Device for metering a cryogenic medium

Abstract

In order to cool products, the process of metering a cryogenic medium, for example liquid nitrogen, liquid oxygen or liquid carbon dioxide, into a container containing the product is known. The cryogenic medium is introduced by means of a device having a valve which is mounted in the wall of the container and is connected to a supply line for the cryogenic medium. The valve is equipped with a valve housing in which a shut-off element is received, the shut-off element being brought from a closed position into an open position in the axial direction against the effect of a restoring spring by means of an electromagnet, the cryogenic medium being able to flow into the container at a nozzle opening in the open position. According to the invention, when the valve is opened, an annular gap opens through which the cryogenic medium is distributed over the interior of the container.

Description

[0001] MG 24330 05.09.2024

[0002] -1-

[0003] Device for dosing a cryogenic medium

[0004] The invention relates to a device for dosing a cryogenic medium into a container, comprising a valve which has a valve housing that can be attached to a wall of the container, which is equipped with a connection for connecting a supply line for supplying a cryogenic medium into the valve housing and with an annular nozzle opening for introducing the cryogenic medium from the valve housing into the container and in which a shut-off element is axially movable in such a way that it can be moved from a closed position, in which the shut-off element closes the nozzle opening, against the action of a restoring spring element into an open position, in which the shut-off element is positioned opposite the nozzle opening and thus releases it.

[0005] In many industrial applications, cryogenic media, especially cryogenic liquids or gases, are used to cool or freeze liquid, pasty, or solid products. Heat transfer occurs either indirectly, without physical contact between the product to be cooled and the cryogenic medium via heat exchanger surfaces, or through direct contact of the product with the cryogenic medium. In the latter case, the product to be cooled is typically conveyed through a pipe or collected in a container, and the cryogenic medium is introduced into the pipe or container via suitable nozzles, valves, or other metering devices.

[0006] If the product to be cooled is in a container, such as a mixer, several options are available for introducing the cryogenic medium: When introduced into the headspace of the container, the inlet points for the cryogenic medium have little or no contact with the product being cooled. Since there is a certain distance between the product and the inlet points, the risk of icing at the inlet points is low. Therefore, simple valves or nozzles can be used – for example, spray nozzles or capillary nozzles that are always open to the interior of the container. A disadvantage of this is [MG 24330 05.09.2024].

[0007] -2-

[0008] However, the problem with these systems is that only a portion of the cryogenic medium comes into contact with the product and can extract heat from it, while the remaining, often larger, portion escapes unused into the atmosphere or is carried away via a duct.

[0009] To improve the transfer of heat energy to the cryogenic medium, the cryogenic medium is alternatively injected directly into the product. For this method, the inlet points for the cryogenic medium are not located in the headspace, but rather in a lower part of the container, i.e., in the area filled with the product to be cooled during treatment. With this procedure, also known in technical jargon as "bottom injection," it is crucial to ensure that the valve can always be closed to prevent the inlet points from freezing during treatment and thus becoming blocked or impairing their functionality. Furthermore, it must be prevented that product penetrates the interior of the nozzle and accumulates there permanently, which would pose a risk of contamination. The issues discussed here also apply, analogously, to the injection of a coolant into a line through which a liquid product flows.

[0010] A valve suitable for use in bottom injection for introducing a cryogenic medium is described in DE 101 52 764 A1. The valve comprises a valve housing integrated into the wall of a container, such as a mixer. A tubular valve opening with a small cross-sectional area is arranged in the valve housing and can be closed by means of a valve needle. This arrangement is disadvantageous in that the cryogenic medium is introduced into the container in the form of a compact jet, which can lead to localized subcooling of the product and, overall, to unsatisfactory inhomogeneous cooling of the product.

[0011] From EP 1 867 902 A2 and EP 2 309 160 A1, devices for metering a cryogenic medium into a container are known, which are equipped with a valve in which a piston-shaped shut-off element equipped with a closing plate is located in a guide channel against the action of a MG 24330 05.09.2024

[0012] -3-

[0013] The valve is arranged with limited movement thanks to a spring. The guide channel of the shut-off element, which opens into the container at a nozzle opening, simultaneously serves as a flow channel for the cryogenic medium. If the pressure in the supply line for the cryogenic medium exceeds a certain limit determined by the spring force, the shut-off element, along with the closing plate, is pushed towards the interior of the container, thus opening the valve. When the pressure in the coolant supply line decreases, the shut-off element automatically returns to its closed position under the action of the spring and due to the pressure inside the container, in which the closing plate seals against the nozzle opening.

