CN118310315A - High-proportion substitute fuel pretreatment cement kiln incineration system and method - Google Patents

Abstract

The invention relates to the technical field of cement industry alternative fuels, and discloses a high-proportion alternative fuel pretreatment cement kiln incineration system which comprises a stack, a storage system, a rotary kiln, a pulverized coal burner, a cooler, a tertiary air pipe, a preheating raw material preheater, a crushing system, a homogenizing system, a metering system, a conveying system, a gravity type feeding system, a multifunctional decomposing furnace, an alternative fuel special burner and a wind power conveying system. According to the invention, the crushing granularity of the alternative fuel is controlled according to the suspension speed of the flue gas, so that the alternative fuel realizes suspension combustion in the multifunctional decomposing furnace, and is metered by the three metering systems, one path of the alternative fuel is fed into the special burner, the special burner and the pulverized coal burner are arranged up and down in the rotary kiln, and the pulverized coal combustion drives the alternative fuel to burn; the gravity type feeding system and the air locking blanking valve of the two switching switches are adopted to realize feeding of the alternative fuel, and air leakage in the feeding process is reduced.

Description

High-proportion substitute fuel pretreatment cement kiln incineration system and method

Technical Field

The invention relates to the technical field of cement industry alternative fuels, in particular to a high-proportion alternative fuel pretreatment cement kiln incineration system and method.

Background

With the consumption of fossil fuels, the stock of fossil fuels such as coal is gradually reduced, fossil energy such as coal is becoming more and more scarce, and the adoption of alternative fuels to replace traditional fossil fuels is a better choice for energy utilization, and the proportion of cement industry alternative fuels in developed countries such as europe is far higher than domestic, and along with the progress of technology and the cognition of energy sources, the cement industry adopts alternative fuels as heat sources of a novel dry cement burning system gradually rise, but because the heat value of the alternative fuels is often lower than that of fossil fuels, the water content is high, the alternative fuels are difficult to burn, and the substitution rate is lower.

The cement kiln system adopts partial alternative fuel, the flue gas amount of the system is increased, the wind speed of the decomposing furnace and the preheater system is increased, the residence time of flue gas and fuel in the decomposing furnace is shortened, the burnout rate of the alternative fuel is lowered, the alternative fuel is combusted and then is delayed, the alternative fuel enters the preheater system to continue to be combusted, the decomposing furnace and the preheater are caused to be in temperature reversal, local high temperature is caused for the preheater system, and the risk of skinning and blocking is caused.

In order to increase the use proportion of the alternative fuel, the cement industry currently commonly adopts a mode of externally adding a precombustion furnace, such as a step furnace, a rotary furnace, a fire grate furnace, a fluidized bed furnace, a hot tray furnace, a gasification furnace and the like, which are epitaxial technologies in the incineration field of household garbage, waste and the like, and the principle is that the externally adding combustion furnace or gasification furnace is adopted, the alternative fuel which is difficult to burn is burnt out of the decomposition furnace in advance or even burnt out, and then the unburned alternative fuel and generated flue gas are sent into the decomposition furnace so as to reduce the burning burden of the decomposition furnace. Because the heat value of the alternative fuel is higher than that of common household garbage and waste, the temperature generated by burning in the peripheral preheating furnace is higher, coking is easy to occur, raw materials are needed to be added for decomposition and heat absorption, and because the raw materials are finer powder, the precombustion furnace has poor adaptability to the powder, in particular to the grate furnace, the rotary furnace and the gasification furnace. The higher the heat value of the alternative fuel, the greater the risk of coking, the more raw materials need to be added, and the worse the combustion environment of the precombustor.

In addition, the calcined clinker in the rotary kiln needs higher flame temperature and flame intensity, the alternative fuel is often replaced by the kiln tail due to low heat value and difficult quick ignition and combustion, the kiln head is still made of fossil fuel, even if the heat value of the alternative fuel is higher, the common coal-fired, fuel-fired or natural gas burner is difficult to win, the alternative fuel special burner needs to be developed, and the alternative fuel special burner is difficult to realize 100% adoption of the alternative fuel in the kiln, so that the alternative fuel special burner often has the function of mixed combustion of the fossil fuel and the alternative fuel, and the adaptability of the special burner is difficult. The burner with central alternative fuel channels and peripheral pulverized coal channels in the alternative fuel special burner has the advantages that the alternative fuel and the coal are sprayed out from the same burner due to the difference between the combustion performance of the coal and the alternative fuel, and the alternative fuel has a great negative influence on pulverized coal combustion and influences the normal combustion of the pulverized coal. Thus, the use of kiln head replacement fuel remains a challenge, limiting the development of replacement fuels towards high replacement rates.

