A belt roasting machine

Abstract

The embodiment of the present application discloses a belt roasting machine, in which the exhaust gas generated in the soaking section and the post-roasting zone of the roasting section is supplied as reheated air to the preheating middle zone and preheating front zone of the preheating section, instead of introducing the exhaust gas in the post-roasting zone and the soaking section of the roasting section into the exhaust drying section in the prior art, thereby changing the flow direction of the reheated air and preventing the exhaust gas containing SO2 and NO from being introduced into the exhaust drying section. x The waste gas of corrosive gases such as argon is brought into the exhaust drying section, thereby reducing the risk of corrosion of the exhaust drying section and the pipelines connected to the exhaust drying section; since the hot air from the second cooling section is pure air, even if there is cross-wind between the exhaust drying section and the blast drying section, the gas entering the blast drying section from the exhaust drying section does not contain SO2 and NO x Corrosive gases such as argon and argon can be eliminated, thereby reducing the risk of corrosion of the blast drying section and the pipelines connected to the blast drying section, and preventing the exhaust gas discharged from the blast drying section from exceeding the standard.

Description

Technical Field

[0001] The present application relates to the technical field of pellet production, and in particular to a belt roaster. Background Art

[0002] The process air system of the belt roaster has seven process sections: blast drying section, exhaust drying section, preheating section, roasting section, soaking section, cooling section one, and cooling section two. The cooling fan blows ambient air into the cooling section one and two. After heat exchange with the pellets, the hot air generated in the cooling section two is fed to the blast drying section through the blast drying fan for preliminary drying of the green pellets. The exhaust gas from the blast drying section is discharged into the atmosphere after dust removal. The hot air generated in the cooling section one is fed to the soaking section, roasting section, and preheating section for preheating, roasting, and homogenization of the pellets. The hot exhaust gas from the soaking section and the post-roasting section is collected as reheated air and returned to the belt roaster system through the reheating fan. Most of it enters the exhaust drying section as a medium for exhaust drying, and the rest enters the preheating section as needed. The hot exhaust gas from the exhaust drying section, preheating section, and pre-roasting section is collected by the main exhaust fan and discharged into the atmosphere after dust removal, desulfurization, and denitrification.

[0003] In the existing belt roasting machine process air system, the hot air in the exhaust drying section mainly comes from the reheated air in the roasting section and the soaking section. Since the reheated air contains corrosive gases such as SO2 and NOx, the hot air entering the exhaust drying section is corrosive. The exhaust drying section and the pipes connected to the exhaust drying section need to be treated with anti-corrosion. In addition, there is a cross-wind phenomenon between the exhaust drying section and the blast drying section, which leads to corrosion of the blast drying section and the pipes connected to the blast drying section. The exhaust gas discharged from the blast drying section also contains SO2 and NOx, causing the exhaust gas emissions to exceed the standard.

[0004] Therefore, how to reduce the risk of corrosion of the exhaust drying section and the pipes connected to the exhaust drying section, as well as the blast drying section and the pipes connected to the blast drying section, while preventing the exhaust gas discharged from the blast drying section from exceeding the standard, has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0005] The present application proposes a belt roasting machine to reduce the risk of corrosion of the exhaust drying section and the pipeline connected to the exhaust drying section, as well as the blast drying section and the pipeline connected to the blast drying section, while preventing the exhaust gas discharged from the blast drying section from exceeding the standard.

[0006] In order to achieve the above-mentioned purpose, the present application provides a belt roasting machine, which includes a blast drying section, an exhaust drying section, a preheating section, a roasting section, a soaking section and a cooling section.

[0007] Along the moving direction of the material layer, the cooling section includes cooling section 1, cooling section 2 and cooling section 3.

[0008] The hot air generated in the cooling section is fed into the soaking section, the roasting section and the post-preheating zone of the preheating section.

[0009] The hot air generated by the second cooling section is fed into the preheating middle zone and preheating front zone of the preheating section and the exhaust drying section.

[0010] The hot air generated by the third cooling section is supplied to the blast drying section through the first pipeline.

[0011] The waste gas generated in the soaking section and the post-calcination zone of the calcination section is supplied as reheated air through the second pipeline into the preheating middle zone and preheating front zone of the preheating section.

