Metal scrap cake pressing process with high deoiling and dehydrating rate

Abstract

The invention relates to the technical field of metal scrap recovery treatment, in particular to a metal scrap cake pressing process with high deoiling and dewatering rate, which comprises the following steps: carrying out shredding and water filtering pretreatment on conveyed metal scraps to obtain metal scraps; detecting the weight of the metal chips, and weighing the metal chips meeting the preset weight; gathering and pushing: gathering and arranging the metal chippings meeting the preset weight, and pushing the metal chippings to an extrusion cavity by a first preset pushing force; according to preset extrusion conditions, the metal scraps in the extrusion cavity are subjected to bidirectional extrusion forming, and oil and water are removed while a metal cake is formed; and according to second preset thrust, the formed metal cake and the removed oil liquid and water are pushed out of the extrusion cavity, and discharging and oil liquid and water collection are achieved. According to the invention, the problems of dispersed equipment, high energy consumption, low deoiling and dewatering rate and the like in the prior art can be solved, and the cost control and environmental protection requirements in a large-scale recovery scene are difficult to meet.

Description

Technical Field

[0001] The invention relates to the technical field of metal waste recycling and processing, in particular to a metal waste cake pressing process with high deoiling and dehydration rates. Background Art

[0002] With the rapid development of industries like automotive manufacturing, electronics and communications, machining, and construction, the consumption of metal materials has been rising annually. Approximately 30%-40% of the resulting metal scrap is contaminated with cutting fluids, lubricants, and other oils (e.g., oily steel shavings from automobile dismantling and oily aluminum shavings from machining). Statistics show that my country generates tens of millions of tons of scrap metals from steel, aluminum, and copper alone annually. Without efficient deoiling and dehydration, this waste not only pollutes the workshop environment due to the evaporation of oil, but also generates large amounts of harmful gases (such as benzene and soot particles) during the smelting process. Furthermore, residual oil reduces the purity of the molten metal, impacting the quality of the recycled metal.

[0003] In the current metal scrap recycling industry, the traditional unidirectional extrusion cake pressing process faces significant technical bottlenecks in deoiling and dehydration. First, the waste pretreatment process lacks a systematic design. This makes it difficult to effectively separate the oily substances and efficiently dehydrate metal scraps mixed with oil and water (such as lathe chips containing cutting fluid and oily aluminum profile scraps). This results in cake oil contents often exceeding 8% and moisture contents exceeding 15%. The concentration of harmful gases produced by the volatilization of oil at high temperatures during smelting exceeds national standards by 3-5 times, and the heat consumed by oil combustion increases smelting energy consumption by 20-30%. Second, insufficient equipment integration leads to low deoiling and dehydration efficiency. Loading, shredding, weighing, and extrusion processes are often performed independently, lacking a centralized oil collection system. A single production line for oily waste only achieves a deoiling rate of 30-40%, occupies over 200 square meters, and requires frequent manual cleaning, resulting in a production efficiency of only 3-5 tons per hour. Third, the unidirectional extrusion force is uneven, and the oil inside the metal waste is difficult to be completely discharged. The residual oil rate inside the pressed cake is more than 20%. The oil leakage during transportation not only pollutes the environment, but also increases the rust rate of the metal cake by 5-8 times. The metal recovery rate is only 85%-90%.

[0004] Driven by the "dual carbon" goals and resource recycling policies, the deoiling and dehydration of oily metal scrap has become a mandatory industry requirement. Existing processes, due to issues such as dispersed equipment, high energy consumption, and low deoiling and dehydration rates, struggle to meet the green production demands of large-scale recycling. There is an urgent need to develop a highly integrated metal scrap cake pressing process with efficient deoiling and dehydration capabilities. Summary of the Invention

[0005] The purpose of the present invention is to propose a metal waste cake pressing process with a high deoiling and dehydration rate, which can solve the problems of the existing process such as scattered equipment, high energy consumption, and low deoiling and dehydration rate, and is difficult to meet the cost control and environmental protection requirements in large-scale recycling scenarios.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A metal scrap cake pressing process with high deoiling and dehydration rate comprises the following steps:

[0008] Shredding and filtering: Shredding and filtering the delivered metal waste to obtain metal scraps;

[0009] Weighing and feeding: Check the weight of metal scraps and weigh the metal scraps that meet the preset weight;

[0010] Gathering and pushing: Gather and sort the metal debris that meets the preset weight, and push the metal debris into the extrusion chamber with a first preset thrust;

[0011] Bidirectional extrusion molding: According to the preset extrusion conditions, the metal chips in the extrusion cavity are subjected to bidirectional extrusion molding to form metal cakes while removing oil and water;

[0012] Discharging and collecting oil and water: According to the second preset thrust, the formed metal cake, the released oil and water are pushed out of the extrusion cavity, and the discharging, oil and water collection are achieved.

[0013] Preferably, in the shredding and water filtering steps, the conveying speed of the metal waste is 0.5-1 m / s.

[0014] Preferably, in the shredding and water filtering steps, the particle size of the shredded metal waste is in the range of 10-20 cm.

[0015] Preferably, in the weighing and feeding steps, the preset weight is 40kg-60kg, and the error range of the weight detection is ±10%.

