A straw sterilization device, its control method and application

Abstract

This application relates to the field of environmental protection technology, and in particular to a straw sterilization equipment, its control method, and its application. The equipment includes M fumigation devices, N pressure-reducing devices, M heat exchange devices, and a steam device. The M fumigation devices are connected in parallel, the N pressure-reducing devices are connected in parallel, the M heat exchange devices are connected in series, the steam device is connected in series with the fumigation devices, and the M fumigation devices are used in series with the N pressure-reducing devices, and the N pressure-reducing devices are used in series with the M heat exchange devices. M ≥ 3, N ≥ 6, and 2M - 1 ≤ N ≤ 2M, where M and N are integers. With this configuration, compared to existing technologies, the average number of pressure-reducing devices and heat exchange devices required per fumigation device is reduced by at least two. This shortens the pressure reduction and sterilization time, improves the straw sterilization efficiency, reduces cost and energy consumption, lowers energy efficiency, minimizes nutrient loss from the straw, and improves the quality of the straw product.

Description

Technical Field

[0001] This invention relates to the field of environmental protection, particularly to organic solid waste treatment and resource utilization technologies and key technologies for environmentally friendly manufacturing, specifically to a straw sterilization device and its control method and application. Background Technology

[0002] Northeast my country has abundant rice cultivation and production, and its latitude and longitude are basically the same as Japan's. The rice straw has good color, thick fiber, and less pesticide use. In addition, the climate is moderate in humidity and suitable for storage and processing, which makes it a favorite of Japanese rice straw merchants.

[0003] The raw rice straw must be sourced from areas within 50 kilometers of the origin that have not experienced any infectious disease outbreaks for at least three years, and the straw must be free of foreign matter other than soil and packaging materials. The raw rice straw must be stored in a disinfected area, and insects must be prevented from entering it. The raw rice straw undergoes a series of processes including impurity removal, drying, bundling, sterilization, and packaging. As described in patent application CN107307188A, impurity removal refers to removing impurities from the raw rice straw using specialized equipment. Drying refers to drying the impurity-removed raw rice straw at a temperature between 70-260℃ using specialized drying equipment. Bundling refers to bundling the dried straw using a baler to form bundles. Sterilization involves placing bundles of straw into a sealed fumigation canister, ensuring a minimum spacing of 3 cm between the bundles. After closing the canister, steam is introduced to fumigate the straw bundles. The bundles are then removed from the canister. During fumigation, all parts of the steam-heated straw bundles must reach 80°C and be maintained for 10 minutes, with a further 4 minutes at or above 86°C. Alternatively, the straw bundles can be individually heated to above 86°C. After confirming the absence of live insects, the bundles are packaged in sterilized boxes, completing the packing process.

[0004] Currently, all Wagyu beef straw feed manufacturers in China depressurize fumigation tanks during the sterilization process to meet sterilization requirements. Specifically, each fumigation tank is equipped with four 22kW vacuum pumps connected in series, and a shell-and-tube heat exchanger is connected externally. The multiple fumigation tanks operate independently. If six fumigation tanks are required, 24 22kW vacuum pumps are needed, each independent and without mutual interference. This sterilization process consumes a lot of energy, has high energy efficiency, and is costly. If each fumigation tank is connected to only one 88kW vacuum pump, the cost of one 88kW vacuum pump is higher than four 22kW vacuum pumps. This results in a longer depressurization time during sterilization, lower straw sterilization efficiency, low straw production efficiency, and high costs. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies, such as high energy consumption, low energy efficiency, and high cost. It proposes a straw sterilization device with short sterilization time, short decompression time, high efficiency, low energy consumption, and low cost, as well as its control method and application.

[0006] A straw sterilization device includes M fumigation devices, N pressure reducing devices, M heat exchange devices, and a steam device. The steam device generates steam and delivers it to the fumigation devices for sterilizing the straw. The pressure reducing devices reduce the pressure of the fumigation devices, and the heat exchange devices cool the pressure reducing devices. The M fumigation devices are connected in parallel, the N pressure reducing devices are connected in parallel, the M heat exchange devices are connected in series, the steam device is connected in series with the M fumigation devices, the M fumigation devices are connected in series with the N pressure reducing devices, and the N pressure reducing devices are connected in series with the M heat exchange devices. M ≥ 3, N ≥ 6, and 2M - 1 ≤ N ≤ 2M, where M and N are integers.

