Method for synthesizing artificial soil by using solid waste

Abstract

The invention discloses a method for synthesizing artificial soil by using solid waste, which comprises the following steps: a, primary mixing: mixing 1-3 parts by weight of river sludge, 1-2 parts by weight of fly ash, 1-2 parts by weight of livestock manure, 0.2-0.4 part by weight of zeolite powder and 0.1-0.2 part by weight of leavening agent by using solid waste mixing equipment, b, fermenting and covering a film for high-temperature oxygen-consuming fermentation to obtain a mixture A, and c, mixing: mixing the mixture A and the mixture B in parts by weight to obtain the artificial soil. 2-4 parts of the mixture A, 1-3 parts of fly ash, 0.2-2 parts of desulfurized gypsum, 0.02 part of zeolite powder, 0.01-1 part of an ecological mineral nutrient modifier and 0.01-0.05 part of an ecological nutrient rejuvenation agent are mixed, d, synthesis is conducted, after a high-speed blade crusher is used for scattering, a blowing-away machine is used for blowing away, and the artificial soil is obtained. The problem that in the prior art, solid waste and an added modifier are difficult to evenly mix, and consequently part of areas are not suitable for crop growth is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste treatment, and in particular to a method for synthesizing artificial soil by utilizing solid waste. Background Art

[0002] With the acceleration of my country's industrialization and urbanization, various solid wastes are generated in large quantities, such as a large amount of industrial waste slag generated in industrial production activities. These waste slags contain various heavy metals, harmful substances and substances that are difficult to degrade naturally. At the same time, due to the high density of urban population, the amount of urban domestic waste is increasing, and the difficulty of treatment is also increasing.

[0003] The traditional methods of solid waste treatment are landfill and incineration. Although the landfill method is simple and easy to implement, it has many disadvantages. For example, landfills will occupy a large amount of valuable land resources, and the landfilled garbage has not been harmlessly treated, leaving a large number of bacteria and viruses, and there are hidden dangers such as methane and heavy metal pollution. In addition, the leachate from the garbage will pollute groundwater resources for a long time. Although incineration treatment can reduce the volume of solid waste to a certain extent, a large amount of harmful gases and particulate matter, such as carbon dioxide, sulfur dioxide, fly ash, etc., will be released during the incineration process. If there are no supporting treatment facilities, it will cause secondary pollution to the environment and harm human health. These traditional treatment methods are not only costly, but also have unavoidable negative impacts on the environment.

[0004] However, in the agricultural field and ecological environment restoration projects, the demand for soil resources is very urgent. High-quality soil is the basis for crop growth. However, due to long-term irrational development and utilization, soil erosion, pollution and other factors, natural high-quality soil resources have gradually decreased, leading to land degradation, limited crop yields and ecosystem imbalance. Problems have become increasingly prominent. However, some solid wastes themselves contain nutrients similar to natural soils. For example, river silt is rich in organic matter, nitrogen, phosphorus, potassium and other nutrients, as well as humus colloids, which can not only enhance soil fertility and promote plant growth, but also improve soil structure, improve soil permeability and water retention capacity. Therefore, the use of solid waste to synthesize artificial soil has become a key research direction. However, the current synthetic artificial soil only solves the physical properties of soil such as soil aggregates, and does not make up for the soil nutrients.

[0005] Moreover, in the process of synthesizing artificial soil using solid waste, some amendments need to be added at the start-up. If the amendments are not evenly mixed in the solid waste, the areas where the amendments are not mixed will form "invalid areas", resulting in most heavy metals or organic pollutants not being fully fixed and migrating to groundwater with rainwater leaching, thereby causing pollution, soil degradation, and uneven distribution of soil nutrients.

[0006] Based on this, the present invention aims to use solid waste to synthesize an artificial soil, which complements the soil organic nutrients, mineral nutrients and microbial environment to form a complete soil ecological environment, which is beneficial to crop growth. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a method for synthesizing artificial soil using solid waste to solve the problem in the prior art mentioned in the background technology that it is difficult to evenly mix the solid waste with the added improver, resulting in the properties of some areas being unsuitable for crop growth.

[0008] To achieve the above object, the present invention provides the following technical solutions: A method for synthesizing artificial soil using solid waste comprises the following steps: (a) Initial mixing: according to weight, 1-3 parts of river sludge, 1-2 parts of fly ash, 1-2 parts of livestock manure, 0.2-0.4 parts of zeolite powder, and 0.1-0.2 parts of fermentation agent are mixed using solid waste mixing equipment; (b), fermentation, film covering and high temperature aerobic fermentation to obtain a mixture A; (c) Mixing: According to weight, 2-4 parts of mixture A are mixed with 1-3 parts of fly ash, 0.2-2 parts of desulfurized gypsum, 0.02 parts of zeolite powder, 0.01-1 parts of ecological mineral nutrient modifier, and 0.01-0.05 parts of ecological nutrient rejuvenation agent; (d) Synthesis: After breaking up with a high-speed blade crusher, the artificial soil is obtained by blowing it with a blower.

[0009] On the basis of the above scheme, in step (a), the solid waste mixing equipment includes a mobile trolley, a carrying frame is installed on the top of the mobile trolley, and further includes: Quantitative boxes, a plurality of quantitative boxes are fixedly installed at equal distances on both sides of the interior of the carrying frame; A discharge cylinder, the bottom of each quantitative box is connected to the discharge cylinder, and the discharge cylinder is fixedly connected to the supporting frame; A closed frame, wherein the closed frames are fixedly mounted on both sides of each of the discharge barrels, and the two closed frames on each of the discharge barrels are symmetrically arranged; A closing plate, wherein the closing plate is slidably mounted inside each of the closing frames, and the ends of the closing plates in every two symmetrically arranged closing frames are adapted; A first electric cylinder, each of the closing frames is fixedly mounted with the first electric cylinder, and an output end of the first electric cylinder is fixedly connected to the closing plate; A homogenizing component is installed inside each of the quantitative boxes to stir the substance to be added; A stirring and mixing assembly, which is installed at the bottom of the supporting frame and is used to mix the added substances and solid waste; A material mixing and stirring assembly is installed at the bottom of the supporting frame and is used for mixing solid waste.

