System comprising a rotatable hollow chamber and a heating system and method of heating a rotatable hollow chamber
By employing a countercurrent heating system in a rotary kiln reactor, the heating gas and cooling gas inside the muffle furnace are mixed, solving the problems of complex heating systems and low energy efficiency in existing technologies, and achieving the effects of simplifying the heating system and improving energy efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NESTE OYJ
- Filing Date
- 2024-09-18
- Publication Date
- 2026-06-12
AI Technical Summary
Existing rotary kiln reactors require separate heating of individual reactor areas to specific temperatures, resulting in complex heating systems and low energy efficiency.
A counter-current heating system is adopted, in which heating gas is introduced into the cavity of the muffle furnace and mixed with cooling gas near the rear end of the hollow chamber, reducing the number of heating zones and improving heat transfer efficiency by mixing the counter-current heating gas in the cavity.
This eliminates the need for separate heating of independent reactor areas, simplifies the heating system, improves energy efficiency, increases heat recovery, and reduces equipment complexity and cost.
Smart Images
Figure CN122206901A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a system comprising a rotatable hollow chamber and a heating system. In particular, this invention relates to a rotary kiln reactor.
[0002] Furthermore, the present invention relates to a method for heating a rotatable hollow chamber. Background Technology
[0003] Rotary kiln reactors are known for a variety of applications, such as the treatment of polymer waste materials. Polymers are used in a wide range of products. Polymers are typically obtained from petroleum resources, which are considered non-renewable. Therefore, a need has arisen for a sustainable supply of raw materials. Furthermore, the accumulation of polymer waste has been recognized as an environmental problem. Therefore, polymer waste is often collected and sorted for recycling or pyrolysis purposes. Environmental problems can be reduced through subsequent treatment of polymer waste materials and the reuse of at least a portion of the material as raw material for new products.
[0004] For example, polymer waste materials can be treated by pyrolysis, that is, by thermally decomposing the polymer waste materials at elevated temperatures in an inert atmosphere to obtain products containing gases from at least partially pyrolyzed polymer waste. This treatment can be carried out, for example, in a reactor, such as a rotary kiln reactor, into which the polymer waste is fed.
[0005] In existing rotary kiln reactors, a heating system including a muffle furnace is typically provided. High-temperature flue gas is introduced into the muffle furnace at multiple locations along its length, thereby individually heating distinct reactor zones to specific temperatures for the thermal decomposition of the material fed into the reactor through cross-flow. In other words, multiple cross-flow heating zones are provided, each with at least one dedicated heating gas inlet and at least one dedicated heating gas outlet.
[0006] In view of the above, it would be advantageous to provide a system capable of obtaining a gaseous product from at least partially pyrolyzed material and including a heating system, by which it is not necessary to individually heat separate reactor areas to a specific temperature. Summary of the Invention
[0007] This invention is defined by the features of the independent claims. Specific embodiments are defined in the dependent claims.
[0008] According to a first aspect of the invention, a system is provided, comprising: a rotatable hollow chamber having a front end and a rear end; a feeding system configured to feed material into the hollow chamber via at least one feed outlet; a gas outlet for collecting a product comprising gas from at least partially pyrolyzed material, wherein the system is configured to allow the gas from at least partially pyrolyzed material to flow in the rotatable hollow chamber in a direction substantially from the front end to the rear end; and a heating system comprising a muffle furnace that encloses at least a portion of the rotatable hollow chamber, thus ensuring that at least one of the outer surfaces of the rotatable hollow chamber... A cavity is provided between the portion and the wall of the muffle furnace, wherein a heating gas inlet for guiding heating gas into the cavity is located near the rear end of the rotatable hollow chamber, and a heating gas outlet for guiding heating gas out of the cavity is located near the front end of the rotatable hollow chamber, wherein the heating system further includes at least one first cooling gas inlet between the heating gas inlet and the heating gas outlet, the first cooling gas inlet for guiding cooling gas into the cavity to mix the cooling gas with the heating gas present in the cavity, and wherein the heating gas inlet includes an exhaust port capable of regulating, restricting or blocking the flow of heating gas into the cavity.
