Hot air roasting furnace

Abstract

The utility model relates to the technical field of calcining furnaces, in particular to a hot air roasting furnace. The hot air roasting furnace comprises an outer layer furnace body; a hearth is formed on the inner side of the inner-layer furnace cover, and the bottom wall of the inner-layer furnace cover is a pore plate; the side air inlet interlayer is formed between the side wall of the inner-layer furnace cover and the outer-layer furnace body on the side surface; the bottom air inlet interlayer is formed between the bottom wall of the inner-layer furnace cover and the outer-layer furnace body at the lower part; the air inlet hole is formed in the upper part of the side ventilation interlayer and penetrates through the top wall of the outer-layer furnace body; and the air outlet hole is formed in the upper part of the hearth and penetrates through the top wall of the outer-layer furnace body. According to the utility model, the air inlet holes are directly formed in the outer layer furnace body above the left / right air inlet interlayer, so that the air steering resistance is reduced, and the air inlet efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of calcining furnace technology, and in particular to a hot air calcining furnace. Background Technology

[0002] Honeycomb catalysts are widely used in flue gas treatment due to their low resistance drop. However, compared to granular catalysts, their smaller outer surface area results in lower overall activity. To overcome this problem, the number of pores and the length of the honeycomb catalyst are typically increased. If a conventional mesh belt kiln is used for calcination, the increased number and length prevent hot air from entering the pores during calcination, leading to insufficient oxygen contact and incomplete calcination, especially in the central part of the catalyst. While a horizontal hot air calciner can achieve thorough calcination, it results in lower yield and greater heat loss. Utility Model Content

[0003] I. Technical problems to be solved

[0004] This invention aims to solve at least partially one of the aforementioned technical problems.

[0005] II. Technical Solution

[0006] The first aspect of this utility model provides a hot air roasting furnace. The hot air roasting furnace includes: an outer furnace body; an inner furnace hood, the inner side of which forms a furnace chamber, and its bottom wall is a perforated plate; a side air inlet jacket formed between the side wall of the inner furnace hood and the outer furnace body on the side; a bottom air inlet jacket formed between the bottom wall of the inner furnace hood and the lower part of the outer furnace body; an air inlet hole disposed in the upper part of the side air inlet jacket, penetrating the top wall of the outer furnace body; and an air outlet hole disposed in the upper part of the furnace chamber, penetrating the top wall of the outer furnace body.

[0007] In some embodiments of this utility model, it further includes: S heating tubes, inserted into the side air intake jacket along the depth direction of the furnace, where S≥2.

[0008] In some embodiments of this utility model, it further includes: a blower, disposed on the outside of the outer furnace body; an air inlet pipe extending from the air inlet of the blower to the air inlet hole; an air outlet pipe extending from the air outlet hole to the outside of the furnace chamber; and an induced draft fan, the air outlet of which is connected to the air outlet pipe.

[0009] In some embodiments of this utility model, an air inlet valve is provided on the outside of the air inlet of the blower; an air outlet valve is provided on the outside of the air outlet of the induced draft fan; and it also includes: a cross-line valve, the first end of which is connected to the air inlet of the blower, and the second end of which is connected to the air outlet of the induced draft fan.

[0010] In some embodiments of this utility model, the side air inlet jacket includes a left air inlet jacket and a right air inlet jacket, which are symmetrically formed on the left and right sides of the inner furnace hood; the air inlet holes include N left air inlets and N right air inlets arranged along the depth direction of the furnace, which are respectively arranged on the upper part of the left air inlet jacket and the right air inlet jacket, where N≥2.

[0011] In some embodiments of this utility model, the air inlet duct includes: N left air inlet pipes, each inserted into a corresponding left air inlet hole; N right air inlet pipes, each inserted into a corresponding right air inlet hole; and a main air inlet pipe, the left and right branches of which are connected to the N left air inlet pipes and the N right air inlet pipes respectively, with the central main pipe connected to the air inlet of the blower.

