A screening and discharging device of a frozen pulverizer

Abstract

The utility model provides a kind of screening and discharging device of frozen pulverizer, it is characterized in that, including: cooling heat preservation shell, at least one layer of vibrating screen is provided with in the bottom of the cooling heat preservation shell inclination;Low-temperature elastic retaining mechanism is equipped in the vibrating screen bottom and in the heat preservation shell, the low-temperature elastic retaining mechanism is composed of hollow nitrogen-filled elastic ball and closed copper pipe with micropore, the back of the screen is arranged with "hui zi shape" micropore copper pipe and hollow nitrogen-filled elastic ball in the application, copper pipe is connected into dry compressed air to form local air cushion, so that elastic ball still keeps high resilience and continuously impacts the back of the screen at-30 DEG C, realize low-temperature anti-blocking screen cleaning;Copper pipe is welded and fixed with screen frame, vibrating synchronously with screen, without additional drive, it is applicable to diatomite, perlite and other frozen brittle oil-absorbing materials Dust-free, efficient, multi-specification continuous production.

Description

Technical Field

[0001] This utility model relates to the technical field of environmentally friendly material processing equipment, specifically a screening and feeding device for a cryogenic pulverizer. Background Technology

[0002] In the production process of environmentally friendly oil-absorbing materials (such as OLOC oil-absorbing granules), raw materials need to undergo cryogenic pulverization to achieve the required particle size range and physical properties. Cryogenic pulverizers embrittle materials at low temperatures, making them easier to pulverize. They are particularly suitable for screening and feeding particles after cryogenic pulverization of oil-absorbing materials (such as diatomaceous earth, perlite, etc.).

[0003] For example, a publicly disclosed method for preparing a high-efficiency graphene oil-absorbing material (patent number CN2020109470968) involves reacting graphite powder raw material with concentrated sulfuric acid to obtain brown graphite flakes with derived carboxylic acid groups at the edges and mainly phenolic hydroxyl and epoxy groups on the plane. The graphene flakes are then pulverized to form particles, and the obtained particles are added to deionized water. After sonication for 2-5 hours, a uniformly dispersed graphene oxide aqueous solution is obtained. Polyvinylidene fluoride is added to a dimethylamide solution and reacted fully at 50-100℃ with stirring for 0.4-2 hours to obtain a completely dissolved mixed liquid. The mixed solution obtained in step 2) is added to the graphene oxide aqueous solution and mixed and stirred for 20-50 minutes. Then, a nitrogen-containing reducing agent is added and reacted fully at a temperature of 120-200℃. After the reaction is completed, a hydrogel is obtained by hydrothermal reduction. The hydrogel is washed with deionized water to remove residual polyvinylidene fluoride, and then the product is freeze-dried to obtain a porous, high-efficiency graphene oil-absorbing material. However, existing cryogenic grinders generally have the following problems after grinding: Low screening efficiency: The particle size distribution of the crushed particles is uneven, and traditional screening devices are prone to clogging, making it difficult to achieve efficient classification. Poor feeding: After low-temperature grinding, moisture or oil may remain on the surface of the particles, causing them to stick together and affecting the smooth feeding process. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a screening and feeding device for a cryogenic pulverizer.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a screening and feeding device for a cryogenic pulverizer, characterized in that it includes: a cooling and heat-insulating outer shell, at least one layer of vibrating screen is inclinedly provided at the bottom of the cooling and heat-insulating outer shell; a low-temperature elastic holding mechanism is provided at the bottom of the vibrating screen and inside the heat-insulating outer shell, the low-temperature elastic holding mechanism is composed of a hollow nitrogen-filled elastic ball and a closed copper tube with micropores, the closed copper tube is filled with dry compressed air to form an air cushion layer, so that the elastic ball keeps rebounding and continuously impacts the back of the screen.

[0006] As a preferred embodiment of this application, the hollow elastic sphere is made of EPDM, with a wall thickness of 0.8-1.2 mm, and is filled with nitrogen gas at 0.1-0.2 MPa.

[0007] As a preferred embodiment of this application, the upper surface of the closed copper tube is evenly distributed with micropores of φ0.5-1 mm and the hole spacing is 10-15 mm.

[0008] As a preferred embodiment of this application, the closed copper tube is arranged in a loop-shaped closed form on the back of the vibrating screen.

[0009] As a preferred embodiment of this application, the closed copper tube is welded and fixed to the frame wall of the vibrating screen and vibrates synchronously with the vibrating screen.

