Pretreatment equipment and process for raw materials of compression molding machine

Abstract

The invention relates to the technical field of mulching film treatment, in particular to pretreatment equipment for raw materials of a compression molding machine and a process of the pretreatment equipment. Comprising a hydraulic sudoku, a first-stage drum screen, a crusher, a second-stage drum screen, a first-stage winnowing machine, a second-stage winnowing machine, a stock bin and a compression molding machine which are sequentially connected, the crusher comprises a hopper, a machine base located at the bottom of the hopper and communicated with the hopper and two crushing cutter sets, and each crushing cutter set comprises a plurality of crushing cutters and a rotating shaft; the crushing cutter is installed in the machine base through a rotating shaft, an anti-winding mechanism is arranged in the machine base, the anti-winding mechanism comprises baffles, and the baffles are symmetrically arranged on the two sides in the machine base; according to pretreatment of the mulching film, dust and other impurities in the mulching film can be filtered out without cleaning, drying and other operations, compared with traditional cleaning, the filtering process saves water resources, the whole pretreatment process is automatically operated, participation of personnel is reduced, the labor amount is reduced, and the labor cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of ground film processing, and in particular to a pre-processing device for raw materials of a compression molding machine and a process thereof. Background Art

[0002] With the development of society, my country is the country with the largest amount of mulch film used and the largest coverage area in the world. About 1.45 million tons of mulch film is used every year, and the crop coverage area is nearly 300 million mu. The mulch film coverage has increased the crop yield by more than 30%. Xinjiang is the region with the largest mulch film planting area and the largest amount of mulch film used in my country. Every year, more than 2.45 million hectares of farmland are covered with about 150,000 tons of mulch film.

[0003] Recycling mulch to make pallets is a way of recycling agricultural waste into useful products, which helps reduce environmental pollution and create economic value. As a raw material for making pallets, mulch needs to be pre-treated to remove impurities before it is sent into the compression molding machine for extrusion, because the recycled mulch is mixed with impurities such as soil, stones, and straw. For the pretreatment of mulch, the traditional pretreatment method is to crush the mulch first, then clean it, and finally dry it. Due to the lack of water resources in Xinjiang, the cleaning process consumes a lot of water, which directly increases the production cost of the pallet. At the same time, when the mulch is crushed, because the mulch is soft and has strong tensile properties, there is a common problem that the shaft is entangled by the mulch, resulting in a slow speed or even stuck. In the crushing process, it cannot be cleaned in time, resulting in an increase in the load on the equipment, an increase in the extrusion friction between the mulch and the equipment, and a gradual increase in temperature, which can easily cause high temperature damage to the tool. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a pretreatment device and process for raw materials of a compression molding machine, which can remove impurities in recycled ground film without cleaning.

[0005] To achieve the above technical objectives, the present invention proposes the following technical solutions: a pretreatment device for raw materials of a compression molding machine, comprising a hydraulic nine-square grid, a primary drum screen, a crusher, a secondary drum screen, a primary air separator, a secondary air separator, a silo and a compression molding machine connected in sequence, the crusher comprising a hopper, a machine base located at the bottom of the hopper and connected to the hopper, and two groups of crushing knife groups, the crushing knife group comprising a plurality of crushing knives and a rotating shaft, the crushing knife is installed in the machine base through the rotating shaft, an anti-winding mechanism is provided in the machine base, the anti-winding mechanism comprises a baffle, the baffle is symmetrically arranged on both sides of the machine base, and the baffle is inclined toward the direction of the crushing knife group, a plurality of convex plates are provided on the baffle, the convex plate is located between two adjacent crushing knives, a cutting knife group is provided at the end of the convex plate, and an adjusting member for adjusting the telescopic extension of the cutting knife group is provided on the baffle; Furthermore, a sliding hole is opened on the side of the slide rail, and the adjusting member includes two groups, which respectively control the cutting knives on the two groups of cutting knife groups. The adjusting member includes a screw rod and an adjusting plate matched with the number of cutting knives. The adjusting plate is connected to the cutting knife through the sliding hole, and the screw rod is threadedly connected to the adjusting plate.

[0006] Furthermore, one end of the two screw rods passes through a side surface of the machine base and is connected to mutually meshing gears, and a handle is provided on any one of the screw rods.