[0012] In some embodiments of this utility model, the air outlet includes: M left air outlets and M right air outlets arranged along the depth direction of the furnace, respectively located on the left and right sides of the upper part of the furnace, where M≥2; the air outlet pipeline includes: M left air outlet pipes, each inserted into the corresponding left air outlet; M right air outlet pipes, each inserted into the corresponding right air outlet; and a main air outlet pipe, the left and right branches of which are connected to the M left air outlet pipes and the M right air outlet pipes, respectively, with the central main pipe connected to the air inlet of the induced draft fan.

[0013] In some embodiments of this utility model, the projection of the air outlet main pipe on the horizontal plane is located inside the projection of the air inlet main pipe on the horizontal plane.

[0014] In some embodiments of this utility model, the air inlet main pipe is a gate-shaped air inlet main pipe; the air outlet main pipe is an I-shaped air outlet main pipe; the height of the air inlet main pipe is greater than the height of the air outlet main pipe; the middle main pipe of the I-shaped air outlet main pipe passes through the connection between the air supply fan and the induced draft fan; the cross-line valve is located above the middle main pipe of the I-shaped air outlet main pipe.

[0015] In some embodiments of this utility model, the outer furnace body is paved with refractory bricks; and / or, the inner furnace hood is made of steel.

[0016] III. Beneficial Effects

[0017] As can be seen from the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0018] (1) In this utility model, the air inlet is provided above the left and right air inlet jackets, penetrating the top wall of the outer furnace body, rather than in the square shape of the furnace chamber. The reason is:

[0019] ① Better air intake efficiency

[0020] Air inlets are directly installed on the outer furnace body above the left / right air inlet jacket, reducing air turning resistance and improving air intake efficiency.

[0021] ② Better reliability

[0022] This avoids the need for a top-inlet air jacket above the furnace, greatly simplifying the furnace structure and improving mechanical strength and reliability.

[0023] ③ Make full use of the space at the top of the furnace body, and the pipeline layout is more reasonable.

[0024] An air inlet is installed above the left / right air inlet jacket, i.e., on the outer top; and an air outlet is installed above the furnace chamber, i.e., on the inner top. This makes full use of the space at the top of the furnace body and is beneficial for the subsequent arrangement of air inlet / outlet pipes.

[0025] (2) In this utility model, side air intake jackets are provided on both the left and right sides of the furnace, which improves the air intake efficiency and enhances the uniformity of temperature in the furnace.

[0026] (3) In this utility model, by adjusting the cross-line valve between the feed fan and the induced draft fan, as well as the air volume of the feed fan and the induced draft fan, the self-circulation of hot air inside the furnace or the complete / partial external exchange can be achieved. Taking honeycomb catalyst as an example, the catalyst roasting process can be divided into a heating stage and a constant temperature roasting stage. During the heating stage, the catalyst does not react with oxygen before reaching the specified temperature. At this time, the cross-line valve can be opened, and the air inlet valve and air outlet valve can be closed to allow the air to circulate in the furnace chamber and between the heating jackets of the roasting furnace, thereby reducing heat loss and making the temperature uniform. When the temperature at which the catalyst reacts with oxygen is reached, the cross-line valve can be closed or partially closed, and the air inlet valve and air outlet valve can be opened to allow fresh air containing sufficient oxygen to enter, so as to ensure that there is sufficient oxygen in the roasting atmosphere.

[0027] (4) In this utility model, the main air inlet pipe is a gate-shaped main air inlet pipe; the main air outlet pipe is an I-shaped main air outlet pipe; the height of the main air inlet pipe is greater than the height of the main air outlet pipe; the projection of the main air outlet pipe on the horizontal plane is located inside the horizontal projection of the main air inlet pipe. The middle section of the main air outlet pipe passes through the line connecting the feed fan and the induced draft fan; the cross-line valve is located above the middle section of the I-shaped main air outlet pipe. By setting it up in this way, the use of complex and high-cost piping components is avoided, and the horizontal and vertical space above the furnace body is fully utilized, resulting in a reasonable layout and convenient control.

