Method and system for treating suspended calcined clay

Abstract

The present invention provides a method and system for treating suspended calcined clay, wherein the treatment system includes: a decomposition furnace, the decomposition furnace is connected to a burner; a membrane separation oxygen production device, the separated pure oxygen and residual gas are transported to an oxygen storage tank and a by-product storage tank respectively; a preheating device, used for heat exchange between clay and flue gas generated by calcining clay in the decomposition furnace; a cooling device, used for heat exchange between clinker and residual gas transported from a by-product pipeline; one end of the first branch is connected to the by-product pipeline, and the other end is connected to the oxygen pipeline, the first branch is provided with a first valve, and a second valve is provided on the front section of the oxygen pipeline; the first valve and the second valve re-adjust the mixed amount of pure oxygen and residual gas to make the decomposition furnace calcine in a reducing atmosphere. According to the treatment system provided by the present invention, air is directly used to simultaneously complete the calcination of clinker and the cooling of clinker while keeping the color gray.

Description

Technical Field

[0001] The invention relates to the technical field of cement calcination, and in particular to a method and system for treating suspended calcined clay. Background Art

[0002] Cement manufacturing is at the core of global infrastructure development, just like every energy-intensive industry. The production process of silicate cement is representative in cement production. It uses limestone and clay as the main raw materials, which are crushed, batched, and ground into raw materials, which are then fed into cement kilns to be calcined into clinker. The clinker is then ground with an appropriate amount of gypsum (sometimes mixed materials or admixtures). Cement production can generally be divided into three processes: raw material preparation, clinker calcination, and cement production. Cement production can be divided into two types: dry process (including semi-dry process) and wet process (including semi-wet process) depending on the raw material preparation method.

[0003] Among them, if the clay is in a reducing atmosphere during calcination, the finished product is gray. After it is added to clinker and ground into cement, it does not affect the color of the cement. If the clay is in an oxidizing atmosphere during calcination, the finished product is generally reddish brown. After it is added to clinker and ground into cement, it will affect the color of the cement.

[0004] In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art:

[0005] When producing cement by dry process, the raw materials are generally dried and ground at the same time, or dried first and ground into raw material powder before feeding into dry kiln to calcine into clinker. Among them, the raw materials (clay) are calcined in the dry kiln by adding fuel and introducing air combustion to provide heat. Air is the most easily available gas in nature. It cannot guarantee a reducing atmosphere when it is directly mixed with fuel and burned. Therefore, in order to achieve a reducing atmosphere when clay is calcined, it is usually necessary to inject additional reducing gas, which undoubtedly requires the addition of other equipment, resulting in a more complex structure and increased costs. In addition, the clinker generated by calcining the raw materials (clay) needs to be cooled so that it can be made into cement later. If the clinker is exposed to oxygen when it is cooled, the clinker will be recolored, affecting the final color of the cement.

[0006] Therefore, a method and system for treating suspended calcined clay are needed to at least partially solve the above technical problems. Summary of the invention

[0007] The embodiment of the present invention provides a method and system for treating suspended calcined clay, which has a simple structure and directly utilizes the most easily available air in nature, and keeps the color of the clinker gray when calcining the clinker and cooling the clinker at the same time.

[0008] In a first aspect, the present invention provides a system for treating suspended calcined clay, comprising:

[0009] a calciner for calcining clay, the calciner being connected to a burner provided with a gas inlet and a fuel inlet;

[0010] A membrane separation oxygen production device is used to separate air into pure oxygen and residual gas, and the separated pure oxygen and residual gas are respectively transported to an oxygen storage tank and a by-product storage tank; wherein the oxygen storage tank is connected to the gas inlet via an oxygen pipeline, and the by-product storage tank is connected to the by-product pipeline;

[0011] a preheating device connected to the decomposition furnace, used for heat exchange between clay and flue gas generated by calcining clay in the decomposition furnace, the preheating device comprising a clay inlet for introducing clay, a clay outlet for leading the clay after heat exchange to the decomposition furnace, and a first clinker outlet for leading clinker generated by calcining clay in the decomposition furnace;

