Production process for preparing tofu cat litter from wet bean dregs by one-step method

Abstract

The invention discloses a production process for preparing tofu cat litter from wet bean dregs by a one-step method, and belongs to the technical field of tofu cat litter production, resource recycling and environmental protection, and the production process comprises the following steps: treating the wet bean dregs through multistage filter pressing equipment with a continuous vacuum auxiliary function; homogenizing and mixing the filter-pressed wet bean dregs with a reinforcing agent, a binder and a modifier in an ultrasonic dynamic mixing device; performing low-temperature puffing on the mixed material; the production efficiency of the tofu cat litter is remarkably improved, energy consumption is reduced, low carbon and environmental protection are achieved, the processes of repeated drying and water adding are avoided, a reasonable formula and novel equipment are combined, the water absorption, deodorization and antibacterial property of the cat litter are improved, the long-term problem of the bean product industry can be solved, and the production cost is reduced. The defect of poor performance of the environment-friendly cat litter in the market can be overcome, and an innovative resource recycling technical scheme is provided.

Description

Technical Field

[0001] The present invention relates to the technical fields of tofu cat litter production, resource recycling, and environmental protection, and specifically to a production process for preparing tofu cat litter by a one-step method from wet soybean dregs. Background Art

[0002] The soy product processing industry is an important part of the Chinese food industry. Wet soybean dregs are the main by-products generated during the production of soy products such as tofu, soy milk, vermicelli, and soy protein extraction. Their output accounts for 25%-40% of the weight of the raw materials for soy product processing. The water content of wet soybean dregs is usually 60%-95%, and they are rich in protein and fiber, extremely prone to deterioration and emitting odors. Traditional treatment methods such as composting or using as feed have a low level of resource utilization and are prone to causing environmental pollution during the treatment process.

[0003] As an adsorption and deodorization medium for cat excrement, cat litter is an important product in the pet supplies market. Among them, tofu cat litter, made from plant fibers, is degradable, has strong water absorption, and is dust-free, and has gradually become the mainstream in the market.

[0004] Currently, the tofu cat litter on the market uses wet soybean dregs as the main raw material, and its production process is usually divided into two steps: drying of wet soybean dregs: soy product processing enterprises hand over wet soybean dregs to a third-party drying factory to reduce the water content to 5%-10%; cat litter production: the dried soybean dregs are transported to a cat litter factory, and then granulated by adding water, fillers, and binders and dried to produce finished cat litter. The main drawbacks of this process include that the drying link of wet soybean dregs consumes a large amount of natural gas or electric energy, increasing production costs and being not environmentally friendly; multi-link operations from soy product processing enterprises to drying factories and then to cat litter factories result in high logistics costs and labor costs, and each link requires profit, with costs increasing layer by layer; in the repeated drying and water-adding links of wet soybean dregs, the resource utilization efficiency is low and may lead to a decline in the performance of cat litter. Therefore, it is very necessary to develop a new set of production technologies and processes for preparing tofu cat litter by a one-step method from wet soybean dregs. Summary of the Invention

[0005] The purpose of the present invention is to provide a production process for preparing tofu cat litter by a one-step method from wet soybean dregs to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: A production process for preparing tofu cat litter by a one-step method from wet soybean dregs, including the following steps:

[0007] S1. Process the wet soybean dregs through a multi-stage pressure filtration device with a continuous vacuum assistance function. First, reduce the water content in the wet soybean dregs from 95% to 70% through preliminary pressure filtration, and then perform secondary high-pressure vacuum pressure filtration to further reduce the water content to 40%-50%;

[0008] S2. Homogeneously mix the pressure-filtered wet soybean dregs with an enhancer, a binder, and a modifier in an ultrasonic dynamic mixing device to generate a semi-solid mixture with stable dispersibility;

[0009] S3. Feed the above mixed materials into a high-shear screw puffing device with a temperature control feedback system for low-temperature puffing to ensure the formation of microporous structures inside the particles and smooth surfaces;

[0010] S4. Use a microwave-infrared combined drying device to control the drying process in three stages and perform multi-stage drying operations to gradually remove the bound water in the puffed particles;

[0011] S5. Spray a functional coating containing bamboo vinegar liquid, nano silver, and chitosan on the particle surface to form a long-lasting antibacterial and deodorant protection film;

[0012] S6. Screen the modified particles according to the target particle size range to ensure the uniformity and physical properties of the particles. After packaging the finished products, perform quantitative packaging through an automated packaging device.