[0012] Preferably, in the above-mentioned belt roasting machine, a part of the hot air generated by the cooling section is supplied to the equalizing section, and the other part of the hot air generated by the cooling section is fed into the secondary air main pipe 1, and the secondary air main pipe 1 is connected to the roasting section and the preheating post-zone of the preheating section through a short downcomer.

[0013] Preferably, in the above-mentioned belt roasting machine, the hot air generated by the second cooling section is merged into the secondary air main pipe 2, and the secondary air main pipe 2 is connected to the preheating middle zone and the preheating front zone of the preheating section through a first long downcomer, and the secondary air main pipe 2 is connected to the exhaust drying section through a second long downcomer.

[0014] Preferably, the above-mentioned belt roasting machine further includes a cooling air blower for supplying ambient air to the exhaust drying section.

[0015] Preferably, in the above-mentioned belt roaster, the second pipeline is connected to the preheating middle zone and the preheating front zone through the first long downcomer, and is used to supply reheated air to the preheating middle zone and the preheating front zone.

[0016] Preferably, in the above-mentioned belt roasting machine, the middle preheating zone is provided with a burner, and the front preheating zone is not provided with a burner.

[0017] Preferably, in the above-mentioned belt roasting machine, a first exhaust gas discharge pipeline is provided on the exhaust drying section, and a second exhaust gas discharge pipeline on the blast drying section is connected to the first exhaust gas discharge pipeline.

[0018] Preferably, in the above-mentioned belt roaster, a fan is provided on the first exhaust gas discharge pipe.

[0019] Preferably, the above-mentioned belt roasting machine further comprises a waste gas treatment pipeline connected to the preheating section and the pre-roasting zone of the roasting section, and the waste gas treatment pipeline can be connected to the waste gas treatment device.

[0020] In the belt roasting machine provided by the embodiment of the present application, the exhaust gas generated in the soaking section and the post-roasting zone of the roasting section is supplied as reheated air to the preheating middle zone and preheating front zone of the preheating section, instead of introducing the exhaust gas from the post-roasting zone and the soaking section of the roasting section into the exhaust drying section in the prior art, thereby changing the flow direction of the reheated air and preventing the exhaust gas containing SO2 and NO from being introduced into the exhaust drying section. x The waste gas of corrosive gases such as argon is brought into the exhaust drying section, thereby reducing the risk of corrosion of the exhaust drying section and the pipelines connected to the exhaust drying section; since the hot air from the second cooling section is pure air, even if there is cross-wind between the exhaust drying section and the blast drying section, the gas entering the blast drying section from the exhaust drying section does not contain SO2 and NO x Corrosive gases such as argon and argon can be eliminated, thereby reducing the risk of corrosion of the blast drying section and the pipelines connected to the blast drying section, and preventing the exhaust gas discharged from the blast drying section from exceeding the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or prior art descriptions. Obviously, the drawings described below are only some examples or embodiments of the present application. For those of ordinary skill in the art, without paying any creative work, other drawings can be obtained based on the provided drawings, and the present application can also be applied to other similar scenarios based on the provided drawings. Unless it is obvious from the language context or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0022] Figure 1 It is a structural schematic diagram of the belt roasting machine of the present application.

[0023] in:

[0024] 1. Blast drying section, 2. Exhaust drying section, 3. Preheating section, 4. Roasting section, 5. Soaking section, 6. Cooling section, 61. Cooling section one, 62. Cooling section two, 63. Cooling section three, 7. Secondary air main pipe one, 8. Short downcomer, 9. Secondary air main pipe two, 10. First long downcomer, 11. Second long downcomer, 12. Second pipeline, 13. First exhaust gas discharge pipeline, 14. Second exhaust gas discharge pipeline, 15. Exhaust gas treatment pipeline. DETAILED DESCRIPTION

[0025] The present application will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are merely for explaining the related application and are not intended to limit the application. The described embodiments are merely a portion of the embodiments of the present application and are not intended to be exhaustive. All other embodiments derived by persons of ordinary skill in the art based on the embodiments in the present application without creative effort are intended to fall within the scope of protection of the present application.