[0009] Various implementations of the first aspect may include at least one feature from the following bulleted list: The heating system is capable of heating the outer surface of the rotatable hollow chamber using heating gas present in the cavity. The system is configured such that the heated gas flow is guided through a cavity outside the rotatable hollow chamber in a direction substantially opposite to the direction of the gas flow from at least partially pyrolyzed material within the rotatable hollow chamber. The heating gas is different from the gas from the material that has undergone at least partial pyrolysis. The muffle furnace includes at least one protrusion that extends from the wall of the muffle furnace into the cavity and / or extends from the outer surface of the rotatable hollow chamber into the cavity. The at least one protrusion is disposed downstream of the heating gas inlet and downstream of at least one first cooling gas inlet. • Muffle furnaces are made of steel or refractory materials or a combination of both. The heating system includes a second cooling gas inlet connected to the heating gas inlet; According to a second aspect of the invention, a method for heating a rotatable hollow chamber is provided, the method comprising: providing a rotatable hollow chamber having a front end and a rear end; feeding material into the hollow chamber via at least one feed outlet of a feeding system; collecting a product comprising gas from at least partially pyrolyzed material through a gas outlet, wherein gas from at least partially pyrolyzed material is allowed to flow in the rotatable hollow chamber in a direction from the front end to the rear end; providing a muffle furnace that closes at least a portion of the rotatable hollow chamber, thus ensuring that at least a portion of the outer surface of the rotatable hollow chamber and the muffle furnace are closed. A cavity is provided between the walls of the furnace, into which heating gas is guided via a heating gas inlet located near the rear end of the rotatable hollow chamber, and out of the cavity via a heating gas outlet located near the front end of the rotatable hollow chamber. Cooling gas is guided into the cavity via at least one first cooling gas inlet and mixed with the heating gas, wherein at least one cooling gas inlet is arranged between the heating gas inlet and the heating gas outlet. An exhaust port is used to regulate, block, or restrict the flow of heating gas into the cavity.
[0010] Various implementations of the second aspect may include at least one feature from the following bulleted list: The method involves heating the outer surface of the rotatable hollow chamber with a heating gas present in the cavity. The method includes: guiding a heated gas flow from the outside of a rotatable hollow chamber in a direction substantially opposite to the direction of a gas flow from at least partially pyrolyzed material. The method includes increasing turbulence in the heated airflow by utilizing at least one protrusion protruding from the wall of the muffle furnace and / or from the outer surface into the cavity. The method includes mixing the cooling gas and the heating gas within the cavity. The cooling gas is air, recirculated heated gas, or recirculated flue gas with a lower temperature than the heated gas, CO2, nitrogen, or steam. Certain embodiments of the present invention offer considerable advantages. In particular, a system is provided capable of obtaining gaseous products from at least partially pyrolyzed materials and includes a heating system by means of which separate reactor zones do not need to be individually heated to specific temperatures. In other words, the heating system eliminates cross-flow heat transfer due to the countercurrent flow of the heating gas within the cavity. The heating gas is introduced into the muffle furnace cavity near the rear end of the rotatable hollow chamber, and therefore the maximum temperature difference from the heating gas to the process flow within the kiln is at the rear end of the reactor. Furthermore, the system's energy efficiency can be improved due to the increase in the total flow rate of the heating gas, resulting in increased turbulence and heat transfer efficiency for similar muffle furnace cavity geometries. Moreover, the improved energy efficiency is achieved by the countercurrent arrangement because more heat can be recovered from the heating gas than in a cross-flow arrangement, since the heating gas outlet temperature can be lower to achieve the same kiln interior temperature.
[0011] According to certain embodiments of the invention, high-temperature flue gas is introduced into the muffle furnace only near the rear end of the rotatable hollow chamber, and temperature control or fine-tuning of this temperature is based on guiding cooling gas into the chamber via at least one first cooling gas inlet.
[0012] The heating system according to the invention is further simpler than existing heating systems because it requires fewer devices, instruments, pipes, etc., to introduce heating gases, such as hot flue gas, into the kiln muffle furnace compared to implementations in which heating gases are introduced into several muffle furnace zones.
