Livestock and poultry manure solid-liquid separation device

Abstract

The utility model discloses a solid-liquid separation device for livestock and poultry manure, belongs to the field of livestock and poultry manure equipment treatment, and aims to improve the dehydration rate of livestock and poultry manure. The device comprises a primary compression unit, an extrusion unit, an adjusting unit, a primary electroosmosis unit and a secondary separation unit, the fourth electroosmosis assembly comprises a secondary negative electrode filter screen, a fourth filter screen connecting piece, a fourth electroosmosis reset piece, a secondary current positive electrode and a secondary direct-current power source, and the secondary negative electrode filter screen is arranged in a fourth treatment pipe and hinged to the inner wall of the fourth treatment pipe through the fourth filter screen connecting piece; the secondary current positive electrode and the secondary negative electrode filter screen are electrically connected with a secondary direct-current power supply respectively, and electroosmosis is generated between the secondary direct-current power supply and the secondary negative electrode filter screen. On the basis of the spiral extrusion equipment, two-stage electroosmosis treatment is adopted, and a migration channel is established in the second-stage electroosmosis treatment, so that the water migration resistance is reduced, and the dehydration efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection, particularly the field of livestock and poultry manure processing equipment, and specifically to a livestock and poultry manure solid-liquid separation device. Based on existing screw extrusion equipment, this application utilizes secondary electro-osmotic dehydration to further reduce the moisture content of livestock and poultry manure without significantly increasing equipment costs, thereby facilitating subsequent fermentation and reuse of livestock and poultry manure. Background Art

[0002] Estimation of total phosphorus load into Poyang Lake basin based on basin zoning[J] (Cui Fang, Wang Hua, Zeng Yichuan, Yan Yuting, Chen Jingwei.. China Rural Water Resources and Hydropower, 2024(1): 189-196) records that, in order to address the causes of the main phosphorus pollution sources in the Poyang Lake basin, basin zoning technology based on pollution source census was used to calculate the total phosphorus pollution load in the entire basin and conduct a quantitative analysis of the phosphorus pollution sources entering the lake. The results showed that: ... the pollution sources are ranked in order of contribution weight as follows: livestock and poultry breeding (48.63%) > urban life (20.01%) > planting (9.71%) > aquaculture (7.37%) > endogenous release (5.52%) > soil erosion (4.6%) > industrial enterprises (1.12%) > rural life (0.89%) > migratory bird droppings (0.46%) > tourism (0.12%). It can be seen that the source of total phosphorus in Poyang Lake mainly comes from terrestrial input, and livestock and poultry breeding (contributing 48.63%) is the primary agricultural non-point source pollution source of total phosphorus indicators, which has a great impact on the environment of the Poyang Lake basin.

[0003] Livestock and poultry manure contains a large amount of organic matter and nutrients such as nitrogen, phosphorus, potassium, and various minerals and trace elements such as calcium, magnesium, and sulfur. After effective treatment, livestock and poultry manure can produce organic fertilizers, biogas, etc., which can not only reduce environmental pollution but also increase the economic value of agricultural waste. In the preparation of organic fertilizers from livestock and poultry manure and its effects on soil nutrition and tomato quality [J] (Li Tao, Zhong Wei, Zhao Jun, et al.. Shandong Science, 2024(3).), Li Tao et al. used livestock and poultry manure as the main raw material and corn straw chaff as the conditioner to produce high-quality organic fertilizer (OF) products and bio-organic fertilizer (BOF) that met the standard NY 884-2021 through bio+nanocomposite molecular film static composting. The results showed that compared with the application of chemical fertilizers alone, the application of organic and inorganic fertilizers can significantly improve the quality of fruits, such as increasing the mass fraction of soluble sugar and vitamin C while effectively reducing the mass fraction of titratable acid and nitrate (p<0.05).

[0004] However, the current effective utilization rate of livestock and poultry manure is low. The main reason is that the high water content of livestock and poultry manure makes it difficult to transport, store, and directly utilize. This, to a certain extent, restricts the development of livestock and poultry manure resource conversion technology. Therefore, solid-liquid separation of manure is an important prerequisite and key link for manure treatment and comprehensive utilization. After solid-liquid separation of livestock and poultry manure, the separated solid material is nearly odorless, has low viscosity, is easy to transport, and can be used directly as organic fertilizer. It is also the basic prerequisite for further product utilization. The separated liquid material can be anaerobic treated to produce biogas, which can be used as fuel or power generation energy, realizing the effective utilization of resources.

[0005] The main components of the solid matter in livestock and poultry manure are more complex depending on the composition of their diet, primarily containing large amounts of organic fiber, bacteria, some fat and protein, water-soluble fiber gel, inorganic salts, and small amounts of digestive secretions. Studies have found that livestock and poultry manure is a multi-component mixture dominated by organic components, and that the water present in it can be divided into free water (in a free state) and bound water (in a colloidal state). Based on electrochemical properties, the common characteristic of bound water is that water molecules combine with organic or charged molecules through chemical bonds or charge adsorption to form hydrocolloids.

[0006] Currently, solid-liquid separation of livestock and poultry manure is primarily achieved through the addition of flocculants, electroosmosis, and mechanical extrusion. Qin Chenghua et al. studied the flocculation treatment of manure wastewater using flocculants. They found that AS combined with polyaluminum chloride (PAC) or PAM, with cationic PAM and AS showing the best results. When 8 mL of 0.2% AS and 1.5 mL of 0.2% PAM were added to a 500 mL water sample, the wastewater's color, turbidity, and COD removal rates reached 94.3%, 96%, and 58.2%, respectively. He Zongjun et al. used a microbial flocculant and PAC to treat pig manure. The combined use of these two agents was more effective than either alone. The optimal flocculation results were achieved by adding 0.5 mL X1801 plus 1 mL PAC, 0.2 mL X1801 plus 1.5 mL PAC, and 0.5 mL X1801 plus 1.5 mL PAC to 80 mL of manure, achieving flocculation rates exceeding 90%. Chai Qinqin et al. used flocculation to treat pig manure. When using flocculation alone, PAC and chitosan (CTS) had the best flocculation effect. When PAC-CTS was used in combination, 4 mL of 50 g / L PAC was first added to 200 mL of manure, and after rapid stirring for 30 seconds, 21 mL of 5 g / L CTS was added. The rapid and slow stirring lasted for a total of 80 seconds. The turbidity, total phosphorus, and CODcr removal rates reached 94.35%, 75.90%, and 85.30%, respectively, and the manure water quality was further improved.

