CN110538858A - Method and system for separating impurities from kitchen waste - Google Patents

Abstract

The invention discloses a method and system for separating impurities from kitchen waste. The method includes pulping by hydraulic cracking, separation of light and heavy impurities, and output of garbage. Food waste is crushed; light and heavy debris are separated into pulp by hydraulic cracking, and then stratified to form light garbage, intermediate slurry, and heavy garbage; garbage output: light garbage, intermediate slurry, heavy garbage The garbage is output separately, and the light garbage is squeezed and dehydrated after output; the intermediate slurry is treated as a resource, and the heavy garbage is landfilled after output. The method adopts hydraulic cracking pulping, which not only breaks the kitchen waste, but also separates light and heavy waste. The method and system have no mechanical crushing and sorting links, and the slurry has less impurities, high purity, and high resource utilization efficiency. It solves the problem that the existing kitchen waste pretreatment process is cumbersome.

Description

A method and system for separating food waste impurities

technical field

The invention belongs to the field of kitchen waste treatment, and in particular relates to a method and system for separating food waste impurities.

Background technique

In August 2011, the National Development and Reform Commission, the Ministry of Finance, the Ministry of Housing and Urban-Rural Development and other relevant departments launched the pilot work of resource utilization and harmless treatment of catering waste in cities, and successively publicized 5 batches, accumulatively 100 pilot cities for catering waste treatment ( districts), covering 32 provincial-level administrative regions. After these years of exploration, the domestic catering waste treatment technology has gradually transitioned from the "overall introduction" to the "digestion, absorption and innovation" stage, and gradually returned to the research and development of catering waste treatment technology and equipment manufacturing in line with my country's national conditions.

After nearly ten years of development, the domestic process technology in the field of catering waste treatment has developed from the early landfill, incineration, and direct drying as feed to the current stage of microbial treatment technology/aerobic composting suitable for small-scale, and large-scale Advanced anaerobic digestion technology.

At present, the vast majority (about 90%) of domestic catering waste treatment projects adopt anaerobic biogas production process. After years of development, anaerobic process is basically mature, and many related projects have been built. There is also a certain guarantee, but there are still common problems in the processing process such as poor quality of raw materials, low efficiency of debris removal, and unstable operation results.

Chinese invention patent "food waste pretreatment system" (CN110014018A), published on July 16, 2019, discloses a food waste pretreatment system, including a filter device, a coarse crushing device, a fine crushing device, and a three-phase separation devices, of which the coarse crushing and fine crushing devices are hammer crushers. Since the hammer blades of this type of crusher are consumable materials, the hammer blades need to be replaced irregularly, so the maintenance is relatively cumbersome.

Chinese invention patent "a food waste screening and pulping system and pulping process" (CN106311721B), the authorized announcement date is June 12, 2018, which discloses a food waste screening and pulping system, including a crusher , pulping machine and other equipment. Before pulping, this process is equipped with crushing and screening links, which has a long process chain and complicated procedures.

The Chinese invention patent "New Food Waste Pretreatment System and Treatment Method", published on November 27, 2018, announced a new type of food waste pretreatment system and treatment method. The method includes a solid-liquid separation device, a roller sorter, a metal detector, a shredder, a small roller sorter, etc., wherein the solid-liquid separation device is a shaftless screw conveyor similar to an inclination, through bottom-to-bottom The upper part conveys solid matter, while the liquid flows out through the lower part of the screen by gravity. The process equipment is many, the process is long, and the operation procedure is also relatively cumbersome.

At present, in the field of food waste treatment, the existing impurity removal and pulping process is relatively complicated, so it is particularly necessary to develop a new food waste pretreatment process.

Contents of the invention

The invention provides a method and system for separating impurities from kitchen waste. The method adopts hydraulic cracking pulping, and utilizes hydraulic pulping to break and separate, which not only breaks up kitchen waste, but also separates light and heavy waste. The method and system have no mechanical crushing and sorting links, and the slurry has less impurities, high purity, and high resource utilization efficiency. The problem of cumbersome pretreatment process of the existing kitchen waste is solved.

In order to solve the above problems, the technical solution of the present invention is:

A method for separating impurities from food waste, including pulping by hydraulic cracking, separation of light and heavy impurities, and garbage output;

Wherein, the hydraulic cracking pulping is to use the impact and shear force generated by the hydraulic turbulence to crush the kitchen waste, and the large particles of organic matter are broken into small particle materials;

Separation of light and heavy debris into kitchen waste. After the hydraulic cracking and pulping, the standing time can be 10 to 15 minutes. The difference in material density is used to realize automatic stratification to form light waste, intermediate slurry, heavy waste;

Garbage output: output the light garbage, the intermediate slurry, and the heavy garbage respectively,

The light waste is mainly fabrics, plastics and fibers in the kitchen waste, and the light waste is squeezed and dehydrated after output;

The intermediate slurry is mainly kitchen food slurry, corrosive vegetables and fruits and fruit peels, etc., which are processed as resources;

The heavy waste is mainly inorganic heavy substances such as sand, stone, metal, glass, bone, shell, etc., which are landfilled.