[0012] A cooling device connected to the by-product pipeline and the first clinker outlet, respectively, for heat exchange between the clinker and the residual gas transported by the by-product pipeline, the cooling device comprising a gas outlet for leading the residual gas after heat exchange to the decomposition furnace and a second clinker outlet for leading the clinker after heat exchange;

[0013] a first branch, one end of the first branch being connected to the byproduct pipeline, the other end of the first branch being connected to the oxygen pipeline, the first branch being provided with a first valve, and the oxygen pipeline being provided with a second valve on a front section of the pipeline at a connection with the first branch;

[0014] The first valve and the second valve remix pure oxygen and residual gas through their respective openings to make the decomposition furnace calcine in a reducing atmosphere, wherein the pure oxygen accounts for 17%-18% of the remixed pure oxygen and residual gas.

[0015] According to the treatment system of the present invention, the air is separated into pure oxygen and residual gas by using a membrane separation oxygen production device, and a part of the residual gas is re-mixed with pure oxygen and transported to the burner for combustion, so that the decomposition furnace is in a reducing atmosphere for calcination; another part of the residual gas is transported into the cooling device as cooling air to exchange heat with the clinker generated by calcining clay in the decomposition furnace, so as to ensure that the clinker is cooled in an oxygen-free environment and prevent the clinker from being recolored due to the presence of oxygen; and the residual gas after heat exchange with the clinker in the cooling device finally enters the decomposition furnace, further ensuring that the decomposition furnace is in a reducing atmosphere; at the same time, before the clay enters the decomposition furnace, it exchanges heat with the flue gas generated by calcining clay in the decomposition furnace in the preheating device. The entire treatment system directly uses the most easily available air in nature, and can keep the clinker gray in color when calcining and cooling the clinker at the same time, with a simple structure and low energy consumption.

[0016] Optionally, the preheating device comprises a plurality of cyclones arranged from top to bottom, the bottom material outlet of the lowest cyclone is connected to the cooling device, the gas inlet of the lowest cyclone is connected to the decomposition furnace, the top gas outlet of the highest cyclone is connected to the exhaust gas pipe, and the bottom material outlet of the upper cyclone adjacent to the lowest cyclone is connected to the decomposition furnace; wherein the gas outlet of the lower cyclone is connected to the upper cyclone through a connecting pipe, and the bottom material outlet of the upper cyclone is connected to the lower connecting pipe;

[0017] The raw material is fed into the connecting pipe located at the top.

[0018] Optionally, the cooling device also includes a plurality of cyclones arranged from top to bottom, the bottom material outlet of the cyclone located at the bottom is connected to a zipper machine or other equipment, the gas inlet of the cyclone located at the bottom is connected to the by-product pipeline, and the top gas outlet of the cyclone located at the top is connected to the decomposition furnace; wherein the gas outlet of the cyclone located at the bottom is connected to the cyclone located at the top through a connecting pipeline, and the bottom material outlet of the cyclone located at the top is connected to the connecting pipeline at the bottom;

[0019] The clinker discharged from the preheating device is put into the connecting pipe located at the top.

[0020] Optionally, the exhaust gas pipeline is further provided with a second branch on the rear section of the pipeline connected to the connection between the oxygen pipeline and the first branch, and the second branch is provided with a corresponding valve.

[0021] Optionally, the exhaust gas pipeline is further provided with a third branch connected to the by-product pipeline, and the third branch is provided with a corresponding valve.

[0022] Optionally, the treatment system further comprises: a fourth branch arranged on the rear section of the pipeline at the connection between the oxygen pipeline and the first branch, the fourth branch being provided with a corresponding valve for introducing air.

[0023] Optionally, the calciner is further provided with an alternative fuel inlet.

[0024] In a second aspect, the present invention further provides a method for treating suspended calcined clay, and a treatment system based on the above technical solution specifically comprises the following steps:

[0025] The membrane separation oxygen production device separates air into pure oxygen and residual gas, and the separated pure oxygen and residual gas are transported to the oxygen storage tank and the by-product storage tank respectively;

[0026] A portion of the remaining gas in the by-product storage tank is re-adjusted with the pure oxygen in the oxygen storage tank through the opening of the first valve and the second valve and transported to the burner to be mixed with the fuel and burned, so that the decomposition furnace is in a reducing atmosphere for calcination;

[0027] The remaining gas in the by-product storage tank is transported to the cooling device as cooling air to exchange heat with the clinker generated by calcining clay in the decomposition furnace, so as to ensure that the clinker is cooled in an oxygen-free environment and prevent the clinker from being recolored due to the presence of oxygen; and the remaining gas in the cooling device after heat exchange with the clinker finally enters the decomposition furnace, further ensuring that the decomposition furnace is in a reducing atmosphere;

[0028] Before the clay enters the decomposition furnace for calcination, it is preheated by heat exchange with the flue gas generated by the decomposition furnace for calcination of the clay.