[0010] On the basis of the above scheme, the homogenizing component comprises: A stirring rod, wherein each of the quantitative boxes is rotatably mounted with the stirring rod; Arc rods, each stirring rod is provided with a plurality of arc rods fixedly mounted at equal angles in a circular shape; Driving rods, two driving rods are symmetrically and rotatably mounted inside the supporting frame; A first motor, two of which are symmetrically and fixedly installed inside the supporting frame, and an output end of the first motor is fixedly connected to the driving rod; First bevel gears, a plurality of first bevel gears are fixedly mounted on the two driving rods at equal distances; The second bevel gear is meshed with each of the first bevel gears, and the plurality of the second bevel gears correspond to the plurality of the stirring rods one by one, and the second bevel gears are fixedly connected to the stirring rods.

[0011] On the basis of the above scheme, the stirring and mixing assembly comprises: Support frames, two of which are symmetrically and fixedly mounted on the bottom of the supporting frame; A stirring drum is rotatably mounted between the two support frames; Blades, the stirring drum is provided with a plurality of groups of blades which are rotatably mounted in a circle at equal angles, and each group of blades has a plurality of blades arranged at equal distances; A stirring rack, wherein a plurality of groups of stirring racks are installed on the stirring drum so as to rotate in a circle with the axis of the stirring drum as the center at equal angles, the plurality of groups of stirring racks and the plurality of groups of blades are staggered with each other, a plurality of stirring racks are arranged in each group at equal distances along the axis direction of the stirring drum, and every two adjacent stirring racks are staggered; A spiral plate, the spiral plates are rotatably mounted on the two support frames, and the two spiral plates are symmetrically arranged; A flexible brush, the outer ends of the two spiral plates are fixedly mounted with the flexible brush; A driving unit is installed inside the supporting frame and is used to drive the mixing drum to rotate.

[0012] On the basis of the above scheme, the driving unit comprises: A connecting shaft, the connecting shaft being rotatably mounted inside the supporting frame; A second motor, wherein the second motor is fixedly mounted inside the supporting frame, and an output end of the second motor is fixedly connected to the connecting shaft; A driven sprocket, wherein the driven sprocket is rotatably mounted inside the two support frames, and the driven sprocket is fixedly connected to the mixing drum and the spiral plate respectively; A driving sprocket, two of which are fixedly mounted on the connecting shaft; A chain is installed between the two driving sprockets and the two driven sprockets in meshing engagement.

[0013] On the basis of the above scheme, the material mixing assembly comprises: A position adjustment rack, the position adjustment rack being slidably mounted on one side of the bottom of the bearing rack; Hydraulic cylinders, two of which are symmetrically and fixedly installed inside the carrying frame, and the output ends of the hydraulic cylinders are fixedly connected to the positioning frame; A stirring cage, wherein a plurality of the stirring cages are rotatably mounted at equal distances at the bottom of the positioning frame; An arc-shaped shovel rack, wherein the bottom of each mixing cage is eccentrically fixedly provided with the arc-shaped shovel rack; A driving part is installed inside the positioning frame and is used to drive the stirring cage to rotate.

[0014] On the basis of the above scheme, the driving part includes: A driving shaft, the driving shaft is rotatably mounted inside the positioning frame; A third motor, the third motor is fixedly mounted inside the positioning frame, and an output end of the third motor is fixedly connected to the driving shaft; A third bevel gear, the third bevel gear is fixedly mounted on the upper part of each mixing cage; A fourth helical gear, a plurality of the fourth helical gears are fixedly mounted on the driving shaft at equal distances, the plurality of the fourth helical gears correspond one-to-one to the plurality of the third helical gears, and the third helical gears are meshed with the fourth helical gears.

[0015] On the basis of the above scheme, in step (a), the fermentation agent is molasses, starch, fish protein, urea and whole milk powder, and the mass ratio thereof is 20:5:1:2.5:0.5; in step (b), the high temperature aerobic fermentation temperature is 65-70°C, and the time is 7-10 days.

[0016] On the basis of the above scheme, in step (c), the preparation method of the ecological mineral nutrient modifier is carried out in the following steps in sequence: S1. According to weight proportions, 40-60 parts of potassium-rich slate, 7-9 parts of potassium feldspar, 1-2 parts of dolomite, 15-30 parts of serpentine, 15-30 parts of limestone and 10-12 parts of potassium silicate are mixed uniformly; S2. Place the materials mixed in step S1 in a muffle furnace, heat the temperature from room temperature to 1000°C at a heating rate of 1°C / min and keep it warm for 20 minutes, then heat the temperature from 1000°C to 1250°C at the same heating rate and keep it warm for 40 minutes, then quickly cool it to room temperature by air to obtain an ecological mineral nutrient modifier.

[0017] Based on the above scheme, in step (c), the ecological nutrient rejuvenation agent is earthworm protein, Bacillus subtilis, Bacillus gelatinus and Bacillus polymyxa, and their mass ratio is (0.3-5): (0.1-2): (0.1-2): (0.1-2).

[0018] The pH value of the artificial synthetic soil in the present invention is between 6.9 and 8.7, which is neutral to weakly alkaline. The pH value can effectively enhance soil fertility and is suitable for the growth of most plants. The total amount of aggregates larger than 0.25 mm in the artificial synthetic soil is between 33.1% and 50.2%, indicating that the artificial synthetic soil has a relatively loose and porous structure, and has good stability and water and fertilizer retention capabilities, which is beneficial to the growth and development of plants.

[0019] The present invention combines river sludge, fly ash and ecological mineral nutrient modifiers, utilizes small molecular organic acids in organic matter after river sludge is decomposed and organic acids secreted by the rhizosphere after crops are planted in artificial soil to promote the transformation of crystalline minerals into weakly crystalline minerals, so that silicon, aluminum, carbon and iron in the mineral materials react to form an organic and inorganic mixed colloid-balanced buffer soil colloid that is the same as that in natural soil. The colloid is mainly composed of crystalline layered silicate clay, amorphous layered silicate clay and non-silicate clay, aromatic carbon, aliphatic carbon and oxygen-containing functional groups, has a large specific surface area and reaction activity, and absorbs cations in the soil solution through permanent negative charges generated by aluminum replacement of silicon-oxygen tetrahedrons in mineral clay and variable negative charges generated by dissociation of hydrogen ions in organic matter, thereby helping plants absorb nitrogen, reducing nutrient loss, balancing nutrition and improving the fertilizer retention capacity of artificial synthetic soil.