[0007] Furthermore, the fumigation device has a first door on one side and a second door on the other side; the bottom of the fumigation device has a first air inlet and a second air inlet connected to a steam device, and a first drain outlet and a second drain outlet for draining water from the fumigation device, with the first air inlet and the first drain outlet located close to the first door, and the second air inlet and the second drain outlet located close to the second door; the top of the fumigation device has at least one exhaust outlet and at least one pressure reducing outlet connected to a pressure reducing device, at least one third temperature measuring port for detecting the temperature inside the fumigation device, and at least one safety valve; the side of the fumigation device has a first temperature measuring port, a second temperature measuring port, a first pressure measuring port, a second pressure measuring port, and a third pressure measuring port; the first temperature measuring port is located at the upper end of the side of the fumigation device near the first door. The first temperature measuring port is located between the first door and the first drain outlet; the second temperature measuring port is located between the first drain outlet and the first air inlet, and is located in the middle of the side of the fumigation device, with the height of the first temperature measuring port being higher than that of the second temperature measuring port; the first pressure measuring port is located in the middle of the side of the fumigation device near the first door, and is located between the first door and the first drain outlet; the second pressure measuring port is located in the middle of the side of the fumigation device near the first door, and is located between the first air inlet and the pressure reducing port; the third pressure measuring port is located in the middle of the side of the fumigation device near the second door, and is located between the second drain outlet and the second door; the first, second, and third temperature measuring ports are used to detect the temperature at this location within the fumigation device; the first, second, and third pressure measuring ports are used to detect the pressure at this location within the fumigation device.

[0008] Furthermore, the fumigation device is also equipped with a first spare port, a second spare port, a third spare port, and a fourth spare port; the first spare port is located at the bottom of the fumigation device and between the first drain port and the first air inlet; the second spare port is located at the bottom of the fumigation device and between the second drain port and the second air inlet; the third spare port is located at the top of the fumigation device and between the pressure reducing port and the third temperature measuring port; the fourth spare port is located at the top of the fumigation device and between the first door and the pressure reducing port.

[0009] Furthermore, the second temperature measuring port is located between the first spare port and the first air inlet, and between the first pressure measuring port and the second pressure measuring port; the first pressure measuring port, the first temperature measuring port, the second pressure measuring port, and the third pressure measuring port are at the same height on the side of the fumigation device.

[0010] Furthermore, the internal volume of each fumigation device is at least 130 cubic meters, and the power of each pressure reducing device is at least 22 kW.

[0011] Furthermore, the internal volume of each fumigation device is at least 130 cubic meters, and each heat exchange device is a shell-and-tube heat exchange device of 1200mm × 3000mm.

[0012] Furthermore, the quantitative relationships among the fumigation devices, pressure reducing devices, and heat exchange devices are as follows: 3 fumigation devices are connected in parallel; 6 pressure reducing devices are connected in parallel; 3 heat exchange devices are connected in series; the steam device is connected in series with all 3 fumigation devices; the entire 3 fumigation devices are connected in series with all 6 pressure reducing devices, and the entire 6 pressure reducing devices are connected in series with all 3 heat exchange devices; or, 4 fumigation devices are connected in parallel; 8 pressure reducing devices are connected in parallel; 4 heat exchange devices are connected in series; the steam device is connected in series with the fumigation devices; the steam device is connected in series with all 4 fumigation devices; the entire 4 fumigation devices are connected in series with all 8 pressure reducing devices, and the entire 8 pressure reducing devices are connected in series with all 4 heat exchange devices. The following configurations can be used in series: 1) Five fumigation units connected in parallel; 10 pressure-reducing units connected in parallel; 5 heat exchangers connected in series; a steam unit connected in series with the fumigation units; a steam unit connected in series with all five fumigation units; or 5 fumigation units connected in series with all ten pressure-reducing units, and the 10 pressure-reducing units connected in series with all five heat exchangers. Alternatively, six fumigation units connected in parallel; 12 pressure-reducing units connected in parallel; 6 heat exchangers connected in series; a steam unit connected in series with the fumigation units; a steam unit connected in series with all six fumigation units; or 6 fumigation units connected in series with all twelve pressure-reducing units, and the 12 pressure-reducing units connected in series with all six heat exchangers. Alternatively, 7 fumigation units are connected in parallel, 13 pressure-reducing units are connected in parallel, 7 heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all 7 fumigation units, and all 7 fumigation units are connected in series with all 13 pressure-reducing units, with all 13 pressure-reducing units connected in series with all 7 heat exchange units; or, 8 fumigation units are connected in parallel, 15 pressure-reducing units are connected in parallel, 8 heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all 8 fumigation units, and all 8 fumigation units are connected in series with all 15 pressure-reducing units, with all 15 pressure-reducing units connected in series with all 8 heat exchange units; or... Nine fumigation units are connected in parallel, 17 pressure reducing units are connected in parallel, nine heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all nine fumigation units, and all nine fumigation units are connected in series with all 17 pressure reducing units, and all 17 pressure reducing units are connected in series with all nine heat exchange units; or, ten fumigation units are connected in parallel, 19 pressure reducing units are connected in parallel, ten heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all ten fumigation units, and all ten fumigation units are connected in series with all 19 pressure reducing units, and all 19 pressure reducing units are connected in series with all ten heat exchange units.

[0013] Furthermore, the fumigation device is a fumigation tank, the pressure reducing device is a vacuum pump, the heat exchange device is a shell-and-tube heat exchanger group, and the steam device is connected in series with M parallel fumigation tanks, N parallel vacuum pumps, and M series shell-and-tube heat exchanger groups.

