Oil tank modified bulk grain warehouse grain storage system and warehouse in and out method thereof

Abstract

The application discloses an oil tank modified bulk grain storage system, which comprises a plurality of tank bodies arranged in an oil tank area, an inlet system, an outlet system and a ventilation system; the feed inlet of the tank body is used as the grain inlet, and a plurality of horizontal reinforcing ribs and a plurality of vertical columns are uniformly arranged on the inner side; the inlet system: a grain lifting tower is arranged on the side of the oil tank area, a transverse and longitudinal trestle is arranged on the top of the grain inlet, the trestle is communicated with the grain lifting tower, a multi-point unloading machine is arranged on the trestle, and the discharge port of the multi-point unloading machine is communicated with the grain inlet; the outlet system: a cushion layer is laid on the bottom of the tank body, a plurality of outlet ports are uniformly arranged on the top center line of the cushion layer, an outlet channel is arranged below the outlet port, and a scraper is arranged in the outlet channel; and the ventilation system: a plurality of ventilation holes one are arranged on the top of the tank body, and a ventilation groove is arranged on the cushion layer. The oil tank area is modified into a bulk grain storage system, the original layout of the oil tank area is reasonably utilized, the overall modification process is simple, the modification cost is low, and after the modification, the automatic inlet and outlet of the bulk grain can be realized.

Description

Technical Field

[0001] This invention relates to the field of grain storage engineering technology, and in particular to a grain storage system converted from an oil tank and its loading and unloading method. Background Technology

[0002] With the deepening of the national food security strategy and the continuous development of the grain industry economy, the total demand and quality requirements for grain storage and logistics infrastructure are increasing simultaneously. Against this backdrop, efficiently utilizing existing assets and revitalizing existing industrial facilities to quickly establish safe and reliable new storage capabilities at relatively low cost has become a crucial issue for the industry. Functional renovation and upgrading of existing storage tanks that meet the requirements offers significant advantages over new projects, including shorter construction cycles, lower investment costs, and higher land use efficiency. This is an effective path to promote the intensive and sustainable development of the storage industry.

[0003] Currently, many grain depots in China are designed with large oil tank systems. With adjustments to grain reserves, many of these large oil tanks are now idle. Converting them into bulk grain silos could not only reduce asset idleness losses but also significantly enhance grain storage capacity, thus creating a need for functional conversion. However, oil storage and grain storage differ fundamentally in material characteristics, load distribution, process requirements, and environmental control, making direct conversion a series of serious challenges. Furthermore, systematic research both domestically and internationally on directly converting large vertical storage tanks into shallow, circular bulk grain silos lacks mature, reliable, and standardized technical frameworks for guidance. Regarding structural safety, the lateral pressure characteristics and bulk density of grain differ significantly from those of liquids; therefore, tank structure, foundation bearing capacity, and seismic resistance must all be considered. In terms of the process system, grain loading and unloading require a completely different mechanized and automated conveying and cleaning system than fluid handling. The above conversion needs to simplify the conversion process as much as possible, minimizing the impact on the original tank structure and layout, controlling conversion costs, and ensuring the stability of bulk grain storage while achieving automated loading and unloading. Summary of the Invention