[0020] Compared with the prior art, the present invention provides a method for synthesizing artificial soil using solid waste, which has the following beneficial effects: 1. In the present invention, the first electric cylinders on both sides of each discharge barrel are started at the same time, and the first electric cylinders drive the closing plate to move, so that a gap is generated between the two closing plates in the discharge barrel. By controlling the telescopic distance of the first electric cylinder, the width of the gap between the two closing plates can be controlled, thereby controlling the discharge speed, and the uniformity when adding zeolite powder and leavening agent, as well as the subsequent addition of desulfurized gypsum, zeolite powder, ecological mineral nutrient modifier and ecological nutrient rejuvenation agent, is convenient for mixing with solid waste, thereby improving the uniformity and reaction efficiency of the mixture and ensuring the stability of the quality of the artificial soil; 2. In the present invention, the turning and mixing drum drives the multiple blades and the turning and mixing frame to rotate at the same time, and the outer sides of the two spiral plates can contact the side walls of the fermentation tank through the setting of flexible brushes, so as to scrape and stir the materials on the side walls of the fermentation tank, and bring the materials on the outer sides back to the position of the turning and mixing drum, thereby further improving the mixing efficiency; 3. In the present invention, the material in the quantitative box is stirred by setting the homogenizing component to avoid uneven addition of the components, thereby affecting the uniformity of mixing. By setting the stirring and mixing component and the material mixing component, the stirring cage is used for circumferential stirring, and the blade and the stirring rack are used for tangential stirring. At the same time, the materials on the bottom and side walls of the fermentation tank can also be mixed, thereby ensuring that the components are evenly distributed during the mixing process. 4. The synthesis process of the present invention is simple, low-carbon and efficient, and can digest a large amount of general solid waste, reduce the pressure on the environment caused by solid waste landfill or stacking, and increase the amount of soil; and the synthetic artificial soil can contain nutrients for a long time like fertile natural soil without crops absorbing nutrients, and can meet the national 3-4 grade arable land standards, suitable for plant planting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of this application; Figure 2 It is a schematic diagram of a three-dimensional structure in section from another angle in the present application; Figure 3 This is a cross-sectional structural diagram of the homogenizing component, the stirring and mixing component and the material mixing component of the present application; Figure 4 This is a schematic cross-sectional view of the structure of the homogenizing component and the stirring and mixing component of the present application; Figure 5 It is a schematic diagram of the structure of the mean value component in this application; Figure 6 It is a schematic diagram of the cross-sectional structure of the homogenizing component in this application; Figure 7 It is a schematic cross-sectional view of the stirring and mixing assembly in this application; Figure 8It is a cross-sectional structural diagram of the stirring and mixing component and the driving part in this application; Fig. 9 It is a schematic diagram of the cross-sectional structure of the material mixing assembly in this application.

[0022] In the figure: 1. mobile trolley; 2. carrying frame; 3. quantitative box; 4. discharge cylinder; 5. closing frame; 6. closing plate; 7. first electric cylinder; 8. stirring rod; 9. arc rod; 10. driving rod; 11. first motor; 12. first bevel gear; 13. second bevel gear; 14. support frame; 15. turning cylinder; 16. blade; 17. turning frame; 18. spiral plate; 19. flexible brush; 20. connecting shaft; 21. second motor; 22. driven sprocket; 23. driving sprocket; 24. chain; 25. adjustment frame; 26. hydraulic cylinder; 27. stirring cage; 28. arc shovel frame; 29. ​​driving shaft; 30. third motor; 31. third bevel gear; 32. fourth bevel gear; 33. fermentation tank. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in this industry. Potassium-rich slate is purchased from Bayan Obo Iron Mine, dolomite is purchased from Jiaozuo Hongshi Environmental Protection Technology Co., Ltd., serpentine is purchased from Lingshou County Baifeng Mineral Products Processing Plant, albite is purchased from Lingshou County Qingling Mineral Processing Plant, and limestone is purchased from Inner Mongolia Yanhui Limestone Co., Ltd.

[0025] The methods in the following embodiments, unless otherwise specified, are conventional methods in the art.

[0026] Example 1: This example uses solid waste to synthesize an artificial soil, and its preparation process and steps are as follows: (a), initial mixing, 1kg of river sludge (sludge from Kunlun Reservoir in Baotou City), 1kg of fly ash, 1kg of livestock manure, 0.2kg of zeolite powder, 0.1kg of fermentation agent (composed of 20kg of molasses, 5kg of starch, 1kg of fish protein, 2.5kg of urea and 0.5kg of whole milk powder) were mixed evenly by using solid waste mixing equipment; (b), fermentation, film-covering and high-temperature aerobic fermentation at 65°C for 7 days to obtain a mixture A; (c) Mixing: 2 kg of mixture A, 1 kg of fly ash, 0.2 kg of desulfurized gypsum, 0.02 kg of zeolite powder, 0.01 kg of ecological mineral nutrient modifier (preparation method: 40 kg of potassium-rich slate, 7 kg of potassium feldspar, 1 kg of dolomite, 15 kg of serpentine, 15 kg of limestone and 10 kg of potassium silicate are mixed evenly and placed in a muffle furnace, and the temperature is increased from room temperature to 1000°C at a heating rate of 1°C / min and kept warm for 20 min, and then the temperature is increased from 1000°C to 1250°C at the same heating rate and kept warm for 40 min, and then quickly cooled to room temperature by air), and 0.01 kg of ecological nutrient rejuvenation agent (composed of 0.3 kg of earthworm protein and 0.1 kg of Bacillus subtilis, 0.1 kg of Bacillus jelly-like, and 0.1 kg of Bacillus polymyxa cultured in the Alxa Desert); (d) Synthesis: After breaking up with a high-speed blade crusher, the artificial soil is obtained by blowing it with a blower.

