Treatment method and system for suspension calcination of clay

Abstract

The present disclosure provides a treatment method and system for suspension calcination of clay. The treatment system comprises: a decomposition furnace connected to a combustor; a membrane separation oxygen generation device, separated pure oxygen and residual gas being conveyed to an oxygen storage tank and a byproduct storage tank, respectively; a preheating device, used for carrying out heat exchange between clay and flue gas generated in calcination of clay in the decomposition furnace; a cooling device, used for carrying out heat exchange between a clinker and the residual gas conveyed by a byproduct pipeline; and a first branch having one end communicated with the byproduct pipeline and the other end communicated with an oxygen pipeline, the first branch being provided with a first valve, a second valve being provided on a front-section pipeline of the oxygen pipeline, and the first valve and the second valve readjusting a pure oxygen and residual gas mixing amount, so that calcination is performed in the decomposition furnace in a reducing atmosphere. According to the treatment system provided by the present disclosure, simply by using air, the color of the clinker can be kept gray when the clinker is obtained by calcination and the clinker is cooled.

Description

Method and system for treating suspended calcined clay

[0001] Related applications

[0002] This disclosure claims priority to Chinese patent application number CN202311241427.6, filed with the Patent Office of China on September 25, 2023, entitled “Method and system for treating suspended calcined clay,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of cement calcination, and in particular to a method and system for treating suspended calcined clay. Background Art

[0004] The cement manufacturing industry is central to global infrastructure development, just like every energy-intensive industry. The production process for Portland cement is representative of this industry. Limestone and clay are the primary raw materials, which are crushed, batched, and ground into raw meal. This is then fed into a cement kiln and calcined into clinker. The clinker is then ground into a suitable amount of gypsum (and sometimes mixed materials or admixtures). Cement production generally consists of three steps: raw meal preparation, clinker calcination, and cement production. Depending on the raw meal preparation method, cement production can be categorized into two types: dry process (including semi-dry process) and wet process (including semi-wet process).

[0005] Among them, if the clay is in a reducing atmosphere during calcination, the finished product is gray. After being 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 being added to clinker and ground into cement, it will affect the color of the cement.

[0006] In the process of implementing the present disclosure, the inventors discovered that the prior art has at least the following problems:

[0007] When producing cement using the dry process, the raw materials are generally dried and ground simultaneously, or first dried and ground into raw meal before being fed into a dry kiln for calcination into clinker. The raw materials (clay) are calcined in the dry kiln by adding fuel and introducing air for combustion to provide heat. Air, the most readily available gas in nature, does not guarantee a reducing atmosphere when directly mixed with fuel and then burned. Therefore, currently, to achieve a reducing atmosphere for the clay during calcination, additional reducing gas is usually injected. This undoubtedly requires the addition of additional equipment, resulting in a more complex structure and increased costs. In addition, the clinker generated by the calcination of the raw materials (clay) needs to be cooled to prepare it for subsequent cement production. If the clinker comes into contact with oxygen during cooling, it will recolor, affecting the final color of the cement.

[0008] Therefore, a method and system for treating suspended calcined clay are needed to at least partially solve the above technical problems.

[0009] Summary of the Invention

[0010] The embodiments of the present disclosure provide a method and system for treating suspended calcined clay, which has a simple structure, directly utilizes the most readily available air in nature, and keeps the clinker color gray while simultaneously completing the calcination and cooling of the clinker.