[0013] Compared to hardware designed for higher operating temperatures, the arrangement for introducing cooling gases (such as air or lower-temperature flue gas) is further less complex and costly. Attached Figure Description
[0014] Figure 1 A schematic diagram of an example of a rotary kiln reactor is shown. Figure 2 A schematic diagram of a system according to at least some embodiments of the present invention is shown. Figure 3 A schematic diagram of another system according to at least some embodiments of the present invention is shown. Figure 4 A schematic diagram of another system according to at least some embodiments of the present invention is shown, and Figure 5 A schematic diagram of the heating gas inlet of a system according to at least some embodiments of the present invention is shown. Detailed Implementation
[0015] exist Figure 1The diagram illustrates an example of a rotary kiln reactor. The reactor includes a hollow chamber 2 into which material 23 (e.g., polymer waste) can be fed via a fixed feed system 5 through a feed outlet 7. The material 23 fed into the hollow chamber 2 via at least one feed outlet 7 falls onto the heated inner surface 21 of the rotatable hollow chamber 2 due to gravity. Rotation of the hollow chamber 2 about a rotation axis A causes the material 23 to distribute on at least a portion of the inner surface 21 of the hollow chamber 2. The high-temperature walls of the hollow chamber 2, heated by a heating system 10, heat the material to a pyrolysis reaction temperature, resulting in the thermal decomposition of the material 23 within the hollow chamber 2, thereby converting the material 23 into gas 9 from at least partially pyrolyzed material and residues. The reactor further includes a gas outlet 8 for collecting the product containing gas 9 from the at least partially pyrolyzed material. The reactor is configured such that, before the gas 9 is directed out of the reactor via the gas outlet 8, the gas 9 from at least partially pyrolyzed material within the rotatable hollow chamber 2 is allowed to flow substantially in a direction from the front end 3 to the rear end 4 of the hollow chamber 2 (as indicated by arrow 24).
[0016] exist Figure 2 The diagram shows a schematic representation of system 1 according to at least some embodiments of the invention. System 1 represents a rotary kiln reactor comprising a rotatable hollow chamber 2 having a front end 3 and a rear end 4. The rotatable hollow chamber 2 is typically in the form of an elongated hollow cylinder. The term "elongated" means that the length of the hollow cylinder is substantially greater than the diameter of the hollow cylinder. For example, the length of the hollow cylinder may be 18 m and the diameter of the hollow cylinder may be 2 m. Typically, the length-to-diameter ratio is in the range of 3-20. The hollow chamber 2 is typically made of metal or a metal alloy. The entire hollow chamber 2 is configured to rotate about a rotation axis A. The rotation axis A is typically oriented horizontally or substantially horizontally. The term "horizontally oriented axis" refers to an axis oriented perpendicular to the gravity vector or perpendicular to the normal to the Earth's surface. Similarly, the term "substantially horizontally oriented axis" refers to an axis inclined at a few degrees (e.g., less than 10 degrees) from an axis oriented perpendicular to the gravity vector or perpendicular to the normal to the Earth's surface. The rotational speed of the entire hollow chamber 2 can be, for example, in the range between 0.1 and 5 revolutions per minute (rpm), or, for example, in the range between 1 and 2 rpm.
[0017] System 1 further includes a feeding system 5 configured to feed material 23 into the hollow chamber 2 via at least one feed outlet 7. The feeding system 5 may, for example, include a spray gun having a single feed outlet 7. The spray gun is typically fixed, i.e., not configured to rotate, and the rotatable hollow chamber 2 is configured to rotate about the spray gun. The spray gun may, for example, be in the form of a hollow cylinder. The central axis of the spray gun is typically arranged or oriented coaxially with the axis of rotation A. The spray gun is typically made of metal or a metal alloy. The spray gun may, for example, extend into the hollow chamber 2. System 1 may, for example, be configured to feed polymer waste into the hollow chamber 2 via the feed outlet 7. If the feeding system is an extrusion feeding system, the material 23 is pre-melted, thereby converting the feed into a flowable form that allows it to pass through the spray gun. Alternatively, the material is not pre-melted before being fed into the reactor.