[0026] It should be noted that, for ease of description, only the parts related to the relevant applications are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0027] It should be understood that the terms "system," "device," "unit," and / or "module" used in this application are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0028] As used in this application and the claims, unless the context clearly indicates an exception, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular and may include the plural, unless the context clearly indicates otherwise. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements. The phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, product, or apparatus that includes the elements.

[0029] In the description of the embodiments of this application, unless otherwise specified, " / " represents or. For example, A / B can represent A or B. "And / or" in this article is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of this application, "plurality" means two or more than two.

[0030] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0031] Flowcharts are used in this application to illustrate the operations performed by the systems according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0032] Pellet production mainly relies on high-temperature exhaust gas to roast green balls. The high-temperature exhaust gas is generated by the combustion process of roasting section 4. Roasting section 4 is equipped with a combustion chamber, which requires a certain amount of combustion-supporting air to mix and assist combustion. The heating temperature of roasting section 4 is above 1200℃.

[0033] See also Figure 1 Some embodiments of the present application disclose a belt roasting machine, including a forced air drying section 1, an exhaust air drying section 2, a preheating section 3, a roasting section 4, a soaking section 5 and a cooling section 6.

[0034] Along the moving direction of the material layer, the preheating section 3 is divided into the preheating front zone, the preheating middle zone and the preheating back zone;

[0035] Along the direction of material bed movement, the roasting section 4 is divided into a roasting front zone and a roasting rear zone, and the temperature of the roasting front zone is lower than that of the roasting rear zone;

[0036] Along the moving direction of the material layer, the cooling section 6 includes a cooling section 1 61 , a cooling section 2 62 and a cooling section 3 63 . Partition walls are provided between the cooling section 1 61 and the cooling section 2 62 , and between the cooling section 2 62 and the cooling section 3 63 . The cooling section 1 61 is connected to the heat-saturating section 5 .

[0037] The cooling fan blows ambient air into the first cooling section 61, the second cooling section 62 and the third cooling section 63, and the temperatures of the first cooling section 61, the second cooling section 62 and the third cooling section 63 decrease in sequence.

[0038] like Figure 1 As shown, in this application, the hot air generated by the cooling section 61 is fed into the equalizing section 5, the roasting section 4 and the preheating rear zone of the preheating section 3. The temperature of the cooling section 61 of the cooling section 6 is the highest. The hot air of the cooling section 61 flows to the equalizing section 5, the roasting section 4 and the preheating section 3 to equalize, roast and preheat the pellets respectively; the hot air generated by the cooling section 2 62 is fed into the preheating middle zone, the preheating front zone and the exhaust drying section 2 of the preheating section 3; the hot air generated by the cooling section 3 63 is fed into the blast drying section 1 through the first pipeline, and the hot air of the cooling section 3 63 is used for the preliminary drying of the pellets.

[0039] The temperatures in the front, middle, and rear preheating zones gradually increase. The heat in the preheating zone primarily comes from fuel combustion. The hot air from the first cooling stage 61 is hotter than the second cooling stage 62. The first cooling stage 61 provides supplemental heat to the rear preheating zone, which has a higher temperature requirement, while the hot air from the second cooling stage 62 provides supplemental heat to the middle and front preheating zones, which have lower temperature requirements. Supplemental heat to the preheating zone from the hot air from the first and second cooling stages 61 and 62 reduces fuel consumption in the preheating zone.

[0040] The hot air required by the exhaust drying section 2 is lower than that required by the preheating zone. In this application, the lower-temperature hot air from the exhaust drying section 2, the preheating front zone, and the mid-preheating zone is supplemented with heat from the lower-temperature hot air from the cooling section 2 62, thus reducing heat waste. If the hot air temperature supplied by the cooling section 2 62 exceeds the required hot air temperature for the exhaust drying section 2, the hot air is cooled by the cooling air blower.

[0041] In the present application, in addition to the burner combustion heat supplementation, the hot air from the cooling section 61 can also be used to supplement heat to the roasting section 4, thereby reducing energy consumption.

