Method for detecting air tightness of tobacco leaf storage elevated warehouse

Abstract

The invention relates to the technical field of controlled atmosphere storage, in particular to a method for detecting the air tightness of a tobacco storage elevated warehouse, which adopts a differential pressure method to detect the negative pressure half-life period in a sealed tent of the tobacco storage elevated warehouse, the lower limit of test negative pressure is greater than or equal to the negative pressure limit value of the sealed tent, and the absolute value of the upper limit of test negative pressure is equal to the absolute value of the lower limit of test negative pressure * 1 / 2. The negative pressure half-life period is greater than or equal to 60 minutes. Preferably, the lower limit of the test negative pressure is-50Pa, the corresponding upper limit of the test negative pressure is-25Pa, and the half-life period of the negative pressure is greater than or equal to 97 minutes. The method for detecting the air tightness of the tobacco leaf storage elevated warehouse is easy to operate, the air tightness of the sealed tent of the elevated warehouse is judged by detecting and analyzing the maintenance condition of the sealed tent of the elevated warehouse in the low-oxygen environment within 7 days and verifying the negative pressure half-life period through a differential pressure method, the method is scientific and feasible, the detection efficiency is high, and the method is suitable for popularization and application. And the problem that a traditional warehousing space airtightness detection method is not suitable for airtightness detection of the tobacco leaf storage elevated warehouse is solved.

Description

Technical Field

[0001] The invention relates to the technical field of controlled atmosphere storage, and in particular to a method for detecting the air tightness of a tobacco leaf storage high-rise warehouse during controlled atmosphere storage and curing of tobacco leaves. Background Art

[0002] The common controlled atmosphere storage method is a controlled atmosphere storage and maintenance technology that controls the storage environment of tobacco leaves in a low oxygen state throughout the aging cycle, kills tobacco storage pests and inhibits mold, thereby achieving pest control, mildew prevention and control and maintaining the quality of tobacco leaves. The existing inspection of the sealing of tobacco stacks usually uses a combination of visual inspection and oxygen concentration detection to inspect the sealing of the stacks. In the early stage of stack sealing, if the seal is intact, the film should be close to the tobacco box. If the film is visually loose, it is necessary to detect the oxygen concentration in the stack to determine whether it is leaking. However, this method has a certain hysteresis, especially when used in tobacco leaf storage high-rise warehouses, which will affect the efficiency and effect of controlled atmosphere pest control of tobacco leaves. Secondly, "GB / T 25229-2010 Requirements for Air Tightness of Flat Warehouses for Grain and Oil Storage" discloses that the air tightness of flat warehouses is divided into three levels based on the pressure half-life of 500 Pa; the air tightness of grain piles sealed by films in flat warehouses is divided into two levels based on the pressure half-life of 300 Pa.

[0003]

[0004] Since the storage volume of the tobacco leaf storage high-rise warehouse is large and the sealed tent is made of a film with low oxygen permeability, when the air tightness is measured by negative pressure, the film of the sealed tent cannot withstand a large negative pressure like the film sealing device in the flat warehouse under its own gravity and the force generated between it and the support frame. Therefore, the above detection method cannot meet the detection needs of the air tightness of the existing tobacco leaf storage high-rise warehouse, and it is urgent to find a new and easy-to-implement method for detecting the air tightness of tobacco leaf storage high-rise warehouses. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method which is simple to operate and easy to implement and is suitable for detecting the air tightness of a tobacco leaf storage elevated warehouse.

[0006] The technical solution adopted by the present invention to solve its technical problem is: A method for detecting the air tightness of a tobacco leaf storage high-rise warehouse, using a pressure difference method to detect the negative pressure half-life in a sealed tent of the tobacco leaf storage high-rise warehouse, and the test negative pressure lower limit ≥ the negative pressure limit value of the sealed tent, the absolute value of the test negative pressure upper limit = the absolute value of the test negative pressure lower limit * 1 / 2, and the negative pressure half-life ≥ 60min.

[0007] The lower limit of the test negative pressure ranges from -60Pa to -30Pa.