[0013] In a further embodiment, in step S2, the enhancer includes one or more of starch, nano calcium carbonate, nano silica aerogel, diatomite, modified wood fiber powder, bentonite, halloysite, vermiculite, zeolite, white carbon black, oyster shell powder, etc. The weight ratio of the starch is 10%-30%, the weight ratio of the nano calcium carbonate is 2%-8%, the nano silica aerogel is 1%-3%, the weight ratio of the zeolite is 3%-6%, the weight ratio of the modified wood fiber powder is 3%-18%, and the weight ratio of one or more of bentonite, halloysite, vermiculite, diatomite, white carbon black, oyster shell powder, etc. is 1%-4%.

[0014] In a further embodiment, in step S2, the binder is a composite of acetylated cassava starch and a modified natural plant gum. The weight ratio of the acetylated cassava starch is 0.5%-2%, the modified natural plant gum is a composite of sulfonated lignin / polyethylene glycol condensation gum, and the weight ratio is 0.5%-1%. The mass ratio of the sulfonated lignin to the polyethylene glycol condensation gum is 0.3-0.7.

[0015] In a further embodiment, in step S2, the modifier includes a zeolite molecular sieve / nano silver complex, a nano cellulose-enhanced starch glue, and a plant extract. The weight ratio of the zeolite molecular sieve / nano silver complex is 2%-4%, the weight ratio of the nano cellulose-enhanced starch glue is 1%-5%, and the plant extract is a rosmarinic acid / cyclodextrin inclusion complex, with a weight ratio of 2%-4%.

[0016] In a further embodiment, in step S3, the high-shear screw puffing equipment includes a screw puffing device, the screw speed is 40 - 80 revolutions per minute, the puffing temperature is 70°C to 110°C, and the puffing time is 10 - 15 minutes.

[0017] In a further embodiment, in step S4, the multi-stage drying operation includes a first-stage microwave drying, a second-stage microwave drying, and a third-stage microwave drying. The first-stage microwave drying has a microwave power of 1.0 kW and lasts for 5 - 8 minutes to remove free water; the second-stage microwave drying has a microwave power of 0.7 kW and lasts for 10 - 15 minutes to remove bound water; the third-stage microwave drying has a microwave power of 0.5 kW and combines infrared heating to maintain the particle moisture content at 8% - 10%.

[0018] In a further embodiment, in step S5, the functional coating includes nano-silver, chitosan, and bamboo vinegar liquid extract, and the spraying process uses electrostatic spraying technology to ensure a uniform and stable coating.

[0019] In a further embodiment, in step S2, the ultrasonic dynamic mixing device has an ultrasonic power of 20 - 40 kHz, an ultrasonic power of 500 - 2000 W, an ultrasonic action time of 5 - 20 min, and the ultrasonic mode is intermittent or continuous. The intermittent mode uses a cycle of ultrasonic for 5 s and pause for 3 s to reduce the influence of heat accumulation on the material structure. The ultrasonic action medium uses an aqueous phase or a co-dispersant to enhance the homogeneous mixing effect.

[0020] In a further embodiment, in step S6, the cat litter particles are packaged after being treated by an ultraviolet disinfection device to ensure the hygienic safety of the product. The ultraviolet irradiation intensity is 50 - 80 μW / cm 2 , and the disinfection time is 10 - 15 minutes.

[0021] In a further embodiment, the infrared heating uses infrared radiation to heat the particles, with a power of 0.7 kW and a drying time of 10 - 15 minutes.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention adopts technologies such as vacuum filtration, mixing, puffing granulation, and low-temperature drying, significantly improving the production efficiency, reducing energy consumption in multiple links, avoiding the processes of multiple drying and adding water, and improving the water absorption, deodorization, and antibacterial properties of the cat litter through a reasonable formula and the combination of new equipment. Moreover, the production process is more environmentally friendly. The present invention not only properly treats the wet bean dregs of soy product processing enterprises and converts them into efficient and environmentally friendly tofu cat litter to meet the market demand, but also avoids the problems of high energy consumption, loss, and pollution in the traditional production process of tofu cat litter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the process flow chart of the production of the present invention. Specific embodiments

[0024] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without one or more of these details. In other instances, well-known features have not been described in order to avoid obscuring the present invention.

