A process for garbage sorting and its system and application

Abstract

The present invention relates to a process for garbage sorting, a system and an application thereof, and relates to the technical field of garbage disposal. The process includes: low-temperature wet-heat hydrolysis, dehydration: crushing garbage, low-temperature wet-heat hydrolysis, dehydration, and obtaining dehydrated materials; the temperature of low-temperature wet-heat hydrolysis is 55°C-65°C, and the time is 9h-12h; biological drying: using drying gas, thermophilic bacteria and reflux organic matter, the dehydrated material is biologically dried to obtain dried materials; the temperature of biological drying is 65°C-75°C, and the time is 1.5 days-2.5 days; mechanical sorting: mechanical sorting of dried materials. The process combines low-temperature wet-heat hydrolysis and biological drying, allowing the cells in biomass garbage to break the wall, the cell fluid to flow out, and then by inoculating thermophilic bacteria, the organic matter is effectively degraded, and the heat generated by the degradation reaction is used to further reduce the water content in the garbage, and finally solve the problem that the biomass garbage is adhered after corruption and cannot be effectively mechanically sorted.

Description

Technical Field

[0001] The present invention relates to the technical field of garbage disposal, and in particular to a process for garbage sorting and a system and application thereof. Background Art

[0002] Due to factors such as economic and social development, most cities in my country still do not sort garbage thoroughly, and there is still a large amount of mixed garbage transportation mode. Mixed garbage often has the characteristics of high moisture content, low calorific value and complex composition. If it is directly treated by incineration or landfill, there are disadvantages such as low treatment efficiency, low income, heavy pollution and inability to maintain stable operation.

[0003] The current mixed waste sorting technology mainly uses a single method of mechanical sorting. However, due to the fact that some organic waste has begun to decay and produce filtrate during the waste transportation process, the mechanical sorting equipment cannot handle materials rich in moisture and viscosity, making the sorting work unable to operate stably. Therefore, a process and system for waste sorting that can reduce the amount of mixed waste, recycle it, and make it harmless is needed. Summary of the invention

[0004] In view of the above problems, the present invention provides a process for garbage sorting, which combines low-temperature hot and wet hydrolysis and biological drying processes, so that the cells in the biomass garbage are broken and the cell fluid flows out, and hydrolysis wastewater is obtained and discharged, thereby reducing the difficulty of subsequent dehydration. In the biological drying step, the hydrolyzed material is directly inoculated with thermophilic bacteria and thermophilic bacteria carried in the refluxed organic matter, thereby effectively degrading the organic matter. At the same time, the heat generated during the degradation reaction is used to further reduce the water content in the garbage, ultimately solving the problem that the mixed garbage contains biomass garbage, resulting in adhesion after corruption and unable to achieve effective mechanical sorting, thereby causing difficulties in garbage resource utilization.

[0005] In order to achieve the above object, the present invention provides a process for garbage sorting, which comprises the following steps:

[0006] Low-temperature wet-heat hydrolysis and dehydration: crush the garbage to obtain the material to be treated, perform low-temperature wet-heat hydrolysis on the material to be treated to obtain hydrolyzed material and hydrolyzed wastewater, dehydrate the hydrolyzed material to obtain dehydrated material and dehydrated wastewater; the temperature of the low-temperature wet-heat hydrolysis is 55°C-65°C, and the time of the low-temperature wet-heat hydrolysis is 9h-12h;

[0007] Biological drying: using drying gas, thermophilic bacteria and reflux organic matter to biologically dry the dehydrated material to obtain dried waste gas and dried material; the reaction temperature of the biological drying is 65°C-75°C, and the reaction time of the biological drying is 1.5 days-2.5 days;

[0008] Mechanical sorting: Mechanically sort the dried materials to obtain recycled materials and reflux organic matter.