[0016] Preferably, in the material gathering and pushing steps, the first preset thrust is 10-15 MPa.

[0017] Preferably, in the bidirectional extrusion molding step, the preset extrusion conditions include an extrusion pressure of 20-35 MPa, an extrusion speed of 0.2-0.5 m / s and an extrusion time of 20-30 s.

[0018] Preferably, in the discharging and oil-water collecting steps, the second preset thrust is 10-15 MPa.

[0019] One of the above technical solutions has the following beneficial effects: the step design is scientific and reasonable, the operation process is clear and simple, and there is no need for complicated operating skills and a large amount of manual intervention. The equipment required for this process is highly integrated. Compared with the scattered independent equipment of the traditional process, the types and quantity of equipment are reduced, and the loss of raw materials is reduced. At the same time, the entire process does not involve the use of harmful chemicals and does not produce substances that pollute the environment, which meets environmental protection requirements. Through the close coordination of steps such as shredding and water filtration, weighing and feeding, gathering and pushing, two-way extrusion molding, and discharging and oil and water collection, various types of metal scraps can be efficiently processed, and high-density cakes and high dehydration rates of metal scraps can be achieved, which significantly improves the metal recovery rate, effectively realizes the recycling of metal resources, and achieves ideal waste treatment and resource recovery effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic flow diagram of the process of the present invention;

[0021] Figure 2 This is a schematic top view of the structure of the process of the present invention applied to a production line;

[0022] Figure 3 This is a schematic side view of the structure of the process of the present invention applied to a production line;

[0023] Figure 4 It is a schematic diagram of the structure of the loading and conveying device and the feeding and conveying device in the production line when the process of the present invention is applied;

[0024] Figure 5 This is a schematic diagram of the structure of a double-shaft shredding device in a production line when the process of the present invention is applied;

[0025] Figure 6 This is a schematic diagram of the structure of a water filtration device in a production line when the process of the present invention is applied;

[0026] Figure 7 This is a schematic diagram of the structure of the process of the present invention applied to the conveying weighing unit in the production line;

[0027] Figure 8 It is a schematic diagram of the structure of the material gathering and pushing unit, the bidirectional extrusion molding unit and the discharging unit in the production line of the process of the present invention;

[0028] Figure 9 yes Figure 8 Schematic top view of

[0029] Figure 10 yes Figure 9 Schematic diagram of the cross section at AA in the middle;

[0030] Figure 11 yes Figure 9 Schematic diagram of the cross section at the middle BB;

[0031] In the drawings: pre-processing unit 1, feeding and conveying device 11, conveyor belt 111, conveying motor 112, conveying roller 113, baffle 114, double-shaft shredder device 12, box 121, feeding port 1211, feeding port 1212, double-shaft shredder assembly 122, shredder drive motor 1221, main shaft 1222, blade 1223, shredder frame 123, water filtering device 13, hopper 131, water filtering bracket 132, screw conveying assembly 133, screw barrel 1331, screw 1332, screw drive motor 1333, feeding port 1334, water filtering port 1335, feeding and conveying device 14;

[0032] Conveying weighing unit 2, weighing bracket 21, weighing plate 22, weighing conveyor belt 23, weighing conveying motor 24, weighing conveying roller 25, baffle 26;

[0033] Material gathering and pushing unit 3, material gathering frame 31, material gathering port 311, material pushing port 312, material gathering device 32, material gathering cylinder 321, material gathering telescopic rod 322, material gathering plate 323, material pushing device 33, material pushing cylinder 331, material pushing telescopic rod 332, material pushing plate 333, support frame 34;

[0034] Bidirectional extrusion molding unit 4, extrusion seat 41, extrusion chamber 411, feed port 412, extrusion port 413, discharge port 414, hydraulic extrusion device 42, hydraulic cylinder 421, hydraulic telescopic rod 422, extrusion head 423;

[0035] Discharging unit 5, discharging slide 51, water collecting base 52;

[0036] Central control unit 6. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0040] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] like Figure 1 As shown, a metal scrap cake pressing process with high deoiling and dehydration rate includes the following steps:

[0042] Shredding and filtering: Shredding and filtering the delivered metal waste to obtain metal scraps;

[0043] Weighing and feeding: Check the weight of metal scraps and weigh the metal scraps that meet the preset weight;

[0044] Gathering and pushing: Gather and sort the metal debris that meets the preset weight, and push the metal debris into the extrusion chamber with a first preset thrust;

[0045] Bidirectional extrusion molding: According to the preset extrusion conditions, the metal chips in the extrusion cavity are subjected to bidirectional extrusion molding to form metal cakes while removing oil and water;

[0046] Discharging and collecting oil and water: According to the second preset thrust, the formed metal cake and the released oil and water are pushed out of the extrusion cavity, and the discharging, oil and water collection are achieved.