[0027] The nutrient values ​​of the artificial soil synthesized in this embodiment were measured, and the specific results are shown in the following table:

[0028] According to the classification of soil fertility in the second land survey in my country, the artificial soil synthesized in this embodiment has a soil grade between 3 and 4, which has reached the soil standard for planting crops. The specific classification standards are shown in the following table:

[0029] In order to verify the physical structure, soil fertility and effect on plant growth of the synthetic artificial soil of this embodiment, a germination toxicity test, a lettuce planting test and a shrub planting test were conducted on the soil. The specific test process is as follows: 1. Germination toxicity test Test method: Shannong 48 wheat seeds were soaked in water to remove floating wheat seeds and bad seeds. After soaking for 12 hours, they were divided into 2 groups, each with 50 seeds, and planted in the control soil of the cultivated land in Bayan Obo, Baotou and the artificial synthetic soil synthesized by the present invention respectively. After 7 days of indoor growth, the germination index was calculated by the following formula:

[0030] The test results are shown in the following table:

[0031] 2. Lettuce Planting Experiment Experimental method: This experiment adopted the direct seeding method, selected green cauliflower seeds, and converted the actual sowing amount per pot according to the sowing amount of 500g per mu. The experiment was divided into three groups, with 3 pots in each group. The field soil of Baotou Bayan Obo and the greenhouse soil of Baotou Bayan Obo were used as the control group soil, and the artificial synthetic soil was used as the experimental group soil. Before sowing, base fertilizer was applied and bottom water was irrigated thoroughly. When the seedlings grew to 4 leaves and 1 heart, thinning and transplanting were carried out. The growth of green cauliflower was observed regularly, and watering was carried out reasonably according to weather conditions and plant growth needs. No topdressing was done, and the growth situation was measured.

[0032] After 110 days of planting and growth, samples of green stalked cabbage were collected daily to determine their biomass. Fresh plants were collected, the above-ground and underground parts were separated, rinsed with clean water, and blown dry to determine the fresh weight of the plants. The plants were then placed in a 65°C oven to dry to constant weight, and the dry weight of the plants was determined. The specific data is shown in the following table:

[0033] No top dressing was performed in this experiment. Instead, a growth test was conducted on the effect of green cabbage on nutrients in the soil. The amount of biomass showed that the nutrients in the greenhouse control soil were > those in the artificial synthetic soil > those in the field control soil.

[0034] (III) Shrub planting experiment This experiment adopted the method of planting seabuckthorn shrubs in the field directly in the test site. The test was divided into two areas. The field soil in Bayan Obo, Baotou was selected as the control soil and the artificial synthetic soil was selected as the test soil. After 12 months of growth, the tree height and breast diameter were recorded regularly. The specific results are shown in the following table:

[0035] From the test results in the above table, it can be seen that the number of branches, height and survival rate of sea buckthorn shrubs planted in the test soil are higher than those in the control soil, indicating that artificial synthetic soil can greatly increase biomass and promote rapid plant growth.

[0036] Example 2: This example uses solid waste to synthesize an artificial soil, and its preparation process and steps are as follows: (a) Preliminary mixing: 2 kg of river sludge (sludge from Kunlun Reservoir in Baotou City), 1.5 kg of fly ash, 1.5 kg of livestock manure, 0.3 kg of zeolite powder, and 0.15 kg of fermentation agent (composed of 20 kg of molasses, 5 kg of starch, 1 kg of fish protein, 2.5 kg of urea and 0.5 kg of whole milk powder) were mixed evenly; (b), fermentation, film-covering and high-temperature aerobic fermentation at 68°C for 8 days to obtain a mixture A; (c), mixing, mixing 3kg of mixture A with 2kg of fly ash, 1kg of desulfurized gypsum, 0.02kg of zeolite powder, 0.5kg of ecological mineral nutrient modifier (preparation method: 50kg of potassium-rich slate, 8kg of potassium feldspar, 1.5kg of dolomite, 20kg of serpentine, 20kg of limestone and 11kg of potassium silicate are mixed evenly and placed in a muffle furnace, and the temperature is increased from room temperature to 1000℃ at a heating rate of 1℃ / min and kept for 20min, and then the temperature is increased from 1000℃ to 1250℃ at the same heating rate and kept for 40min, and then quickly cooled to room temperature by air), and 0.03kg of ecological nutrient rejuvenation agent (composed of 4kg of earthworm protein and 1kg of Bacillus subtilis, 1kg of Bacillus jelly-like and 1kg of Bacillus polymyxa cultivated in the Alxa Desert); (d) Synthesis: After breaking up with a high-speed blade crusher, it is blown away with a blower to obtain artificial synthetic soil.

[0037] The artificial soil synthesized in this embodiment can contain nutrients for a long time without loss when no crops absorb nutrients, and is suitable for plant planting. Since the performance of the artificial soil finally obtained is almost the same when any specific value in the range of the technical solution of the present invention is used in the industrial preparation process of the synthetic artificial soil, the soil performance of the artificial soil synthesized in this embodiment is the same as that in Example 1, and the performance test is not performed separately here.

[0038] Example 3: This example uses solid waste to synthesize an artificial soil, and its preparation process and steps are as follows: (a) Preliminary mixing: 3 kg of river sludge (sludge from Kunlun Reservoir in Baotou City), 2 kg of fly ash, 2 kg of livestock manure, 0.4 kg of zeolite powder, and 0.2 kg of fermentation agent (composed of 20 kg of molasses, 5 kg of starch, 1 kg of fish protein, 2.5 kg of urea and 0.5 kg of whole milk powder) were mixed evenly; (b), fermentation, covering with film and conducting high temperature aerobic fermentation at 70°C for 10 days to obtain a mixture A; (c) Mixing: 4 kg of mixture A, 3 kg of fly ash, 2 kg of desulfurized gypsum, 0.02 kg of zeolite powder, 1 kg of ecological mineral nutrient modifier (preparation method: 60 kg of potassium-rich slate, 9 kg of potassium feldspar, 2 kg of dolomite, 30 kg of serpentine, 30 kg of limestone and 12 kg of potassium silicate are mixed evenly and placed in a muffle furnace, and the temperature is increased from room temperature to 1000°C at a heating rate of 1°C / min and kept warm for 20 min, and then the temperature is increased from 1000°C to 1250°C at the same heating rate and kept warm for 40 min, and then quickly cooled to room temperature by air), and 0.05 kg of ecological nutrient rejuvenation agent (composed of 5 kg of earthworm protein and 2 kg of Bacillus subtilis, 2 kg of Bacillus jelly-like and 2 kg of Bacillus polymyxa cultured in the Alxa Desert); (d) Synthesis: After breaking up with a high-speed blade crusher, the artificial soil is obtained by blowing it with a blower.