[0025] Please refer to Figure 1 , the present invention provides a technical solution: a production process for preparing tofu cat litter from wet bean dregs by a one-step method, comprising the following steps:

[0026] S1. Treat the wet bean dregs with a multi-stage pressure filtration device with continuous vacuum assistance function. First, the moisture in the wet bean dregs is reduced from 95% to 70% through preliminary pressure filtration, and then secondary high-pressure vacuum pressure filtration is carried out to further reduce the moisture to 40%-50%;

[0027] Through the above steps, the burden of subsequent treatment is effectively reduced, the moisture content of the wet bean dregs is greatly reduced, the transportation and storage costs are reduced, and at the same time, over-drying and energy waste in the traditional process are avoided;

[0028] S2. Homogeneously mix the pressure-filtered wet bean dregs with a reinforcing agent, a binder, and a modifier in an ultrasonic dynamic mixing device to generate a semi-solid mixture with stable dispersibility;

[0029] Through the above steps, under the action of ultrasonic waves, water molecules in the wet bean dregs are excited by high-frequency vibration to form microbubbles, enhancing the dispersibility of the material, reducing the binding force between solid particles, and improving the homogeneous mixing efficiency. The transmission of ultrasonic energy enables the reinforcing agent and the binder to be evenly dispersed in the bean dregs matrix, promoting the adsorption and coating of the functional modifier, and finally forming a semi-solid mixture with excellent dispersibility and adhesiveness, with high mixing efficiency and a material utilization rate of over 95%;

[0030] S3. Feed the above mixed material into a high-shear screw puffing device with a temperature control feedback system for low-temperature puffing to ensure that microporous structures are formed inside the particles and the surfaces are smooth;

[0031] Through the above steps, the particle diameter is 2-5 mm, the porosity reaches 35%-45%, the water absorption reaches more than 300% of its own weight, and the removal rates of ammonia and formaldehyde exceed 95%, effectively improving the hygroscopicity, antibacterial property, and durability of the cat litter, reducing dust generation. The traditional hollow structure has few pores and a small surface area, resulting in poor water absorption and odor absorption effects;

[0032] S4. Use a microwave-infrared combined drying equipment to control the drying process in three stages, conduct multi-stage drying operations, and gradually remove the bound water in the expanded particles;

[0033] Through the above steps, the entire drying process can save more than 30% energy compared with traditional drying, and the drying effect is uniform;

[0034] S5. Spray a functional coating containing bamboo vinegar liquid, nano silver and chitosan on the surface of the particles to form a long-lasting antibacterial and deodorant protective film;

[0035] Through the above steps, the antibacterial and deodorant properties of the cat litter are effectively improved, and the deodorization efficiency reaches more than 96%, ensuring that the cat litter still maintains good performance after long-term use;

[0036] S6. Screen the modified particles according to the target particle size range to ensure the uniformity and physical properties of the particles. After packaging the finished products, conduct quantitative packaging through an automated packaging equipment;

[0037] Through the above steps, ensure that the particle size of the cat litter is between 2 - 5 mm, and package the cat litter into environmentally friendly bags of 2.5 kg, 5 kg, 10 kg or ton bags through an automated packaging system, ensuring that the quality of each bag of cat litter is consistent and meeting the needs of different consumers.

[0038] In a further embodiment, in step S2, the enhancer includes one or more of starch, nano calcium carbonate, nano silica aerogel, diatomite, modified wood fiber powder, bentonite, halloysite, vermiculite, zeolite, white carbon black, oyster shell powder. The weight ratio of starch is 10 - 30%, the weight ratio of nano calcium carbonate is 2% - 8%, the weight ratio of nano silica aerogel is 1 - 3%, the weight ratio of zeolite is 3% - 6%, the weight ratio of modified wood fiber powder is 3% - 18%, and the weight ratio of one or more of bentonite, halloysite, vermiculite, diatomite, white carbon black, oyster shell powder is 1% - 4%.

[0039] In a further embodiment, in step S2, the binder is a composite of acetylated cassava starch and modified natural plant gum. The weight ratio of acetylated cassava starch is 0.5% - 2%, the modified natural plant gum is a composite of sulfonated lignin / polyethylene glycol condensation gum, and the weight ratio is 0.5% - 1%. The mass ratio of sulfonated lignin to polyethylene glycol condensation gum is 0.3 - 0.7.