[0008] Based on experimental analysis, it is concluded that the positive pressure limit of the sealed tent of the tobacco leaf storage high-rise warehouse is relatively small, and is not suitable for the pressure difference method to obtain an effective pressure half-life, and its negative pressure limit is much lower than the negative pressure limit of the sealed tent of the existing ordinary floor warehouse or small stack in the bungalow warehouse. The applicant has determined the lower limit and upper limit of the test negative pressure of the sealed tent of the tobacco leaf storage high-rise warehouse suitable for the pressure difference method detection through repeated tests, and further verified the negative pressure half-life obtained by the above pressure difference method test as an indicator for determining the air tightness of the tobacco leaf storage high-rise warehouse through the change of oxygen concentration in the sealed tent of the tobacco leaf storage high-rise warehouse in a low-oxygen environment within 7 days. When the negative pressure half-life is ≥60min, in the air tightness verification test, the oxygen content in the sealed tent of the tobacco leaf storage high-rise warehouse can remain in a low oxygen state (O2<2%) for more than 45 days. In actual production applications, it can fully meet the air tightness requirements of nitrogen fumigation, thereby solving the problem of air tightness detection of tobacco leaf storage high-rise warehouses and significantly shortening the air tightness detection cycle of tobacco leaf storage high-rise warehouses.

[0009] A method for detecting the air tightness of a tobacco leaf storage high-bay warehouse, comprising: S1 determines the negative pressure half-life of the sealed tent: start the exhaust fan to slowly exhaust air so that the sealed tent reaches the lower limit of the negative pressure test, and the detection value of the lower limit of the negative pressure test is ≥ the negative pressure limit value measured by S2. After the pressure in the sealed tent is balanced, start timing, and detect the pressure of the sealed tent every 1 to 3 minutes until the pressure of the sealed tent rises to the upper limit of the negative pressure test, and the absolute value of the upper limit of the negative pressure test = the absolute value of the lower limit of the negative pressure test * 1 / 2, stop timing, and get the negative pressure half-life t; S2 Air tightness determination: if the negative pressure half-life t measured by S3 is ≥ 60min, the air tightness of the sealed tent of the tobacco leaf storage high-rise warehouse meets the requirements for tobacco leaf storage, otherwise, it does not meet the requirements.

[0010] Among them, the maximum negative pressure that the sealed tent can withstand is -60Pa.

[0011] It should be noted that, as the sealing curtain film of the tobacco leaf storage high-bay warehouse increases with the height of the high-bay warehouse, its own gravity will increase the force between the film and the metal shelves / support rods of the high-bay warehouse. Therefore, the negative pressure limit that the sealing curtain can withstand is much greater than the negative pressure limit of the sealing curtain of the flat warehouse. On the premise of ensuring the sealing performance of the sealing curtain itself, the applicant has verified through multiple tests that the negative pressure limit of the sealing curtain of the existing tobacco leaf storage high-bay warehouse is -60Pa.

[0012] In a certain exemplary embodiment, the pressure detection range corresponding to the negative pressure half-life in S1 is -60Pa ~ -15Pa.

[0013] It should be noted that the smaller the absolute value of the upper limit of the negative pressure in the differential pressure method, the longer the negative pressure half-life is, and as the upper limit of the negative pressure decreases, the change of the negative pressure half-life gradually decreases and tends to be gentle (such as Figure 1 , 2 As shown); in addition, since the storage area of ​​the tobacco leaf storage high-rise warehouse is large, and the half-life of the negative pressure is quite different from that of the sealed tobacco stack in the flat warehouse, the negative pressure of the sealed tent of the tobacco leaf storage high-rise warehouse changes little over time. At the same time, the air tightness test will affect the subsequent controlled atmosphere pest control cycle. Therefore, based on the air tightness test results and large-scale production applications, the lower limit of the test negative pressure in S1 is preferably -50Pa, and the corresponding upper limit of the test negative pressure is -25Pa. The negative pressure half-life in S2 is ≥97min. In this case, the airtightness of the sealed tent of the tobacco leaf storage high-rise warehouse meets the requirements for tobacco leaf storage, otherwise it does not meet the requirements.

