Clay calcination color control system
By combining a vertical decomposition furnace, a hot air furnace, a collecting cyclone, and a color restoration device, the problem of color control in clay calcination was solved, achieving stability and environmental friendliness in clay calcination color, and improving production efficiency and heat utilization.
Patent Information
- Application Number
- CN202520454267.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-03-14
AI Technical Summary
Existing clay calcination technology has difficulty in effectively controlling the calcination color, especially since iron content is oxidized to red during combustion, resulting in uneven product color and making it difficult to guarantee the production of gray products.
A combined system consisting of a vertical decomposition furnace, a hot air furnace, a collecting cyclone, an air-cooled rotary cooler, and a color reduction device is used to control the color change of clay materials through calcination in an oxidizing atmosphere, reduction by reducing gas, and non-contact cooling.
This method effectively controls the color of calcined clay, resulting in a stable gray-black product color, which reduces carbon dioxide emissions and improves heat utilization and production efficiency.
Smart Images
Figure CN223925402U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of clay calcination technology, and in particular to a clay calcination color control system. Background Technology
[0002] The powdered calcined products formed through calcination vary across different industries. In the cement production industry, calcined clay is a common example.
[0003] Calcined clay possesses many excellent properties, such as high toughness, high compressive strength, and good thermal stability, and is often used to make pottery, porcelain, and other handicrafts. In addition, calcined clay is widely used in medicine, food, chemicals, building materials, and environmental protection.
[0004] In the process of realizing this utility model, the inventors discovered that the prior art has at least the following problems:
[0005] Clay calcination technology, due to its inherent characteristics, does not produce carbon dioxide during calcination; only the fuel itself generates waste gas. Compared to ordinary cement clinker, it can reduce carbon dioxide emissions by 40%, thus its application and promotion are increasingly widespread. However, due to the diversity of clay and its high elemental content, especially iron, it oxidizes to a red color during combustion, unlike traditional cement ash. Therefore, the production process needs to be controlled to ensure the product is gray.
[0006] Therefore, a clay calcination color control system is needed to at least partially solve the above-mentioned technical problems. Utility Model Content
[0007] This utility model provides a clay calcination color control system, which has a simple structure and can realize the color control of clay calcination.
[0008] This utility model provides a clay calcination color control system, the control system comprising:
[0009] A vertical decomposition furnace is used for calcining clay raw materials in an oxidizing atmosphere;
[0010] A hot air furnace is used to burn fuel; wherein the hot air furnace is connected to the air inlet at the bottom of the decomposition furnace via a heating pipe to provide the decomposition furnace with clay calcination heat;
[0011] A collecting cyclone separator is used to separate the high-temperature clay material and waste gas generated from the calcination of clay raw materials in the decomposition furnace;
[0012] An air-cooled rotary cooler includes a rotary cylinder rotatable about a horizontal axis. Multiple cooling tubes, rotating axially with the cylinder, are arranged inside the cylinder. Cooling air is injected into the cooling tubes to achieve non-contact heat exchange between the cooling air and the clay material. The inlet of the rotary cylinder is connected to the outlet of the collecting cyclone via a feed pipe.
[0013] The color reduction device arranged in the feed pipeline includes a sealed housing connected to the feed pipeline; the housing has an inlet at the bottom for filling with reducing gas and an outlet at the top for exhausting gas, for reducing clay material falling from above into the housing.
[0014] According to the control system of this invention, clay raw materials are fully calcined in a decomposition furnace under an oxidizing atmosphere, where the iron content is converted into Fe2O3, resulting in a reddish-brown color. After separation by a collecting cyclone separator, the clay enters a color reduction device. A reducing gas (such as CO) is injected from the bottom of the color reduction device, and the rising reducing gas comes into full contact with the falling clay material, reducing the Fe2O3 in the clay to Fe3O4, resulting in a grayish-black color. Next, the clay material enters an air-cooled rotary cooler. Cooling air is injected through multiple steel pipes fixed inside the air-cooled rotary cooler, allowing indirect heat exchange between the cooling gas and the calcined clay material. The cooling gas is heated to 450°C, while the calcined clay material can be cooled to approximately 100°C. Inside the air-cooled rotary cooler, the calcined clay material does not come into contact with the cooling gas or outside air, ensuring that the clay material is not oxidized during the cooling process, thus achieving color control of the calcined clay.
