Pipeline system for nitrogen charging in grain storage

Abstract

The utility model discloses a pipeline system for grain storage nitrogen charging. The pipeline system comprises an upper nitrogen charging opening formed in a granary and a plurality of ventilation units arranged at the bottom of the granary. The upper inflation inlet is connected with a nitrogen supply pipeline, and a first valve is arranged on the nitrogen supply pipeline; the ventilation unit comprises a first exhaust fan and a ground cage; with the first valve as a boundary, the pipe section, located in front of the first valve, of the oxygen supply pipeline is defined as a first pipe section, and the pipe section, located behind the first valve, of the oxygen supply pipeline is defined as a second pipe section; a newly added nitrogen supply pipe is arranged between the ventilation unit and the first pipe section, so that the nitrogen supply pipe supplies nitrogen to the ventilation unit; and a newly added exhaust pipe is arranged on the second pipe section. The pipeline system can flexibly switch nitrogen charging modes, the nitrogen charging efficiency is remarkably improved, and the improvement cost is low.

Description

A pipeline system for nitrogen filling in grain storage Technical Field

[0001] This utility model relates to the field of grain storage technology, and in particular to a pipeline system for nitrogen filling in grain storage. Background Technology

[0002] Controlled atmosphere storage (CAS) is a green, environmentally friendly, safe, and effective technology for controlling stored grain pests. It involves filling a well-sealed warehouse with high-purity nitrogen gas, significantly reducing the oxygen content in the air and thus controlling stored grain pests (refer to existing technology 1). According to the "Technical Regulations for Nitrogen-Controlled Atmosphere Storage" (refer to existing technology 2), the current method of using pressure swing adsorption (PSA) nitrogen generators and airbags to seal the grain surface in tall, flat warehouses for nitrogen-controlled atmosphere storage has achieved significant results in controlling grain pests and maintaining grain quality.

[0003] According to the current nitrogen filling and exhaust process of the technical specification, the nitrogen filling pipeline system in the grain warehouse is shown in Figures 1 and 2. The grain warehouse is equipped with an upper nitrogen filling port (1) and multiple ventilation units (2) set at the bottom of the grain warehouse. The upper nitrogen filling port (1) is connected to the nitrogen supply pipeline (3). Nitrogen gas is filled into the grain warehouse through the upper nitrogen filling port (1). The ventilation unit (2) includes a first exhaust fan (21) and a ground cage (22). Driven by the first exhaust fan (21), the gas in the grain warehouse is exhausted from the ground cage (22). However, the inventor found that this "upper filling and exhaust" method has problems such as excessively long filling time and uneven and insufficient nitrogen filling. In practice, it was found that the nitrogen filling dead zone and incomplete pest control in the long-term upper filling and exhaust nitrogen filling process may be the main reasons for the increase in grain loss rate in recent years.

[0004] Existing technology 1: Zhang Lailin, Jin Wen, Fu Pengcheng, et al. Development and application of controlled atmosphere storage technology for grain in my country [J]. Grain and Feed Industry, 2011, 09: 20-23;

[0005] Existing technology 2: LS / T 1225—2022 Technical Specification for Nitrogen Controlled Atmosphere Grain Storage. Summary of the Invention

[0006] In view of this, this utility model proposes a pipeline system for nitrogen filling in grain storage, aiming to achieve a more efficient, uniform and sufficient nitrogen filling effect by optimizing the pipeline layout, reducing nitrogen filling dead zones, improving the thoroughness of insect control, and thus reducing grain loss rate.

[0007] The solution provided by this utility model includes:

[0008] A pipeline system for nitrogen filling in grain storage includes:

[0009] Nitrogen filling vents are installed at the top inside the grain silo, and multiple ventilation units are installed at the bottom of the grain silo.

[0010] The upper nitrogen filling port is connected to a nitrogen supply pipe, and the nitrogen supply pipe is equipped with a first valve.

[0011] The ventilation unit includes a first exhaust fan and a floor cage;

[0012] Using the first valve as a boundary, the section of the nitrogen supply pipeline before the first valve is defined as the first section, and the section of the nitrogen supply pipeline after the first valve is defined as the second section.

[0013] A new nitrogen supply pipe is provided between the ventilation unit and the first pipe section to enable the nitrogen supply pipe to supply nitrogen to the ventilation unit;

[0014] A new exhaust pipe is installed on the second pipe section.