[0028] (5) When calcining the honeycomb catalyst, the honeycomb catalyst channels are placed vertically in the hot air calciner. Hot air passes through each channel of the honeycomb catalyst from bottom to top, making full contact with the catalyst and providing heat and oxygen to the catalyst.

[0029] It is evident that the hot air calciner of this invention can overcome the problem of incomplete calcination of the honeycomb catalyst center in mesh belt kiln calcination, and can also effectively reduce heat loss. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the hot air roasting furnace according to an embodiment of the present invention.

[0031] Figure 2 for Figure 1 The diagram shows a portion of the hot air roasting furnace body.

[0032] Figure 3 for Figure 2 The diagram shows the hot air flow direction of the furnace body.

[0033] Figure 4 for Figure 1 The image shows a top view of the hot air roasting furnace. Detailed Implementation

[0034] The purpose of this invention is to provide a roasting furnace with smooth air intake, high thermal efficiency, and convenient and flexible operation. This roasting furnace can be used not only for the preparation of honeycomb catalysts, but also for other hot air roasting applications.

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with specific embodiments and with reference to the accompanying drawings.

[0036] Figure 1 This is a schematic diagram of the hot air roasting furnace according to an embodiment of the present invention. Figure 2 for Figure 1 The diagram shows a portion of the hot air roasting furnace body. Figure 3 for Figure 2 The diagram shows the hot air flow direction of the furnace body. Figure 4 for Figure 1 The image shows a top view of the hot air roasting furnace. To facilitate observation of the internal structure, [the image is shown in the image]. Figure 1 , Figure 2 , Figure 3 In the middle section, the front furnace door of the furnace body is omitted. Figure 3 In the image, the arrow indicates the direction of the hot air flow. The following is combined with... Figures 1-4 The specific structure of the hot air roasting furnace in this embodiment will be described in detail.

[0037] like Figures 1-3 As shown, the hot air roasting furnace in this embodiment includes a furnace body and a piping system. The furnace body can be manufactured, sold, and used separately. The piping system is used in conjunction with the furnace body.

[0038] like Figures 1-3 As shown, in this embodiment, the furnace body has an overall box-like structure, including:

[0039] Outer furnace body 10;

[0040] The inner furnace hood 20 forms a furnace chamber on its inner side, and its bottom wall is a perforated plate 21;

[0041] The left air inlet jacket 31 and the right air inlet jacket 32 ​​are formed between the side wall of the inner furnace hood and the outer furnace body on the side. They are equipped with heating pipes 34 along the depth of the furnace chamber for heating fresh air.

[0042] Bottom air inlet jacket 33 is formed between the bottom wall of the inner furnace hood and the lower outer furnace body;

[0043] Air inlet 11 is located at the upper part of the side ventilation jacket and penetrates the top wall of the outer furnace body;

[0044] Air outlet 12 is located at the upper part of the furnace chamber and penetrates the top wall of the outer furnace body.

[0045] It is particularly important to emphasize that in this embodiment, the air inlet is located above the left and right air inlet jackets, penetrating the top wall of the outer furnace body, rather than squarely within the furnace chamber. The reason for this is:

[0046] ① Better air intake efficiency

[0047] Air inlet holes are set on the outer furnace body above the left / right air inlet jacket, which reduces air turning resistance and improves air intake efficiency.

[0048] ② Better reliability

[0049] This avoids the need for a top-inlet air jacket above the furnace, greatly simplifying the furnace structure and improving mechanical strength and reliability.

[0050] ③ Make full use of the space at the top of the furnace body, and the pipeline layout is more reasonable.

[0051] An air inlet is provided above the left / right air inlet jacket, i.e., on the outer top; and an air outlet is provided above the furnace chamber, i.e., on the inner top. This makes full use of the space at the top of the furnace body and is beneficial for the subsequent arrangement of air inlet / outlet pipes, which will be explained in detail in the subsequent pipe section.

[0052] In this embodiment, the outer furnace body 10 is surrounded by refractory bricks to minimize heat loss. The inner furnace hood 20 is a steel structure. In particular, the bottom wall of the inner furnace hood is a perforated plate 21. In this case, hot air can pass through the perforated plate and roast the material in the furnace from top to bottom.