[0004] In view of this, the purpose of this invention is to address the shortcomings of the prior art by providing an oil tank to bulk grain storage system and its loading and unloading method, which transforms the oil tank area into a bulk grain storage system, makes reasonable use of the original oil tank area layout, has a simple overall transformation process, low transformation cost, and enables automated loading and unloading of bulk grain after transformation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A grain storage system converted from oil tanks to bulk grain warehouses includes multiple tanks arranged in an oil tank area, an inlet system, an outlet system, and a ventilation system. The feed inlet of the tank serves as the grain inlet, and multiple horizontal reinforcing ribs and multiple vertical columns are evenly arranged on the inner side; Grain loading system: Grain lifting towers are arranged on the side of the oil tank area. Horizontal and vertical trestle bridges are set at the top of the grain inlet. The trestle bridges are connected to the grain lifting towers. Multi-point unloading machines are arranged on the trestle bridges. The discharge port of the multi-point unloading machines is connected to the grain inlet, forming a bulk grain loading system. Outlet system: A pad layer is laid at the bottom of the tank, and multiple outlets are evenly arranged on the center line of the top of the pad layer. An outlet channel is set below the outlets, and a scraper conveyor is set in the outlet channel. A multi-point feeding conveyor is set in the middle of the tank area. The outlet of the scraper conveyor is connected to the multi-point feeding conveyor to form an outlet system for bulk grain. Ventilation system: Multiple ventilation holes are provided on the top of the tank, and ventilation trenches are provided on the bedding layer.

[0006] Furthermore, the vertical column has a hollow structure with two ventilation holes evenly arranged on the upper inner side, and the upper part of the vertical column is connected to the external fan.

[0007] Furthermore, the outlet of the warehouse passage is an equipment outlet, and a grain-blocking gate is installed above the equipment outlet.

[0008] Furthermore, a reinforcing structure is provided around the equipment opening and the grain-blocking gate.

[0009] Furthermore, the foundation consists of three layers: a concrete foundation, a soil foundation, and a reinforced concrete foundation, from bottom to top. The walls of the exit passage are made of reinforced concrete structural slabs, and the reinforcing bars in the reinforced concrete foundation are anchored into the walls of the exit passage.

[0010] Furthermore, a ventilation trough is provided on the cushion layer, which is connected to an external fan.

[0011] Furthermore, the outlet located at the center of the warehouse bottom is the main outlet, and the other outlets are secondary outlets. A steel grid plate is installed at the top of the outlet, and a spiral cleaning machine is installed on the steel grid plate above the main outlet.

[0012] Furthermore, annular flat steel bars are evenly distributed on the outside of the tank body, and insulation strips are laid between the annular flat steel bars. The insulation strips are fixed with ring reinforcement on the outside and then fixed with diagonal reinforcement in a V-shape. The outermost layer is covered with color steel plate.

[0013] A method for loading and unloading grain in a tank-to-bulk-grain storage system includes the following steps: 1) Loading method: Bulk grain is lifted by the grain lifting tower to the multi-point unloading machine on the trestle, and enters the tank through the discharge port and grain inlet of the multi-point unloading machine; 2) Outbound method: Open the outlet, the bulk grain enters the scraper conveyor, and after passing through the scraper conveyor, it enters the multi-point feeding conveyor and is transported to the next process.

[0014] The beneficial effects of this invention are: 1. This invention discloses a bulk grain storage system for converting oil tanks into bulk grain storage facilities. The overall conversion strategy is as follows: the main structure and foundation of the original oil tanks remain unchanged, while a bulk grain inlet system, an outlet system, and a ventilation system are added. An external insulation structure is also added. The existing layout is utilized rationally, avoiding unnecessary demolition and reconstruction, and minimizing external pressure on the oil tanks to save on conversion costs. The converted storage system enables automatic inlet and outlet, and the overall conversion process is simple and cost-effective. The converted system meets the requirements for bulk grain storage, achieving efficient resource integration.

[0015] For the grain inlet system, a grain lifting tower is arranged on the side of the oil tank area, and horizontal and vertical trestle bridges are set on the top of the grain inlet. Multi-point unloading machines are arranged on the trestle bridges, and the discharge ports of the multi-point unloading machines are connected to the grain inlet to form the grain inlet system. In order to reduce the pressure on the oil tanks, a support frame is set between the two oil tanks on the trestle bridge, and the entire trestle bridge is supported by multiple support frames.