[0015] Optionally, the control system further includes a multi-stage suspension preheating cyclone for preheating the clay raw material to be calcined; wherein the feed inlet of the lowest stage of the multi-stage suspension preheating cyclone is connected to the decomposition furnace via a feed pipeline, and the feed inlet of the lowest stage of the multi-stage suspension preheating cyclone is connected to the air outlet of the collecting cyclone.
[0016] Additional advantages, objects, and features of this invention will be set forth in part in the description which follows, and will in part become apparent to those skilled in the art upon review of the description, or may be learned by practice of the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.
[0017] Those skilled in the art will understand that the objectives and advantages achievable with this invention are not limited to those specifically described above, and that the above and other objectives achievable with this invention will become clearer from the following detailed description. Attached Figure Description
[0018] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, do not constitute a limitation thereof. The components in the drawings are not drawn to scale but are merely for illustrating the principles of the present invention. For ease of illustration and description of certain parts of the present invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the present invention. In the drawings:
[0019] Figure 1 This is a schematic diagram of the overall control system according to an embodiment of the present invention.
[0020] Explanation of reference numerals in the attached figures:
[0021] 100. Control system;
[0022] 110. Decomposition furnace; 111. Supplemental fuel inlet;
[0023] 120. Hot air furnace; 121. Heating pipeline;
[0024] 130. Collect the cyclone tubes;
[0025] 140. Air-cooled rotary cooler; 141. Rotary drum;
[0026] 150. Feed pipe;
[0027] 160. Color restoration device; 161. Housing;
[0028] 170. Multi-stage suspended preheating cyclone separator; 171. Preheating cyclone separator;
[0029] 181. First branch pipe; 182. Second branch pipe; 183. Third branch pipe; 184. Fourth branch pipe; 185. Circulation pipe; 186. Exhaust gas pipe; 187. Exhaust pipe;
[0030] 191. First airlock valve; 192. Second airlock valve; 193. Material distribution valve. Detailed Implementation
[0031] The objectives and functions of this invention, as well as the methods for achieving these objectives and functions, will be clarified by referring to exemplary embodiments. However, this invention is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The purpose of this specification is merely to help those skilled in the art to comprehensively understand the specific details of this invention.
[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.
[0033] The ordinal numbers such as "first" and "second" used in this invention are merely identifiers and have no other meaning, such as a specific order. Furthermore, for example, the term "first component" does not imply the existence of "second component," and the term "second component" does not imply the existence of "first component."
[0034] It should be noted that the terms “up,” “down,” “front,” “back,” “left,” “right,” “inner,” “outer,” and similar expressions used in this article are for illustrative purposes only and are not intended to be limiting.
[0035] This invention provides a clay calcination color control system 100. The control system 100 can be applied to clay calcination, for example, and can solve the problem of poor color control in existing clay calcination methods.
[0036] In a preferred embodiment, refer to Figure 1 As shown, Figure 1 This is a schematic diagram of the overall control system according to an embodiment of the present invention. The control system 100 provided in this embodiment of the present invention includes a decomposition furnace 110, a hot air furnace 120, a collecting cyclone 130, an air-cooled rotary cooler 140, and a color restoration device 160.
[0037] The decomposition furnace 110 is used to calcine clay raw materials under an oxidizing atmosphere to achieve more complete and rapid calcination. The hot blast stove 120 is used to burn fuel to generate heat. The collecting cyclone 130 is used for solid-gas separation (separation of clay material and waste gas). The air-cooled rotary cooler 140 is used for non-contact air cooling of the clay material. The color reduction device 160 is used to reduce Fe2O3 in the clay material to Fe3O4.