[0047] like Figure 1 As shown, the bidirectional extrusion type metal scrap cake pressing process realizes efficient metal scrap cake processing through a systematic process. In order to more clearly describe the process of this process, a preferred structural embodiment is applied: a bidirectional extrusion metal scrap automatic cake pressing production line, including a pretreatment unit 1, a conveying and weighing unit 2, a material gathering and pushing unit 3, a bidirectional extrusion molding unit 4 and a discharging unit 5 connected in sequence, as shown in FIG. Figure 2 As shown;

[0048] The pre-treatment unit 1 is used to shred and filter the transported metal waste, and then send the pre-treated metal waste to the transport weighing unit 2;

[0049] The conveying weighing unit 2 is used to detect the weight of the pre-treated metal scraps, and to deliver the metal scraps that meet the preset weight to the bidirectional extrusion molding unit 4 through the material gathering and pushing unit 3;

[0050] The gathering and pushing unit 3 is used to gather and sort the metal scraps that meet the preset weight, and push them into the extrusion cavity 411 of the bidirectional extrusion molding unit 4 with a first preset thrust;

[0051] The bidirectional extrusion unit 4 is used to bidirectionally extrude the metal scrap in the extrusion chamber 411 according to preset extrusion conditions to form a metal cake; and to push the formed metal cake, the released oil and water out of the extrusion chamber 411 according to a second preset thrust.

[0052] The discharging unit 5 is used to collect the metal cakes, oil and water pushed out from the extrusion cavity 411;

[0053] The pretreatment unit 1, the conveying and weighing unit 2, the material gathering and pushing unit 3 and the bidirectional extrusion molding unit 4 are all electrically connected to the central control unit 6, and the central control unit 6 is used to control the pretreatment unit 1, the conveying and weighing unit 2, the material gathering and pushing unit 3 and the bidirectional extrusion molding unit 4 to operate according to this process.

[0054] In summary, the bidirectional extrusion type metal waste cake pressing process has scientific and reasonable step design, clear and simple operation process, and does not require complicated operation skills and a lot of manual intervention. The equipment required for this process is highly integrated. Compared with the scattered independent equipment of the traditional process, the types and quantity of equipment are reduced, and the loss of raw materials is reduced. At the same time, through the close coordination of the steps of shredding and water filtration, weighing and feeding, gathering and pushing, bidirectional extrusion molding, and discharging and oil and water collection, various types of metal waste can be efficiently processed, and high-density pressed cakes of metal waste can be achieved. The oil and water content of the high-density pressed cakes can be less than 3%, which significantly improves the metal recovery rate, effectively realizes the recycling of metal resources, and achieves ideal waste treatment and resource recovery effects.

[0055] To further illustrate, in the shredding and water filtering steps, the conveying speed of the metal waste is 0.5-1 m / s.

[0056] To further illustrate, in the shredding and water filtering steps, the particle size of the shredded metal waste is in the range of 10-20 cm.

[0057] Specifically, the pre-treatment unit 1 includes a loading and conveying device 11, a double-shaft shredding device 12, a water filtering device 13 and a feeding and conveying device 14 connected in sequence;

[0058] The loading conveyor 11 and the feeding conveyor 14 are both arranged at an angle, and the double-shaft shredder 12 is installed at the higher end of the loading conveyor 11, and the water filter 13 is installed at the lower end of the feeding conveyor 14. The water filter 13 is located at the feed port 1212 of the double-shaft shredder 12;

[0059] The loading conveying device 11 includes a conveyor belt 111, a conveying motor 112 and a plurality of conveying rollers 113. The conveyor belt 111 is wound around the roller bodies of the plurality of conveying rollers 113. The conveying motor 112 is connected to one of the conveying rollers 113. The conveyor belt 111 is provided with a plurality of equally spaced baffles 114, and the baffles 114 protrude from the conveyor belt 111.

[0060] The double-shaft shredder device 12 includes a box body 121, a double-shaft shredder assembly 122 and a shredder frame 123 for supporting the box body 121 and the double-shaft shredder assembly 122, the double-shaft shredder assembly 122 is symmetrically arranged on both sides of the box body 121, the double-shaft shredder assembly 122 includes a shredding drive motor 1221 and a main shaft 1222, the two main shafts 1222 are arranged in parallel in the box body 121, the two main shafts 1222 are respectively connected to the two shredding drive motors 1221, and a plurality of blades 1223 are respectively sleeved and fixed on the shaft bodies of the two main shafts 1222, the top end of the box body 121 is provided with a loading port 1211, the loading port 1211 is provided with a higher end of the loading and conveying device 11, the bottom end of the box body 121 is provided with a feeding port 1212, and the water filtering device 13 is provided at the feeding port 1212;

[0061] The water filtering device 13 includes a hopper 131, a screw conveying assembly 133 and a water filtering bracket 132 for supporting the hopper 131 and the screw conveying assembly 133. The screw conveying assembly 133 includes a screw barrel 1331, a screw 1332 and a screw drive motor 1333. The upper opening of the hopper 131 is located below the feed port 1212. The lower opening of the hopper 131 is connected to the screw barrel 1331. The screw 1332 is installed in the horizontal direction of the screw barrel 1331. Inside the screw barrel 1331, the screw drive motor 1333 is installed through one end of the screw barrel 1331 in the horizontal direction, and the screw drive motor 1333 is connected to one end of the screw 1332. The other end of the screw barrel 1331 in the horizontal direction is provided with a feed port 1334, and the feed port 1334 is provided with the lower end of the feeding and conveying device 14. The bottom end of the screw barrel 1331 in the horizontal direction is provided with a water filter port 1335, and the water filter port 1335 is provided with a filter screen.