[0016] The unloading system elevates the bottom of the oil tanks with a three-layer bedding layer to increase stability and strength. An unloading outlet and passageway are provided in the middle, with a scraper conveyor installed within the passageway. A multi-point feeding conveyor is longitudinally arranged in the center of the tank area, and the scraper conveyor outlet at the bottom of each tank is connected to the multi-point feeding conveyor. Combined with the spiral cleaning machine at the bottom of the tank, automated unloading operations can be achieved.

[0017] In addition, symmetrical ventilation troughs are arranged on the upper part of the cushion layer on both sides of the warehouse passage to achieve ventilation at the bottom of the warehouse; natural ventilation openings and fans are arranged on the top of the warehouse, forming a ventilation system for the bulk grain warehouse together with the ventilation troughs at the bottom of the warehouse. In addition, the upper part of the vertical columns can be set as a hollow structure, with two ventilation holes arranged on the inside, which can be connected to the external fan to achieve lateral ventilation of the upper part of the bulk grain.

[0018] 5. The tank body reinforcement mainly adopts an internal reinforcement system, which forms a network reinforcement structure of vertical columns and horizontal reinforcing ribs on the inner wall of the tank. The uppermost horizontal reinforcing ribs are arranged near the grain loading line, and the bottom of the vertical columns is implanted with a pad layer, resulting in high overall stability.

[0019] Equipment openings are located at positions corresponding to the outlet channels of the tank body. A grain-blocking gate is located directly above the equipment openings. The tank walls around the equipment openings and grain-blocking gate openings are reinforced with a frame-type structure, which has high strength and ensures the structural stability of the bulk grain silo. Attached Figure Description

[0020] Figure 1 A schematic diagram of the planar distribution structure of the top-entry system of the grain storage system; Figure 2 for Figure 1 Schematic diagram of the facade structure; Figure 3This is a floor plan of the warehouse outlet. Figure 4 for Figure 3 Sectional view of AA in the middle; Figure 5 This is a schematic diagram of the bottom plan structure of the grain storage system; Figure 6 This is a schematic diagram of the distribution structure of the ventilation trenches at the bottom of the warehouse; Figure 7 This is a structural diagram of the secondary outlet. Figure 8 This is a schematic diagram of the plan structure of the warehouse roof; Figure 9 This is a schematic diagram of the elevation structure of the side of the tank. Figure 10 This is a top view of the grain-blocking gate opening; Figure 11 Schematic diagram of the thermal insulation structure of the outer wall of the oil tank; Figure 12 for Figure 11 A magnified view of a section at point B in the middle; Figure 13 This is a schematic diagram of the distribution structure of the ring-shaped flat steel. Figure 14 This is a partial structural diagram of the vertical column in Example 2; Figure 15 This is a layout diagram of the oil tank area.

[0021] In the diagram: 1-Tank body, 2-Elevating tower, 3-Grain inlet, 4-Multi-point unloading machine, 5-Subbase, 51-Concrete subbase, 52-Soil subbase, 53-Reinforced concrete subbase, 54-Concrete blocks, 6-Outlet, 7-Outlet passage, 71-Reinforced concrete structural slab, 8-Scraper conveyor, 9-Multi-point feeding conveyor, 91-Maintenance platform, 10-Trestle bridge, 10-Support frame, 11-Vertical column, 12-Ventilation hole 2, 13-Equipment 14 Grain gate, 15 Reinforced structure, 16 Spiral cleaning machine, 17 Ring rib support, 18 Rock wool board, 19 Ring flat steel, 9-1 Ring rib 1, 19-2 Diagonal rib, 20 Ventilation trench, 201 Main trench, 202 Branch trench, 21 Color steel, 22 Manhole, 23 Ventilation hole 1, 24 Railing, 25 Wind-resistant ring, 26 Steel cone bucket, 27 Steel grating plate, 28 Horizontal reinforcing rib, 29 Trench ventilation opening. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example 1

[0023] An oil tank to bulk grain storage system is proposed, which transforms an oil tank area into a bulk grain storage system. In this embodiment, the transformed oil tank area includes 10 large vegetable oil storage tanks arranged in a 2×5 matrix, with 2 tanks horizontally and 5 vertically. See the layout diagram. Figure 15 As shown, the original design volume of the oil tank was 11,156 m³, with an inner diameter of 27.20 m, a tank wall height of 21.00 m, and a total height of 24.266 m. Inspection revealed that the original tank's main structure had a safety rating of Level II (Class B), and its current condition is good, making it suitable for conversion into a bulk grain silo.