[0014] A control method for a straw sterilization device, applied to any of the straw sterilization devices described above, the straw sterilization control method comprising: S1: stacking bundled straw at a spacing of at least 3 cm into a fumigation device, sealing the fumigation device, using all pressure reducing devices to evacuate one fumigation device until the pressure inside the fumigation device reaches a pressure threshold, then using a steam device to fill the fumigation device with steam, and starting the heat exchange device; S2: after the pressure inside the fumigation device in S1 reaches the pressure threshold, using all pressure reducing devices to evacuate another fumigation device until the pressure inside that fumigation device reaches the pressure threshold, then using a steam device to fill the fumigation device with steam; S3: repeating S2 until the pressure inside all fumigation devices has reached the pressure threshold, and the steam device has filled all fumigation devices with steam.

[0015] A straw sterilization device according to any one of the above claims, or an application of the above control method, wherein the straw sterilization device or the control method is used for straw sterilization.

[0016] The embodiments of the present invention have the following beneficial effects:

[0017] M fumigation devices are connected in parallel, N pressure-reducing devices are connected in parallel, M heat exchangers are connected in series, a steam device is connected in series with the M fumigation devices, and the M fumigation devices are connected in series with the N pressure-reducing devices, and the N pressure-reducing devices are connected in series with the M heat exchangers. M ≥ 3, N ≥ 6, and 2M - 1 ≤ N ≤ 2M, where M and N are integers. This setup, compared to existing technologies where each fumigation device requires four pressure-reducing devices connected in series, and these four devices are connected in series with four heat exchangers, with multiple fumigation tanks operating independently, and where 24 22kW vacuum pumps are required for six fumigation tanks to operate independently without mutual interference, reduces the average number of pressure-reducing devices per fumigation device by at least two and the number of heat exchangers by at least one. This equipment shortens the pressure-reducing time, reduces the heating time of the straw, improves the straw sterilization efficiency, has low cost, low energy consumption, and low energy efficiency. By shortening the heating time and decompression time of the straw, less nutrients are lost from the sterilized straw, thus improving the quality of straw products. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A simplified structural diagram of a straw sterilization device (6 fumigation devices, 12 pressure reducing devices, and 6 heat exchange devices) provided by the present invention;

[0020] Figure 2 for Figure 1 A magnified view of a section at point A;

[0021] Figure 3 for Figure 1 A magnified view of section B;

[0022] Figure 4 for Figure 1 A magnified view of section C;

[0023] Figure 5 This is a three-dimensional schematic diagram of the fumigation device provided by the present invention;

[0024] Figure 6 for Figure 5 Enlarged view of a section at point D;

[0025] Figure 7 for Figure 5 A magnified view of a section at point E. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] It should be noted that the terms “vertical,” “horizontal,” “left,” “right,” and similar expressions used in this article are for illustrative purposes only.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the template description is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] like Figures 1 to 7 As shown, a straw sterilization device includes M fumigation devices 2, N pressure reducing devices 4, M heat exchange devices 3, and a steam device 1. The steam device 1 generates steam and delivers it to the fumigation devices 2 for sterilizing the straw. The pressure reducing devices 4 reduce the pressure of the fumigation devices 2, and the heat exchange devices 3 cool the pressure reducing devices 4. The M fumigation devices 2 are connected in parallel, the N pressure reducing devices 4 are connected in parallel, and the M heat exchange devices 3 are connected in series. The steam device 1 is connected in series with the fumigation devices 2, and the M fumigation devices 2 and N pressure reducing devices 4 are connected in series. The N pressure reducing devices 4 and M heat exchange devices 3 are also connected in series. M ≥ 3, N ≥ 6, and 2M - 1 ≤ N ≤ 2M, where M and N are integers. Alternatively, 10 ≥ M ≥ 3, 19 ≥ N ≥ 6, and 2M - 1 ≤ N ≤ 2M, where M and N are integers. Alternatively, 6 ≥ M ≥ 3, 12 ≥ N ≥ 6, and N = 2M, where M and N are integers. Alternatively, 10 ≥ M ≥ 7, 19 ≥ N ≥ 13, and N = 2M - 1, where M and N are integers. In this embodiment, the 6 fumigation devices 2 are connected in parallel, the 12 pressure reducing devices 4 are connected in parallel, and the 6 heat exchange devices 3 are connected in series. The steam device 1 and the entire assembly of the 6 parallel fumigation devices 2, the entire assembly of the 6 series heat exchange devices 3, and the entire assembly of the 12 series pressure reducing devices 4 are connected in series sequentially.