[0062] The feeding conveying device 14 and the loading conveying device 11 have the same structure.

[0063] like Figure 3-6 As shown, in the metal scrap pre-processing process, the loading and conveying device 11 is first started, and the conveying motor 112 drives the conveying roller 113 to rotate, thereby driving the conveyor belt 111 to operate at a conveying speed of 0.5-1m / s. The evenly spaced baffles 114 on the conveyor belt 111 have both anti-slip and preliminary weighing functions, which not only ensure the stable loading of metal scraps and prevent them from falling and piling up during transportation, but also can perform preliminary weighing of the metal scraps. Since the baffles 114 are evenly spaced, when the conveyor belt 111 is running, relatively fixed spatial areas are formed between adjacent baffles 114. As the metal scraps are continuously conveyed, the amount of metal scrap falling into each area is roughly the same, thereby achieving a preliminary weighing effect, making the amount of metal scrap entering the dual-axis shredder 12 relatively uniform, which helps the dual-axis shredder 12 operate stably and efficiently.

[0064] After the metal scrap enters the housing 121 through the feed port 1211, the shredder drive motors 1221 on either side of the housing 121 respectively drive the two main shafts 1222 to rotate, causing the multiple blades 1223 mounted on the shafts 1222 to rotate at high speed. The dual-axis, counter-rotating blades 1223 design can more quickly and effectively crush hard metal scrap than a single-axis shredder, significantly improving crushing efficiency. The crushed metal scrap has a particle size range of 10-20 cm, allowing the oil and water contained in the scrap to be separated from the solid material while ensuring a more even distribution of the material in the extrusion chamber, avoiding stress concentration caused by large particles and improving the density stability of the pressed cake.

[0065] The crushed material is discharged from the feed port 1212 at the bottom of the housing 121 and directly falls into the hopper 131 of the water filter 13. After the hopper 131 receives the material, the screw drive motor 1333 is activated, driving the screw 1332 to rotate within the barrel 1331. The rotation of the screw 1332 pushes the material horizontally along the barrel 1331. During this process, the oil and water in the material are discharged through the water filter port 1335 at the bottom of the barrel 1331. The filter screen at the water filter port 1335 intercepts the material and prevents it from flowing out with the water. The deoiled and dehydrated material is finally discharged from the feed port 1334 at the other end of the barrel 1331 and is received by the feeding and conveying device 14.

[0066] The feed conveyor 14 operates in the same manner as the loading conveyor 11, transporting the pretreated scrap metal to the delivery weighing unit 2 at a speed of 0.5-1 m / s, completing the entire pretreatment process. It is worth noting that the initial weighing function of the stop bar 114 on the feed conveyor 14 reduces weight fluctuations in the material delivered to the delivery weighing unit 2, alleviating the operating pressure on the weighing unit and improving weighing accuracy and efficiency.

[0067] To further illustrate, in the weighing and feeding steps, the preset weight is 40kg-60kg, and the error range of the weight detection is ±10%.

[0068] Specifically, the conveying weighing unit 2 includes a weighing conveying device and a weighing bracket 21 for supporting the weighing conveying device, and the weighing conveying device is equipped with a weight sensor;

[0069] The weighing and conveying device includes a weighing plate 22, a weighing conveyor belt 23, a weighing conveying motor 24 and multiple weighing conveying rollers 25. The weighing conveyor belt 23 is wound around the roller body of the multiple weighing conveying rollers 25. The weighing conveying motor 24 is connected to one of the weighing conveying rollers 25. Baffles 26 are installed on both sides of the weighing conveyor belt 23. The outer periphery of the weighing plate 22 is fixedly installed with the baffle 26. The weighing plate 22 is suspended above the weighing conveyor belt 23 through the baffle 26. The weighing plate 22 is located below the higher end of the feeding and conveying device 14.

[0070] When the feeding and conveying device 14 of the pre-treatment unit 1 conveys the shredded and filtered metal scraps to the higher end, the metal scraps fall to the conveying and weighing unit 2 below by gravity.

[0071] In the conveying weighing unit 2, the weighing fence 22 is fixedly connected to the baffle 26 and is suspended just above the weighing conveyor belt 23 to accurately receive the metal scrap falling from the feeding conveying device 14. The weight sensor installed on the weighing conveying device monitors the weight of the scrap in real time, converts the weight data into an electrical signal and transmits it to the central control unit 6. After receiving the data, the central control unit 6 will compare it with the preset weight parameters. If the current scrap weight does not reach the preset weight of 10-20kg with an error of ±10%, the central control unit 6 controls the pretreatment unit 1 to continue conveying the metal scrap, while the weighing conveying device continues to stop running; when the weight reaches the preset weight of 10-20kg with an error of ±10%, the central control unit 6 issues a command to stop the action of the pretreatment unit 1 and start the weighing conveying device at the same time. The ±10% weight error control ensures that the weight of each batch of pressed cakes is consistent, improves the accuracy of the ingredients in the downstream smelting link, and increases the metal recovery rate by 2%-3%.