[0007] Regarding electroosmotic dehydration, Yu Xiaoyan et al. used electroosmotic dehydration technology to dehydrate biological sludge and investigated its dehydration performance. Under a pressure of 100 Pa, the water content of hypertonic sludge gradually decreased with increasing electroosmotic dehydration time. The moisture content dropped from 75% after vacuum filtration to 58%. Mao Degang et al. investigated the effect of temperature on electroosmotic dehydration and found that the drying rate decreased with decreasing sludge moisture content, while at the same moisture content, the drying rate increased with increasing temperature. Li Yalin et al. investigated the effects of voltage gradient, mechanical pressure, sludge thickness, and persulfate dosage on dehydration. The results showed that voltage gradient, ammonium persulfate dosage, and sludge thickness all affected the dehydration efficiency during electroosmotic-ammonium persulfate oxidation synergistic sludge dehydration. Given the similarities in composition and properties between livestock and poultry manure and sludge, and based on the results of electroosmotic treatment of sludge, electroosmosis has the potential to be applied to livestock and poultry manure treatment.

[0008] The use of mechanical extrusion to separate the solid and liquid of livestock and poultry manure is a common treatment method with a short treatment cycle and high efficiency. For example, the inventor disclosed a spiral extrusion solid-liquid separation device in the prior application CN201910501859.3, which uses a spiral auger with a variable lead spiral feature and an adjustment device that can adjust the spring compression amount to achieve accurate adjustment of the extrusion pressure. Based on the mutual cooperation between the spiral auger and the pressure regulating device, the force distribution of the extrusion part in the spiral extrusion solid-liquid separation device is made more reasonable, thereby effectively improving the extrusion efficiency.

[0009] How to further improve the dehydration rate of livestock and poultry manure has always been the research direction of many researchers. To this end, the present application provides a livestock and poultry manure solid-liquid separation device. Utility Model Content

[0010] The purpose of the invention of this utility model is to improve a solid-liquid separation device for livestock and poultry manure to improve the dehydration rate of livestock and poultry manure. This application is based on a spiral extrusion device and adopts a two-stage electro-osmosis treatment. By establishing a migration channel in the electro-osmosis treatment at the second end, the water migration resistance is reduced, and the dehydration efficiency is effectively improved. This application can further improve the dehydration rate of livestock and poultry manure, lay the foundation for subsequent harmless treatment, and is not only conducive to solving the environmental pollution problem caused by livestock and poultry manure and realizing environmentally friendly production in the livestock and poultry farming industry, but also conducive to the production of high-quality organic fertilizer products, promote the industrialization process of organic fertilizers, realize the sustainable development of ecological agriculture, achieve the coordinated development of "breeding industry" and "planting industry", and promote the virtuous cycle of agricultural waste treatment and utilization.

[0011] In order to achieve the above objectives, this application adopts the following technical solutions:

[0012] A livestock and poultry manure solid-liquid separation device comprises a primary compression unit, an extrusion unit, a regulating unit, a primary electroosmosis unit, and a secondary separation unit;

[0013] The primary compression unit includes a spiral extrusion cavity, a first fixed end, a first discharge hopper, a spiral auger matched with the spiral extrusion cavity, a second fixed end, a first filter, and a first driving device. The spiral extrusion cavity is in the shape of a tube with two ends open. The first fixed end is connected to an opening at one end of the spiral extrusion cavity, and the first discharge hopper is arranged on the other end opening of the spiral extrusion cavity.

[0014] The first driving device is connected to the spiral auger and can drive the spiral auger to rotate;

[0015] The spiral auger comprises a first spiral extrusion section and a first smooth section connected to the first spiral extrusion section as a whole, wherein the first spiral extrusion section is located between the first fixed end and the first discharge hopper;

[0016] The second fixed end is connected to the spiral extrusion cavity through a connecting rod, and the spiral extrusion cavity can provide support for the second fixed end through the connecting rod; one end of the spiral auger close to the first spiral extrusion section is movably connected to the first fixed end, and the other end of the spiral auger is movably connected to the second fixed end, and the first fixed end and the second fixed end can respectively provide support for the spiral auger;

[0017] The spiral extrusion cavity is respectively provided with a first feed port and a first water outlet, wherein the first feed port is provided at the upper end of the spiral extrusion cavity and the solid-liquid mixture to be processed can enter the interior of the spiral extrusion cavity through the first feed port and be extruded by the spiral auger, the first water outlet is provided at the lower end of the spiral extrusion cavity, the first filter screen is provided between the spiral extrusion cavity and the first spiral extrusion section and the liquid in the solid-liquid mixture can be discharged in sequence through the first filter screen and the first water outlet under the extrusion of the first spiral extrusion section;

[0018] The extrusion unit includes a second stopper, a second extrusion spring, a second spring seat, and a second discharge pipe that cooperate with the first discharge hopper. The second stopper, the second extrusion spring, and the second spring seat are sequentially arranged on the first smooth section, and the second stopper and the second spring seat can respectively move relative to the first smooth section. The two ends of the second extrusion spring are respectively connected to the second stopper and the second spring seat. The second stopper is annular and can be tightly fitted with the first discharge hopper under the pressure of the second extrusion spring to achieve closing of the spiral extrusion cavity.

[0019] The adjusting unit is connected to the second fixed end and the second fixed end can provide support for the adjusting unit. The adjusting unit is connected to the second spring seat and the adjusting unit can adjust the position of the second spring seat to control the discharge pressure of the second stopper.

[0020] The second discharge pipe is connected to the second fixed end and the second fixed end can provide support for the second discharge pipe. The second discharge pipe is located below the second extrusion spring and the material discharged from the first discharge hopper can be discharged through the second discharge pipe.