[0029] By utilizing the technical solution according to the embodiment of the present invention, the beneficial effects that can be obtained are at least:

[0030] 1. Use membrane separation oxygen production device to separate air into pure oxygen and residual gas. Part of the residual gas is mixed with pure oxygen and transported to the burner for combustion, so that the decomposition furnace is in a reducing atmosphere for calcination; another part of the residual gas is transported into the cooling device as cooling air to exchange heat with the clinker generated by calcining clay in the decomposition furnace, so as to ensure that the clinker is cooled in an oxygen-free environment and prevent the clinker from being recolored due to the presence of oxygen; and the residual gas after heat exchange with the clinker in the cooling device finally enters the decomposition furnace, further ensuring that the decomposition furnace is in a reducing atmosphere; the entire processing system directly uses the most easily available air in nature, and can simultaneously complete the calcination of clinker and the cooling of clinker while keeping the clinker color gray;

[0031] 2. Before the clay enters the decomposition furnace, it exchanges heat with the flue gas generated by calcining the clay in the decomposition furnace in the preheating device. The entire treatment system has a simple structure and low energy consumption.

[0032] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically indicated in the specification and the accompanying drawings.

[0033] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are only for illustrating the principles of the present invention. In order to facilitate the illustration and description of some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other components in the exemplary device actually manufactured according to the present invention. In the drawings:

[0035] Figure 1 FIG. 1 is an overall schematic diagram of a system for processing suspended calcined clay according to an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] 100. Processing system; 110. Decomposition furnace; 111. Burner; 120. Membrane separation oxygen production device; 121. Oxygen storage tank; 122. By-product storage tank; 123. Oxygen pipeline; 124. By-product pipeline; 130. Preheating device; 140. Cooling device; 150. First branch; 151. First valve; 152. Second valve; 160. Waste gas pipeline; 170. Cyclone; 171. Connecting pipeline; 182. Second branch; 183. Third branch; 184. Fourth branch; 191. Chimney; 192. Zipper machine. DETAILED DESCRIPTION

[0038] By referring to the exemplary embodiments, the objects and functions of the present invention and the methods for achieving these objects and functions will be explained. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in different forms. The essence of the description is only to help those skilled in the relevant art to comprehensively understand the specific details of the present invention.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0040] Ordinal numbers such as "first" and "second" cited in the present invention are merely identifications and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of the "second component", and the term "second component" itself does not imply the existence of the "first component".

[0041] It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and similar expressions used in this document are for illustrative purposes only and are not limiting.

[0042] In a first aspect, the present invention provides a suspended calcined clay processing system 100, which is applied to the field of cement calcination technology to solve the problem of complex equipment structure and high cost caused by the existing cement calcination equipment in order to ensure that the color of calcined clay raw materials and cooled clinker is gray.

[0043] like Figure 1 As shown, in a preferred embodiment, the processing system 100 includes a decomposition furnace 110, a membrane separation oxygen production device 120, a preheating device 130, a cooling device 140 and a first branch 150. The decomposition furnace 110 is used as a device for calcining clay. The membrane separation oxygen production device 120 is used to separate air into pure oxygen and residual gas. The preheating device 130 is used to preheat clay. The cooling device 140 is used to cool the clinker generated by calcination. The first branch 150 is used to remix the residual gas with pure oxygen to change the proportion of pure oxygen (oxygen).

[0044] Specifically, the calciner 110 is used to calcine clay, so that the clay is calcined into mature material in the heat provided by the combustion of fuel. The calciner 110 is a common calcining device in the art, and the specific structure is not described here. The calciner 110 is connected to a burner 111 provided with a gas inlet and a fuel inlet. In order to ensure the normal operation of the calciner 110, the calciner 110 can also be provided with an alternative fuel inlet (AFR inlet), which can partially or completely replace the fuel fed into the fuel inlet of the burner 111.

