothermophilus bacterial strip at the failed sampling port and repeat steps 2 to 9 until the culture medium remains purple.

[0015] Compared with the prior art, the present invention has the following advantages: 1. During the disinfection process, the series-connected vent-type HEPA filters and bag-in / bag-out HEPA filters are changed to a parallel connection. Hydrogen peroxide can more easily disinfect the bag-in / bag-out HEPA filters, while reducing the amount of hydrogen peroxide used. This saves manpower and time compared to disinfecting the bag-in / bag-out HEPA filters separately. When returning to normal operation, the vent-type HEPA filters and bag-in / bag-out HEPA filters can be immediately restored to a series connection, meeting national standards.

[0016] 2. A surface cooler and an electric heater are installed in the ventilation duct circulation disinfection loop. Before disinfection, the air humidity in the laboratory room and duct can be reduced to below 55%, and the temperature can be controlled at 24~26℃, so that the entire space reaches the optimal disinfection conditions of hydrogen peroxide, which is conducive to achieving the best disinfection effect.

[0017] 3. Installing a disinfection interface before the supply air HEPA filter allows for the disinfection of the supply air HEPA filter. Since the exhaust air HEPA filter poses a greater biosafety risk and is more difficult to disinfect successfully, the vaporized hydrogen peroxide first passes through the supply air HEPA filter and then penetrates the exhaust air HEPA filter. If the biological indicator sample (Bacillus stearothermophilus tablets) at the sampling port at the rear of the exhaust air HEPA filter passes disinfection, the supply and exhaust air HEPA filters can be considered disinfected successfully. Compared to placing the hydrogen peroxide disinfection equipment in a laboratory room to generate vaporized hydrogen peroxide (this method makes it difficult to arrange biological indicator samples to prove the supply air HEPA filter is disinfected successfully and cannot demonstrate whether hydrogen peroxide has penetrated the supply air HEPA filter), the disinfection results are more reliable.

[0018] 4. To avoid positive pressure during the disinfection process, the negative pressure state can be effectively maintained by briefly opening the exhaust biosafety sealing valve, thereby reducing the biosafety risks during the disinfection process.

[0019] 5. During the disinfection process, the electric heater is switched to maintenance mode to keep the ambient temperature at the optimal disinfection conditions, resulting in better disinfection and a higher success rate.

[0020] 6. By setting up the first and third sampling ports, the thermophilic Bacillus stearothermophilus bacterial sheets are placed in the main exhaust duct; by setting up the second sampling port, the thermophilic Bacillus stearothermophilus bacterial sheets are placed in the branch exhaust duct. This allows the thermophilic Bacillus stearothermophilus bacterial sheets to fully contact the vaporized hydrogen peroxide during disinfection, resulting in more accurate testing results. At the same time, the bacterial sheets are fixed in a porous bacterial sheet storage basket, solving the problem of the bacterial sheets being difficult to fix in the ventilation duct. Attached Figure Description

[0021] Figure 1 A schematic diagram of the ventilation system for disinfection in a biosafety laboratory; Figure 2 This is a schematic diagram of the sampling port structure; Among them, 1-Laboratory room; 2-Second exhaust HEPA filter; 3-First exhaust HEPA filter; 4-Second sampling port; 5-First sampling port; 6-First biosafety shut-off valve; 7-Second biosafety shut-off valve; 8-Bag-in-bag-out HEPA filter; 9-Third sampling port; 10-Exhaust fan unit; 11-Third biosafety shut-off valve; 12-Fourth biosafety shut-off valve; 13-Air supply fan unit; 14-Surface cooler; 15-Fifth biosafety shut-off valve; 16-Electric heater; 17-Temperature sensor; 18-Hydrogen peroxide sensor; 19- - Sixth biosafety shut-off valve; 20-Disinfection interface; 21-Differential pressure sensor; 22-Humidity sensor; 23-High-efficiency air supply filter; 24-Sampling tube; 25-Porous bacterial sheet storage basket; 26-Fixing rod; 27-O-ring seal; 101-Main air supply duct; 102-Main exhaust duct; 103-Branch exhaust duct; 104-First bypass duct; 105-Second bypass duct; 106-Third bypass duct; 2601-Storage basket connection part; 2602-Connecting rod part; 2603-Threaded fixing part; 2604-Sealing part. Detailed Implementation