[0014] However, a problem with these items is that the movement of the sealing plate into the container can obstruct the movement of any agitator or similar device located there, and there is also the risk of product accumulating between the sealing plate and the container wall, which impairs the functionality of the valve.

[0015] The object of the present invention is therefore to create a device for dosing a cryogenic medium which is simple in design and suitable for bottom injection and which overcomes the disadvantages of the prior art.

[0016] This problem is solved by a device having the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

[0017] According to the invention, a device of the type and purpose mentioned above is characterized in that the shut-off element is equipped with an annular sealing section which, in the closed position of the shut-off element, closes the annular nozzle opening from the side opposite the container in the installed state, and that the shut-off element is retracted into the interior of the valve housing during its movement from the closed position to the open position, thereby releasing the nozzle opening. MG 24330 05.09.2024

[0018] -4-

[0019] According to the invention, the valve is designed such that the shut-off element retracts into the interior of the valve housing when changing from the closed to the open position. It therefore moves away from the interior of the container and does not protrude into it. Various actuators can be used to open the valve, for example, an electromagnet that interacts with a ferromagnetic part of the shut-off element and exerts a force on it opposite to the force of the return spring, or a pneumatic or electric drive motor. Alternatively or additionally to the aforementioned actuators, the pressure of the cryogenic medium inside the valve housing can also be used to move the shut-off element into its open position, the force of which exceeds the force of the return spring.After the valve opens, the cryogenic medium flows through the interior of the valve housing, past the retracted shut-off element, and into the container via the nozzle opening. The annular shape of the nozzle opening also ensures that the cryogenic medium is not introduced into the container as a compact jet, but rather spreads out broadly within the container.

[0020] In the context of the invention, the term "container" is understood to mean a container filled with a product to be cooled or a pipeline through which such a product flows. Containers of this type are used, for example, in the food or pharmaceutical industries for the batch production or processing of a product or intermediate product; for example, a mixer or a tumbler. To carry out the aforementioned "bottom injection," the device according to the invention is preferably arranged in a region of the container that, during normal use, is wetted by a product contained in the container, so that the cooling medium is introduced directly into the product and thus thoroughly mixed with it. The term "pipeline" can also refer to a pressure line through which a liquid to be treated flows.

[0021] Preferably, the valve is designed such that the nozzle opening faces the

[0022] Introducing the cryogenic medium into the container through an annular gap formed MG 24330 05.09.2024

[0023] -5- is bounded externally by a wall of the valve housing and internally by a flow element projecting inside the valve housing, which is rigidly connected to the valve housing. The shut-off element is axially movable and radially outside the flow element inside the valve housing and is equipped on one end face with an annular sealing section, which, in the closed position, closes the annular nozzle opening of the shut-off element from the side opposite the container, but, in the open position, is retracted into the interior of the valve body at a distance from this side.

[0024] An advantageous embodiment of the invention provides that the sealing section of the shut-off element and / or the flow element is / are each equipped with a front surface which, when the valve is installed and in its closed state, is flush with an inner surface of the container. This ensures that, during operation of the device, no parts of the device protrude inside the container or that there are no dead spaces in which product from the container can accumulate.

[0025] A further advantageous embodiment of the invention provides that the flow body has a front section which is conical and widens towards the interior of the container when the device is installed. Due to the narrowing flow cross-section between the wall of the valve body and the flow body, the cryogenic medium flowing through the valve body is accelerated and simultaneously deflected radially by the conical front section, thus distributing it broadly within the container. This prevents localized subcooling of the product inside the container.