[0045] The membrane separation oxygen production device 120 is a prior art product for oxygen production. In this embodiment, it is used to separate air into pure oxygen and residual gas. Among them, the residual gas is the gas component in the air other than oxygen. In addition, pure oxygen can refer to pure oxygen, or it can be said that it is oxygen with an oxygen concentration of >99%. The separated pure oxygen and residual gas are respectively transported to the oxygen storage tank 121 and the by-product storage tank 122, and are stored for use. Among them, the oxygen storage tank 121 is connected to the gas inlet of the burner 111 via the oxygen pipeline 123. The by-product storage tank 122 is connected to the by-product pipeline 124, and part of the residual gas is transported to the cooling device 140 (mentioned below) through the by-product pipeline 124. In addition, when the oxygen storage tank 121 is saturated, the membrane separation oxygen production device 120 can be turned off to reduce the overall operating energy consumption of the system, and restarted when the oxygen is reduced to the critical value of the storage tank.

[0046] The preheating device 130 is connected to the decomposition furnace 110, and is used for heat exchange between clay and flue gas generated by calcining clay in the decomposition furnace 110. The preheating device 130 includes a clay inlet for introducing clay, a clay outlet for leading the clay after heat exchange to the decomposition furnace 110, and a first clinker outlet for leading the clinker generated by calcining clay in the decomposition furnace 110. The clinker generated by calcining clay in the decomposition furnace 110 is led to the cooling device 140 through the first clinker outlet. The preheating device 130 can adopt an existing technical device.

[0047] The cooling device 140 is connected to the by-product pipeline 124 and the first clinker outlet, respectively, and is used for heat exchange between the clinker and the residual gas transported by the by-product pipeline 124. The cooling device 140 includes a gas outlet for leading the residual gas after heat exchange to the decomposition furnace 110 and a second clinker outlet for leading the clinker after heat exchange. Of course, the cooling device 140 also includes a port for receiving the residual gas transported by the by-product pipeline 124 and a port for receiving the clinker. Among them, the cooling device 140 can also adopt a prior art device. When the clinker is cooled, if there is oxygen, a phase transition process from magnetite to hematite will occur, and the color of the clinker will change from gray to other colors. The residual gas transported by the by-product pipeline 124 cools the clinker. Since the oxygen is stripped from the by-product (residual gas) of the membrane separation oxygen production device 120, when it acts as cooling wind, the finished product can be cooled to below 120°C, and there is no color change during the process, that is, the color of the finished product is gray.

[0048] One end of the first branch 150 is connected to the byproduct pipeline 124 for introducing part of the residual gas. The other end of the first branch 150 is connected to the oxygen pipeline 123 for mixing the introduced residual gas with pure oxygen. The first branch 150 is provided with a first valve 151 for adjusting the flow of the residual gas passing through the first branch 150. A second valve 152 is provided on the front section of the oxygen pipeline 123 at the connection with the first branch 150. The front section of the oxygen pipeline 123, that is, the part of the oxygen pipeline 123 extending from the connection between the oxygen pipeline 123 and the first branch 150 to the oxygen storage tank 121. Similarly, the rear section of the oxygen pipeline 123 to be mentioned below, that is, the part of the oxygen pipeline 123 extending from the connection between the oxygen pipeline 123 and the first branch 150 to the burner 111.

[0049] The first valve 151 and the second valve 152 remix the pure oxygen and the residual gas through their respective openings to make the decomposition furnace 110 calcined in a reducing atmosphere, wherein the pure oxygen accounts for 17%-18% of the remixed pure oxygen and the residual gas.

[0050] In the prior art, air is used as a combustion-supporting gas. When it is directly mixed with fuel and then burned, it cannot guarantee a reducing atmosphere. Therefore, if clay is to be in a reducing atmosphere during calcination, the prior art usually injects additional reducing gas, which undoubtedly requires the addition of other equipment, making the structure more complicated and increasing the cost. However, this embodiment simply adjusts the oxygen ratio by "dividing and combining" the air, so that the decomposition furnace 110 can be in a reducing atmosphere during clay calcination. The structure is simple, the conception is ingenious, and it has unexpected effects.