[0022] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to implementation examples. It should be understood that the implementation examples described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1:

[0023] A disinfection and ventilation system for a biosafety laboratory includes a laboratory room 1. The top of the laboratory room 1 is equipped with a second exhaust air HEPA filter 2, a first exhaust air HEPA filter 3, a humidity sensor 22, and a supply air HEPA filter 23. The humidity sensor 22 is used to detect the humidity in the laboratory room 1, the supply air HEPA filter 23 is used to filter the incoming air of the laboratory room 1, and the second exhaust air HEPA filter 2 and the first exhaust air HEPA filter 3 serve as the first-stage exhaust air HEPA filters for filtering the exhaust air of the laboratory room 1.

[0024] The supply air HEPA filter 23 is connected to the air outlet through the main supply air duct 101. Along the air supply direction (air flows from the air outlet to the supply air HEPA filter 23), the main supply air duct 101 is sequentially equipped with a fourth biosafety shut-off valve 12 and an air supply unit 13. The first exhaust HEPA filter 3 is connected to the exhaust outlet through the main exhaust air duct 102. Along the exhaust direction (air flows from the first exhaust HEPA filter 3 to the exhaust outlet), the main exhaust air duct 102 is sequentially equipped with a first biosafety shut-off valve 6, a bag-in-bag-out HEPA filter 8, an exhaust unit 10, and a third biosafety shut-off valve 11. The bag-in-bag-out HEPA filter 8 serves as a second-stage exhaust HEPA filter for filtering the exhaust air from laboratory room 1. The second exhaust HEPA filter 2 is connected to the section of the main exhaust air duct 102 located between the first exhaust HEPA filter 3 and the first biosafety shut-off valve 6 through an exhaust branch duct 103, so that the second exhaust HEPA filter 2 and the first exhaust HEPA filter 3 are connected in parallel.

[0025] One end of the first bypass pipe 104 is connected to a section of the main exhaust pipe 102 located between the exhaust fan unit 10 and the third biosafety shut-off valve 11, and the other end of the first bypass pipe 104 is connected to a section of the main supply air pipe 101 located between the supply air fan unit 13 and the supply air high-efficiency filter 23, thereby connecting the main supply air pipe 101 and the first bypass pipe 104. A fifth biosafety shut-off valve 15 is installed on the first bypass pipe 104, which is used to control the opening and closing of the first bypass pipe 104.

[0026] One end of the second bypass pipe 105 is connected to a section of the main exhaust pipe 102 located between the bag inlet / outlet high-efficiency filter 8 and the exhaust fan unit 10, and the other end of the second bypass pipe 105 is connected to a section of the main exhaust pipe 102 located between the first exhaust high-efficiency filter 3 and the first biosafety shut-off valve 6. A second biosafety shut-off valve 7 is installed on the second bypass pipe 105.

[0027] One end of the third bypass pipe 106 is connected to the section of the main exhaust pipe 102 located between the first biosafety shut-off valve 6 and the bag-in-bag-out HEPA filter 8, and the other end of the third bypass pipe 106 is connected to the laboratory room 1. A sixth biosafety shut-off valve 19 is installed on the third bypass pipe 106.

[0028] When the third biosafety shut-off valve 11, the fourth biosafety shut-off valve 12, the sixth biosafety shut-off valve 19 and the second biosafety shut-off valve 7 are closed, the first biosafety shut-off valve 6 and the fifth biosafety shut-off valve 15 are opened, the supply fan unit 13 is stopped, and the exhaust fan unit 10 is turned on at low frequency, the air is in a closed internal circulation state between the laboratory room 1, the main exhaust duct 102, the first bypass duct 104 and the main exhaust duct 101, and the first-stage exhaust high-efficiency filter (first exhaust high-efficiency filter 2 and second exhaust high-efficiency filter 3) and the second-stage exhaust high-efficiency filter (bag inlet bag outlet high-efficiency filter 8) are connected in series.

