Stiftofen

Abstract

Pin oven (1) for drying a coating of at least one tubular container (2), comprising at least: - an oven interior (3) in which an approximately vertically oriented transport plane (4) is arranged, wherein an inlet chamber (5) is arranged upstream of the transport plane (4) and an outlet chamber (6) is arranged downstream of the transport plane (4) in the oven interior (3), - at least one U-shaped channel (7) which runs in the transport plane (4) and has an open side (12) towards the outlet chamber (6), - a conveying device (8) with a plurality of pins (9), wherein the pins (9) each project at least partially into the U-shaped channel (7) and are provided and configured for holding a tubular container (2), - at least one circulation device (10) which is arranged at least partially in the oven interior (3) and is provided and configured for moving a fluid located in the oven interior (3),- at least one first flow guide device (11) which is provided and configured to deflect the fluid in the area of ​​the open side (12) of the U-shaped channel (7).

Description

The invention relates to a pin oven for drying a coating on at least one tubular object. In particular, the invention can be used for curing coatings on beverage cans. In the production of metal cans for, for example, carbonated beverages, it is common practice to coat the regularly cylindrical surface of the can with a coating, such as a lacquer or paint. To ensure the durability of this coating, it must be cured regularly after application. Pin ovens can be used for this purpose, in which the coating is heated convectively and thus dried, cured, or even baked on. Pin ovens typically feature a chain conveyor that guides pins attached to a chain along a defined and usually multi-winding, particularly meandering, path through the oven's interior. Normally, the cans are placed on the pins in a semi-finished state, i.e., still open at one end but already coated, and conveyed through the oven interior by the chain conveyor for drying. To increase the efficiency and uniformity of convective heating, the cans mounted on the pins can be guided through a channel, open at one end and essentially U-shaped, as they traverse the oven interior. The walls of this channel are perforated to promote a relatively uniform flow of air across the can surface, particularly the outer bottom and body. When guiding cans in such a U-shaped channel, it must be considered that, due to potential variations in the can shape and / or the relatively imprecise positioning of the can on the pin, a safety or minimum distance must always be maintained between the can and the channel walls of the U-shaped channel. However, it has been observed that this minimum distance results in uneven heating of certain sections of the can, despite the uniform airflow achieved through the perforation of the channel walls. This was particularly noticeable at the open end of the can, which faces the open side of the U-shaped channel or may even protrude slightly from it. This end section heats up more slowly than other parts of the can, resulting in a longer overall heating time. US patent 5,353,520 discloses a pin furnace for cans. US patent 2014 / 0259731 A1 discloses a pin furnace with a continuous U-shaped channel. Starting from this premise, the object of the present invention is to at least partially solve the problems described with reference to the prior art. In particular, a pin furnace for drying a coating of at least one tubular container is to be provided, which allows for the most uniform possible heating of the container and the most uniform possible drying of the coating, while at the same time allowing for the shortest possible heating time or residence time of the container in the pin furnace. In addition, the pin furnace should be as cost-effective and space-saving to manufacture as possible, easy to transport, and resource-efficient or energy-efficient to operate. Furthermore, the pin furnace should have a higher thermal and / or fluid-flow efficiency than conventional pin furnaces. These objectives are achieved by the features of the independent claims.Further advantageous embodiments of the solution proposed here are specified in the dependent claims. It should be noted that the features listed individually in the dependent claims can be combined with one another in any technologically meaningful way and define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, which also presents further preferred embodiments of the invention. A pin oven contributes to drying a coating of at least one tubular container, comprising at least: - an oven interior in which an approximately vertically oriented transport plane is arranged, wherein an inlet chamber and an outlet chamber are arranged upstream of the transport plane in the oven interior, - at least one U-shaped channel running in the transport plane and having an open side towards the outlet chamber, - a conveying device with a plurality of pins, wherein the pins each project at least partially into the U-shaped channel and are provided and configured to hold a tubular container, - at least one circulation device, which is arranged at least partially in the oven interior and is provided and configured to move a fluid located in the oven interior, - at least one first flow guide device,which is designed and equipped to deflect the fluid in the area of ​​the open side of the U-shaped channel. The pin furnace is particularly suitable for operation within a temperature range of 100°C to 300°C, preferably from 150°C to 250°C. A suitably heated fluid