The heat value substitution rate of the substitute fuel of the novel domestic dry-method cement kiln system is lower, the average value is below 5%, the highest substitution rate is about 40%, and most of the substitute fuel is used at the tail of the kiln. In order to improve the heat value substitution rate of the alternative fuel and the adaptability of two large thermal equipment (a decomposing furnace and a rotary kiln) of the cement kiln system to the alternative fuel, key thermal equipment such as a decomposing furnace, a special burner for kiln heads and the like which are adaptive to the alternative fuel needs to be developed, and meanwhile, heat value control and granularity processing control are required to be carried out on the alternative fuel so as to improve the adaptability of the alternative fuel to a novel dry cement process.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a high-proportion alternative fuel pretreatment cement kiln incineration system and a high-proportion alternative fuel pretreatment cement kiln incineration method, wherein the kiln tail is developed and optimized through a multifunctional decomposing furnace structure, and the kiln head is developed through a special combustor for alternative fuel, so that the use proportion of the alternative fuel of the kiln head and the kiln tail is improved, the use proportion of the alternative fuel of the whole cement kiln system is further improved, the alternative fuel substitution rate is improved to more than 60%, and the consumption of fossil fuel in cement industry is reduced, so that the problems in the background technology are solved.

The invention provides the following technical scheme: the high-proportion substitute fuel pretreatment cement kiln incineration system comprises a stack shed, a storage system, a rotary kiln, a pulverized coal burner, a cooler, a tertiary air pipe, a pre-heated raw material preheater, a crushing system, a homogenization system, a metering system, a conveying system, a gravity type feeding system, a multifunctional decomposing furnace, a substitute fuel special burner and a wind power conveying system, wherein the crushing system crushes the granularity of the substitute fuel to the granularity of 6-10m/s, in which flue gas flow can suspend and rise, the crushed substitute fuel enters the homogenization system to be homogenized and mixed, and then is sent into the storage system, three metering systems are arranged at the discharge end of the storage system, namely a first metering system, a second metering system and a third metering system, and the gravity type feeding system comprises a first gravity type feeding system and a second gravity type feeding system; the first metering system is connected with the conveying system 1, the second metering system is connected with the conveying system 2, and the third metering system is connected with the conveying system 3; the conveying system 1 is connected with a wind power conveying system which is connected with a burner special for kiln head substitute fuel; the conveying system 2 is connected with the first gravity type feeding system, and the conveying system 3 is connected with the second gravity type feeding system; the tertiary air pipe is connected with the lower cone part of the multifunctional decomposing furnace, the first gravity type feeding system and the second gravity type feeding system are respectively connected with the multifunctional decomposing furnace, the connecting port is positioned 2-5 m above the interface of the tertiary air pipe and the multifunctional decomposing furnace, and the alternative fuel is supported and carried upwards by high-temperature mixed air flow formed by kiln tail flue gas and tertiary air and is combusted in the multifunctional decomposing furnace; the special burner for the kiln head substitute fuel is designed into an inner channel and an outer channel, wherein the inner channel is a substitute fuel channel, the substitute fuel is fed into the rotary kiln by air flow of the wind power conveying system, the outer channel is a rotational flow wind, and the rotational flow wind covers the substitute fuel, so that the substitute fuel forms a certain flame shape when being combusted in the rotary kiln; the special burner is arranged above the pulverized coal burner in the rotary kiln, and the pulverized coal burner drives the alternative fuel to burn through pulverized coal combustion.

Further, the first gravity feeding system consists of a first feeding slide, a first pneumatic blanking valve and a second pneumatic blanking valve, wherein the first pneumatic blanking valve and the second pneumatic blanking valve are vertically arranged up and down and are spaced by 3-6 m, the opening and closing time of the pneumatic blanking valve is less than or equal to 3s, and the first pneumatic blanking valve and the second pneumatic blanking valve are alternately switched on and off, and one is opened while the other is closed, so that the air locking effect during blanking is ensured; the second gravity type feeding system consists of a second feeding slide carriage, a third pneumatic blanking valve and a fourth pneumatic blanking valve, wherein the third pneumatic blanking valve and the fourth pneumatic blanking valve are vertically arranged up and down and are spaced by 3-6 m, the opening and closing time of the pneumatic blanking valves is less than or equal to 3s, and the third pneumatic blanking valve and the fourth pneumatic blanking valve are alternately switched on and off, and one way is opened while the other way is closed, so that the air locking effect during blanking is ensured.

On the basis of the scheme, a first spiral conveying reamer is arranged on the conveying system 2 and the first gravity feeding system, a second spiral conveying reamer is arranged on the conveying system 3 and the second gravity feeding system, and a sealing effect is added while forced feeding is achieved.

As a still further proposal of the invention, the first and the second alternative fuel feed inlets are positioned on the same horizontal plane of the multifunctional decomposing furnace and are uniformly distributed along the circumference of the multifunctional decomposing furnace.

Further, the penultimate cyclone of the pre-heated raw material preheater is connected with the multifunctional decomposing furnace, and the connected raw material feeding port I is positioned 1-4 m above the alternative fuel feeding port I and the alternative fuel feeding port II and is not on the same vertical line with the surfaces of the multifunctional decomposing furnace.