[0011] In a first aspect, the present disclosure provides a system for processing suspended calcined clay, comprising:

[0012] a calciner for calcining clay, said calciner being connected to a burner provided with a gas inlet and a fuel inlet;

[0013] a membrane separation oxygen production device, configured to separate air into pure oxygen and residual gas, and to deliver the separated pure oxygen and residual gas to an oxygen storage tank and a by-product storage tank, respectively; 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;

[0014] a preheating device connected to the calciner, used for exchanging heat between clay and flue gas generated by calcining the clay in the calciner, the preheating device comprising a clay inlet for introducing clay, a clay outlet for leading the clay after heat exchange to the calciner, and a first clinker outlet for leading clinker generated by calcining the clay in the calciner;

[0015] a cooling device connected to the by-product pipeline and the first clinker outlet, respectively, for exchanging heat between the clinker and the residual gas transported from the by-product pipeline, the cooling device comprising a gas outlet for leading the residual gas after heat exchange to the calciner and a second clinker outlet for leading the clinker after heat exchange;

[0016] a first branch, one end of the first branch being connected to the by-product pipeline, the other end of the first branch being connected to the oxygen pipeline, a first valve being provided on the first branch, and a second valve being provided on the oxygen pipeline at the upstream portion of the connection with the first branch;

[0017] 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.

[0018] The treatment system disclosed herein utilizes a membrane separation oxygen generator to separate air into pure oxygen and residual gas. A portion of the residual gas is remixed with pure oxygen and delivered to a burner for combustion, maintaining a reducing atmosphere within the decomposition furnace. Another portion of the residual gas is delivered as cooling air to a cooling device, where it exchanges heat with the clinker generated by calcining clay in the decomposition furnace. This ensures that the clinker is cooled in an oxygen-free environment and prevents recoloration due to the presence of oxygen. Furthermore, the residual gas, after heat exchange with the clinker in the cooling device, finally enters the decomposition furnace, further ensuring a reducing atmosphere within the decomposition furnace. Furthermore, before the clay enters the decomposition furnace, it undergoes heat exchange with the flue gas generated by the calcination of clay in the decomposition furnace within a preheating device. The entire treatment system directly utilizes the most readily available air in nature, maintaining the clinker's gray color while simultaneously calcining and cooling it. It has a simple structure and low energy consumption.

[0019] Optionally, the preheating device includes 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 cyclone located above and 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 via a connecting pipe, and the bottom material outlet of the upper cyclone is connected to the lower connecting pipe;

[0020] The raw material is fed into the connecting pipe located at the top.

[0021] Optionally, the cooling device also includes a plurality of cyclones arranged from top to bottom, wherein the bottom material outlet of the lowest cyclone is connected to a zipper machine or other equipment, the gas inlet of the lowest cyclone is connected to the by-product pipeline, and the top gas outlet of the highest cyclone is connected to the decomposition furnace; wherein the gas outlet of the lower cyclone is connected to the upper cyclone via a connecting pipeline, and the bottom material outlet of the upper cyclone is connected to the lower connecting pipeline;

[0022] The clinker discharged from the preheating device is fed into the connecting pipe located at the top.

[0023] 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.

[0024] 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.

[0025] Optionally, the treatment system further comprises: a fourth branch provided on a rear section of the pipeline at a connection between the oxygen pipeline and the first branch, the fourth branch being provided with a corresponding valve for introducing air.

[0026] Optionally, the calciner is further provided with an alternative fuel inlet.

[0027] In a second aspect, the present disclosure further provides a method for treating suspended calcined clay, and the treatment system based on the above technical solution specifically comprises the following steps:

[0028] The membrane separation oxygen production device separates the 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;

[0029] A portion of the remaining gas in the by-product storage tank is mixed with the pure oxygen in the oxygen storage tank through the opening of the first valve and the second valve, and then transported to the burner to mix with the fuel and burn, so that the decomposition furnace is in a reducing atmosphere for calcination;

[0030] The remaining gas in the by-product storage tank is transported as cooling air to the cooling device to exchange heat with the clinker generated by calcining clay in the decomposition furnace, ensuring that the clinker is cooled in an oxygen-free environment and preventing the clinker from re-coloring due to the presence of oxygen. In addition, 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.

[0031] Before the clay enters the decomposition furnace for calcination, it is preheated by exchanging heat with the flue gas generated by the decomposition furnace for calcination.

