Pressing apparatus and related methods

Abstract

A press apparatus (100) is disclosed, comprising a pressure vessel (1) having an internal space (5), an inlet (7) and an outlet (8) in fluid communication with the internal space (5), and at least one pressure medium guide channel (6) extending between the inlet (7) and the outlet (8). The press apparatus (100) comprises a cooling unit (20) located downstream of the inlet and configured to cool the pressure medium being guided through the at least one pressure medium guide channel (6). At least one (14) pressure medium flow generators located downstream of the cooling unit (20) are configured to receive the flow of pressure medium cooled by the cooling unit (20) so that the temperature of the pressure medium does not exceed a first selected temperature, and to generate a flow of pressure medium in the at least one pressure medium guide channel (6) toward the outlet (8). Related methods are also disclosed.

Description

Technical Field

[0001] The present invention relates to a pressing device including a pressure vessel having an internal space and arranged to hold a pressure medium in the internal space during use of the pressing device. The pressing device can be configured to process at least one article, for example, by isostatic pressurization.

Background Art

[0002] Articles subjected to isostatic pressurization, such as cold isostatic pressurization (CIP), warm isostatic pressurization (WIP), high-pressure pressurization (HPP), or hot isostatic pressurization (HIP), are generally positioned in a pressure vessel arranged to hold a pressure medium within it. The processing cycle may comprise loading the articles into the pressure vessel, closing and sealing the pressure vessel, processing the articles within the pressure vessel, opening the pressure vessel, and removing the articles from the pressure vessel. Several articles may be processed simultaneously. The processing cycle may be divided into several parts or stages. After loading the articles into the pressure vessel, the pressure vessel may then be sealed, and subsequently, a pressure medium (e.g., a gas or a fluid such as water or oil) may be introduced into the pressure vessel so that the pressure inside the vessel rises to a certain pressure level; this may be called the pressurization stage, in which case the articles may be subjected to the increased pressure for a selected period of time. The processing cycle may comprise a heating stage, in which the pressure medium is heated, for example, to achieve its desired or required temperature. The heating stage may be carried out concurrently with the pressurizing stage, before the pressurizing stage, or after the pressurizing stage. Exposing the articles to the increased pressure inside the pressure vessel for a selected period of time may be called the pressing stage, or holding stage, of the processing cycle. After the pressing stage, and before opening the pressure vessel to remove the articles, the pressure inside the pressure vessel is generally reduced to a sufficiently low level by drawing the pressure medium out of the pressure vessel. This may be called the pressure reduction stage or pressure relief stage. The processing cycle may further comprise a cooling stage. However, depending on the type of isotropic press used (e.g., whether the isotropic press is configured to perform CIP, WIP, HPP, or HIP), the cooling stage is not always necessary. [Overview of the Initiative]

[0003] Once the desired or required pressure in the pressure vessel and the desired or required temperature of the pressure medium are achieved, it may be desirable to maintain the pressure and temperature of the pressure medium in the pressure vessel over a long period of time. A long period of time may be, for example, the duration of the pressing phase of a processing cycle or substantially the entire duration. The inventors have found that it may be beneficial to generate and / or maintain circulation of the pressure medium within the pressure vessel over a long period of time to ensure that the temperature of the pressure medium is uniform throughout the pressure vessel—or at least throughout (or substantially throughout) the entire space within the pressure vessel in which at least one article to be processed is held. The space within the pressure vessel in which at least one article to be processed is held may be called the internal space and may be defined, for example, by a loading compartment. If there is no circulation of the pressure medium within the pressure vessel for such a long period of time, temperature stratification may occur within the pressure vessel, resulting in different temperatures of the pressure medium in different parts of the pressure vessel. This can lead to an uneven temperature distribution in at least one article being processed, or to different temperatures between different articles or components being processed within the pressure vessel. This can result in the properties of at least one processed article not meeting the intended specifications of the processed article and / or different processing conditions for different articles, which can be undesirable in many applications as it can lead to different results from processing different articles. One example of such an application may be the processing of solid-state battery (SSB) components, i.e., at least one article comprising, composed of, or based on one or more SSB components, e.g., all-solid-state battery (ASSB) components, or semi-solid-state battery components.For example, reducing or avoiding temperature variations within different parts of at least one processed article at the end of the pressing stage of the processing cycle may help reduce or avoid internal stress in the processed article(s) during the subsequent cooling stage of the processing cycle, and may also provide an efficient method for obtaining articles(s) or components(s) with uniform material properties and density while minimizing internal voids and defects without geometric distortion of the article(s) or components(s). For example, in SSB applications, the inventors have found that relatively high uniformity in density and other material properties of SSB components(s) provides an increased yield from processing a large number of SSB components and can improve the material properties of the processed product, including material properties such as porosity (e.g., porosity of anode, cathode, electrolyte, cathode liquid and / or anode liquid (composite) materials) and (e.g., volume) energy density, as well as the electrical and electrochemical properties and capacity of battery cells(s). By reducing the porosity of articles such as SSB components, the volume expansion of SSB components during SSB charging can be reduced, which in turn can increase the lifespan of the SSB.