[0040] In a further embodiment, in step S2, the modifier includes a zeolite molecular sieve / nano silver complex, a nano cellulose reinforced starch glue, and a plant extract. The weight ratio of the zeolite molecular sieve / nano silver complex is 2%-4%, the weight ratio of the nano cellulose reinforced starch glue is 1%-5%, and the plant extract is a rosmarinic acid / cyclodextrin inclusion complex with a weight ratio of 2%-4%.

[0041] In a further embodiment, in step S3, the high-shear screw puffing equipment includes a screw-type puffing device. The screw speed is 40-80 revolutions per minute, the puffing temperature is 70°C to 110°C, and the puffing time is 10-15 minutes to ensure the stability of the microporous structure of the particles and good moisture retention capacity.

[0042] In a further embodiment, in step S4, the multi-stage drying operation includes the first-stage microwave drying, the second-stage microwave drying, and the third-stage microwave drying. The microwave power of the first-stage microwave drying is 1.0 kW and lasts for 5-8 minutes to remove free water; the microwave power of the second-stage microwave drying is 0.7 kW and lasts for 10-15 minutes to remove bound water; the microwave power of the third-stage microwave drying is 0.5 kW, combined with infrared heating, to maintain the moisture content of the particles at 8%-10%. Through the above multi-stage drying operation, compared with the traditional drying method, the energy consumption is reduced by more than 30%, and the drying is uniform, ensuring the stability of the product quality.

[0043] In a further embodiment, in step S5, the functional coating includes nano silver, chitosan, and bamboo vinegar extract. The electrostatic spraying technology is used in the spraying process to ensure the uniformity and stability of the coating. The coating thickness is 0.05-0.1 mm, and the deodorizing effect and antibacterial property of the coating last for more than 6 months.

[0044] In a further embodiment, in step S2, the ultrasonic power of the ultrasonic dynamic mixing device is 20-40 kHz, the ultrasonic power is 500-2000 W, the ultrasonic action time is 5-20 min, and the ultrasonic mode is intermittent or continuous. The intermittent mode adopts a cycle of ultrasonic for 5 s and stop for 3 s to reduce the influence of heat accumulation on the material structure. The ultrasonic action medium adopts an aqueous phase or a co-dispersant to enhance the homogeneous mixing effect.

[0045] In a further embodiment, in step S6, the cat litter particles are packaged after being treated by an ultraviolet disinfection device to ensure the hygienic safety of the product. The ultraviolet irradiation intensity is 50-80 μW / cm 2 , and the disinfection time is 10-15 minutes.

[0046] In a further embodiment, the infrared heating uses infrared radiation to heat the particles, with a power of 0.7 kW and a drying time of 10-15 minutes.

[0047] Example 1:

[0048] Raw material preparation: Wet soybean dregs from a tofu factory: 20 kg, water content 95%; Nano calcium carbonate: 1 kg; Starch: 1 kg (to enhance the hardness of the cat litter); Bamboo vinegar liquid: 0.5 kg (to enhance the deodorizing effect); Nano silver solution: 0.2 kg (antibacterial effect); Plant fiber powder: 0.5 kg (to improve water absorption); Sulfonated lignin: 1 kg (to improve particle strength); Chitosan: 0.3 kg (antibacterial and deodorizing effects).

[0049] Process flow: Pretreatment of wet soybean dregs: Use a belt vacuum filter press to reduce the water content of the wet soybean dregs from 95% to 42%; Raw material mixing: Uniformly mix the filtered wet soybean dregs with nano calcium carbonate, starch, bamboo vinegar liquid, nano silver solution, plant fiber powder, etc. in a high-efficiency screw mixer to obtain a mixture with excellent physical properties; Extrusion granulation: Feed the mixture into a low-temperature screw extruder, control the temperature at 80°C - 85°C, and the screw speed at 45 revolutions per minute to produce cat litter particles with a particle size of 2 - 5 mm; Drying treatment: Use a multi-stage microwave dryer for drying, reduce the microwave power from 1.0 kW to 0.6 kW, and control the drying time at 25 minutes to ensure that the water content of the cat litter is stably between 8% - 10%; Packaging: Feed the dried cat litter particles into an automatic packaging machine for metering and packaging.