[0032] By utilizing the technical solution according to the embodiments of the present disclosure, the beneficial effects that can be obtained are at least:

[0033] 1. A membrane separation oxygen generator is used to separate air into pure oxygen and residual gas. A portion of the residual gas is re-mixed with pure oxygen and transported to the burner for combustion, creating a reducing atmosphere for calcination in the decomposition furnace. Another portion of the residual gas is transported as cooling air to the cooling device to exchange heat with the clinker generated by calcining clay in the decomposition furnace, ensuring that the clinker is cooled in an oxygen-free environment and preventing the clinker from recoloring due to the presence of oxygen. Furthermore, 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 utilizes the most readily available air in nature, and can simultaneously complete the calcination and cooling of the clinker while keeping the clinker gray in color.

[0034] 2. Before the clay enters the decomposition furnace, it exchanges heat with the flue gas generated by the decomposition furnace in the preheating device. The entire treatment system has a simple structure and low energy consumption.

[0035] Additional advantages, objects, and features of the present disclosure will be described in part in the following description and will become apparent to those skilled in the art upon study of the following or may be learned from practice of the present disclosure. The objects and other advantages of the present disclosure may be achieved and obtained by the structures specifically pointed out in the description and drawings.

[0036] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present disclosure are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present disclosure will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are intended to provide a further understanding of the present disclosure, constitute a part of the present disclosure, and do not constitute a limitation of the present disclosure. The components in the drawings are not drawn to scale, but are only for the purpose of illustrating the principles of the present disclosure. To facilitate the illustration and description of some parts of the present disclosure, the corresponding parts in the drawings may be enlarged, that is, they may be larger than other parts in the exemplary devices actually manufactured according to the present disclosure. In the drawings:

[0038] FIG1 is an overall schematic diagram of a system for processing suspended calcined clay according to an embodiment of the present disclosure.

[0039] Explanation of the accompanying drawings: 100, treatment 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, exhaust gas pipeline; 170, cyclone; 171, connecting pipeline; 182, second branch; 183, third branch; 184, fourth branch; 191, chimney; 192, zipper machine. DETAILED DESCRIPTION

[0040] The purposes and functions of the present disclosure, as well as methods for achieving these purposes and functions, will be clarified by reference to exemplary embodiments. However, the present disclosure is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The essence of the description is merely to help those skilled in the relevant art to comprehensively understand the specific details of the present disclosure.

[0041] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. 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, they indicate the presence of features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0042] Ordinal numbers such as “first” and “second” cited in the present disclosure are merely identifiers 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 a “second component”, and the term “second component” itself does not imply the existence of a “first component”.

[0043] 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.

[0044] In one aspect, the present disclosure 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 ensuring that the color of calcined clay raw materials and cooled clinker is gray.

[0045] As shown in Figure 1, in a preferred embodiment, the processing system 100 includes a decomposition furnace 110, a membrane separation oxygen generator 120, a preheating device 130, a cooling device 140, and a first branch 150. The decomposition furnace 110 serves as the clay calcining device. The membrane separation oxygen generator 120 is used to separate air into pure oxygen and residual gas. The preheating device 130 is used to preheat the clay. The cooling device 140 is used to cool the clinker produced by calcination. The first branch 150 is used to remix the residual gas with pure oxygen, changing the proportion of pure oxygen (oxygen).

[0046] Specifically, the calciner 110 is used to calcine clay, allowing the clay to be calcined into clinker in the heat provided by the combustion of fuel. The calciner 110 is a commonly used calcining device in the art, and its specific structure is not described here. The calciner 110 is connected to a burner 111, which is equipped with a gas inlet and a fuel inlet. To ensure the normal operation of the calciner 110, the calciner 110 can also be equipped with an alternative fuel inlet (AFR inlet), which can partially or completely replace the fuel fed to the fuel inlet of the burner 111.

[0047] 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. 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 to be 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 stored for use. 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 shut down 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.