[0024] The aforementioned grain storage system includes multiple tanks arranged in the tank area, an inlet system, an outlet system, and a ventilation system.

[0025] See the structure of tank 1. Figure 3 and 4 As shown, the feed inlet of tank 1 serves as the grain inlet 3. Multiple horizontal reinforcing ribs 28 and multiple vertical columns 11 are evenly arranged inside the oil tank 1. In this embodiment, there are three annular horizontal reinforcing ribs 28, each running around the inner wall of the oil tank, with elevations of 7.3, 11.8, and 16.3 m respectively. That is, the uppermost horizontal reinforcing rib 28 is located near the grain loading line. There are eight vertical columns 11. The horizontal reinforcing ribs 28 and vertical columns 11 are welded to the inner wall of the oil tank through node plates. At their junction, a connecting plate is fixed on the horizontal reinforcing rib 28 and fixed to the vertical column 7 through bolts to achieve structural reinforcement of the oil tank.

[0026] See warehouse entry system Figure 1-2 As shown, a grain lifting tower 2 is first arranged on the side of the oil tank area. A horizontal and vertical trestle 10 is set on the top of the grain inlet 3. In this embodiment, there are two vertical trestle bridges, which are arranged on the top of the vertically distributed oil tanks. The middle of the vertical trestle bridge is connected to the horizontal trestle bridge, and the horizontal trestle bridge is connected to the grain lifting tower 2. A multi-point unloading machine 4 is arranged on the trestle 10. The discharge port of the multi-point unloading machine 4 is connected to the grain inlet 3 of the oil tank, forming the grain storage system's inlet system. In order to reduce the pressure of the trestle 10 on the oil tank 1, a support frame 10-1 is set at the position of the trestle 10 between the two oil tanks. The entire trestle bridge is supported by multiple support frames 10-1, thereby reducing the pressure on the tank body.

[0027] See outbound system Figure 3-5 A three-layer cushion layer 5 is laid at the bottom of tank body 1, with a total height of 2.6m. The bottom layer is a concrete cushion layer 51, 120mm thick; the middle layer is a compacted soil cushion layer 52 (compaction coefficient ≥0.94); and the top layer is a reinforced concrete cushion layer 53, 200mm thick, reinforced with double-layer, bidirectional Φ10@150*150 steel mesh. During the initial setting of the top layer, a 3mm thick layer of antistatic, non-sparking, wear-resistant aggregate is spread on its surface, smoothed immediately after application, with an aggregate dosage of 6kg / m³. 2A concrete block 54 is laid between the soil cushion layer 5 and the inner wall of the oil tank 1. The cross-sectional width of the block is 500mm. It is used to protect the inner wall of the tank body 1. The inner wall of the oil tank at the contact point with the concrete block 54 is coated with asphalt anti-corrosion oil.

[0028] Multiple outlets 6 are evenly arranged along the center line of the top of the foundation layer 5. Below the outlets 6 is the outlet channel 7, which measures 2.5*2m. The walls of the outlet channel 7 are made of reinforced concrete structural slabs 71 (300mm thick). The reinforcing bars in the reinforced concrete foundation layer 53 are anchored into the walls of the outlet channel 7. A scraper conveyor 8 is installed inside the outlet channel 7, and the lower end of the outlets 6 is connected to the inlet of the scraper conveyor 8.