[0015] As a further optional solution, a second valve is provided on the newly added nitrogen supply pipe;

[0016] The newly added exhaust pipe is equipped with a third valve.

[0017] As a further optional solution, the newly added exhaust pipe is connected to a second exhaust fan.

[0018] As a further optional solution, the newly added nitrogen supply pipe includes a main pipe, branch pipes, and connecting pipes;

[0019] Each branch pipe corresponds to a ventilation unit, the main pipe is connected to the ventilation unit through the branch pipe, and the main pipe is connected to the first section of the nitrogen supply pipeline through the connecting pipe.

[0020] The second valve is installed on the connecting pipe.

[0021] Compared with existing technologies, the nitrogen-filling pipeline system for grain storage proposed in this application has at least the following advantages:

[0022] 1. Flexible switching of nitrogen filling modes: Existing technologies are limited to a single nitrogen filling mode of "top filling and bottom discharging," while this application, through optimization of the pipeline structure, successfully achieves an organic combination (not simultaneously) of "bottom filling and top discharging" and "top filling and bottom discharging" modes. Operators can freely switch nitrogen filling modes according to different grain warehouse environments, grain types, and actual needs, greatly expanding the application scope of nitrogen filling modes.

[0023] 2. Significantly Improved Nitrogen Filling Efficiency: In the "bottom filling, top discharging" mode, nitrogen enters from the bottom of the grain silo, quickly filling the lower space of the grain pile and gradually diffusing upwards. In the "top filling, bottom discharging" mode, nitrogen enters from the top nitrogen filling port and permeates downwards into the grain pile. The two modes can be flexibly switched according to actual conditions, forming an efficient airflow circulation that greatly accelerates the diffusion rate of nitrogen within the grain silo, significantly shortens the nitrogen filling time, and improves nitrogen filling efficiency. Furthermore, it avoids the problem of insufficient nitrogen concentration in localized areas, improving the uniformity of nitrogen filling.

[0024] 3. Low modification cost: The pipeline system structure of this application is simple and can be easily modified from the existing "top-filling, bottom-draining" pipeline system. By adding new nitrogen supply pipes and new exhaust pipes, and by reasonably adjusting the pipeline layout, there is no need for large-scale modification of the grain silo, which greatly reduces the modification cost and improves the practicality and economy of the solution. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the piping system in a grain silo (tall, flat-roofed warehouse) in the prior art;

[0026] Figure 2 is a schematic diagram of the piping system in Figure 1;

[0027] Figure 3 is a schematic diagram of a nitrogen-filling pipeline system for grain storage according to an embodiment of the present invention.

[0028] Figure 4 is a schematic diagram of gas flow in a nitrogen-filling pipeline system for grain storage according to an embodiment of the present invention in the "top filling and bottom discharging" nitrogen filling mode;

[0029] Figure 5 is a schematic diagram of gas flow in a nitrogen-filling pipeline system for grain storage according to an embodiment of the present invention in the "bottom filling and top discharging" nitrogen filling mode;

[0030] Figure 6 shows the nitrogen concentration data in the chamber 30 days before and after the completion of the "top filling and bottom venting" nitrogen filling in the experimental group.

[0031] Figure 7 shows the nitrogen concentration data in the chamber 30 days before and after the completion of the nitrogen filling process of the experimental group, which involved "top filling and bottom venting" and "bottom filling and top venting".

[0032] Figure 8 shows the nitrogen concentration data in the chamber 30 days before and after the completion of the "bottom filling and top venting" nitrogen filling in the experimental group.

[0033] In the diagram: 1. Upper nitrogen filling port;

[0034] 2. Ventilation unit; 21. First exhaust fan; 22. Floor cage;

[0035] 3. Nitrogen supply pipeline; 31. First pipeline section; 32. Second pipeline section;

[0036] 4. First valve;

[0037] 5. New nitrogen supply pipe; 51. Main pipe; 52. Branch pipe; 53. Connecting pipe;

[0038] 6. Added exhaust pipe;

[0039] 7. Second valve;

[0040] 8. Third valve. Detailed Implementation

[0041] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0042] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0043] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," 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 utility model according to the specific circumstances.