[0007] Furthermore, the first-stage drum screen and the second-stage drum screen both include a support frame, a collecting cover is provided on the support frame, the drum screen is rotatably connected inside the collecting cover, and a dust removal cover is provided on the top of the collecting cover.

[0008] Furthermore, the first-stage air separator and the second-stage air separator both include a base, a cylinder, an air inlet duct and a centrifugal fan. The cylinder is arranged on the base, the air inlet duct is arranged on one side of the cylinder, and the centrifugal fan is connected to the top of the cylinder through an exhaust duct.

[0009] Furthermore, an inverted cone-shaped stopper is connected to the upper part of the cylinder via a support rod.

[0010] Furthermore, a process for a pretreatment device for a compression molding machine raw material includes the following steps: ① pre-dispersing the recycled plastic mulch mixture in a hydraulic nine-square grid, and conveying the dispersed plastic mulch mixture to a primary drum screen through a first chain plate to filter out sand or smaller stones and soil blocks mixed in the mulch; ② The mulch film screened in step ① is conveyed to the crusher through the first conveyor belt for crushing, and then conveyed to the secondary drum screen through the second chain plate after crushing to screen out large stones and soil blocks that are not screened out by the primary drum screen. The large stones and soil blocks are crushed by the crusher and then screened out by the secondary drum screen; ③ The material filtered by the secondary drum screen in step ② is sequentially passed through the primary air separator and the secondary air separator to extract the ground film; ④ The ground film extracted by air selection in step ③ is transported to a silo through a second conveyor belt for storage, so as to be heated and extruded by a compression molding machine.

[0011] Furthermore, the cutting knife group is provided with two groups, which are respectively arranged on the two end surfaces of the convex plate. The cutting knife group includes a cutting knife and a slide rail. The blade of the cutting knife faces the direction of the rotating shaft. The cutting knife is slidably installed in the slide rail. The adjustment member drives the two groups of cutting knife groups to move relative to or away from each other.

[0012] Furthermore, in step ③, a third conveyor belt moving toward the secondary air separator is provided between the bottom of the cylinder of the primary air separator and the air inlet duct of the secondary air separator.

[0013] Furthermore, a fourth conveyor belt is provided at the bottom of the first-stage drum screen and the second-stage drum screen. The first-stage drum screen has 8 meshes, and the second-stage drum screen has 2 meshes.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention filters the ground film through two drum screens, the first-level drum screen first filters out small particles of impurities attached to or carried by the ground film itself, the crusher breaks up the large impurities carried in the ground film and filters out the broken impurities through the second-level filter screen, and the impurity filtering effect is better; the remaining large or heavy impurities are separated by two air separators to improve the separation effect. The pretreatment of the ground film by the present invention does not require operations such as cleaning and drying to filter out impurities such as dust in the ground film. Compared with traditional cleaning, the filtration process not only saves water resources, but also automates the entire pretreatment process, reduces the participation of personnel, reduces labor and saves labor costs; in response to the problem that the crusher shaft is easily entangled with the ground film, the present invention uses an anti-entanglement mechanism to promptly clean up the ground film wrapped around the shaft, which can effectively prevent the technical problems caused by the ground film being wrapped around the shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a structural schematic diagram of the first-level drum screen of the present invention; Figure 3 It is a structural schematic diagram of the crusher of the present invention; Figure 4 It is a structural schematic diagram of the anti-winding mechanism of the present invention; Figure 5 It is a structural schematic diagram of the primary air separator of the present invention; Figure 6 It is a schematic diagram of the internal structure of the first-stage air separator of the present invention.

[0016] In the figure, 1. hydraulic nine-square grid; 2. primary drum screen; 21. support frame; 22. collecting cover; 23. drum screen; 24. dust removal cover; 3. crusher; 31. hopper; 32. machine base; 33. crushing knife; 34. rotating shaft; 35. anti-winding mechanism; 351. baffle; 352. convex plate; 36. cutting knife group; 361. cutting knife; 362. slide rail; 37. adjusting member; 371. screw rod; 372. adjusting plate; 373. gear; 374. handle; 4. secondary drum screen; 5. primary air separator; 51. base; 52. cylinder; 53. air inlet duct; 54. exhaust duct; 55. inverted cone block; 6. secondary air separator; 7. silo; 8. compression molding machine; 9. first chain plate; 10. first conveyor belt; 11. second chain plate; 12. second conveyor belt; 13. third conveyor belt. DETAILED DESCRIPTION

[0017] The following are specific embodiments of the present invention, and the technical scheme of the present invention is further described in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments. It should be noted that the structures such as the hydraulic nine-square grid 1, the silo 7 and the compression molding machine 8 in the present invention are all prior arts and will not be described in detail in the present invention.