Preferably, a vertical hydraulic pulper is used for hydrocracking pulping.

Preferably, the resource treatment of the intermediate slurry can be performed by anaerobic digestion to prepare biogas or by oil extraction.

The present invention also provides a system for separating impurities from kitchen waste, including: hydraulic cracking pulping equipment, light waste conveyors, slurry pumps, heavy waste conveyors, and extruders;

The hydraulic cracking pulping equipment includes a light garbage outlet, an intermediate slurry outlet and a heavy garbage outlet, wherein the light garbage outlet of the hydraulic cracking pulping equipment is connected to the light garbage conveyor, and the hydraulic cracking The intermediate slurry outlet of the pulping equipment is connected to the slurry delivery pump, the heavy garbage outlet of the hydraulic cracking pulping equipment is connected to the heavy garbage conveyor; the light garbage conveyor is connected to the extruder.

Preferably, the hydraulic cracking pulping equipment is a vertical hydraulic pulping machine, the diameter of the bottom rotor is, for example, 700mm, and when rotating at a high speed, hydraulic turbulence is generated.

Preferably, the outlet of the slurry delivery pump is connected to an anaerobic tank or a decanter centrifuge to process the intermediate slurry as a resource.

Preferably, the extruder is a horizontal waste paper baler, and the moisture content after the horizontal waste paper baler is not greater than 45%, which reduces the volume and moisture content of light garbage and improves transportation efficiency.

Preferably, the light waste conveyor is a first U-shaped groove shaftless screw conveyor.

Preferably, the heavy waste conveyor is a second U-shaped groove shaftless screw conveyor.

Compared with the prior art, the present invention has the following advantages and positive effects due to the adoption of the above technical scheme:

The invention uses the hydraulic cracking pulping equipment to separate and pulp the kitchen waste. This process does not require a sorting system before, and is suitable for direct treatment of unsorted food waste. Hydraulic cracking pulping completes the cracking of organic matter in kitchen waste and the separation of light and heavy garbage at the same time, and separates light garbage such as non-degradable plastics from heavy garbage such as sand, shells, and bones. The light garbage is thrown away under the action of centrifugal force, and is distributed in a ring on the edge of the hydraulic pulper tank, and the heavy garbage is deposited in the center of the tank bottom. The heavy waste is buried, and the light waste is squeezed after output, which can be used as a resource, and the slurry in the middle can be used for subsequent resource treatment.

A preferred embodiment of the present invention adopts a vertical hydraulic pulping machine. When the bottom turntable is rotating, the material moves from top to bottom along the surface of the turntable. After moving to the top of the turntable, it is thrown to the edge of the tank by the turntable under the action of centrifugal force, and Rising along the tank, then falling back to the bottom of the turntable, forming a strong hydraulic impact and shearing action, the materials will rub and knead each other, and finally dissociate into fine particles. Finally, a homogenized slurry is obtained. The slurry particles are small and uniform, which is beneficial to the subsequent sufficient anaerobic digestion; and the light garbage is thrown away under the action of centrifugal force and distributed in a ring on the edge of the hydropulper tank. , the heavy garbage is deposited in the center of the bottom of the tank, and the intermediate slurry is in the center. Therefore, a hydraulic pulper can be used, which can not only crush garbage and make pulp, but also separate light and heavy garbage and slurry for subsequent processing.

Description of drawings

Fig. 1 is a simple flow chart of the method for separating impurities from kitchen waste provided by an embodiment of the present invention;

Fig. 2 is a flow chart of a specific method for separating impurities from food waste provided by an embodiment of the present invention.

Explanation of reference numerals: 1-hydraulic cracking pulping equipment; 2-horizontal shredder baler.

Detailed ways

A method and system for separating food waste impurities proposed by the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Advantages and features of the present invention will be apparent from the following description and claims.

Referring to Figure 1 and Figure 2, in one embodiment, with a processing capacity of 100t/d, the specific food waste pretreatment method and the system used are as follows:

Firstly, the food waste is transported to the hydraulic cracking pulping equipment 1, which can be fed by conventional shaftless screw conveying equipment. There are many sundries in the food waste, and the material density varies greatly, especially the food waste is particularly viscous. The purpose of hydraulic cracking pulping is to use hydraulic turbulence to separate the waste from each other and avoid sticking together. Hydraulic cracking pulping equipment 1 adopts a vertical hydraulic pulping machine (power 110kw, effective volume 10m ³ , diameter 3000mm) common in papermaking technology for hydraulic cracking pulping, and the cracking time is 10-15 minutes. Because the vertical hydraulic pulper can not only crush food waste, but also separate light and heavy debris;

After the hydraulic cracking pulping process, the garbage is left to stand for 10 to 20 minutes, and the material deposition is completed. The heavy garbage is in the center, and the light garbage is distributed on the edge of the tank body in a ring shape. At this time, first open the valve at the center of the bottom, discharge the heavy garbage under the action of gravity, use the heavy garbage conveyor (the second U-shaped groove shaftless screw conveyor) to output, and then carry out landfill treatment;