[0050] Results: Water absorption: The water absorption rate of the cat litter is above 300%; Deodorizing effect: The combination of bamboo vinegar liquid and nano silver effectively removes ammonia, and the deodorization rate reaches above 95%; Shatter resistance: The particles have high anti-cracking performance and strong durability, meeting the needs of consumers.

[0051] Example 2:

[0052] Raw material preparation: Wet soybean dregs produced by a soybean protein extraction factory: 30 kg, water content 85%; White carbon black and modified lignocellulose: 1 kg; Starch: 2 kg (to enhance the hardness and particle stability of the cat litter); Bamboo vinegar liquid: 0.5 kg; Chitosan: 0.3 kg (antibacterial property); Acetylated tapioca starch: 1.2 kg (to improve particle strength); Nano silver solution: 0.3 kg.

[0053] Process flow: Wet soybean dregs pretreatment: Use a vacuum filter press to reduce the moisture content of wet soybean dregs from 85% to 45%; Nano-modification treatment: Add silica white, modified lignocellulose, starch, chitosan, nano-silver solution, etc. to wet soybean dregs and mix them evenly to ensure full combination of nano-materials and soybean dregs; Extrusion granulation: Feed the mixture into an extruder, control the temperature at 85°C, and the screw speed at 40 revolutions per minute to ensure uniform granule expansion. The granule size is controlled at 3 mm; Drying treatment: Use a microwave dryer, with the first-stage microwave power of 1.2 kW and a continuous drying time of 6 minutes; the second-stage microwave power of 0.9 kW and a continuous drying time of 8 minutes to ensure that the moisture content of the cat litter particles reaches about 10%; Packaging: Use an automated packaging system to complete packaging to avoid secondary pollution.

[0054] Results: Water absorption: The water absorption rate of the cat litter reaches over 300%; Antibacterial performance: Nano-silver materials significantly improve the antibacterial effect and inhibit bacterial growth; Deodorization effect: The synergistic effect of bamboo vinegar liquid and nano-silver enables the deodorization rate of the cat litter to reach 98%.

[0055] Example 3:

[0056] Raw material preparation: Pea wet soybean dregs produced from Longkou vermicelli: 25 kg, with a moisture content of 83%; Sulfonated lignin / polyethylene glycol condensation glue: 0.5 kg, starch: 1.5 kg (to enhance the strength and water absorption of the cat litter); Bamboo vinegar liquid: 0.5 kg; Gelatinous plant fiber: 1 kg (to enhance the water absorption and environmental protection of the cat litter); Zeolite: 1 kg (to increase the hardness of the cat litter particles).

[0057] Process flow: Wet soybean dregs pretreatment: Use a high-efficiency centrifuge to dehydrate the moisture content of wet soybean dregs from 83% to 50%; Raw material mixing: Use a screw mixer to evenly mix wet soybean dregs with sulfonated lignin / polyethylene glycol condensation glue, starch, bamboo vinegar liquid, plant fiber, etc.; Extrusion granulation: Feed the mixture into a low-temperature screw extruder, control the temperature at 75°C, and the screw speed at 50 revolutions per minute; Drying treatment: Use a natural gas low-temperature drying furnace, control the drying temperature at 50°C, and the drying time at 20 minutes. The final moisture content of the cat litter is 9%-10%; Packaging: Use an automated packaging machine for packaging.

[0058] Results: Water absorption: The water absorption rate of the cat litter reaches over 310% and can quickly absorb the urine of cats; Deodorization effect: Bamboo vinegar liquid effectively removes ammonia in cat urine, and the deodorization effect reaches 95%; Energy-saving effect: Using low-temperature drying and high-efficiency dehydration technology, the energy consumption is reduced by more than 30% compared with the traditional process.

[0059] Example 4:

[0060] Raw material preparation: Wet black bean dregs produced by soy milk / soy milk powder enterprises: 20 kg, with a water content of 81%; Halloysite: 1 kg, starch 2.5 kg (to improve strength); Bamboo vinegar liquid: 0.5 kg; Acetylated tapioca starch: 0.5 kg (to enhance adhesiveness); Nanofibers: 0.2 kg (to enhance the water absorbency and antibacterial property of the cat litter).

