CN114538733A

CN114538733A - System and method for separating municipal waste

Info

Publication number: CN114538733A
Application number: CN202210212751.4A
Authority: CN
Inventors: 俞健; 陈仁辉; 顾杰; 熊淼
Original assignee: Shanghai Goodman Separation Process Equipment Co ltd
Current assignee: Shanghai Goodman Separation Process Equipment Co ltd
Priority date: 2022-03-04
Filing date: 2022-03-04
Publication date: 2022-05-27

Abstract

The invention belongs to the technical field of solid waste treatment, and particularly relates to a system and a method for separating municipal waste. The method comprises the following steps: obtaining a waste stream, the waste stream being of a material type comprising: large sundries, broken stones, sand, organic matters and mud cakes; sorting the waste streams according to volume difference to screen out large pieces of impurities and broken stones; further sorting the waste stream by density difference to separate organic matter from sand; the remaining waste stream is concentrated and pressed to produce a mudcake for storage and transportation. The application selects the materials with certain economic benefit or easy disposal from the group consisting of the following materials through the difference of the volume and the density of various types of materials in municipal waste: large sundries, broken stones, sand, organic matters and mud cakes.

Description

System and method for separating municipal waste

Technical Field

The invention belongs to the technical field of solid waste treatment, and particularly relates to a system and a method for separating municipal waste.

Background

At present, two main treatment methods for municipal waste are available: direct landfill treatment; and (4) separating, recharging and filling for comprehensive treatment.

The direct landfill treatment method comprises the following steps: the landfill can adopt a single landfill mode or a mixed landfill mode. The municipal waste can be independently buried in the form of building a special sanitary landfill. When the special landfill conditions are not met, the waste and the garbage can be mixed and then buried in the original municipal solid waste landfill. The water content of the untreated municipal waste is between 80 and 95 percent, and the pH is about 8. If the landfill is directly carried out without treatment, not only the admission condition of a landfill site cannot be met, but also pollutants such as organic matters, pathogens, percolate and the like in the wastes can cause secondary pollution, thereby bringing about serious environmental problems.

Separation, recharge and landfill comprehensive treatment: the process is that collected sludge in the channel is primarily separated in a treatment station by means of sedimentation and the like, the separated coarse substances and settled sand are directly sent to a landfill for landfill, and the residual sludge is re-filled into a sewer. Although the secondary risk of the process to the environment is lower than that of direct landfill, part of organic matters are still attached to the surface of the gravel, and certain environmental influence is generated in the landfill.

Disclosure of Invention

In one aspect, the present invention provides a method of separating municipal waste by selecting economically beneficial or easily disposable materials from the group consisting of: large sundries, broken stones, sand, organic matters and mud cakes.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method of separating municipal waste comprising the steps of:

obtaining a waste stream, the types of materials involved in the waste stream including: large sundries, broken stones, sand, organic matters and mud cakes;

sorting the waste streams according to volume difference to screen out large pieces of impurities and broken stones;

further sorting the waste stream by density difference to separate organic matter from sand;

the remaining waste stream is concentrated and pressed to produce a mudcake for storage and transportation.

In some embodiments, the specific step of further sorting the waste stream by density difference to separate organics from sand comprises: settling after scrubbing is finished on the sand with the organic matters attached to the surface; separating sand and organic matters in the sedimentation substrate by a differential separation principle; and dehydrating the separated sand and organic matters, and storing and transporting.

In some embodiments, a primary cyclone is provided to separate the slurry from the sand and organic matter prior to and during the sorting process.

In some embodiments, the system further comprises a secondary cyclone, wherein the secondary cyclone is connected with the overflow port of the primary cyclone, and the graded particle size of the secondary cyclone is lower than that of the primary cyclone for recovering the superfine sand.

In some embodiments, the specific steps of concentrating and pressing the remaining waste stream to produce a mudcake for storage and transportation are: concentrating the muddy water collected in the sewage tank generated in the previous step; the intermediate water generated by concentration is conveyed to the outside or recycled to each separation working section; and squeezing the concentrated sludge to obtain a mud cake for storage and transportation.

In some embodiments, the size fraction distribution of each material is as follows: the size of the large sundries exceeds 30 mm; the size of the broken stone is between 2 and 30 mm; the particle size of the sand is between 0.005 and 2 mm; and the grain size of the superfine sand is between 0.01 and 0.15 mm.