After the heavy waste is discharged, open the light waste discharge valve, and use the light material conveyor (the second U-shaped groove shaftless screw conveyor, conveying capacity: 30m ³ /h, five-axis screw, U-shaped groove diameter 500mm) to output , and then use the horizontal shredder baler 2 (YCY14-B, rated pressure 30Mpa, processing capacity 8-10 packs/hour) to squeeze and pack, which can be recycled or incinerated; finally, the slurry discharge valve is opened, and the centrifugal The pump (150m ³ /h, head: 27-30m) outputs the slurry. One option is to transport the slurry to an anaerobic tank for biogas preparation, and the other option is to transport it to a decanter centrifuge for oil-water separation for oil extraction.

The whereabouts of light and heavy garbage and slurry products generated after the application of the above methods are shown in the table below:

Specification Production capacity (t/d) whereabouts light waste 6 Recycling heavy waste 2 landfill disposal Intermediate slurry 92 Recycling total 100

The method and system for separating impurities from food waste provided in this example first uses hydraulic cracking and pulping of food waste, and the purpose is to use the characteristics of high water content of food waste to perform hydraulic impact and shear force on the waste. Crack, and then use centrifugal force to separate light and heavy impurities. Compress and package light waste for incineration or recycling, landfill heavy waste, and prepare biogas or extract oil from the intermediate slurry. Therefore, the process method of this embodiment has a high degree of automation, and the process is particularly simple. It not only efficiently removes light impurities such as plastics and fibers mixed in the food waste, but also removes sand, glass, metal, etc. mixed in the food waste. Heavy impurities, the separation effect of impurities is remarkable.

This embodiment adopts the common vertical hydraulic pulper in the papermaking process. When the bottom turntable is rotating, the material moves from top to bottom along the surface of the turntable. After moving to the top of the turntable, it is thrown to the edge of the tank by the turntable under the action of centrifugal force. , and rise along the tank, and then fall back to the bottom of the turntable, forming a strong hydraulic impact and shearing action, the materials produce mutual friction, kneading, and finally dissociate into fine particles. Finally, a homogenized slurry is obtained, with small particles and good uniformity, which is conducive to subsequent sufficient anaerobic digestion.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and equivalent technologies, they still fall within the protection scope of the present invention.

Claims (10)

1. A method for separating impurities from kitchen waste is characterized by comprising the steps of hydraulic breaking pulping, light and heavy impurity separation and waste output;

The hydraulic breaking pulping is to crush the kitchen waste by using impact and shearing force generated by hydraulic turbulence;

separating light and heavy impurities into light garbage, intermediate slurry and heavy garbage after hydraulic breaking pulping, and standing for layering;

And (3) garbage output: respectively outputting the light garbage, the intermediate slurry and the heavy garbage, and extruding and dehydrating the light garbage after outputting;

And carrying out resource treatment on the intermediate slurry, and carrying out landfill treatment after the heavy garbage is output.

2. the method for separating impurities from kitchen waste according to claim 1, characterized in that a vertical hydraulic pulper is used for hydraulic breaking pulping.

3. the method for separating impurities from kitchen waste according to claim 1, characterized in that the intermediate slurry is subjected to anaerobic digestion to produce biogas.

4. The method for separating impurities from kitchen waste according to claim 1, characterized in that the intermediate slurry is subjected to oil extraction treatment.

5. The utility model provides a kitchen garbage impurity separation's system which characterized in that includes: hydraulic breaking pulping equipment, a light garbage conveyor, a slurry conveying pump, a heavy garbage conveyor and an extruder;

The hydraulic breaking pulping equipment comprises a light garbage outlet, an intermediate slurry outlet and a heavy garbage outlet, wherein the light garbage outlet of the hydraulic breaking pulping equipment is connected with the light garbage conveyor, the intermediate slurry outlet of the hydraulic breaking pulping equipment is connected with the slurry conveying pump, and the heavy garbage outlet of the hydraulic breaking pulping equipment is connected with the heavy garbage conveyor; the light garbage conveyor is connected with the extruding machine.

6. The system for separating impurities in kitchen waste according to claim 5, wherein said hydraulic breaking pulping apparatus is a vertical hydraulic pulping machine.

7. the system for separating impurities in kitchen waste according to claim 5, characterized in that the outlet of said slurry delivery pump is connected to an anaerobic tank or a horizontal screw centrifuge.

8. the kitchen waste impurity separation system according to claim 5, wherein the extruder is a horizontal waste paper baler.

9. The system for separating impurities from kitchen waste according to claim 5, wherein said light waste conveyor is a first U-shaped groove shaftless screw conveyor.

10. The system for separating impurities in kitchen waste according to claim 5 or 9, characterized in that said heavy waste conveyor is a second U-shaped trough shaftless screw conveyor.