WO2016112735A1

WO2016112735A1 - System for co-processing household solid waste in cement kiln and method thereof

Info

Publication number: WO2016112735A1
Application number: PCT/CN2015/093993
Authority: WO
Inventors: 贲道春; 查文炜; 王复光; 王家安; 曹卫; 倪文龙
Original assignee: 江苏鹏飞集团股份有限公司
Priority date: 2015-01-14
Filing date: 2015-11-06
Publication date: 2016-07-21
Also published as: CN104550201B; CN104550201A

Abstract

A system for co-processing household solid waste in a cement kiln and method thereof, the system comprising a drying device (2), a waste storage container (6), a pyrolysis furnace (14), a residue cooling device and a cement kiln system; the drying device (2) is in communication with the waste storage container (6); a gas inlet of the drying device (2) is in communication with a gas outlet of a grate cooler (18) of the cement kiln system; a gas outlet of the drying device (2) is in communication with a gas inlet of the grate cooler (18); the waste storage container (6) is in communication with a gas inlet of the pyrolysis furnace (14) and the gas inlet of the grate cooler (18) respectively; a gas outlet of the pyrolysis furnace (14) is in communication with a gas inlet of a cement kiln decomposition furnace (16); a residue outlet of the pyrolysis furnace (14) is in communication with the residue cooling device. The system dries waste first before pyrolyzing the waste, consumes less heat during pyrolysis, saves energy, and a pyrolysis gas thereof has a high heat value and a fast heat release speed; gas between the drying device (2) and the grate cooler (18) is recycled, saving energy; air from the pyrolysis furnace (14) and the grate cooler (18) is from the waste storage container, forms a negative pressure and effectively prevents harmful gas from leaking; a part of products of the pyrolysis furnace are recycled in the furnace, thus reducing heat loss, and improving heat efficiency of the pyrolysis furnace.

Description

Cement kiln cooperative treatment domestic garbage system and method thereof

Technical field

The present application relates to the field of garbage disposal, and in particular to the field of cement kiln co-processing of domestic garbage.

Background technique

The existing domestic garbage disposal methods mainly include: landfill method, direct incineration method, incineration power generation method and cement kiln co-processing method. The basic principle of the cement kiln co-processing method is to burn garbage, generate heat by the heat generated by waste combustion, send the pyrolysis gas as fuel to the cement kiln decomposition furnace, and use the burned residue as cement raw material to feed the cement raw material mill. .

The existing cement kiln co-processing method is to directly pick up the garbage from the garbage storage and send it to the pyrolysis furnace. There are the following deficiencies in the process:

1. The garbage in the garbage storage has a high water content, and the specific heat capacity of the water is large. Therefore, a large amount of heat energy is consumed in the waste pyrolysis process, and the temperature in the pyrolysis furnace is not easily increased due to excessive moisture, and the pyrolysis speed is slow and hot. The calorific value of degassing is very low;

2. In addition to the conventional air components such as oxygen and nitrogen, the air in the library also contains more harmful gases generated by domestic garbage. Since the garbage storage is not completely closed, harmful gases are easily spilled and affect the surrounding environment;

3. The porosity of the residue of the pyrolysis furnace is relatively large, which makes the discharge end of the discharge end poor, and the risk is high;

4. The solids produced by the pyrolysis furnace are all cooled out of the furnace, taking away more heat. After the garbage enters the pyrolysis furnace, it needs to start heating from a lower temperature, and the heat efficiency is low.

Summary of the invention

The main technical problem to be solved by the present application is to provide a method for co-processing domestic garbage by cement kiln and a collaborative treatment of domestic garbage system with cement kiln.

The technical solution of the present invention is implemented in the following manner:

A cement kiln co-processing method for domestic garbage, comprising the following steps:

a. Drying the domestic garbage in the garbage storage;

b. Pyrolysis of the domestic garbage after the drying in step a;

c. The pyrolysis gas and residue generated in step b are reused;

The heat source part/all of the drying device in the above step a is the hot exhaust gas generated by the grate cooler, and the gas for cooling in the grate cooler includes the cold tail gas of the drying device and the gas in the garbage bin.