can circulate within the furnace interior, particularly around a substantially horizontal axis. The fluid, normally heated by a heating device, can first be accelerated by the circulation device as it travels through the furnace interior and then, particularly in the sequence specified below, flow through the inlet chamber, the U-shaped channel, and the outlet chamber. Optionally, it can be provided that, after passing through the outlet chamber, the fluid is recirculated, particularly along the heating device (in a closed loop), to the circulation device and / or the inlet chamber. Preferably, the tubular container is made of metal or of sheet metal. The tubular container is preferably a can, a tube, or a sleeve-like sheet metal packaging. Preferably, the tubular container is open at one end, particularly at (only) one end. Furthermore, preferably, the tubular container is (pre-)coated, particularly with a water- or solvent-based coating. The coating can be a covering, such as at least one primer layer, a varnish layer, and / or a paint layer. Preferably, the approximately vertically oriented transport plane is oriented vertically or inclined at an angle of up to 25° [degrees], particularly up to 15° or even up to 13°, relative to a vertical plane. Particularly preferred is the approximately vertically oriented transport plane inclined at an angle in the range of 5° to 25°, particularly up to 10° to 15° or even up to 10° to 13°, relative to a vertical plane. Preferably, the U-shaped channel in the transport plane has at least one upper curved section, at least one lower curved section, and (between) at least one straight section connecting the upper curved section to the lower curved section.Preferably, the channel is formed by at least one U-shaped channel with a channel bottom wall aligned parallel to the transport plane and two opposing channel side walls extending away from the channel bottom wall and, in particular, towards the discharge chamber. The U-shaped channel is open opposite the channel bottom wall, or has an open side. Preferably, the channel walls forming the U-shaped channel are perforated, in particular formed with at least one perforated sheet. This allows a fluid flow, especially a uniform one, to flow through the channel walls. The perforation of the channel walls can have (round or oval) holes and / or slots. Particularly preferred is the channel bottom wall perforated with slots and / or holes, and the channel side walls perforated with holes. The conveying device preferably comprises at least one chain conveyor. More preferably, the conveying device comprises at least one, in particular a continuously driven, conveyor chain on which a plurality of pins are held. The pins can extend from the conveyor chain in a manner essentially perpendicular to the transport plane. Particularly for holding the tubular container, each pin can contact an inner surface of the container, in particular an inner surface of a closed end face of the container. The circulation device can have at least one (driven) impeller to which a plurality of impeller blades are attached. Preferably, the circulation device is formed with at least one blower, (recirculating air) fan, or compressor. More preferably, the circulation device has a housing, in particular an impeller housing. The at least one impeller can be arranged in the impeller housing. Furthermore, the circulation device can have at least one (inlet) nozzle. The (inlet) nozzle can be arranged upstream of the at least one impeller or upstream of the impeller. Preferably, the (inlet) nozzle is integrated into the housing or is a separate component that is held and / or attached to a frame of the circulation device in the furnace interior by means of a nozzle holder.Preferably, the circulation device is designed and configured to accelerate the fluid to a flow velocity in the range of 20 to 40 m / s [meters per second], particularly in the area of ​​the U-shaped channel. Preferably, the circulating device comprises a frame. At least one impeller can be mounted on and / or within the frame. Preferably, the circulating device has at least one impeller, which is particularly preferably held within the frame by means of a shaft. The frame can extend at least partially into the interior of the furnace. Preferably, the frame has at least one (fastening and / or mounting) plate and / or at least one brace. At least one first plate of the frame is preferably (directly) connected to an interior wall of the furnace. Particularly preferably, the first plate is arranged (directly) on the interior wall of the furnace or even embedded in the interior wall of the furnace. The at least one impeller can be mounted on the first plate. A second plate of the frame can be arranged and / or mounted within the interior of the furnace, particularly aligned parallel to the first plate.Preferably, the frame has at least two or even at least four struts. The struts can be aligned parallel to each other. Preferably, the struts extend, in particular from the first plate, into the interior of the furnace. The struts can extend between the first plate and the second plate. In particular, the struts and / or the second plate serve to hold at least one inlet nozzle. Preferably, an inlet nozzle is arranged and / or attached to an end of the struts that points into the interior of the furnace. At least one of the struts can be arranged within an impeller housing and / or extend through the impeller housing. The impeller housing can be arranged and / or attached to the frame of the recirculation device. Preferably, there