[0018] Material 23 fed into the hollow chamber 2 via at least one feed outlet 7 falls onto the heated inner surface 21 of the rotatable hollow chamber 2 due to gravity. The rotation of the hollow chamber 2 causes the material 23 to be distributed on at least a portion of the inner surface 21 of the hollow chamber 2. The distribution of material 23 on at least a portion of the inner surface 21 of the hollow chamber 2 can be improved by tilting the rotatable hollow chamber 2 a few degrees (e.g., 1 to 5 degrees) from the horizontal axis. In this configuration, the rotatable hollow chamber 2 is arranged substantially horizontally. Furthermore, the rotational speed of the hollow chamber 2 affects the distribution of the material.
[0019] The high-temperature walls of the hollow chamber 2 heat the material 23 to the pyrolysis reaction temperature, causing the material 23 to thermally decompose within the hollow chamber 2, thereby converting the material 23 into gas 9 from at least partially pyrolyzed material and residues. For example, the residues may contain inorganic matter or inorganic contaminants.
[0020] System 1 further includes a gas outlet 8 for collecting products comprising gas 9 from at least partially pyrolyzed material. System 1 is configured to allow gas 9 from at least partially pyrolyzed material within the rotatable hollow chamber 2 to flow in a direction from the front end 3 to the rear end 4 of the hollow chamber 2, as indicated by arrow 24.
[0021] Furthermore, the heating system 10 according to System 1 of the present invention includes a muffle furnace 6. The muffle furnace 6 has a cavity 13 between at least a portion of the outer surface 14 of the rotatable hollow chamber 2 and the wall 20 of the muffle furnace 6. Typically, a cylindrical opening is provided in the muffle furnace 6 such that the rotatable hollow chamber 2 can rotate within the fixed muffle furnace 6. The muffle furnace 6 is typically in the form of a hollow cylinder. The muffle furnace 6 includes a heating gas inlet 11 for guiding heating gas 15 into the cavity 13. The heating gas inlet 11 is located near the rear end 4 of the rotatable hollow chamber 2. Furthermore, the muffle furnace 6 includes a heating gas outlet 12 for guiding the heating gas 15 out of the cavity 13. The heating gas outlet 12 is located near the front end 3 of the rotatable hollow chamber 2. Typically, only a single heating gas inlet 11 and a single heating gas outlet 12 are provided. The heating system 10 is capable of heating the outer surface 14 of the rotatable hollow chamber 2 by the heating gas 15 present in the cavity 13.
[0022] In other words, system 1 is configured to introduce heating gas 15 into cavity 13 and guide the heated gas flow 15 through cavity 13. For example, the heating gas 15 introduced into cavity 13 may be hot flue gas. At heating gas inlet 11, the temperature of the heating gas 15 introduced into cavity 13 may be, for example, 750°C or higher. Heating gas 15 is generally different from gas 9 obtained via gas outlet 8. In other words, gas 9 is generally not used to heat the walls of hollow chamber 2. Gas 9 is generally not introduced into cavity 13. The heated gas flow is guided outside the rotatable hollow chamber 2 so that its direction is substantially opposite to the direction of the gas flow 9 from at least partially pyrolyzed material flowing inside the rotatable hollow chamber 2. Subsequently, the heating gas 15 is guided out of cavity 13 near front end 3 of hollow chamber 2 via heating gas outlet 12.