On the other hand, the invention provides a system for separating municipal waste, which realizes the classification and recovery of the waste by combining the comprehensive application of separation equipment by adopting the method and has the characteristics of high efficiency, economy and environmental protection.

a system for separating municipal waste is used for realizing the method for separating the municipal waste, and comprises a second working section for separating organic matters and sand based on density difference, wherein the second working section comprises a primary cyclone A, a scrubbing machine, a sedimentation tank, a primary cyclone B, a chute, a dewatering screen and a circular vibrating screen which are communicated with the outlet end of the chute in sequence and are respectively used for dewatering fine sand and organic matters; the primary cyclone A and the primary cyclone B are used for separating sand from mud; the scrubbing machine is used for scrubbing sand with organic matters attached to the surface; the sedimentation tank is used for sedimentation separation of the washed mortar, and the bottom of the sedimentation tank contains sand and a small part of organic matters; the chute is used for differential separation of sand and a small part of organic matters.

In some technical schemes, the device also comprises a secondary cyclone, a fine mud sieve and a squeezer, wherein the downstream of the primary cyclone A and the downstream of the primary cyclone B are sequentially communicated; the fine sand output end of the secondary cyclone is communicated to a dewatering screen for recycling the ultra-fine sand; the sewage output end of the fine mud sieve is communicated to a sewage pool; the press is used to screen out further dewatering of the mud to produce a mudcake that is convenient for storage and transportation.

In some technical schemes, the device further comprises a first working section for screening out large sundries and broken stones based on volume difference, the first working section comprises a waste storage tank, a cleaning separator communicated with the waste storage tank and used for screening out the large sundries, and a classifying screen communicated with the cleaning separator and used for sorting the broken stones, a first output end of the classifying screen is communicated with a feed end of a first-stage cyclone A, a second output end of the classifying screen is communicated to a jigger and used for cleaning and removing organic matters attached to the surfaces of the broken stones, and an output end of the jigger is communicated with the dewatering screen and the circular vibrating screen.

In some technical schemes, the sludge treatment device further comprises a third working section for sludge water concentration and squeezing to generate a sludge cake, wherein the third working section comprises a thickener communicated with the sewage tank, a first output end of the thickener is communicated to a water return tank, the water return tank is provided with two outlets, the first outlet is communicated with a reuse water header pipe, and the second outlet is communicated with an outer drainage header pipe; and the second output end of the thickener is communicated to a tank to be pressurized, and the output end of the tank to be pressurized is communicated to the filter press.

The invention adopts the technical scheme and at least has the following beneficial effects:

1. selecting materials which have certain economic benefits or are easy to dispose from the group consisting of the following materials according to the difference of the volume and the density of each type of material in municipal waste: the building material comprises large sundries, broken stones, sand, organic matters and mud cakes, wherein the sand can be sold as a building material; the macadam can be used as a base material for paving the pavement; the organic matter can be used as the raw material for anaerobic fermentation; in addition, the preparation of the mud cakes facilitates the subsequent storage and transportation;

2. the waste is classified and recycled through the comprehensive application of the separation equipment, so that the total landfill amount of the waste is greatly reduced, the environmental protection pressure is reduced, and the treatment efficiency is improved; the recycled waste can be sold in the market to generate economic benefit, and can also be used for other purposes to realize economic value;

3. the material that this application was chosen all is through dehydration, has guaranteed that there is not sewage exosmosis in the transportation, influences road and sanitation, has reduced the production of landfill processing operation back filtration liquid simultaneously, avoids polluting groundwater and surrounding soil quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings and the reference numerals thereof used in the embodiments are briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a system for separating municipal waste according to an embodiment of the invention.

The notations in the figures have the following meanings:

material and logistics numbering:

1-a waste stream; 2-large sundries; 3-an organic substance; 4-sand; 5-mud cake; 6-reuse water; 7-external drainage;

equipment numbering:

10-a waste storage tank; 11-a grab bucket; 12-a screw conveyor; 13-cleaning a separator; 14-a grading sieve; 15-a second pump sump; 16-a jigger; 17-a first pump sump;

21-primary cyclone A; 22-a scrubbing machine; 23-a sedimentation tank; 24-a primary cyclone B; 25-a spiral chute; 26-circular vibrating screen; 27-dewatering screen; 28-secondary cyclone; 29-fine screening; 30-a press;

40-a sewage tank; 41-a thickener; 42-a tank to be pressurized; 43-a filter press; and 44-a water return tank.

Detailed Description

In order to make the technical features, objects and effects of the present invention more clearly understood, a detailed description of embodiments of the present invention will be given below with reference to the accompanying drawings.

It should be noted that the terms "first" and "second" are used herein for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "multi-stage, multi-layer" means at least two stages/layers, e.g., two stages/layers, three stages/layers, etc.; and the term "and/or" is intended to include any and all combinations of one or more of the associated listed items.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In one embodiment, the present application provides a system for separating municipal waste to sort out economically or easily disposable materials selected from the group consisting of: large sundries, broken stones, sand, organic matters and mud cakes.