[0010] As a preferred embodiment of this application, a vertical gap of at least 5 mm is left between the vibrating screen and the closed copper tube.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: The hollow nitrogen-filled elastic ball in the low-temperature elastic holding mechanism of this application continuously impacts the back of the screen under the action of the air cushion layer. This impact provides additional vibration power to the screen, allowing the material to roll and jump more fully on the screen, thereby accelerating the speed at which the material passes through the screen and significantly improving the screening efficiency. Moreover, the uniform and strong vibration can better disperse the material and reduce the phenomenon of mutual adhesion between material particles and clogging of the screen holes. Attached Figure Description

[0012] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the main structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the closed copper tube planar structure of this utility model.

[0013] In the diagram: 1. Cooling and heat preservation shell; 2. Vibrating screen; 3. Elastic ball; 4. Closed copper tube. Detailed Implementation

[0014] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0015] like Figure 1-3 As shown, this application provides a screening and feeding device for a cryogenic pulverizer. This application solution is mainly applied to the specific production line of cryogenic pulverization + oil-absorbing materials. In high-value-added, small-batch, multi-specification scenarios such as cryogenic embrittlement + oil-absorbing materials, this device can reduce the "blockage every 20 minutes" to a tower, thereby increasing the output. This is its practicality and functional amplifier effect, demonstrating its indispensable practicality. If the "low-temperature elastic air cushion ball" screening device is regarded as a general-purpose sieve, it does seem to have "excessive functions". It includes: a cooling and heat-insulating shell 1, at least one layer of vibrating screen 2 is inclined at the bottom of the cooling and heat-insulating shell 1; a low-temperature elastic holding mechanism is provided at the bottom of the vibrating screen 2 and inside the heat-insulating shell. The low-temperature elastic holding mechanism consists of a hollow nitrogen-filled elastic ball 3 and a closed copper tube 4 with micropores. Dry compressed air is introduced into the closed copper tube 4 to form an air cushion layer, so that the elastic ball 3 keeps rebounding and continuously impacts the back of the screen.

[0016] The screen is installed at an overall tilt of 6–8°, and the vibration motor performs high-frequency elliptical vibration. The powder is thrown up on the surface of the sieve → slides forward → and falls back onto the sieve surface, moving forward in a "jumping" manner; Only particles with a diameter smaller than the current sieve opening will be flung through the opening at the moment of contact with the sieve and fall obliquely to the next layer. Therefore, the macroscopic trajectory is a combination of oblique projection and sliding, rather than a purely vertical path.

[0017] in conclusion: The powder travels from the high end to the low end, and when it passes through the sieve holes, it is obliquely downward. The angle is approximately equal to the sieve tilt angle plus the vibration projection angle. It will never fall vertically at 90°, nor will it be pushed back by the microporous airflow.

[0018] This device has an opening ratio of 28-32% (the best in the industry), which ensures both the screening volume and sufficient solidity for the spheres to "have a place to collide"; The sphere, with a diameter of 25 mm, always spans the "solid bridge" between 4-6 holes, preventing blockage and instead dislodging powder particles stuck in the holes.

[0019] ② Moment of startup The PLC first opens the "cleaning solenoid valve" → 0.2 MPa dry air enters the copper tube 4 → a jet of 15 m / s is sprayed upward through the micro-hole.

[0020] The bottom of the sphere is immediately subjected to an upward pressure of ≥0.02 MPa (calculated area 50 mm² × 0.02 MPa = 1N, which is greater than the weight of the sphere by 0.025 N), and is momentarily lifted 1-2 mm, detaching from the top of the tube—the previously covered hole immediately opens to release air, and the sphere enters the working state.

[0021] Even if the sphere deviates by ±2 mm at the landing point, a new row of micropores will appear around it, and it will continue to be blown up. There is no such thing as "it won't move if it's not aligned".

[0022] ③ Operation period Vibration motor 15 Hz elliptical vibration → The ball jumps up and down within a height of 1-2 mm, with a horizontal drift of ±2 mm / cycle, which is still much smaller than the hole spacing of 12 mm. Statistically, it will always straddle ≥3 holes. The jetting and vibration phases are fixedly coupled by the PLC (valve open 50 ms → impact peak), ensuring that when the ball falls back after each impact, it still lands in the same row of micropores, forming a dynamic steady state.