[0014] In a specific embodiment, the above method for detecting the air tightness of a tobacco leaf storage high-bay warehouse further includes: Y1 Installing detection devices: installing detection devices on the existing tobacco leaf storage high-bay warehouse, the detection devices including pressure detectors and oxygen detectors; Y2 Determine the negative pressure limit of the sealed tent of the tobacco leaf storage high-rise warehouse: use an exhaust fan to draw air to form a negative pressure in the sealed tent of the tobacco leaf storage high-rise warehouse until the tent film is concave inward, and the film is under great tension but visually the film is not broken by internal suction, and the bottom edge of the tent is in contact with the ground without falling off or tearing. Stop the air extraction, and the corresponding measurement value of the pressure detector is the negative pressure limit that the sealed tent can withstand; In a specific embodiment, the method for detecting the air tightness of a tobacco leaf storage high-bay warehouse further includes: S3 airtightness verification: S31. Start the nitrogen generator to fill nitrogen from the air filling port of the sealed tent of the tobacco leaf storage high-bay warehouse, and gradually restore the air pressure in the stack until the pressure inside and outside the sealed tent is balanced; S32. Fill the sealed tent with nitrogen and reduce oxygen until the oxygen concentration in the tobacco leaf storage high-bay warehouse drops to <1.2%, and leave the tent still for 2 hours; S33. After the oxygen concentration is balanced, the data of the multi-point automatic oxygen concentration detector test is monitored, the oxygen concentration changes at different positions in the test stack are tested, and the manual oxygen concentration test is performed every 24h at the manual detection port for 7 days; S34. Analyzing the oxygen concentration detection data for 7 days, the increase in the oxygen concentration detection value is ≤0.02%, that is, the oxygen concentration detection value has not increased significantly, and the airtight performance of the sealed tent meets the requirements for tobacco leaf storage.

[0015] In Y1, the pressure detector is respectively installed at 6 detection points on different sides of the sealed tent of the tobacco storage elevated warehouse at 1.2 meters above the ground. The oxygen detector includes 16 oxygen detection probes and 1 detector controller. The oxygen detection probes are electrically connected to the detector controller. The oxygen detection probes are respectively installed at the top, middle and bottom of the four sides of the sealed tent of the tobacco storage elevated warehouse and dispersedly installed in the cigarette packs in the middle of the cigarette stack.

[0016] Beneficial effects of the method for detecting the air tightness of a tobacco leaf storage elevated warehouse of the present invention: Due to the structural characteristics of the metal shelves of the tobacco storage high-rise warehouse, it is impossible to determine the airtightness behind the sealed tent of the high-rise warehouse by traditional visual inspection. The applicant uses the pressure difference method to detect the airtightness of the tobacco storage high-rise warehouse. This method is simple to operate, and by detecting and analyzing the maintenance of the low-oxygen environment of the sealed tent of the high-rise warehouse for 7 days, it is verified that the pressure difference method is used to determine the negative pressure half-life and then determine the airtightness of the sealed tent of the high-rise warehouse. This method is scientific and feasible, and its detection efficiency is high.

[0017] This method for detecting the air tightness of tobacco leaf storage high-bay warehouses is more accurate than the traditional visual inspection method; compared with the existing detection methods in the air tightness requirements of flat warehouses, it further clarifies the pressure difference variation range suitable for the sealed curtains of tobacco leaf storage high-bay warehouses, clarifies the relationship between the pressure half-life and the air tightness judgment, and provides a practical technical solution for the air tightness detection of the sealed curtains of tobacco leaf storage high-bay warehouses, solving the problem that the traditional storage space air tightness detection method is not suitable for the air tightness detection of tobacco leaf storage high-bay warehouses. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 — is a distribution diagram of oxygen detection probe installation in a method for detecting air tightness of a tobacco leaf storage high-bay warehouse of the present invention; Figure 2 — is a distribution diagram of the installation of pressure detectors in a method for detecting the air tightness of a tobacco leaf storage high-bay warehouse of the present invention; Figure 3 — is a diagram showing the relationship between pressure decay and time in a method for detecting air tightness of a tobacco leaf storage high-bay warehouse of the present invention; Figure 4 — is a relationship diagram between the lower limit and upper limit of negative pressure and the half-life of negative pressure tested in a method for detecting the air tightness of a tobacco leaf storage high-bay warehouse in Examples 1 to 4. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] 1. Production of sealed tent for tobacco leaf storage high-bay warehouse: 1. Stack bottom treatment Use a broom, mop or rag to clean the preset cargo space, ensure that hard objects such as sand, wood chips, iron filings, nails, etc. are removed, lay isolation materials such as padding, cartons, colored strips or pallets in the preset cargo space, and keep the isolation materials clean and tidy.

[0021] 2 Sealed tent production a. Film splicing Accurately measure the actual size of the stack and splice the sealing film according to the measured size.