The system comprises a first station for screening out large debris and crushed stone based on volume difference, the first station comprising a waste storage tank 10 for storing a collected municipal waste stream; a screw conveyor 12 for solid waste conveyance; a cleaning separator 13 for receiving the solid waste, cleaning and screening out large foreign matters; a classifying screen 14 for crushed stone classification communicating with the washing separator 13. The first output of this classifying screen 14 is used for exporting silt mixture commodity circulation, and the second output intercommunication of classifying screen 14 has jigger 16, and the first output intercommunication first pump pond 17 of jigger 16 forms the washing return circuit that is used for rubble surface to adhere to the organic matter and clears away, and the second output of jigger 16 communicates respectively and is used for the dry dewatering screen 27 of rubble, and is used for the circular sieve 26 that shakes of organic matter dehydration recovery.

In this embodiment, by selection of different mesh size grading equipment: cleaning and separating machine 13 and grading screen 14, sorting out massive sundries 2 and broken stones from municipal waste stream preferentially, piling up after dewatering, wherein the massive sundries 2 can be buried, because the organic matter and pathogen carried on the surface are cleaned and removed, the secondary pollution of the subsequent percolate after burying is effectively reduced, and the quality of underground water source and soil is protected; the recycled macadam can be used as a basic material for paving the pavement, so that the economic value of the macadam is realized.

The system also comprises a second working section for sorting organic matters and sand based on density difference, wherein the second working section comprises a primary cyclone A21, a scouring machine 22, a sedimentation tank 23, a primary cyclone B24, a spiral chute 25, a dewatering screen 27 and a circular vibrating screen 26 which are communicated to the outlet end of the spiral chute and are respectively used for dewatering fine sand and organic matters; the primary cyclone A21 and the primary cyclone B24 are used for separating sand from mud; the scrubbing machine 22 is used for scrubbing sand with organic matters attached to the surface; the sedimentation tank 23 is used for standing and separating the scrubbed mortar, and layering the scrubbed mortar in the sedimentation tank according to the density difference between organic matters and sand, wherein the upper layer contains most of the organic matters, and the lower layer contains sand and a small amount of the organic matters; the spiral chute 25 separates sand and a small amount of adhered organic matter based on the differential separation principle, and stores the separated sand and the small amount of adhered organic matter after dehydration.

In the embodiment, organic matters carried on the surface of the sand are efficiently removed through the scrubbing machine 22, only a small amount of the organic matters are adhered to the surface and enter the spiral chute 25 together for differential separation, so that the classified recovery of the sand 4 and the organic matters 3 is realized, and the obtained sand material can be sold as building materials, so that the economic benefit is realized; while the organic matter 3 can be used as a raw material for anaerobic fermentation. This application is cleaned quick, the abundant recovery of organic matter and sand through the efficient and is realized to quick, the abundant recovery of quick, spiral chute gravity classification equipment of high accuracy, and economic benefits is outstanding, has greatly reduced the landfill total amount of discarded object, has alleviateed the environmental protection pressure, has improved the treatment effeciency.

In a preferred embodiment, the second station is also used for the recovery of ultra-fine sand, and comprises a secondary cyclone 28 connected in series downstream of the primary cyclone A21 and the primary cyclone B24, the graded size of the secondary cyclone 28 being lower than that of the primary cyclone, and the fine sand output end of the secondary cyclone 28 being connected to the dewatering screen 27 for the recovery of ultra-fine sand. The overflow end of the secondary cyclone 28 is connected to a fine mud screen 29, the sewage output end of the fine mud screen 29 is connected to a sewage pool 40, and the mud output end of the fine mud screen 29 is connected to a squeezer 30 for further dewatering to form a mud cake 5 for storage and transportation.

The recovery of superfine sand is realized through the series connection of two-stage swirler in this embodiment to utilize dewatering screen 27 to deviate from most moisture in the superfine sand thick liquid after the concentration, the output is fit for the superfine sand of stacking, and the graduation of building sand can be optimized to the superfine sand of retrieving, reduces the fineness modulus, so that the better concrete material of output compactness, durability.

The system also comprises a third working section for producing mud cakes by concentrating and squeezing mud water, wherein the third working section comprises a thickener 41 communicated with the sewage tank 40, a first output end of the thickener 41 is communicated to a water return tank 44, the water return tank 44 is provided with two outlets, the first outlet is communicated with a reuse water header pipe, and the second outlet is communicated with an outer drainage header pipe; the second output end of the thickener 41 is communicated to the tank 42 to be pressurized, and the output end of the tank 42 to be pressurized is communicated to the filter press 43.