[0029] When the third biosafety shut-off valve 11, the fourth biosafety shut-off valve 12, and the first biosafety shut-off valve 6 are closed, and the second biosafety shut-off valve 7, the sixth biosafety valve 19, and the fifth biosafety valve 15 are opened, the supply fan unit 13 is stopped, and the exhaust fan unit 10 is started at low frequency, the air is in a closed internal circulation state between the laboratory room 1, the main exhaust duct 102, the first bypass duct 104, and the main exhaust duct 101. The first-stage exhaust HEPA filter (first exhaust HEPA filter 2 and second exhaust HEPA filter 3) and the second-stage exhaust HEPA filter (bag-in-bag-out HEPA filter 8) are set in parallel. When hydrogen peroxide is used to disinfect through the ventilation system, the parallel setting of the first-stage exhaust HEPA filter and the second-stage exhaust HEPA filter can reduce the number of times hydrogen peroxide penetrates the exhaust HEPA filter during the disinfection process (two-stage penetration when connected in series, and same-stage penetration when connected in parallel).

[0030] In some embodiments, a surface cooler 14 is provided on the first bypass pipe 104. The surface cooler 14 is connected to a chiller unit and can achieve the purpose of cooling. Water vapor in the air will condense into water on the surface cooler 14 and be discharged, achieving the effect of dehumidification, thereby regulating the humidity of the laboratory room 1. The humidity of the laboratory room 1 can be detected by the humidity sensor 22, or the humidity of the laboratory room 1 can be regulated by the joint control of the surface cooler 14 and the humidity sensor 22.

[0031] In some embodiments, an electric heater 16 and a temperature sensor 17 are provided on the first bypass pipe 104. The electric heater 16 can heat the air in the first bypass pipe 104, and the temperature sensor 17 can detect the temperature of the air in the first bypass pipe 104. When the air is circulating, the temperature of the laboratory room 1 can be controlled by the cooperation of the electric heater 16 and the surface cooler 14.

[0032] In some embodiments, a disinfection interface 20 is provided on the main air supply duct 101. The disinfection interface 20 is located between the connection node of the first bypass duct 104 and the main air supply duct 101 and the high-efficiency air supply filter 23. During disinfection, the disinfection interface 20 is connected to vaporized hydrogen peroxide.

[0033] In some embodiments, the main exhaust duct 102 is provided with a first sampling port 5 and a third sampling port 9. The first sampling port 5 is near the exhaust end of the first exhaust HEPA filter 3, and the third sampling port 9 is near the exhaust end of the bag-in-bag-out HEPA filter 8. The branch exhaust duct 103 is provided with a second sampling port 4. During disinfection, thermophilic Bacillus stearothermophilus bacterial tablets are placed in the first sampling port 5, the second sampling port 4, and the third sampling port 9. After disinfection, the thermophilic Bacillus stearothermophilus bacterial tablets are tested to verify the disinfection effect.

[0034] Furthermore, such as Figure 2 As shown, the first sampling port 5, the second sampling port 4, and the third sampling port 9 each include a sampling tube 24 and a fixing rod 26. The outlet end of the sampling tube 24 is connected to the main exhaust pipe 102 or the branch exhaust pipe 103. The inlet end of the sampling tube 24 is provided with an internal thread. The fixing rod 26 includes a storage basket connecting part 2601, a connecting rod part 2602, a threaded fixing part 2603, and a sealing part 2604 connected sequentially along the axial direction. A multi-porous bacterial sheet storage basket 25 is provided on the storage basket connecting part 2601, and the threaded fixing part 2604 is provided with a sealing part 2604. The part 2603 is provided with an external thread, and the threaded fixing part 2603 is threadedly connected to the inlet end of the sampling tube 24 to realize the fixed connection between the fixing rod 26 and the sampling tube 24. The sealing part 2604 is provided with an O-ring 27 on the end face facing the sampling tube 24. When the threaded fixing part 2603 is screwed into the inlet end of the sampling tube 24 and tightened, the O-ring 27 is pressed between the outlet end face of the sampling tube 24 and the end face of the sealing part 2604 to achieve a reliable seal between the sampling tube 24 and the fixing rod 26.

