Improved kitchen waste pretreatment process

Abstract

The invention provides an improved kitchen waste pretreatment process which comprises the following steps: S1, hydraulic pulping: conveying kitchen waste into a hydraulic pulping machine, separating out heavy substances with the density greater than that of water and light substances with the density smaller than that of water, and mixing the light substances with water to form light substance slurry; s2, light substance sorting: the light substance slurry is conveyed into a light substance sorting machine, undersize products and oversize products are obtained through sorting, and the undersize products are conveyed into a slurry pool; s3, crushing and pulping: conveying the oversize product into a crushing cavity of a crushing, impurity-removing and pulping all-in-one machine, and meanwhile, injecting clear water to prepare mixed pulp; s4, impurity removal and separation are conducted, specifically, the mixed slurry is separated through a screen, kitchen waste slurry and other impurities are obtained, the kitchen waste slurry is conveyed into a slurry pool, and the other impurities are conveyed outwards to be incinerated; s5, organic matter extraction: leading the slurry pool to a three-phase centrifugal machine, and storing the organic matter in an organic material bin; the method has the effects of improving the resource utilization rate of the kitchen waste and improving economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of garbage treatment, and particularly relates to an improved pretreatment process for kitchen waste. Background Art

[0002] Kitchen waste is a type of garbage containing a relatively large amount of organic matter and has high recyclable value. In some areas where garbage classification has not been carried out, all garbage is treated in a centralized manner, and a large amount of sundries are mixed in the kitchen waste, including some domestic garbage such as wooden sticks, spatulas, iron basins, cotton quilts, and so on. In the related art, the hydraulic crushing and pulping technology is the mainstream pretreatment process for kitchen waste. This technology breaks the kitchen waste into pulp by the impact of water flow and separates heavy substances (such as ironware, sand, bones, etc.) and light substances by using density differences. The light substances are further processed by a separator, the undersize enters the oil extraction system, and the oversize is recycled after treatment.

[0003] In view of the above related art, although the hydraulic pulping process can separate heavy substances, there is a lack of effective treatment means for the oversize after sorting of light substances. A large amount of unbroken organic materials (such as fruit and vegetable residues, meat fibers, etc.) are mixed in the oversize. Due to the mixing of inorganic light substances, it cannot be directly used for resource utilization, resulting in waste of organic resources. At the same time, additional incineration or landfill costs need to be paid, resulting in low resource utilization rate and low economic benefits of kitchen waste. Summary of the Invention

[0004] The purpose of the present invention is to provide an improved pretreatment process for kitchen waste to solve the problems of low resource utilization rate and low economic benefits of kitchen waste.

[0005] In order to achieve the above purpose, an improved pretreatment process for kitchen waste of the present invention adopts the following technical solutions:

[0006] An improved pretreatment process for kitchen waste, characterized by comprising the following steps:

[0007] S1. Hydraulic pulping: Place the kitchen waste in a hydraulic pulping machine, and break and pulp the kitchen waste by hydraulic impact to separate heavy substances with a density greater than that of water and light substance pulp with a density less than that of water;

[0008] S2. Light substance sorting: Put the light substance pulp into a light substance separator, and obtain undersize and oversize through sorting;

[0009] S3. Crushing and pulping: Put the oversize into a crushing, impurity-removing and pulping integrated machine for crushing, and inject clear water to obtain mixed pulp;

[0010] S4. Impurity removal and separation: Separate the mixed slurry through a sieve to obtain food waste slurry and coarse granular impurities. The food waste slurry is transported to the organic silo for storage, and other impurities and the heavy substances in step S1 are transported and aggregated by a screw conveyor for external incineration treatment.

[0011] S5. Organic matter extraction: The slurry pool leads to a three-phase centrifuge. After passing through the three-phase centrifuge, oil, wastewater, and organic matter are output, and the organic matter is stored in the organic silo.

[0012] As an optimization of an improved food waste pretreatment process, before step S1, it also includes preliminarily sorting the food waste collected from the garbage station to remove large impurities with a single volume greater than 1000 cubic centimeters.

[0013] As an optimization of an improved food waste pretreatment process, in step S2, the screen aperture of the light matter separator is 3 - 5 mm.

[0014] As an optimization of an improved food waste pretreatment process, in step S2, the treatment steps in the slurry pool include oil extraction treatment and organic matter sedimentation.

[0015] As an optimization of an improved food waste pretreatment process, in step S3, the crushing particle size of the crusher is controlled to be 5 - 8 mm.