[0032] like Figures 5 to 7 As shown, the fumigation device 2 has a first door 201 on one side and a second door 202 on the other side. The first door 201 and the second door 202 are used to feed bundled, unsterilized straw into the fumigation device 2, and can also be used to remove sterilized straw from the fumigation device 2. During the sterilization process, the fumigation device 2 can be kept under reduced pressure. The bottom of the fumigation device 2 is provided with a first air inlet 211 and a second air inlet 212 connected to the steam device 1, and a first drain outlet 221 and a second drain outlet 222 for draining water from the fumigation device 2. The first air inlet 211 and the first drain outlet 221 are located near the first door 201, and the second air inlet 212 and the second drain outlet 222 are located near the second door 202. The top of the fumigation device 2 is provided with at least one exhaust outlet 23 and at least one pressure reducing outlet 24 connected to the pressure reducing device 4, at least one third temperature measuring port 253 for detecting the temperature inside the fumigation device 2, and at least one safety valve 26. The sides of the fumigation device 2 are provided with a first temperature measuring port 251, a second temperature measuring port 252, a first pressure measuring port 271, a second pressure measuring port 272, and a third pressure measuring port 273. The first temperature measuring port 251 is located at the upper end of the side of the fumigation device 2 near the first door 201, and is located between the first door 201 and the first drain outlet 221. The second temperature measuring port 252 is located between the first drain port 221 and the first air inlet 211, and is situated in the middle of the side of the fumigation device 2, with the height of the first temperature measuring port 251 being higher than that of the second temperature measuring port 252; the first pressure measuring port 271 is located in the middle of the side of the fumigation device 2 near the first door 201, and is situated between the first door 201 and the first drain port 221; the second pressure measuring port 272 is located in the middle of the side of the fumigation device 2 near the first door 201. The first air inlet 211 and the pressure reducing port 24 are located at the middle of the side of the fumigation device 2 near the second door 202, and between the second drain outlet 222 and the second door 202. The first temperature measuring port 251, the second temperature measuring port 252 and the third temperature measuring port 253 are used to detect the temperature at this location in the fumigation device 2. The first pressure measuring port 271, the second pressure measuring port 272 and the third pressure measuring port 273 are used to detect the pressure at this location in the fumigation device 2.

[0033] like Figures 1 to 7As shown, in this embodiment, six fumigation devices 2 are connected in parallel via vacuum pipelines, twelve pressure-reducing devices 4 are connected in parallel, and six heat exchange devices 3 are connected in series. The steam device 1, the entire assembly of the six parallel fumigation devices 2, one vacuum buffer device 5, the entire assembly of the six series-connected heat exchange devices 3, and the entire assembly of the twelve series-connected pressure-reducing devices 4 are sequentially connected in series. The steam device 1 is equipped with a steam inlet pipe 101 and a steam outlet pipe 102. The steam inlet pipe 101 is connected to the first air inlet 211 and the second air inlet 212 of the six fumigation devices 2, and the steam outlet pipe 102 is connected to the exhaust port 23, allowing steam to enter from both ends of the fumigation device 2 and exit from the middle, which is beneficial for sterilizing the straw. The first drain port 221 and the second drain port 222 are used to drain the condensate inside the fumigation device 2 to prevent bacterial growth inside the fumigation device, which would affect the sterilization effect of the straw. Temperature measuring devices are installed at the first temperature measuring port 251, the second temperature measuring port 252, and the third temperature measuring port 253 to detect the temperature inside the straw at that port. These devices can be inserted deep into the fumigation device to determine the internal straw temperature and whether the straw has reached the sterilization temperature, ensuring effective sterilization. Pressure measuring devices are installed at the first pressure measuring port 271, the second pressure measuring port 272, and the third pressure measuring port 273 to detect the pressure at that port. These devices can be inserted deep into the fumigation device to determine the internal straw pressure and whether the straw has reached the sterilization pressure, preventing overpressure and ensuring effective sterilization. A vacuum pipeline 41 is connected to the pressure reduction port 24 of the fumigation device 2. Six heat exchangers 3 connected in series are installed outside the vacuum pipeline 41 to cool the gas inside to below 60°C. The vacuum pipeline 41 is also connected to a vacuum buffer device 5. The vacuum buffer device 5 is connected in parallel with 12 pressure reducing devices 4 via pipelines. In this embodiment, the heat exchange device 3 is equipped with parallel water inlet pipes 31 and parallel water outlet pipes 32, which are connected to the water tank 6. The exhaust port 23 is used to restore the pressure reduction state inside the fumigation device 2 to the local atmospheric pressure state where the equipment is located. The fumigation device 2 is also provided with a first spare port 281, a second spare port 282, a third spare port 283, and a fourth spare port 284; the first spare port 281 is located at the bottom of the fumigation device 2 and is located between the first drain port 221 and the first air inlet 211; the second spare port 282 is located at the bottom of the fumigation device 2 and is located between the second drain port 222 and the second air inlet 212; the third spare port 283 is located at the top of the fumigation device 2 and is located between the pressure reducing port 24 and the third temperature measuring port 273; the fourth spare port 283 is located at the top of the fumigation device 2 and is located between the first door 101 and the pressure reducing port 24.The second temperature measuring port 252 is located between the first spare port 281 and the first air inlet 211, and between the first pressure measuring port 271 and the second pressure measuring port 272; the first pressure measuring port 271, the first temperature measuring port, the second pressure measuring port 272, and the third pressure measuring port 273 are at the same height on the side of the fumigation device 2. This arrangement facilitates the measurement of the internal temperature of the straw, ensuring that the temperature is controlled within the set range during the straw sterilization process. In this embodiment, 16 first temperature measuring ports 251 at the same height are provided to detect the internal temperature of the straw near the measuring port at that location. If the sterilization temperature exceeds the predicted temperature, the straw will turn black, resulting in a decrease in straw quality and loss of nutrients such as protein in the sterilized straw. Low temperatures will cause the straw to fail to achieve the sterilization effect, leading to bacterial growth and rendering it unusable. The spare port can be used in emergencies when temperature and pressure need to be adjusted. The safety valve is used to control the pressure.