[0023] Actually, it's a "closed-loop coil"—a copper tube 4 is folded back and forth into 5-6 parallel branch tubes, with a center-to-center distance of 60 mm between the branch tubes. The whole is still a closed loop, and its appearance looks like a "comb". Therefore, any ball is ≤30 mm away from the nearest branch tube and falls between at least 2 branch tubes, achieving full screen coverage. The "closed-loop copper tube 4" only stays on the back of the top layer of screen. Its task is to "let the ball continuously hit the steel plate → loosen the powder stuck in the holes"; what really allows the powder to penetrate downwards is still the 2 mm screen holes on the steel plate—these holes are all over the entire screen surface, including the "blank area" between the two copper tubes 4 branch tubes.

[0024] The branch pipe is 6 mm wide and the center distance is 60 mm → the net width between the two pipes is 54 mm, which is filled with screen holes and occupies more than 90% of the screen surface; The steel pipe sprays air at a 5 mm gap on the back, the airflow is upward and does not obstruct the powder from passing through the sieve downward; The powder is thrown up by elliptical vibration → slides forward → can be perforated in any hole area at the moment of contact with the mesh, which does not conflict with the presence or absence of copper pipes and four branches; The measured screening efficiency was 97%, which is consistent with the theoretical opening rate, proving that the "branch pipe shadow" does not affect the screening.

[0025] in conclusion: Copper tube 4 is just a "cleaning robot". The powder still falls freely from more than 90% of the mesh surface, and the fine powder is still screened off.

[0026] Implementation principle: The inner wall of the cooling and insulation shell 1 is filled with 50 mm thick PIR foam with a thermal conductivity ≤0.022 W / (m·K), keeping the temperature inside the cavity between 0 ℃ and -30 ℃; the vibrating screen 2 is tilted at 8° and driven by two 0.25 kW vibrating motors (YZS-1.5-2, 380 V, 3000 rpm), generating an elliptical vibration trajectory; the low-temperature elastic holding mechanism is located on the back of the uppermost screen, forming a local positive pressure air cushion through "hollow nitrogen-filled elastic ball 3 + U-shaped microporous copper tube 4", which lifts the ball by 1-2 mm and continuously impacts the back of the screen, loosening the powder particles stuck in the holes.

[0027] Workflow: Cryogenic pulverizer → Cooling and insulation shell 1 feed inlet → Inclined vibrating screen 2 (grading) → Qualified particles pass through the screen → Feed channel → Loss-in-weight weighing collection bin; Unqualified particles continue to slide forward until they are perforated or discharged at the end.

[0028] Reference models: Vibration motor YZS-1.5-2; Cooling unit Copeland ZB15KQE-PFJ, R404A refrigerant, cooling capacity 2.8 kW @ -25 ℃.

[0029] Power supply implementation: 380 V AC three-phase five-wire system, total power 3 kW; compressed air is supplied from the on-site 0.6 MPa main pipe, cooled to -15 ℃ and 0.2 MPa by a refrigerated dryer (SMC IDG30A-03) and then connected to copper pipe 4.

[0030] Processor operation: The PLC (Siemens S7-1200 CPU 1212C) acquires the cavity temperature through the analog module AI 2×RTD, and the PID controls the opening of the refrigerant electronic expansion valve; the vibration motor is directly driven by the DO point to start and stop, and the operating current is ≤0.8 A.

[0031] "Densely packed needle-eye tubes + hollow ping-pong ball" = No matter where the ball lands, it will always cover several needle-eye tubes; once air is released, it is instantly supported by the collective upward water column and enters the net-cleaning cycle again - without motors, guide rails, or zero alignment, the pure mechanical probability steady state can achieve "instant stop and cover, instant blow and start".

[0032] The screen size is provided according to the commonly used specifications of the "upper main screen". It can be ordered directly or scaled parametrically along with the forming tube. Effective area of ​​mesh 500 mm (width) × 400 mm (length), the same size as the outer frame of the U-shaped copper tube, with a 20 mm edge.

[0033] thickness 1.0 mm 304 stainless steel sheet, laser punched and deburred to ensure impact energy transfer.

[0034] Aperture / Open Area Ratio (Three-layer Configuration) Top layer: φ2.0 mm, equilateral triangular arrangement, hole spacing 3 mm → Opening ratio 32% Middle layer: φ1.0 mm, hole spacing 2 mm → Opening ratio 28% Bottom layer: φ0.5 mm, hole spacing 1.2 mm → Opening ratio 26% frame A 20 × 20 × 2 mm square tube welded frame is bolted to the vibratory motor support; φ6 mm copper tube lugs (60 mm spacing) are welded to the outside of the frame.

[0035] tolerance Hole diameter ±0.02 mm, hole spacing ±0.05 mm, and overall plate flatness ≤0.3 mm / 500 mm, ensuring flatness even after low-temperature shrinkage.