On the basis of the scheme, the blanking slide carriage of the penultimate cyclone of the pre-heating raw material preheater is divided into two paths, namely a first path of blanking slide carriage and a second path of blanking slide carriage, which are respectively connected with the multifunctional decomposing furnace to form a raw material feeding port I and a raw material feeding port II, wherein the raw material feeding port I is 1-4 m above the alternative fuel feeding port I and the alternative fuel feeding port II, the raw material feeding port II is 6-9 m above the alternative fuel feeding port I and the alternative fuel feeding port II, and the raw material feeding port I and the raw material feeding port II are not on the same vertical line on the surface of the multifunctional decomposing furnace.

As a still further scheme of the invention, a section of necking air pipe with the length more than or equal to 3m is arranged below the lower cone part of the multifunctional decomposing furnace, the air speed of the air flow of the clearance section of the air pipe is controlled to be more than or equal to 32m/s, and the raw materials and the alternative fuel are ensured not to fall into the rotary kiln.

Furthermore, the outer channel of the special burner is provided with a plurality of rectangular holes or round holes or square holes, each hole is uniformly distributed along the center of the special burner, and the holes spray out air flow through swirl angles to jointly form swirl wind.

A method for pretreating cement kiln incineration systems with a high proportion of alternative fuels, comprising the steps of:

S1: delivering the substituted fuel of the stack shed into a crushing system for crushing, wherein the granularity of the crushed substituted fuel meets the following requirements: the gas flow of the smoke of 6-10m/s in the multifunctional decomposing furnace can be suspended and lifted;

S2: delivering various crushed alternative fuels into a homogenizing system to homogenize and homogenize the alternative fuels, and delivering the homogenized alternative fuels into a storage system;

S3: the discharging end of the storage system is provided with three sets of metering systems, and the alternative fuel is fed into the rotary kiln for burning through the first metering system, the conveying system 1 and the wind power conveying system, and the alternative fuel is burnt to generate high-temperature flue gas for calcining cement clinker;

s4: the alternative fuel is fed into the multifunctional decomposing furnace through the second metering system, the conveying system 2 and the first gravity feeding system respectively, and is burnt in the multifunctional decomposing furnace under the tertiary air oxygen supply environment through the third metering system, the conveying system 3 and the second gravity feeding system, so that carbonate in the raw meal is decomposed, and the raw meal is carried to the preheated raw meal preheater along the air flow direction;

S5: the method realizes the crushing, homogenization, storage, metering and conveying of the alternative fuel, the rotary kiln and the multifunctional decomposing furnace which are fed into the cement kiln system realize the combustion of the alternative fuel through the multifunctional decomposing furnace and a burner special for the kiln head alternative fuel, the heat value ratio of the alternative fuel in the rotary kiln can reach over 50-100 percent, the heat value ratio of the alternative fuel in the multifunctional decomposing furnace can reach 80-100 percent, the heat value substitution rate of the alternative fuel in the whole cement kiln system can reach 60-100 percent, and the combustion of the high-ratio alternative fuel is realized.

The invention has the technical effects and advantages that:

1. According to the invention, the crushing granularity of the alternative fuel is controlled according to the suspension speed of the flue gas, so that the alternative fuel realizes suspension combustion in the multifunctional decomposing furnace and moves along the flow direction of the flue gas to the outlet of the decomposing furnace.

2. According to the invention, the three metering systems are used for metering, one path of the alternative fuel is fed into the special burner, the special burner and the pulverized coal burner are arranged up and down in the rotary kiln, and the pulverized coal combustion is used for driving the alternative fuel to burn; the two paths of symmetrical feeding multifunctional decomposing furnaces adopt a gravity feeding system and an air locking blanking valve of two switching switches to realize feeding of alternative fuels, and reduce air leakage in the feeding process.

3. The invention realizes forced feeding and adds a wind locking device by arranging the spiral conveying reamer, optimizes a feeding system and increases the wind locking effect

4. The special burner for the alternative fuel adopts an inner channel and an outer channel, and the alternative fuel is covered by the cyclone wind cage, so that the alternative fuel sprayed out of the inner channel forms a certain shape, the shape and the length of flame are controlled, and the calcination of clinker is facilitated.

5. According to the invention, the alternative fuel feeding port, the tertiary air inlet and the raw material feeding port are reasonably arranged on the multifunctional decomposing furnace, so that the alternative fuel and the raw material are better uniformly distributed and dispersed in the decomposing furnace, and are carried by the moving flue gas flow to be lifted and moved, so that the alternative fuel is better combusted and burned out, and the raw material is better decomposed.

6. In the invention, the alternative fuel and the raw meal are not arranged on a vertical line as far as possible in a staggered way, and the influence on the combustion of the alternative fuel in the gravity falling process of the raw meal is reduced as far as possible; the upper raw material feeding port and the lower raw material feeding port are staggered, so that materials are not mixed in the gravity falling process of the raw materials, the raw materials are supported by smoke and uniformly dispersed and carried upwards, and the method is beneficial to the temperature field control of the multifunctional decomposing furnace.

Drawings

FIG. 1 is a system process block diagram of the present invention.