[0038] Specifically, the vertical decomposition furnace 110 is used for calcining clay raw materials in an oxidizing atmosphere. The decomposition furnace 110 is a prior art device well known to those skilled in the art, and its structure will not be described here.
[0039] A hot blast furnace 120 is used to burn fuel, such as waste. The hot blast furnace 120 is connected to the air inlet at the bottom of the decomposition furnace 110 via a heating pipe 121 to provide heat for clay calcination in the decomposition furnace 110. It can be understood that the heat required for clay calcination in the decomposition furnace 110 can be provided entirely or partially by the hot blast furnace 120. For example, the decomposition furnace 110 itself can also be equipped with a supplementary fuel inlet 111 to inject fuel into the decomposition furnace 110 to provide heat and maintain the temperature inside the decomposition furnace 110. The temperature inside the decomposition furnace 110 is generally controlled between 700 and 900°C.
[0040] A collecting cyclone separator 130 is used to separate the high-temperature clay material and waste gas generated from the calcination of clay raw materials in the decomposition furnace 110. The separated high-temperature clay material is connected to the color reduction device 160 through the feed pipe 150. The separated waste gas can enter the multi-stage suspension preheating cyclone separator 170.
[0041] The multi-stage suspension preheating cyclone 170 is used to preheat the clay raw material to be calcined. The feed inlet of the lowest stage of the multi-stage suspension preheating cyclone 170 is connected to the decomposition furnace 110 via a feed pipe. The feed inlet of the lowest stage of the multi-stage suspension preheating cyclone 170 is connected to the air outlet of the collecting cyclone 130.
[0042] Multi-stage suspension preheating cyclone 170 is also a prior art device well known to those skilled in the art, and may include two to five stages of preheating cyclone 171 (the number of stages depends on the moisture content of the clay raw material). For example, clay raw material can be fed into the multi-stage suspension preheating cyclone 170 through a clay rotary feeder, and heated from top to bottom. The hot exhaust gas is cooled stage by stage, and the preheated high-temperature clay raw material finally enters the decomposition furnace 110 for calcination. In the decomposition furnace 110, the clay raw material undergoes dehydroxylation decomposition through high-temperature calcination. To ensure complete combustion of the fuel, the decomposition furnace 110 is in an oxidizing atmosphere, and impurities in the clay raw material, especially iron, are oxidized to Fe2O3 at high temperatures, turning reddish-brown.
[0043] The color reduction device 160, arranged in the feed pipe 150, includes a sealed housing 161 connected to the feed pipe 150. The housing 161 has an inlet at the bottom for introducing reducing gas and an outlet at the top for exhausting gas, used to reduce clay material falling from top to bottom within the housing 161. For example, the reducing gas can be carbon monoxide. High-temperature clay material can be evenly poured into the housing 161 of the color reduction device 160 from the top, and CO is introduced from the bottom of the housing 161, flowing upwards and out through the top. The clay material comes into full contact with the CO, reducing Fe2O3 in the clay material to Fe3O4, resulting in a grayish-black color, which then flows downwards into the air-cooled rotary cooler 140.
[0044] Furthermore, the gas flowing out from the top of the shell 161 may contain CO. Therefore, the outlet at the top of the shell 161 is also connected to the inlet of the decomposition furnace 110 via the circulation pipe 185 so that the gas can enter the decomposition furnace 110 for processing.
[0045] The air-cooled rotary cooler 140 includes a rotary cylinder 141 rotatable about a horizontal axis. Multiple cooling tubes (not shown) are arranged axially inside the rotary cylinder 141 and rotate with it. For example, the cooling tubes are arranged on the outer inner ring of the rotary cylinder 141. Cooling gas, such as cold air, is introduced into the cooling tubes to achieve non-contact heat exchange between the cooling gas and the high-temperature clay material. The inlet of the rotary cylinder 141 is connected via a feed pipe 150 to the housing 161 of the color restoration device 160, and then to the outlet of the collecting cyclone 130.