[0034] Each fumigation unit has an internal volume of at least 130 cubic meters, and each pressure-reducing device has a power of at least 22 kW. The ratio of the internal volume of each fumigation unit to the power of each pressure-reducing device is 130 cubic meters : 22 kW.

[0035] Each fumigation unit has an internal volume of at least 130 cubic meters, and each heat exchanger is a shell-and-tube heat exchanger with a diameter of 1200 mm × 3000 mm. The ratio of the internal volume of each fumigation unit, the power of each pressure reducing unit, and the heat exchanger to each shell-and-tube heat exchanger is 130 cubic meters : 22 kW : 1200 mm × 3000 mm.

[0036] The number and connection relationship of the fumigation device, pressure reducing device, and heat exchange device can be any one of the following (1) to (8):

[0037] (1) The three fumigation devices are connected in parallel, the six pressure reducing devices are connected in parallel, the three heat exchange devices are connected in series, the steam device is connected in series with the three fumigation devices, the three fumigation devices are connected in series with the six pressure reducing devices, and the six pressure reducing devices are connected in series with the three heat exchange devices.

[0038] (2) The four fumigation devices are connected in parallel with each other, the eight pressure reducing devices are connected in parallel with each other, the four heat exchange devices are connected in series with each other, the steam device is connected in series with the fumigation device, the steam device is connected in series with the four fumigation devices as a whole, the four fumigation devices as a whole are connected in series with the eight pressure reducing devices as a whole, and the eight pressure reducing devices as a whole are connected in series with the four heat exchange devices as a whole.

[0039] (3) Five fumigation devices are connected in parallel with each other, ten pressure reducing devices are connected in parallel with each other, five heat exchange devices are connected in series with each other, steam device is connected in series with fumigation device, steam device is connected in series with five fumigation devices as a whole, five fumigation devices as a whole are connected in series with ten pressure reducing devices as a whole, and ten pressure reducing devices as a whole are connected in series with five heat exchange devices as a whole.

[0040] (4) The six fumigation devices are connected in parallel with each other, the twelve pressure reducing devices are connected in parallel with each other, the six heat exchange devices are connected in series with each other, the steam device is connected in series with the fumigation device, the steam device is connected in series with the six fumigation devices as a whole, the six fumigation devices as a whole are connected in series with the twelve pressure reducing devices as a whole, and the twelve pressure reducing devices as a whole are connected in series with the six heat exchange devices as a whole.

[0041] (5) Seven fumigation devices are connected in parallel with each other, 13 pressure reducing devices are connected in parallel with each other, seven heat exchange devices are connected in series with each other, steam device is connected in series with fumigation device, steam device is connected in series with seven fumigation devices as a whole, seven fumigation devices as a whole are connected in series with 13 pressure reducing devices as a whole, and 13 pressure reducing devices as a whole are connected in series with seven heat exchange devices as a whole.

[0042] (6) Eight fumigation devices are connected in parallel with each other, 15 pressure reducing devices are connected in parallel with each other, eight heat exchange devices are connected in series with each other, steam device is connected in series with fumigation device, steam device is connected in series with eight fumigation devices as a whole, eight fumigation devices as a whole are connected in series with 15 pressure reducing devices as a whole, and 15 pressure reducing devices as a whole are connected in series with eight heat exchange devices as a whole.

[0043] (7) Nine fumigation devices are connected in parallel with each other, 17 pressure reducing devices are connected in parallel with each other, nine heat exchange devices are connected in series with each other, steam device is connected in series with fumigation device, steam device is connected in series with nine fumigation devices as a whole, nine fumigation devices as a whole are connected in series with 17 pressure reducing devices as a whole, and 17 pressure reducing devices as a whole are connected in series with nine heat exchange devices as a whole.

[0044] (8) Ten fumigation devices are connected in parallel with each other, 19 pressure reducing devices are connected in parallel with each other, 10 heat exchange devices are connected in series with each other, steam device is connected in series with fumigation device, steam device is connected in series with 10 fumigation devices as a whole, 10 fumigation devices as a whole are connected in series with 19 pressure reducing devices as a whole, and 19 pressure reducing devices as a whole are connected in series with 10 heat exchange devices as a whole.