[0009] By adopting the above process, the two processes of low-temperature wet-heat hydrolysis and biological drying can be combined. First, through a lower hydrolysis temperature and a longer hydrolysis time, the cell walls in the biomass waste are broken, the cell fluid flows out, and the moisture content of the material is reduced, which reduces the difficulty of subsequent dehydration. After the material is dehydrated, the moisture content is further reduced, so that the organic matter content of the material is greatly improved, thereby meeting the requirements of the solid content of the organic matter degradation itself in the biological drying step, and providing a reliable material basis for the biological drying step; at the same time, after the two steps of low-temperature wet-heat hydrolysis and dehydration, the decrease in moisture content can make the oxygen demand for drying and biodegradation in the biological drying process reach a basically balanced state. Without these two steps, the amount of air required for drying the material will be 10-30 times the oxygen demand for biodegradation, which will lead to industrial applicability. The temperature of the low-temperature wet-heat hydrolysis step is lower than that of the biological drying step by controlling the temperature of the two steps. This can avoid the problem of cooling down the biological drying step after high-temperature hydrolysis in the traditional process. The temperature of the low-temperature wet-heat hydrolysis step is similar to that of the biological drying step, which reduces the heat exchange of the material and enables the biological drying step to better utilize the heat attached to the material after it comes out of the low-temperature wet-heat hydrolysis step. Moreover, the organic matter in the material after mechanical sorting carries thermophilic bacteria, so part of it is refluxed to the biological drying step, so that the hydrolyzed material can be directly inoculated with thermophilic bacteria and thermophilic bacteria carried in the refluxed organic matter at the same time, thereby effectively degrading the organic matter and shortening the biological drying time from the conventional 4-12 days to 1.5 days to 2.5 days.

[0010] In one embodiment, the drying waste gas includes reflow waste gas and waste gas to be discharged, the drying gas includes reflow waste gas, the temperature of the drying gas is 75°C-85°C, the oxygen content of the drying air is 1-3 times the oxygen demand of the biological drying step, and the relative humidity of the drying gas is 8%-12%.

[0011] By adopting the above process, a part of the drying waste gas can be recycled, the scale of waste gas treatment is reduced, and the heat energy carried by the reflux waste gas is reasonably utilized; the drying gas including the reflux waste gas is made to reach the above temperature, oxygen content and relative humidity, which not only can provide the biological drying step with a suitable ventilation environment, but also can achieve better temperature and humidity control in the biological drying step, so that the organic matter in the biological drying step can be effectively degraded, and the heat generated during the degradation process can further reduce the water content of the material.

[0012] In one of the embodiments, the particle size of the material to be processed is ≤80 mm; the moisture content of the hydrolyzed material is 40%-50%; and the moisture content of the dehydrated material is 5%-15%.

[0013] By adopting the above particle size, the size of the material to be treated is suitable for the subsequent low-temperature wet heat hydrolysis step; through the two steps of low-temperature wet heat hydrolysis and dehydration, the material reaches the above moisture content, thereby meeting the solid content requirement for the degradation of organic matter itself in the biological drying step.

[0014] In one embodiment, the recycled materials consist of metals, heavy objects and other materials;

[0015] The mechanical sorting includes magnetic sorting and wind sorting, the magnetic sorting is used to sort metals, and the wind sorting is used to sort heavy objects.

[0016] Through the above-mentioned magnetic separation and wind separation, metals and heavy objects are separated from the biologically dried materials, so that the materials can be fully reused.

[0017] In one embodiment, the thermophilic bacteria include Bacillus subtilis, thermophilic actinomycetes or monosporic bacteria.

[0018] The present invention also provides a system for garbage sorting, which adopts the above process and includes: a crusher, a low-temperature hot and wet hydrolysis machine, a dehydrator, a biological dryer, and a mechanical sorting device connected in sequence, wherein the mechanical sorting device is connected to the biological dryer.

[0019] Through the above system, the garbage can be first broken into suitable particle sizes, and then undergo low-temperature hot and wet hydrolysis, dehydration, and biological drying treatment in sequence. Finally, the recyclable materials are sorted out through mechanical sorting. At the same time, some of the organic matter obtained after mechanical sorting is returned to enhance the effect of biological drying.