[0022] Bottom film length = stack length + 0.6m Bottom film width = stack width + 0.6m Top film length = stack length + 0.4m Top film width = stack width + 0.4m Width of film = height of smoke stack + 0.2m Length of surrounding film = (length of top film + width of top film) × 2 b. Before operation, check whether the belt and BRD-1000 ink wheel sealing machine are normal, and use waste film to perform heat sealing test.

[0023] c. Use the BRD-1000 ink wheel sealer to sew the two films together. During the operation, ensure that the position of the sealing film to be sewn does not change, so that the width of the suture line is not enough, resulting in suture failure. Use a portable chain heat sealer to make the cover film and the surrounding film into a cover film cover.

[0024] d. After the film is assembled and checked to confirm that it meets the standards, fold the film, indicate the film specifications and the stacking number to be used on the film, tie it with tape and place it in the designated location.

[0025] 3. Stacking a. Use empty cigarette boxes or other honeycomb cartons to stack cigarettes according to the size of the stack; b. Install a nitrogen filling port on the side of the stack close to the aisle or forklift passage; 4 The sealing of the tabernacle a. Use ordinary double-sided tape (4.5cm wide) to bond the film cover to the ground (to fix the film cover and increase the film cover's pulling resistance); b. Use 8cm wide special tape to cover the adhesive film cover film and the ground, and stick three-way tape.

[0026] 2. Install the detection device in the sealed tent of the tobacco storage high-bay warehouse Installing a detection device on the existing tobacco leaf storage high-bay warehouse, the detection device comprising a pressure detector and an oxygen detector; See attached Figure 1, oxygen concentration detector, the oxygen detector includes 16 oxygen detection probes and 1 detector controller, the oxygen detection probes are electrically connected to the detector controller, and the oxygen detection probes are respectively installed on the top, middle, and bottom of the four sides of the sealed tent of the tobacco storage elevated warehouse and the sealed tent of the tobacco storage elevated warehouse, and are dispersedly installed in the cigarette packs in the middle of the cigarette stack. The specific installation distribution positions of the oxygen detection probes are as follows Figure 1 As shown, preferably, the oxygen detection probe of the cigarette pack installed in the middle of the cigarette stack is about 15 meters away from the ground of the elevated warehouse; the detector controller is installed in the tent at a height of 1.2 meters above the ground to facilitate personnel to observe the screen.

[0027] The pressure detectors are installed at 6 detection points on different sides of the sealed tent of the tobacco storage high-bay warehouse 1.2 meters above the ground. The installation distribution positions of the pressure detectors are shown in the attached figure. Figure 2 As shown. There are 6 gas detection ports corresponding to the installation position of the pressure detector, which can be shared by the handheld oxygen detector and the handheld pressure detector.

[0028] After the overall installation is completed, a trial run of 2-4 hours is conducted to confirm that each detector is operating well and the controller screen readings are correct.

[0029] 3. The positive and negative pressure detection range of the sealed tent of the tobacco storage high-bay warehouse: At 3100m 3 and 5300m 3 Positive and negative pressure limit value tests were carried out in sealed tents of two high-bay tobacco storage warehouses of different specifications. Two parallel tests were set up for each group, including: 1. Positive pressure limit test Connect 6 pressure detectors to the gas detection port, turn on the fan to fill the tent with air, at this time, with 2 people in a group and one pressure detector, carefully observe the readings displayed by the pressure detectors, and observe the pressure-bearing state of the sealed tent film. When the air-bearing volume in the tent is greater than the tent volume, the five surface films of the tent bulge due to the positive pressure, and it is obvious that the film is under great tension (the tent will burst if the air is continued to be inflated), but the film has not burst visually, and the inflation is stopped when the adhesive part of the bottom edge of the tent that touches the ground does not fall off or tear. The positive pressure value measured by the pressure detector at this time is the positive pressure limit value that the tent can withstand.

[0030] 2 Negative pressure limit test Connect 6 pressure detectors to the gas detection port, connect the exhaust fan to the exhaust pipe port of the tent, turn on the exhaust fan to slowly exhaust air at a low air volume to form a negative pressure in the tent. At this time, 2 people are in a group with one pressure detector. Carefully observe the readings displayed on the pressure detector (and observe the pressure status of the tent film at the same time). When the tent film is concave inward, it is obvious that the film is under great tension (the tent will break if the air is continued to be pumped), but the film is not broken by visual observation, and the bottom edge of the tent is attached to the ground without falling off or tearing. Stop pumping. The negative pressure value measured by the pressure detector at this time is the limit value of the negative pressure that the tent can withstand.