[0023] exist Figure 3 The diagram shows a schematic representation of another system 1 according to at least some embodiments of the present invention. System 1 includes the above-described combinations. Figure 2The elements described. Optionally, the heating system 10 includes at least one first cooling gas inlet 16, for example, three first cooling gas inlets 16, located between the heating gas inlet 11 and the heating gas outlet 12. Any number of first cooling gas inlets 16 can be provided. At least one first cooling gas inlet 16 is provided for guiding cooling gas 17 into the cavity 13 to mix the cooling gas 17 with the heating gas 15 present in the cavity 13. In other words, the heating system 10 includes at least one first cooling gas inlet 16 downstream of the heating gas inlet 11. At least one first cooling gas inlet 16 may optionally further include an exhaust port for controlling the amount of cooling gas to be introduced into the cavity 13. The cooling gas 17 may be, for example, air, recirculated heating gas, or recirculated flue gas having a lower temperature than the heating gas 15. The high-temperature heating gas 15 is introduced into the cavity 13 of the muffle furnace 6 only near the rear end 4 of the hollow chamber 2 via the heating gas inlet 11, and temperature control or fine-tuning in different parts of the cavity 13 is based on the introduction of cooling gas 17 at at least one different location, preferably at several locations. In other words, mixing the cooling gas 17 with the heating gas 15 causes a decrease in the temperature of the heating gas 15 in the section of the cavity 13 downstream of the corresponding first cooling gas inlet 16.
[0024] exist Figure 4 The diagram shows a schematic representation of another system 1 according to at least some embodiments of the present invention. System 1 includes the above-described combinations. Figure 2 and Figure 3The components described. Furthermore, the muffle furnace 6 includes at least one protrusion 22 that protrudes from the wall 20 of the muffle furnace 6 into the cavity 13 between the heating gas inlet 11 and the heating gas outlet 12; that is, at least one protrusion 22 is fixed. At least one protrusion 22 may be made, for example, of an insulating material. Therefore, the outer surface 14 of the rotatable hollow chamber 2 can remain smooth. As a result, cleaning of the outer surface 14 of the rotatable hollow chamber 2 can be easily performed. Furthermore, at least one sensor (such as a temperature sensor) is provided on the outer surface 14 of the rotatable hollow chamber 2 for measuring surface temperature and / or measuring characteristics using a non-contact sensor, which can be easily performed. A thermocouple or thermoelectric thermometer may, for example, be coupled to the outer surface 14 of the rotatable hollow chamber 2. Alternatively or additionally, a pyrometer or radiation thermometer may be provided for remotely measuring the temperature of the outer surface 14 of the rotatable hollow chamber 2. For example, a protrusion 22 may be provided for each cooling gas inlet 16. The protrusion 22 may, for example, be in the form of a ring or annular structure. Each protrusion reduces the cross-section of the passage or channel between the protrusion 22 and the outer surface of the rotatable hollow chamber 2, through which the heated gas 15 can flow. As a result, turbulence in the heated gas flow increases. The cross-section of the protrusion 22 may vary in different sections of the cavity 13. In this document, the term "blocking point" refers to the point or location where turbulence is generated in the heated gas flow. Each protrusion 22 forms a blocking point to improve the mixing of the heated gas 15 and the cooling gas 17.
[0025] Of course, at least one protrusion may also be provided on the outer surface 14 of the hollow chamber 2, extending into the cavity 13 and generating turbulence in the heated gas flow. For illustration, the protrusion may be a structure that protrudes from the wall 20 of the muffle furnace 6 into the cavity 13 or a structure that protrudes from the outer surface 14 of the rotatable column (referred to herein as the rotatable hollow chamber 2) into the cavity 13.
[0026] exist Figure 5 The diagram shows a schematic of a heating gas inlet 11 of a system 1 according to at least some embodiments of the present invention. The heating gas inlet 11 includes an exhaust port 19 capable of regulating, restricting, or blocking the heating gas flow into the cavity 13. As a result, the amount of heating gas 15 can be adjusted or fine-tuned near the rear end 4 of the hollow chamber 2, where the heating gas 15 is introduced into the cavity 13. For example, in this process, the temperature of the heating gas 15 can be adjusted earlier. Fine-tuning of the wall temperature of the rotatable hollow chamber 2 in different sections or regions of the rotatable hollow chamber can be further improved by guiding cooling gas 17 into the cavity 13, such as in combination with… Figure 3 As described and shown.
[0027] Optionally, the second cooling gas inlet 18 may be connected to the heating gas inlet 11 to mix the cooling gas 17 with the heating gas 15 before guiding the mixture into the cavity 13 of the muffle furnace 6. The second cooling gas inlet 18 may optionally include an exhaust port capable of regulating, restricting, or blocking the cooling gas flow. As a result, the temperature of the heating gas 15 can be regulated or fine-tuned near the rear end 4 of the hollow chamber 2, where the heating gas 15 is introduced into the cavity 13.