[0035] Furthermore, the open end of the porous mycelium storage basket 25 is provided with an external thread, and the storage basket connecting part 2601 is provided with an internal thread. The open end of the porous mycelium storage basket 25 is threadedly connected to the storage basket connecting part 2601, so that the porous mycelium storage basket 25 is detachably fixedly installed on the storage basket connecting part 2601.

[0036] Furthermore, when the threaded fixing part 2603 is screwed into the inlet end of the sampling tube 24 and tightened, the porous bacterial sheet storage basket 25 is located in the main exhaust pipe 102 or the branch exhaust pipe 103.

[0037] Furthermore, the porous bacterial storage basket 25 is provided with several vent holes. The diameter of the vent holes is smaller than the diameter of the thermophilic Bacillus stearothermophilus bacterial sheet. The vent holes facilitate the penetration of hydrogen peroxide gas through the porous bacterial storage basket 25, while preventing the thermophilic Bacillus stearothermophilus bacterial sheet from being blown into the main exhaust duct 102 or the branch exhaust duct 103.

[0038] In some embodiments, a hydrogen peroxide sensor 18 is provided on the main exhaust duct 102. Along the exhaust direction of the main exhaust duct 102, the connection nodes between the main exhaust duct 102 and the branch exhaust duct 103, the installation point of the hydrogen peroxide sensor 18, and the connection node between the main exhaust duct 102 and the second bypass duct 105 located at the upstream end of the exhaust are arranged in sequence. The hydrogen peroxide sensor 18 can detect the concentration of hydrogen peroxide during disinfection.

[0039] In some embodiments, a differential pressure sensor 21 is installed on the top of the laboratory room 1. The differential pressure sensor 21 is used to detect whether the laboratory room 1 is under negative pressure. During the disinfection process, hydrogen peroxide decomposes into water and oxygen, causing the pressure inside the laboratory room 1 to rise. When the value of the differential pressure sensor 21 is less than a preset value, the third biosafety airtight valve 11 needs to be opened for a preset time to release some air, so that the laboratory room 1 is under negative pressure. Example 2:

[0040] This invention also provides a disinfection method for a disinfection and ventilation system in a biosafety laboratory, utilizing the disinfection and ventilation system for a biosafety laboratory described in Example 1, comprising the following steps: Step 1: Place the thermophilic Bacillus stearothermophilus bacterial tablets in the main exhaust duct 102 through the first sampling port 5 and the third sampling port 9, and place the thermophilic Bacillus stearothermophilus bacterial tablets in the branch exhaust duct 103 through the second sampling port 4.

[0041] Specifically: The thermophilic Bacillus stearothermophilus bacterial tablets are placed into the porous bacterial tablet storage baskets 25 corresponding to the first sampling port 5, the second sampling port 4, and the third sampling port 9, respectively, and the porous bacterial tablet storage baskets 25 are installed on the storage basket connecting parts 2601 of the corresponding fixing rods 26; the threaded fixing parts 2603 of each fixing rod 26 are screwed into the inlet end of the corresponding sampling tube 24 and tightened, so that the O-ring 27 is pressed between the inlet end face of the sampling tube 24 and the end face of the sealing part 2604, thereby achieving a seal between the fixing rod 26 and the sampling tube 24. At the same time, the thermophilic Bacillus stearothermophilus bacterial tablets are placed in the main exhaust duct 102 through the first sampling port 5 and the third sampling port 9, and the thermophilic Bacillus stearothermophilus bacterial tablets are placed in the branch exhaust duct 103 through the second sampling port 4.