FIG. 2 is a schematic diagram of the pulverized coal burner and alternative fuel dedicated burner arrangement of the present invention.

FIG. 3 is a schematic cross-sectional view of an alternative fuel-dedicated burner head of the present invention.

FIG. 4 is a schematic cross-sectional view of an alternative fuel-dedicated burner head of the present invention.

Fig. 5 is a process flow diagram of the present invention.

FIG. 6 is a schematic view of an alternative fuel inlet of the present invention.

Figure 7 is a schematic view of a raw material feed port according to the present invention.

Fig. 8 is a schematic horizontal cross-section of an alternative fuel inlet of the present invention.

The reference numerals are: 1. stacking sheds; 2. a pulverizing system; 3. a homogenization system; 4. a storage system; 5. a metering system; 5-1, a first metering system; 5-2, a second metering system; 5-3, a third metering system; 6. a conveying system; 6-1, a conveying system 1;6-2, a conveying system 2;6-3, conveying system 3; 7. a gravity feed system; 7-1, a first gravity feeding system; 7-1-1, a first feeding chute; 7-1-2, a first pneumatic blanking valve; 7-1-3, a second pneumatic blanking valve; 7-1-4, a first alternative fuel feed inlet; 7-2, a second gravity feeding system; 7-2-1, a second feeding chute; 7-2-2, a third pneumatic blanking valve; 7-2-3, a fourth pneumatic blanking valve; 7-2-4, a second alternative fuel feed inlet; 8. a rotary kiln; 9. a cooling machine; 10. a tertiary air duct; 11. a multifunctional decomposing furnace; 11-1, a lower cone; 11-2, a necking air pipe; 12. preheating a raw meal preheater; 12-1, a penultimate cyclone; 12-2-1, a raw material feeding port I; 12-2-2, a raw material feeding port II; 12-3, a first path of blanking chute; 12-4, a second path of blanking chute; 13. a pulverized coal burner; 14. a burner dedicated to alternative fuels; 15. a wind power delivery system; 16-1, a first spiral conveying reamer; 16-2, a second spiral conveying reamer.

Detailed Description

The embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which the embodiments of the present invention are shown by way of illustration only, and the invention is not limited to the embodiments of the present invention, but other embodiments of the present invention will be apparent to those skilled in the art without making any inventive effort.

Embodiments of the present invention will be described with reference to fig. 1-8.

Referring to fig. 1, which is a block diagram of a process flow chart of the present invention, a high-ratio alternative fuel pretreatment and cement kiln incineration system is disclosed, comprising a stack 1, a storage system 4, a rotary kiln 8, a cooler 9, a pulverized coal burner 13, a tertiary air pipe 10, and a preheated raw material preheater 12, and is characterized by further comprising: the method comprises the steps of a crushing system 2, a homogenizing system 3, a metering system 5, a conveying system 6, a gravity feeding system 7, a multifunctional decomposing furnace 11, a burner 14 special for alternative fuel and a wind power conveying system 15, wherein the crushing system 2 crushes the granularity of the alternative fuel to the granularity of 6-10m/s, which can be lifted by flue gas flow, the granularity of the alternative fuel is determined according to density and suspension speed, and crushing equipment of the crushing system is selected according to the granularity; the crushed alternative fuel is sent to a homogenizing system 3 for homogenizing and mixing so that the physical and chemical properties of the alternative fuel are uniform, and then sent to an alternative fuel storage system 4, wherein the storage system 4 can be a concrete factory, a steel plate bin, a concrete bin and the like and is provided with a rainproof facility for preventing fluctuation of water content of the stored alternative fuel; three sets of metering systems 5 are arranged at the discharge end of the storage system 4, namely a first metering system 5-1, a second metering system 5-2 and a third metering system 5-3; the following procedures of the three sets of metering systems are respectively provided with a conveying system 6, which are respectively and correspondingly marked as a conveying system 1, a conveying system 2 and a conveying system 3, and the corresponding numbers are respectively 6-1, 6-2 and 6-3; the gravity feed system 7 comprises a first gravity feed system 7-1 and a second gravity feed system 7-2. The first metering system 5-1 is connected with the conveying system 1 (6-1), the second metering system 5-2 is connected with the conveying system 2 (6-2), and the third metering system 5-3 is connected with the conveying system 3 (6-3); the conveying system 1 (6-1) is connected with the wind power conveying system 15, and the wind power conveying system 15 is connected with the kiln head substitute fuel special burner 14; the conveying system 2 (6-2) is connected with the first gravity feeding system 7-1, and the conveying system 3 (6-3) is connected with the second gravity feeding system 7-2; the tertiary air pipe 10 is connected with the lower cone 11-1 of the multifunctional decomposing furnace 11, the first gravity type feeding system 7-1 and the second gravity type feeding system 7-2 are respectively connected with the multifunctional decomposing furnace 11, the connecting port is positioned 2-5 m above the interface between the tertiary air pipe 10 and the multifunctional decomposing furnace 11, the alternative fuel is supported and carried upwards by the high-temperature mixed air flow formed by kiln tail flue gas and tertiary air, and is combusted in the multifunctional decomposing furnace 11, and the combustion heat is used for decomposing raw materials.