[0004] In consideration of the foregoing, the object of the present invention is to provide a press apparatus comprising a pressure vessel having an internal space and arranged to hold a pressure medium within the internal space during use of the press apparatus, the press apparatus being configured to process at least one article and capable of reducing, or even avoiding, any non-uniformity of the temperature distribution in the at least one article being processed.

[0005] To address this concern and at least one of the other concerns, a pressing apparatus and a method in a pressing apparatus are provided according to the independent claim. Embodiments of the present invention are defined by the dependent claims.

[0006] According to a first aspect of the present invention, a press apparatus is provided. The press apparatus comprises a pressure vessel having an internal space. The pressure vessel is arranged to hold a pressure medium in the internal space during use of the press apparatus. The press apparatus comprises at least one pressure medium guide path. The at least one pressure medium guide path has an inlet and an outlet, extends between the inlet and the outlet, and these inlet and outlet are in fluid communication with the internal space. The at least one pressure medium guide path is configured to guide the pressure medium from the inlet to the outlet. The press apparatus comprises at least one pressure medium flow generator, which is configured to generate a flow of pressure medium that enters the inlet, passes through the at least one pressure medium guide path, and exits the outlet. The press apparatus comprises a cooling unit, which is located downstream of the inlet and is configured to cool the pressure medium being guided through the at least one pressure medium guide path. At least one of the at least one pressure medium flow generator is located downstream of the cooling unit and is configured to receive the flow of pressure medium cooled by the cooling unit and generate a flow of pressure medium in the at least one pressure medium guide path toward the outlet. The cooling unit is configured to cool the pressure medium being guided through at least one pressure medium guide path such that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a first selected temperature.

[0007] A second aspect of the present invention provides a method in a press apparatus. The press apparatus comprises a pressure vessel having an internal space. The pressure vessel is arranged to hold a pressure medium in the internal space during use of the press apparatus. The press apparatus comprises at least one pressure medium guide path. The at least one pressure medium guide path has an inlet and an outlet, extends between the inlet and the outlet, and these inlet and outlet are in fluid communication with the internal space. The at least one pressure medium guide path is configured to guide the pressure medium from the inlet to the outlet. The press apparatus comprises at least one pressure medium flow generator, which is configured to controllly generate a flow of pressure medium entering the inlet, passing through the at least one pressure medium guide path, and exiting the outlet. The press apparatus comprises a cooling unit, which is located downstream of the inlet, and is configured to controllly cool the pressure medium being guided through the at least one pressure medium guide path. The method comprises controlling the at least one pressure medium flow generator to generate a flow of pressure medium entering the inlet and toward the cooling unit. At least one of the at least one pressure medium flow generators is located downstream of the cooling unit and is configured to receive a flow of pressure medium cooled by the cooling unit. The method further comprises controlling at least one of the at least one pressure medium flow generators to generate a flow of pressure medium in at least one pressure medium guideway toward an outlet. The method further comprises controlling the cooling unit to cool the pressure medium being guided through at least one pressure medium guideway such that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a first selected temperature.