[0029] A multi-point feeding conveyor 9 is arranged longitudinally in the middle of the oil tank area. The final discharge port of the scraper conveyor 8 at the bottom of each tank 1 is connected to the multi-point feeding conveyor 9. For convenient maintenance, the scraper conveyors 8 at the bottom of the two oil tanks farthest from the multi-point feeding conveyor 9 are used to collect materials to the multi-point feeding conveyor 9. A maintenance platform 91 is set below the material collection point. The other scraper conveyors 8, which are symmetrically distributed on both sides of the multi-point feeding conveyor 9, are staggered and form an angle of 3° with the horizontal direction, forming a bulk grain discharge system.

[0030] Each scraper conveyor 8 is equipped with a maintenance platform 91 at its head for daily maintenance and repair. The arrangement of the scraper conveyor 8 and the multi-point feeding conveyor 9 in this application does not change the original layout of the oil tank area; on the other hand, it can minimize the travel of bulk grain and ensure smooth transportation.

[0031] See Figure 6-7 The outlets 6 are distributed along the direction of the scraper conveyor 8 at the bottom of the silo. The outlet 6 located at the center of the silo bottom is the main outlet, and the other outlets are secondary outlets. The main outlet is formed by installing a steel plate cylinder through a pre-reserved opening in the reinforced concrete structural slab 71. A steel grid plate 27 is installed on the top of the outlet 6, and a spiral cleaning machine 16 is installed on the steel grid plate 27 at the top of the main outlet. That is, the spiral cleaning machine 16 can move in a circular motion along the main outlet to clean the loose grain at the bottom of the silo into the outlet. For the specific structure of the secondary outlets, see [link to details]. Figure 7 As shown, a steel cone bucket 26 is installed inside the outlet 6, and a steel grid plate 27 is directly above the steel cone bucket 26. The bottom of the steel cone bucket is connected to the feed port of the scraper conveyor 8 for easy discharge.

[0032] Ventilation system: Ventilation troughs 20 are installed on the cushion layer 5. In this application, there are two sets of ventilation troughs, which are symmetrically distributed on both sides of the corresponding warehouse outlet channel 7 on the cushion layer 5. The ventilation troughs include a main trough 201 and multiple branch troughs 202 connected to it. The ventilation troughs 20 are connected to the external fans through the trough ventilation openings 29 to form a ventilation system at the bottom of the warehouse. It is equivalent to the bottom of the warehouse having two sets of ventilation troughs. Centrifugal fans can be used for ventilation. The power of a single fan is 11kW, the air volume is 11482m³ / h, and the air pressure is 2477Pa, which can meet the requirement that the unit ventilation volume of wheat is not less than 6m³ / ht.

[0033] See Figure 8 As shown, a manhole 22 and multiple ventilation holes 23 are provided on the top of the oil tank 1. The manhole 22 is 1m away from the outer perimeter of the top of the oil tank 1. In this embodiment, there are a total of four ventilation holes 23. The two outer ventilation holes are located 2.1m away from the edge of the oil tank 1 and serve as natural ventilation openings. The inner ventilation hole is located 2m away from the center of the oil tank and is connected to an axial flow fan. Together with the ventilation system at the bottom of the silo, they form a circulating ventilation system for the bulk grain silo, which can achieve the effect of ventilation and cooling.

[0034] See Figure 9-10 As shown, the outlet of the scraper conveyor 8 is the equipment opening 13, and a grain retaining door 14 is installed directly above the equipment opening 13. Both the equipment opening 13 and the grain retaining door 14 are surrounded by reinforcing structures 15. These reinforcing structures 15 are frame-type reinforcing structures formed by fixing channel steel along the horizontal and vertical directions. These reinforcing structures are fixed to the tank walls around the equipment opening 13 and the grain retaining door 14, symmetrically distributed on both sides of the tank walls. They are fixed to the tank walls with high-strength bolts, resulting in strong overall stability and reinforcing the doorway structure, reducing the impact of the doorway on the tank structure.