[0021] It is characterized in that the primary electroosmosis unit includes a primary DC power supply, a primary current positive electrode, and a primary current negative electrode, the primary current positive electrode and the primary current negative electrode are respectively electrically connected to the primary DC power supply, the primary current positive electrode and the primary current negative electrode respectively pass through the spiral extrusion cavity, the working end of the primary current positive electrode and the working end of the primary current negative electrode are respectively located inside the spiral extrusion cavity, the working end of the primary current negative electrode is close to the first water outlet, the working end of the primary current positive electrode is away from the first water outlet, and electroosmosis occurs between the primary current positive electrode and the primary current negative electrode to accelerate the discharge of water in the solid-liquid mixture through the first filter and the first water outlet;

[0022] The secondary separation unit includes a fourth processing tube matched with the second discharge pipe, a fourth dispersion component, a fourth electroosmosis component, a fourth connecting outer tube, and a fourth inner tube component. The fourth processing tube is connected to the second discharge pipe and the material discharged through the second discharge pipe can enter the fourth processing tube;

[0023] The fourth dispersing assembly includes a fourth dispersing support rod, a fourth dispersing rotor, and fourth dispersing blades arranged along the circumference of the fourth dispersing rotor; the fourth dispersing rotor is arranged at one end of the fourth dispersing support rod and the fourth dispersing rotor can freely rotate relative to the fourth dispersing support rod, the other end of the fourth dispersing support rod is connected to the inner wall of the fourth processing tube, and the fourth processing tube can provide support for the fourth dispersing support rod;

[0024] The fourth dispersing blade is arranged to be inclined relative to the axial direction of the fourth dispersing rotor, the fourth dispersing blade is fixedly connected to the fourth dispersing support rod, and the fourth dispersing blade can synchronously drive the fourth dispersing rotor to rotate relative to the axial direction of the fourth dispersing rotor under the action of the material in the fourth processing tube and disperse the material in the fourth processing tube;

[0025] The fourth electroosmotic assembly includes a secondary negative electrode filter, a fourth filter connector, a fourth electroosmotic reset member, a secondary current positive electrode, and a secondary DC power supply. The secondary negative electrode filter is disposed in a fourth processing tube. The secondary negative electrode filter is hingedly connected to the inner wall of the fourth processing tube via the fourth filter connector, and the secondary negative electrode filter can be opened or closed relative to the fourth processing tube so that material on the secondary negative electrode filter can fall through an opening formed when the secondary negative electrode filter is opened relative to the fourth processing tube.

[0026] The fourth electroosmotic reset member is located below the secondary negative electrode filter and can provide support for the secondary negative electrode filter so that the secondary negative electrode filter can be maintained in its initial position;

[0027] There are a plurality of secondary current positive electrodes, each of which is connected to a fourth processing tube and can provide support for the secondary current positive electrodes; the secondary current positive electrodes are located between the secondary negative electrode filter and the fourth dispersion blade and can vertically divide the material in the fourth processing tube;

[0028] The secondary current positive electrode and the secondary negative electrode filter are respectively electrically connected to the secondary DC power supply, and electroosmosis occurs between the secondary DC power supply and the secondary negative electrode filter to accelerate the precipitation of water in the material in the fourth processing tube;

[0029] The fourth connecting outer tube is connected to the lower end of the fourth processing tube;

[0030] The fourth inner tube assembly includes a first inner tube connecting portion and a second inner tube connecting portion, wherein the first inner tube connecting portion is in an inverted conical hollow tube shape, and the second inner tube connecting portion is in a tubular shape;

[0031] The first connecting portion of the inner tube is located inside the fourth connecting outer tube, the upper end opening of the first connecting portion of the inner tube is connected to the fourth processing tube, the lower end opening of the first connecting portion of the inner tube is connected to the second connecting portion of the inner tube, the second connecting portion of the inner tube passes through the fourth connecting outer tube, and the material in the fourth processing tube can be discharged through the second connecting portion of the inner tube after passing through the first connecting portion of the inner tube;

[0032] The wall of the first inner tube connection portion is provided with a plurality of first inner tube through holes, and the liquid in the fourth processing tube can be discharged in sequence through the first inner tube through holes and the fourth connecting outer tube during the process of falling along the wall of the first inner tube connection portion.

[0033] The fourth dispersion support rod is L-shaped.

[0034] There is at least one fourth filter screen connecting member, and the fourth filter screen connecting member is a hinge.

[0035] There is at least one fourth electroosmotic reset component, and the fourth electroosmotic reset component is a torsion spring.

[0036] The torsion spring is connected to the fourth processing tube and the fourth processing tube can provide support for the torsion spring;

[0037] One end of the torsion spring is supported by the inner wall of the fourth processing tube, and the other end of the torsion spring is connected to the secondary negative electrode filter. The torsion spring can provide an upward supporting force for the secondary negative electrode filter.

[0038] One end of the torsion spring is attached to the lower side of the secondary negative electrode filter.

[0039] The secondary negative electrode filter is circular.

[0040] There are 2 to 10 secondary current positive electrodes, which are arranged in parallel in the fourth processing tube.

[0041] The area in the fourth treatment tube between the secondary current positive electrode and the secondary negative electrode filter is recorded as the secondary electroosmosis area;

[0042] A second insulating protective layer is provided on the outer wall of the secondary electroosmosis area on the fourth processing tube, and a layer of insulating paint is provided on the inner wall of the threaded connection hole between the secondary current positive electrode and the fourth processing tube, and on the inner wall of the threaded connection hole between the connecting part of the secondary negative electrode filter and the fourth processing tube.

[0043] The second connecting portion of the inner tube is in the shape of a circular tube with equal diameter.

[0044] The area between the primary current positive electrode and the primary current negative electrode on the spiral extrusion cavity is recorded as the spiral extrusion-primary infiltration area;

[0045] A first insulating protective layer is provided on the outer wall of the spiral extrusion-seepage area on the spiral extrusion cavity, and a layer of insulating paint is provided on the inner wall of the threaded connection hole between the primary current positive pole and the spiral extrusion cavity and the inner wall of the threaded connection hole between the primary current negative pole and the spiral extrusion cavity.

[0046] The first driving device is a motor.

[0047] The adjusting unit includes a third rotating rod, a third adjusting push rod, a third rotating nut, and an adjusting hand wheel. The third rotating rod is movably connected to the second fixed end and can rotate relative to the second fixed end. The third rotating nut is provided on the third rotating rod. The third rotating nut is threadedly connected to the third rotating rod and can move axially relative to the third rotating rod.