[0042] The hot air from the cooling section 1 61 and the cooling section 2 62 can not only supplement the heat for the roasting section 4 and the preheating section 3, but also when the oxygen content of the belt roaster is low, the high-temperature heat-recovered exhaust gas from the cooling section 1 61 and the cooling section 2 62 can be used as combustion-supporting air, ensuring that the roasting section 4 and the preheating middle zone and preheating front zone of the preheating section 3 can reach the required temperature under conditions of low calorific value.

[0043] The belt roasting disclosed in the present application utilizes the reheated air of different temperatures generated by the belt roasting machine to make fine use of the hot air generated by the cooling section 6, so as to better complete the pellet roasting process and reduce energy consumption.

[0044] The heat of the exhaust drying section 2 comes from the cooling section 2 62. The hot air of the cooling section 2 62 is ambient air and does not contain corrosive gases such as SO2 and NOx. Therefore, the exhaust drying section 2 and the pipeline connected to the exhaust drying section 2 do not need to be treated with anti-corrosion, which reduces costs.

[0045] The exhaust gas generated in the soaking section 5 and the post-calcination zone of the calcination section 4 is supplied as reheated air to the middle preheating zone and the front preheating zone of the preheating section 3 through the second pipeline 12. Corrosive gases such as SO2 and NOx are generated in the preheating section 3, the calcination section 4, and the soaking section 5. That is, the exhaust gas generated in the soaking section 5 and the post-calcination zone of the calcination section 4 contains corrosive gases such as SO2 and NOx, and the exhaust gas generated in the middle preheating zone and the front preheating zone also contains corrosive gases such as SO2 and NOx. In other words, the exhaust gas containing corrosive gases such as SO2 and NOx will only circulate within the space where the exhaust gas is generated and will not enter other zones.

[0046] In the present application, an exhaust gas treatment pipeline 15 is provided in the preheating section 3 and the pre-calcination zone to treat dust and corrosive gases such as SO2 and NOx in the exhaust gas.

[0047] In the belt roasting machine disclosed in the present application, the exhaust gas generated in the soaking section 5 and the post-roasting zone of the roasting section 4 is supplied as reheated air to the preheating middle zone and preheating front zone of the preheating section 3, instead of introducing the exhaust gas from the post-roasting zone and the soaking section 5 of the roasting section 4 into the exhaust drying section 2 in the prior art, thus changing the flow direction of the reheated air and preventing the exhaust gas containing SO2 and NO from being introduced into the exhaust drying section 2. x The waste gas containing corrosive gases such as SO2 and NO2 is brought into the exhaust drying section 2, thereby reducing the risk of corrosion of the exhaust drying section 2 and the pipelines connected to the exhaust drying section 2; since the hot air from the cooling second section 62 is pure air, even if there is cross-flow between the exhaust drying section 2 and the blast drying section 1, the gas entering the blast drying section 1 from the exhaust drying section 2 does not contain SO2 and NO xCorrosive gases such as argon and argon can be removed, thereby reducing the risk of corrosion of the blast drying section 1 and the pipelines connected to the blast drying section 1, and preventing the exhaust gas discharged from the blast drying section 1 from exceeding the standard.

[0048] The hot air from the second cooling section 62 is introduced into the exhaust drying section 2. The hot air temperature of the second cooling section 62 is lower than the hot air temperature of the first cooling section 61 and higher than the hot air temperature of the third cooling section 63. This not only meets the heat demand of the exhaust drying section 2 for drying, but also reduces heat loss compared to the method of introducing the higher temperature reheated air into the exhaust drying section 2.

[0049] The hot air generated by the cooling section 61 is divided into two parts. One part is directly supplied to the soaking section 5, and the other part is collected in the secondary air main pipe 7. The secondary air main pipe is connected to the roasting section 4 and the post-preheating area of the preheating section 3 through a short downcomer 8. The hot air generated by the cooling section 61 is pure air.

[0050] The cooling section 61 is connected to the soaking section 5, and the hot air generated by the cooling section 61 can be directly supplied to the soaking section 5 through the connection position between the cooling section 61 and the soaking section 5. The hot air from the cooling section 61 is directly supplied to the soaking section 5, which can prevent the soaking section 5 from containing SO2 and NO. x The waste gas containing corrosive gases enters the cooling section 6, further reducing the risk of corrosion of the cooling section 6 and the exhaust drying section 2.