[0020] In one embodiment, the system further comprises a heating system, a deodorization system and a sewage collection system;

[0021] The heating system includes a mixer, a blower, a heat exchanger, and a steam engine. The mixer is in communication with the bio-drying machine, the mixer is in communication with the blower, the mixer is in communication with the heat exchanger, the steam engine is in communication with the heat exchanger, the steam engine is in communication with the low-temperature wet-heat hydrolysis machine, the heat exchanger is in communication with the low-temperature wet-heat hydrolysis machine, and the heat exchanger is in communication with the bio-drying machine.

[0022] The deodorization system comprises a spray device, a filter tank and a discharge device, the biological dryer is connected to the filter tank through the spray device, and the discharge device is connected to the filter tank;

[0023] The sewage collection system comprises a liquid storage tank, the liquid storage tank is connected to the low-temperature wet heat hydrolysis machine, the liquid storage tank is connected to the dehydrator, and the liquid storage tank is connected to the mixer.

[0024] The blower in the above-mentioned heating system introduces fresh air into the mixer, so that the fresh air and the reflux exhaust gas are mixed in the mixer, so that the oxygen content of the mixed gas meets the requirements, and then the mixed gas is introduced into the heat exchanger. The steam engine introduces steam into the heat exchanger, so that the temperature and humidity of the mixed gas meet the requirements, and the obtained dried gas is introduced into the biological dryer, so that the biological drying step has a suitable ventilation environment, suitable reaction temperature and humidity, so that the organic matter in the material can be effectively degraded.

[0025] In one embodiment, the mechanical sorting equipment includes a magnetic sorter and a wind sorter, the biological drying machine is connected to the magnetic sorter, the magnetic sorter is connected to the wind sorter, and the wind sorter is connected to the biological drying machine.

[0026] By adopting the above design, metals in the dried material can be separated out through magnetic separation for recycling; heavy materials in the dried material can be separated out through wind separation, leaving light materials containing organic matter, and part of the organic matter is used as reflux organic matter to enhance the organic matter degradation effect of the biological drying step, and the remaining part can be used as raw materials for various processes such as anaerobic thermal cracking.

[0027] In one embodiment, the crusher is provided with a material receiving device, and the material receiving device is used for material buffering; the low-temperature wet heat hydrolysis machine is provided with a stirring device, a shaftless screw conveying device and a drainage device, the crusher is connected with the drainage device through a slideway, the low-temperature wet heat hydrolysis machine is connected with the dehydrator through the shaftless screw conveying device, and the stirring device is used to stir the material to be processed;

[0028] The dehydrator is connected to the biological drying machine via a belt conveyor;

[0029] The biological drying machine is connected to the magnetic separator via a belt conveyor, and the magnetic separator is connected to the wind separator via a belt conveyor.

[0030] The above-mentioned material receiving device can facilitate material buffering and reduce the waiting time of vehicles transporting materials; the above-mentioned drainage device can drain the material first when it enters the low-temperature wet heat hydrolysis machine, reducing the energy consumption of subsequent processes; the above-mentioned slideway is used to connect the crusher and the drainage device, which can greatly reduce the frequency of maintenance and cleaning.

[0031] The present invention also provides a method for treating garbage, which uses the process to treat garbage, and the garbage includes biomass garbage.