The cement kiln co-processing the domestic garbage method, in step b, the oxygen portion required for pyrolysis Or all from the gas in the garbage store;

The cement kiln cooperates with the domestic garbage method. In the step b, the raw material for pyrolysis is a mixture of domestic garbage and fine slag; the domestic garbage has been dried in step a; the fine slag is a part of the product after the pyrolysis in step b.

The cement kiln cooperates with the domestic garbage method. In the step c, the pyrolysis gas is used as a fuel, and the residue is classified and recycled after being cooled and screened.

The cement kiln cooperates with the domestic garbage method, and the domestic garbage in the step a is subjected to a crushing process before drying.

A cement kiln co-processing a domestic garbage system, comprising a drying device, a garbage storage, a pyrolysis furnace, a residue cooling device and a cement kiln; the drying device is connected with the garbage storage; the gas inlet of the drying device and the kiln of the cement kiln The gas outlet of the cold machine is connected; the gas outlet of the drying device is in communication with the gas inlet of the grate cooler; the air inlet of the pyrolysis furnace is in communication with the garbage storage; the air inlet of the grate cooler is connected to the garbage storage; the heat is The gas outlet of the unheating furnace is in communication with the air inlet of the cement kiln decomposition furnace; the residue outlet of the pyrolysis furnace is in communication with the residue cooling device.

The cement kiln cooperates with the domestic garbage system, and the pyrolysis furnace further comprises a rotary screen, the rotary screen inlet is connected with the pyrolysis tube outlet of the pyrolysis furnace; and the rotary screen is provided with a connection with the inlet of the pyrolysis cylinder. An outlet and a second outlet in communication with the residue cooling device.

The cement kiln cooperates with the domestic garbage system, and the above-mentioned residue cooling device includes a vibrating screen, a fine sand and a cooler; the fine sand is circulated in the vibrating screen and the cooler through the hoist.

The above cement kiln co-processes the domestic garbage system, and a crusher is also arranged between the garbage storage and the drying equipment.

The cement kiln cooperates with the domestic garbage system, and the garbage storage comprises a wet garbage storage connected with the inlet of the drying equipment and a dry garbage storage connected with the outlet of the drying equipment; the air inlet of the wet garbage storage and the pyrolysis furnace and the raft The air inlets of the cold machine are all connected; the dry garbage storage is connected to the inlet of the pyrolysis furnace.

The beneficial effects of the present invention are as follows:

1. Before the garbage is pyrolyzed, the drying and dehydration are carried out first, and the heat is consumed during the pyrolysis, the energy is saved, the pyrolysis gas generated during the pyrolysis is high, and the heat is released quickly;

2. Gas recycling between drying equipment and grate cooler to save energy;

3. The air of the pyrolysis furnace and the grate cooler comes from the garbage storage, so that the garbage reservoir forms a negative pressure, effectively preventing the harmful gas overflow in the garbage storage;

4. Some products of the pyrolysis furnace circulate in the furnace to reduce heat loss and improve the thermal efficiency of the pyrolysis furnace;

5. Mix the fine sand and the hot residue to cool it, reduce the slag void in the pyrolysis furnace, and lock Wind effect.

DRAWINGS

1 is a flow chart of a method for co-processing domestic garbage in a cement kiln of the present application;

Figure 2 is a schematic block diagram of the internal structure of the pyrolysis furnace of the present application;

3 is a schematic structural view of a cement kiln co-processing domestic garbage system of the present application.

In the above Figures 1 and 2, the thick solid line represents the direction of the solid, and the dashed line with the arrow represents the direction of the gas.