[0026] Preferably, the shut-off element consists at least partially of ferromagnetic material and interacts with an electromagnet arranged inside or outside the valve housing to move it into its open position. The axial movement of the shut-off element into its open position is thus counteracted by the force of the return spring by the actuation of an electromagnet. MG 24330 05.09.2024

[0027] -6-

[0028] An electromagnet is located either on the outside of the valve housing, i.e., without direct contact with the cryogenic medium, or inside it. For this purpose, the entire shut-off element, or at least a portion of it, is constructed from a ferromagnetic material, such as ferromagnetic, cold-resistant steel. Once the shut-off element is moved into its open position, the nozzle opening is released, and the cryogenic medium, supplied via the feeder, can flow into the container. After the magnetic field is switched off, the shut-off element automatically returns to its closed position under the action of the return spring. In a particularly compact design, the electromagnet is configured as a tubular solenoid, within whose tubular interior at least part of the valve housing is enclosed.

[0029] Advantageously, the valve housing is permanently but detachably connected to the container wall. This can be achieved, for example, by screwing it into a threaded opening in the container wall. A particularly advantageous embodiment of the invention, especially for the food industry, provides that the valve housing is connected to the container via a connecting piece, which in turn is permanently connected to the container wall, for example, by welding. The valve housing, with its front section containing the nozzle opening, is inserted into the connecting piece and detachably connected to it at the end of the connecting piece facing away from the container, for example, by means of a clamping flange connection or, in the manner of an Ingold fitting, by means of a union nut.Preferably, a suitable sealing element, such as a gasket, arranged between the inner surface of the connecting nozzle and the inserted front section ensures that as little product as possible from the interior of the container can penetrate into the annular gap between the connecting nozzle and the front section.

[0030] A further advantageous embodiment of the device according to the invention provides means for regulating the flow rate of cryogenic medium supplied to the container via the valve. These means can, for example, be an electronically controlled valve in the supply line. MG 24330 05.09.2024

[0031] -7- act and / or the aforementioned electromagnet can be electronically actuated. The valve and / or magnet are in data communication with an electronic control unit, which regulates the supplied flow rate of cryogenic medium depending on a predefined program and / or depending on parameters measured by sensors also connected to the control unit, such as the temperature in the container.

[0032] A preferred cryogenic medium is a liquefied medium, such as liquid nitrogen, liquid oxygen, liquid nitrous oxide (NO2), or liquid carbon dioxide, or a cold gas, for example, cryogenic gaseous nitrogen, oxygen, nitrous oxide, or a noble gas such as argon, or a mixture of the aforementioned gases. In general, the device according to the invention can be used to dose a gas or a liquid into a gas, a liquid, or into a pasty, powdery, or lumpy substance.

[0033] The drawings will be used to explain an embodiment of the invention in more detail. The schematic views show:

[0034] Fig. 1: A device according to the invention, installed in a container, in its closed state in longitudinal section.

[0035] Fig. 2: The device from Fig. 1 in its open state.

[0036] The device 1 shown in the drawings has a valve 2 mounted on a container 3, such as a vessel intended for holding a product to be cooled, such as a mixer, or a fluid-carrying pipeline. The valve 2 has a substantially cylindrical valve housing 4, which is mounted on a wall 5 of the container 3. In the embodiment shown here, a connecting nozzle 6 with a connecting flange 7 is arranged at an opening in the wall 5, for example, welded on. A ring flange 8 is arranged radially on the outside of the valve housing 4, for example, also welded on or formed integrally with the valve housing 4. The valve housing 4 is connected to a front section in MG 24330 05.09.2024

[0037] -8- the connecting piece 6 is inserted, and the connecting flange 7 and the ring flange 8 are firmly but detachably connected to each other by means of a clamping ring 10. The front section 9 of the valve housing 4 should be dimensioned such that, as shown here, its front surface is flush with an inner surface 11 of the wall 5.

[0038] Instead of the connecting means shown here for attaching the valve housing 4 to the container 3, other means not shown here can also be used, such as a screw connection or a fastening by means of a union nut pushed over a rear section of the valve housing 4, which interacts with a thread in the connecting nozzle 6 in the manner of an Ingold nozzle.

[0039] A supply line 12 for a cryogenic medium, such as liquid nitrogen or liquid carbon dioxide, opens into a side wall of the valve housing 4. The supply line 12 is detachably connected to the valve housing 4 in a manner not shown here, for example by means of a screw or flange connection; the type of connection is adapted to the cryogenic medium used and is designed to withstand pressure and / or low temperatures as needed. The supply line 12 can be opened and closed by means of a valve 13.