[0039] The artificial soil synthesized in this embodiment can contain nutrients for a long time without loss when no crops absorb nutrients, and is suitable for plant planting. Since the performance of the artificial soil finally obtained is almost the same when any specific value in the range of the technical solution of the present invention is used in the industrial preparation process of the synthetic artificial soil, the soil performance of the artificial soil synthesized in this embodiment is the same as that in Example 1, and the performance test is not performed separately here.

[0040] Embodiment 4, according to the above-mentioned method for synthesizing artificial soil using solid waste, in step (a), the solid waste mixing equipment includes a mobile trolley 1, a carrying frame 2 is installed on the top of the mobile trolley 1, and also includes a quantitative box 3, a discharge barrel 4, a closing frame 5, a closing plate 6, a first electric cylinder 7, a homogenizing component, a turning and mixing component and a material mixing component, a plurality of quantitative boxes 3 are fixedly installed at equal distances on both sides of the inside of the carrying frame 2, each quantitative box 3 is connected to a discharge barrel 4 at the bottom, the discharge barrel 4 is fixedly connected to the carrying frame 2, and a closing frame 5 is fixedly installed on both sides of each discharge barrel 4, and the two closing frames 5 on each discharge barrel 4 are symmetrically arranged, and a closing plate 6 is slidably installed inside each closing frame 5, and the ends of the closing plates 6 in each two symmetrically arranged closing frames 5 are adapted, and a first electric cylinder 7 is fixedly installed on each closing frame 5, and the output end of the first electric cylinder 7 is connected to the closing The clamping plate 6 is fixedly connected, and a homogenizing component is installed inside each quantitative box 3 for stirring the substance to be added. The homogenizing component includes a stirring rod 8, an arc rod 9, a driving rod 10, a first motor 11, a first bevel gear 12 and a second bevel gear 13. A stirring rod 8 is rotatably installed inside each quantitative box 3, and each stirring rod 8 is fixedly installed with multiple arc rods 9 at equal angles in a circular shape. Two driving rods 10 are symmetrically and rotatably installed inside the supporting frame 2, and two first motors 11 are symmetrically and fixedly installed inside the supporting frame 2. The output end of the first motor 11 is fixedly connected to the driving rod 10, and multiple first bevel gears 12 are fixedly installed on the two driving rods 10 at equal distances. Each first bevel gear 12 is meshed with a second bevel gear 13, and the multiple second bevel gears 13 correspond to the multiple stirring rods 8 one by one, and the second bevel gear 13 is fixedly connected to the stirring rod 8.

[0041] Specifically, when solid waste is used to form artificial soil, it is necessary to first mix river silt, fly ash and livestock manure together and pour them into the fermentation tank 33, and then add the required zeolite powder and leavening agent into the corresponding quantitative box 3. Since the quantitative box 3 is provided with two rows, each row is provided with a plurality of quantitative boxes 3. In the process of adding zeolite powder and leavening agent, the specific weight of zeolite powder and leavening agent is first determined, and then the zeolite powder and leavening agent are divided into multiple portions of the same weight according to their weight, and then the corresponding weights of zeolite powder and leavening agent are put into the plurality of quantitative boxes 3 in the order of each row, that is, the mass of the mixture of zeolite powder and leavening agent contained in each quantitative box 3 is the same, and then the mobile trolley 1 is started to drive the carrying frame 2 to move until the material mixing assembly enters the fermentation tank 33. At this time, the material mixing assembly is started to mix the river silt, fly ash and livestock manure together. The mixture is stirred, and the turning and mixing component is started to mix the materials stirred by the material mixing component. At the same time, the first electric cylinders 7 on both sides of each discharge barrel 4 are started, and the first electric cylinders 7 drive the closing plate 6 to move until the closing plate 6 enters the closing frame 5, so that a gap is generated between the two closing plates 6 in the discharge barrel 4, so that the mixture of zeolite powder and leavening agent is discharged. By controlling the telescopic distance of the first electric cylinder 7, the gap width between the two closing plates 6 can be controlled, thereby controlling the discharge speed. At the same time, the first motor 11 is started, and the first motor 11 drives the driving rod 10 to rotate, and the driving rod 10 drives the first bevel gear 12 to rotate. Through the engagement of the first bevel gear 12 and the second bevel gear 13, multiple stirring rods 8 can be driven to rotate synchronously. Through the setting of the arc rod 9, the mixture of zeolite powder and leavening agent in the quantitative box 3 is mixed to ensure uniformity.

[0042] After the river silt, fly ash, livestock and poultry manure and other materials are mixed with zeolite powder and fermentation agent, the mobile trolley 1 is removed, the fermentation tank 33 is coated with a film, and high-temperature aerobic fermentation is carried out. After the fermentation is completed, a mixture A is obtained, and then fly ash in a corresponding proportion is evenly added to the fermentation tank 33, and then desulfurized gypsum, zeolite powder, ecological mineral nutrient modifier and ecological nutrient rejuvenation agent are mixed together in proportion, and evenly placed in multiple quantitative boxes 3 in the above manner, and then the above steps are repeated to mix the mixture A, fly ash and other added materials. After mixing evenly, it is sent to a high-speed blade crusher and blown away with a blower to obtain artificial soil.

[0043] It should be added that when controlling the discharge speed, it is necessary to calculate in combination with the length of the fermentation tank 33, and finally discharge the material from the entrance of the fermentation tank 33, and after stirring, the material is just discharged when the mobile trolley 1 brings the supporting frame 2 to the innermost part of the fermentation tank 33, so as to make the discharge more uniform.