In the above-mentioned Figures 1-3, 1 fan; 2 drying equipment; 3 spiral reamer; 4 gas pipeline; 5 board feeding machine; 6 garbage storage; 7 grab; 8 silo; 9 crusher; 11 board feeding machine; 12 spiral reamer; 13 pyrolysis gas pipeline; 14 pyrolysis furnace; 15 gas pipeline; 16 cement kiln decomposition furnace; 17 cement kiln, 18 篦 cooler; 19 fan; 20 hot air pipeline; Pipeline; 22 iron remover; 23 scrap iron store; 24 waste residue store; 25 zipper machine; 26 vibrating screen; 27 fan; 28 feed pipe; 29 hoist; 30 overflow pipe; 31 cooler; 32 screw reamer; Lifting machine; 34, rotary screen; 35, pyrolysis cylinder.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings.

As shown in FIG. 3, the cement kiln of the present invention co-processes the domestic garbage system, including the drying equipment 2, the garbage storage 6, the pyrolysis furnace 14, the residue cooling equipment and the cement kiln system; the garbage storage 6 includes the wet garbage storage and the dry garbage. The library (not shown in Fig. 3, see Fig. 1), the wet garbage storage is connected to the inlet of the drying device 2, and the dry garbage storage is connected to the outlet of the drying device 2, and between the two is provided for controlling the entry and exit of materials. The spiral reamer 3; the dry garbage storage and the wet garbage storage are independent of each other to ensure that the dried garbage in the dry garbage storage does not become wet again. The dry refuse storage and pyrolysis furnace 14 are connected by a plate feeder 11 and control the amount of feed of the pyrolysis furnace 14 by a helical reamer 12. The residue cooling device includes a vibrating screen 26 and a cooler 31 that uses fine sand as a cooling medium, and the fine sand realizes circulation between the vibrating screen 26 and the cooler 31 through the hoisting machine 29, the hoisting machine 33, and the spiral reamer 32. The residue outlet of the pyrolysis furnace 14 is the discharge pipe 28, and the discharge pipe 28 is in communication with the vibrating screen 26. The vibrating screen 26 is in communication with the iron remover 22 via a zipper 25, and the outlet of the iron remover 22 is connected to the scrap iron bin 23 and the waste sump 24, respectively. The residue after the screening of the vibrating screen 26 is recovered by the iron slag separated by the iron remover 22 and enters the scrap iron storage tank 23, and the waste slag enters the waste sump 24 for use, and the cement raw material mill is sent as a cement raw material.

In Fig. 3, the cement kiln co-processing domestic garbage system further comprises a crusher 9 connected to the garbage storage 6, the entrance of the drying device 2 is provided with a plate feeding machine 5, the grab 7 can be in the garbage storage 6, the plate feeding machine 5, and the broken Machine 9 material The magazine 8 moves between the silo 8 and the silo 10 of the pyrolysis furnace 14. The working mode of the grab 7: a. The garbage in the wet garbage storage of the garbage collection 6 is put into the silo 8, and then enters the crusher 9 to be broken, and finally returns to the garbage storage 6 for use or enters the board feeding machine 5. b. Grab the crushed wet garbage in the garbage storage 6 and put it into the board feeding machine 5. The wet garbage enters the drying equipment 2 through the board feeding machine 5 and then returns to the dry garbage storage of the garbage storage 6 via the spiral reamer 3. c. Grab the dry garbage in the dry garbage storage and put it into the silo 10, and the dry garbage enters the pyrolysis furnace 14 to be pyrolyzed by the plate feeding machine 11 and the spiral reamer 12.

As shown in FIG. 3, an overflow pipe 30 is further provided between the vibrating screen 26 and the zipper 25. The fine sand in the cooler 31 enters the lowering pipe 28 through the spiral reamer 32 and the hoist 33, and further enters the vibrating screen 26. In this way, the fine sand is mixed with the hot residue at the outlet of the decomposition furnace 14 to cool it, and on the other hand, it acts as a lock-up to avoid pyrolysis gas escape pollution. After the sieve 26 is sieved, the fine sand is returned to the cooler 31 through the hoisting machine 29 to complete the circulation. The fine sand is cooled by the cooler 31 for reuse. Since the hot residue at the outlet of the decomposition furnace 14 is doped with a part of fine slag (which can be used as fine sand), when the fine sand in the cooler 31 is excessive, the excess fine sand forms overflow sand, and enters the zipper 25 through the overflow pipe 30. .