[0051] According to the treatment system 100 of the present invention, the membrane separation oxygen production device 120 is used to separate air into pure oxygen and residual gas, and a part of the residual gas is re-mixed with pure oxygen and transported to the burner 111 for combustion, so that the decomposition furnace 110 is in a reducing atmosphere for calcination; another part of the residual gas is transported into the cooling device 140 as cooling air to exchange heat with the clinker generated by calcining clay in the decomposition furnace 110, so as to ensure that the clinker is cooled in an oxygen-free environment and prevent the clinker from being recolored due to the presence of oxygen; and the residual gas after heat exchange with the clinker in the cooling device 140 finally enters the decomposition furnace 110, further ensuring that the decomposition furnace 110 is in a reducing atmosphere; at the same time, before the clay enters the decomposition furnace 110, it exchanges heat with the flue gas generated by calcining clay in the decomposition furnace 110 in the preheating device 130. The entire treatment system 100 directly uses the most easily available air in nature, and can keep the color of the clinker gray when calcining and cooling the clinker at the same time, with a simple structure and low energy consumption.

[0052] refer to Figure 1 In order to provide a preheating device 130 with good heat exchange effect, the preheating device 130 may include a plurality of cyclones 170 arranged from top to bottom, such as 3, 4 or other reasonable number of cyclones 170. The bottom material outlet of the lowest cyclone 170 is connected to the cooling device 140. The gas inlet of the lowest cyclone 170 is connected to the decomposition furnace 110. The material gas (i.e., clinker and flue gas) generated by calcining clay in the decomposition furnace 110 enters the lowest cyclone 170, and the clinker is transported from the bottom material outlet to the cooling device 140 after the material gas is separated in the cyclone 170. The high-temperature flue gas enters the upper cyclone 170 from the top gas outlet. The top gas outlet of the upper cyclone 170 is connected to the exhaust gas duct 160. The bottom material outlet of the upper cyclone 170 adjacent to the lowest cyclone 170 is connected to the decomposition furnace 110. The gas outlet of the cyclone 170 at the bottom is connected to the cyclone 170 at the top through the connecting pipe 171, and the bottom material outlet of the cyclone 170 at the top is connected to the connecting pipe 171 at the bottom. The clay (before calcination) entering the preheating device 130 will be lifted by the airflow in the connecting pipe 171 and will be in a suspended state. After sufficient heat exchange with the hot airflow, it will enter the decomposition furnace 110 to complete the calcination process.

[0053] The raw material is fed into the uppermost connecting pipe 171. In order to reduce the height of the entire cyclone 170 device (preheating device 130), the uppermost cyclone 170 can be arranged as two cyclones 170.

[0054] Continue to refer Figure 1 In order to provide a cooling device 140 with good cooling effect, the cooling device 140 may also include a plurality of cyclones 170 arranged from top to bottom, such as 3, 4 or other reasonable number of cyclones 170. The bottom material outlet of the cyclone 170 located at the bottom is connected to the zipper machine 192 or other equipment. The gas inlet of the cyclone 170 located at the bottom is connected to the by-product pipeline 124, and the residual gas transported in the by-product pipeline 124 is used as cooling air to exchange heat with the clinker. The top gas outlet of the cyclone 170 located at the top is connected to the decomposition furnace 110, and the residual gas after heat exchange with the clinker all enters the decomposition furnace 110. Among them, the gas outlet of the cyclone 170 located at the bottom is connected to the cyclone 170 located at the top through the connecting pipe 171. The bottom material outlet of the cyclone 170 located at the top is connected to the connecting pipe 171 at the bottom. Similarly, the clinker entering the cooling device 140 will be lifted by the airflow in the connecting pipe 171 and kept in a suspended state. After sufficient heat exchange with the remaining gas, it will eventually be transported to the zipper machine 192 or other equipment to be made into a finished product.

[0055] It can be understood that the clinker discharged from the preheating device 130 (i.e., the lowest cyclone 170 in the preheating device 130) is fed into the connecting pipe 171 located at the top.