[0035] See Figure 11-13 As shown, annular flat steel bars 19 are evenly arranged on the outside of oil tank 1 and on the top of the tank. The spacing between the annular flat steel bars on the tank wall is 400mm, and the spacing on the top of the tank is 300mm, forming annular support. The annular flat steel bars 19 are fixed to the tank wall by multiple ring rib supports 17. An insulation strip is laid between two annular flat steel bars 19. The insulation strip is made of 50mm thick rock wool board 18, which is laid in two layers with staggered joints to form an insulation strip. Two ring ribs 19-1 are horizontally tied on the outside of the insulation strip, and then V-shaped binding is done with diagonal ribs 19-2. The width of the V-shape is about 500mm. The ring ribs are steel bars, and the diagonal ribs are steel wires, which has high overall stability. The outermost layer is covered with 0.5mm color steel plate 21.

[0036] Additionally, wind-resistant rings 25 are installed on the outside of the oil tank at elevations of 15.5m and 18.5m above and below the grain loading line, respectively, and railings 24 are welded to the outer perimeter of the top of the oil tank for protection.

[0037] After the above modifications were completed, the cross-sectional strength, wall stability, and overall stability of the modified bulk grain silo were verified in accordance with GB50884-2013, GB50322-2011, GB50341-2014, and GB5009-2012. The storage material was wheat, the bulk grain loading height was 16.5m, the silo diameter was 27.2, the storage density was 8KN / m³, the internal friction angle was 25°, the friction coefficient with the steel plate was 0.3, the lateral pressure coefficient was 0.406, the hydraulic radius of the cross-section was 6.8, the design value of the steel plate strength was 205N / mm, the vertical pressure correction coefficient was 1, the design value of the wind pressure was 1.2KN / ㎡, the design value of the silo top load was 1.4, and the thickness of the reserved wear layer was 2mm.

[0038] 1. First, perform stress calculations on the modified bulk grain silo: (1) Standard value of grain horizontal pressure P hK ; Calculate the standard value of the horizontal pressure per unit area on the silo wall at a depth S (S = 16.5m) for shallow silo, deep silo, and flow conditions respectively, and take the maximum value. γ Grain density (kN / m³), K (lateral pressure coefficient), μ : Coefficient of friction between grain and silo wall, ρ hydraulic radius, C h Deep warehouse dynamic pressure correction coefficient.

[0039] Asakura: P hK =kγs=0.4059*8*16.5=53.6KN / ㎡ Deep storage: P hK = C h γρ (1−e −μks / ρ ) / μ=2*8*6.8*(1-e^(-0.3*0.4059*16.5 / 6.8)) / 0.3=92.8KN / ㎡ Flow regime: P hk =0.6γS=0.6*8*16.5=79.2KN / ㎡ Take the largest one, P hK =92.8 KN / ㎡ (2) Standard value of vertical friction force P of grain fk calculate: Calculate the standard value of the vertical frictional force per unit area of ​​the silo wall at depth s: P fk =μkγs=0.3*0.4059*8*16.5=16.1KN / ㎡ Calculate the standard value of the total vertical friction force per unit perimeter of the silo wall at depth s: q fk =½kμγs 2==0.5*0.4059*0.3*8*16.5^2=132.6KN / m (3) Calculate the wind load w k w k =β z μ s μ z w0 =1.25*0.8*1.23*0.5=0.615KN / ㎡ (4) Calculate the snow load S k Standard value of snow load S k =1*0.4=0.4 KN / ㎡ (5) The self-weight of the tank top is 400kN (6) Live load on tank top: 0.5 kN / m² 2. Combination of loads on the silo wall (1) Design value of horizontal pressure P of the silo wall hK Calculate: P h =1.3P hK =1.3 * 92.8 = 120.6 KN / ㎡ (2) Basic combination of vertical pressure per unit perimeter of the silo wall: Standard value of total vertical friction force of the silo wall = 132.6 kN / m The standard vertical force on the silo wall caused by the self-weight of the silo wall and silo roof is calculated as follows: 400 / (3.14*27.2) + 78.2*0.02*18.4 = 33.6 kN / m The standard value of the vertical force on the silo wall caused by the live load on the silo roof = (0.5 * 0.25 * 3.14 * 27.2) 2 ) / (3.14*27.2)=3.4KN / m The vertical force on the silo wall caused by the wind load on the silo roof is calculated as follows: (0.615 * 0.25 * 3.14 * 27.2) 2 ) / (3.14*27.2)=4.2KN / m The standard value of the vertical force on the silo wall caused by the snow load on the silo roof = (0.4 * 0.25 * 3.14 * 27.2) 2 ) / (3.14*27.2)=2.7KN / m No wind load: q v =1.2q gk +1.3q fk +1.4Σϕ i q Qik q v =1.3*33.6+1.3*132.6+1.5*(3.4+2.7)=225.21kN / m Wind load: qv =1.2q gk +1.3q fk +1.4*0.6Σ(q) wk+ q Qik ) q v =1.3*33.6+1.3*132.6+1.5*0.6*(3.4+4.2+2.7)=225.33kN / m Therefore, the design value for vertical pressure is taken as 225.33 kN / m.