As shown in FIG. 2, a rotary screen 34 is further provided in the pyrolysis furnace 14, and the inlet of the rotary screen 34 is connected to the outlet of the pyrolysis cylinder 35 of the pyrolysis furnace 14. The rotary screen 34 is provided with a first outlet communicating with the inlet of the pyrolysis cylinder 35 and a second outlet communicating with the residue cooling device. The second outlet is connected to the vibrating screen 26 through a discharge tube 28. During operation, the dry waste sent to the pyrolysis furnace 14 through the plate feeder 11 and the helical reamer 12 enters the pyrolysis cylinder 35 for pyrolysis. The residue discharged from the outlet of the pyrolysis cylinder 35 enters the rotary screen 34 for screening. According to the setting of the rotary screen 34, the residue is sieved to form finer fine particles and large hot residue of the particles. The fine slag is returned to the inlet of the pyrolysis cylinder 35 through the first outlet of the rotary sieve 34, mixed with the dry garbage, and then re-entered into the pyrolysis cylinder for pyrolysis; the larger hot residue of the pellet passes through the second outlet of the rotary sieve 34 and enters the lowering pipe. 28 exits the pyrolysis furnace 14. The fine slag is mixed with the incoming garbage as a solid heat carrier, one can make the garbage heat up rapidly and improve the heating efficiency; Secondly, because the same volume of fine slag has a larger heat capacity than the hot residue, preferentially discharging the hot residue can effectively reduce the heat loss in the furnace. Energy saving.

As shown in Figure 3, the gas recycling process in the system is as follows:

1. The garbage storage 6 is connected to the pyrolysis furnace 14 through the gas pipe 15, and the gas in the garbage storage 6 is driven by the fan 27 into the pyrolysis furnace 14, the direction of the gas flow in the pyrolysis furnace 14 and the direction of the garbage in the pyrolysis furnace 14. Inverse. In this way, one can ensure that the gas first contacts the garbage with higher temperature, heats up as soon as possible, and improves the heat efficiency; secondly, the gas per unit volume is exposed to the garbage as much as possible to ensure sufficient oxygen to fully burn the garbage; The harmful gas can be flushed out of the pyrolysis furnace with the pyrolysis residue, causing environmental pollution.

2. The garbage storage 6 and the grate cooler 18 are connected through the exhaust gas pipe 21; there is a waste gas in the exhaust gas pipe 21 The cooler 6 and the cooler gas of the drying apparatus 2, the gas being driven by the fan 19 enters the grate cooler 18 to provide a source of cold for the grate cooler 18.

3. The fan 1 is disposed at the air outlet end of the drying device 2, and can prevent the gas from the garbage storage 6 from being reversely entered into the drying device 2.

4. The drying device 2 is connected to the grate cooler 18 of the cement kiln system through a hot air duct 20. The grate cooler 18 operates to produce hot exhaust gas that enters the drying device 2 through the hot air duct 20 to provide a source of hot air for the drying device 2 to operate.

5. The gas discharged from the pyrolysis furnace 14 (mainly pyrolysis gas and gas from the garbage storage 6 and subjected to high temperature treatment by the pyrolysis furnace 14) is supplied to the cement kiln decomposition furnace 16 as a fuel.

Through such gas circulation, partial energy reuse between the grate cooler 18 and the drying device 2 greatly reduces the demand for additional energy, reduces the emission of high temperature gas, and truly saves energy and protects the environment; The oxygen required for the grate cooler 18 and the pyrolysis furnace 14 is realized by extracting the air in the garbage storage 6, so that the garbage storage 6 can ensure a certain negative pressure, thereby avoiding the overflow of harmful gases in the garbage storage 6 and reducing personal safety.