is a (maximum) distance between a strut of the frame and a (radially outermost point orThe outer diameter of at least one impeller of the circulation device is in the range of 1 mm to 100 mm, in particular from 15 mm to 75 mm. Such a small distance allows for a particularly advantageous integration of the spiral housing proposed here into the circulation device. The fluid can be a gas or a gas mixture. Furthermore, the gas or gas mixture can be at least partially saturated with a liquid, such as water. Preferably, the fluid is air. Alternatively or cumulatively, the fluid can consist of an inert gas, such as nitrogen. The at least one first flow guide device is designed and configured to deflect the fluid in the region of an open side of the U-shaped channel. In this context, the fluid is deflected, in particular, by directing at least a portion of the fluid and / or a portion of the fluid flow passing through the U-shaped channel (from the inlet chamber to the outlet chamber) from one or both channel side walls towards the center of the channel. Preferably, this deflection occurs shortly before, during, and / or shortly after the fluid flows through the open side of the U-shaped channel. In an advantageous embodiment, it is proposed that the at least one first flow guide device is provided and configured to direct at least a portion of the fluid flowing towards the open side of the U-shaped channel towards a container end section facing the outflow chamber of a container that can be mounted on one of the pins. The container end section facing the outflow chamber is, in particular, a portion of the container where a cut edge and / or the (only) open end face of the container is provided. In an advantageous embodiment, it is proposed that the at least one first flow guide has a plurality of flowable openings arranged in a backflow wall located in the outflow chamber. Preferably, the first flow guide has at least 100 or even at least 200 openings. The openings are more preferably round or oval in shape. The openings can (each or all) have an opening diameter in the range of 0.1 mm to 100 mm, preferably from 0.1 mm to 50 mm, or even from 2 mm to 25 mm. The backflow wall is formed, in particular, with at least one sheet metal plate arranged in the outflow chamber. Preferably, the backflow wall is aligned substantially parallel to the transport plane. Preferably, the backflow wall is arranged at a distance from the U-shaped channel.A distance of 1 cm to 30 cm, and particularly 2 cm to 30 cm, between the open side of the U-shaped channel and the backflow wall is particularly preferred. Furthermore, at least part of the conveying device can be arranged between the U-shaped channel and the backflow wall. Preferably, the backflow wall overlaps and / or covers the entire length of the U-shaped channel. Preferably, the at least one first flow guide is formed with at least one arrangement of flow-through openings. These flow-through openings are preferably arranged in a backflow wall located in the outflow chamber. Furthermore, preferably, the (each) arrangement of flow-through openings is suitable and configured to at least partially constrict at least a portion of the fluid flow exiting the U-shaped channel. This allows the fluid flowing out of the U-shaped channel, particularly in the region of the open side of the U-shaped channel, to be guided closer to and / or along the container. In an advantageous embodiment, it is proposed that the openings are arranged (essentially) only in an opening area of ​​the backflow wall that is swept over by the containers that can be attached to the pins. Preferably, the opening area is shaped like a possibly multiply coiled channel that follows the course of the U-shaped channel. Preferably, the openings are arranged in the backflow wall in an arrangement corresponding to the course of the U-shaped channel. Preferably, the shape of the opening area has a profile with at least one upper curved section, at least one lower curved section, and (between) at least one straight section that connects the upper curved section to the lower curved section. More preferably, the opening area has an opening area width that is less than or equal to the distance between the channel sidewalls.It is particularly preferred that the opening area width be essentially constant along the course of the opening area. In an advantageous embodiment, it is proposed that the at least one first flow guide device comprises at least one first deflecting element, which is arranged in the region of the open side of the U-shaped channel and connected to the U-shaped channel. Preferably, the first deflecting element has a deflecting surface that is inclined relative to a channel side wall of the U-shaped channel. Preferably, the at least one first deflecting element is formed with at least one deflecting plate or air guide plate. Preferably, the first deflecting element extends from an end of a channel side wall (facing the outflow chamber) towards or into the outflow chamber and / or towards the center of the U-shaped channel. More preferably, the first deflecting element extends from an end of a channel side wall (facing the outflow chamber) towards the return flow wall and towards the center of the U-shaped channel. Preferably, the at least one first deflection element is arranged and oriented such that it at least partially (but not completely) covers the U-shaped channel, in particular the open side of the U-shaped channel. Particularly preferably, the at least one first deflection element covers at least 5% or even at least 