[0044] The stirring and mixing assembly is installed at the bottom of the supporting frame 2, and is used to mix the added substances and solid waste. The stirring and mixing assembly includes a support frame 14, a stirring drum 15, a blade 16, a stirring frame 17, a spiral plate 18, a flexible brush 19 and a driving part. Two support frames 14 are symmetrically and fixedly installed at the bottom of the supporting frame 2. A stirring drum 15 is rotatably installed between the two support frames 14. Multiple groups of blades 16 are rotatably installed on the stirring drum 15 at equal angles in a circular shape. Each group of blades 16 is arranged at equal distances. The stirring drum 15 is provided with a plurality of blades 16 at equal distances. The axis of the drum 15 is the center and multiple groups of turning frames 17 are installed in a circular shape with equal angles. The multiple groups of turning frames 17 and the multiple groups of blades 16 are staggered with each other. Each group of turning frames 17 is arranged at equal distances along the axis direction of the turning drum 15, and every two adjacent turning frames 17 are staggered. Spiral plates 18 are rotatably installed on the two support frames 14, and the two spiral plates 18 are symmetrically arranged. Flexible brushes 19 are fixedly installed on the outer ends of the two spiral plates 18. The driving part is installed inside the carrying frame 2 to drive the turning drum 15 to rotate.

[0045] Specifically, when the mixture of river sludge, fly ash and livestock manure is further mixed and zeolite powder and leavening agent are evenly added thereto, the driving unit is started, and the driving unit drives the stirring drum 15 to rotate, and the stirring drum 15 drives the plurality of blades 16 and the stirring frame 17 to rotate at the same time, and the driving unit drives the spiral plate 18 to rotate, and the outer sides of the two spiral plates 18 are at a certain distance from the side wall of the fermentation tank 33. Through the setting of the flexible brush 19, the flexible brush 19 can contact the side wall of the fermentation tank 33, thereby scraping and stirring the material on the side wall of the fermentation tank 33, The setting of the spiral plate 18 can bring the outer materials back to the position of the stirring drum 15, further improving the mixing efficiency. Through the setting of the blade 16, the river silt, fly ash and livestock manure are turned over, and at the same time, the stirring frame 17 will throw up part of the mixture, thereby further improving the stirring efficiency. When it reaches the innermost part of the fermentation tank 33, the reverse driving part drives the stirring drum 15 to rotate in the opposite direction, and then moves back through the setting of the mobile trolley 1 to further stir it. If the stirring is not uniform in one time, the above steps can be repeated to stir it again.

[0046] As mentioned above, the driving part includes a connecting shaft 20, a second motor 21, a driven sprocket 22, a driving sprocket 23 and a chain 24. The connecting shaft 20 is rotatably installed inside the supporting frame 2, the second motor 21 is fixedly installed inside the supporting frame 2, and the output end of the second motor 21 is fixedly connected to the connecting shaft 20. The two support frames 14 are both rotatably installed with driven sprockets 22, and the driven sprockets 22 are respectively fixedly connected to the mixing drum 15 and the spiral plate 18. Two driving sprockets 23 are fixedly installed on the connecting shaft 20, and chains 24 are meshed between the two driving sprockets 23 and the two driven sprockets 22.

[0047] Specifically, when driving the mixing drum 15 to rotate, the second motor 21 is started, and the second motor 21 drives the connection to rotate, thereby driving the driving sprocket 23 to rotate. The driving sprocket 23 drives the driven sprocket 22 to rotate through the setting of the chain 24, and can drive the mixing drum 15 and the spiral plate 18 to rotate.

[0048] The material mixing assembly is installed at the bottom of the supporting frame 2, and is used to mix the solid waste. The material mixing assembly includes a positioning frame 25, a hydraulic cylinder 26, a mixing cage 27, an arc-shaped shovel frame 28 and a driving part. The positioning frame 25 is slidably installed on one side of the bottom of the supporting frame 2, and two hydraulic cylinders 26 are symmetrically and fixedly installed inside the supporting frame 2. The output ends of the hydraulic cylinders 26 are fixedly connected to the positioning frame 25. A plurality of mixing cages 27 are rotatably installed at equal distances at the bottom of the positioning frame 25. An arc-shaped shovel frame 28 is eccentrically fixedly installed at the bottom of each mixing cage 27. The driving part is installed inside the positioning frame 25, and is used to drive the mixing cage 27 to rotate.

[0049] Specifically, when it is necessary to mix river sludge, fly ash and livestock manure, the hydraulic cylinder 26 is first started, and the hydraulic cylinder 26 drives the adjustment frame 25 to move until the arc-shaped shovel frame 28 at the bottom of the stirring cage 27 is driven to contact the bottom of the fermentation tank 33. At this time, the driving part is started, and the driving part drives multiple stirring cages 27 to rotate, and at the same time drives multiple arc-shaped shovel frames 28 to rotate. Through the setting of the stirring cage 27, the river sludge, fly ash and livestock manure are mixed. Through the setting of the arc-shaped shovel frame 28, the river sludge, fly ash and livestock manure at the bottom of the fermentation tank 33 are mixed, thereby improving the uniformity of the mixing.

[0050] As mentioned above, the driving part includes a driving shaft 29, a third motor 30, a third bevel gear 31 and a fourth bevel gear 32. The driving shaft 29 is rotatably installed inside the positioning frame 25, and the third motor 30 is fixedly installed inside the positioning frame 25. The output end of the third motor 30 is fixedly connected to the driving shaft 29. A third bevel gear 31 is fixedly installed on the upper part of each stirring cage 27, and a plurality of fourth bevel gears 32 are fixedly installed on the driving shaft 29 at equal distances. The plurality of fourth bevel gears 32 correspond to the plurality of third bevel gears 31 one by one, and the third bevel gear 31 is meshed with the fourth bevel gear 32.

[0051] Specifically, when it is necessary to drive multiple stirring cages 27 to rotate, start the third motor 30, the third motor 30 drives the driving shaft 29 to rotate, the driving shaft 29 drives multiple fourth bevel gears 32 to rotate, the fourth bevel gears 32 are meshed with the third bevel gears 31, and the stirring cages 27 can be driven to rotate through the third bevel gears 31 to perform stirring and achieve efficient mixing.

[0052] The working principle or usage process of this application is as follows: When solid waste is used to form artificial soil, it is necessary to first mix river silt, fly ash and livestock manure together and pour them into the fermentation tank 33, and then add the required zeolite powder and leavening agent into the corresponding quantitative box 3. Since the quantitative boxes 3 are arranged in two rows, each row is provided with multiple quantitative boxes 3. In the process of adding zeolite powder and leavening agent, first determine the specific weight of the zeolite powder and the leavening agent, and then divide them into multiple portions of equal weight according to their weight, and then put the zeolite powder and leavening agent of corresponding weight in the order of the multiple quantitative boxes 3 in each row, that is, the mass of the mixture of zeolite powder and leavening agent contained in each quantitative box 3 is the same, and then start the mobile trolley 1 to drive the supporting frame 2 to move until the stirring cage 27 enters the fermentation tank 33.