The cement kiln provided by the invention cooperates with the method of treating domestic garbage, including three steps of drying, pyrolysis and recycling. The specific processing steps are shown in Figure 1: a. The raw garbage in the wet garbage (collected by garbage collection tools such as garbage trucks) is broken by the grab 7 into the crusher 9, and then dried by the plate feeder 5. The equipment 2 is dried; the dried garbage after drying is passed through the spiral reamer 3 (locked spiral spiral) into the dry garbage storage for use. b. The dry garbage in the dry garbage storage is sequentially pyrolyzed through the grab 7, the plate feeder 11, the spiral reamer 12 and the pusher spiral into the pyrolysis furnace 14. c. The hot residue after pyrolysis enters the vibrating screen 26 for cooling and sieving, and then enters the iron remover 22 through the zipper 25; the scrap iron generated by the iron remover 22 enters the scrap iron store 23 for recycling and reuse, and the waste residue generated by the iron remover 22 Then enter the waste sump 24 for temporary storage; then the waste slag enters the cement raw material mill as cement raw material and cement raw material for production. The cement raw material treated by the cement raw material mill is processed into the cement kiln 17 by the cement kiln decomposition furnace 16, and the product of the cement kiln 17 is then cooled into the grate cooler 18.

According to the gas circulation shown in Fig. 1, the heat source of the drying device 2 in the step a is the hot exhaust gas generated by the grate cooler 18, and the gas for cooling in the grate cooler 18 includes the cold tail gas and the garbage bin of the drying device 2. Gas within 6. In step b, the gas required for the pyrolysis furnace 14 also comes from the garbage reservoir 6. In the step c, the pyrolysis gas generated by the pyrolysis furnace 14 is used as a fuel to enter the cement kiln decomposition furnace 16. In this way, the partial energy reuse between the grate cooler 18 and the drying device 2 greatly reduces the demand for additional energy, reduces the emission of high temperature gas, and truly saves energy and protects the environment; And pyrolysis furnace 14 The required oxygen is realized by extracting the air in the garbage storage 6, so that the garbage storage 6 can ensure a certain negative pressure, and the harmful gas overflow in the garbage storage 6 is avoided, thereby reducing personal safety.

As shown in Fig. 2, the pyrolysis in the pyrolysis furnace 14 is carried out according to the following procedure: the material to be pyrolyzed (mixture of dry waste and fine slag) enters the pyrolysis furnace 14, passes through the rotary sieve after pyrolysis in the pyrolysis cylinder 35 34 sieves the finer fine particles and the larger thermal residues of the particles. The fine slag is returned to the pyrolysis furnace 14 at the inlet and mixed with the dry waste, and the hot residue is discharged from the pyrolysis furnace 14. In the step b, the raw material for pyrolysis is a mixture of domestic garbage and fine slag; the above domestic garbage has been dried in the step a; the fine slag is a part of the product after the pyrolysis in the step b. Part of the pyrolysis product of the pyrolysis furnace 14 circulates inside the furnace to increase the heating rate in the furnace and avoid heat loss.

Also shown in Fig. 1 is a detailed step of cooling the hot residue: the hot residue from the pyrolysis furnace 14 is mixed with the cold fine sand lifted by the hoist 33, the hot residue is cooled by the cold fine sand, and the vibrating screen is After sieving in 26, the sieved hot fine sand is returned to the cooler 31 through the hoisting machine 29, and the hot fine sand is cooled by the cooler 31; the cooled fine sand is again introduced into the hoist 33 to complete the circulation. The excess fine sand in the cooler 31 forms overflow sand and is discharged into the zipper. Fine sand is used as a cooling medium, and it is mixed with hot residue at the outlet of the pyrolysis furnace 14, which can effectively lock the air.

