Process device for the thermal and / or chemothermal treatment of process material, and corresponding method

Abstract

The invention relates to a process device for the thermal and / or chemothermal treatment of process material, comprising a housing in which a process chamber is provided, wherein the process material can be subjected to the thermal and / or chemothermal treatment in the process chamber using a process gas, and comprising a conveying device by means of which the process material can be conveyed through the process chamber. According to the invention, the process chamber is designed as an inner muffle and is at least partly enclosed by a temperature-control chamber having a temperature-control gas located therein, the process chamber having a process gas circulation function and the temperature-control chamber having a temperature-control gas circulation function. The invention further relates to a method for controlling the temperature of a process gas and a process material in a process chamber for a thermal and / or chemothermal treatment of the process material.

Description

[0001]

[0002] Process device for the thermal and / or chemothermal treatment of process material and corresponding method

[0003] BACKGROUND OF THE INVENTION

[0004] 1. Field of the invention

[0005] The invention relates to a process device for the thermal and / or chemothermal treatment of process material, comprising a housing in which a process chamber is arranged, wherein the process material can be subjected to thermal and / or chemothermal treatment by means of a process gas in the process chamber, and a conveying device with which the process material can be conveyed through the process chamber, as well as a method for temperature control of a process gas and a process material in a process chamber for a thermal and / or chemothermal treatment of the process material.

[0006] 2. Description of the state of the art

[0007] Such processes are used in the industrial-scale production of anode materials, for example for batteries, in industrial furnaces. For these anode materials, porous carbon material with a very high surface area and pore sizes ranging from < 2 nm to 50 nm is produced. First, the starting material is carbonized in a pyrolysis process to create an initial porous carbon framework. Then, the process material is heated in an atmosphere of oxide compounds, such as superheated steam, CO2, or O2, until the oxide reacts with the carbon to form carbon monoxide and hydrogen. Silicon can then be incorporated into the carbon substrate. For this, the process material is heated to temperatures between 300 °C and 500 °C and coated with a flammable or...The system is exposed to an explosive process gas consisting of a silicon compound. The silicon is deposited in the pore structure of the carbon sub-O&P.

[0008] P 70367 WO - 2 - 12.08.2025 starts and improves its properties with regard to specific capacity and its behavior under long-term use in batteries.

[0009] Several boundary conditions must be observed in the described process of silicon infiltration into the carbon backbone of the process material. On the one hand, precise temperature control of the infiltration process is crucial. For this, the process material and the process gas must be kept within a narrow temperature range. It is desirable to avoid large local temperature fluctuations, so-called hotspots. Locally overheated surfaces lead to undesirable deposits from the process gas, which can result in shorter maintenance intervals for cleaning the process equipment and excessive process gas consumption.

[0010] SUMMARY OF THE INVENTION

[0011] It is an object of the invention to provide a process device and a method of the type mentioned at the outset in which the process chamber does not have to be regularly heated for cleaning and / or which have a lower process gas consumption.

[0012] This problem is solved by a process device according to independent claim 1.

[0013] The process device according to the invention for the thermal and / or chemothermal treatment of process material, for example for the production of anode material, for example for batteries, comprises a housing in which a process chamber is arranged, wherein the process material can be subjected to thermal and / or chemothermal treatment by means of a process gas in the process chamber. Furthermore, the process device comprises a conveying device with which the process material can be conveyed through the process chamber.

[0014] According to the invention, the process chamber is designed as an inner muffle and is at least partially enclosed by a temperature control chamber containing a temperature control gas. The Pro- O&P

[0015] P 70367 WO - 3 - 12.08.2025 The process room has a process gas recirculation system and the temperature control room has a temperature control gas recirculation system.

[0016] These two measures – enclosing the process chamber (designed as an inner muffle) with the temperature control chamber and circulating the atmosphere within both chambers – result in a particularly homogeneous and, in particular, hot-spot-free temperature distribution within the process chamber, and thus in exceptionally uniform temperature control of the process material. The partial enclosure of the process chamber by the temperature control chamber facilitates heat transfer from the temperature control gas in the chamber to the process chamber via convection. Circulating both the temperature control gas and the process gas ensures uniform temperature control both spatially and temporally. The process chamber and the process gas exhibit a very homogeneous temperature distribution at all times. The formation of localized overheating ("hot spots") is largely avoided or minimized.

[0017] In this context, "at least partial enclosure" means that, where possible, all external surfaces of the inner muffle are enclosed by the temperature control chamber. This may exclude, for example, inlet and outlet airlocks, holding structures, or feedthroughs for the supply or removal of process materials or for measuring or handling tasks.

[0018] The term "inner muffle" as a technical term refers to a structure for creating the process space, which is suitable for heating to the required temperatures and for receiving the process material (for example in suitable containers or carriers), without having its own active temperature control option such as heating elements.