[0045] The specific method for sterilizing rice straw is as follows: Stack the rice straw at least 3 cm intervals inside the fumigation device. After closing the fumigation device, simultaneously activate all pressure-reducing devices to create a vacuum in one of the fumigation devices until the pressure inside reaches 0.094 MPa. Then, inject steam into the fumigation device to fumigate the bundled rice straw, heating it. After each 10-minute steam injection, monitor the heated temperature of the rice straw inside the fumigation device using the first temperature measuring port 251, the second temperature measuring port 252, and the third temperature measuring port 253. If the temperature does not reach 86°C, stop injecting steam into the fumigation device. During the intervals between steam injections, create a vacuum inside the fumigation device. If cooling water is available, drain it before re-injecting steam. Continue this process until the temperature of all parts of the rice straw reaches above 86°C and below 115°C. The straw closest to the first air inlet 211 and the second air inlet 212 has reached 115°C, while other straw bales have not yet reached 86°C. Steam injection is then stopped. The fumigation device is evacuated again using all pressure-reducing devices, and steam is then injected into the tank to ensure that the temperature of all parts of the straw bales reaches above 86°C and below 115°C as quickly as possible. Steam injection is stopped after the straw temperature remains above 86°C and below 115°C for at least 4 minutes. The total steam injection time for the entire sterilization process is 20 minutes. During steam heating, all heat exchange devices are activated to prevent excessively high steam temperatures from damaging the pressure-reducing devices.

[0046] The straw was sterilized according to the above-mentioned straw sterilization method, and the straw products were fed to Wagyu cattle. Simultaneously, the straw was sterilized using a method where each fumigation device was connected in series with four pressure-reducing devices and four heat exchangers, and the straw products were fed to Wagyu cattle. The straw sterilization equipment using the number and connection relationship of fumigation devices, pressure-reducing devices, and heat exchangers in (1) to (8) was used to sterilize the straw. Experiments showed that, compared to each fumigation device connected in series with four pressure-reducing devices and four heat exchangers, the pressure-reducing time of the sterilization process in the straw sterilization equipment in (1) to (4) was shortened from 20 minutes to 5 minutes, improving the straw sterilization efficiency, reducing cost, and minimizing energy consumption. Because the pressure-reducing time was shortened, less nutrients were lost from the sterilized straw. Using the same weight of sterilized straw to feed Wagyu cattle resulted in a 10%-15% increase in weight. The sterilization time of the straw sterilization equipment in (5) to (8) is shortened from 20 minutes to 4 minutes, which improves the sterilization efficiency of straw, reduces cost, and minimizes energy consumption. Because the reduced sterilization time, less nutrients are lost from the sterilized straw. Wagyu cattle fed with the same weight of sterilized straw for one month showed a 10%-15% increase in weight gain.

[0047] The fumigation device is a fumigation tank 2, the pressure reducing device 4 is a vacuum pump, and the heat exchange device 3 is a shell and tube heat exchanger assembly.

[0048] The straw sterilization control method of the straw sterilization equipment described in any one of the above claims includes:

[0049] S1: Stack the bundled straw at a spacing of at least 3 cm into the fumigation device, seal the fumigation device, use all pressure reducing devices to evacuate the fumigation device until the pressure inside the fumigation device reaches the pressure threshold, then use the steam device to fill the fumigation device with steam and start the heat exchange device.

[0050] S2: After the pressure in the fumigation device described in S1 reaches the pressure threshold, use all pressure reducing devices to evacuate the other fumigation device until the pressure in that fumigation device reaches the pressure threshold, and then use a steam device to fill the fumigation device with steam.

[0051] S3: Repeat S2 until the pressure in all fumigation devices has reached the pressure threshold and the steam device has filled all fumigation devices with steam.

[0052] In this embodiment, M fumigation devices 2 are connected in parallel, N pressure reducing devices 4 are connected in parallel, M heat exchange devices 3 are connected in series, steam device 1 is connected in series with fumigation devices 2, M fumigation devices 2 are connected in series with N pressure reducing devices 4, and the N pressure reducing devices 4 as a whole are connected in series with M heat exchange devices 3 as a whole. M ≥ 3, N ≥ 6, and 2M - 1 ≤ N ≤ 2M, where M and N are integers. In this embodiment, 6 fumigation devices 2 are connected in parallel, 12 pressure reducing devices 4 are connected in parallel, 6 heat exchange devices 3 are connected in series, and steam device 1 is connected in series with the 6 parallel fumigation devices 2 as a whole, the 6 series heat exchange devices 3 as a whole, and the 12 series pressure reducing devices 4 as a whole.

[0053] During the sterilization process, when depressurizing the three fumigation devices, S1: Six depressurization devices are used to depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, three heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, six depressurization devices are used to evacuate the other fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all three fumigation devices reaches 0.094 MPa, and steam has been introduced into all three devices.

[0054] During the sterilization process, when depressurizing the four fumigation devices, S1: Eight depressurization devices are used to depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, four heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, eight depressurization devices are used to evacuate the other fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all four fumigation devices reaches 0.094 MPa, and steam has been introduced into all four devices.