[0051] Short downcomers 8 are provided in the roasting section 4 and the post-preheating zone. Compared with the method of supplying air through a total air inlet, supplying air through several short downcomers 8 can solve the problem of uneven distribution of hot air in the roasting section 4 and the post-preheating zone, and control the temperature in the furnace within the set range.

[0052] The number of the short downcomers 8 provided in the roasting section 4 and the post-preheating zone is set by those skilled in the art according to temperature requirements.

[0053] The hot air generated by the second cooling section 62 flows into the secondary air main pipe 2 9, which is connected to the preheating middle and preheating front zones of the preheating section 3 via the first long downcomer 10. The secondary air main pipe 2 9 is connected to the exhaust drying section 2 via the second long downcomer 11. The hot air generated by the second cooling section 62 is also pure air.

[0054] A first downcomer is provided in the middle preheating zone and the front preheating zone, and a second long downcomer 11 is provided in the exhaust drying section 2. Compared with the method of supplying air through a total air inlet, supplying air through several long downcomers can solve the problem of uneven distribution of hot air and large eddy currents in the middle preheating zone, the front preheating zone and the exhaust drying section 2, and control the temperature in the furnace within the set range.

[0055] The number of first long downcomers 10 provided in the middle preheating zone and the front preheating zone, and the number of second long downcomers 11 provided in the exhaust drying section 2 are set by those skilled in the art according to temperature requirements.

[0056] The first long downcomer 10 and the second long downcomer 11 are symmetrically distributed on both sides of the secondary air main pipe in the longitudinal direction.

[0057] like Figure 1 As shown, the cooling fan is connected to the second long downcomer 11.

[0058] The cooling fan can also be directly connected to the air hood of the exhaust drying section 2.

[0059] When the air temperature of the exhaust drying section 2 exceeds the preset temperature, the amount of ambient air is increased; when the air temperature of the exhaust drying section 2 is lower than the preset temperature, the amount of ambient air is reduced.

[0060] like Figure 1 As shown, the second pipeline 12 is connected to the preheating middle zone and the preheating front zone through the second long downcomer 11, and is used to supply reheated air to the preheating middle zone and the preheating front zone.

[0061] The hot air in the middle preheating zone and the front preheating zone comes from two sources, one of which is the returned hot air from the second pipeline 12 , and the other is the hot air from the second cooling section 62 .

[0062] In this embodiment, the preheating front zone is not provided with a burner, but the preheating middle zone is provided with a burner. The burner is provided in the preheating middle zone to facilitate temperature control.

[0063] A first exhaust gas exhaust pipeline 13 is provided on the exhaust drying section 2, and a second exhaust gas exhaust pipeline 14 is provided on the blast drying section 1. The first exhaust gas exhaust pipeline 13 and the second exhaust gas exhaust pipeline 14 are connected to achieve mixing of the exhaust gas generated by the exhaust drying section 2 and the exhaust gas generated by the blast drying section 1.

[0064] The hot air in the blast drying section 1 flows from bottom to top. The pure hot air first enters the blast drying bellows, passes upward through the material layer to dry it, and then enters the upper hood of the blast drying section 1 as exhaust gas, which is then discharged directly through the first exhaust gas discharge pipe of the blast drying section 1. The hot air in the exhaust drying section 2 flows from top to bottom. The hot air first enters the exhaust hood, passes downward through the material layer to dry it, and then enters the exhaust bellows as exhaust gas. The hot air in the exhaust drying section 2 originates from the second cooling section 62. This pure hot air is free of SO₂ and NOx, and can therefore be mixed with the exhaust gas from the blast drying section 1 for dust removal. This is the exhaust gas treatment for all exhaust gases generated by the belt roaster. The exhaust gas does not contain corrosive gases such as SO₂ and NOx, which reduces the amount of waste gas required for desulfurization and denitrification treatment, thereby lowering production costs.