10% of a cross-sectional area (aligned parallel to the transport plane) of the U-shaped channel, in particular the open side of the U-shaped channel. According to an advantageous embodiment, it is proposed that the pin furnace further comprises at least: - at least one second flow guidance device, which is arranged in the inflow chamber and is designed and equipped to deflect the fluid. Preferably, the at least one second flow guide is arranged and oriented such that a fluid flow, in particular one generated by an impeller of the circulation device, is directed towards the U-shaped channel by means of the at least one second flow guide. More preferably, the at least one second flow guide surrounds the circulation device, in particular an impeller of the circulation device, at least partially. In an advantageous embodiment, it is proposed that the at least one second flow guide has a spiral housing for the recirculation device. In particular, the at least one second flow guide has a spiral impeller housing for the recirculation device. Preferably, the spiral (impeller) housing is arranged and / or held between an inner furnace wall and an (inlet) nozzle of the recirculation device. Furthermore, preferably, an outlet opening of the spiral (impeller) housing, from which the fluid or a fluid flow can be discharged, is oriented approximately vertically upwards and / or towards the U-shaped channel. In particular, the recirculation device is arranged below the course of the U-shaped channel. In a further advantageous embodiment, it is proposed that the at least one second flow guide device has at least one second deflection element in the area between the recirculation device and the U-shaped channel. Preferably, the at least one second deflection element is formed with at least one, and particularly preferably with at least two or even at least three, deflection plates or air guide plates. Furthermore preferably, the at least one second deflection element is held at a distance from one, and in particular from each, inner wall of the furnace in the inlet chamber. In an advantageous embodiment, it is proposed that the at least one second deflection element extends parallel to the transport plane, wherein the at least one second deflection element is at least inclined or curved towards the transport plane. Preferably, the at least one second deflection element is arranged at approximately the same height as the course of the U-shaped channel. In an advantageous embodiment, it is proposed that the pin furnace comprises a drying chamber and a heating chamber, which, when connected, form the furnace interior. The drying chamber has a height of 2 to 3 meters, particularly 2 to 2.6 meters or even 2 to 2.55 meters. Furthermore, the drying chamber preferably has an internal volume of 15 to 100 cubic meters, particularly 20 to 50 cubic meters or even 20 to 25 cubic meters. Such a low height and / or volume of the drying chamber can be achieved, in particular, by shortening the heating time of the container in the pin furnace. This can be achieved, in particular, by the fluid guidance provided by the first flow control device and / or the second flow control device.A correspondingly low height of the drying chamber, especially in combination with a correspondingly small volume, offers the particular advantage that the drying chamber can be transported in a standard container. This refers specifically to a drying chamber for a pin kiln with a capacity of at least 2,000 or even at least 2,400 containers per minute. A suitable standard container has the following internal dimensions: length: 12 m; width: 2.35 m; height: 2.69 m. Such a standard container is also known as a "40-foot HC (High Cube) container". Preferably, the pin furnace further comprises at least one heating device designed and configured to heat a fluid located in the furnace interior. Particularly preferably, the heating device comprises at least one heater that can be operated electrically and / or by means of fossil fuels. In particular, the heating device is formed with an oil burner or gas burner that burns into the furnace interior. Furthermore, an exhaust fan may be provided, preferably located in the exhaust chamber and / or fluidically connected to it. The exhaust fan may be located at least partially within the furnace interior and / or on the pin furnace. The exhaust fan serves, in particular, to extract fluid from the exhaust chamber. The exhaust fan can contribute to maintaining the driest possible atmosphere in the furnace interior, especially in the drying chamber area, for example, by removing fluid from the furnace interior that may be laden with liquid and / or contaminants, particularly after passing through the U-shaped channel. In particular, this should allow at least portions of the fluid to be removed that may be laden with condensate, water, solvent(s), and / or even a potentially flammable fluid. Regardless of the solution presented here, a pin furnace for drying a coating of at least one tubular container can contribute, in particular, to increasing the thermal and / or fluid-flow efficiency. The furnace comprises at least: - a furnace interior in which an approximately vertically oriented transport plane is arranged, wherein an inlet chamber and an outlet chamber are arranged upstream of the transport plane in the furnace interior; - at least one U-shaped channel running in the transport plane and open towards the outlet chamber; - a conveying device with a plurality of pins, wherein the pins each project at least partially into the U-shaped channel and are