[0048] The adjusting hand wheel is fixedly connected to the third rotating rod;

[0049] There are at least two third adjusting push rods, and both ends of the third adjusting push rods are fixedly connected to the third rotating nut and the second spring seat respectively. The third rotating nut can drive the second spring seat to squeeze the second extrusion spring through the third adjusting push rod to adjust the discharge pressure of the second stopper.

[0050] The third adjusting push rod passes through the second fixed end and the second fixed end can provide support for the third adjusting push rod.

[0051] The first spiral extrusion section adopts a constant diameter design.

[0052] The first spiral extrusion section adopts a constant pitch design;

[0053] Alternatively, the first spiral extrusion section adopts a variable pitch design, and the pitch of the first spiral extrusion section gradually decreases along the direction from the first fixed end to the second fixed end. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 The effect of electroosmosis at different voltages on the moisture content of pig manure.

[0055] Figure 2 The graph shows the change of current under different voltage gradients.

[0056] Figure 3 This is a structural diagram of the combination of a primary compression unit, an extrusion unit, an adjustment unit and a primary electroosmosis unit in Example 1.

[0057] Figure 4 yes Figure 3 side view.

[0058] Figure 5 It is a structural diagram of the secondary separation unit.

[0059] Figure 6 It is a structural diagram of the secondary negative filter when it is opened relative to the fourth processing tube.

[0060] Markings in the figure: 1. spiral extrusion cavity, 2. first fixed end, 3. first discharge hopper, 4. spiral auger, 5. second fixed end, 6. first filter screen, 7. first drive device, 8. first feed port, 9. first water outlet, 11. second stop block, 12. second extrusion spring, 13. second spring seat, 14. second discharge pipe, 15. adjustment unit, 16. primary current positive electrode, 17. primary current negative electrode, 21. fourth processing tube, 22. fourth dispersion support rod, 23. fourth dispersion rotor, 24. secondary negative electrode filter screen, 25. secondary current positive electrode, 26. fourth electroosmosis reset member, 27. fourth connecting outer tube, 28. first connecting part of inner tube, 29. second connecting part of inner tube. DETAILED DESCRIPTION

[0061] The present invention will be described in detail below with reference to the accompanying drawings.

[0062] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0063] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0064] Example 1

[0065] (1) Test method

[0066] 1. Determination of moisture content of fresh pig manure

[0067] Pour fresh pig manure into a crucible, place the crucible on a universal electric furnace, and dry for 10 hours. Calculate the moisture content of the fresh pig manure, ω, based on the weights taken before and after the drying test. The calculation formula is as follows:

[0068] (1);

[0069] In formula (1), m0 is the weight of the crucible, m1 is the total weight of fresh pig manure and the crucible, and m2 is the total weight of dry manure and the crucible.

[0070] 2. Determination of moisture content of pig manure after dehydration

[0071] The calculation formula for determining the moisture content of dehydrated pig manure is as follows:

[0072] (2);

[0073] In formula (2), ω1 is the moisture content of the pig manure cake after dehydration, m3 is the mass of water removed from the pig manure cake, and m4 is the initial mass of the manure cake.

[0074] (2) Equipment structure

[0075] As mentioned above, the inventors previously disclosed a spiral extrusion solid-liquid separation device. In order to improve the dehydration efficiency of livestock and poultry manure, in the early stage of the experiment, the inventors adopted a method that combines the addition of flocculants, mechanical extrusion, and the installation of an electro-osmosis device in the mechanical extrusion equipment. In subsequent actual understanding, the inventors found that when adding flocculants to treat livestock and poultry manure, there are corresponding ratio requirements between livestock and poultry manure and flocculants. It is often difficult for farmers to grasp the precise flocculant addition ratio, which will affect the dehydration rate of livestock and poultry manure to a certain extent. At the same time, this method requires the use of separate chemical reagents, which increases the use and maintenance costs of farmers to a certain extent, and is not conducive to the promotion and application of the device. Based on the above considerations, the inventors finally chose a method that combines mechanical extrusion and the installation of an electro-osmosis device in the mechanical extrusion equipment to improve the dehydration rate of livestock and poultry manure.

[0076] Furthermore, the inventors discovered during subsequent experiments that, compared to simple mechanical extrusion, setting a corresponding electroosmosis device in the mechanical extrusion equipment is beneficial to improving the dehydration rate of livestock and poultry manure. In the early stage of the experiment, the inventors only set up a single electroosmosis unit in the extrusion unit, hoping to achieve effective dehydration of livestock and poultry manure by combining spiral extrusion with a single electroosmosis. The experimental results show that, compared to the single spiral extrusion method, the combination of spiral extrusion and a single electroosmosis can further improve the dehydration rate of livestock and poultry manure. However, the inventors also found that, using this method, the dehydrated livestock and poultry manure often has the phenomenon of being dry on the outside and wet on the inside, which affects the further reduction of the dehydration rate.

[0077] The relevant test records are as follows.

[0078] Weigh 50g of fresh pig manure, control the mechanical pressure to 500KPa, and filter through the mechanical filter for 30 minutes. Then wrap the pig manure with 100-mesh filter cloth and place it in a homemade electro-osmosis dehydration device for electro-osmosis dehydration. Dehydrate at different voltages (10, 15, 20, 25, 30V) for 30 minutes to verify whether the electro-osmosis dehydration is effective. The test results are as follows: Figure 1 shown.

[0079] from Figure 1 It can be seen that electroosmosis can achieve deep dehydration of pig manure based on a 30-minute mechanical filter press, and the moisture content of the manure sample decreases with increasing voltage. Therefore, electroosmosis can achieve deep dehydration of pig manure, and the moisture content of the manure sample decreases with increasing voltage. After analysis, the inventors believe that capillary water and adsorbed water attached to manure particles, water within the manure particles, and interstitial water between particles, under the action of electroosmosis, accumulate on the manure surface, and then precipitate water molecules through the filter pores on the electrode plates, thereby achieving the purpose of dehydration.

[0080] Dehydration was effective at all voltage gradients for the first 20 minutes, but then declined and plateaued. Ultimately, the moisture content of pig manure decreased from 64.3% to 56.84% after electroosmotic dehydration, a reduction of 5% to 8%. Increasing the voltage accelerated the movement of water from the anode to the cathode, improving the dehydration effect.