[0019] In a preferred embodiment of the invention, the process chamber and the temperature control chamber are designed such that the temperature control of the process chamber is achieved—essentially—indirectly via the temperature control of the temperature control chamber, in particular via the temperature control gas in the temperature control chamber. This is intended to prevent the undesirable formation of hotspots.

[0020] P 70367 WO - 4 - 12.08.2025 To reduce the load, direct heating of the process chamber or the inner muffle is omitted. There are no heating elements in the process chamber or the inner muffle, nor on the outer wall of the process chamber or the inner muffle. Heating elements may be present in the process chamber to generate a base heating load, but they are designed in such a way that no hotspots can occur.

[0021] The heating of the process chamber or inner muffle is indirect. The temperature control gas in the temperature control chamber is in contact with the outer wall of the inner muffle or process chamber and transfers the heat contained in the temperature control gas to the outer wall of the process chamber or inner muffle.

[0022] In a further development of the process device, it is provided that the process gas circulation and the temperature control gas circulation occur at least partially in opposite directions. It is intended that the flow paths of the temperature control gas in the temperature control chamber do not, if possible, run parallel to the flow paths resulting from the circulation of the process gas in the process chamber. In particular, in the areas where the temperature control chamber surrounds the process chamber, flow paths of the temperature control gas are located on the outside of a wall of the process chamber or the inner muffle, and at the same location on the inside of the wall, flow paths of the process gas are located. Here, it is advantageous if these flow paths do not run parallel and in the same direction, but rather, if possible, at an angle, not at the same velocity, and advantageously in opposite directions, i.e., in the extreme case, antiparallel.This ensures that heat transfer between the heat transfer medium – in this case, the heating gas – and the object being heated – in this case, the process chamber and, indirectly, the process material – occurs in a very uniform manner. Individual local overheatings, where undesirable material deposition could occur due to the higher temperature, do not occur or only to a very limited extent.

[0023] In one specific embodiment of the invention, the process gas is a silicon compound. Furthermore, in one embodiment, the temperature control gas is an inert gas, and in particular nitrogen. Uniform temperature control is important for a process gas suitable for silicon deposition, as otherwise undesirable deposits will not occur at the O&P.

[0024] P 70367 WO - 5 - 12.08.2025

[0025] The product itself, but in the process room, resulting on the one hand in a loss of separating material and on the other hand in the need for regular cooling and cleaning of the process room.

[0026] Specifically, in one embodiment, the conveying device can be designed as a push track. Furthermore, the process device can include carriers on or in which the process material can be stored and conveyed through the process chamber. The carriers can be designed as stackable containers, for example, tubs. The stacks of carriers can be stored on push plates and conveyed through the process chamber by means of a push device.

[0027] In an advantageous embodiment, the temperature control chamber includes a temperature control device. For example, the temperature control device comprises a heating device and / or a cooling device, in particular both a heating device and a cooling device. In this way, the temperature control gas can be easily controlled.

[0028] The problem is also solved by a method according to the independent method claim. The method comprises the steps of tempering a tempering gas in a tempering chamber which at least partially surrounds the process chamber, circulating the tempering gas in the tempering chamber, and circulating the process gas in the process chamber such that the heat of the tempering gas is transferred to the process chamber and the process gas by convection. In this way, the advantages already explained in connection with the process apparatus according to the invention can also be realized within the framework of a method.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. These show:

[0031] Figure 1 shows a schematic cross-sectional view of a process device for the thermal and / or chemothermal treatment of process material; as well as O&P.

[0032] P 70367 WO - 6 - 12.08.2025

[0033] Figure 2 shows a schematic flowchart of a process for temperature control of a process gas.

[0034] DESCRIPTION OF PREFERRED EXAMPLES

[0035] Figure 1 illustrates, in a schematic cross-sectional view, a process device 10 for the thermal or chemothermal treatment of process material. The process device comprises a housing 12. The housing 12 essentially has the basic shape of an elongated cuboid, the longitudinal axis of which extends essentially along a conveying direction that, in the representation of Figure 1, runs perpendicular to the plane of the drawing. The housing can, for example, be a welded steel construction made of mild steel. Several housing elements can be connected in series to form a processing stage.

[0036] A conveying device 14 is arranged in the housing 12 of the process device 10. In the illustrated embodiment, the conveying device 14 comprises two push or slide tracks 16 arranged side by side in the conveying direction (only schematically indicated), on which push plates 18 can be positioned. The arrangement of the push tracks 16 side by side is merely exemplary. A single push track or more than two push tracks can also be provided. The push track(s) can also connect several housing elements one behind the other.