[0044] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] Referring to Figures 3-5, an embodiment of this utility model shows a pipeline system for nitrogen filling in grain storage, including an upper nitrogen filling port 1 installed in the grain silo and multiple ventilation units 2 installed at the bottom of the grain silo. The upper nitrogen filling port is connected to a nitrogen supply pipe 3, and the nitrogen supply pipe 3 is provided with a first valve 4. The ventilation unit 2 includes a first exhaust fan 21 and a ground cage 22.

[0046] Using the first valve 4 as a boundary, the section of the nitrogen supply pipeline before the first valve 4 is defined as the first pipe section 31, and the section of the nitrogen supply pipeline after the first valve 4 is defined as the second pipe section 32; a new nitrogen supply pipe 5 is provided between the ventilation unit 2 and the first pipe section 31 to enable the nitrogen supply pipeline 3 to supply nitrogen to the ventilation unit 2; a new exhaust pipe 6 is provided on the second pipe section 32.

[0047] As shown in Figure 3, the newly added nitrogen supply pipe 5 is equipped with a second valve 7, and the newly added exhaust pipe 6 is equipped with a third valve 8.

[0048] Specifically, by adding the new nitrogen supply pipe 5 and the new exhaust pipe 6, the ventilation unit 2 is filled with nitrogen from below, and the upper nitrogen filling port is exhausted from above.

[0049] Specifically, when "top filling and bottom exhaust" is required: as shown in Figures 3 and 4, the first valve 4 is opened, the second valve 7 and the third valve 8 are closed, the nitrogen gas supplied by the nitrogen supply pipeline 3 is filled into the grain silo through the upper nitrogen filling port 1, the first exhaust fan 21 is turned on, and the gas in the grain silo is discharged through the ground cage 22.

[0050] When "bottom filling and top exhaust" is required: as shown in Figures 3 and 5, the first valve 4 is closed, and the second valve 7 and the third valve 8 are opened. The nitrogen gas introduced by the nitrogen supply pipeline enters the newly added nitrogen supply pipe 5. At this time, the first exhaust fan 21 is closed, and the nitrogen gas in the newly added nitrogen supply pipe 5 is filled into the grain silo through the ground cage 22. The gas in the grain silo is discharged from the upper nitrogen filling port 1, and the gas enters the second pipe end of the nitrogen supply pipeline 3 from the upper nitrogen filling port 1 and is discharged through the newly added exhaust pipe 6.

[0051] In some embodiments, to improve the exhaust effect in the "bottom charging and top discharging" nitrogen charging mode, the newly added exhaust pipe 6 is connected to a second exhaust fan (not shown).

[0052] In some embodiments, as shown in FIG3, the newly added nitrogen supply pipe 5 includes a main pipe 51, branch pipes 52, and connecting pipes 53; the branch pipes 52 correspond one-to-one with the ventilation units 2, the main pipe 51 is connected to the ventilation units 2 through the branch pipes 52, and the main pipe 51 is connected to the first section 31 of the nitrogen supply pipe through the connecting pipes 53; the second valve 7 is disposed on the connecting pipe 53. Thus, only the second valve 7 needs to be controlled to control the switching of nitrogen filling / exhausting functions of multiple ventilation units 2.

[0053] In this embodiment, the ventilation unit 2 is provided with four units.

[0054] In one specific embodiment, referring to Figure 1, a tall, flat warehouse is used as the test warehouse. The warehouse is 60m long and 24m wide, with a designed grain stacking line of 6m and a rated capacity of 6000t. Four exhaust vents are located at the bottom of the east or west wall of the warehouse, spaced 13m apart. Each exhaust vent is equipped with a first-row fan and connected to three east-west oriented ground cages 22. The ground cages 22 have a diameter of 0.6m and are spaced 3.5m apart. A nitrogen filling port 1 is located 5m above the ground on the wall.

[0055] The test chamber was modified by connecting the first section 31 of the original nitrogen supply pipeline 3 to a north-south PPR pipe (as the main pipe 51). The PPR pipe was then connected to four exhaust ports at the bottom of the east or west wall of the chamber via branch pipes 52. In addition, a flexible hose (i.e., a new exhaust pipe 6) was connected to the first section 31 of the original nitrogen supply pipeline 3 and then connected to a second exhaust fan. Second valves 7 and third valves 8 were installed at the corresponding pipeline locations to control the gas direction and flow rate.