[0042] Step 2: Close the third biosafety shut-off valve 11, the fourth biosafety shut-off valve 12, the sixth biosafety shut-off valve 19, and the second biosafety shut-off valve 7; open the first biosafety shut-off valve 6 and the fifth biosafety shut-off valve 15; stop the supply fan unit 13; and start the exhaust fan unit 10 at low frequency to keep the laboratory room and ventilation system duct in a closed loop (at this time, the first-stage exhaust HEPA filter and the second-stage exhaust HEPA filter are connected in series).

[0043] Step 3: Activate the surface cooler 14 to cool and dehumidify, maintaining the air humidity in laboratory room 1 at less than or equal to 55%. Use the electric heater 16 to heat the indoor temperature of laboratory room 1 to 24~26℃ and maintain this environmental condition for 10 minutes to ensure that the temperature and humidity in all parts of laboratory room 1 are fully uniform. Then, turn off the surface cooler 14 and switch the electric heater 16 to the maintenance mode to ensure that the ambient temperature is in a suitable temperature range during the disinfection process. Under this environmental condition, the disinfection effect of hydrogen peroxide can reach the best state.

[0044] Step 4: Connect the disinfection interface 20 to the hydrogen peroxide disinfection device (VHP), and continuously inject the preset dose of hydrogen peroxide into the main air supply duct 101 after vaporization by the hydrogen peroxide disinfection device.

[0045] Step 5: When the hydrogen peroxide sensor 18 detects that the hydrogen peroxide concentration is greater than the preset value, close the first biosafety shut-off valve 6 and open the second biosafety shut-off valve 7 and the sixth biosafety shut-off valve 19. This changes the parallel connection between the second exhaust HEPA filter 2 and the first exhaust HEPA filter 3 and the bag inlet / outlet HEPA filter 8 from a series mode to a parallel mode, making it easier for the vaporized hydrogen peroxide to penetrate the bag inlet / outlet HEPA filter 8.

[0046] Step 6: The differential pressure sensor 21 continuously monitors the differential pressure between laboratory room 1 and the surrounding environment. Since hydrogen peroxide is easily decomposed into water and oxygen, positive pressure is easily generated during the room disinfection process. In order to reduce biosafety risks, when the differential pressure sensor 21 detects that the value reaches the preset value (less than 15 Pa), the third biosafety airtight valve 11 is opened for a preset short time (about 3 seconds) to release the pressure and ensure that no positive pressure is generated during the disinfection process.

[0047] Step 7: After the preset dose of hydrogen peroxide has been injected, close the disinfection port 20.

[0048] Step 8: After the preset disinfection time (approximately three hours) is reached, turn off the electric heater 16, the sixth biosafety shut-off valve 19, the second biosafety shut-off valve 7, and the fifth biosafety shut-off valve 15 in sequence. Then, turn on the first biosafety shut-off valve 6, the third biosafety shut-off valve 11, and the fourth biosafety shut-off valve 12 in sequence, and restore the normal operation of the exhaust fan unit 10 and the supply fan unit 13. The disinfection and ventilation system will switch from the disinfection state to the ventilation state to remove the residual hydrogen peroxide in the laboratory room 1.

[0049] Step 9: Take out thermophilic Bacillus stearothermophilus bacterial tablets from the first sampling port 5, the second sampling port 4, and the third sampling port 9 respectively (operate under aseptic conditions), and put each thermophilic Bacillus stearothermophilus bacterial tablet into a culture tube containing bromocresol purple peptone water medium. Place all culture tubes in a 56℃ constant temperature incubator for incubation. After the incubation period (7 days), observe the results. If the medium remains purple, the sterilization is qualified. If the medium in any culture tube changes from purple to yellow, the sterilization fails.

[0050] Step 10: If disinfection fails, simply replace the thermophilic Bacillus stearothermophilus bacterial strip at the failed sampling port and repeat steps 2 to 9 until the culture medium remains purple.

[0051] Under normal circumstances, the disinfection method described in this application requires testing the amount of hydrogen peroxide needed for disinfection based on factors such as room size and pipe length, and disinfection should be carried out according to the established parameters, which can effectively improve the disinfection success rate.