[0053] like Figures 1-3 As shown, in this embodiment, the side air inlet jacket includes a left air inlet jacket 31 and a right air inlet jacket 32, which are symmetrically formed on the left and right sides of the inner furnace hood. Correspondingly, the air inlet holes include N left air inlets and N right air inlets, which are respectively provided on the upper part of the left air inlet jacket and the right air inlet jacket. The N left air inlets and N right air inlets are all arranged along the depth direction of the furnace, and N≥2.

[0054] In this embodiment, side air intake jackets are provided on both the left and right sides of the furnace, which improves air intake efficiency and enhances temperature uniformity within the furnace. However, those skilled in the art should understand that providing a side air intake jacket on only one side of the furnace can also achieve the present invention and is within the scope of protection of this invention.

[0055] In this embodiment, five air inlets 11 penetrating the top wall of the outer furnace body are provided above the left and right air inlets; two × two air outlets 12 penetrating the top wall of the outer furnace body are provided above the furnace chamber; and ten heating tubes are provided in each of the left and right air inlets, but this utility model is not limited thereto. In other embodiments of this utility model, the number of air inlets, air outlets, and heating tubes can be reasonably set according to the furnace body size, pipe diameter, roasting requirements, etc. For example, if the left / right air inlets are thick enough, two rows of air inlets and two rows of heating tubes can be provided. These variations can also realize this utility model and are also within the protection scope of this utility model.

[0056] like Figure 1 , Figure 4 As shown, the piping section of the hot air roasting furnace in this embodiment includes: an air inlet pipe extending from the air inlet hole to the outside of the furnace chamber; a blower 41, whose air inlet is connected to the air inlet pipe; an air outlet pipe extending from the air outlet hole to the outside of the furnace chamber; and an induced draft fan 51, whose induced draft port is connected to the air outlet pipe.

[0057] It should be particularly emphasized that, in this embodiment, an air inlet valve 42 is provided on the outside of the air inlet of the blower; an air outlet valve 52 is provided on the outside of the air outlet of the induced draft fan; and a cross-line valve 61 is connected at its first end to the air inlet of the blower and at its second end to the air outlet of the induced draft fan.

[0058] In existing technologies, the air inside the furnace does not exchange with the outside, but only circulates within the furnace body and the furnace jacket (heating flue). For roasting reactions involving oxygen, the oxygen in the atmosphere inside the furnace will gradually be consumed, resulting in incomplete roasting, which may affect the roasting effect, especially for honeycomb catalysts.

[0059] In this embodiment, by adjusting the cross-line valve between the feed fan and the induced draft fan, as well as the air volume of the feed fan and the induced draft fan, the self-circulation of hot air inside the furnace or complete / partial external exchange can be achieved. Taking a honeycomb catalyst as an example, the catalyst roasting process can be divided into a heating stage and a constant-temperature roasting stage. During the heating stage, the catalyst does not react with oxygen before reaching the specified temperature. At this time, the cross-line valve can be opened, and the inlet and outlet valves can be closed, allowing the air to circulate in the furnace chamber and between the heating jackets of the roasting furnace, reducing heat loss and making the temperature uniform. When the temperature for the catalyst to react with oxygen is reached, the cross-line valve can be closed or partially closed, and the inlet and outlet valves can be opened to allow fresh air containing sufficient oxygen to enter, so as to ensure that there is sufficient oxygen in the roasting atmosphere.

[0060] Please continue to refer to Figure 1 , Figure 4 The air inlet duct includes: 5 left air inlet pipes 43, which are inserted into the corresponding left air inlet holes respectively; 5 right air inlet pipes 44, which are inserted into the corresponding right air inlet holes respectively; and a main air inlet pipe 45, whose left and right branches are connected to the 5 left air inlet pipes and the 5 right air inlet pipes respectively, and the central main pipe is connected to the air inlet of the blower.