In the invention, in addition to the incineration of the alternative fuel by the multifunctional decomposing furnace 11, the alternative fuel is combusted in the rotary kiln, as shown in figures 2,3 and 4, the kiln head alternative fuel is combusted by adopting the special combustor 14, the special combustor 14 and the pulverized coal combustor are simultaneously arranged in the rotary kiln, the special combustor 14 consists of an inner channel 14-1 and an outer channel 14-2, the inner channel 14-1 is an alternative fuel channel, the alternative fuel is fed into the rotary kiln 8 by the air flow of the wind power conveying system 15, the outer channel 14-2 is a rotational flow air channel, as shown in figures 3 and 4, the rotational flow air covers the alternative fuel, so that the alternative fuel forms a certain current situation and flame shape when being sprayed and combusted in the rotary kiln 8, and the rotational flow air can be set into a plurality of round holes; as shown in fig. 2, the special burner 14 is arranged above the pulverized coal burner 13 in the rotary kiln 8, the pulverized coal burner 13 burns by high-temperature combustion of pulverized coal to drive the alternative fuel to burn, and after the pulverized coal burns, a certain high-temperature flue gas is formed, which provides favorable conditions for drying, volatile separation, precombustion and combustion of the alternative fuel, and the alternative fuel and the pulverized coal are formed in the rotary kiln to burn in a mixed mode, and the pulverized coal burner 13 can also be designed as a burner with a natural gas or fuel pipeline and a jet orifice so as to realize that the natural gas or fuel replaces the pulverized coal, and the special burner 14 is driven to burn the alternative fuel through combustion.

In order to improve the feeding sealing effect, as shown in fig. 6, the first gravity feeding system 7-1 consists of a first feeding slide carriage 7-1-1, a first pneumatic blanking valve 7-1-2 and a second pneumatic blanking valve 7-1-3, wherein the two pneumatic blanking valves 7-1-2 and 7-1-3 are vertically arranged up and down along the first feeding slide carriage 7-1 and are separated by 3-6 m in height, the opening and closing time of the pneumatic blanking valves is less than or equal to 3s, when the alternative fuel is fed into the multifunctional decomposing furnace 11 through the first gravity feeding system 7-1, the two pneumatic blanking valves 7-1-2 and 7-1-3 are alternately switched, one is opened, and the other is closed, so that the air locking effect during blanking is ensured; the second gravity type feeding system 7-2 consists of a second feeding slide carriage 7-2-1, a third pneumatic blanking valve 7-2-2 and a fourth pneumatic blanking valve 7-2-3, wherein the second feeding slide carriage 7-1-1 is vertically arranged up and down and is spaced by 3-6 m in height, the opening and closing time of the pneumatic blanking valves is less than or equal to 3s, when alternative fuel is fed into the multifunctional decomposing furnace 11 through the second gravity type feeding system 7-2, the two pneumatic blanking valves 7-2-2 and 7-2-3 are alternately switched on and off, and one is opened while the other is closed, so that the air locking effect during blanking is ensured. In order to ensure that the two sets of gravity feeding systems 7-1 and 7-2 are symmetrically fed, the two sets of gravity feeding systems 7-1 and 7-2 are consistent in shape selection and are symmetrically arranged according to the central line of the multifunctional decomposing furnace 11.

In order to improve the air locking effect of the invention when replacing fuel feeding, as shown in fig. 5, a first spiral conveying reamer 16-1 is arranged between the conveying system 2 (6-2) and the first gravity feeding system 7-1, and a second spiral conveying reamer 16-2 is arranged between the conveying system 3 (6-3) and the second gravity feeding system 7-2, so that forced feeding is realized, and a sealing effect is also added.

In order to optimize the effects of uniform feeding and homogeneous combustion of the alternative fuel of the multifunctional decomposing furnace 11, as shown in fig. 6 and 8, the first 7-1-4 and the second 7-2-4 feed ports of the alternative fuel are positioned on the same horizontal plane of the multifunctional decomposing furnace 11 and are uniformly distributed along the circumference of the multifunctional decomposing furnace 11, compared with the arrangement that one feed port or two feed ports are positioned close to each other, the alternative fuel is more dispersed and more easily uniformly distributed in the multifunctional decomposing furnace 11, and the temperature field inside the multifunctional decomposing furnace 11 after the alternative fuel is combusted is more uniform, thereby being beneficial to controlling the internal temperature of the multifunctional decomposing furnace 11.