[0028] It should be understood that the embodiments of the present invention disclosed herein are not limited to the specific structures, process steps, or materials disclosed herein, but are extended to their equivalents, as will be recognized by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
[0029] Throughout this specification, any reference to an embodiment or embodiment means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily refer to the same embodiment. Precise numerical values are also disclosed when terms such as about or substantially refer to numerical values.
[0030] As used herein, for convenience, multiple items, structural elements, constituent elements, and / or materials may be presented in a common list. However, these lists should be interpreted as if each member of the list were individually identified as a separate and unique member. Therefore, without indication to the contrary, individual members of such lists should not be construed as actual equivalents of any other member of the same list solely based on their presentation in the common group. Furthermore, various embodiments and examples of the invention, along with alternatives to their various components, may be mentioned herein. It should be understood that such embodiments, examples, and alternatives should not be construed as actual equivalents of each other, but rather as separate and autonomous manifestations of the invention.
[0031] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Various specific details, such as examples of length, width, shape, etc., are provided in the specification to provide a thorough understanding of embodiments of the invention. However, those skilled in the art will recognize that the invention can be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the invention.
[0032] While the foregoing examples illustrate the principles of the invention in one or more specific applications, it will be apparent to those skilled in the art that numerous modifications in form, use, and detail of the implementations can be made without inventive skill and without departing from the principles and concepts of the invention. Therefore, the invention is not intended to be limited except by the appended claims.
[0033] The verbs “to comprise” and “to include” are used herein as open-ended restrictions, neither excluding nor requiring the presence of any unlisted features. Unless otherwise expressly stated, the features listed in the dependent claims may be freely combined with each other. Furthermore, it should be understood that the use of “an” or “a” (i.e., the singular form) throughout this document does not exclude a plurality.
[0034] Industrial applicability
[0035] At least some embodiments of the present invention have industrial applications in the heating of rotary kiln reactors.
[0036] Reference Symbol List
[0037] 1 System
[0038] 2 Rotatable hollow chamber
[0039] 3. Frontend
[0040] 4. Backend
[0041] 5. Feeding System
[0042] 6 Muffle Furnace
[0043] 7. Feed Inlet / Outlet
[0044] 8 Gas outlet
[0045] 9. Gases from at least partially pyrolyzed materials
[0046] 10 Heating System
[0047] 11 Heating gas inlet
[0048] 12 Heating gas outlet
[0049] 13 cavities
[0050] 14. The outer surface of the rotatable hollow chamber
[0051] 15 Heating Gas
[0052] 16 First Cooling Gas Inlet
[0053] 17 Cooling Gas
[0054] 18 Second Cooling Gas Inlet
[0055] 19 Exhaust port
[0056] 20. Wall of the muffle furnace
[0057] 21 Inner surface
[0058] 22 convex part
[0059] 23 Materials
[0060] 24. Direction of gas flow from at least partially pyrolyzed material.
[0061] 26. Direction of gas flow for heating
[0062] A. Rotation axis.
Claims
1. A system (1), comprising: - A rotatable hollow chamber (2) having a front end (3) and a rear end (4). - A feeding system (5), which is configured to feed material into the hollow chamber (2) via at least one feed outlet (7). - Gas outlet (8), said gas outlet for collecting products containing gas (9) from at least partially pyrolyzed material, wherein said system (1) is configured to allow said gas (9) from at least partially pyrolyzed material to flow in said rotatable hollow chamber (2) in a direction from said front end (3) to said rear end (4), - Heating system (10), including: ○ Muffle furnace (6), which encloses at least a portion of the rotatable hollow chamber (2), thus providing a cavity (13) between at least a portion of the outer surface (14) of the rotatable hollow chamber (2) and the wall (20) of the muffle furnace (6). ○The heating gas inlet (11) for guiding the heating gas (15) into the cavity (13) is located near the rear end (4) of the rotatable hollow chamber (2), and the heating gas outlet (12) for guiding the heating gas (15) out of the cavity (13) is located near the front end (3) of the rotatable hollow chamber (2). Its features are, The heating system (10) further includes at least one first cooling gas inlet (16) located between the heating gas inlet (11) and the heating gas outlet (12). The first cooling gas inlet is used to guide cooling gas (17) into the cavity (13) to mix the cooling gas (17) with the heating gas (15) present in the cavity (13). The heating gas inlet (11) includes an exhaust port (19), which can regulate, restrict or block the heating gas flow into the cavity (13).