[0040] Based on the above data, the cross-section of the bulk grain silo wall, the stability of the silo wall under vertical force (empty and full conditions), and the stability of the empty silo under wind load were verified. The stress conditions of equipment passageways, cavities, and the bottom plate were also calculated. The calculated results show that the modified bulk grain silo fully meets the requirements for bulk grain storage. After modification, the grain loading height of the tank is 16.5 meters. The grain storage system in this embodiment is expected to store 77,000 tons of bulk grain (based on wheat). Moreover, compared to demolishing and rebuilding an oil tank area into a bulk grain silo, the construction cost and construction period of this application are significantly reduced, making it suitable for large-scale promotion and application.

[0041] After construction is completed, the bulk grain in the grain silo will be filled in four stages for the first time, with the amount of grain in each stage being 50%, 20%, 20%, and 10% respectively. After each stage of grain filling is completed, the grain should be left to stand for a certain period of time. The standing time after the first three stages of grain filling should not be less than one month. During the standing period, settlement observation should be carried out. The tilt rate caused by uneven settlement along the length and width of each group of silos should not be greater than 0.002. Only if the observation results meet the requirements can the next stage be carried out. The phased grain filling in this application can meet the requirements. After the trial filling is completed, normal grain storage can be carried out.

[0042] The above-mentioned grain storage system's methods for entering and leaving the warehouse include the following steps: 1) Grain entry method: After unpacking and inspection, the grain is unloaded into the receiving system by the hydraulic tipping unloading device. It is then transported to the lifting system by the mobile receiving belt conveyor. The bulk grain is lifted by the grain lifting tower 2 to the multi-point unloading machine 4 on the trestle, and enters the tank 1 through the discharge port and grain inlet 3 of the multi-point unloading machine 4 in sequence. During the storage of bulk grain, the bottom fan or the axial flow fan on the top of the tank can be turned on as needed to achieve ventilation inside the tank. 2) Unloading method: Open the unloading port 6, and the bulk grain flows into the scraper conveyor by gravity through the unloading port 6. After passing through the scraper conveyor, it enters the multi-point feeding conveyor 9 and is further transported to the unloading pit or to other processes. It can realize automated loading and unloading. The cleaning operation at the bottom of the warehouse is realized by the spiral cleaning machine 16. Example 2