[0052] It should be noted that the embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A disinfection and ventilation system for a biosafety laboratory, comprising a laboratory room (1), characterized in that, The laboratory room (1) is equipped with a first exhaust HEPA filter (3) and an air supply HEPA filter (23) on the top. The air supply HEPA filter (23) is connected to the air outlet through the main air supply pipe (101). The main air supply pipe (101) is equipped with a fourth biosafety shut-off valve (12) and an air supply unit (13) in sequence along the air supply direction. The first exhaust HEPA filter (3) is connected to the exhaust outlet through the main exhaust pipe (102). The main exhaust pipe (102) is equipped with a first biosafety shut-off valve (6), a bag-in-bag-out HEPA filter (8), an exhaust unit (10), and a third biosafety shut-off valve (11) in sequence along the exhaust direction. One end of the first bypass pipe (104) is connected to the section of the main exhaust pipe (102) located between the exhaust unit (10) and the third biosafety shut-off valve (11), and the other end is connected to the section of the main exhaust pipe (102) located between the air supply unit (13) and the air supply HEPA filter. The main air supply pipe (101) between the devices (23) is connected to the pipe section, and the first bypass pipe (104) is equipped with a fifth biosafety shut-off valve (15); one end of the second bypass pipe (105) is connected to the pipe section of the main exhaust pipe (102) between the bag inlet / outlet HEPA filter (8) and the exhaust fan unit (10), and the other end is connected to the pipe section of the main exhaust pipe (102) between the first exhaust HEPA filter (3) and the first biosafety shut-off valve (6), and the second bypass pipe (105) is equipped with a second biosafety shut-off valve (7); one end of the third bypass pipe (106) is connected to the pipe section of the main exhaust pipe (102) between the first biosafety shut-off valve (6) and the bag inlet / outlet HEPA filter (8), and the other end is connected to the laboratory room (1), and the third bypass pipe (106) is equipped with a sixth biosafety shut-off valve (19).

2. The disinfection and ventilation system for a biosafety laboratory according to claim 1, characterized in that, The main air supply duct (101) is provided with a disinfection interface (20), which is located between the connection node of the first bypass duct (104) and the main air supply duct (101) and the high-efficiency air supply filter (23).

3. The disinfection and ventilation system for a biosafety laboratory according to claim 2, characterized in that, A humidity sensor (22) is installed on the top of the laboratory room (1), and a surface cooler (14) is installed on the first bypass pipe (104), which is connected to the chiller unit.

4. The disinfection and ventilation system for a biosafety laboratory according to claim 3, characterized in that, An electric heater (16) and a temperature sensor (17) are provided on the first bypass pipe (104).

5. A disinfection and ventilation system for a biosafety laboratory according to claim 4, characterized in that, It also includes a hydrogen peroxide sensor (18) and a differential pressure sensor (21), with the hydrogen peroxide sensor (18) installed on the main exhaust duct (102) and the differential pressure sensor (21) installed on the top of the laboratory room (1).

6. The disinfection and ventilation system for a biosafety laboratory according to claim 5, characterized in that, The laboratory room (1) is equipped with a second exhaust high-efficiency filter (2) at the top. The second exhaust high-efficiency filter (2) is connected to the section of the main exhaust pipe (102) located between the first exhaust high-efficiency filter (3) and the first biosafety shut-off valve (6) through an exhaust branch pipe (103).

7. A disinfection and ventilation system for a biosafety laboratory according to claim 6, characterized in that, The main exhaust pipe (102) is provided with a first sampling port (5) and a third sampling port (9). The first sampling port (5) is close to the exhaust end of the first exhaust high-efficiency filter (3), and the third sampling port (9) is close to the exhaust end of the bag inlet and bag outlet high-efficiency filter (8). The branch exhaust pipe (103) is provided with a second sampling port (4).