[0061] Please continue to refer to Figure 1 , Figure 4 The air outlets include two left air outlets and two right air outlets, which are respectively located on the left and right sides of the upper part of the furnace. Both the two left and two right air outlets are arranged along the depth of the furnace. The air outlet ducts include two left air outlet pipes 53, each inserted into a corresponding left air outlet; two right air outlet pipes 54, each inserted into a corresponding right air outlet; and a main air outlet pipe 55, whose left and right branches are connected to the two left air outlet pipes and the two right air outlet pipes respectively, with the central main pipe connected to the induced draft fan's air inlet.

[0062] In this embodiment, the main air inlet pipe 45 is a gate-shaped main air inlet pipe; the main air outlet pipe 55 is an I-shaped main air outlet pipe; the height of the main air inlet pipe 45 is greater than the height of the main air outlet pipe 55; the projection of the main air outlet pipe 55 on the horizontal plane is located inside the horizontal projection of the main air inlet pipe 45. The middle section of the main air outlet pipe 55 passes through the line connecting the feed fan 41 and the induced draft fan 51; the cross-line valve 61 is located above the middle section of the I-shaped main air outlet pipe. This arrangement avoids the use of complex and costly piping components, fully utilizes the horizontal and vertical space above the furnace body, and results in a reasonable layout and convenient control.

[0063] Please refer to Figure 3 The following details the working process of the hot air roasting furnace in this embodiment:

[0064] (1) Air intake

[0065] Fresh air enters the left / right air intake jackets on both sides through the air intake holes on both sides of the top by the blower. Electric heating tubes are placed in the left / right air intake jackets. The fresh air is heated to the required temperature by passing through the electric heating tubes from top to bottom to form hot air, which enters the interior of the roasting furnace box through the bottom perforated plate of the inner furnace cover.

[0066] (2) Calcination

[0067] Hot air comes into contact with the catalyst inside, calcining the catalyst under aerobic conditions.

[0068] Inside the hot air roasting furnace, the honeycomb catalyst channels are placed vertically, and hot air flows from bottom to top through each channel, ensuring full contact with the catalyst and providing it with heat and oxygen. This structure overcomes the problem of incomplete central roasting of honeycomb catalysts in mesh belt kilns and effectively reduces heat loss.

[0069] (3) Ventilation

[0070] After roasting, the air passes through the central sealing hole at the top of the roasting furnace and is discharged by the induced draft fan.

[0071] If a circulating air supply mode is used, the cross-line valve is opened, and the air inlet valve and air outlet valve are closed, allowing the air to circulate in the furnace chamber and heating jacket of the roasting furnace, reducing heat loss and making the temperature uniform.

[0072] If the fresh air mode is used, the cross-line valve can be closed or partially closed, and the air inlet valve and air outlet valve can be opened to allow fresh air containing sufficient oxygen to enter. After the fresh air is heated, the catalyst is roasted.

[0073] This concludes the description of all embodiments of this utility model. Based on the above description, those skilled in the art should have a clear understanding of this utility model.

[0074] It should also be noted that the directional terms mentioned in the embodiments, such as "center," "lateral," "longitudinal," "top," "bottom," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship only based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. Also, the shapes and dimensions of the components in the drawings do not reflect actual size and proportion, but only illustrate the content of the embodiments of the present invention.

[0075] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0076] Those skilled in the art will understand that in the claims and description of this utility model, the word "comprising" does not exclude the presence of elements (or steps) not listed in the claims. The word "a" or "an" preceding an element (or step) does not exclude the presence of a plurality of such elements (or steps).

[0077] For certain implementation methods, if they are not key contents of this utility model and are well known to those skilled in the art, they are not described in detail in the accompanying drawings or text due to space limitations. In such cases, they can be understood by referring to relevant prior art.

[0078] Furthermore, the purpose of providing the above embodiments is merely to enable the present invention to meet legal requirements, and the present invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0079] Similarly, it should be understood that, for the sake of brevity, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this approach should not be construed as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the claims, each aspect of the invention comprises fewer than all the features of the preceding single embodiment. Furthermore, embodiments may be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the present invention.