[0061] Process flow: Pretreatment of wet dregs: Use a rapid pressure filtration device to reduce the water content of the wet dregs from 81% to 48%; Raw material mixing: In a high-speed mixer, evenly mix the wet dregs with halloysite, starch, bamboo vinegar liquid, plant gum, etc.; Extrusion granulation: The mixed material is extruded through an extruder, with the temperature controlled at 80 °C, the screw speed at 55 revolutions per minute, and the particle size at 3 mm; Drying treatment: Use a tunnel dryer, with the temperature controlled at 90 °C and the drying time at 15 minutes, and finally the water content is controlled at 8% - 9%; Packaging: Package the dried cat litter particles through an automatic packaging machine.

[0062] Results: Water absorbency: The water absorption rate of the cat litter reaches over 300%; Deodorization effect: The combination of bamboo vinegar liquid and nanofibers effectively removes odors, with a deodorization rate of 97%; Production efficiency: The entire production process can be completed within 3 hours, saving 50% of the time compared to the traditional process.

[0063] Example 5:

[0064] Raw material preparation: Wet dregs produced by fermented bean curd / stinky tofu production enterprises: 35 kg, with a water content of 80%; Nanoscale silica aerogel: 2 kg, starch 0.8 kg (to enhance the hardness and water absorbency of the cat litter); Bamboo vinegar liquid: 0.7 kg (to enhance the deodorization effect); Nano silver ion solution: 0.4 kg (antibacterial effect); Wood fiber powder: 0.8 kg (to enhance water absorbency); Nanoscale calcium carbonate: 1 kg (to improve particle strength).

[0065] Process flow: Pretreatment of wet dregs: Process the wet dregs through a screw press to remove excess water, with the water content controlled at about 44%; Raw material mixing: Evenly mix the dehydrated wet dregs with nanoscale calcium carbonate, starch, bamboo vinegar liquid, nano silver ion solution, wood fiber powder, etc., to ensure full fusion of each raw material; Extrusion granulation: Process the mixed material through a low-temperature screw extruder, control the extrusion temperature at 70 °C, the screw speed at 45 revolutions per minute, and the particle size is controlled at 2 - 5 mm; Drying treatment: Use a high-efficiency microwave drying device, control the microwave power at 1.5 kW, and the drying time at 12 minutes to ensure that the water content of the cat litter reaches about 10%; Packaging: Use an automated packaging line to measure and package the cat litter to ensure the accuracy and hygiene of the packaging.

[0066] Results: Water absorbency: The water absorption rate of the cat litter reaches over 290%; Deodorization effect: The combination of bamboo vinegar liquid and nanofibers effectively removes odors, with a deodorization rate of 96%; Production efficiency: The entire production process can be completed within 2 hours, saving 40% of the time compared to traditional processes.

[0067] The present invention realizes the high-value utilization of wet soybean dregs through an innovative technology system. The present invention breaks through the traditional disposal paths of soybean dregs composting or feed, and directly converts wet soybean dregs into functional cat litter products through multi-stage co-production and a variety of innovative technologies. The production process is 42% more energy-efficient than traditional drying technologies, and the treatment of each ton of soybean dregs reduces CO 2 emissions by 1.5 tons, which highly conforms to the requirements of energy conservation and emission reduction. This technology system responds to the call of "promoting the resource utilization of agricultural waste" in the "Opinions on Accelerating the Construction of a Waste Recycling System", can not only solve the long-term problems of the soy products industry, but also fill the performance gap of environmentally friendly cat litter in the market, and provide an innovative resource recycling technology solution.