[0053] When it is necessary to mix river sludge, fly ash and livestock excrement, the hydraulic cylinder 26 is first started, and the hydraulic cylinder 26 drives the adjustment frame 25 to move until the arc-shaped shovel frame 28 at the bottom of the stirring cage 27 is driven to contact the bottom of the fermentation tank 33. At this time, the third motor 30 is started, and the third motor 30 drives the driving shaft 29 to rotate, and the driving shaft 29 drives multiple fourth bevel gears 32 to rotate. The fourth bevel gear 32 is meshed with the third bevel gear 31, and the stirring cage 27 can be driven to rotate through the third bevel gear 31. When the stirring cage 27 rotates, it will also drive multiple arc-shaped shovel frames 28 to rotate. Through the setting of the stirring cage 27, river sludge, fly ash and livestock excrement are mixed. Through the setting of the arc-shaped shovel frame 28, the river sludge, fly ash and livestock excrement at the bottom of the fermentation tank 33 are mixed circumferentially, thereby improving the uniformity of the mixing.

[0054] At the same time, the second motor 21 is started, and the second motor 21 drives the connection to rotate, thereby driving the active sprocket 23 to rotate. The active sprocket 23 drives the driven sprocket 22 to rotate through the setting of the chain 24, which can drive the turning drum 15 and the spiral plate 18 to rotate. The turning drum 15 simultaneously drives multiple blades 16 and the turning frame 17 to rotate, and the driving unit drives the spiral plate 18 to rotate. The outer sides of the two spiral plates 18 are at a certain distance from the side wall of the fermentation tank 33. Through the setting of the flexible brush 19, the flexible brush 19 can contact the side wall of the fermentation tank 33, thereby scraping and stirring the material on the side wall of the fermentation tank 33. Through the setting of the spiral plate 18, the material on the outer side can be gathered back to the position of the turning drum 15, further improving the mixing efficiency. Through the setting of the blade 16, the river sludge, fly ash and livestock manure are turned tangentially, and the turning frame 17 will throw up part of the mixture, thereby further improving the turning efficiency.

[0055] As the mobile trolley 1 moves, the first electric cylinder 7 on both sides of each discharge barrel 4 is started simultaneously during the stirring process, and the first electric cylinder 7 drives the closing plate 6 to move until the closing plate 6 enters the closing frame 5, so that a gap is generated between the two closing plates 6 in the discharge barrel 4, so that the mixture of zeolite powder and leavening agent is discharged. By controlling the telescopic distance of the first electric cylinder 7, the gap width between the two closing plates 6 can be controlled, thereby controlling the discharge speed. At the same time, the first motor 11 is started, and the first motor 11 drives the driving rod 10 to rotate, and the driving rod 10 drives the first bevel gear 12 to rotate. Through the engagement of the first bevel gear 12 and the second bevel gear 13, multiple stirring rods 8 can be driven to rotate synchronously. Through the setting of the arc rod 9, the mixture of zeolite powder and leavening agent in the quantitative box 3 is mixed to ensure uniformity.

[0056] After the river sludge, fly ash, livestock excrement and other materials are mixed with the zeolite powder and the fermentation agent, the movable trolley 1 is removed, and the fermentation tank 33 is coated with a film to perform high-temperature aerobic fermentation. After the fermentation is completed, the mixture A can be obtained.

[0057] After the fermentation is completed, the corresponding proportion of fly ash is evenly added to the fermentation tank 33, and then the desulfurized gypsum, zeolite powder, ecological mineral nutrient modifier and ecological nutrient rejuvenation agent are mixed together in proportion, and evenly placed into multiple quantitative boxes 3 in the above manner, and then the above steps are repeated to mix the mixture A, fly ash and other added materials. After mixing evenly, it is sent to a high-speed blade crusher and blown away with a blower to obtain artificial soil.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for synthesizing artificial soil using solid waste, characterized in that: The following steps are involved: (a) Initial mixing: according to weight, 1-3 parts of river sludge, 1-2 parts of fly ash, 1-2 parts of livestock manure, 0.2-0.4 parts of zeolite powder, and 0.1-0.2 parts of fermentation agent are mixed using solid waste mixing equipment; (b), fermentation, film covering and high temperature aerobic fermentation to obtain a mixture A; (c) Mixing: According to weight, 2-4 parts of mixture A are mixed with 1-3 parts of fly ash, 0.2-2 parts of desulfurized gypsum, 0.02 parts of zeolite powder, 0.01-1 parts of ecological mineral nutrient modifier, and 0.01-0.05 parts of ecological nutrient rejuvenation agent; (d) Synthesis: After breaking up with a high-speed blade crusher, the artificial soil is obtained by blowing it with a blower.

2. The method for synthesizing artificial soil using solid waste according to claim 1, characterized in that: In step (a), the fermentation agent is molasses, starch, fish protein, urea and whole milk powder, and the mass ratio thereof is 20:5:1:2.5:0.5; in step (b), the high temperature aerobic fermentation temperature is 65-70° C., and the fermentation time is 7-10 days.

3. The method for synthesizing artificial soil using solid waste according to claim 1, characterized in that: In step (c), the preparation method of the ecological mineral nutrient modifier is carried out in the following steps in sequence: S1. According to weight proportions, 40-60 parts of potassium-rich slate, 7-9 parts of potassium feldspar, 1-2 parts of dolomite, 15-30 parts of serpentine, 15-30 parts of limestone and 10-12 parts of potassium silicate are mixed uniformly; S2. Place the materials mixed in step S1 in a muffle furnace, heat the temperature from room temperature to 1000°C at a heating rate of 1°C / min and keep it warm for 20 minutes, then heat the temperature from 1000°C to 1250°C at the same heating rate and keep it warm for 40 minutes, then cool it to room temperature by air cooling to obtain an ecological mineral nutrient modifier.

4. The method for synthesizing artificial soil using solid waste according to claim 1, characterized in that: In step (c), the ecological nutrient rejuvenation agent is earthworm protein, Bacillus subtilis, Bacillus gelatinus and Bacillus polymyxa, and the mass ratio thereof is (0.3-5): (0.1-2): (0.1-2): (0.1-2).