[0048] Preheating device 130 is connected to calciner 110 and is used to exchange heat between clay and the flue gas generated by calcining the clay in calciner 110. Preheating device 130 includes a clay inlet for introducing clay, a clay outlet for discharging the heat-exchanged clay into calciner 110, and a first clinker outlet for discharging the clinker generated by calcining the clay in calciner 110. The clinker generated by calcining the clay in calciner 110 is discharged to cooling device 140 through the first clinker outlet. Preheating device 130 can utilize existing technology.

[0049] 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 from the by-product pipeline 124. The cooling device 140 includes a gas outlet for directing the residual gas after heat exchange to the decomposition furnace 110 and a second clinker outlet for directing the clinker after heat exchange. Of course, the cooling device 140 also includes a port for receiving the residual gas transported from the by-product pipeline 124 and a port for receiving clinker. The cooling device 140 may also employ a conventional device. When the clinker is cooled, if oxygen is present, a phase transition from magnetite to hematite occurs, and the color of the clinker changes from gray to other colors. The residual gas transported through the by-product pipeline 124 cools the clinker. Since oxygen is stripped from the by-product (residual gas) of the membrane separation oxygen production device 120, when it acts as cooling air, the finished product can be cooled to below 120°C, and there is no color change during the process, i.e., the color of the finished product is gray.

[0050] One end of the first branch 150 is connected to the by-product pipeline 124 for introducing some of the excess gas. The other end of the first branch 150 is connected to the oxygen pipeline 123 for mixing the introduced excess gas with pure oxygen. A first valve 151 is provided on the first branch 150 to regulate the flow of excess gas through the first branch 150. A second valve 152 is provided on the section of oxygen pipeline 123 preceding the connection with the first branch 150. The preceding section of oxygen pipeline 123, i.e., the section extending from the connection between oxygen pipeline 123 and the first branch 150 to the oxygen storage tank 121, is referred to as the subsequent section of oxygen pipeline 123, i.e., the section extending from the connection between oxygen pipeline 123 and the first branch 150 to the burner 111.

[0051] 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.

[0052] In the prior art, air, as a combustion-supporting gas, cannot guarantee a reducing atmosphere when directly mixed with fuel and then burned. Therefore, to achieve a reducing atmosphere during clay calcination, the prior art typically requires additional injection of reducing gas, which undoubtedly requires additional equipment, complicates the structure, and increases costs. However, this embodiment achieves a reducing atmosphere within the decomposition furnace 110 during clay calcination by simply dividing and combining the air, adjusting the oxygen content. This simple structure, ingenious design, and unexpected results yield impressive results.

[0053] According to the treatment system 100 disclosed herein, a membrane separation oxygen generator 120 separates air into pure oxygen and residual gas. A portion of the residual gas is remixed with pure oxygen and transported to the burner 111 for combustion, maintaining a reducing atmosphere within the decomposition furnace 110. Another portion of the residual gas is transported as cooling air to the cooling device 140, where it exchanges heat with the clinker generated by calcining clay in the decomposition furnace 110. This ensures that the clinker is cooled in an oxygen-free environment and prevents recoloration due to the presence of oxygen. Furthermore, the residual gas in the cooling device 140, after heat exchange with the clinker, finally enters the decomposition furnace 110, further ensuring a reducing atmosphere within the decomposition furnace 110. Furthermore, before entering the decomposition furnace 110, the clay undergoes heat exchange with the flue gas generated by the calcination of clay in the decomposition furnace 110 in the preheating device 130. The entire treatment system 100 directly utilizes the most readily available air in nature, maintaining the clinker's gray color while simultaneously calcining and cooling it. It has a simple structure and low energy consumption.

[0054] Referring to FIG1 , to provide a preheating device 130 with improved heat exchange, the preheating device 130 may include multiple cyclones 170 arranged from top to bottom, for example, three, four, or another 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 gas (i.e., clinker and flue gas) generated by calcining clay in the decomposition furnace 110 enters the lowest cyclone 170. After separation of the gas and the material in the cyclone 170, the clinker is transported from the bottom material outlet to the cooling device 140. 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 lower cyclone 170 is connected to the upper cyclone 170 via a connecting pipe 171. The bottom material outlet of the upper cyclone 170 is connected to the lower connecting pipe 171. The clay (before calcination) entering the preheating device 130 is lifted and suspended by the airflow in the connecting pipe 171. After sufficient heat exchange with the hot airflow, it enters the decomposition furnace 110 to complete the calcination process.