[0072] The weighing conveyor device uses a weighing conveyor motor 24 to drive the connected weighing conveyor rollers 25 to rotate, which in turn drives the weighing conveyor belt 23 wrapped around the rollers 25 at a conveying speed of 0.5-1m / s. As the weighing conveyor belt 23 rotates, the metal scrap is smoothly conveyed to the bidirectional extrusion molding unit 4.

[0073] To further explain, in the material gathering and pushing steps, the first preset thrust is 10-15 MPa.

[0074] Specifically, the material gathering and pushing unit 3 includes a material gathering frame 31, a material gathering device 32, a material pushing device 33 and a support frame 34 for supporting the material gathering frame 31, the material gathering device 32 and the material pushing device 33;

[0075] The material collecting frame 31 is located below the discharge end of the conveying weighing unit 2, and the two opposite surfaces of the material collecting frame 31 are respectively provided with a material collecting port 311 and a material pushing port 312;

[0076] The bidirectional extrusion molding unit 4 includes an extrusion seat 41 , an extrusion cavity 411 is formed inside the extrusion seat 41 , and a feed port 412 is provided in the extrusion cavity 411 ;

[0077] The material collection port 311 is arranged opposite to the material feeding port 412;

[0078] The material gathering device 32 is installed at the material gathering port 311 and is used to gather and sort the metal scraps that fall into the material gathering frame 31;

[0079] The pushing device 33 is installed at the pushing port 312 , and is used to push the metal scraps falling into the gathering frame 31 into the extrusion cavity 411 through the gathering port 311 and the feed port 412 .

[0080] To further explain, in the material gathering and pushing steps, the first preset thrust is 10-15 MPa.

[0081] The material gathering device 32 includes a material gathering cylinder 321, a material gathering telescopic rod 322 and a material gathering plate 323;

[0082] One end of the material gathering telescopic rod 322 is connected to the material gathering cylinder 321, and the other end of the material gathering telescopic rod 322 is hinged to the material gathering plate 323;

[0083] The material gathering plate 323 is hinged to the material gathering frame 31 , and the material gathering cylinder 321 drives the material gathering plate 323 through the material gathering telescopic rod 322 to cover the upper opening of the material gathering frame 31 .

[0084] Since the metal scraps falling from the conveying weighing unit 3 into the gathering frame 31 will accumulate in a hill shape, the highest position may be higher than the height of the gathering frame 31. At this time, the pushing device 32 cannot push all the metal scraps from the gathering port into the extrusion chamber 411. It is easy for the metal scraps that are higher than the gathering frame 31 to fall out of the gathering frame due to obstruction. This not only wastes metal scraps, but also makes the amount of metal scraps pushed into the extrusion chamber 411 uncontrollable, resulting in the inability to guarantee the subsequent extrusion effect. Therefore, a gathering device 32 is provided above the gathering frame 31, which can be flipped over as needed to discharge the metal scraps in the gathering frame 31 downward, so that the height of the metal scraps in the gathering frame 31 will not exceed the height of the gathering frame 31, and can be completely pushed into the extrusion chamber 411 by the pushing device 33, thereby ensuring the subsequent extrusion effect.

[0085] The pushing device 33 includes a pushing cylinder 331, a pushing telescopic rod 332 and a pushing plate 333;

[0086] One end of the pusher telescopic rod 332 is connected to the pusher cylinder 331 , and the other end of the pusher telescopic rod 332 is connected to the pusher plate 333 .

[0087] like Figure 8-9 As shown, after the conveying weighing unit 2 completes the weighing of the metal scrap, the scrap that reaches the preset weight is transported to the discharge end through the weighing conveyor belt 23, and falls into the collection frame 31 below by gravity. The collection frame 31 accurately receives the metal scrap that falls from the weighing and conveying device.

[0088] like Figure 10 As shown, before the pushing device 33 starts working, the gathering cylinder 321 drives the gathering telescopic rod 322 to contract, driving the gathering plate 323 to flip upward, so that the gathering frame 31 is in an open state to receive materials.

[0089] When the scrap metal has completely fallen into the collection frame 31, one side of the push port 312 is blocked by the push plate 333. The collection cylinder 321 drives the telescopic rod 322 in the opposite direction to extend, causing the collection plate 323 to flip downward about the hinge point, pushing the over-accumulated scrap metal downward into the collection frame 31. The push cylinder 331 is activated, pushing the telescopic rod 332 to extend, driving the push plate 333 forward to apply thrust to the scrap metal, forcing it toward the collection port 311. As the push plate 333 pushes the scrap metal forward, the downwardly tilted collection plate 323 gradually pulls the scrap metal that is higher than the edge of the collection frame 31 and piled up in a disorderly manner toward the collection port 311. Through the coordinated action of the gathering plate 323 and the pushing plate 333, not only is the waste material effectively prevented from overflowing the gathering frame 31 during the pushing process, but the gaps inside the waste material are further compressed, making the material distribution more dense and even, and able to completely enter the extrusion cavity 411, creating good conditions for subsequent extrusion molding.

[0090] Subsequently, the push plate 333 continuously exerts force, with a first preset thrust of 10-15 MPa, to push the sorted metal scrap from the push port 312 through the gathering port 311, along the direction corresponding to the loading port 1211 of the extrusion cavity 411, and accurately into the extrusion cavity 411 inside the extrusion seat 41.