8. A disinfection and ventilation system for a biosafety laboratory according to claim 7, characterized in that, The first sampling port (5), the second sampling port (4), and the third sampling port (9) all include a sampling tube (24) and a fixing rod (26). The outlet end of the sampling tube (24) is connected to the main exhaust pipe (102) or the branch exhaust pipe (103). The inlet end of the sampling tube (24) is provided with an internal thread. The fixing rod (26) includes a storage basket connecting part (2601), a connecting rod part (2602), a threaded fixing part (2603), and a sealing part (2604) connected in sequence along the axial direction. The sample tube (24) is provided with a porous substrate storage basket (25) and a threaded fixing part (2603) with an external thread. The threaded fixing part (2603) is threadedly connected to the inlet end of the sampling tube (24). An O-ring (27) is provided on the end face of the sealing part (2604) facing the sampling tube (24). When the threaded fixing part (2603) is screwed into the inlet end of the sampling tube (24) and tightened, the O-ring (27) is pressed between the outlet end face of the sampling tube (24) and the end face of the sealing part (2604).

9. A disinfection and ventilation system for a biosafety laboratory according to claim 8, characterized in that, When the threaded fixing part (2603) is screwed into the inlet end of the sampling tube (24) and tightened, the porous bacterial sheet storage basket (25) is located in the main exhaust pipe (102) or the branch exhaust pipe (103).

10. A disinfection method for a disinfection and ventilation system in a biosafety laboratory, utilizing the disinfection and ventilation system for a biosafety laboratory as described in claim 7, characterized in that, Includes the following steps: Step 1: Place the thermophilic Bacillus stearothermophilus bacterial tablets in the main exhaust pipe (102) through the first sampling port (5) and the third sampling port (9), and place the thermophilic Bacillus stearothermophilus bacterial tablets in the branch exhaust pipe (103) through the second sampling port (4); Step 2: Close the third biosafety shut-off valve (11), the fourth biosafety shut-off valve (12), the sixth biosafety shut-off valve (19), and the second biosafety shut-off valve (7); open the first biosafety shut-off valve (6) and the fifth biosafety shut-off valve (15); stop the blower unit (13); and start the exhaust fan unit (10) for low-frequency operation. Step 3: Start the surface cooler (14) to cool and dehumidify, and maintain the air humidity in the laboratory room (1) at less than or equal to 55%. Heat the indoor temperature of the laboratory room (1) to 24~26℃ by the electric heater (16), and maintain this environmental condition for a set time to make the temperature and humidity in the laboratory room (1) fully uniform. Then, turn off the surface cooler (14) and the electric heater (16) enters the maintenance mode. Step 4: Connect the disinfection interface (20) to the hydrogen peroxide disinfection device, and continuously inject the preset dose of hydrogen peroxide into the main air supply duct (101) after it is vaporized by the hydrogen peroxide disinfection device. Step 5: When the hydrogen peroxide sensor (18) detects that the hydrogen peroxide concentration is greater than the preset value, close the first biosafety shut-off valve (6) and open the second biosafety shut-off valve (7) and the sixth biosafety shut-off valve (19). Step 6: When the differential pressure sensor (21) detects that the value has reached the preset value, the third biosafety airtight valve (11) is opened for a preset short time to release air pressure. Step 7: After the preset dose of hydrogen peroxide has been injected, close the disinfection port (20). Step 8: After the preset disinfection time is reached, turn off the electric heater (16), the sixth biosafety shut-off valve (19), the second biosafety shut-off valve (7) and the fifth biosafety shut-off valve (15) in sequence, and then turn on the first biosafety shut-off valve (6), the third biosafety shut-off valve (11) and the fourth biosafety shut-off valve (12) in sequence, and restore the normal operation of the exhaust fan unit (10) and the supply fan unit (13); Step 9: Take out thermophilic Bacillus stearothermophilus bacterial tablets from the first sampling port (5), the second sampling port (4), and the third sampling port (9), and put each thermophilic Bacillus stearothermophilus bacterial tablet into a culture tube containing bromocresol purple peptone water medium. Place all culture tubes in a constant temperature incubator for incubation. Observe the results after the incubation period. If the medium remains purple, the disinfection is qualified. If the medium in any culture tube changes from purple to yellow, the disinfection fails. Step 10: If disinfection fails, replace the Bacillus stearothermophilus bacterial strip at the failed sampling port and repeat steps 2 to 9 until the culture medium remains purple.

Images