[0037] On the push plates 18, workpiece carriers 20 – here designed as process troughs – are stacked one above the other. The process material – for example, carbon powder – can be stored in the workpiece carriers 20. The stacks 22 are conveyed by means of the push plates 18 through the process device 10, in particular through a process chamber 24, by means of a pusher (not shown).

[0038] Process chamber 24 is designed as an inner muffle 26. The inner muffle 26 can, for example, be a gas-tight welded steel structure. The inner muffle 26 has a circulation device 28 for circulating the atmosphere and, in particular, the process gas in process chamber 24. O&P

[0039] P 70367 WO - 7 - 12.08.2025

[0040] The circulation device 28 can, for example, be a fan or another suitable device for atmospheric circulation. The inner muffle 26 does not have its own heating device, but is heated by the temperature control chamber 30, which at least partially surrounds the process chamber 24.

[0041] The temperature control chamber 30 at least partially surrounds the process chamber 24, meaning that significant outward-facing surfaces of the process chamber 24 are enclosed by the temperature control chamber 30. For example, inlet and outlet airlocks (not shown) and the transitions to an adjacent housing element are not enclosed by the temperature control chamber 30. The process chamber 24 may have supports or penetrations at the bottom, or optionally to the side or top, which are necessary for the stability or functionality of the process device 10. As shown in Fig. 1, the side surfaces 32, the top 34, and the bottom 36 of the inner muffle 26 are enclosed by the temperature control chamber 30. The process chamber 24 may share its outer wall with the temperature control chamber 30 (there, it serves as the inner wall), as seen, for example, in the side walls 32 or the bottom 36 of the process chamber.Alternatively, the process chamber 24 can also have its own outer wall, which is not identical to the inner wall of the temperature control chamber 30 - see, for example, the top 34 of the inner muffle 26.

[0042] The temperature control chamber 30 includes a temperature control gas blower 38 for circulating the temperature control gas and a measuring device 39 for determining the temperature of the temperature control gas. Furthermore, a temperature control device 40 is provided in the temperature control chamber 30. The temperature control device 40 comprises a heating device 42 and a cooling device 44. Both the heating device 42 and the cooling device 44 are designed as heating and cooling coils, respectively. A suitably tempered heating or cooling medium is supplied to the respective device 42, 44 and guided through corresponding rods or lines in the airflow of the temperature control gas. There, the temperature control gas is continuously circulated past the heating and cooling coils by means of the temperature control chamber circulation system 38.

[0043] In this way, the temperature control gas can be heated (heating device 42) or cooled (cooling device 44) and kept within a desired temperature range.

[0044] P 70367 WO - 8 - 12.08.2025 den. In the embodiment shown in Figure 1, a chemically inert gas such as nitrogen (N2) is used as the temperature control gas. Other chemically inert gases or mixtures can also be used.

[0045] A suitable silicon compound is used as the process gas in the process apparatus shown in Figure 1. Other gases that enable the deposition of substances within a specific temperature range can also be used. Under normal operating conditions, the temperature range of process chamber 24 is between 300 °C and 500 °C. The precise limits of the temperature range depend on the desired process outcome and can, for example, cover a range of ±20 °C, or optionally a range of ±50 °C.

[0046] Process unit 10 can be part of a furnace system for the production of anode material for batteries. As mentioned, the infiltration step takes place in process unit 10 as part of a corresponding manufacturing process. In this manufacturing process, the process material is prepared by pretreating powdered starting materials and subjecting them to pyrolysis. The carbon material produced in this way is then activated. During activation, a portion of the carbon material is oxidized, resulting in the desired pore size and pore density in the process material.

[0047] Subsequent processing steps after activation of the process material may include grinding into powder form, the aforementioned introduction / infiltration of silicon into the carbon material, and passivation of the process material.

[0048] The process chamber 24 can be temperature-controlled by means of a temperature probe 44. The process gas is introduced into the process chamber 24 via a supply line 46; any gaseous reactants can be removed via a suitable extraction system (not shown).

[0049] The temperature control gas recirculation 38 generates an airflow in the temperature control chamber 30, which is illustrated by arrows 48. In Figure 1, this flow runs counterclockwise around the process chamber 24. In the process chamber 24 itself, the process gas recirculation 28, i.e., the recirculation device 28, ensures the recirculation of the process gas.

[0050] P 70367 WO - 9 - 12.08.2025 according to arrows 50. The process gas is introduced into the process chamber 24 on the outer sides 32 according to arrows 50, flows from there into the center of the process chamber, and is extracted from there via the bottom 36 and returned to the outer sides. As the process gas flows into the center, it passes through or over the process material, for example, located in the workpiece carriers 20.

[0051] As can be seen in Figure 1, a flow direction opposite to the flow direction of the temperature control gas is created on the left side of the process chamber 24 according to arrows 48. The temperature control gas flows downwards on this side, while there is an upward flow in the process chamber 24 on this side.