[0008] By providing at least one pressure medium flow path and at least one pressure medium flow generator, it may be made easier or possible to generate and / or maintain circulation of the pressure medium within the pressure vessel, for example, over a long period of time. In particular, circulation of the pressure medium within the internal space and loading compartment may be generated and / or maintained, for example, over a long period of time. As stated above, generating and / or maintaining such circulation of the pressure medium may be advantageous in reducing or even avoiding any non-uniformity of the temperature distribution in at least one article when at least one article is processed by the press device during the use of the press device. If there is no circulation of the pressure medium within the pressure vessel during the pressing phase of the processing cycle, the temperature of the pressure medium may differ between different parts of the pressure vessel, which may lead to a non-uniform temperature distribution in at least one article, for example, during the pressing phase or at least at the end of the pressing phase, or to different temperatures between different articles or components processed within the pressure vessel. As stated above, this may be undesirable in many applications, such as in the processing of SSB components. For example, reducing or avoiding temperature variations within different parts of at least one processed article at the end of the pressing stage of the processing cycle may help reduce or avoid internal stresses in the processed article(s) during the subsequent cooling stage of the processing cycle, and may also provide an efficient method for obtaining articles(s) or components(s) with relatively high uniformity of density and other material properties, while minimizing internal voids and defects, without geometric distortion of the article(s) or components(s).

[0009] Reducing or avoiding temperature variations within different parts of at least one processed article, or between different articles or components processed in a pressure vessel, may be particularly beneficial, as described above, during the pressing stage or at least at the end of the pressing stage, i.e., during or at least at the end of the time period in which at least one article is exposed to the increased pressure in the pressure vessel. The pressing stage may also be called the holding stage. However, reducing or avoiding temperature variations within different parts of at least one processed article, or between different articles or components processed in a pressure vessel, may also be beneficial in other stages of the processing cycle, for example, during the heating stage in which the pressure medium is heated, in order to keep the time required to carry out the processing cycle relatively short, for example, in order to achieve the desired or required temperature of the pressure medium.

[0010] In SSB components, such as ASSB components, there are generally various solid elements that can exhibit diverse or different chemical, physical, and / or mechanical properties. Therefore, and furthermore, due to the nature of the bonding between such solid elements, a relatively large number of internal interfaces can exist within the SSB component. In the processing of SSB components, such as ASSB components, reducing or avoiding temperature variations within different parts of the SSB component can help achieve uniform densification across the internal interfaces of the SSB component and uniform densification of the solid electrolyte within the SSB component. It can also be beneficial in inducing desired chemical and electrochemical reactions (e.g., solid electrolyte interphase formation) at the internal interfaces of the SSB component. Furthermore, internal interfaces within the SSB / ASSB (e.g., between the current collector anode and the anode composite, between the cathode current collector and the cathode composite, between the cathode and the solid electrolyte (SSE), and between the anode and the SSE) can be strengthened and stabilized.

[0011] As is known in the art of isotropic pressurization, at least one article to be processed may be placed in a bag or pouch before processing. Any warping or distortion of the bag or pouch may be reduced or even eliminated by reducing or avoiding temperature variations within different parts of at least one processed article.

[0012] The pressure medium may comprise a fluid, such as a liquid and / or a gas. The fluid may comprise, for example, water, and / or oil, and / or another suitable liquid. The oil may comprise, for example, mineral oil. The gas may comprise, for example, an inert gas such as argon gas.

[0013] A pressure vessel may have, for example, a cylindrical shape. However, while a cylindrical shape may be preferred for a pressure vessel, it may also have a shape other than a cylinder.

[0014] When in use, the pressure vessel may be positioned such that, for example, its longitudinal axis is oriented perpendicular or substantially perpendicular to a vertical line (e.g., a plumb line), or parallel or substantially parallel to a vertical line (e.g., a plumb line).

[0015] A press device may be configured to process at least one article by isostatic pressing. Processing by isostatic pressing facilitates or enables achieving the same material properties for all articles processed by the press device. For example, a press device may be configured to process at least one article by at least one of cold isostatic pressing (CIP), warm isostatic pressing (WIP), high-pressure pressing (HPP), or hot isostatic pressing (HIP).