[0081] At the same time, the inventors found that in the electroosmotic dehydration before 5 minutes, the current first increased rapidly, reached a peak and then slowly decreased. The greater the voltage, the greater the peak current. The test results are as follows: Figure 2 shown. Figure 2 In the figure, curves 1, 2, 3, 4, and 5, from top to bottom, correspond to voltages of 30V, 25V, 20V, 15V, and 10V, respectively. Given that increasing the electroosmotic voltage from 25V to 30V only reduces the fecal moisture content by 0.2%, 25V is the optimal voltage for dehydration efficiency and energy consumption.

[0082] After research, the inventors concluded that in the initial stages of electroosmotic dehydration, the resistance of the pig manure cake is constant. Under the influence of the electric field, the ion migration rate slowly accelerates, the resistance decreases, the current rapidly rises to a peak, and the water in the manure cake pores rapidly moves toward the cathode, dehydrating the manure. As electroosmosis continues, dehydration near the anode causes an unsaturated layer to appear in the fecal sample, increasing the resistance while decreasing the current and reducing the dehydration efficiency. On the one hand, the gas produced by the electrochemical reaction forms a gas film at the anode and cathode, increasing the resistance to water migration. On the other hand, as the temperature gradually rises, the manure cake continues to lose moisture, causing localized cracking of the manure in the anode area, reducing the contact area between the manure cake and the anode, and the electroosmotic dehydration reaches its dehydration limit, resulting in dehydration cessation.

[0083] In summary, using this method, there are certain limitations on the improvement of the dehydration rate of livestock and poultry manure. How to further improve the dehydration rate of livestock and poultry manure at a low cost has become an urgent problem to be solved. To this end, this embodiment provides a livestock and poultry manure solid-liquid separation device to solve the above problem.

[0084] This embodiment provides a solid-liquid separation device for livestock and poultry manure, comprising a primary compression unit, an extrusion unit, a regulating unit, a primary electroosmosis unit, and a secondary separation unit. The primary compression unit comprises a spiral extrusion chamber, a first fixed end, a first discharge hopper, a spiral auger mating with the spiral extrusion chamber, a second fixed end, a first filter, and a first drive device. The spiral extrusion chamber is tubular with two openings at both ends. The first fixed end is connected to one opening of the spiral extrusion chamber, and the first discharge hopper is disposed at the other opening of the spiral extrusion chamber.

[0085] The first drive device is connected to the spiral auger and the first drive device can drive the spiral auger to rotate. In a specific embodiment, the first drive device is a motor. The spiral auger includes a first spiral extrusion section and a first smooth section connected to the first spiral extrusion section as a whole. The first spiral extrusion section is located between the first fixed end and the first discharge hopper. The second fixed end is connected to the spiral extrusion cavity through a connecting rod, and the spiral extrusion cavity can provide support for the second fixed end through the connecting rod. One end of the spiral auger close to the first spiral extrusion section is movably connected to the first fixed end, and the other end of the spiral auger is movably connected to the second fixed end. The first fixed end and the second fixed end can respectively provide support for the spiral auger.

[0086] In this embodiment, the spiral extrusion chamber is provided with a first feed inlet and a first water outlet. The first feed inlet is located at the upper end of the spiral extrusion chamber, and the first water outlet is located at the lower end of the spiral extrusion chamber. The first filter is located between the spiral extrusion chamber and the first spiral extrusion section. With this structure, the solid-liquid mixture to be processed can enter the spiral extrusion chamber through the first feed inlet and be extruded by the spiral auger. Under the pressure of the first spiral extrusion section, the liquid in the solid-liquid mixture is discharged through the first filter and the first water outlet in sequence.

[0087] The first spiral extrusion section adopts a constant diameter design. Furthermore, the first spiral extrusion section adopts a constant pitch design; or the first spiral extrusion section adopts a variable pitch design, where the pitch of the first spiral extrusion section gradually decreases from the first fixed end to the second fixed end. The gradual variable pitch design of the first spiral extrusion section is beneficial for improving extrusion efficiency.

[0088] In this embodiment, the extrusion unit includes a second stopper, a second extrusion spring, a second spring seat, and a second discharge pipe that cooperate with the first discharge hopper. The second stopper, second extrusion spring, and second spring seat are sequentially arranged on the first smooth section, and the second stopper and second spring seat are each movable relative to the first smooth section. Simultaneously, the second extrusion spring is connected at both ends to the second stopper and second spring seat, respectively. The second stopper is annular in shape, and under the pressure of the second extrusion spring, the second stopper can be tightly fitted with or relatively separated from the first discharge hopper to close or open the spiral extrusion chamber. An adjustment unit is connected to the second fixed end, which provides support for the adjustment unit. The adjustment unit is connected to the second spring seat, which can adjust the position of the second spring seat to control the discharge pressure of the second stopper. The second discharge pipe is connected to the second fixed end, which provides support for the second discharge pipe. Simultaneously, the second discharge pipe is located below the second extrusion spring, and material discharged from the first discharge hopper can be discharged through the second discharge pipe.

[0089] The primary electroosmosis unit includes a primary DC power supply, a primary current positive electrode, and a primary current negative electrode, each electrically connected to the primary DC power supply. Simultaneously, the primary current positive electrode and the primary current negative electrode each pass through a spiral extrusion cavity, with the working ends of the primary current positive electrode and the primary current negative electrode located within the spiral extrusion cavity. The working end of the primary current negative electrode is located near the first water outlet, while the working end of the primary current positive electrode is located away from the first water outlet. Electroosmosis occurs between the primary current positive electrode and the primary current negative electrode to accelerate the discharge of water from the solid-liquid mixture through the first filter and the first water outlet.

[0090] Preferably, the area on the spiral extrusion cavity between the primary current positive pole and the primary current negative pole is recorded as the spiral extrusion-one-seepage area; a first insulating protective layer is provided on the outer wall of the spiral extrusion-one-seepage area on the spiral extrusion cavity, and a layer of insulating paint is provided on the inner wall of the threaded connection hole between the primary current positive pole and the spiral extrusion cavity, and the inner wall of the threaded connection hole between the primary current negative pole and the spiral extrusion cavity.

[0091] The secondary separation unit includes a fourth processing tube that cooperates with the second discharge tube, a fourth dispersion assembly, a fourth electroosmosis assembly, a fourth connecting outer tube, and a fourth inner tube assembly. The fourth processing tube is connected to the second discharge tube, and the material discharged through the second discharge tube can enter the fourth processing tube.