In order to improve the dispersion effect of the raw materials in the multifunctional decomposing furnace 11, as shown in fig. 7, the blanking chute of the penultimate cyclone 12-1 of the preheated raw material preheater 12 is divided into two paths, namely a first path of blanking chute 12-3 and a second path of blanking chute 12-4, the two paths of blanking chute 12-3 and 12-4 are respectively connected with the multifunctional decomposing furnace 11 to form a raw material feeding port I12-2-1, a raw material feeding port II 12-2-2, the raw material feeding port I12-2-1 is 1-4 m above the level of the alternative fuel feeding ports 7-1-4 and 7-2-4, the raw material feeding port II 12-2-2 is 6-9 m above the level of the alternative fuel feeding ports I7-1-4 and 7-2-4, and the raw material feeding ports I12-2-1 and II 12-2-2 are not arranged on the same vertical line on the surface of the multifunctional decomposing furnace 11, so that the staggered arrangement of the two raw material feeding ports is realized. The raw material feeding ports 12-2-1 and 12-2-2 are designed above the alternative fuel feeding port, so that the alternative fuel is firstly contacted with tertiary air for combustion, and then the temperature after combustion is reduced through raw material decomposition heat absorption, so that the temperature of flue gas in the decomposing furnace is not too high, and the raw material is generally prevented from forming liquid phase under the environment of high temperature (more than or equal to 1050 ℃) at 850-1000 ℃, and the skinning and sticky material on the inner surface of the multifunctional decomposing furnace 11 are caused; if the raw materials are fed into the multifunctional decomposing furnace 11, if the raw materials are fed into the multifunctional decomposing furnace 11 before the raw materials are fed into the furnace and after the alternative fuel and the fuel are combusted, the raw materials absorb heat and the temperature is reduced below the raw material decomposition temperature, so that the fuel combustion pursues the raw material decomposition in the whole multifunctional decomposing furnace 11, most of the temperature in the whole decomposing furnace cannot reach the raw material decomposition temperature, and even if the temperature is increased to be above the decomposition temperature through the burnout of the fuel when the raw materials are discharged from the decomposing furnace, the decomposition rate of the raw materials in the multifunctional decomposing furnace 11 is reduced, and the calcination of clinker in the rotary kiln 8 is affected.

In order to ensure that the alternative fuel can be well supported by the flue gas in the decomposing furnace, as shown in fig. 6 and 7, a section of shrinkage air pipe 11-2 with the length more than or equal to 3m is arranged below the lower cone part 11-1 of the multifunctional decomposing furnace 11, the air flow speed of the clean cross section of the shrinkage air pipe 11-2 is controlled to be more than or equal to 32m/s, the raw meal and the alternative fuel are ensured not to fall into the rotary kiln 8, particularly the alternative fuel with larger block size and density, the shrinkage air speed between the multifunctional decomposing furnace 11 and the rotary kiln 8 is more improved, even controlled to be 35-50 m/s, and the air speed far exceeds that of the coal dust of the normal decomposing furnace as fuel, so that the block-shaped alternative fuel is supported by the flue gas in the rotary kiln, the block-shaped alternative fuel is burnt in the multifunctional decomposing furnace 11 and moves along with the flue gas flow, and the alternative fuel is blocked at the shrinkage part by the flue gas.

In order to improve the implementation effect of the swirl wind of the outer channel 14-2 of the special burner 14, for example, in fig. 3 and 4, the outer channel is designed to be formed by a plurality of rectangular holes or round holes or square holes, each hole is uniformly distributed along the center of the special burner 14, each hole forms swirl wind together by jetting air flow through swirl angles, the substitute fuel jetted from the central pipeline is wrapped by swirl to form a certain current situation, a certain flame current situation and flame length are formed when the substitute fuel is combusted in the rotary kiln, and a favorable support is provided for clinker calcination.

The invention relates to a high-proportion alternative fuel pretreatment and cement kiln incineration method, which is characterized by comprising the following steps:

Firstly, delivering the substitute fuel of the stack shed 1 into a crushing system 2 for crushing, wherein the granularity of the crushed substitute fuel meets the following requirements: the smoke gas flow of 6-10m/s in the multifunctional decomposing furnace 11 can suspend and rise, so that various alternative fuels can suspend and rise in the multifunctional decomposing furnace 11 without sinking and gathering.

In the second step, the crushed alternative fuel is sent to a homogenization system 3 to homogenize and homogenize the alternative fuel, and then sent to a storage system 4.

Third, the discharging end of the storage system 4 is provided with three sets of metering systems 5, and the alternative fuel is fed into the rotary kiln 8 to be burnt through the first metering system 5-1, the conveying system 16-1, the wind power conveying system 15 and the special burner 14 in sequence, and the alternative fuel is burnt under the driving of the coal injection of the coal powder burner 13 to produce high-temperature flue gas to supply cement clinker for calcination.

Fourth, the alternative fuel is fed into the multifunctional decomposing furnace 11 through the second metering system 5-2, the conveying system 2 (6-2) and the first gravity feeding system 7-1, and is fed into the multifunctional decomposing furnace 11 through the third metering system 5-3, the conveying system 3 (6-3) and the second gravity feeding system 7-2, and is burnt in the triple air oxygen supply environment in the multifunctional decomposing furnace 11, so that high-temperature flue gas is generated for decomposing carbonate in raw materials, and the flue gas carries the raw materials to enter the preheating raw material preheater 12 along the air flow direction.