[0018] like Figure 1-6 As shown, the present invention provides a pretreatment device for raw materials of a compression molding machine, comprising a hydraulic nine-square grid 1, a first-level drum screen 2, a crusher 3, a second-level drum screen 4, a first-level air separator 5, a second-level air separator 6, a silo 7 and a compression molding machine 8 connected in sequence, wherein the crusher 3 comprises a hopper 31, a machine base 32 located at the bottom of the hopper 31 and connected to the hopper 31, and two groups of crushing knife groups, wherein the crushing knife groups comprise a plurality of crushing knives 33 and a rotating shaft 34, wherein the crushing knives 33 are installed in the machine base 32 through the rotating shaft 34, and the machine base 32 is provided with There is an anti-winding mechanism 35, which includes a baffle 351. The baffle 351 is symmetrically arranged on both sides of the machine base 32, and the baffle 351 is inclined toward the direction of the crushing knife group. A plurality of convex plates 352 are provided on the baffle 351. The groove formed between two adjacent convex plates 352 allows the crushing knife 33 to pass through. The convex plate 352 is located between two adjacent crushing knives 33. A cutting knife group 36 is provided at the end of the convex plate 352. An adjusting member 37 for adjusting the extension and retraction of the cutting knife group 36 is provided on the baffle 351.

[0019] like Figure 3 and 4 As shown, the ground film falls into the machine base 32 through the hopper 31, and is broken up by two groups of crushing knife groups. A cutting knife group 36 is installed on one side of two adjacent crushing knives 33 on the rotating shaft 34. During the rotation of the rotating shaft 34, if there is ground film wrapped around the rotating shaft 34, the ground film wrapped around the rotating shaft 34 is cut in time by the anti-winding mechanism 35, which can effectively prevent the ground film from wrapping around the rotating shaft 34 and causing the rotating shaft 34 to be stuck, and the friction between the ground film and the equipment causes the temperature to rise, causing damage to the cutting tool, and other problems.

[0020] The cutting knife group 36 is provided with two groups, which are respectively arranged on the two end surfaces of the convex plate 352. The cutting knife group 36 includes a cutting knife 361 and a slide rail 362. The blade of the cutting knife 361 faces the direction of the rotating shaft 34. The cutting knife 361 is slidably installed in the slide rail 362. The adjustment member 37 drives the two groups of cutting knife groups 36 to move relative to or away from each other.

[0021] like Figure 4As shown, when the distance between two adjacent crushing knives 33 is adjusted as needed, the two groups of cutting knife groups 36 can be controlled by the adjusting member 37, so that the cutting knives 361 on the two side surfaces of the same convex plate 352 can slide relative to or away from each other. When the distance between two adjacent crushing knives 22 is shortened, the adjusting member 37 controls the cutting knife 361 to slide relative to each other, so that the cutting knife 361 contracts to cut the ground film wrapped on the rotating shaft 34 between the two adjacent crushing knives 33.

[0022] A sliding hole is provided on the side of the slide rail 363, and the adjusting member includes two groups, which respectively control the cutting knives 361 on the two groups of cutting knife groups 36. The adjusting member includes a screw rod 371 and an adjusting plate 372 matched with the number of the cutting knives 361. The adjusting plate 372 passes through the sliding hole and is connected to the cutting knives 361. The screw rod 371 is threadedly connected to the adjusting plate 372.

[0023] like Figure 4 As shown, by rotating the screw rod 371 to control the adjustment plate 372 to drive the cutting knife 361 to slide in the slide rail 362, the position of the cutting knife 361 in the slide rail 362 is changed, so that the cutting knife 361 contracts or expands, which is suitable for cutting ground films wound at multiple intervals.

[0024] One end of the two screw rods 371 passes through a side surface of the machine base 32 and is connected to mutually meshing gears 373 , and a handle 374 is provided on any one of the screw rods 371 .

[0025] like Figure 4 As shown, by rotating the handle 374, any gear 373 is driven to rotate, and the gear 373 drives the two screw rods 371 to rotate, thereby achieving relative or opposite movement of the adjustment plates 372.

