Method for detecting air tightness and leakage points of cage box of IVC experimental animal independent ventilation cage system

Abstract

The invention relates to a method for detecting air tightness and leakage points of a cage box of an IVC experimental animal independent ventilation cage system, and belongs to the field of laboratory equipment in the biomedical field. The method comprises the following steps: adopting a cage box taken from an IVC experimental animal independent ventilation cage system as a detection cage box; two air guide parts are arranged on the box body, and each air guide part comprises an air receiving section; during detection, the box cover of the detection cage box is taken down, and the box cover of the cage box of which the air tightness is to be detected is taken down and then mounted on the box body of the detection cage box; wherein one gas receiving section is connected with a pressure detector which is qualified through calibration and measurement, the other gas receiving section is connected with a negative pressure pumping device, and a new cage box to be detected is vacuumized to-100 Pa through the negative pressure pumping device; if the time for attenuating the pressure in the cage box to be detected from-100 Pa to 0 Pa is not less than 5 min, the air tightness is qualified, and otherwise, the air tightness is unqualified. And for unqualified box covers, leakage points can be rapidly detected. The method is simple, convenient, rapid and accurate to operate.

Description

Technical Field

[0001] The present application relates to the field of laboratory equipment in the biomedical field, and in particular to a method for detecting the air tightness and leaks of cage boxes of an independent ventilation cage system for IVC experimental animals. Background Art

[0002] IVC (Independent Ventilation Cage) systems for laboratory animals are key equipment in the field of laboratory animal research. They are primarily used for the isolated and ventilated housing of small animals, such as rats and mice, to reduce the risk of cross-infection and ensure animal welfare. The system typically includes a processing unit, cage racks, cage boxes, and air supply and exhaust ducts. The cage boxes are arranged on the racks, with the air inlet of each box connected to the air supply duct, and the air outlet of each box connected to the exhaust duct.

[0003] According to the National Laboratory Animal Environmental Standard GB17925-2010, there are clear parameter and indicator requirements for the laboratory animal environment. Furthermore, the Technical Specification for Biosafety Performance Evaluation of Laboratory Equipment (RB / T 199-2015) requires that independent ventilation cage (IVC) testing be conducted at least during the following times: 1. After installation and before commissioning; 2. After replacing HEPA filters or repairing internal components; and 3. Annual maintenance inspections. On-site inspections should at least include airflow velocity, pressure differential, air change rate, cage air tightness, and leak testing of HEPA supply and exhaust filters.

[0004] Specifically, national standards require that the cage be kept at a negative pressure of -100 Pa (internal pressure) for 5 minutes, without the negative pressure dropping to 0 Pa. IVC (independently ventilated animal cage) systems are prone to poor air tightness after a period of operation. Therefore, it is crucial for operators to easily, efficiently, and accurately determine the air tightness of cages.

[0005] Existing methods for testing the air tightness of cages in IVC (independent ventilation) cage systems are cumbersome and inconvenient, and they cannot quickly and accurately assess the air tightness of cages. Furthermore, existing methods cannot quickly identify leaks based on the test results. Summary of the Invention

[0006] In order to solve or partially solve the problems existing in the related art, the present application provides a method for detecting the air tightness and leak points of cage boxes of IVC experimental animal independent ventilation cage systems. The method is simple to operate and can quickly and accurately detect and judge the air tightness of cage boxes; at the same time, for cage boxes that are judged to be unqualified for air tightness, the location of the leak point can also be quickly detected.