[0056] Generally, the final waste gas of the preheating device 130 can be discharged from the chimney 191 through the exhaust pipe 160 after a series of gas treatments through the blower. In a preferred embodiment, in order to reasonably utilize the waste gas discharged from the preheating device 130, the waste pipe 160 can also be provided with a second branch 182 on the rear section of the pipe connected to the connection between the oxygen pipe 123 and the first branch 150. The second branch 182 is provided with a corresponding valve. In this way, the waste gas can at least partially replace the by-product gas and mix with pure oxygen to control the oxygen content in the decomposition furnace 110. Under the effect of calcination in a reducing atmosphere in the decomposition furnace 110, more residual gas is allowed to participate in cooling the clinker, so that the temperature of the clinker is further reduced, and the use requirements of the subsequent process are met.

[0057] In order to further improve the utilization rate of waste gas, the waste gas pipeline 160 can also be provided with a third branch 183 connected to the by-product pipeline 124. The third branch 183 is provided with a corresponding valve. In this embodiment, since the waste gas does not contain oxygen, the waste gas can be transported to the by-product pipeline 124 and used as cooling gas, and heat exchange is performed with the high-temperature clinker in the cooling device 140, thereby reducing the use of residual gas, thereby reducing the oxygen production time and power consumption of the membrane separation oxygen production device 120.

[0058] In order to reduce the amount of pure oxygen used, the processing system 100 may also include a fourth branch 184. The fourth branch 184 is arranged on the rear section of the pipeline at the connection between the oxygen pipeline 123 and the first branch 150. The fourth branch 184 is provided with a corresponding valve for introducing air. In this way, the air transported through the fourth branch 184 can partially replace the pure oxygen, and then adjust the final oxygen content by mixing with the remaining gas transported by the first branch 150, so as to achieve calcination in a reducing atmosphere in the decomposition furnace 110. It can be understood that through the above arrangement, the oxygen production time and power consumption of the membrane separation oxygen production device 120 can also be reduced.

[0059] In a second aspect, the present invention further provides a method for treating suspended calcined clay, based on the treatment system 100 of the above technical solution. The treatment method specifically comprises the following steps:

[0060] The membrane separation oxygen production device 120 separates air into pure oxygen and residual gas, and the separated pure oxygen and residual gas are transported to the oxygen storage tank 121 and the by-product storage tank 122 respectively.

[0061] A portion of the remaining gas in the by-product storage tank 122 is re-adjusted with the pure oxygen in the oxygen storage tank 121 through the respective openings of the first valve 151 and the second valve 152 and transported to the burner 111 to be mixed with the fuel and burned, so that the decomposition furnace 110 is in a reducing atmosphere for calcination.

[0062] Another part of the residual gas in the by-product storage tank 122 is transported to the cooling device 140 as cooling air to exchange heat with the clinker generated by calcining clay in the decomposition furnace 110, so as to ensure that the clinker is cooled in an oxygen-free environment and prevent the clinker from being re-colored due to the presence of oxygen; and the residual gas in the cooling device 140 after heat exchange with the clinker finally enters the decomposition furnace 110, further ensuring that the decomposition furnace 110 is in a reducing atmosphere.

[0063] Before the clay enters the decomposition furnace 110 for calcination, it is preheated by heat exchange with the flue gas generated by the decomposition furnace 110 for calcination of the clay in the preheating device 130.

[0064] Other embodiments of the present invention will be readily apparent to those skilled in the art from the description and practice of the invention disclosed herein. The description and embodiments are to be considered exemplary only, and the true scope and spirit of the present invention are to be limited by the claims.