[0026] The primary drum screen 2 and the secondary drum screen 3 both include a support frame 21, on which a collecting hood 22 is provided, in which a drum screen 23 is rotatably connected, and a dust removal hood 24 is provided on the top of the collecting hood 22, and the top of the dust removal hood 24 is connected to a dust collector (not shown) through an air outlet pipe.

[0027] like Figure 2 As shown, during the rolling screening of the ground film by the primary drum screen 2 and the secondary drum screen 3, the dust carried by the ground film itself will fall off on the one hand, and the dust will vibrate on the other hand. The vibrated dust will be collected by the dust hood 24 and the dust collector, and the screened small particles of impurities will leak out from the bottom of the drum screen 23, and large pieces of impurities and ground film will be discharged from the discharge port of the drum screen 23.

[0028] The primary air separator 5 and the secondary air separator 6 both include a base 51, a cylinder 52, an air inlet duct 53 and a centrifugal fan (not shown in the figure). The cylinder 52 is arranged on the base 51, the air inlet duct 53 is arranged on one side of the cylinder 52, and the outlet of the air inlet duct 53 is arranged upward. The centrifugal fan is connected to the top of the cylinder 52 through an exhaust duct 54.

[0029] like Figure 5 As shown, the centrifugal fan exhausts air, and the air inlet duct 53 screens the ground film containing large impurities after being filtered by the secondary drum screen 4. The air inlet duct 53 sucks the ground film and some impurities into the cylinder 52. The ground film is extracted from the cylinder 52 through the exhaust duct 54, and the heavier large impurities fall to the bottom of the cylinder 52, thereby realizing the separation of the ground film and the impurities again.

[0030] An inverted cone-shaped stopper 55 is connected to the upper part of the cylinder 52 via a support rod.

[0031] like Figure 1 As shown, the inverted cone block 55 breaks up the ground film so as to separate the ground film from the impurities. A process based on a pretreatment device for raw materials of a compression molding machine includes the following steps: ① Pre-break up the recycled plastic ground film mixture in a hydraulic nine-square grid 1, and after breaking up, transport it to the first drum screen 2 through the first chain plate 9 to filter out the sand or smaller stones and soil blocks mixed in the ground film; ② The mulch film screened in step ① is conveyed to the crusher 3 through the first conveyor belt 10 for crushing, and then conveyed to the secondary drum screen 4 through the second chain plate 11 after crushing, to screen out the large stones and soil blocks that are not screened out by the primary drum screen 2, and the large stones and soil blocks are crushed by the crusher 3 and then screened out by the secondary drum screen 4; ③ The material filtered by the secondary drum screen 4 in step ② is sequentially passed through the primary air separator 5 and the secondary air separator 6 to extract the ground film; ④ The ground film extracted by air selection in step ③ is transported to the silo 7 through the second conveyor belt 12 for storage.

[0032] like Figure 1As shown, the mulch recovered from the field is cut and broken up by a hydraulic nine-grid guillotine, and the broken up mulch is mixed with impurities such as straw, stones, and soil. The broken up mulch is transported to the primary drum screen 2 through the first chain plate 9. During the screening of the mulch in the primary drum screen 2 and the secondary drum screen 4, the dust adhering to the mulch will be shaken off. The dust attached to the mulch can be removed without washing. During the transportation of the mulch through the first chain plate 9, the dust or small granular impurities in the mulch will leak out from the first chain plate 9, and the mulch will roll in the primary drum screen 2, and the soil or smaller impurities in the mulch will be shaken off. The ground film after filtration is transported to the crusher 3 through the first conveyor belt 10 for crushing. In the process of crushing the ground film, large impurities in the ground film will be broken. The broken ground film enters the secondary drum screen 4 through the second chain plate 11. The impurities in the crushed ground film are filtered again in the secondary drum screen 4. Large pieces of stones or straw may be mixed in the ground film after filtration. The ground film is extracted by the first and second air separators 5 and 6, and the heavier stones or straw are left. The extracted ground film can be transported to the silo 7 for storage through the second conveyor belt 12, so that it can be transported to the compression molding machine 8 for extrusion molding later.

[0033] Step ③ A third conveyor belt 13 is provided between the bottom of the cylinder 52 of the primary air separator 5 and the air inlet duct 53 of the secondary air separator 6 and moves toward the secondary air separator.