[0040] The front section 9 of the valve housing 4 is open towards the interior of the container 3. A flow element 15 is arranged inside the valve housing 4, preferably rotationally symmetrical about an axis 14 of the valve housing 4. The flow element 15 is fixedly connected to the valve housing 4 at a rear mounting section 16 and projects into the valve housing 4 with a front section 17 up to the front edge of the front section 9 of the valve housing 4, leaving an annular gap 18 between the front section 17 and the valve housing 4. In the embodiment shown here, the front section 17 is conical and widens towards the container 3, so that the free flow cross-section between the flow element 15 and the wall of the valve housing 4 decreases continuously towards the container 3. MG 24330 05.09.2024

[0041] -9-

[0042] Inside the valve housing 4, a shut-off element 20 is axially movably mounted, by means of which the valve 2 can be opened and closed. The shut-off element 20 consists of a sealing section 21, a retaining section 22, and a rear section 23. In the closed state of the valve 2 shown in Fig. 1, the annular sealing section 21 is pressed between the flow element 15 and the wall of the valve housing 4, thereby completely sealing the annular gap 18. For this purpose, the sealing section 21 is equipped with a seal 24 made of a material that remains flexible at low temperatures, such as Teflon.

[0043] The cylindrical rear section 23 is arranged on the side of the mounting section 16 facing away from the container 3 and, in the embodiment shown here, consists at least partially of a ferromagnetic material. The rear section 23 also forms a spring seat for a return spring 25, which is clamped in the valve housing 4 between the rear section 23 and a rear wall 26 of the valve housing 4.

[0044] The retaining section 22, which connects the sealing section 21 to the rear section 23, extends radially on the outside of the flow body 15 and is guided through corresponding bores 27 in the mounting section 16 by a plurality of connecting elements 27a, 27b. The connecting elements 27a, 27b and the bores are designed such that the retaining section 22, and thus the entire shut-off element 20, is freely movable in the axial direction, but is limited by the sealing section 21, which interacts with the front section 17 of the flow body, on the one hand, and by the rear section 23, which interacts with the mounting section 16 and the return spring 25, on the other. Furthermore, the retaining section 2 has flow openings 28 that allow the flow of cryogenic medium.

[0045] Radially on the outside of the valve housing 4 is located as shown here.

[0046] Exemplary embodiment a tubular electromagnet 29 which covers the entire

[0047] Rear section of the valve housing 4, below the mounting section 15 MG 24330 05.09.2024

[0048] -10- encloses. The electromagnet 29 serves to actuate the valve 2 in the manner described below.

[0049] Without actuation of the electromagnet 29, i.e. without an acting magnetic field, the valve 2 is in its closed state shown in Fig. 1, i.e. the shut-off element 20 is pressed against the annular gap 18 with its sealing section 21 due to the force of the return spring 25.

[0050] To open the valve 2, the electromagnet 29 is actuated. This generates a magnetic field inside the valve housing 4, which exerts a force on the rear section 23 that opposes the force of the return spring 25. If the magnetic force of the electromagnet 29 exceeds the spring force, the shut-off element 20 moves towards the rear wall 26 of the valve housing 4 into its open position shown in Fig. 2, thus releasing the annular gap 18. In this open state of the valve 2, the cryogenic medium supplied via the feed line 12 can flow through the valve housing 4, past the retaining section 22 and the sealing section 21, into the interior of the container 3.The conically outward-facing surface of the front section 17 of the flow element 15 directs the incoming cryogenic medium radially outwards, causing it to spread widely inside the container 3 and / or mix thoroughly with any product to be cooled located within the container 3. The shut-off element 20 therefore does not move into the interior of the container, thus ensuring that the movement of any agitator or similar device located inside the container 3 is not impaired. After the electromagnet 23 is switched off, the shut-off element 20 automatically returns to its closed position due to the action of the return spring 25.

[0051] To counter the risk of material from inside the container 3 penetrating the space between the valve housing 4 and the connection nozzle 6 during operation of the device 1, a seal 30 made of a low-temperature resistant material can be provided there. MG 24330 05.09.2024

[0052] -11-

[0053] Valve 2 is actuated by means of an electronic control unit (not shown here) which, for example, controls the flow of the cryogenic medium via the supply line 12 through the valve 13 and / or the actuation of the electromagnet 29. Preferably, the flow is regulated as a function of a parameter measured by sensors (also not shown here), such as the temperature or viscosity of a product in the container 3.