[0032] The above process is used to treat biomass waste. In the low-temperature hot and wet hydrolysis step, there is no need to add reagents to adjust the pH value, which greatly reduces the deodorizer air volume. At the same time, biological drying is used to further reduce the moisture content in the material. By combining measures such as reflow inoculation of mechanically sorted organic matter, high-temperature aerobic composting with thermophilic bacteria, and heating and drying gas assistance, the time of the biological drying step is shortened from the traditional 4-12 days to 1.5-2.5 days.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The invention discloses a process for garbage sorting, a system and an application thereof. The process combines low-temperature wet-heat hydrolysis and biological drying processes, so that cells in biomass garbage are broken and cell fluid flows out, hydrolysis wastewater is obtained and removed, and the difficulty of subsequent dehydration is reduced. Compared with the existing high-temperature wet-heat hydrolysis, the process has the advantages of low operating temperature, no need to add reagents to adjust pH value, greatly reducing the air volume of the deodorizer, etc. Compared with the high-temperature wet-heat hydrolysis, the process energy consumption is reduced by 90%. In the biological drying step, the hydrolyzed garbage is directly inoculated with thermophilic bacteria and thermophilic bacteria carried in the refluxed organic matter to effectively degrade organic matter, and the heat generated in the degradation reaction process is used to further reduce the water content in the garbage, and finally solves the problem that the mixed garbage contains biomass garbage, which causes adhesion after corruption and cannot achieve effective mechanical sorting, thereby causing difficulty in resource utilization of the garbage. At the same time, due to the use of auxiliary measures such as reflux inoculation of organic matter obtained after mechanical sorting, high-temperature oxygen-consuming composting with thermophilic bacteria, and heating of drying gas, the time of the biological drying step is greatly shortened, and the material reduction after biological drying is about 50%. This process overcomes the shortcomings of traditional mechanical sorting processes for mixed garbage, such as complex routes, large equipment size, large footprint, high investment, high cleaning frequency, poor stability and low sorting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of a system for garbage sorting in Example 1.

[0036] Among them, 1 is a crusher, 2 is a low-temperature wet hot water hydrolysis machine, 3 is a dehydrator, 4 is a biological drying machine, 5 is a magnetic separator, 6 is a wind separator, 7 is a mixer 7, 8 is a blower, 9 is a heat exchanger, 10 is a steam engine, 11 is a filter tank, 12 is a discharge device, 13 is a liquid storage tank, and 14 is a spray device. DETAILED DESCRIPTION

[0037] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0040] definition:

[0041] The biomass waste mentioned in the present invention refers to the waste produced and consumed by humans in the process of utilizing biomass. It still belongs to the macroscopic category of biomass, but its energy density, availability, etc. are significantly reduced.

[0042] source:

[0043] Unless otherwise specified, the materials and parts used in this embodiment are all commercially available; the experimental methods are all conventional experimental methods in the art unless otherwise specified.

[0044] Example 1

[0045] A system and process for waste sorting.

[0046] 1. A system for sorting garbage, such as Figure 1 As shown, the system includes: a crusher 1, a low-temperature hot and wet hydrolysis machine 2, a dehydrator 3, a biological dryer 4, a magnetic separator 5, a wind separator 6, a heating system, a deodorization system and a sewage collection system.

[0047] The crusher 1, the low-temperature wet hot water hydrolysis machine 2, the dehydrator 3, the biological drying machine 4, the magnetic separator 5, and the wind separator 6 are connected in sequence, and the wind separator 6 is connected to the biological drying machine 4; the crusher 1 is provided with a material receiving device, and the volume of the material receiving device is about 20 cubic meters. The low-temperature wet hot water hydrolysis machine 2 is provided with a stirring device, a shaftless screw conveying device and a drainage device. The crusher 1 is connected to the water filtering device through a slideway, and the low-temperature wet hot water hydrolysis machine 2 is connected to the dehydrator 3 through a shaftless screw conveying device. The stirring device is used to stir the material in the low-temperature wet hot water hydrolysis machine 2. The dehydrator 3 is connected to the biological drying machine 4 through a belt conveyor, and the biological drying machine 4 is connected to the magnetic separator 5 through a belt conveyor, and the magnetic separator 5 is connected to the wind separator 6 through a belt conveyor.

[0048] The heating system includes a mixer 7, a blower 8, a heat exchanger 9 and a steam engine 10; the mixer 7 is connected to the biological dryer 4, the mixer 7 is connected to the blower 8, the mixer 7 is connected to the heat exchanger 9; the steam engine 10 is connected to the heat exchanger 9, the steam engine 10 is connected to the low-temperature wet heat hydrolysis machine 2; the heat exchanger 9 is connected to the low-temperature wet heat hydrolysis machine 2, and the heat exchanger 9 is connected to the biological dryer 4.