5. A method for synthesizing artificial soil using solid waste according to any one of claims 1 to 4, wherein in step (a), the solid waste mixing equipment comprises a mobile trolley (1), a carrying frame (2) is installed on the top of the mobile trolley (1), characterized in that: Also includes: A quantitative box (3), wherein a plurality of the quantitative boxes (3) are fixedly installed at equal distances on both sides of the interior of the supporting frame (2); A discharge barrel (4), the bottom of each quantitative box (3) is connected to the discharge barrel (4), and the discharge barrel (4) is fixedly connected to the supporting frame (2); A closed frame (5), each of the two sides of the discharge barrel (4) being fixedly mounted with the closed frame (5), and the two closed frames (5) on each of the discharge barrels (4) being symmetrically arranged; A closing plate (6), wherein the closing plate (6) is slidably mounted inside each of the closing frames (5), and the ends of the closing plates (6) in every two symmetrically arranged closing frames (5) are adapted to fit; a first electric cylinder (7), wherein each of the closing frames (5) is fixedly mounted with the first electric cylinder (7), and an output end of the first electric cylinder (7) is fixedly connected to the closing plate (6); A homogenizing component, each of the quantitative boxes (3) is equipped with the homogenizing component for stirring the substance to be added; A stirring and mixing component, which is installed at the bottom of the supporting frame (2) and is used to mix the added substances and solid waste; A material mixing and stirring component, the material mixing and stirring component is installed at the bottom of the supporting frame (2) and is used for mixing solid waste.

6. The method for synthesizing artificial soil using solid waste according to claim 5, characterized in that: The homogenizing component comprises: A stirring rod (8), wherein each of the quantitative boxes (3) is rotatably mounted with the stirring rod (8); Arc-shaped rods (9), each of the stirring rods (8) having a plurality of the arc-shaped rods (9) fixedly mounted at equal angles in a circular shape; A driving rod (10), wherein two driving rods (10) are symmetrically and rotatably mounted inside the supporting frame (2); A first motor (11), wherein two first motors (11) are symmetrically and fixedly mounted inside the supporting frame (2), and an output end of the first motor (11) is fixedly connected to the driving rod (10); First bevel gears (12), a plurality of first bevel gears (12) being fixedly mounted at equal distances on the two driving rods (10); A second bevel gear (13), each of the first bevel gears (12) being meshed with the second bevel gear (13), a plurality of the second bevel gears (13) corresponding one-to-one to a plurality of the stirring rods (8), and the second bevel gears (13) being fixedly connected to the stirring rods (8).

7. The method for synthesizing artificial soil using solid waste according to claim 6, characterized in that: The stirring and mixing assembly comprises: Support frames (14), two of the support frames (14) being symmetrically and fixedly mounted on the bottom of the supporting frame (2); A stirring drum (15), wherein the stirring drum (15) is rotatably mounted between the two support frames (14); Blades (16), wherein a plurality of groups of blades (16) are mounted on the stirring drum (15) in a circular manner and are rotatable at equal angles, and a plurality of blades (16) are arranged at equal distances in each group; A stirring rack (17), wherein a plurality of groups of stirring racks (17) are mounted on the stirring drum (15) so as to be rotatable at equal angles in a circle with the axis of the stirring drum (15) as the center, the plurality of groups of stirring racks (17) and the plurality of groups of blades (16) are staggered with each other, a plurality of stirring racks (17) are arranged in each group at equal distances along the axis direction of the stirring drum (15), and every two adjacent stirring racks (17) are staggered; A spiral plate (18), the spiral plates (18) being rotatably mounted on the two support frames (14), and the two spiral plates (18) being symmetrically arranged; A flexible brush (19), the flexible brush (19) being fixedly mounted on the outer ends of the two spiral plates (18); A driving unit, the driving unit is installed inside the supporting frame (2) and is used to drive the stirring drum (15) to rotate.

8. The method for synthesizing artificial soil using solid waste according to claim 7, characterized in that: The driving unit comprises: A connecting shaft (20), the connecting shaft (20) being rotatably mounted inside the supporting frame (2); a second motor (21), the second motor (21) being fixedly mounted inside the supporting frame (2), and an output end of the second motor (21) being fixedly connected to the connecting shaft (20); A driven sprocket (22), wherein the driven sprocket (22) is rotatably mounted inside the two support frames (14), and the driven sprocket (22) is fixedly connected to the stirring drum (15) and the spiral plate (18) respectively; A driving sprocket (23), two of which are fixedly mounted on the connecting shaft (20); A chain (24) is installed in meshing engagement between the two driving sprockets (23) and the two driven sprockets (22).

9. The method for synthesizing artificial soil using solid waste according to claim 8, characterized in that: The material mixing assembly comprises: A positioning frame (25), the positioning frame (25) being slidably mounted on one side of the bottom of the supporting frame (2); Hydraulic cylinders (26), two of which are symmetrically and fixedly mounted inside the supporting frame (2), and output ends of the hydraulic cylinders (26) are fixedly connected to the positioning frame (25); A stirring cage (27), wherein a plurality of the stirring cages (27) are rotatably mounted at equal distances on the bottom of the positioning frame (25); An arc-shaped shovel frame (28), wherein the bottom of each mixing cage (27) is eccentrically fixedly mounted with the arc-shaped shovel frame (28); A driving part, the driving part is installed inside the positioning frame (25) and is used to drive the stirring cage (27) to rotate.

10. The method for synthesizing artificial soil using solid waste according to claim 9, characterized in that: The driving part comprises: A driving shaft (29), the driving shaft (29) being rotatably mounted inside the positioning frame (25); a third motor (30), the third motor (30) being fixedly mounted inside the positioning frame (25), the output end of the third motor (30) being fixedly connected to the driving shaft (29); A third bevel gear (31), the third bevel gear (31) being fixedly mounted on the upper portion of each stirring cage (27); Fourth bevel gears (32), a plurality of fourth bevel gears (32) are fixedly mounted on the driving shaft (29) at equal distances, the plurality of fourth bevel gears (32) correspond one-to-one to the plurality of third bevel gears (31), and the third bevel gears (31) are meshed with the fourth bevel gears (32).

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