[0016] As an optimization of an improved food waste pretreatment process, in step S3, the moisture content of the mixed slurry is controlled to be 80 - 95%.

[0017] As an optimization of an improved food waste pretreatment process, in step S3, the crushing, impurity removal, and pulping integrated machine is directly connected to the oversize outlet of the light matter separator.

[0018] As an optimization of an improved food waste pretreatment process, in step S5, it also includes transferring the organic matter in the organic silo to a black soldier fly breeding device or an anaerobic fermentation reactor.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (1) Significantly improve the utilization rate of organic materials: By adding a crushing, impurity removal, and pulping step at the rear end of the light matter separator, the oversize mixed with inorganic light matter is further crushed, impurities are removed, and food waste slurry is made, effectively extracting the organic materials in the oversize, avoiding resource waste caused by direct abandonment, realizing resource utilization, and enhancing economic benefits.

[0021] (2) Reduce the subsequent treatment cost: Through crushing and pulping and screen separation, the viscosity of the oversize of the organic materials is reduced and the looseness is increased, making it more adaptable to the conveying characteristics of the screw conveyor, reducing the equipment blockage rate, and reducing the maintenance cost.

[0022] (3) Strong process compatibility: The newly added steps are seamlessly connected to the existing hydraulic pulping process. There is no need to modify the original equipment. Only a crushing and impurity-removing pulping machine needs to be added at the rear end of the separator, with low transformation cost and easy to promote. Specific implementation manners

[0023] To make the technical solutions and advantages of the present invention clearer, the present invention and its beneficial effects will be further described in detail below in conjunction with specific implementation manners, but the implementation manners of the present invention are not limited thereto.

[0024] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0025] The standard parts used in the present invention can all be purchased from the market. The special-shaped parts can be customized according to the description in the specification. The specific connection methods of each part all adopt conventional means such as bolts, rivets, welding, etc. that are mature in the prior art. The machines, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be elaborated here.

[0026] The following further elaborates on the present application in conjunction with specific implementation steps.

[0027] The present application provides an improved pretreatment process for kitchen waste, including the following steps:

[0028] Step S1, hydraulic pulping:

[0029] The kitchen waste collected from the garbage station is preliminarily sorted, and after removing the large foreign objects with a single volume greater than 1000 cubic centimeters, the sorted kitchen waste is then transported to a hydraulic pulping machine. Diluted water is continuously injected into the hydraulic pulping machine. Under the agitation of the crushing cutter head of the hydraulic pulping machine, the kitchen waste is initially crushed by hydraulic impact and the crushing cutter head. The food residues, fruits and vegetables, etc. mixed in the waste form a light material slurry in a solid-liquid mixed state under the water flow impact, while the impurities with relatively high density such as ironware and sand stay in place to form heavy substances, and are transported to the corresponding outlets through a screw conveyor. Through this step, heavy substances can be effectively separated, providing a basis for subsequent light material sorting and reducing the risk of equipment jamming.

[0030] Step S2, light material sorting:

[0031] Put the light - matter slurry into a light - matter separator. The aperture of the sieve mesh of the light - matter separator is 3 - 5 mm. In this embodiment, the aperture of the sieve mesh is selected as 4 mm. Through the light - matter separator, the light - matter slurry can be preliminarily separated into solid and liquid, divided into undersize materials and oversize materials. Among them, the undersize materials are oil, water, and debris with a particle size less than or equal to 4 mm. The undersize materials are transported to the slurry pool; the oversize materials are a mixture of organic materials and inorganic materials with a particle size greater than 4 mm. Through this step, part of the organic matter can be separated, improving the resource recovery utilization rate.

[0032] Step S3, crushing and pulping:

[0033] Transport the oversize materials to the crushing chamber of the crushing, impurity - removing and pulping integrated machine through a screw conveyor for secondary crushing. The crushing particle size is controlled within 5 - 8 mm. In this embodiment, the crushing particle size is 1 mm to ensure that the organic materials are fully refined. At the same time, recycled water is injected into the crushing, impurity - removing and pulping integrated machine. Under the action of the crushing and stirring of the crushing blades, a mixed slurry with a water content of 80 - 95% is obtained. In this embodiment, the water content of the mixed slurry is 85%. Through this step, the food residues and fruit and vegetable fibers in the food waste can be physically crushed, converted into finer organic matters, thereby improving the fluidity of the slurry and reducing the equipment blockage rate.