[0049] The deodorization system includes a spray device 14 , a filter tank 11 and a discharge device 12 . The biological dryer 4 is connected to the filter tank 11 through the spray device 14 . The spray device 14 is arranged between the biological dryer 4 and the filter tank 11 . The discharge device 12 is connected to the filter tank 11 .

[0050] The sewage collection system includes a liquid storage tank 13 , the liquid storage tank 13 is connected to the low-temperature wet-heat hydrolysis machine 2 , the liquid storage tank 13 is connected to the dehydrator 3 , and the liquid storage tank 13 is connected to the mixer 7 .

[0051] In this embodiment, the low-temperature wet-heat hydrolysis machine 2 is a low-temperature wet-heat hydrolysis tank, the dehydrator 3 is a screw extrusion dehydrator 3, and the discharge device 12 is a chimney.

[0052] 2. A process for sorting garbage.

[0053] The process includes the following steps:

[0054] 1. Low temperature and hot water hydrolysis and dehydration.

[0055] The garbage enters the crusher 1 and is crushed into materials to be treated with a particle size of ≤80 mm. The materials to be treated are introduced into the low-temperature wet-heat hydrolysis machine 2. The steam engine 10 introduces steam into the low-temperature wet-heat hydrolysis machine 2 to perform low-temperature wet-heat hydrolysis to obtain hydrolyzed materials and hydrolyzed wastewater. The temperature of the low-temperature wet-heat hydrolysis is 60° C. The time of the low-temperature wet-heat hydrolysis is 9h-12h, and the moisture content of the hydrolyzed materials is 45%;

[0056] The hydrolyzed material is introduced into the dehydrator 3 for dehydration to obtain dehydrated material and removed wastewater. The moisture content of the dehydrated material is 10%. The hydrolyzed wastewater and removed wastewater are discharged into the liquid storage tank 13.

[0057] 2. Biological drying.

[0058] The dehydrated material is biologically dried using drying gas, thermophilic bacteria and refluxed organic matter to obtain dried waste gas and dried material. The reaction temperature of biological drying is 70°C and the reaction time of biological drying is 2 days.

[0059] The dried exhaust gas is composed of the reflux exhaust gas and the exhaust gas to be discharged. The blower 8 blows the clean air into the mixer 7 to mix with the reflux exhaust gas to obtain a mixed gas and condensed water.

[0060] The condensed water is discharged into the liquid storage tank 13, and the mixed gas is introduced into the heat exchanger 9 to exchange heat with the steam introduced by the steam engine 10 to obtain dried gas and heated condensed water. The temperature of the dried gas is 80°C, the oxygen content is twice the oxygen demand of the biological drying step, and the relative humidity is 10%;

[0061] The dried gas is introduced into the biological drying machine 4 to promote the degradation of organic matter, and the heated condensed water is introduced into the low-temperature wet-heat hydrolysis machine 2 for auxiliary heating;

[0062] The exhaust gas to be discharged is sprayed by the spray device 14 and purified by the filter tank 11 before being discharged through the discharge device 12. In this embodiment, the spray treatment is acid-base spraying, and the filter tank 11 is a biological filter tank.

[0063] Mechanical sorting: The dried material is mechanically sorted. In the present embodiment, the mechanical sorting includes magnetic sorting and wind sorting. The magnetic sorting selects out the metal in the dried material, and the wind sorting selects out the heavy objects in the dried material. The remaining material includes organic matter, and a part of the organic matter is used as reflux organic matter and introduced into the biological drying machine 4 for the biological drying step.

[0064] The hydrolysis wastewater, removal wastewater and condensate discharged into the liquid storage tank 13 are treated and meet the discharge standards.

[0065] In this embodiment, the thermophilic bacteria include Bacillus subtilis, thermophilic actinomycetes or monosporic bacteria.