[0031] The specific test results of the positive pressure limit and negative pressure limit of the sealed tent of the tobacco leaf storage high-bay warehouse are shown in Table 1.

[0032] Table 1 Positive / negative pressure limit values ​​of sealed tents for tobacco storage high-bay warehouses

[0033] The applicant found that when testing the positive pressure limit of the sealed tent in the tobacco leaf storage high-bay warehouse, the positive pressure Pa, air channels have been seen in the bottom part of the tent that is close to the ground, and there is a risk of the bottom of the tent being separated from the ground, and the positive pressure limit of the sealed tent of the tobacco storage high-rise warehouse is only 8Pa, which is difficult to meet the detection requirements of the positive pressure half-life in the pressure difference method; at the same time, when conducting the negative pressure limit test, if the micro-negative pressure in the storage stereoscopic warehouse tent is too large during the vacuum, such as the absolute value of the micro-negative pressure is greater than 60Pa, the applicant found that the sealed tent film of the tobacco storage stereoscopic warehouse is excessively concave and the force between the support frame / shelf body of the tobacco storage stereoscopic warehouse is too large, resulting in a large local stretching of the film, which poses a risk of scratching or rupture, and the negative pressure limit of the sealed tent of the tobacco storage stereoscopic warehouse is -62Pa; therefore, the applicant preliminarily determined to use the pressure difference method to test the negative pressure half-life for determining the air tightness of the sealed tent of the tobacco storage high-rise warehouse, and in view of the special shelf structure characteristics of the tobacco storage high-rise warehouse, according to the actual detected positive and negative pressure limit values ​​of the tent, the absolute value of the negative pressure of the tent air tightness detection is ≤- 60 Pa.

[0034] Example 1 The present embodiment provides a method for detecting air tightness of a tobacco leaf storage high-bay warehouse, including: S1 determines the negative pressure half-life of the sealed tent: start the exhaust fan to slowly exhaust air so that the sealed tent reaches the lower limit of the negative pressure test, and the detection value of the lower limit of the negative pressure test is ≥ the negative pressure limit value measured by S2. After the pressure in the sealed tent is balanced, start timing, and detect the pressure of the sealed tent every 2 minutes until the pressure of the sealed tent rises to the upper limit of the negative pressure test, and the absolute value of the upper limit of the negative pressure test = the absolute value of the lower limit of the negative pressure test * 1 / 2, stop timing, and get the negative pressure half-life t; S2 Air tightness determination: if the negative pressure half-life t measured by S1 is ≥ 60min, the air tightness of the sealed tent of the tobacco leaf storage high-rise warehouse meets the requirements for tobacco leaf storage, otherwise, it does not meet the requirements.

[0035] Among them, the maximum negative pressure that the sealed tent can withstand is -60Pa.

[0036] In this embodiment, the lower limit of the test negative pressure in S1 is -60Pa, the upper limit of the test negative pressure is -30Pa, and the corresponding negative pressure half-life is 70min.

[0037] Example 2 The present embodiment provides a method for detecting air tightness of a tobacco leaf storage high-bay warehouse, including: S1 determines the negative pressure half-life of the sealed tent: start the exhaust fan to slowly exhaust air so that the sealed tent reaches the lower limit of the negative pressure test, and the detection value of the lower limit of the negative pressure test is ≥ the negative pressure limit value measured by S2. After the pressure in the sealed tent is balanced, start timing, and detect the pressure of the sealed tent every 2 minutes until the pressure of the sealed tent rises to the upper limit of the negative pressure test, and the absolute value of the upper limit of the negative pressure test = the absolute value of the lower limit of the negative pressure test * 1 / 2, stop timing, and get the negative pressure half-life t; S2 Air tightness determination: if the negative pressure half-life t measured by S1 is ≥ 60min, the air tightness of the sealed tent of the tobacco leaf storage high-rise warehouse meets the requirements for tobacco leaf storage, otherwise, it does not meet the requirements.

[0038] Among them, the maximum negative pressure that the sealed tent can withstand is -60Pa.

[0039] In this embodiment, the lower limit of the test negative pressure in S1 is -50Pa, the upper limit of the test negative pressure is -25Pa, and the corresponding negative pressure half-life is 97min.