provided and configured to hold a tubular container; - at least one circulation device.which is at least partially located in the interior of the furnace and is designed and equipped to move a fluid located in the interior of the furnace; - at least one (second) flow guide device, which is located in the inlet chamber and is designed and equipped to deflect the fluid. It should be noted that the designations “first” and “second” flow guidance devices are only used to distinguish them from each other; therefore, “first” and / or “second” flow guidance devices can be provided independently of each other. The details, features, and advantageous designs discussed in connection with the previously presented pin furnace can also apply to the pin furnace presented here, and vice versa. In this respect, full reference is made to the explanations given there for a more detailed characterization of the features. The invention and its technical context are explained in more detail below with reference to the figures. It should be noted that the invention is not limited to the embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract aspects of the concepts illustrated in the figures and combine them with other components and / or findings from other figures and / or the present description. The figures schematically show: Fig. 1: a sectional view of a pin furnace, Fig. 2: a spiral housing, Fig. 3: a side view of a pin furnace, Fig. 4: a detail view of a U-shaped channel, Fig. 5: a detail view of another U-shaped channel, and Fig. 6: a detail view of a backflow baffle. Fig. 1 schematically shows a sectional view of a pin furnace 1 for drying a coating of at least one tubular container (not shown here). The pin furnace 1 has an interior chamber 3 in which an approximately vertically oriented transport plane 4 is arranged. The arrows shown in Fig. 1 illustrate how the fluid flow can circulate in the interior chamber 3. Upstream of the transport plane 4, an inlet chamber 5 and downstream of the transport plane 4, an outlet chamber 6 are arranged in the interior chamber 3. The pin furnace 1 also has a U-shaped channel 7 that runs in the transport plane 4 and is open towards the outlet chamber 6. Furthermore, the pin furnace 1 has, as shown in Fig.Figure 1 shows a conveying device 8 with a plurality of pins 9, a circulating device 10 which is at least partially arranged in the interior of the furnace 3, and a heating device 24 which is provided and configured for heating a fluid located in the interior of the furnace 3 and is shown here by way of example as a gas burner burning into the interior of the furnace 3. The arrows shown by way of example in Figure 1 also indicate how the circulating device 10 draws in the fluid heated by the heating device 24 and moves it in or through the interior of the furnace 3. Furthermore, Fig. 1 shows that the pin furnace 1 has a drying chamber 21 and a heating chamber 22, which, when connected (as shown here), form the furnace interior 3. Fig. 1 also illustrates that the drying chamber 21 has a drying chamber height 23. Fig. 1 also shows a second flow guide device 18, which is arranged in the inlet chamber 5 and is designed and configured to deflect the fluid. The second flow guide device 18 here has, by way of example, four second deflection elements 20, which are arranged in the area between the circulation device 10 and the U-shaped channel 7. The second deflection elements 20 are here, by way of example, formed with air guide vanes that extend parallel to the transport plane 4 (here into the plane of the drawing) and are curved towards the transport plane 4. Fig. 2 schematically shows a spiral-shaped housing 19 of the circulation device 10, which can have the second flow guide device 18 alternatively or cumulatively to the second deflection elements 20 shown in Fig. 1. Fig. 3 schematically shows a side view of a pin furnace 1. The pin furnace 1 shown here can be divided by way of example into a drying room 21, a heating room 22, a pre-drying frame 25 arranged upstream of the drying room 21 and a cooling zone 26 arranged downstream of the drying room 21. Fig. 4 schematically shows a detailed view of a U-shaped channel 7. The U-shaped channel 7 runs in the transport plane 4 and is open towards the outflow chamber 6. Towards the inflow chamber 5, the U-shaped channel 7 is closed by means of perforated, partially flowable channel walls. The fluid flow is also illustrated by arrows in Fig. 4. As shown in Fig. 4, a pin 9 of a conveying device 8 projects at least partially into the U-shaped channel 7. Furthermore, the pin 9 is designed and configured to hold a tubular container 2. The tubular container 2 is guided through the U-shaped channel 7 by the conveying device 8. Figure 4 also shows a first flow guide device 11, which is provided and configured to deflect the fluid in the region of an open side 12 of the U-shaped channel 7. The arrows in Figure 4 illustrate that the first flow guide device 11 is provided and configured to deflect at least a portion of the fluid flowing towards the open side 12 of the U-shaped channel 7 towards an end section 13 of the container 2 facing the outflow chamber 6. For this purpose, the first flow guide device 11 has, by way of example, a plurality of flowable openings 14, which are arranged in a backflow wall 15 located in the outflow chamber 6, wherein the openings 14 are arranged only in an opening area 16 of the backflow wall 15 that is swept over by the container 2. The backflow wall 15 is shown here in section. Fig. 5 schematically shows a detailed view of another U-shaped