In the embodiment, the mud cake 5 is prepared by arranging the concentration squeezing equipment aiming at the sewage recovered in each process, so that convenience is provided for subsequent storage and transportation, and the condition that the sewage seeps outwards in the transportation process to influence the road and environmental sanitation is ensured; and the intermediate water produced in the process can be used for conveying to the outside or recycling to each separation section.

In the embodiment, the waste is classified and recycled through the comprehensive application of the separation equipment, and the separation equipment has the characteristics of high efficiency, economy and environmental protection.

In another embodiment, the present application provides a method for separating municipal waste, which is applied to the above system for separating municipal waste, and the waste material and the classification particle size are specifically: large impurity blocks greater than or equal to 30mm, crushed stone 2-30mm, sand 0.005-2mm, superfine sand 0.01-0.15mm, and organic matter and mud cake.

In order to achieve the above purpose, the method adopted by the present application specifically comprises the following steps:

s10: a waste stream 1 is obtained, and the waste stream 1 is collected and stored in a waste storage tank 10 by each municipal project.

S20: the waste stream 1 is sorted by volume difference to screen out large debris 2 and crushed stone.

Step S20 specifically includes:

s21: the waste is sent into a spiral conveyor 12 through a grab bucket 11, the waste is evenly sent into a cleaning separator 13 by the spiral conveyor 12, the waste in the cleaning separator 13 is fully scattered and evenly stirred, and large impurities 2 are separated by a 30mm sieve basket arranged at an outlet position and stacked;

s22: materials with the particle size of more than 2mm in the cleaning separator 13 are sent to a cleaning loop formed by a jigger 16 and a first pump pool 17 to remove organic matters, and are discharged through a dewatering screen to be piled as broken stones; the materials with the diameter less than or equal to 2mm enter the second pump pool 15 for storage.

S30: the waste stream is further sorted by density difference to separate organic 3 from sand 4.

Step S30 specifically includes:

s31: the materials stored in the second pump pool 15 are pumped into a primary cyclone A21 to carry out primary separation of sand and mud, the separated sand is sent into a scrubbing machine 22 to be fully rubbed and cleaned, most of grease and iron oxide on the surface of the sand are removed, the scrubbed sand is sent into a sedimentation pool 23 to be layered, and the bottom of the sedimentation pool contains sand and a small amount of adhered organic matters;

s32: pumping the mortar stored in the settling tank into a primary cyclone B24 for separating sand from mud again, feeding the separated mortar into a spiral chute 25, and separating sand 4 and organic matters 3 at a differential speed according to the density difference of the organic matters attached to the surfaces of the sand and the sand;

s33: the separated sand is sent into a dewatering screen 27 for dewatering and stacking, the separated organic matter is sent into a circular vibrating screen 26 for dewatering and stacking, and sewage generated in the process is gathered into a sewage pool 40 for storage.

In a preferred embodiment, the method further comprises the steps of:

s34: and the mud water separated by the primary cyclone is sent into a secondary cyclone 28 for separating superfine sand, the grading granularity of the secondary cyclone 28 is 0.01-0.15mm, the separated superfine sand is dehydrated and recovered by a dehydration screen 27, and the clay with the particle size smaller than 0.01mm is conveyed to an arc-shaped fine mud screen 29 and a screw press by an overflow port of the secondary cyclone 28 for dehydration respectively and then is stored.

S40: the slurry collected in the lagoon 40 is concentrated and pressed to produce a mudcake 5 for storage and transportation.

The specific steps of S40 include:

s41: the muddy water in the sewage tank 40 is conveyed into a thickener 41 through a submersible pump for sludge concentration;

s42: the intermediate water generated by concentration enters a water return pool 44 for storage, the reuse water 6 is conveyed to each separation section through a reuse water header pipe communicated to the water return pool, and the external drainage 7 is conveyed to the outside through an external drainage header pipe communicated to the water return pool;

s42: the concentrated slurry is sent to a tank 42 to be pressed for storage, and is sent to a filter press 43 through a press pump to be pressed out of a mud cake 5 for storage and transportation.

The application selects materials with certain economic benefit or easy disposal from the group consisting of the following materials according to the difference of the volume and the density of various types of materials in municipal waste: the building material comprises large sundries, broken stones, sand, organic matters and mud cakes, wherein the sand can be sold as a building material; the macadam can be used as a base material for paving the pavement; the organic matter can be used as the raw material for anaerobic fermentation; in addition, the preparation of the mud cake provides convenience for subsequent storage and transportation.