[0007] The present application discloses a method for detecting air tightness and leaks of cages in an IVC experimental animal independent ventilation cage system, comprising using a cage from the IVC experimental animal independent ventilation cage system as a test cage for testing; The detection cage box is composed of a box body and a detachably connected box cover; two air guides are provided on one surface of the box body through the box wall for connecting the inside and outside of the box body, and the air guides include an air connection section extending toward the outside of the box body; During the test, the box cover of the test cage is removed, and the box cover of the cage to be tested for air tightness is removed and then installed on the box body of the test cage, thereby forming a new cage to be tested; The air tightness test is performed on the new cage box to be tested, specifically: one of the air connection sections is connected to a calibrated and qualified pressure tester, and the other air connection section is connected to a negative pressure pumping device, and the new cage box to be tested is vacuumed to -100Pa by the negative pressure pumping device; if the time for the pressure in the cage box to be tested to decay from -100Pa to 0Pa is not less than 5min, it means that the air tightness is qualified, otherwise, the air tightness is unqualified; for the cage box that fails to pass the air tightness test after the test, the cage box is placed in a water tank and the negative pressure pumping device connected to the air connection section (300) is replaced with a positive pressure blowing device, and positive pressure is blown into the new cage box to be tested to 150-200Pa by the positive pressure device, and then the cage box is observed where bubbles are generated in the water tank to determine the location of the cage box leakage; Alternatively, spray bubbling water on the outer surface of the cage box that does not meet the airtightness requirements and observe whether bubbles are generated to determine the location of the cage box leak.

[0008] Specifically, the air guide part includes a hollow air guide tube and a sealing disk, and the part of the hollow air guide tube extending to the outside of the box body constitutes an air connection section; the hollow air guide tube is arranged through the sealing disk and the hollow air guide tube and the sealing disk are sealed and fixedly connected; the end face of the sealing disk facing the box body is sealed and fixedly connected to the outer side surface of the box body.

[0009] The beneficial effects of this application are: 1. Testing the air tightness of cages in IVC experimental animal independent ventilation cage systems is a difficult problem in itself. After extensive data statistics, the inventors found that the main components affecting the air tightness of the cages are the rubber sealing ring on the lid and the one-way valves at the air supply and exhaust ports (both located on the cage lid). When using the test cage of the present application for testing, it is only necessary to remove the lid of the cage to be tested in the IVC experimental animal independent ventilation cage system and replace it with the test cage. Then, a calibrated and qualified pressure tester is connected to one of the air connection sections, and a negative pressure pumping device is connected to the other air connection section. The new cage to be tested is evacuated to -100 Pa by the negative pressure pumping device. If the time for the pressure in the cage to be tested to decay from -100 Pa to 0 Pa is not less than 5 minutes, it is considered to be airtight. Otherwise, the airtightness is unqualified and the airtightness test can be carried out. This testing method effectively solves the problem of cage airtightness testing in the prior art and is simple to operate, fast and accurate.

[0010] 2. In this application, based on the results of the air tightness test, for cage boxes that fail the air tightness test, the cage boxes are placed in a water tank and the negative pressure device connected to the air connection section is replaced with a positive pressure blowing device. The positive pressure device is used to blow positive pressure to 150-200 Pa into the new cage box to be tested, and then observe where bubbles are generated in the water tank to determine the location of the cage box leak; or spray bubbling water on the outer surface of the cage box that fails the air tightness test to observe whether bubbles are generated to determine the location of the cage box leak; by detecting the location of the leak, the parts that need to be replaced can be found in a targeted manner instead of discarding the entire cage box, thereby saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0012] Figure 1 It is a left-side structural schematic diagram of the detection cage box in this application; Figure 2 This is a schematic diagram of the main structure of the detection cage box in this application; Figure 3 It is a structural diagram of the air guide part in this application. DETAILED DESCRIPTION

[0013] The embodiments of the present application will be described in more detail below with reference to the examples. Although the embodiments of the present application are shown in the examples, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0014] Example In this embodiment, a method for testing air tightness and leaks in cages of an IVC experimental animal independent ventilation cage system includes using a cage from the IVC experimental animal independent ventilation cage system as a test cage for testing. The detection cage box is composed of a box body 1 and a detachably connected box cover 2; two air guides 3 are provided on one surface of the box body 1 through the box wall for connecting the inside and outside of the box body, and the air guides 3 include an air connection section 300 extending toward the outside of the box body; During the test, the box cover of the test cage is removed, and the box cover of the cage to be tested for air tightness is removed and then installed on the box body of the test cage, thereby forming a new cage to be tested; Specifically, the IVC experimental animal independent ventilation cage system in this embodiment is produced by TECNIPLAST SPA, model TYPE 21SO72, serial number SN 1210408; When performing an air tightness test on the new cage box to be tested, specifically: one of the air connecting sections 300 is connected to a calibrated and qualified pressure tester, and the other air connecting section 300 is connected to a negative pressure pumping device, and the new cage box to be tested is evacuated to -100 Pa through the negative pressure pumping device; if the time for the pressure in the cage box to be tested to decay from -100 Pa to 0 Pa is not less than 5 minutes, it means that the air tightness is qualified; otherwise, the air tightness is unqualified.