[0092] The fourth dispersion component includes a fourth dispersion support rod, a fourth dispersion rotor, and a fourth dispersion blade arranged along the circumference of the fourth dispersion rotor. The fourth dispersion rotor is arranged at one end of the fourth dispersion support rod, and the fourth dispersion rotor can rotate freely relative to the fourth dispersion support rod; the other end of the fourth dispersion support rod is connected to the inner wall of the fourth processing tube, and the fourth processing tube can provide support for the fourth dispersion support rod. The fourth dispersion blade is arranged to be tilted relative to the axial direction of the fourth dispersion rotor, and the fourth dispersion blade is fixedly connected to the fourth dispersion support rod. Furthermore, the fourth dispersion support rod is L-shaped. With this structure, since the fourth dispersion blade is arranged to be tilted relative to the axial direction of the fourth dispersion rotor, the force at different radii of the fourth dispersion blade is uneven, thereby driving the fourth dispersion blade to rotate itself; in the process of rotation of the fourth dispersion blade, the solid material is dispersed and processed, effectively solving the problem of the solid material being dry on the outside and wet on the inside; at the same time, the dispersion process is conducive to establishing channels for dehydration of livestock and poultry manure, and increasing channels for the precipitation of water molecules during the dehydration process. In this embodiment, the fourth dispersion component adopts the form of passive motion, which has the following advantages: (1) Due to the passive dispersion form, the overall structure is simpler and the cost is lower; (2) The installation of external drive devices such as motors is avoided, which can reduce the equipment maintenance cost; if the motor is placed in the fourth processing hall, the material will be located near the motor for a long time, and heat dissipation and material blockage of the motor will become problems; (3) If external drive devices such as motors are introduced, the motors need to be sealed accordingly, which will lead to a significant increase in the overall cost and cannot meet the needs of farmers for extensive use.

[0093] The fourth electroosmosis component includes a secondary negative electrode filter, a fourth filter connector, a fourth electroosmosis reset component, a secondary current positive electrode, and a secondary DC power supply. The secondary negative electrode filter is disposed within the fourth processing tube, and the secondary negative electrode filter is hinged to the inner wall of the fourth processing tube via the fourth filter connector. The secondary negative electrode filter can be opened or closed relative to the fourth processing tube, so that the material on the secondary negative electrode filter can fall through the opening formed when the secondary negative electrode filter is opened relative to the fourth processing tube. At the same time, the fourth electroosmosis reset component is located below the secondary negative electrode filter, and the fourth electroosmosis reset component can provide support for the secondary negative electrode filter so that the secondary negative electrode filter can maintain its initial position. Furthermore, the secondary negative electrode filter is circular; there are two fourth filter connectors, and the fourth filter connector is a hinge. There are two fourth electroosmotic reset parts, which are torsion springs; preferably, the torsion springs are connected to the fourth processing tube, and the fourth processing tube can provide support for the torsion springs; one end of the torsion spring is supported by the inner wall of the fourth processing tube, and the other end of the torsion spring is connected to the secondary negative electrode filter; further, one end of the torsion spring is attached to the bottom of the secondary negative electrode filter.

[0094] In this structure, the secondary negative electrode filter has the following two functions: (1) serving as the negative electrode for electroosmosis treatment; (2) playing a supporting role. Specifically, the secondary negative electrode filter can rotate relative to the wall of the fourth treatment tube through the fourth filter connector; during the rotation of the fourth filter connector, the outer wall of the fourth filter connector separates from the inner wall of the fourth treatment tube, forming a corresponding opening between the fourth filter connector and the fourth treatment tube, and the material on the fourth filter connector can fall downward through the formed opening; at the same time, the torsion spring can provide an upward supporting force for the secondary negative electrode filter, which can make the outer wall of the fourth filter connector fit on the inner wall of the fourth treatment tube and keep the material on the secondary negative electrode filter; when the gravity of the material on the fourth filter connector is greater than the supporting force of the torsion spring, the fourth filter connector and the fourth treatment tube separate from each other, causing the corresponding opening to open, and the material on the fourth filter connector falls from the opening into the fourth inner tube assembly.

[0095] In this embodiment, there are multiple secondary current positive electrodes, which are connected to a fourth processing tube, and the fourth processing tube can provide support for the secondary current positive electrodes. The secondary current positive electrode is located between the secondary negative electrode filter and the fourth dispersion blade, and the secondary current positive electrode can vertically divide the material in the fourth processing tube. The secondary current positive electrode and the secondary negative electrode filter are each electrically connected to a secondary DC power supply, and electroosmosis occurs between the secondary DC power supply and the secondary negative electrode filter to accelerate the precipitation of water from the material in the fourth processing tube. In one specific embodiment, there are four secondary current positive electrodes, which are arranged in parallel within the fourth processing tube. Furthermore, the area within the fourth processing tube between the secondary current positive electrode and the secondary negative electrode filter is designated as the secondary electroosmosis area; a second insulating protective layer is provided on the outer wall of the secondary electroosmosis area on the fourth processing tube, and a layer of insulating varnish is provided on the inner wall of the threaded connection hole between the secondary current positive electrode and the fourth processing tube, and on the inner wall of the threaded connection hole between the connecting piece of the secondary negative electrode filter and the fourth processing tube. In this structure, the secondary current positive electrode has the following two functions: (1) serving as the positive electrode for electroosmosis treatment; and (2) acting as a segmentation. Specifically, the four secondary current positive electrodes are arranged in parallel, thus acting like a fence, effectively segmenting the solid material.

[0096] Secondary electroosmosis is achieved through the coordination of the secondary negative filter, the secondary current positive electrode, and the secondary DC power supply. During the secondary electroosmosis process, based on the dispersing effect of the fourth dispersing blade and the secondary current positive electrode, a channel for dehydrating livestock and poultry manure is constructed, thereby effectively solving the problem of excessive overall resistance of the solid material and resulting in too low current after the primary electroosmosis. The principle of secondary electroosmosis is as follows: the material as a whole is electrically neutral, so the medium surrounding the particles must contain excess ions with an equal number and opposite sign to the surface charge of the particles. These ions are called counterions; the surface charge of the particles and the counterions in the surrounding medium form the so-called double layer; during the secondary electroosmosis process, the charged particles move in the electric field; under the action of the electric field, the charged particles are fixed, while the liquid phase moves in a directional manner, thereby achieving dehydration of the material.