[0046] The calcined, high-temperature clay material enters the rotary cooler from the rear. As the cooler rotates, the clay material moves towards the front, exchanging heat with the cooling steel pipes. Cold air flows from the head of the cooler through internal steel pipes to the rear. The hot clay material and cold air exchange heat indirectly inside the cooler, cooling the clay to approximately 100°C while the air absorbs heat to 450°C. Since Fe3O4 oxidizes to Fe2O3 upon contact with oxygen above 300°C, the clay material is kept away from the cooling air and outside air within the cooler, ensuring that it is not oxidized during the cooling process.
[0047] To further improve the heat exchange effect between the high-temperature clay material and the cooling gas, preferably, the flow direction of the cooling gas in the cooling pipe is opposite to the movement direction of the clay material in the rotating drum 141. Figure 1 Taking the orientation shown as an example, the flow direction of the cooling air in the cooling pipe is from left to right. The movement direction of the clay material in the rotary drum 141 is from right to left.
[0048] Based on the above-described scheme, according to the control system 100 of this utility model embodiment, the clay raw material is fully calcined in the decomposition furnace 110 under an oxidizing atmosphere, and then separated by the collecting cyclone 130 and enters the color reduction device 160. The color reduction device 160 is filled with reducing gas from the bottom, and the rising reducing gas and the falling clay material are fully in contact in the color reduction device 160. The Fe2O3 in the clay material is reduced to Fe3O4, which turns gray-black. Then the clay material enters the air-cooled rotary cooler 140. In the air-cooled rotary cooler 140, the calcined clay material does not come into contact with the cooling gas and the outside air, ensuring that the clay material is not oxidized during the cooling process, thus realizing the color control of clay calcination.
[0049] Continue to refer to Figure 1In order to enable the clay raw materials to enter the decomposition furnace 110 for calcination in a more reasonable manner, the feed pipeline may also include a first branch pipe 181 and a second branch pipe 182.
[0050] One end of the first branch pipe 181 and the second branch pipe 182 are connected to the lower and middle parts of the decomposition furnace 110, respectively. The other ends of the first branch pipe 181 and the second branch pipe 182 are connected to the discharge port of the lowest stage cyclone of the multi-stage suspension preheating cyclone 170 via the material distribution valve 193. The material distribution valve 193 is used to reasonably distribute the proportion of clay raw materials entering the first branch pipe 181 and the second branch pipe 182 according to actual needs, so as to avoid the clay raw materials from concentrating.
[0051] In a preferred embodiment, a first airlock valve 191 may be provided at the inlet of the rotary drum 141. A second airlock valve 192 may be provided at the outlet of the rotary drum 141. This ensures that the rotary cooler itself is airtight and also prevents the clay material from being oxidized during the cooling process.
[0052] In the illustrated embodiment, the control system 100 according to the present invention may further include an exhaust gas pipeline 186 connected to the outlet of the uppermost cyclone of the multi-stage suspension preheating cyclone 170 for discharging exhaust gas.
[0053] The outlet of the cooling pipe can also be connected to the exhaust pipe 187 to discharge the cooled air after heat exchange. The exhaust pipe 187 can be connected to the third branch pipe 183 and the fourth branch pipe 184 respectively. The third branch pipe 183 can be connected to the waste gas pipe 186, which can be used to send the waste gas to the raw material drying system (existing equipment). The fourth branch pipe 184 can be connected to the hot air furnace 120 for heat recovery.
[0054] Furthermore, according to this control system 100, valves may be installed in the exhaust gas pipeline 186, the exhaust pipe 187, the third branch pipe 183, and the fourth branch pipe 184 for better gas transport or transfer. Fans may also be installed in the exhaust gas pipeline 186 and the exhaust pipe 187.