[0015] Furthermore, for cages that fail the airtightness test, place the cage in a water tank and replace the negative pressure device connected to the air connection section 300 with a positive pressure blowing device. Use the positive pressure device to blow positive pressure to 150-200 Pa into the new cage to be tested. Then observe where bubbles are generated in the cage in the water tank to determine the location of the cage leak. Alternatively, spray bubbling water on the outer surface of the cage box that does not meet the airtightness requirements and observe whether bubbles are generated to determine the location of the cage box leak.

[0016] In practice, it is found that the main components that affect the air tightness of the cage box are the rubber sealing ring on the cage box cover and the one-way valve of the air supply and exhaust vents. Therefore, the corresponding parts can be replaced in a targeted manner according to the air tightness test results.

[0017] Specifically, the air guide part 3 includes a hollow air guide tube 30 and a sealing disk 31. The part of the hollow air guide tube 30 extending to the outside of the box body constitutes an air connection section 300; the hollow air guide tube 30 is arranged to pass through the sealing disk 31 and the hollow air guide tube 30 and the sealing disk 31 are sealed and fixedly connected; the end face of the sealing disk 31 facing the box body is sealed and fixedly connected to the outer side surface of the box body.

[0018] The function of the air guide part 3 is to connect with the pressure detector and the negative pressure extraction device conveniently and quickly; specifically, the air guide part 3 in this embodiment specifically selects the pressure guide nozzle / air guide nozzle in the existing technology, for example, the pressure guide nozzle / air guide nozzle produced by Shijiazhuang Mingle Mechanical and Electrical Equipment Sales Co., Ltd.

[0019] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for detecting air tightness and leaks in cages of an IVC experimental animal independent ventilation cage system, characterized by: This includes using a cage from the IVC laboratory animal independent ventilation cage system as a test cage for testing; The detection cage box is composed of a box body (1) and a detachably connected box cover (2); two air guides (3) for connecting the inside and outside of the box body are provided on one surface of the box body (1) through the box wall, and the air guides (3) include an air connection section (300) extending toward the outside of the box body; During the test, the box cover of the test cage is removed, and the box cover of the cage to be tested for air tightness is removed and then installed on the box body of the test cage, thereby forming a new cage to be tested; The air tightness test is performed on the new cage box to be tested, specifically: one of the air connection sections (300) is connected to a calibrated and qualified pressure tester, and the other air connection section (300) is connected to a negative pressure pumping device, and the new cage box to be tested is evacuated to -100 Pa by the negative pressure pumping device; if the time for the pressure in the cage box to be tested to decay from -100 Pa to 0 Pa is not less than 5 minutes, it is indicated that the air tightness is qualified, otherwise, the air tightness is unqualified; For the cage box that fails the air tightness test, the cage box is placed in a water tank and the negative pressure device connected to the air connection section (300) is replaced with a positive pressure blowing device. The positive pressure device is used to blow positive pressure to 150-200 Pa into the new cage box to be tested. Then, the position where bubbles are generated in the cage box in the water tank is observed to determine the location of the cage box leakage. Alternatively, spray bubbling water on the outer surface of the cage box that does not meet the airtightness requirements and observe whether bubbles are generated to determine the location of the cage box leak.

2. A method for detecting air tightness and leaks in an IVC experimental animal independent ventilation cage system according to claim 1, characterized in that: The air guide portion (3) comprises a hollow air guide tube (30) and a sealing disk (31); the portion of the hollow air guide tube (30) extending toward the outside of the box body constitutes an air connection section (300); the hollow air guide tube (30) is arranged to pass through the sealing disk (31), and the hollow air guide tube (30) and the sealing disk (31) are sealed and fixedly connected; the end surface of the sealing disk (31) facing the box body is sealed and fixedly connected to the outer side surface of the box body.

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