[0066] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A process for waste sorting, characterized in that: The process includes the following steps: Low-temperature wet-heat hydrolysis and dehydration: crush the garbage to obtain the material to be treated, perform low-temperature wet-heat hydrolysis on the material to be treated to obtain hydrolyzed material and hydrolyzed wastewater, dehydrate the hydrolyzed material to obtain dehydrated material and dehydrated wastewater; the temperature of the low-temperature wet-heat hydrolysis is 55°C-65°C, and the time of the low-temperature wet-heat hydrolysis is 9h-12h; the water content of the hydrolyzed material is 40%-50%; the water content of the dehydrated material is 5%-15%; Biological drying: using drying gas, thermophilic bacteria and reflux organic matter to biologically dry the dehydrated material to obtain dried waste gas and dried material; the reaction temperature of the biological drying is 65°C-75°C, and the reaction time of the biological drying is 1.5 days-2.5 days; the dried waste gas includes reflux waste gas and waste gas to be discharged, the drying gas includes reflux waste gas, the temperature of the drying gas is 75°C-85°C, the oxygen content of the drying gas is 1-3 times the oxygen demand of the biological drying step, and the relative humidity of the drying gas is 8%-12%; Mechanical sorting: Mechanically sort the dried materials to obtain recycled materials and reflux organic matter.

2. The process according to claim 1, characterized in that The particle size of the material to be processed is ≤80mm.

3. The process according to claim 1, characterized in that The mechanical separation includes magnetic separation and wind separation.

4. The process according to any one of claims 1 to 3, characterized in that The thermophilic bacteria include Bacillus subtilis, thermophilic actinomycetes or monosporic bacteria.

5. A system for sorting garbage, characterized in that: The system adopts the process described in any one of claims 1 to 4, and comprises: a crusher, a low-temperature hot and wet hydrolysis machine, a dehydrator, a biological dryer, and a mechanical sorting device connected in sequence, wherein the mechanical sorting device is connected to the biological dryer.

6. The system according to claim 5, characterized in that The system also includes a heating system, a deodorization system and a sewage collection system; The heating system includes a mixer, a blower, a heat exchanger, and a steam engine. The mixer is in communication with the bio-drying machine, the mixer is in communication with the blower, the mixer is in communication with the heat exchanger, the steam engine is in communication with the heat exchanger, the steam engine is in communication with the low-temperature wet-heat hydrolysis machine, the heat exchanger is in communication with the low-temperature wet-heat hydrolysis machine, and the heat exchanger is in communication with the bio-drying machine. The deodorization system comprises a spray device, a filter tank and a discharge device, the biological dryer is connected to the filter tank through the spray device, and the discharge device is connected to the filter tank; The sewage collection system comprises a liquid storage tank, the liquid storage tank is connected to the low-temperature wet heat hydrolysis machine, the liquid storage tank is connected to the dehydrator, and the liquid storage tank is connected to the mixer.

7. The system according to claim 5, characterized in that The mechanical sorting equipment includes a magnetic sorter and a wind sorter, the biological drying machine is connected to the magnetic sorter, the magnetic sorter is connected to the wind sorter, and the wind sorter is connected to the biological drying machine.

8. The system according to claim 7, characterized in that The crusher is provided with a material receiving device, and the material receiving device is used for material buffering; the low-temperature wet heat hydrolysis machine is provided with a stirring device, a shaftless screw conveying device and a drainage device, the crusher is connected with the drainage device through a slideway, the low-temperature wet heat hydrolysis machine is connected with the dehydrator through the shaftless screw conveying device, and the stirring device is used to stir the material to be processed; The dehydrator is connected to the biological drying machine via a belt conveyor; The biological drying machine is connected to the magnetic separator via a belt conveyor, and the magnetic separator is connected to the wind separator via a belt conveyor.

9. A method for treating garbage, characterized in that: The process according to any one of claims 1 to 4 is used to treat garbage, wherein the garbage includes biomass garbage.

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