[0091] Specifically, the shape of the push plate 333 facing the extrusion chamber 411 needs to be set according to the specific shape of the extrusion chamber 411. Therefore, after the push plate 333 pushes the metal scrap into the extrusion chamber 411, the push plate 333 will not move during the extrusion molding process. The push plate 333 now acts as the molding wall of the extrusion chamber 411 at the feed port 412; for example, when the extrusion chamber 411 is cylindrical, the shape of the push plate 333 facing the extrusion chamber 411 is an arc surface.

[0092] To further illustrate, in the bidirectional extrusion molding step, the preset extrusion conditions include an extrusion pressure of 20-35 MPa, an extrusion speed of 0.2-0.5 m / s and an extrusion time of 20-30 s.

[0093] Specifically, the bidirectional extrusion molding unit 4 includes a hydraulic extrusion device 42 symmetrically installed on both sides of the extrusion seat 41;

[0094] The extrusion cavity 411 is further provided with an extrusion port 413 and a discharge port 414 , and the extrusion port 413 and the discharge port 414 are symmetrically arranged on both sides of the extrusion cavity 411 ;

[0095] The hydraulic extrusion device 42 includes a hydraulic cylinder 421, a hydraulic telescopic rod 422, and an extrusion head 423. One end of the hydraulic telescopic rod 422 is connected to the piston in the hydraulic cylinder 421, and the other end of the hydraulic telescopic rod 422 is connected to the extrusion head 423. The expansion and contraction directions of the two extrusion heads 423 are collinear with the axial direction of the extrusion chamber 411, and the cross-section of the extrusion head 423 is the same as the cross-section of the extrusion chamber 411.

[0096] The two hydraulic cylinders 421 are used to respectively drive the extrusion heads 423 connected thereto to move along the axial direction of the extrusion chamber 411 .

[0097] like Figure 11As shown, after the metal scrap enters the extrusion chamber 411, the bidirectional extrusion molding unit 4 plays a core role. The extrusion heads 423 on both sides of the extrusion chamber 411 are simultaneously started under the drive of the hydraulic cylinder 421, and apply a pressure of 20-35MPa (30-50MPa for steel scrap and 20-30MPa for aluminum / copper scrap) to the metal scrap in the extrusion chamber 411 from two opposite directions at a speed of 0.5-1mm / s, and squeeze them in opposite directions for 10-30 seconds. Under the continuous action of bidirectional pressure, the oil and water inside the metal scrap are further squeezed out, and the metal scrap is compressed to form a high-density metal cake with a density of 5-6g / cm 3 , with an oil and water content of less than 3%. It should be noted that bidirectional extrusion increases cake density by 20%-30% compared to unidirectional extrusion, reduces volume by 30% for the same weight, and reduces transportation costs by over 40%. The high oil and water removal rate of over 97% significantly reduces energy consumption in the smelting process. It is estimated that every ton of scrap processed can save 15%-20% in smelting energy.

[0098] To further illustrate, in the discharging and oil-water collection steps, the second preset thrust is 10-15 MPa.

[0099] Specifically, the discharging unit 5 includes a discharging slide 51 and a water collecting base 52;

[0100] The discharging slide 51 is arranged at an angle, and the higher end of the discharging slide 51 is located below the discharging port 414;

[0101] The discharging slide 51 is provided with a plurality of water filtering holes, and the water collecting base 52 is located below the bidirectional extrusion molding unit 4 .

[0102] like Figure 11 As shown, when the extrusion operation is completed, the hydraulic telescopic rod 422 located at the discharge port 414 first contracts until it is completely removed from the extrusion chamber 411, exposing the discharge port 414 that was originally blocked by the hydraulic telescopic rod 422. At this time, the hydraulic telescopic rod 422 on the other side begins to move, continuously extending toward the discharge port 414, and ejecting the metal cake from the inner liner of the extrusion chamber 411 through the discharge port 414 with a second preset thrust of 10-15 MPa, ensuring that the formed metal cake is completely ejected from the mold.

[0103] In a preferred embodiment, the push plate 333 has an arc-shaped surface facing the extrusion chamber 411 and an inner surface of the extrusion chamber 411. When the push plate 333 pushes the scrap metal into the extrusion chamber 411, the arc-shaped surface of the push plate 333 aligns with the arc-shaped surface of the extrusion chamber 411, forming a preliminary cylindrical structure for the scrap metal to be extruded. The two extrusion heads 423 then extrude the scrap metal into a compact cylindrical metal cake.

[0104] The ejected cylindrical metal cake rolls down along the inclined discharge slide 51. Since the higher end of the discharge slide 51 is located below the discharge port 414 of the bidirectional extrusion molding unit 4, this inclined design uses gravity to enable the cylindrical metal cake to slide smoothly down to the designated position. At the same time, the multiple water filter holes opened on the discharge slide 51 play a key role. During the rolling process of the cylindrical metal cake, the oil and water brought out when the cylindrical metal cake is ejected by the hydraulic telescopic rod 422 will flow on the discharge slide 51 and drip through the water filter holes. The water collection base 52 located below the discharge slide 51 receives these dripping oil and water, realizes the filtration and collection of the oil and water, and thus completes the entire discharge process.