Claims

1. A system for treating suspended calcined clay, characterized in that: The processing system comprises: A calciner for calcining clay, the calciner being connected to a burner provided with a gas inlet and a fuel inlet; the calciner is also provided with an alternative fuel inlet; A membrane separation oxygen production device is used to separate air into pure oxygen and residual gas, and the separated pure oxygen and residual gas are respectively transported to an oxygen storage tank and a by-product storage tank; wherein the oxygen storage tank is connected to the gas inlet via an oxygen pipeline, and the by-product storage tank is connected to the by-product pipeline; a preheating device connected to the decomposition furnace, used for heat exchange between clay and flue gas generated by calcining clay in the decomposition furnace, the preheating device comprising a clay inlet for introducing clay, a clay outlet for leading the clay after heat exchange to the decomposition furnace, and a first clinker outlet for leading clinker generated by calcining clay in the decomposition furnace; A cooling device connected to the by-product pipeline and the first clinker outlet, respectively, is used for heat exchange between the clinker and the residual gas transported by the by-product pipeline in an oxygen-free environment to prevent the clinker from being recolored due to the presence of oxygen when the temperature is lowered; the cooling device includes a gas outlet for leading the residual gas after heat exchange to the decomposition furnace and a second clinker outlet for leading the clinker after heat exchange; a first branch, one end of the first branch being connected to the byproduct pipeline, the other end of the first branch being connected to the oxygen pipeline, the first branch being provided with a first valve, and the oxygen pipeline being provided with a second valve on a front section of the pipeline at a connection with the first branch; A fourth branch is provided on the rear section of the pipeline at the connection between the oxygen pipeline and the first branch, and the fourth branch is provided with a corresponding valve for introducing air; The first valve and the second valve remix pure oxygen and residual gas through their respective openings and deliver them to the burner, so that the decomposition furnace is in a reducing atmosphere for calcination, wherein the pure oxygen volume ratio of the remixed pure oxygen and residual gas is 17%-18%; The remaining gas after heat exchange with the clinker in the cooling device enters the decomposition furnace through the gas outlet, further ensuring that the decomposition furnace is in a reducing atmosphere.

2. The processing system according to claim 1, characterized in that The preheating device comprises a plurality of cyclones arranged from top to bottom, the bottom material outlet of the cyclone located at the bottom is connected to the cooling device, the gas inlet of the cyclone located at the bottom is connected to the decomposition furnace, the top gas outlet of the cyclone located at the top is connected to the exhaust gas pipe, and the bottom material outlet of the cyclone located above and adjacent to the bottom cyclone is connected to the decomposition furnace; wherein the gas outlet of the cyclone located below is connected to the cyclone located above through a connecting pipe, and the bottom material outlet of the cyclone located above is connected to the connecting pipe below; The raw material is fed into the connecting pipe located at the top.

3. The processing system according to claim 2, characterized in that The cooling device also includes a plurality of cyclones arranged from top to bottom, the bottom material outlet of the cyclone located at the bottom is connected to the zipper machine, the gas inlet of the cyclone located at the bottom is connected to the by-product pipeline, and the top gas outlet of the cyclone located at the top is connected to the decomposition furnace; wherein the gas outlet of the cyclone located at the bottom is connected to the cyclone located at the top through a connecting pipeline, and the bottom material outlet of the cyclone located at the top is connected to the connecting pipeline at the bottom; The clinker discharged from the preheating device is put into the connecting pipe located at the top.

4. The processing system according to claim 3, characterized in that The exhaust gas pipeline is also provided with a second branch on the rear section of the pipeline connected to the connection between the oxygen pipeline and the first branch, and the second branch is provided with a corresponding valve.

5. The processing system according to claim 4, characterized in that The exhaust gas pipeline is also provided with a third branch connected to the by-product pipeline, and the third branch is provided with a corresponding valve.

6. A method for treating suspended calcined clay, based on the treatment system according to any one of claims 1 to 5, characterized in that: The processing method comprises: The membrane separation oxygen production device separates air into pure oxygen and residual gas, and the separated pure oxygen and residual gas are transported to the oxygen storage tank and the by-product storage tank respectively; A portion of the remaining gas in the by-product storage tank is re-adjusted with the pure oxygen in the oxygen storage tank through the opening of the first valve and the second valve and transported to the burner to be mixed with the fuel and burned, so that the decomposition furnace is in a reducing atmosphere for calcination; The remaining gas in the by-product storage tank is transported to the cooling device as cooling air to exchange heat with the clinker generated by calcining clay in the decomposition furnace, so as to ensure that the clinker is cooled in an oxygen-free environment and prevent the clinker from being recolored due to the presence of oxygen; and the remaining gas in the cooling device after heat exchange with the clinker finally enters the decomposition furnace, further ensuring that the decomposition furnace is in a reducing atmosphere; Before the clay enters the decomposition furnace for calcination, it is preheated by heat exchange with the flue gas generated by the decomposition furnace for calcination of the clay.

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