2. The system (1) according to claim 1, wherein, The heating system (10) is capable of heating the outer surface (14) of the rotatable hollow chamber (2) by means of heating gas (15) present in the cavity (13).
3. The system (1) according to claim 2 or 3, wherein, The system (1) is configured such that the heated gas (15) is directed via the cavity (13) outside the rotatable hollow chamber (2) in a direction substantially opposite to the direction of the gas (9) flowing from at least partially pyrolyzed material in the rotatable hollow chamber (2).
4. The system (1) according to any one of claims 1-3, wherein, The heating gas (15) is different from the gas (9) from the material that has been at least partially pyrolyzed.
5. The system (1) according to any one of claims 1-4, wherein, The muffle furnace (6) includes at least one protrusion (22) that protrudes from the wall (20) of the muffle furnace (6) into the cavity (13) and / or from the outer surface (14) of the rotatable hollow chamber (2) into the cavity (13).
6. The system (1) according to claim 5, wherein, The at least one protrusion (22) is arranged downstream of the heating gas inlet (11) and downstream of the at least one first cooling gas inlet (16).
7. The system (1) according to any one of claims 1-6, wherein, The muffle furnace (6) is made of steel or refractory material or a combination of both.
8. The system (1) according to any one of claims 1 to 7, wherein, The heating system (10) includes a second cooling gas inlet (18) connected to the heating gas inlet (11).
9. A method for heating a rotatable hollow chamber (2), the method comprising: - Provides a rotatable hollow chamber (2) having a front end (3) and a rear end (4). - Material is fed into the hollow chamber (6) via at least one feed outlet (7) of the feeding system (5). - The product, comprising gas (9) from at least partially pyrolyzed material, is collected through gas outlet (8), wherein the gas (9) from at least partially pyrolyzed material is allowed to flow in the rotatable hollow chamber (2) from the front end (3) to the rear end (4). - A muffle furnace (6) is provided, which encloses at least a portion of the outer surface (14) of the rotatable hollow chamber (2), thus providing a cavity (13) between at least a portion of the outer surface (14) of the rotatable hollow chamber (2) and the wall (20) of the muffle furnace (6). - Heating gas (15) is guided into the cavity (13) via a heating gas inlet (11), wherein the heating gas inlet (11) is located near the rear end (4) of the rotatable hollow chamber (2), and - The heating gas (15) is guided away from the cavity (13) via the heating gas outlet (12), wherein the heating gas outlet (12) is located near the front end (3) of the rotatable hollow chamber (2). Its features - Cooling gas (17) is guided into the cavity (13) via at least one first cooling gas inlet (16), and the cooling gas (17) is mixed with the heating gas (15), wherein at least one cooling gas inlet (16) is arranged between the heating gas inlet (11) and the heating gas outlet (12), and - Use the exhaust port (19) to regulate, block or restrict the flow of heated air into the cavity (13).
10. The method according to claim 9, the method comprising heating the outer surface (14) of the rotatable hollow chamber (2) by means of heating gas (15) present in the cavity (13).
11. The method according to claim 9 or 10, the method comprising guiding a heated gas flow of the heated gas (15) outside the rotatable hollow chamber (2) in a direction substantially opposite to the direction of the gas flow (9) from at least partially pyrolyzed material.
12. The method according to any one of claims 9-11, the method comprising increasing turbulence in the heated gas flow by utilizing at least one protrusion (22) protruding from the wall (20) of the muffle furnace (6) and / or from the outer surface (14) into the cavity (13).