The method comprises the steps of crushing, homogenizing, storing, metering and conveying the alternative fuel, uniformly and quantitatively spraying the alternative fuel into the rotary kiln 8 of the cement kiln system and feeding the alternative fuel into the multifunctional decomposing furnace 11, and realizing the combustion of the alternative fuel through the multifunctional decomposing furnace 11 and the special burner 14 for kiln head alternative fuel, wherein the heat value ratio of the alternative fuel in the rotary kiln 8 can reach more than 50-100%, coal dust is fully adopted as the fuel in the rotary kiln 8 at the beginning of feeding, after the clinker is stably discharged from the kiln and the high-temperature field in the kiln is stable, the coal is gradually reduced, the special burner 14 is gradually sprayed with the alternative fuel, the heat value ratio of the alternative fuel in the multifunctional decomposing furnace 11 can be gradually increased, the heat value ratio of the alternative fuel in the whole cement kiln system can reach 60-100%, the combustion of the alternative fuel in high ratio is realized, the gas-solid two-phase flow field in the whole multifunctional decomposing furnace 11 is reasonable, and the thermal system and the novel dry method technology have high consistency.

In this description, it should be noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (9)

1. The utility model provides a high proportion alternative fuel preliminary treatment cement kiln burns system, contains heap canopy (1), storage system (4), rotary kiln (8), buggy combustor (13), cooler (9), tertiary air pipe (10), preheats raw materials preheater (12), its characterized in that: the device also comprises a crushing system (2), a homogenizing system (3), a metering system (5), a conveying system (6), a gravity type feeding system (7), a multifunctional decomposing furnace (11), a special burner (14) for alternative fuel and a wind power conveying system (15), wherein the crushing system (2) crushes the granularity of the alternative fuel to the granularity which can be suspended and raised by the flue gas flow of 6-10m/s, the crushed alternative fuel enters the homogenizing system (3) for homogenizing and mixing, and is sent to a storage system (4), three sets of metering systems (5) are arranged at the discharge end of the storage system (4), namely a first metering system (5-1), a second metering system (5-2) and a third metering system (5-3), and the gravity type feeding system (7) comprises the first gravity type feeding system (7-1) and the second gravity type feeding system (7-2); the first metering system (5-1) is connected with the conveying system 1 (6-1), the second metering system (5-2) is connected with the conveying system 2 (6-2), and the third metering system (5-3) is connected with the conveying system 3 (6-3); the conveying system 1 (6-1) is connected with the wind power conveying system (15), and the wind power conveying system (15) is connected with a burner (14) special for kiln head substitute fuel; the conveying system 2 (6-2) is connected with the first gravity type feeding system (7-1), and the conveying system 3 (6-3) is connected with the second gravity type feeding system (7-2); the tertiary air pipe (10) is connected with the lower cone part (11-1) of the multifunctional decomposing furnace (11), the first gravity type feeding system (7-1) and the second gravity type feeding system (7-2) are respectively connected with the multifunctional decomposing furnace (11), the connecting port is positioned 2-5 m above the interface between the tertiary air pipe (10) and the multifunctional decomposing furnace (11), and the alternative fuel is supported and carried upwards by high-temperature mixed air flow formed by kiln tail flue gas and tertiary air and is combusted in the multifunctional decomposing furnace (11); the special burner (14) for kiln head substitute fuel is designed into an inner channel (14-1) and an outer channel (14-2), the inner channel (14-1) is a substitute fuel channel, the substitute fuel is fed into the rotary kiln (8) by air flow of the wind power conveying system (15), the outer channel (14-2) is a rotational flow wind, and the rotational flow wind covers the substitute fuel, so that the substitute fuel forms a certain flame shape when being combusted in the rotary kiln (8); the special burner (14) is arranged above the pulverized coal burner (13) in the rotary kiln (8), and the pulverized coal burner (13) drives the alternative fuel to burn through pulverized coal combustion.

2. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 1, characterised in that: the first gravity type feeding system (7-1) consists of a first feeding slide (7-1-1), a first pneumatic blanking valve (7-1-2) and a second pneumatic blanking valve (7-1-3), wherein the first pneumatic blanking valve (7-1-2) and the second pneumatic blanking valve (7-1-3) are vertically arranged up and down and are spaced by 3-6 m, the opening and closing time of the pneumatic blanking valves is less than or equal to 3s, the first pneumatic blanking valve (7-1-2) and the second pneumatic blanking valve (7-1-3) are alternately switched, one channel is opened, and the other channel is closed at the same time, so that the air locking effect during blanking is ensured; the second gravity type feeding system (7-2) consists of a second feeding slide (7-2-1), a third pneumatic blanking valve (7-2-2) and a fourth pneumatic blanking valve (7-2-3), wherein the third pneumatic blanking valve (7-2-2) and the fourth pneumatic blanking valve (7-2-3) are vertically arranged up and down and are spaced by 3-6 m, the opening and closing time of the pneumatic blanking valves is less than or equal to 3s, the third pneumatic blanking valve (7-2-2) and the fourth pneumatic blanking valve (7-2-3) are alternately switched, one is opened, and the other is closed at the same time, so that the air locking effect during blanking is ensured.

3. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 1 or 2, characterised in that: the conveying system 2 (6-2) and the first gravity type feeding system (7-1) are provided with a first spiral conveying reamer (16-1), the conveying system 3 (6-3) and the second gravity type feeding system (7-2) are provided with a second spiral conveying reamer (16-2), and a sealing effect is added while forced feeding is realized.

4. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 1 or 2, characterised in that: the first alternative fuel feed inlet (7-1-4) and the second alternative fuel feed inlet (7-2-4) are positioned on the same horizontal plane of the multifunctional decomposing furnace (11) and are uniformly distributed along the circumference of the multifunctional decomposing furnace (11).

5. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 1 or 2, characterised in that: the penultimate cyclone (12-1) of the preheating raw material preheater (12) is connected with the multifunctional decomposing furnace (11), the connected raw material feeding port I (12-2-1) is positioned above the alternative fuel feeding port I (7-1-4) and the alternative fuel feeding port II (7-2-4) by 1-4 m, and the raw material feeding port I (7-1-4) and the raw material feeding port II (7-2-4) are not on the same vertical line on the surface of the multifunctional decomposing furnace (11).

6. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 1 or 2, characterised in that: the feeding chute of the penultimate cyclone (12-1) of the preheating raw material preheater (12) is divided into two paths, namely a first path of feeding chute (12-3) and a second path of feeding chute (12-4), which are respectively connected with the multifunctional decomposing furnace (11) to form a raw material feeding port I (12-2-1) and a raw material feeding port II (12-2-2), wherein the raw material feeding port I (12-2-1) is 1-4 m above the alternative fuel feeding port I (7-1-4) and the alternative fuel feeding port II (7-2-4), the raw material feeding port II (12-2-2) is 6-9 m above the alternative fuel feeding port I (7-1-4) and the alternative fuel feeding port II (7-2-4), and the raw material feeding port I (12-2-1) and the raw material feeding port II (12-2-2) are not on the same vertical line on the surface of the multifunctional decomposing furnace (11).

7. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 6, characterised in that: a section of necking air pipe (11-2) with the length more than or equal to 3m is arranged below the lower cone part (11-1) of the multifunctional decomposing furnace (11), the air speed of air flow of the air pipe clearance section is controlled to be more than or equal to 32m/s, and the raw materials and the alternative fuel are ensured not to fall into the rotary kiln (8).

8. A high ratio alternative fuel pretreatment cement kiln incineration system according to claim 1, characterised in that: the outer channel (14-2) of the special burner (14) is provided with a plurality of rectangular holes or round holes or square holes, the holes are uniformly distributed along the center of the special burner (14), and the holes spray out air flow through swirl angles to jointly form swirl wind.

9. A method of pretreating a cement kiln incineration system based on a high proportion of alternative fuel according to any one of claims 1 to 8, characterised in that: comprises the following steps:

s1: delivering the substitute fuel of the stack shed (1) into a crushing system (2) for crushing, wherein the granularity of the crushed substitute fuel meets the following requirements: the smoke gas flow of 6-10m/s in the multifunctional decomposing furnace (11) can be suspended and lifted;

S2: feeding various crushed alternative fuels into a homogenizing system (3) to homogenize and homogenize the alternative fuels, and then feeding the homogenized alternative fuels into a storage system (4);

S3: three sets of metering systems (5) are arranged at the discharge end of the storage system (4), and the alternative fuel is fed into the rotary kiln (8) through the first metering system (5-1), the conveying system (6-1) and the wind power conveying system (15) for burning, so that the alternative fuel is burnt to generate high-temperature flue gas to supply cement clinker for calcination;

S4: the alternative fuel is respectively delivered into a multifunctional decomposing furnace (11) through a second metering system (5-2), a conveying system 2 (6-2) and a first gravity type feeding system (7-1), and delivered into the multifunctional decomposing furnace (11) through a third metering system (5-3), a conveying system 3 (6-3) and a second gravity type feeding system (7-2), is burnt in the multifunctional decomposing furnace (11) in a tertiary air oxygen supply environment, is used for decomposing carbonate in raw materials, and is carried to a preheated raw material preheater (12) along the air flow direction;

S5: the rotary kiln (8) and the multifunctional decomposing furnace (11) which are fed into the cement kiln system can realize the combustion of the alternative fuel through the multifunctional decomposing furnace (11) and the special burner (14) for kiln head alternative fuel, the heat value ratio of the alternative fuel in the rotary kiln (8) can reach more than 50-100%, the heat value ratio of the alternative fuel in the multifunctional decomposing furnace (11) can reach 80-100%, the heat value substitution rate of the alternative fuel in the whole cement kiln system can reach 60-100%, and the combustion of the high-ratio alternative fuel is realized.