[0065] A fan is provided on the first exhaust gas discharge pipeline 13 of the exhaust drying section 2 to provide power for mixing the exhaust gas from the first exhaust gas discharge pipeline 13 with the exhaust gas from the second exhaust gas discharge pipeline 14 .

[0066] This solution designs the cooling section 6 as a three-stage cooling system based on the existing belt roaster. At the same time, taking into account the corrosion of the existing belt roaster's drying section pipelines, dust removal facilities and chimneys, and the large amount of waste gas and high cost of desulfurization and denitrification treatment, the pure air from the second cooling section 62 is introduced into the exhaust drying section 2 to reduce the amount of waste gas containing corrosive gases such as NOx and SO2, while avoiding the corrosion problem caused by the hot air from the furnace hood of the exhaust drying section 2 entering the furnace hood of the blast drying section 1.

[0067] The gas flowing into the second cooling section 62 comes from ambient air, not the waste gas from the preheating section 3 and the roasting section 4 after desulfurization and denitrification treatment.

[0068] The waste gas after desulfurization and denitrification treatment will be discharged into the atmosphere. The cooling section 6 is the main air inlet of the belt roaster, and clean air is supplied.

[0069] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used, and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. The scope of application involved in this application is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned application concept. For example, the above-mentioned features are replaced with (but not limited to) technical features with similar functions disclosed in this application to form a technical solution.

Claims

1. A belt roasting machine, characterized in that: It includes a blast drying section (1), an exhaust drying section (2), a preheating section (3), a roasting section (4), a soaking section (5) and a cooling section (6). Along the moving direction of the material layer, the cooling section (6) includes a first cooling section (61), a second cooling section (62) and a third cooling section (63). The hot air generated by the cooling section (61) is fed into the soaking section (5), the roasting section (4) and the preheating rear zone of the preheating section (3). The hot air generated by the second cooling section (62) is fed into the preheating middle zone and preheating front zone of the preheating section (3) and the exhaust drying section (2). The hot air of the second cooling section (62) is pure air and does not contain corrosive gases. The hot air generated by the third cooling section (63) is supplied to the blast drying section (1) through the first pipeline. The waste gas generated in the soaking section (5) and the post-calcination zone of the calcination section (4) is supplied as reheated air to the preheating middle zone and preheating front zone of the preheating section (3) through the second pipeline (12).

2. The belt roasting machine according to claim 1, characterized in that A portion of the hot air generated by the cooling section (61) is supplied to the equalizing section (5), and another portion of the hot air generated by the cooling section (61) is fed into the secondary air main pipe 1 (7). The secondary air main pipe 1 (7) is connected to the roasting section (4) and the preheating rear zone of the preheating section (3) through a short downcomer (8).

3. The belt roasting machine according to claim 1, characterized in that The hot air generated by the second cooling section (62) flows into the second secondary air main pipe (9), and the second secondary air main pipe (9) is connected to the preheating middle zone and the preheating front zone of the preheating section (3) through the first long downpipe (10), and the second secondary air main pipe (9) is connected to the exhaust drying section (2) through the second long downpipe (11).

4. The belt roasting machine according to claim 3, characterized in that It also includes a cooling fan for supplying ambient air to the exhaust drying section (2).

5. The belt roasting machine according to claim 4, characterized in that The second pipeline (12) is connected to the preheating middle zone and the preheating front zone through the first long downcomer (10) and is used to supply reheated air to the preheating middle zone and the preheating front zone.

6. The belt roasting machine according to claim 5, characterized in that The middle preheating zone is provided with a burner, while the front preheating zone is not provided with a burner.

7. The belt roasting machine according to claim 1, characterized in that The exhaust drying section (2) is provided with a first waste gas discharge pipeline (13), and the second waste gas discharge pipeline (14) on the blast drying section (1) is connected to the first waste gas discharge pipeline (13).

8. The belt roasting machine according to claim 7, characterized in that The first exhaust gas discharge pipe is provided with a fan.

9. The belt roaster according to claim 1, characterized in that It also includes a waste gas treatment pipeline (15) which is in communication with the preheating section (3) and the pre-calcination zone of the calcination section (4); the waste gas treatment pipeline (15) can be in communication with a waste gas treatment device.

Images