channel 7. Since the reference numerals are used consistently, we refer here to the preceding figure description with regard to the features already explained, which is hereby fully incorporated by reference. According to the illustration in Fig. 5, the first flow guide device 11 has two first deflection elements 17, which are arranged in the area of ​​the open side 12 of the U-shaped channel 7 and connected to the U-shaped channel 7. The first deflection elements 17 are shown here by way of example formed with air guide vanes. Furthermore, the first deflection elements 17 are arranged and oriented such that they partially cover the open side 12 of the U-shaped channel 7. Fig. 6 schematically shows a detailed view of a backflow wall 15. A plurality of flowable openings 14 of a first flow guide device 11 are formed in the backflow wall 15. Fig. 6 illustrates, from a different perspective than Fig. 4, that the openings 14 are arranged only in an opening area 16 of the backflow wall 15, which is swept over by the containers 2. For this purpose, the view in Fig. 6 is directed from the side towards the backflow wall 15. This document describes a pin oven for drying the coating of at least one tubular container, which at least partially solves the problems described with reference to the prior art. In particular, the pin oven allows for the most uniform possible heating of the container and the most uniform possible drying of the coating, while simultaneously minimizing the heating time or residence time of the container in the pin oven. Furthermore, the pin oven can be manufactured in a cost-effective and space-saving manner, is easy to transport, and can be operated in a resource-efficient and energy-efficient manner. In addition, the pin oven can exhibit a higher thermal and / or fluid-flow efficiency than conventional pin ovens. Reference symbol list 1 Pin furnace 2 Container 3 Furnace interior 4 Conveyor level 5 Inlet chamber 6 Outlet chamber 7 U-shaped channel 8 Conveyor device 9 Pin 10 Circulation device 11 First flow guide device 12 Open side 13 End section 14 Opening 15 Backflow wall 16 Opening area 17 First deflector 18 Second flow guide device 19 Housing 20 Second deflector 21 Drying chamber 22 Heating chamber 23 Drying chamber height 24 Heating device 25 Pre-drying frame 26 Cooling zone

Claims

Pin oven (1) for drying a coating of at least one tubular container (2), comprising at least: - an oven interior (3) in which an approximately vertically oriented transport plane (4) is arranged, wherein an inlet chamber (5) is arranged upstream of the transport plane (4) and an outlet chamber (6) is arranged downstream of the transport plane (4) in the oven interior (3), - at least one U-shaped channel (7) which runs in the transport plane (4) and has an open side (12) towards the outlet chamber (6), - a conveying device (8) with a plurality of pins (9), wherein the pins (9) each project at least partially into the U-shaped channel (7) and are provided and configured for holding a tubular container (2), - at least one circulation device (10) which is arranged at least partially in the oven interior (3) and is provided and configured for moving a fluid located in the oven interior (3),- at least one first flow guide device (11) which is provided and configured to deflect the fluid in the area of ​​the open side (12) of the U-shaped channel (7). Pin furnace according to claim 1, wherein the at least one first flow guidance device (11) is provided and arranged to direct at least one portion of the fluid flowing towards the open side (12) of the U-shaped channel (7) towards a container end section (13) of a container (2) that can be placed on one of the pins (9) facing the outflow chamber (6). Pin furnace according to claim 1 or 2, wherein the at least one first flow guide device (11) has a plurality of flowable openings (14) which are arranged in a backflow wall (15) arranged in the outflow chamber (6). Pin furnace according to claim 3, wherein the openings (14) are arranged only in an opening area (16) of the backflow wall (15) which is swept over by the containers (2) that can be placed on the pins (9). Pin furnace according to one of the preceding claims, wherein the at least one first flow guide device (11) has at least one first deflection element (17) which is arranged in the region of the open side (12) of the U-shaped channel (7) and is connected to the U-shaped channel (7). Pin furnace according to one of the preceding claims, further comprising at least: at least a second flow guide device (18) which is arranged in the inflow chamber (5) and is provided and equipped to deflect the fluid. Pin furnace according to claim 6, wherein the at least one second flow guide device (18) has a spiral housing (19) of the circulation device (10). Pin furnace according to claim 6 or 7, wherein the at least one second flow guide device (18) has at least one second deflecting element (20) in the area between the circulation device (10) and the U-shaped channel (7). Pin furnace according to claim 8, wherein the at least one second deflecting element (20) extends parallel to the transport plane (4) and wherein the at least one second deflecting element (20) is at least inclined or curved towards the transport plane (4). Pin furnace according to one of the preceding claims, wherein the pin furnace (1) has a drying chamber (21) and a heating chamber (22) which, when connected, form the furnace interior (3), wherein the drying chamber (21) has a drying chamber height (23) in the range of 2 to 3 m.

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