[0036] Parameterization capability When the forming tube is reshaped (bag width 350 → 450 mm), the SolidWorks design table scales the screen width and length synchronously, and the laser cutting machine completes the new plate in 10 minutes without the need to open a new mold.

[0037] The hollow elastic sphere 3 is made of EPDM, with a wall thickness of 0.8-1.2 mm, and is filled with 0.1-0.2 MPa nitrogen gas.

[0038] Implementation principle: The elastic ball 3 is made of low-temperature grade EPDM (Lanxess Keltan 8550C) with a glass transition temperature of -52 ℃; the ball wall thickness is 1.0 mm, and the interior is filled with 0.15 MPa nitrogen gas (purity 99.9%), so that the ball's rebound rate is still ≥55% at -30 ℃ (GB / T 1681).

[0039] Work process: Before starting the machine, use a miniature nitrogen cylinder (2 L, 15 MPa) to fill the sphere with gas through the needle valve → the pressure gauge is locked after reaching 0.15 MPa; during operation, the sphere is floated by the air cushion → impacts the screen → nitrogen buffers → no deformation.

[0040] Reference models: EPDM sphere (customized φ25×1 mm); nitrogen cylinder (WMA-219-15-2); needle valve (SS-1RS4).

[0041] Energy supply implementation: A single nitrogen charge can provide continuous use for 1200 hours, eliminating the need for continuous gas supply on site.

[0042] Processor operation: The PLC does not directly monitor nitrogen pressure; the fatigue life of the sphere is reminded by the maintenance software (a replacement prompt will pop up after 1200 hours of operation).

[0043] The upper surface of the closed copper tube 4 is evenly distributed with micropores of φ0.5-1 mm, and the hole spacing is 10-15 mm.

[0044] Implementation principle: The upper surface of copper tube 4 (C12200 oxygen-free copper) is laser-drilled with a diameter of φ0.8 mm and a hole spacing of 12 mm, and the holes are evenly distributed in a single row at 360°. The flow rate of a single hole is 0.8 L / min@0.2 MPa, which creates an upward wind speed of 15 m / s, which is sufficient to support a 2.5 g sphere.

[0045] Workflow: Compressed air → Precision pressure reducing valve (SMC IRV20-C06) → Copper tube 4 → Micro-hole upward air jet → Formation of 1-2 mm air cushion layer → Ball jump.

[0046] Recommended models: Pressure reducing valve IRV20-C06; Flow meter LZB-3WB 0.1-1 L / min.

[0047] Energy supply implementation: The compressed air in the plant is reduced from 0.6 MPa to 0.2 MPa after passing through a refrigerated dryer, with an air consumption of 18 L / min (0.4 m³ / h) and an electricity cost of approximately 0.02 yuan / h.

[0048] Processor operation: The PLC controls the current of the pressure reducing valve coil through the AO point to achieve stepless adjustment from 0.1 to 0.3 MPa; the wind speed is fed back by the differential pressure sensor (SMC PSE530) with a closed-loop accuracy of ±2 kPa.

[0049] Beneficial effects: After optimization of aperture / pore spacing, the uniformity of air cushion CV is less than 5%, the horizontal drift of the ball is less than 2 mm, and the net cleaning efficiency is improved by 40%.

[0050] The closed copper tube 4 is arranged in a loop shape on the back of the vibrating screen 2.

[0051] Implementation principle: A copper tube is bent into a 500×400 mm loop frame with a radius of 20 mm at each corner. The weld seams are filled with silver brazing filler metal and the pressure is maintained at 0.6 MPa without leakage. The loop layout ensures that any sphere ≤80 mm in any area can reach the air jet hole.

[0052] Workflow: The sphere rolls randomly within the loop frame → it is supported by air cushions at any position → the net is cleared completely.

[0053] Reference model: CNC pipe bending machine DW38NC; silver brazing filler BAg-5.

[0054] Energy supply implementation: One-time bending and forming, with no additional energy consumption.

[0055] Processor operation: sensorless, purely mechanical structure.

[0056] Beneficial effects: Compared with straight single-row pipes, the netting coverage rate is increased from 65% to 98%, and the number of welds is reduced by 4 times, reducing the risk of leakage to zero.

[0057] The closed copper tube 4 is welded and fixed to the frame wall of the vibrating screen 2 and vibrates synchronously with the vibrating screen 2.

[0058] Implementation principle: The two ends of the copper tube 4 are welded to the side plate of the screen frame (TIG continuous welding), the weld length is 20 mm, and the shear strength is ≥150 MPa, ensuring that the copper tube 4 vibrates synchronously with the screen without relative displacement.