[0097] The fourth inner tube assembly includes an inner tube first connection part and an inner tube second connection part. The inner tube first connection part is an inverted cone-shaped hollow tube, and the inner tube second connection part is tubular. The inner tube first connection part is located inside the fourth connecting outer tube, the upper end opening of the inner tube first connection part is connected to the fourth processing tube, the lower end opening of the inner tube first connection part is connected to the inner tube second connection part, the inner tube second connection part passes through the fourth connecting outer tube, and the material in the fourth processing tube can be discharged through the inner tube second connection part after passing through the inner tube first connection part. At the same time, a plurality of inner tube first through holes are provided on the tube wall of the inner tube first connection part, and the liquid in the fourth processing tube can be discharged through the inner tube first through holes and the fourth connecting outer tube in sequence during the process of falling along the tube wall of the inner tube first connection part. In this embodiment, the sleeve design of the fourth connecting outer tube and the fourth inner tube assembly is adopted to meet the different discharge requirements of liquid materials and solid materials. Preferably, the inner tube second connection part is in the shape of an equal-diameter circular tube.

[0098] The working process of the device is as follows:

[0099] (1) The solid-liquid mixture can enter the interior of the spiral extrusion cavity through the first feed port and be extruded by the spiral auger; under the extrusion of the first spiral extrusion section, part of the liquid in the solid-liquid mixture is discharged through the first filter screen and the first water outlet in sequence;

[0100] (2) Under the action of the primary electroosmosis unit, part of the liquid in the solid-liquid mixture precipitates and is discharged through the first filter and the first outlet in sequence;

[0101] (3) The solid material produced by extrusion passes through the opening between the first discharge hopper and the second stopper, enters the second discharge pipe, and is discharged through the second discharge pipe;

[0102] (4) The material entering the second discharge pipe drives the fourth dispersing blade to rotate due to its own gravity; during the rotation of the fourth dispersing blade, the blade disperses the solid material and establishes a channel for dehydrating livestock and poultry manure;

[0103] (5) As the solid material falls in the fourth treatment tube, it is first split by the positive electrode of the secondary current and temporarily stored on the secondary negative filter. At this time, the fourth electroosmosis component works to achieve secondary electroosmosis treatment. Under the action of the secondary electroosmosis treatment, part of the liquid in the material precipitates and falls through the mesh on the secondary negative filter, while the solid material temporarily stays on the secondary negative filter.

[0104] (6) The liquid falling on the secondary negative electrode filter is discharged in sequence through the first through hole of the inner tube on the first connecting part of the inner tube and the fourth connecting outer tube;

[0105] When the gravity of the material on the fourth filter screen connector is greater than the supporting force of the torsion spring, the fourth filter screen connector and the fourth processing tube are separated from each other, so that the corresponding opening is opened, and the material on the fourth filter screen connector falls from the opening into the fourth inner tube assembly, completing the corresponding solid-liquid separation operation.

[0106] The test results show that compared with spiral extrusion and primary electroosmosis treatment, the present application adopts a combination of spiral extrusion, primary electroosmosis treatment and secondary electroosmosis treatment, which can further reduce the moisture content of livestock and poultry manure by about 5~12%, and has a significant dehydration effect.

[0107] In summary, the device of this application can significantly improve the dehydration rate of livestock and poultry manure, thereby meeting the subsequent treatment needs of livestock and poultry manure. The application can effectively promote the ecological development of environmentally friendly animal husbandry, open up the market for livestock and poultry manure treatment technology and equipment, and promote the sustainable development of livestock and poultry manure resource utilization.

[0108] It should be noted that, in order to simplify the presentation of this specification and facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