[0080] The above specific embodiments have provided a detailed description of the purpose, technical means, and beneficial effects of this utility model. It should be understood that the purpose of the detailed description is to enable those skilled in the art to understand this utility model more clearly, and it is not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A hot-air calcining furnace, characterized by comprising: Comprise: The outer layer furnace body; The inner layer furnace cover, the inner side of which forms the hearth, and the bottom wall of which is a hole plate; The side air inlet interlayer formed between the side wall and the side of the outer layer furnace body of the inner layer furnace cover; The bottom air inlet interlayer formed between the bottom wall and the lower part of the outer layer furnace body of the inner layer furnace cover; The air inlet hole provided in the upper part of the side air inlet interlayer and penetrating through the top wall of the outer layer furnace body; The air outlet hole provided in the upper part of the hearth and penetrating through the top wall of the outer layer furnace body.

2. The through-air dryer according to claim 1, wherein Further comprise: S heating pipes inserted into the side air inlet interlayer along the depth direction of the hearth, S≥2.

3. The through-air dryer of claim 1, wherein Further comprise: The air feeder provided outside the outer layer furnace body; The air inlet pipeline extending from the air inlet of the air feeder to the air inlet hole; The air outlet pipeline extending from the air outlet hole to the outside of the hearth; The air induction machine, the air induction port of which is connected to the air outlet pipeline.

4. The hot air roasting furnace according to claim 3, wherein, The air inlet of the air feeder is provided with an air inlet valve outside; The air outlet of the air induction machine is provided with an air outlet valve outside; Further comprise: the cross-line valve, the first end of which is connected to the air inlet of the air feeder, and the second end of which is connected to the air outlet of the air induction machine.

5. The hot air roasting furnace according to claim 4, wherein, The side air inlet interlayer comprises: left and right air inlet interlayers, which are symmetrically formed on the left and right sides of the inner layer furnace cover; The air inlet hole comprises: N left air inlet holes and N right air inlet holes arranged along the depth direction of the hearth, which are respectively arranged in the upper part of the left and right air inlet interlayers, N≥2.

6. The hot air roasting furnace according to claim 5, wherein, The air inlet pipeline comprises: N left air inlet exhaust pipes respectively inserted into the corresponding left air inlet holes; N right air inlet exhaust pipes respectively inserted into the corresponding right air inlet holes; The air inlet main pipe, the left and right branch pipes of which are respectively connected to the N left air inlet exhaust pipes and the N right air inlet exhaust pipes, and the middle main pipe of which is connected to the air inlet of the air feeder.

7. The hot air roasting furnace according to claim 6, wherein, The air outlet hole comprises: M left air outlet holes and M right air outlet holes arranged along the depth direction of the hearth, which are respectively arranged on the left and right sides of the upper part of the hearth, M≥2; The air outlet pipeline comprises: M left air outlet exhaust pipes respectively inserted into the corresponding left air outlet holes; M right air outlet exhaust pipes respectively inserted into the corresponding right air outlet holes; The air outlet main pipe, the left and right branch pipes of which are respectively connected to the M left air outlet exhaust pipes and the M right air outlet exhaust pipes, and the middle main pipe of which is connected to the air induction port of the air induction machine.

8. The hot air roasting furnace according to claim 7, wherein, The projection of the air outlet main pipe on the horizontal plane is located inside the horizontal plane projection of the air inlet main pipe.

9. The hot air roasting furnace according to claim 8, wherein, The air inlet main pipe is a door-shaped air inlet main pipe; The air outlet main pipe is a I-shaped air outlet main pipe; The height of the air inlet main pipe is greater than the height of the air outlet main pipe; The middle main pipe of the I-shaped air outlet main pipe passes through the position of the connecting line of the air feeder and the air induction machine; The cross-line valve is located in the upper part of the middle main pipe of the I-shaped air outlet main pipe.

10. The through-air dryer according to any one of claims 1 to 9, wherein the outer layer of the furnace body is paved with refractory bricks. and / or the inner layer of the furnace cover is made of a steel material. ​

Images