[0055] According to the control system 100 of this embodiment, the product color can be controlled during the production process, and the process flow can also be economically processed to ensure that CO emissions from waste gas do not exceed the standard. The entire control system has low pressure loss, high heat utilization rate, and recoverable heat, reducing system heat consumption. The calcined clay material produced can partially replace traditional cement clinker, achieving the goal of energy conservation and emission reduction.
[0056] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A clay calcination color control system characterized by, The control system comprises: a vertical decomposing furnace for calcining clay raw materials in an oxidizing atmosphere; a hot blast stove for burning fuel; wherein the hot blast stove is connected to an air inlet at the bottom of the decomposing furnace via a heat supply pipeline to provide clay calcination heat to the decomposing furnace; a collection cyclone for separating high-temperature clay materials and waste gas generated by the decomposing furnace calcining clay raw materials; an air-cooled rotary cooler comprising a rotary drum rotatable around a horizontal axis, a plurality of cooling pipes arranged inside the rotary drum and rotating with the rotary drum along the axial direction, and the cooling pipes being used for pouring cooling gas to achieve non-contact heat exchange between the cooling gas and the clay materials; wherein a feeding inlet of the rotary drum is connected to a discharging outlet of the collection cyclone via a feeding pipeline; and a color reduction device arranged in the feeding pipeline, comprising a closed shell connected to the feeding pipeline; the shell has an inlet at the bottom for pouring reducing gas and an outlet at the top for discharging exhaust gas, and is used for reducing reaction of clay materials falling from top to bottom in the shell.
2. The control system of claim 1, wherein, The control system further comprises a multi-stage suspension preheating cyclone for preheating clay raw materials to be calcined; wherein a discharging outlet of the lowermost stage cyclone of the multi-stage suspension preheating cyclone is connected to the decomposing furnace via a feeding pipeline, and a feeding inlet of the lowermost stage cyclone of the multi-stage suspension preheating cyclone is connected to an exhaust outlet of the collection cyclone.
3. The control system of claim 2, wherein, The feeding pipeline comprises a first branch and a second branch; wherein one end of the first branch and the second branch is connected to the lower part and the middle part of the decomposing furnace respectively, and the other end of the first branch and the second branch is connected to the discharging outlet of the lowermost stage cyclone of the multi-stage suspension preheating cyclone via a distribution valve.
4. The control system of claim 1, wherein, The outlet at the top of the shell is further connected to the air inlet of the decomposing furnace via a circulation pipeline; and / or The reducing gas is carbon monoxide.
5. The control system of claim 1, wherein, The flow direction of the cooling gas in the cooling pipe is opposite to the moving direction of the clay materials in the rotary drum.
6. The control system of claim 1, wherein, A first air lock valve is further arranged at the feeding inlet of the rotary drum; and / or A second air lock valve is further arranged at the discharging outlet of the rotary drum.
7. The control system of claim 1, wherein, The decomposing furnace is further provided with a supplementary fuel inlet.
8. The control system of claim 2, wherein, The control system further comprises at least the following pipelines: a waste gas pipeline connected to the exhaust outlet of the uppermost stage cyclone of the multi-stage suspension preheating cyclone for discharging waste gas; an exhaust gas pipeline connected to the exhaust outlet of the cooling pipe.
9. The control system of claim 8, wherein, The exhaust gas pipeline is connected to a third branch and a fourth branch respectively, the third branch is connected to the waste gas pipeline, and the fourth branch is connected to the hot blast stove.
10. The control system of claim 9, wherein, Valves are further arranged in at least one of the following pipelines: the waste gas pipeline; the exhaust gas pipeline; the third branch; the fourth branch; Fans are further arranged in at least one of the following pipelines: the waste gas pipeline; the exhaust gas pipeline.