[0034] like Figure 6 As shown, the secondary air separator 6 performs secondary air separation on the impurities such as straw and stones separated by the primary air separator 5, and air separates the ground film entangled by straw and pressed by large impurities such as stones, thereby improving the air separation effect.

[0035] The bottom of the primary drum screen 2 and the secondary drum screen 4 are both provided with a fourth conveyor belt. The primary drum screen 2 has 8 meshes, and the secondary drum screen 4 has 2 meshes.

[0036] like Figure 1 As shown, the impurities filtered out by the primary drum screen 2 and the secondary drum screen 4 are collected and recycled by the fourth conveyor belt and can be returned to the field. The primary drum screen 2 first filters the small particles of impurities in the ground film, mainly screening out the small particles of impurities attached to or carried on the ground film, and the secondary drum screen 4 is used to filter the large particles of impurities.

[0037] Principle of use: For the recycled plastic mulch to be used as the raw material for making pallets, its pretreatment includes the following steps: ① The recycled plastic mulch is placed in the hydraulic nine-square grid 1 for pre-dispersion. After being dispersed, the mulch is transported to the first-level drum screen 2 through the first chain plate 9, and the mulch is preliminarily filtered to filter out the sand or smaller stones, soil blocks and other impurities mixed in the mulch. During the rolling process of the dust and other small particles attached to the mulch in the first-level drum screen 2, the dust and other small particles are separated from the mulch, and a part of them will be screened out in the drum screen 23. The screened dust and other small particles fall onto the fourth conveyor belt at the bottom, and are transported to a collection mechanism for recycling through the fourth conveyor belt, so as to facilitate the return to the field later. The other part will float up, and the floating dust will be collected under the action of the dust removal hood 24 and the dust collector. The collected dust can also be used for returning to the field; ② The ground film screened out in step ① is conveyed to the crusher 3 through the first conveyor belt 10 for crushing. When the ground film is crushed in the crusher 3, large pieces of soil, stones, straw and other impurities mixed in the ground film are also crushed under the action of the crusher 3. The crushed ground film and impurities are then conveyed to the secondary drum screen 4 through the second chain plate 11. During the conveying process of the second chain plate 11, the second chain plate 11 will also screen out a part of the impurities that are broken into small particles. The crushed ground film and impurities enter the secondary drum screen 4 to screen out large pieces of stones and soil that are not screened out by the first drum screen 2. The large pieces of stones and soil are crushed by the crusher 3 and then screened out by the secondary drum screen 4. The screened out impurities will be collected by the fourth conveyor belt for returning to the field, and the agitated dust will be collected by the dust hood 24 and the dust collector and can also be used for returning to the field; ③ The material filtered by the secondary drum screen 4 in step ② may contain impurities such as large pieces of stones and straw that have not been broken. These impurities and ground film are sucked into the cylinder 52 through the air inlet duct 53, and the lighter ground film is sucked out through the exhaust duct 54 in the cylinder 52. The sucked-out ground film is transported to the silo 7 for storage through the second conveyor belt 12. Impurities such as stones and straws with heavier materials fall to the bottom of the cylinder 52. The impurities at the bottom of the cylinder 52 of the primary drum screen 4 are then transported to the entrance of the air inlet duct 53 of the secondary air separator 6 through the third conveyor belt 13. The secondary air separator 6 further air-selects it to extract the ground film from the impurities, so that the heavier impurities remain at the bottom of the cylinder 52 of the secondary air separator 6, and the ground film and impurities are separated again. The ground film separated by the secondary air separator 6 will also be transported to the silo 7 for storage through the second conveyor belt 12. When making a pallet, the stored ground film can be transported to the compression molding machine 8 for heating and compression molding.

[0038] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A pretreatment device for raw materials of a compression molding machine, characterized in that: The invention comprises a hydraulic nine-square grid (1), a first-stage drum screen (2), a crusher (3), a second-stage drum screen (4), a first-stage air separator (5), a second-stage air separator (6), a silo (7) and a compression molding machine (8) which are connected in sequence. The crusher (3) comprises a hopper (31), a machine base (32) located at the bottom of the hopper (31) and connected to the hopper (31), and two sets of crushing knife groups. The crushing knife groups comprise a plurality of crushing knives (33) and a rotating shaft (34). The crushing knives (33) are installed in the machine base (32) via the rotating shaft (34). The machine base ( An anti-winding mechanism (35) is provided in the machine base (32), the anti-winding mechanism (35) comprising baffles (351), the baffles (351) are symmetrically arranged on both sides of the machine base (32), and the baffles (351) are inclined in the direction of the crushing knife group, a plurality of convex plates (352) are provided on the baffles (351), the convex plates (352) are located between two adjacent crushing knives (33), a cutting knife group (36) is provided at the end of the convex plates (352), and an adjusting member (37) for adjusting the extension and retraction of the cutting knife group (36) is provided on the baffles (351).