[0055] During the sterilization process, when depressurizing the five fumigation devices, S1: Ten depressurization devices depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, five heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, ten depressurization devices are used to evacuate another fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all five fumigation devices reaches 0.094 MPa, and steam has been introduced into all five devices.

[0056] During the sterilization process, when depressurizing the six fumigation devices, S1: 12 depressurization devices depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, the six heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, the 12 depressurization devices are used to evacuate the other fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator. S3: S2 is repeated until the pressure inside all six fumigation devices has reached 0.094 MPa, and steam has been introduced into all six devices.

[0057] During the sterilization process, when depressurizing the seven fumigation devices, S1: Thirteen depressurization devices depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, seven heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, the thirteen depressurization devices are used to evacuate another fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all seven fumigation devices has reached 0.094 MPa, and steam has been introduced into all seven devices.

[0058] During the sterilization process, when depressurizing the 8 fumigation devices, S1: 15 depressurization devices depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, the 8 heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, the 15 depressurization devices are used to evacuate another fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all 8 fumigation devices has reached 0.094 MPa, and steam has been introduced into all fumigation devices.

[0059] During the sterilization process, when depressurizing the 9 fumigation devices, S1: 17 depressurization devices depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, 9 heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, the 17 depressurization devices are used to evacuate another fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all 9 fumigation devices has reached 0.094 MPa, and steam has been introduced into all fumigation devices.

[0060] During the sterilization process, when depressurizing the 10 fumigation devices, S1: 19 depressurization devices depressurize one of the fumigation devices until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into the fumigation device using a steam generator to fumigate the straw. Simultaneously, 10 heat exchangers are activated. S2: After the pressure inside the fumigation device reaches 0.094 MPa as described in S1, the 19 depressurization devices are used to evacuate another fumigation device until the pressure inside that device reaches 0.094 MPa. Steam is then introduced into that device using a steam generator. S3: S2 is repeated until the pressure inside all 10 fumigation devices has reached 0.094 MPa, and steam has been introduced into all 10 devices.

[0061] An application of the straw sterilization equipment described in any of the above claims, or the straw sterilization control method described above, wherein the straw sterilization equipment or the straw sterilization control method is used for straw sterilization.

[0062] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0064] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A straw sterilization device, comprising M fumigation devices, N pressure-reducing devices, M heat exchange devices, and a steam device, wherein the steam device generates steam and delivers the steam to the fumigation devices, the fumigation devices are used to sterilize the straw, the pressure-reducing devices are used to reduce the pressure of the fumigation devices, and the heat exchange devices are used to cool the pressure-reducing devices; characterized in that... M fumigation devices are connected in parallel, N pressure reducing devices are connected in parallel, M heat exchange devices are connected in series, a steam device is connected in series with M fumigation devices, M fumigation devices are connected in series with N pressure reducing devices, and N pressure reducing devices are connected in series with M heat exchange devices. M ≥ 3, N ≥ 6, and 2M - 1 ≤ N ≤ 2M. M and N are both integers. The fumigation device has a first door on one side and a second door on the other side. The bottom of the fumigation device has a first air inlet and a second air inlet connected to a steam device, and a first drain outlet and a second drain outlet for discharging water from the fumigation device. The first air inlet and the first drain outlet are located near the first door, and the second air inlet and the second drain outlet are located near the second door. The top of the fumigation device has at least one exhaust outlet and at least one pressure reducing outlet connected to a pressure reducing device, at least one third temperature measuring port for detecting the temperature inside the fumigation device, and at least one safety valve. The side of the fumigation device has a first temperature measuring port, a second temperature measuring port, a first pressure measuring port, a second pressure measuring port, and a third pressure measuring port. The first temperature measuring port is located at the upper end of the side of the fumigation device near the first door. The first temperature measuring port is located between the first door and the first drain outlet; the second temperature measuring port is located between the first drain outlet and the first air inlet, and is located in the middle of the side of the fumigation device, with the height of the first temperature measuring port being higher than that of the second temperature measuring port; the first pressure measuring port is located in the middle of the side of the fumigation device near the first door, and is located between the first door and the first drain outlet; the second pressure measuring port is located in the middle of the side of the fumigation device near the first door, and is located between the first air inlet and the pressure reducing port; the third pressure measuring port is located in the middle of the side of the fumigation device near the second door, and is located between the second drain outlet and the second door; the first, second, and third temperature measuring ports are used to detect the temperature at that location within the fumigation device; the first, second, and third pressure measuring ports are used to detect the pressure at that location within the fumigation device.

2. The straw sterilization equipment according to claim 1, characterized in that, The fumigation device is also equipped with a first spare port, a second spare port, a third spare port, and a fourth spare port; the first spare port is located at the bottom of the fumigation device and between the first drain port and the first air inlet; the second spare port is located at the bottom of the fumigation device and between the second drain port and the second air inlet; the third spare port is located at the top of the fumigation device and between the pressure reducing port and the third temperature measuring port; the fourth spare port is located at the top of the fumigation device and between the first door and the pressure reducing port.