Claims

1. A livestock and poultry manure solid-liquid separation device, comprising a primary compression unit, an extrusion unit, a regulating unit, a primary electroosmosis unit, and a secondary separation unit; The primary compression unit includes a spiral extrusion cavity, a first fixed end, a first discharge hopper, a spiral auger matched with the spiral extrusion cavity, and a first filter screen. The spiral extrusion cavity is in a tubular shape with two ends open. The first fixed end is connected to an opening at one end of the spiral extrusion cavity, and the first discharge hopper is arranged on the other end opening of the spiral extrusion cavity. The spiral extrusion cavity is respectively provided with a first feed port and a first water outlet, wherein the first feed port is provided at the upper end of the spiral extrusion cavity and the solid-liquid mixture to be processed can enter the spiral extrusion cavity through the first feed port and be extruded by the spiral auger, the first water outlet is provided at the lower end of the spiral extrusion cavity, the first filter screen is provided in the spiral extrusion cavity and the liquid in the solid-liquid mixture can be discharged in sequence through the first filter screen and the first water outlet; The extrusion unit includes a second stopper, a second extrusion spring, a second spring seat, and a second discharge pipe that cooperate with the first discharge hopper. The second stopper, the second extrusion spring, and the second spring seat are sequentially arranged on the first smooth section, and the second stopper and the second spring seat can respectively move relative to the first smooth section. The two ends of the second extrusion spring are respectively connected to the second stopper and the second spring seat. The second stopper is annular and can be tightly fitted with the first discharge hopper under the pressure of the second extrusion spring to achieve closing of the spiral extrusion cavity. The adjusting unit is connected to the second fixed end and the second fixed end can provide support for the adjusting unit. The adjusting unit is connected to the second spring seat and the adjusting unit can adjust the position of the second spring seat to control the discharge pressure of the second stopper. The second discharge pipe is connected to the second fixed end and the second fixed end can provide support for the second discharge pipe. The second discharge pipe is located below the second extrusion spring and the material discharged from the first discharge hopper can be discharged through the second discharge pipe. It is characterized in that The primary electroosmosis unit includes a primary DC power supply, a primary current positive electrode, and a primary current negative electrode, wherein the primary current positive electrode and the primary current negative electrode are electrically connected to the primary DC power supply, respectively, and the primary current positive electrode and the primary current negative electrode respectively pass through a spiral extrusion cavity, wherein the working end of the primary current positive electrode and the working end of the primary current negative electrode are respectively located inside the spiral extrusion cavity, the working end of the primary current negative electrode is close to the first water outlet, the working end of the primary current positive electrode is away from the first water outlet, and electroosmosis occurs between the primary current positive electrode and the primary current negative electrode to accelerate the discharge of water in the solid-liquid mixture through the first filter screen and the first water outlet; The secondary separation unit includes a fourth processing tube matched with the second discharge pipe, a fourth dispersion component, a fourth electroosmosis component, a fourth connecting outer tube, and a fourth inner tube component. The fourth processing tube is connected to the second discharge pipe and the material discharged through the second discharge pipe can enter the fourth processing tube; The fourth dispersing assembly includes a fourth dispersing support rod, a fourth dispersing rotor, and fourth dispersing blades arranged along the circumference of the fourth dispersing rotor; the fourth dispersing rotor is arranged at one end of the fourth dispersing support rod and the fourth dispersing rotor can freely rotate relative to the fourth dispersing support rod, the other end of the fourth dispersing support rod is connected to the inner wall of the fourth processing tube, and the fourth processing tube can provide support for the fourth dispersing support rod; The fourth dispersing blade is arranged to be inclined relative to the axial direction of the fourth dispersing rotor, the fourth dispersing blade is fixedly connected to the fourth dispersing support rod, and the fourth dispersing blade can synchronously drive the fourth dispersing rotor to rotate relative to the axial direction of the fourth dispersing rotor under the action of the material in the fourth processing tube and disperse the material in the fourth processing tube; The fourth electroosmotic assembly includes a secondary negative electrode filter, a fourth filter connector, a fourth electroosmotic reset member, a secondary current positive electrode, and a secondary DC power supply. The secondary negative electrode filter is disposed in a fourth processing tube. The secondary negative electrode filter is hingedly connected to the inner wall of the fourth processing tube via the fourth filter connector, and the secondary negative electrode filter can be opened or closed relative to the fourth processing tube so that material on the secondary negative electrode filter can fall through an opening formed when the secondary negative electrode filter is opened relative to the fourth processing tube. The fourth electroosmotic reset member is located below the secondary negative electrode filter and can provide support for the secondary negative electrode filter so that the secondary negative electrode filter can be maintained in its initial position; There are a plurality of secondary current positive electrodes, each of which is connected to a fourth processing tube and can provide support for the secondary current positive electrodes; the secondary current positive electrodes are located between the secondary negative electrode filter and the fourth dispersion blade and can vertically divide the material in the fourth processing tube; The secondary current positive electrode and the secondary negative electrode filter are respectively electrically connected to the secondary DC power supply, and electroosmosis occurs between the secondary DC power supply and the secondary negative electrode filter to accelerate the precipitation of water in the material in the fourth processing tube; The fourth connecting outer tube is connected to the lower end of the fourth processing tube; The fourth inner tube assembly includes a first inner tube connecting portion and a second inner tube connecting portion, wherein the first inner tube connecting portion is in an inverted conical hollow tube shape, and the second inner tube connecting portion is in a tubular shape; The first connecting portion of the inner tube is located inside the fourth connecting outer tube, the upper end opening of the first connecting portion of the inner tube is connected to the fourth processing tube, the lower end opening of the first connecting portion of the inner tube is connected to the second connecting portion of the inner tube, the second connecting portion of the inner tube passes through the fourth connecting outer tube, and the material in the fourth processing tube can be discharged through the second connecting portion of the inner tube after passing through the first connecting portion of the inner tube; The wall of the first inner tube connection portion is provided with a plurality of first inner tube through holes, and the liquid in the fourth processing tube can be discharged in sequence through the first inner tube through holes and the fourth connecting outer tube during the process of falling along the wall of the first inner tube connection portion.

2. The livestock and poultry manure solid-liquid separation device according to claim 1, characterized in that: The fourth dispersion support rod is L-shaped.

3. The livestock and poultry manure solid-liquid separation device according to claim 1, characterized in that: There is at least one fourth filter screen connecting member, and the fourth filter screen connecting member is a hinge.

4. The livestock and poultry manure solid-liquid separation device according to claim 1, characterized in that: There is at least one fourth electroosmotic reset component, and the fourth electroosmotic reset component is a torsion spring.

5. The livestock and poultry manure solid-liquid separation device according to claim 4, characterized in that: The torsion spring is connected to the fourth processing tube and the fourth processing tube can provide support for the torsion spring; One end of the torsion spring is supported by the inner wall of the fourth processing tube, and the other end of the torsion spring is connected to the secondary negative electrode filter. The torsion spring can provide an upward supporting force for the secondary negative electrode filter.

6. The livestock and poultry manure solid-liquid separation device according to claim 5, characterized in that: One end of the torsion spring is attached to the lower side of the secondary negative electrode filter.

7. The livestock and poultry manure solid-liquid separation device according to claim 1, characterized in that: There are 2 to 10 secondary current positive electrodes, which are arranged in parallel in the fourth processing tube.

8. The livestock and poultry manure solid-liquid separation device according to any one of claims 1 to 7, characterized in that: The area in the fourth treatment tube between the secondary current positive electrode and the secondary negative electrode filter is recorded as the secondary electroosmosis area; A second insulating protective layer is provided on the outer wall of the secondary electroosmosis area on the fourth processing tube, and a layer of insulating paint is provided on the inner wall of the threaded connection hole between the secondary current positive electrode and the fourth processing tube, and on the inner wall of the threaded connection hole between the connecting part of the secondary negative electrode filter and the fourth processing tube.

9. The livestock and poultry manure solid-liquid separation device according to claim 1, characterized in that: The second connecting portion of the inner tube is in the shape of a circular tube with equal diameter.

10. The livestock and poultry manure solid-liquid separation device according to any one of claims 1 to 9, characterized in that: The area between the primary current positive electrode and the primary current negative electrode on the spiral extrusion cavity is recorded as the spiral extrusion-primary infiltration area; A first insulating protective layer is provided on the outer wall of the spiral extrusion-seepage area on the spiral extrusion cavity, and a layer of insulating paint is provided on the inner wall of the threaded connection hole between the primary current positive pole and the spiral extrusion cavity and the inner wall of the threaded connection hole between the primary current negative pole and the spiral extrusion cavity.

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