[0054] The valve body 4, the shut-off element 20 and the return spring 25 are made of a material that takes into account the low temperatures and / or high pressures of the respective cryogenic medium used, for example a suitable, low-temperature resistant stainless steel.

[0055] Device 1 particularly meets the stringent hygiene requirements for the production or processing of foodstuffs such as dough, flour, mash, or meat mixture for sausage production, or for the production or processing of pharmaceutical products, intermediate products, or ingredients. Another area of ​​application involves the dosing of a cryogenic medium into a line through which a gas or liquid flows, for example, in wastewater treatment or the treatment of wine, juices, or milk.

[0056] MG 24330 05.09.2024

[0057] -12-

[0058] Reference symbol list

[0059] 1 Device 16 Mounting section

[0060] 2 Valve 17 Front section

[0061] 3 Container 18 Annular gap

[0062] 4 Valve housings 19

[0063] 5 wall 20 shut-off valve

[0064] 6 connection spigots 21 sealing section

[0065] 7 Connecting flange 22 Holding section

[0066] 8 Ring flange 23 Rear section

[0067] 9 Front section 24 Seal

[0068] 10 Clamping ring 25 Return spring

[0069] 11 Interior surface 26 Back panel

[0070] 12 Supply line 27a, 27b Connecting element

[0071] 13 valves, 28 flow openings

[0072] 14 Axis 29 Electromagnet

[0073] 15 Flow elements 30 Seals

Claims

MG 24330 05.09.2024 -13- Patent claims 1. Device for metering a cryogenic medium into a container (3), comprising a valve (2) which has a valve housing (4) attachable to a wall (5) of the container (3), which is equipped with a connection for connecting a supply line (12) for supplying a cryogenic medium into the valve housing (4) and with an annular nozzle opening (18) for introducing the cryogenic medium from the valve housing (4) into the container (3), and in which a shut-off element (20) is axially movably mounted such that it can be moved from a closed position, in which the shut-off element (20) closes the nozzle opening (18), against the action of a restoring spring element (25), to an open position, in which the shut-off element (20) is positioned opposite the nozzle opening (18) and thus releases it, characterized in that the shut-off element (20) is equipped with a is equipped with an annular sealing section (21 ).which, in the closed position of the shut-off element (20), closes the annular nozzle opening (18) from the side opposite the container (3) in the installed state, and that the shut-off element (20) is retracted into the interior of the valve housing (4) during its movement from the closed position to the open position, releasing the nozzle opening (18).

2. Device according to claim 1, characterized in that the annular nozzle opening (18) is bounded by an inner surface of the outer wall of the valve housing (4) and by a flow body (15) which is fixedly connected to the valve housing (4) and projects inside the valve housing (4), and the shut-off element (20) extends radially on the outside of the flow body (15).

3. Device according to claim 1 or 2, characterized in that the sealing section (21) of the shut-off member (20) and / or the flow body (15) each has an outer surface which, in the installed state of the MG 24330 05.09.2024 -14- Device (1) , in the closed position of the shut-off element (20) run flush with an inner surface (11) of the container (3).

4. Device according to one of the preceding claims, characterized in that the flow body (15) is equipped with a conical front section (17) which widens towards the interior of the container (3) when the device (1) is installed.

5. Device according to one of the preceding claims, characterized in that the shut-off element (20) is at least partially made of ferromagnetic material and cooperates with an electromagnet (29) arranged inside or outside the valve housing (4) to move it into its open position.

6. Device according to one of the preceding claims, wherein the valve housing (4) is fixedly but detachably connected to the wall (5) or to a connection fitting (6) fixedly mounted on the wall (5) of the container (3), for example an Ingold fitting or a connection flange.

7. Device according to one of the preceding claims, characterized in that the valve (2) is provided with means for regulating the flow rate of cryogenic medium supplied to the container (3).

8. Device according to one of the preceding claims, characterized in that liquid or gaseous nitrogen, liquid or carbon dioxide, liquid or gaseous oxygen, liquid or gaseous nitrous oxide, a liquid or gaseous noble gas or a mixture of these gases is used as the cryogenic medium.

Images