[0055] 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 into two cyclones 170.

[0056] Continuing to refer to FIG1 , 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 lowest cyclone 170 is connected to the zipper machine 192 or other equipment. The gas inlet of the lowest cyclone 170 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 highest cyclone 170 is connected to the decomposition furnace 110, and the residual gas after heat exchange with the clinker all enters the decomposition furnace 110. The gas outlet of the lower cyclone 170 is connected to the upper cyclone 170 through the connecting pipe 171. The bottom material outlet of the upper cyclone 170 is connected to the lower connecting pipe 171. Similarly, the clinker entering the cooling device 140 will be lifted by the air flow in the connecting pipe 171 and kept in a suspended state. After sufficient heat exchange with the remaining gas, it will be finally transported to the zipper machine 192 or other equipment to be made into a finished product.

[0057] It can be understood that the clinker discharged from the preheating device 130 (i.e., the cyclone 170 at the bottom of the preheating device 130) is fed into the connecting pipe 171 at the top.

[0058] Generally, the final exhaust gas from the preheating device 130 can pass through the exhaust pipe 160 and undergo a series of gas treatments before being discharged from the chimney 191 through a blower. In a preferred embodiment, in order to rationally utilize the exhaust gas discharged from the preheating device 130, the exhaust 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 exhaust 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. While achieving the effect of calcining in a reducing atmosphere in the decomposition furnace 110, more residual gas can be used to cool the clinker, thereby causing the clinker to cool further and meet the requirements of subsequent processes.

[0059] To further improve waste gas utilization, waste gas pipeline 160 may also be provided with a third branch 183 connected to by-product pipeline 124. Third branch 183 is equipped with a corresponding valve. In this embodiment, since the waste gas also does not contain oxygen, it can be transported to by-product pipeline 124 and used as cooling gas. Heat exchange with the high-temperature clinker in cooling device 140 reduces the use of excess gas, thereby reducing the oxygen production time and power consumption of membrane separation oxygen generator 120.

[0060] To reduce pure oxygen usage, the processing system 100 may further include a fourth branch 184. The fourth branch 184 is disposed on the downstream pipeline at the junction of the oxygen pipeline 123 and the first branch 150. A valve is provided in the fourth branch 184 for introducing air. The air delivered through the fourth branch 184 can partially replace the pure oxygen, and then, by mixing with the remaining gas delivered by the first branch 150, the final oxygen content is adjusted to achieve a reducing atmosphere in the decomposition furnace 110. It will be appreciated that the above arrangement can also reduce the oxygen production time and power consumption of the membrane separation oxygen production device 120.

[0061] In a second aspect, the present disclosure 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:

[0062] 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.

[0063] A portion of the remaining gas in the by-product storage tank 122 is mixed 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, mixed with the fuel and burned, so that the decomposition furnace 110 is in a reducing atmosphere for calcination.

[0064] Another part of the residual gas in the by-product storage tank 122 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 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.

[0065] 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 during calcination of the clay in the preheating device 130 .

[0066] Other embodiments of the present disclosure will be readily apparent to those skilled in the art from the description and practice of the present disclosure disclosed herein. The description and embodiments are intended to be exemplary only, with the true scope and spirit of the present disclosure being defined 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; 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, 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; 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; 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.

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 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; 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. The processing system according to claim 5, characterized in that Also includes: A fourth branch is arranged on the rear section of the pipeline at the connection between the oxygen pipeline and the first branch, and a corresponding valve is arranged on the fourth branch for introducing air.

7. The processing system according to claim 1, characterized in that The calciner is also provided with an alternative fuel inlet.

8. A method for treating suspended calcined clay, based on the treatment system according to any one of claims 1 to 7, 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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