[0043] See Figure 14As shown, the vertical column 11 can adopt a hollow structure. In this embodiment, it is a hollow steel pipe. Ventilation holes 12 are evenly arranged on the inner side of its upper part (from one-third of the grain loading line to the grain loading line). The upper part of the vertical column 11 is connected to the external fan through the ventilation pipe, which increases the lateral ventilation effect of the bulk grain in the tank and increases the overall ventilation effect of this application.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A system for converting oil tanks into bulk grain storage facilities, characterized in that, This includes multiple tanks (1) located in the tank area, an inlet system, an outlet system, and a ventilation system; The feed inlet of the tank (1) serves as the grain inlet (3), and multiple horizontal reinforcing ribs (28) and multiple vertical columns (11) are evenly arranged on the inner side. Grain loading system: A grain lifting tower (2) is arranged on the side of the oil tank area. A horizontal and vertical trestle (10) is set on the top of the grain inlet (3). The trestle (10) is connected to the grain lifting tower (2). A multi-point unloading machine (4) is arranged on the trestle (10). The discharge port of the multi-point unloading machine (4) is connected to the grain inlet (3) to form a bulk grain loading system. Outlet system: A pad layer (5) is laid at the bottom of the tank (1), and multiple outlets (6) are evenly arranged on the center line of the top of the pad layer (5). An outlet channel (7) is set below the outlet (6). A scraper conveyor (8) is set in the outlet channel (7). A multi-point feeding conveyor (9) is set in the middle of the oil tank area. The discharge port of the scraper conveyor (8) is connected to the multi-point feeding conveyor (9) to form an outlet system for bulk grain. Ventilation system: Multiple ventilation holes (23) are provided on the top of the tank (1), and ventilation trenches (20) are provided on the pad layer (5).

2. The oil tank-to-bulk grain storage system according to claim 1, characterized in that, The vertical column (11) is a hollow structure with two ventilation holes (12) evenly arranged on the upper inner side. The upper part of the vertical column (11) is connected to the external fan.

3. The oil tank-to-bulk grain storage system according to claim 1, characterized in that, The outlet of the warehouse passage (7) is the equipment port (13), and a grain blocking door (14) is set above the equipment port (13).

4. The oil tank-to-bulk grain storage system according to claim 3, characterized in that, The equipment opening (13) and the grain gate (14) are surrounded by a reinforcing structure (15).

5. The oil tank-to-bulk grain storage system according to claim 1, characterized in that, The foundation layer (5) consists of three layers, from bottom to top: concrete foundation layer (51), soil foundation layer (52) and reinforced concrete foundation layer (53). The walls of the exit passage (7) are reinforced concrete structural slabs, and the steel bars in the reinforced concrete foundation layer (53) are anchored into the walls of the exit passage (7).

6. The oil tank-to-bulk grain storage system according to claim 1, characterized in that, A ventilation trough (20) is provided on the cushion layer (5) and connected to the external fan.

7. The oil tank-to-bulk grain storage system according to claim 1, characterized in that, The outlet (6) located at the center of the warehouse bottom is the main outlet, and the other outlets are secondary outlets. A steel grid plate (27) is installed at the top of the outlet (6), and a spiral cleaning machine (16) is installed on the steel grid plate (27) above the main outlet.

8. The oil tank-to-bulk grain storage system according to claim 1, characterized in that, The tank body (1) has evenly distributed ring flat steel (19) on the outside. Insulation strips are laid between the ring flat steel (19). The outer side of the insulation strip is fixed with ring reinforcement (19-1) and then fixed in a V-shape with diagonal reinforcement (19-2). The outermost layer is covered with color steel plate (21).

9. A method for loading and unloading grain into a tank-to-bulk grain storage system as described in claim 1, comprising the following steps: 1) The bulk grain is lifted by the grain lifting tower (2) to the multi-point unloading machine (4) on the trestle, and enters the tank (1) through the discharge port and grain inlet (3) of the multi-point unloading machine (4); 2) Open the outlet (6), and the bulk grain enters the scraper conveyor (8). After passing through the scraper conveyor (8), it enters the multi-point feeding conveyor (9) and is transported to the next process.

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