[0040] Example 3 Compared with Example 1, the method for detecting the air tightness of a tobacco leaf storage high-bay warehouse in this embodiment has the following differences: The lower limit of the test negative pressure in S1 is -40Pa, the upper limit of the test negative pressure is -20Pa, and the corresponding negative pressure half-life is 125min.

[0041] Example 4 Compared with Example 1, the method for detecting the air tightness of a tobacco leaf storage high-bay warehouse in this embodiment has the following differences: The lower limit of the test negative pressure in S1 is -30Pa, the upper limit of the test negative pressure is -15Pa, and the corresponding negative pressure half-life is 132min.

[0042] In the method for detecting the air tightness of a tobacco leaf storage high-bay warehouse in Examples 1 to 4, the change of the negative pressure half-life of the air tightness of the tobacco leaf storage high-bay warehouse obtained by the test is as follows: Figure 4 After the sealed tent of the tobacco leaf storage high-rise warehouse is sealed, as the absolute value of the lower limit of the negative pressure test decreases, the negative pressure half-life time gradually increases, and as the absolute value of the lower limit of the negative pressure test decreases, the duration of the negative pressure half-life first increases quickly and then slowly, and gradually tends to be flat, especially in Examples 3 and 4, the difference in the negative pressure half-life of -40Pa~-20Pa and -30Pa~-15Pa is significantly smaller than the difference in the negative pressure half-life of -50Pa~-25Pa and -40Pa~-20Pa.

[0043] Based on the structural characteristics of tobacco leaf storage high-rise warehouses, combined with the fact that the minimum negative pressure limit value in the negative pressure limit test of the sealed tent of tobacco leaf storage high-rise warehouses is -50Pa, and when the lower limit of the negative pressure test is increased again, the corresponding negative pressure half-life time is significantly prolonged, and considering the large-scale production application and actual production operation of tobacco leaf storage high-rise warehouses, the applicant believes that it is preferable to use the pressure difference method under the conditions of a test negative pressure lower limit of -50Pa and a test negative pressure upper limit of -25Pa to test the half-life of the sealed tent of tobacco leaf storage high-rise warehouses, and then determine the quality of the airtightness of the sealed tent of the tobacco leaf storage high-rise warehouse and whether it meets the storage requirements.

[0044] Example 5 After the tobacco leaf storage high-bay warehouse is sealed with a bottom-film-free sealed tent, the longer its pressure half-life is, the better the airtightness of the sealed tent is. Figure 3 It can be seen that the relationship between the tent pressure decay and time, the pressure values ​​at each detection point of the bottom-film sealed tent in the tobacco storage high-rise warehouse increased from -60 Pa to -15 Pa, showing a trend of first fast and then slow, and the trend was consistent. The whole process took more than 3 hours.

[0045] The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse further comprises: After the pressure value at each detection point of the bottom-film sealed tent of the tobacco leaf storage high-bay warehouse increased from -60 Pa to -15 Pa, the S3 airtightness verification began: S31. Start the nitrogen generator to fill nitrogen from the air filling port of the sealed tent of the tobacco leaf storage high-bay warehouse, and gradually restore the air pressure in the stack until the pressure inside and outside the sealed tent is balanced; S32. Fill the sealed tent with nitrogen and reduce oxygen until the oxygen concentration in the tobacco leaf storage high-bay warehouse drops to <1.2%, and leave the tent still for 2 hours; S33. After the oxygen concentration is balanced, the data of the multi-point automatic oxygen concentration detector test is monitored, the oxygen concentration change values ​​at different positions in the test stack are tested, and the manual oxygen concentration test is performed every 24h at the manual detection port for 7 days, and the multi-point oxygen detection probe and the handheld oxygen detector are used to detect the corresponding tobacco storage high-bay warehouse oxygen concentration as shown in Table 2 and Table 3 respectively; Table 2 Test data of multi-point automatic oxygen concentration detector

[0046] Table 3 7-day oxygen concentration detected by handheld oxygen detector at multiple points

[0047] S34. Analyzing the oxygen concentration detection data of 7 days, the increase in the oxygen concentration detection value is ≤0.02%, that is, the oxygen concentration detection value has not increased significantly. The airtightness of the sealed tent meets the requirements for tobacco storage. It also proves that the negative pressure half-life detection used in Examples 1 to 4 can be used to determine the quality of the airtightness of the tobacco storage high-rise warehouse.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

Claims

1. A method for detecting the air tightness of a tobacco leaf storage high-bay warehouse, characterized in that: The pressure difference method is used to detect the negative pressure half-life in the sealed tent of the tobacco leaf storage high-rise warehouse, and the test negative pressure lower limit ≥ the negative pressure limit value of the sealed tent, the absolute value of the test negative pressure upper limit = the absolute value of the test negative pressure lower limit * 1 / 2, and the negative pressure half-life is ≥ 60min.

2. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 1, characterized in that: The lower limit of the test negative pressure ranges from -60Pa to -30Pa.

3. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 1, characterized in that: The method comprises: S1 determines the negative pressure half-life of the sealed tent: start the exhaust fan to slowly exhaust air so that the sealed tent reaches the lower limit of the negative pressure test, and the detection value of the lower limit of the negative pressure test is ≥ the negative pressure limit value measured by S2. After the pressure in the sealed tent is balanced, start timing, and detect the pressure of the sealed tent every 1 to 3 minutes until the pressure of the sealed tent rises to the upper limit of the negative pressure test, and the absolute value of the upper limit of the negative pressure test = the absolute value of the lower limit of the negative pressure test * 1 / 2, stop timing, and get the negative pressure half-life t; S2 Air tightness determination: if the negative pressure half-life t measured by S1 is ≥ 60min, the air tightness of the sealed tent of the tobacco leaf storage high-rise warehouse meets the requirements for tobacco leaf storage, otherwise, it does not meet the requirements.

4. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 3, characterized in that: The pressure detection range corresponding to the negative pressure half-life in S1 is -60Pa ~ -15Pa.

5. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 3, characterized in that: The lower limit of the negative pressure tested in S1 is -50Pa, and the corresponding upper limit of the negative pressure tested is -25Pa. The half-life of the negative pressure in S2 is ≥97min. The airtightness of the sealed tent of the tobacco leaf storage high-bay warehouse meets the requirements for tobacco leaf storage. Otherwise, it does not meet the requirements.

6. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 3, characterized in that: The maximum negative pressure that a sealed tent can withstand is -60Pa.

7. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 3, characterized in that: The method further comprises: Y1 Installing detection devices: installing detection devices on the existing tobacco leaf storage high-bay warehouse, the detection devices including pressure detectors and oxygen detectors; Y2 determines the negative pressure limit of the sealed tent of the tobacco storage high-rise warehouse.

8. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 3 or 7, characterized in that: The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse further comprises: S3 airtightness verification: S31. Start the nitrogen generator to fill nitrogen from the air filling port of the sealed tent of the tobacco leaf storage high-bay warehouse, and gradually restore the air pressure in the stack until the pressure inside and outside the sealed tent is balanced; S32. Fill the sealed tent with nitrogen and reduce oxygen until the oxygen concentration in the tobacco leaf storage high-bay warehouse drops to <1.2%, and leave the tent still for 2 hours; S33. After the oxygen concentration is balanced, the data of the multi-point automatic oxygen concentration detector test is monitored, the oxygen concentration changes at different positions in the test stack are tested, and the manual oxygen concentration test is performed every 24h at the manual detection port for 7 days; S34. Analyze the oxygen concentration detection data for 7 days. The increase in the oxygen concentration detection value is ≤0.02%. The airtight performance of the sealed tent meets the requirements for tobacco leaf storage.

9. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 7, characterized in that: In Y1, the pressure detector is respectively installed at 6 detection points on different sides of the sealed tent of the tobacco storage elevated warehouse at 1.2 meters above the ground. The oxygen detector includes 16 oxygen detection probes and 1 detector controller. The oxygen detection probes are electrically connected to the detector controller. The oxygen detection probes are respectively installed at the top, middle and bottom of the four sides of the sealed tent of the tobacco storage elevated warehouse and dispersedly installed in the cigarette packs in the middle of the cigarette stack.

10. The method for detecting the air tightness of a tobacco leaf storage high-bay warehouse according to claim 7, characterized in that: The specific operation of the Y2 method for determining the negative pressure limit value of the sealed tent of the tobacco leaf storage elevated warehouse is as follows: use an exhaust fan to draw air to form a negative pressure in the sealed tent of the tobacco leaf storage elevated warehouse until the tent film is concave inward, and the film is under great tension but the film is visually not broken by internal suction, and the bottom edge of the tent is in contact with the ground without any detachment or tearing, then stop drawing air, and the corresponding measurement value of the pressure detector is the negative pressure limit value that the sealed tent can withstand.

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