[0056] This embodiment sets up three test groups: "top charging bottom discharge", "top charging bottom discharge + bottom charging top discharge", and "bottom charging top discharge". The test results are shown in Table 1 below:

[0057] Table 1. Cost Analysis of Controlled Atmosphere in Different Experimental Groups

[0058]

[0059] Experiments show that, under the premise that the airtightness of the warehouse reaches level one (more than 20 minutes, -300 to -150 Pa), the nitrogen filling time of the above-mentioned modified pipeline is shortened from 41 hours to 32 hours (24 hours for top filling and bottom filling and 8 hours for bottom filling and top filling in this embodiment), and the cost per ton of grain is reduced by 0.13 yuan / ton / time of nitrogen filling.

[0060] Furthermore, please refer to Figures 6-8. Although the single bottom-filling and top-draining nitrogen filling mode increases the nitrogen filling time to 54 hours, it effectively reduces nitrogen dead zones and evens out the nitrogen concentration in the grain pile. Even after 30 days of nitrogen filling, the gas concentration in the grain pile remains high and uniform, effectively killing pests in the dead zones of the original nitrogen filling process.

[0061] In summary, this application provides a pipeline system for nitrogen filling in grain storage, and the beneficial effects of this pipeline system are as follows:

[0062] 1. Flexible switching of nitrogen filling modes: Existing technologies are limited to a single nitrogen filling mode of "top filling and bottom discharging," while this application, through optimization of the pipeline structure, successfully achieves an organic combination (not simultaneously) of "bottom filling and top discharging" and "top filling and bottom discharging" modes. Operators can freely switch nitrogen filling modes according to different grain warehouse environments, grain types, and actual needs, greatly expanding the application scope of nitrogen filling modes.

[0063] 2. Significantly Improved Nitrogen Filling Efficiency: In the "bottom filling, top discharging" mode, nitrogen enters from the bottom of the grain silo, quickly filling the lower space of the grain pile and gradually diffusing upwards. In the "top filling, bottom discharging" mode, nitrogen enters from the upper nitrogen filling port 1 and permeates downwards into the grain pile. The two modes can be flexibly switched according to actual conditions, forming an efficient airflow circulation that greatly accelerates the diffusion rate of nitrogen within the grain silo, significantly shortens the nitrogen filling time, and improves nitrogen filling efficiency. Furthermore, it avoids the problem of insufficient nitrogen concentration in localized areas, improving the uniformity of nitrogen filling.

[0064] 3. Low modification cost: The pipeline system structure of this application is simple and can be easily modified from the existing "top-filling and bottom-draining" pipeline system. By adding a new nitrogen supply pipe 5 and a new exhaust pipe 6, and by reasonably adjusting the pipeline layout, there is no need for large-scale modification of the grain silo, which greatly reduces the modification cost and improves the practicality and economy of the solution.

[0065] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0066] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A pipeline system for nitrogen filling in grain storage, comprising: The system comprises an upper nitrogen inlet located inside a grain silo and multiple ventilation units located at the bottom of the silo; the upper nitrogen inlet is connected to a nitrogen supply pipe, and the nitrogen supply pipe is equipped with a first valve; the ventilation unit includes a first exhaust fan and a ground cage; characterized in that: taking the first valve as a boundary, the section of the nitrogen supply pipe before the first valve is defined as the first pipe section, and the section of the nitrogen supply pipe after the first valve is defined as the second pipe section; an additional nitrogen supply pipe is provided between the ventilation unit and the first pipe section to enable the nitrogen supply pipe to supply nitrogen to the ventilation unit; and an additional exhaust pipe is provided on the second pipe section.

2. The pipeline system for nitrogen filling in grain storage according to claim 1, characterized in that: The newly added nitrogen supply pipe is equipped with a second valve; the newly added exhaust pipe is equipped with a third valve.

3. The pipeline system for nitrogen filling in grain storage according to claim 2, characterized in that: The newly added exhaust pipe is connected to a second exhaust fan.

4. The pipeline system for nitrogen filling in grain storage according to claim 3, characterized in that: The newly added nitrogen supply pipe includes a main pipe, branch pipes, and connecting pipes; each branch pipe corresponds to a ventilation unit, the main pipe is connected to the ventilation unit through the branch pipes, and the main pipe is connected to the first section of the nitrogen supply pipeline through the connecting pipes; the second valve is installed on the connecting pipe.

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