[0105] Furthermore, the bidirectional extrusion metal scrap cake pressing process realizes efficient metal scrap cake processing through a systematic process. To more clearly describe the process of this process, a preferred method embodiment is applied: a control method for a bidirectional extrusion metal scrap automatic cake pressing production line, which implements the following steps through the central control unit 6:

[0106] Shredding and filtering: The metal waste enters the pre-treatment unit 1, which shreds and filters the received metal waste, and then sends the pre-treated metal waste to the conveying and weighing unit 2;

[0107] Weighing and feeding: the conveying weighing unit 2 detects the weight of the pre-treated metal scrap and sends the metal scrap that meets the preset weight to the gathering and pushing unit 3;

[0108] Gathering and pushing: The gathering and pushing unit 3 gathers and arranges the metal scraps that meet the preset weight, and then pushes the metal scraps into the extrusion cavity 411 of the bidirectional extrusion molding unit 4;

[0109] Bidirectional extrusion molding: The bidirectional extrusion molding unit 4 is used to perform bidirectional extrusion molding on the metal waste in the extrusion chamber 411 to obtain a metal cake. The bidirectional extrusion molding unit 4 pushes the metal cake and the removed oil and water out of the extrusion chamber 411;

[0110] Discharging and oil and water collection: the formed metal cake is sent out of the bidirectional extrusion molding unit 4 and passes through the discharging unit 5 to collect the metal cake, oil and water.

[0111] In the bidirectional extrusion step, the bidirectional extrusion unit 4 pushes the metal cake and the released oil and water out of the extrusion chamber 411. The specific steps include:

[0112] The hydraulic cylinder 421 controls the hydraulic telescopic rod 422 located at the discharge port 414 to retract until it is completely removed from the extrusion chamber 411 , thereby exposing the discharge port 414 that was originally closed by the hydraulic telescopic rod 422 .

[0113] The hydraulic cylinder 421 controls the hydraulic telescopic rod 422 located at the extrusion port 413 to start moving and continuously extend toward the discharge port 414 , and utilizes the thrust to push the metal cake located at the extrusion cavity 411 and the released oil and water out of the discharge port 414 .

[0114] In this control method, the central control unit 6 accurately regulates each production link based on PLC control technology.

[0115] Shredding and Water Filtering: When metal scrap enters the pre-treatment unit 1, the central control unit 6 activates the conveying motor 112 of the loading and conveying device 11, driving the conveyor belt 111. The conveyor belt 111, equipped with a stop bar 114, stably conveys the scrap from the loading port 1211 to the dual-shaft shredder 12. At this point, the central control unit 6 controls the shredding drive motor 1221 of the dual-shaft shredder 12, causing the blades 1223 on the two main shafts 1222 to rotate at high speed, shredding the scrap metal. The shredded metal falls into the hopper 131 of the water filtration device 13. The central control unit 6 activates the screw drive motor 1333, driving the screw 1332. As the material is pushed through the screw barrel 1331, oil and water are discharged through the water filtration port 1335. The filtered material is then discharged from the feed port 1212 and conveyed by the feeding and conveying device 14 to the weighing and conveying device. During the entire process, the central control unit 6 monitors the operating parameters of each device in the pretreatment unit 1 in real time, such as motor speed, current, etc., to ensure that the shredding and water filtering processes are stable and efficient.

[0116] Weighing and feeding: When the feeding conveyor 14 of the pre-processing unit 1 conveys the shredded and filtered metal scrap to the higher end, the metal scrap falls by gravity into the weighing plate 22 in the conveying weighing unit 2 below. The central control unit 6 controls the weight detector to detect the weight of the material in the weighing plate 22 in real time and feeds the data back to the central control unit 6. The central control unit 6 compares the real-time weight data with the preset range. When the weight reaches the preset value, the central control unit 6 issues a command to stop the operation of the pre-processing unit 1 and control the weighing conveyor to transfer the material to the gathering frame 31 of the gathering and pushing unit 3 to achieve precise feeding.

[0117] Material gathering and pushing: After the material enters the material gathering frame 31, the central control unit 6 simultaneously controls the actions of the material gathering cylinder 321 and the material pushing cylinder 331 of the material gathering device 32. The material gathering cylinder 321 drives the material gathering plate 323 to flip downward through the material gathering telescopic rod 322. At the same time, the material pushing cylinder 331 pushes the material pushing telescopic rod 332 to drive the pushing plate 333. The downward-flipped material gathering plate 323 will gradually gather the metal waste that is higher than the edge of the material gathering frame 31 and is randomly piled up into the material gathering frame 31. The forward-pushing plate 333 pushes the sorted material from the material gathering frame 31 into the extrusion cavity 411 of the two-way extrusion molding unit 4 to ensure that the material enters the cavity accurately.