[0059] Workflow: Vibrating motor → screen frame → copper tube 4 → synchronous vibration of the ball, with an impact phase difference of <2 ms.

[0060] Recommended models: TIG welding machine WS-200A; welding wire ERCu.

[0061] Energy supply implementation: Welding energy consumption is 0.5 kWh / set, with a one-time investment.

[0062] Processor operation: no electrical connection, mechanical synchronization.

[0063] Beneficial effects: Elimination of relative wear increases the lifespan of the closed copper tube from 6 months to 3 years; synchronous vibration improves the ball impact efficiency by 25%.

[0064] A vertical gap of at least 5 mm is left between the vibrating screen 2 and the closed copper tube 4.

[0065] Implementation principle: A vertical gap of 5 mm (tolerance +0.5 / 0 mm) is designed between the back of the screen and the top of the copper tube to ensure: ① The ball should be lifted 1-2 mm without touching the net surface to avoid additional friction; ② The microporous jet can diffuse fully to form a uniform air cushion; ③ Leave a 2-3 mm safety distance to prevent the mesh from touching the pipe due to low temperature shrinkage.

[0066] Workflow: Use a 5 mm feeler gauge for positioning during assembly → spot welding → remove the feeler gauge → continuous welding.

[0067] Reference models: 5 mm feeler gauge GB / T 22523; HL-G1-A-C5 laser rangefinder sensor for online spot checks.

[0068] Energy supply implementation: purely mechanical positioning, with no additional energy consumption.

[0069] Processor operation: The PLC randomly inspects 10% of the batches using laser ranging; if the deviation exceeds the limit, an alarm is immediately triggered and the machine is shut down.

[0070] Beneficial effects: gap consistency CV < 3%, air cushion uniformity improved by 30%, ball wear decreased by 40%, and annual spare parts cost saved by 18,000 yuan.

[0071] Furthermore, this application only requires arranging a "low-temperature elastic retention mechanism" on the top layer, for the following reasons: Over 90% of the network congestion is caused by this. The top layer has the largest aperture (usually 2 mm), the largest amount of material, and the coarsest particles, making it the most prone to clogging. As long as this layer remains unobstructed, the middle and lower layers will hardly accumulate any material.

[0072] The lower layer is already in a state of "low material content + low moisture content". After being pre-screened in the upper layer, the powder particles entering the middle and lower layers are small in size and light in weight, and the surface free water has been carried away by the airflow, so they are not easy to clump together; ordinary rubber balls can meet the needs of net cleaning.

[0073] Cost and maintenance Adding copper pipes, quick-connect fittings, and air lines to each layer would increase the overall cost of the machine by 30% and the number of potential failure points by 3 times; the utility model emphasizes "limited" efficiency improvements, so these are only installed on the upper layer.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A screening and feeding device for a cryogenic pulverizer, characterized in that, include: A cooling and heat-insulating shell (1) is provided with at least one layer of vibrating screen (2) at the bottom of the cooling and heat-insulating shell (1); a low-temperature elastic holding mechanism is provided at the bottom of the vibrating screen (2) and inside the heat-insulating shell. The low-temperature elastic holding mechanism consists of a hollow nitrogen-filled elastic ball (3) and a closed copper tube (4) with micropores. Dry compressed air is introduced into the closed copper tube (4) to form an air cushion layer, so that the elastic ball (3) keeps rebounding and continuously impacts the back of the screen.

2. The screening and feeding device for a cryogenic pulverizer as described in claim 1, characterized in that, The elastic ball (3) is made of EPDM with a wall thickness of 0.8-1.2 mm and is filled with 0.1-0.2 MPa nitrogen.

3. The screening and feeding device for a cryogenic pulverizer as described in claim 2, characterized in that, The upper surface of the closed copper tube (4) is evenly distributed with φ0.5-1 mm micropores, with a hole spacing of 10-15 mm.

4. The screening and feeding device for a cryogenic pulverizer as described in claim 3, characterized in that, The closed copper tube (4) is arranged in a loop shape on the back of the vibrating screen (2).

5. The screening and feeding device for a cryogenic pulverizer as described in claim 1, characterized in that, The closed copper tube (4) is welded and fixed to the frame wall of the vibrating screen (2) and vibrates synchronously with the vibrating screen (2).

6. The screening and feeding device for a cryogenic pulverizer as described in claim 1, characterized in that, A vertical gap of at least 5 mm is left between the vibrating screen (2) and the closed copper tube (4).

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