[0034] Furthermore, the crushing, impurity - removing and pulping integrated machine is directly connected to the oversize material outlet of the light - matter separator. Through this step, the crushing, impurity - removing and pulping integrated machine can be directly arranged on the basis of the original process route without modifying the original production line, which is beneficial to saving the production line transformation cost.

[0035] Step S4, impurity removal and separation:

[0036] Separate the mixed slurry through a 6 - mm sieve mesh to obtain food waste slurry and other sundries. The food waste slurry is transported to the slurry pool in Step S2, and the remaining sundries are transported to the outlet through a screw conveyor and summarized with the heavy materials in Step S1 to the collection box for external incineration treatment to generate calorific value. Through this step, the organic materials with higher recovery value can be distinguished from other coarse - grained sundries and treated through different channels, thereby improving the economic benefits of the resource utilization of food waste. In actual production, the organic matter resource utilization rate in food waste can be increased by 30% through the materials separated in this step, saving more than 200,000 yuan in annual landfill costs.

[0037] Step S5, organic matter extraction:

[0038] The mixed slurry pool after steps S2 and S4 is fed into a three-phase centrifuge for oil extraction. After passing through the three-phase centrifuge, the slurry outputs oil, wastewater, and solid-phase organic matter. The vegetable oil and animal oil are refined to recover resources. The wastewater is discharged into the sewage treatment pool, and the solid-phase organic matter is transported to the organic silo for storage. Through this step, recyclable resources can be treated separately, improving the resource recovery rate.

[0039] Furthermore, the organic matter in the organic silo is transferred to a black soldier fly breeding device and used as feed for insect cultivation to improve economic benefits; or the organic matter in the organic silo is transferred to an anaerobic fermentation reactor to generate biogas, which is incorporated into the natural gas network to improve economic benefits.

[0040] Based on the disclosure and teachings of the above specification, those skilled in the art of the present invention can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the above specific embodiments, and any obvious improvements, substitutions, or variations made by those skilled in the art on the basis of the present invention fall within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. An improved pretreatment process for kitchen waste, characterized in that, It includes the following steps: S1. Hydrodynamic pulping: Put the kitchen waste into a hydrodynamic pulping machine, and crush and pulp the kitchen waste through hydrodynamic impact and a crushing cutter head to separate heavy substances with a density greater than that of water and light substances with a density less than that of water. The light substances are mixed with water to form a light-substance slurry; S2. Light-substance separation: Transport the light-substance slurry to a light-substance separator, and obtain undersize materials and oversize materials through separation. The undersize materials are transported to a slurry pool; S3. Crushing and pulping: Transport the oversize materials to the crushing chamber of an integrated crushing, impurity-removing and pulping machine, and inject clear water at the same time to obtain a mixed slurry; S4. Impurity removal and separation: Separate the mixed slurry through a screen to obtain kitchen waste slurry and other sundries. The kitchen waste slurry is transported to the slurry pool in step S2, and the other sundries and the heavy substances in step S1 are transported and aggregated through a screw conveyor and are transported out for incineration treatment; S5. Organic matter extraction: The slurry pool leads to a three-phase centrifuge. After the slurry passes through the three-phase centrifuge, oil, wastewater and organic matter are output, and the organic matter is stored in an organic material bin.

2. An improved pretreatment process for kitchen waste according to claim 1, characterized in that, Before step S1, it also includes preliminarily sorting the kitchen waste collected from the garbage station to remove large sundries with a single volume greater than 1000 cubic centimeters.

3. An improved pretreatment process for kitchen waste according to claim 1, characterized in that, In step S2, the screen aperture of the light-substance separator is 3-5 mm.

4. An improved pretreatment process for kitchen waste according to claim 1, characterized in that, In step S2, the treatment steps in the slurry pool include oil extraction treatment and organic matter sedimentation.

5. An improved pretreatment process for kitchen waste according to claim 1, characterized in that, In step S3, the crushing particle size of the crusher is controlled to be 5-8 mm.

6. An improved pretreatment process for kitchen waste according to claim 1, characterized in that, In step S3, the moisture content of the mixed slurry is controlled to be 80-95%.

7. An improved pretreatment process for kitchen waste according to claim 1, wherein in step S3, the integrated crushing, impurity-removing and pulping machine is directly connected to the oversize material outlet of the light-substance separator.

8. An improved pretreatment process for kitchen waste according to claim 1, wherein in step S5, it also includes transferring the organic matter in the organic material bin to a black soldier fly breeding device or an anaerobic fermentation reactor.