According to the method, the recovery rate of 10-150um ultrafine sand is more than 90% through the series connection of the two stages of cyclones, the grading of the construction sand can be optimized through the ultrafine sand obtained through recovery, the fineness modulus is reduced, and finally concrete with better compactness and durability is produced.

The material that this application was chosen has all carried out dehydration, has guaranteed that there is not sewage exosmosis in the transportation, influences road and sanitation, has reduced the production of landfill processing operation back filtration liquid simultaneously, avoids polluting groundwater and soil quality on every side.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A method of separating municipal waste, comprising the steps of:

obtaining a waste stream, the waste stream being of a material type comprising: large sundries, broken stones, sand, organic matters and mud cakes;

2. A method of separating municipal waste according to claim 1, wherein the step of further sorting the waste stream by density difference to separate organic matter from sand comprises:

settling after scrubbing is finished on the sand with the organic matters attached to the surface;

separating sand and organic matters in the sedimentation substrate by a differential separation principle;

and dehydrating the separated sand and organic matters, and storing and transporting.

3. The method of separating municipal waste according to claim 2, wherein the municipal waste is further processed by the step of,

the first-stage cyclones are respectively arranged before and during the sorting treatment of the sand and the organic matters to separate mud and water.

4. The method of separating municipal waste according to claim 3, wherein the municipal waste is further processed by the step of,

also comprises a secondary cyclone which is provided with a cyclone body,

the secondary cyclone is connected with an overflow port of the primary cyclone, and the grading granularity of the secondary cyclone is lower than that of the primary cyclone and is used for recycling the superfine sand.

5. The method of claim 1, wherein the concentrating and pressing of the remaining waste stream to produce a mudcake for storage and transportation comprises:

concentrating the muddy water collected in the sewage tank generated in the previous step;

conveying the intermediate water generated by concentration to the outside or recycling the intermediate water to each separation section;

and squeezing the concentrated sludge to obtain a mud cake for storage and transportation.

6. A method of separating municipal waste according to any one of claims 1 to 5, wherein the size fraction distribution of each material is as follows:

the size of the large sundries exceeds 30 mm; the size of the broken stone is between 2 and 30 mm; the particle size of the sand is between 0.005 and 2 mm; and the grain size of the superfine sand is between 0.01 and 0.15 mm.

7. A system for separating municipal waste, characterized in that it is used for realizing a method for separating municipal waste according to any one of claims 1 to 5, the system comprises a second section for separating organic matter and sand based on density difference, the second section comprises a primary cyclone A, a scrubber, a settling tank, a primary cyclone B, a chute and a dewatering screen and a circular vibrating screen which are communicated with the outlet end of the chute in sequence and are used for dewatering fine sand and organic matter respectively;

the primary cyclone A and the primary cyclone B are used for separating sand from mud;

the scrubbing machine is used for scrubbing sand with organic matters attached to the surface;

the sedimentation tank is used for sedimentation separation of the washed mortar, and the bottom of the sedimentation tank contains sand and a small part of organic matters;

the chute is used for differential separation of sand and a small part of organic matters.

8. The system for separating municipal waste according to claim 7, further comprising a secondary cyclone, a fine screen and a press in sequential communication downstream of the primary cyclone A and the primary cyclone B;

the fine sand output end of the secondary cyclone is communicated to a dewatering screen for recycling the ultra-fine sand;

the sewage output end of the fine mud sieve is communicated to a sewage pool;

the press is used to screen out further dewatering of the mud to produce a mudcake that is convenient for storage and transportation.

9. The system for separating municipal waste according to claim 7, further comprising a first section for screening out large debris and crushed stone based on volume difference, wherein the first section comprises a waste storage tank, a cleaning separator for screening out large debris communicated with the waste storage tank, and a classifying screen for sorting crushed stone communicated with the cleaning separator, a first output end of the classifying screen is communicated with a feed end of the primary cyclone A, a second output end of the classifying screen is communicated to a jigger for cleaning and removing organic matters attached to the surface of crushed stone, and an output end of the jigger is communicated with the dewatering screen and the circular vibrating screen.

10. The system for separating municipal waste according to claim 7, further comprising a third section for compressing and concentrating the sludge to produce a cake, wherein the third section comprises a thickener communicated with the wastewater tank, a first output end of the thickener is communicated to a water return tank, the water return tank is provided with two outlets, a first outlet is communicated with a reuse water header pipe, and a second outlet is communicated with an outer discharge water header pipe; and the second output end of the thickener is communicated to a tank to be pressurized, and the output end of the tank to be pressurized is communicated to the filter press.