[0052] On the right side, however, the flow direction is partially the same: Both flows, in the process chamber 24 and in the temperature control chamber 30, run upwards. Due to the different flow velocities and the fact that the process gas flows essentially between the workpiece carriers 20 towards the center of the process chamber, a very uniform heat transfer from the temperature control gas to the process gas via the wall of the inner muffle 26 is also possible on the right side of the process chamber 24 in Figure 1.

[0053] Overall, a very homogeneous temperature distribution can thus be achieved throughout the entire process chamber 24. In particular, hotspots are avoided, so that the process gas does not condense at such hotspots, but primarily on the process material itself. The separation of process chamber 24 from the temperature control chamber 32 via the walls 32, 34, 36 of the inner muffle 26 creates two separate chambers, which partially share the wall of the inner muffle 26. Process chamber 24 is located inside the muffle 26. The reaction between the process material and the process gas takes place in this chamber. In the heating chamber / temperature control chamber 32, a protective gas, in this case nitrogen, is heated or cooled. The counter-circulation of the gases (process gas / temperature control gas) in the two chambers 24 and 32 allows for gentle heat or cold transfer via convection. Hotspots in process chamber 24 and on the inner muffle 26 are largely avoided. O&P

[0054] P 70367 WO - 10 - 12.08.2025

[0055] By preventing a reaction between the process gas and hot surfaces inside process chamber 24, clogging of the surfaces of process chamber 24 is avoided. It is also advantageous that there are no heating elements in process chamber 24 where hotspots can easily and quickly form. This results in a significantly longer service life, as the process device 10 does not need to be regularly heated or cooled for cleaning. This also results in lower process gas consumption, since the process gas only reacts with the process material itself and does not accumulate at hotspots.

[0056] In order to achieve a better even distribution of temperature in the process chamber 24, the fans - i.e. the temperature control gas circulation devices 38 - can be arranged alternately on the left and right with respect to the conveying direction in the case of housing modules connected in series.

[0057] Figure 2 illustrates a process for temperature control of a process gas and a process material in a process chamber for thermal and / or chemothermal treatment of the process material in a schematic flowchart. In the process, in step S1, a temperature control gas is tempered in a temperature control chamber that at least partially surrounds the process chamber. The temperature control gas is circulated in the temperature control chamber (S2). Simultaneously, the process gas is circulated in the process chamber (S3).

[0058] This ensures that the heat from the temperature control gas is transferred to the process chamber and the process gas via convection (S4).

Claims

O&P P 70367 WO - 11 - 12.08.2025 PATENT CLAIMS 1. Process device (10) for the thermal and / or chemothermal treatment of process material, comprising a) a housing (12) in which a process chamber (24) is arranged, wherein the process material can be subjected to thermal and / or chemothermal treatment by means of a process gas in the process chamber (24), and b) a conveying device (14) with which the process material can be conveyed through the process chamber (24), characterized in that c) the process chamber (24) is designed as an inner muffle (26) and is at least partially enclosed by a temperature control chamber (30) containing a temperature control gas, and d) the process chamber (24) has a process gas recirculation (28) and the temperature control chamber (30) has a temperature control gas recirculation (38).

2. Process device according to claim 1, wherein the process chamber (24) and the temperature control chamber (30) are designed such that the temperature control of the process chamber (24) is carried out indirectly via the temperature control of the temperature control chamber (30).

3. Process device according to one of the preceding claims, wherein the process gas circulation (28) and the temperature control gas circulation (38) are at least partially spatially opposed.

4. Process apparatus according to one of the preceding claims, wherein the process gas comprises a silicon compound and / or the tempering gas is an inert gas. O&P P 70367 WO - 12 - 12.08.2025 5. Process device according to one of the preceding claims, wherein the conveying device (14) is designed as a push track (16).

6. Process device according to one of the preceding claims, with carriers (20) on or in which the process material can be stored and conveyed through the process space (24).

7. Process apparatus according to one of the preceding claims, wherein the temperature control chamber (30) comprises a temperature control device (40).

8. Process device according to claim 7, wherein the temperature control device (40) comprises a heating device (42) and / or a cooling device (44).

9. Process device according to one of the preceding claims, wherein the process chamber (24) can be operated in a temperature range between 300 °C and 500 °C during normal operation.

10. Method for temperature control of a process gas and a process material in a process chamber for thermal and / or chemothermal treatment of the process material, comprising the following steps: - Tempering a tempering gas in a tempering chamber which at least partially surrounds the process chamber (S1), - Circulating the temperature control gas in the temperature control chamber (S2), Circulating the process gas in the process chamber (S3) such that the heat of the tempering gas is transferred to the process chamber and the process gas by means of convection (S4)t.

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