2. A pretreatment device for raw materials of a compression molding machine according to claim 1, characterized in that: The cutting knife group (36) is provided with two groups, which are respectively arranged on the two end surfaces of the convex plate (352). The cutting knife group (36) comprises a cutting knife (361) and a slide rail (362). The cutting edge of the cutting knife (361) faces the direction of the rotating shaft (34). The cutting knife (361) is slidably installed in the slide rail (362). The adjustment member (37) drives the two cutting knife groups (36) to move relative to or away from each other.

3. A pretreatment device for raw materials of a compression molding machine according to claim 2, characterized in that: A sliding hole is provided on the side of the slide rail (363), and the adjusting member comprises two groups, which respectively control the cutting knives (361) on the two groups of cutting knife groups (36). The adjusting member comprises a screw rod (371) and an adjusting plate (372) whose number matches the number of the cutting knives (361). The adjusting plate (372) passes through the sliding hole and is connected to the cutting knives (361), and the screw rod (371) is threadedly connected to the adjusting plate (372).

4. The pretreatment equipment for raw materials of a compression molding machine according to claim 3, characterized in that: One end of the two screw rods (371) passes through a side surface of the machine base (32) and is connected to mutually meshing gears (373), and a handle (374) is provided at the end of any one of the screw rods (371).

5. The pretreatment equipment for raw materials of a compression molding machine according to claim 1, characterized in that: The first-stage drum screen (2) and the second-stage drum screen (3) both comprise a support frame (21), a collecting cover (22) being provided on the support frame (21), the drum screen (23) being rotatably connected inside the collecting cover (22), and a dust removal cover (24) being provided on the top of the collecting cover (22).

6. The pretreatment equipment for raw materials of a compression molding machine according to claim 1, characterized in that: The first-stage air separator (5) and the second-stage air separator (6) both comprise a base (51), a cylinder (52), an air inlet duct (53) and a centrifugal fan; the cylinder (52) is arranged on the base (51); the air inlet duct (53) is arranged on one side of the cylinder (52); and the centrifugal fan is connected to the top of the cylinder (52) via an air exhaust duct (54).

7. A pretreatment device for raw materials of a compression molding machine according to claim 6, characterized in that: An inverted cone-shaped stopper (55) is connected to the upper portion of the cylinder (52) via a support rod.

8. The pretreatment process of the pretreatment equipment for the raw materials of the compression molding machine according to claims 1-7 comprises the following steps: ① placing the recovered plastic mulch mixture in a hydraulic nine-square grid (1) for pre-dispersion, and after the dispersion, conveying it to the primary drum screen (2) through the first chain plate (9) to filter out the sand or smaller stones and soil blocks mixed in the mulch; ② The ground film screened in step ① is conveyed to a crusher (3) through a first conveyor belt (10) for crushing, and then conveyed to a secondary drum screen (4) through a second chain plate (11) after crushing, to screen out large rocks and soil blocks that are not screened out by the primary drum screen (2). The large rocks and soil blocks are crushed by the crusher (3) and then screened out by the secondary drum screen (4); ③ The material filtered by the secondary drum screen (4) in step ② is passed through the primary air separator (5) and the secondary air separator (6) in sequence to extract the ground film; ④ The ground film extracted by air selection in step ③ is transported to the silo (7) through the second conveyor belt (12) for storage, so as to be heated and extruded by the compression molding machine (8).

9. A pretreatment process for raw materials of a compression molding machine according to claim 8, characterized in that: In step ③, a third conveyor belt (13) is provided between the bottom of the cylinder (52) of the primary air separator (5) and the air inlet duct (53) of the secondary air separator (6), and moves in the direction of the secondary air separator (6).

10. A pretreatment process for raw materials of a compression molding machine according to claim 8, characterized in that: The first-stage drum screen (2) has 8 meshes, the second-stage drum screen (4) has 2 meshes, and a fourth conveyor belt is provided at the bottom of each of the first-stage drum screen (2) and the second-stage drum screen (4).

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