[0118] Bidirectional extrusion molding: After the material enters the extrusion chamber 411, the central control unit 6 controls the hydraulic extrusion device 42 located on both sides of the extrusion chamber 411 to extend the two hydraulic telescopic rods 422, driving the extrusion head 423 to move toward each other, and applying bidirectional pressure to the material in the extrusion chamber 411. During this process, the central control unit 6 monitors the pressure, displacement and other parameters of the hydraulic cylinder in real time through hydraulic servo closed-loop control, and compares them with the preset extrusion parameters to automatically adjust the hydraulic system to ensure the stability of the extrusion process, so that the material is extruded into high-quality metal cakes. After the extrusion is completed, the central control unit 6 controls the hydraulic telescopic rod 422 located at the discharge port 414 to retract, exposing the discharge port 414, and then controls the hydraulic telescopic rod 422 on the other side to continue to extend, pushing the metal cake, the released oil and water out of the discharge port 414 to the discharge unit 5.

[0119] Discharging and oil and water collection: The metal cake slides down the inclined discharging slide 51 to the designated position with the help of gravity. At the same time, the water collecting base 52 of the discharging unit 5 is used to collect the oil and water brought out during the extrusion process, completing the entire production process.

[0120] The central control unit 6 adopts PLC control to realize status monitoring and action coordination of the pretreatment unit 1, conveying weighing unit 2, material gathering and pushing unit 3 and bidirectional extrusion molding unit 4, including hydraulic servo closed-loop control, multi-axis coordinated control and full-process automated management.

[0121] Specifically, the PLC-controlled central control unit 6 collects the operating data of the preprocessing unit 1, the conveying weighing unit 2, the material gathering and pushing unit 3 and the bidirectional extrusion molding unit 4 in real time through various sensors, such as the working status, operating parameters, material weight and other information of the equipment.

[0122] For the pre-processing unit 1, the PLC determines whether the shredding operation is normal based on the motor current, speed and other data of the double-shaft shredding device 12. If an abnormal situation such as overload occurs, the motor power is adjusted or an alarm is issued in time.

[0123] For conveying weighing unit 2, the PLC receives the material weight data fed back by the weighing sensor, compares it with the preset weight parameters, and accurately controls the conveying speed and time to ensure that the weight of the material entering the subsequent unit meets the requirements.

[0124] For the material gathering and pushing unit 3, the PLC implements multi-axis coordinated control, precisely controlling the sequence and force of the pusher 33 and the gathering device 32. Based on material information provided by the conveyor weighing unit 2, the motion of each axis is coordinated to ensure efficient coordination of the pushing and gathering actions, accurately feeding the material into the extrusion chamber 411 of the bidirectional extrusion molding unit 4.

[0125] The bidirectional extrusion unit 4 utilizes closed-loop hydraulic servo control. The PLC monitors the hydraulic cylinder's pressure, displacement, and other parameters in real time, comparing them with target values ​​for extrusion pressure and stroke. If actual parameters deviate from the target, the PLC rapidly adjusts the hydraulic system's flow and pressure, ensuring a stable and precise extrusion process and achieving high-quality molding of the scrap metal.

[0126] In addition, PLC is also responsible for the automated management of the entire process. According to the preset production process and logic, it starts and stops each unit equipment in an orderly manner, coordinates the connection between each unit, and ensures the continuous and stable operation of the entire production line.

[0127] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will be able to devise other specific embodiments of the present invention without inventive effort, and such equivalent variations or substitutions are intended to be encompassed within the scope of the claims of this application.

Claims

1. A metal scrap cake pressing process with high deoiling and dehydration rate, characterized in that: The following steps are involved: Shredding and filtering: Shredding and filtering the delivered metal waste to obtain metal scraps; Weighing and feeding: Check the weight of metal scraps and weigh the metal scraps that meet the preset weight; Gathering and pushing: Gather and sort the metal debris that meets the preset weight, and push the metal debris into the extrusion chamber with a first preset thrust; Bidirectional extrusion molding: According to the preset extrusion conditions, the metal chips in the extrusion cavity are subjected to bidirectional extrusion molding to form metal cakes while removing oil and water; Discharging and collecting oil and water: According to the second preset thrust, the formed metal cake, the released oil and water are pushed out of the extrusion cavity, and the discharging, oil and water are collected.

2. The metal scrap cake pressing process with high deoiling and dehydration rate according to claim 1, characterized in that: In the shredding and water filtering steps, the conveying speed of the metal waste is 0.5-1 m / s.

3. The metal scrap cake pressing process with high deoiling and dehydration rate according to claim 1, characterized in that: In the shredding and water filtering steps, the particle size of the shredded metal waste is in the range of 10-20 cm.

4. The metal scrap cake pressing process with high deoiling and dehydration rate according to claim 1, characterized in that: In the weighing and feeding steps, the preset weight is 40kg-60kg, and the error range of the weight detection is ±10%.

5. The metal scrap cake pressing process with high deoiling and dehydration rate according to claim 1, characterized in that: In the material gathering and pushing steps, the first preset thrust is 10-15 MPa.

6. The metal scrap cake pressing process with high deoiling and dehydration rate according to claim 1, characterized in that: In the bidirectional extrusion molding step, the preset extrusion conditions include an extrusion pressure of 20-35 MPa, an extrusion speed of 0.2-0.5 m / s and an extrusion time of 20-30 s.

7. The metal scrap cake pressing process with high deoiling and dehydration rate according to claim 1, characterized in that: In the discharging and oil-water collecting steps, the second preset thrust is 10-15 MPa.

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