3. The straw sterilization equipment according to claim 2, characterized in that, The second temperature measuring port is located between the first spare port and the first air inlet, and between the first pressure measuring port and the second pressure measuring port; the first pressure measuring port, the first temperature measuring port, the second pressure measuring port, and the third pressure measuring port are at the same height on the side of the fumigation device.

4. The straw sterilization equipment according to claim 1, characterized in that, Each fumigation unit has an internal volume of at least 130 cubic meters, and each pressure reducing unit has a power of at least 22 kW.

5. The straw sterilization equipment according to claim 1, characterized in that, Each fumigation unit has an internal volume of at least 130 cubic meters, and each heat exchanger is a shell-and-tube heat exchanger with a diameter of 1200 mm × 3000 mm.

6. The straw sterilization equipment according to claim 1, characterized in that, The quantitative relationships among the fumigation unit, pressure reducing unit, and heat exchange unit are as follows: 3 fumigation units are connected in parallel; 6 pressure reducing units are connected in parallel; 3 heat exchange units are connected in series; the steam unit is connected in series with the 3 fumigation units; the 3 fumigation units are connected in series with the 6 pressure reducing units; and the 6 pressure reducing units are connected in series with the 3 heat exchange units. Alternatively, Four fumigation units are connected in parallel; eight pressure-reducing units are connected in parallel; four heat exchange units are connected in series; a steam unit is connected in series with the fumigation units; a steam unit is connected in series with all four fumigation units; all four fumigation units are connected in series with all eight pressure-reducing units; and all eight pressure-reducing units are connected in series with all four heat exchange units; or... Five fumigation units are connected in parallel; ten pressure-reducing units are connected in parallel; five heat exchange units are connected in series; a steam unit is connected in series with the fumigation units; a steam unit is connected in series with all five fumigation units; the five fumigation units are connected in series with all ten pressure-reducing units; and the ten pressure-reducing units are connected in series with all five heat exchange units; or... Six fumigation units are connected in parallel, twelve pressure-reducing units are connected in parallel, six heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all six fumigation units, all six fumigation units are connected in series with all twelve pressure-reducing units, and all twelve pressure-reducing units are connected in series with all six heat exchange units; or... Seven fumigation units are connected in parallel, thirteen pressure-reducing units are connected in parallel, seven heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all seven fumigation units, all seven fumigation units are connected in series with all thirteen pressure-reducing units, and all thirteen pressure-reducing units are connected in series with all seven heat exchange units; or... Eight fumigation units are connected in parallel, fifteen pressure-reducing units are connected in parallel, eight heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all eight fumigation units, all eight fumigation units are connected in series with all fifteen pressure-reducing units, and all fifteen pressure-reducing units are connected in series with all eight heat exchange units; or... Nine fumigation units are connected in parallel, 17 pressure-reducing units are connected in parallel, nine heat exchange units are connected in series, a steam unit is connected in series with the fumigation units, a steam unit is connected in series with all nine fumigation units, and all nine fumigation units are connected in series with all 17 pressure-reducing units, and all 17 pressure-reducing units are connected in series with all nine heat exchange units; or... Ten fumigation devices are connected in parallel, 19 pressure reducing devices are connected in parallel, 10 heat exchange devices are connected in series, a steam device is connected in series with the fumigation devices, a steam device is connected in series with the 10 fumigation devices as a whole, the 10 fumigation devices as a whole are connected in series with the 19 pressure reducing devices as a whole, and the 19 pressure reducing devices as a whole are connected in series with the 10 heat exchange devices as a whole.

7. The straw sterilization equipment according to claim 1, characterized in that, The fumigation device is a fumigation tank, the pressure reducing device is a vacuum pump, the heat exchange device is a shell-and-tube heat exchanger assembly, and the steam device is connected in series with M parallel fumigation tanks, N parallel vacuum pumps, and M series shell-and-tube heat exchanger assemblies.

8. A control method for a straw sterilization device, applied to the straw sterilization device according to any one of claims 1-7, characterized in that, The control method includes: S1: Stack the bundled straw at a spacing of at least 3 cm into the fumigation device, seal the fumigation device, use all pressure reducing devices to evacuate the fumigation device until the pressure inside the fumigation device reaches the pressure threshold, then use the steam device to fill the fumigation device with steam and start the heat exchange device. S2: After the pressure in the fumigation device described in S1 reaches the pressure threshold, use all pressure reducing devices to evacuate the other fumigation device until the pressure in that fumigation device reaches the pressure threshold, and then use a steam device to fill the fumigation device with steam. S3: Repeat S2 until the pressure in all fumigation devices has reached the pressure threshold and the steam device has filled all fumigation devices with steam.

9. A straw sterilization device according to any one of claims 1-7, characterized in that, The straw sterilization equipment is used for sterilizing straw.

10. An application of a control method using the straw sterilization equipment of claim 8, characterized in that, The control method is used for sterilizing rice straw.

Images