[0068] The present invention uses the above embodiments to illustrate the detailed composition and preparation method of the materials described in the present invention, but the present invention is not limited to the above detailed composition and preparation method, that is, it does not mean that the present invention must rely on the above detailed composition and preparation method to be implemented. Any improvement of the present invention, the equivalent substitution of each raw material and method of the products of the present invention, and the addition, deletion, and selection of specific methods of auxiliary components all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A production process for preparing tofu cat litter by one-step method using wet bean dregs, characterized in that: The steps include: S1. The wet okara is processed by a multi-stage filter press with continuous vacuum assistance, firstly reducing the moisture content of the wet okara from 95% to 70% by preliminary filtration, and then performing secondary high-pressure vacuum filtration to further reduce the moisture content to 40%-50%; S2. The wet dregs after the filter press are homogenously mixed with the reinforcing agent, the binder and the modifier in an ultrasonic dynamic mixing device to generate a semi-solid mixture with stable dispersion; S3. The mixed material is fed into a high shear screw extruder with a temperature control feedback system for low-temperature extrusion to ensure that a microporous structure is formed inside the particles and the surface is smooth; S4. Use microwave-infrared combined drying equipment to control the drying process in three stages, perform multi-stage drying operations, and gradually remove the bound water in the expanded particles; S5. Spraying a functional coating containing bamboo vinegar, nanosilver and chitosan on the surface of the particles to form a durable antibacterial and deodorizing protective film; S6. The modified particles are screened according to the target particle size range to ensure the uniformity and physical properties of the particles. After the finished products are packaged, they are quantitatively packaged through automated packaging equipment.

2. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S2, the reinforcing agent includes one or more of starch, nano-calcium carbonate, nano-silicon dioxide aerogel, diatomaceous earth, modified wood fiber powder, bentonite, halloysite, vermiculite, zeolite, white carbon black, and oyster shell powder, wherein the weight of the starch accounts for 10-30%, the weight of the nano-calcium carbonate accounts for 2%-8%, the weight of the nano-silicon dioxide aerogel accounts for 1-3%, the weight of the zeolite accounts for 3%-6%, the weight of the modified wood fiber powder accounts for 3%-18%, and the weight of the bentonite and one or more of halloysite, vermiculite, diatomaceous earth, white carbon black, and oyster shell powder accounts for 1%-4%.

3. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S2, the binder is a composite of acetylated cassava starch and modified natural plant gum, the weight proportion of the acetylated cassava starch is 0.5%-2%, the modified natural plant gum is a composite of sulfonated lignin / polyethylene glycol condensation glue, the weight proportion is 0.5%-1%, and the mass ratio of the sulfonated lignin to the polyethylene glycol condensation glue is 0.3-0.

7.

4. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S2, the modifier includes a zeolite molecular sieve / nanosilver complex, nanocellulose enhanced starch glue and a plant extract, wherein the weight proportion of the zeolite molecular sieve / nanosilver complex is 2%-4%, the weight proportion of the nanocellulose enhanced starch glue is 1%-5%, and the plant extract is a rosmarinic acid / cyclodextrin inclusion complex, which accounts for 2%-4% by weight.

5. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S3, the high shear screw puffing equipment includes a screw puffing device, the screw speed is 40-80 rpm, the puffing temperature is 70° C. to 110° C., and the puffing time is 10-15 minutes.

6. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S4, the multi-stage drying operation includes a first stage microwave drying, a second stage microwave drying and a third stage microwave drying, wherein the microwave power of the first stage microwave drying is 1.0 kW and lasts for 5-8 minutes to remove free water; The microwave power of the second stage microwave drying is 0.7 kW, which lasts for 10-15 minutes and is used to remove bound water; the microwave power of the third stage microwave drying is 0.5 kW, combined with infrared heating, to maintain the moisture content of the particles at 8%-10%.

7. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S5, the functional coating includes nanosilver, chitosan and bamboo vinegar extract, and the spraying process adopts electrostatic spraying technology to ensure that the coating is uniform and stable.

8. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S2, the ultrasonic dynamic mixing device has an ultrasonic power of 20-40kHz, an ultrasonic power of 500-2000W, an ultrasonic action time of 5-20min, and an ultrasonic mode of intermittent or continuous. The intermittent mode adopts a cycle of ultrasonic 5s and stop 3s to reduce the influence of heat accumulation on the material structure. The ultrasonic action medium adopts water phase or dispersant to enhance the homogeneous mixing effect.

9. The production process for preparing tofu cat litter by a one-step method using wet bean dregs according to claim 1, characterized in that: In step S6, the cat litter particles are packaged after being treated by an ultraviolet disinfection device to ensure the hygienic safety of the product. The ultraviolet irradiation intensity is 50-80 μW / cm 2 , the disinfection time is 10-15 minutes.

10. The production process for preparing tofu cat litter by one-step method using wet bean dregs according to claim 6, characterized in that: The infrared heating uses infrared radiation to heat the particles, with a power of 0.7 kW and a drying time of 10-15 minutes.

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