In summary, the present invention performs drying and dehydration prior to waste pyrolysis, consumes less heat during pyrolysis, saves energy, generates high heat of pyrolysis gas during pyrolysis, and exotherms quickly; drying equipment and grate cooler The gas is recycled to save energy; the air of the pyrolysis furnace and the grate cooler comes from the garbage storage, so that the waste reservoir forms a negative pressure, effectively preventing the harmful gas from overflowing in the garbage storage; some products of the pyrolysis furnace are circulated in the furnace, reducing Heat loss, improve the thermal efficiency of the pyrolysis furnace; use fine sand as the cooling medium to reduce the slag voids in the pyrolysis furnace and play a role of locking the wind.

The above is a further detailed description of the present invention in connection with the specific embodiments, and the specific embodiments of the present invention are not limited to the description. A number of simple derivations or substitutions may be made by those skilled in the art without departing from the inventive concept.

Claims

A cement kiln co-processing method for domestic garbage, characterized in that the method comprises the following steps:

a. Drying the domestic garbage in the garbage storage;

b. Pyrolysis of the domestic garbage after the drying in step a;

c. The pyrolysis gas and residue generated in step b are reused;

The heat source part/all of the drying device in the above step a is the hot exhaust gas generated by the grate cooler, and the gas for cooling in the grate cooler includes the cold tail gas of the drying device and the gas in the garbage bin.
The method for co-processing domestic garbage in a cement kiln according to claim 1, wherein in the step b, part or all of the oxygen required for pyrolysis heat is from a gas in the garbage storage.
The method for co-processing domestic garbage in a cement kiln according to claim 1, wherein in the step b, the raw material for pyrolysis is a mixture of domestic garbage and fine slag; the domestic garbage has been dried in step a; The fine slag is a part of the product after pyrolysis in step b.
The method for co-processing domestic garbage in a cement kiln according to claim 1, wherein in the step c, the pyrolysis gas is used as a fuel, and the residue is classified and recycled after being cooled and screened.
The method for co-processing domestic garbage in a cement kiln according to claim 1, wherein the domestic garbage in the step a is subjected to a crushing process before drying.
A cement kiln co-processing domestic garbage system using the method for co-processing domestic garbage according to any one of claims 1 to 5, characterized in that it comprises drying equipment, garbage storage, pyrolysis furnace, residue cooling equipment and cement kiln a system; the drying device is in communication with a garbage reservoir; a gas inlet of the drying device is in communication with a gas outlet of a grate cooler of a cement kiln system; a gas outlet of the drying device and a gas inlet of the grate cooler Connected; the air inlet of the pyrolysis furnace is in communication with the garbage reservoir; the air inlet of the grate cooler is in communication with the garbage reservoir; the gas outlet of the pyrolysis furnace is in communication with the air inlet of the cement kiln decomposition furnace; The residue outlet of the pyrolysis furnace is connected to the residue cooling device.
The cement kiln co-processing domestic garbage system according to claim 6, wherein the pyrolysis furnace is further provided with a rotary screen, and the rotary screen inlet is connected with the pyrolysis drum outlet of the pyrolysis furnace; The rotary screen is provided with a first outlet communicating with the inlet of the pyrolysis cartridge and a second outlet communicating with the residue cooling device.
The cement kiln co-processing domestic garbage system according to claim 6, wherein the residue cooling device comprises a vibrating screen, a fine sand and a cooler; the fine sand is circulated in the vibrating screen and the cooler by the hoist flow.
The cement kiln co-processing domestic garbage system according to claim 6, wherein a crusher is further disposed between the garbage storage and the drying device.
The cement kiln co-processing domestic garbage system according to claim 6, wherein the garbage storage comprises a wet garbage storage connected to the drying equipment inlet and a dry garbage storage connected to the drying equipment outlet; the wet garbage The reservoir is in communication with the air inlet of the pyrolysis furnace and the air inlet of the grate cooler; the dry refuse reservoir is in communication with the feed port of the pyrolysis furnace.