[0016] In general, CIP processing may involve temperatures within the pressure vessel, such as (for example) 50°C or less, for example, within the range of (for example) room temperature (for example) (e.g., 20°C) to (for example) 50°C. Furthermore, CIP processing may involve pressures within the pressure vessel, such as (for example) 50 MPa to (for example) 600 MPa, depending on the material of the item(s) being processed and the temperature within the pressure vessel, for example, within the range of (for example) 50 MPa to (for example) 1600 MPa.

[0017] Generally, WIP processing may involve temperatures within a pressure vessel, such as (for example) 50°C to (for example) 400°C. Furthermore, WIP processing may involve pressures within a pressure vessel, such as (for example) 50 MPa to (for example) 600 MPa, or (for example) 1600 MPa, depending on the material of the item(s) being processed and the temperature within the pressure vessel.

[0018] In general, HIP treatment may involve temperatures within the pressure vessel, such as (for example) 400°C or higher, for example, in the range of (for example) 400°C to (for example) 2500°C. Furthermore, HIP treatment may involve pressures within the pressure vessel, such as (for example) 50 MPa to (for example) 210 MPa, for example, in the range of (for example) 50 MPa to (for example) 300 MPa, depending on the material of the item(s) being treated and the temperature within the pressure vessel.

[0019] Generally, HPP treatment may involve temperatures within the pressure vessel that are (for example) above 0°C, for example, in the range of (for example) 0°C to (for example) 100°C, and typically in the range of (for example) 4°C to (for example) 40°C. Furthermore, HPP treatment may involve pressures within the pressure vessel that are (for example) in the range of (for example) 100 MPa to (for example) 800 MPa, generally in the range of (for example) 400 MPa to (for example) 600 MPa, depending on the material of the item being treated and the temperature within the pressure vessel.

[0020] "Use of a press device" can, in principle, refer to any use of a press device in connection with the processing of at least one article. For example, a pressure vessel may be positioned to hold a pressure medium within its internal space during the pressurizing, heating, pressing, and / or other stages of a processing cycle, as previously described. Thus, "use of a press device" can refer to, for example, one or more of pressurizing, heating, pressing, or cooling, or any combination of such stages and any other possible stages of a processing cycle.

[0021] As described above, the press apparatus includes a cooling unit located downstream of the inlet and configured to cool the pressure medium being guided through at least one pressure medium guide channel, and at least one of at least one pressure medium flow generators located downstream of the cooling unit and configured to receive the flow of pressure medium cooled by the cooling unit and generate a flow of pressure medium in at least one pressure medium guide channel toward the outlet. The cooling unit is configured to cool the pressure medium being guided through at least one pressure medium guide channel such that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a first selected temperature. Such a configuration may be particularly advantageous if the at least one pressure medium flow generator located downstream of the cooling unit is of a type or configuration that may not function or operate properly, or may even malfunction, when the temperature of the pressure medium received by the pressure medium flow generator(s) is relatively high. During use of the press apparatus, the temperature of the pressure medium can become relatively high. As described above, the press apparatus may be configured to process at least one article by isotropic pressure, in which case the temperature of the pressure medium may be relatively high. If the temperature of the pressure medium induced in at least one pressure medium flow path becomes too high for at least one of the at least one pressure medium flow generators located downstream of the cooling unit to function or operate properly, the cooling unit may cool the pressure medium induced in at least one pressure medium flow path so that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a temperature at which it or those pressure medium flow generators may not function or operate properly, or may even malfunction.

[0022] For example, at least one of the at least one pressure medium flow generators may be associated with a nominal maximum pressure medium temperature, which may be a temperature that the pressure medium received by at least one of the at least one pressure medium flow generators is not permitted to exceed. The first selected temperature described above may be equal to the nominal maximum pressure medium temperature.

[0023] The press apparatus may include a heating unit, which may be located downstream of at least one of the at least one pressure medium flow generators and upstream of the outlet, and may be configured to heat the pressure medium being guided in at least one pressure medium guide channel such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or equal to a second selected temperature. During use of the press apparatus, the pressure medium upon inflow into the inlet may have a temperature equal to or within a certain temperature range, where the constant temperature may exceed a first selected temperature, or the constant temperature range may include temperatures exceeding the first selected temperature. The second selected temperature described above may be equal to or within a certain temperature range. Therefore, the heating unit may heat the pressure medium being guided in at least one pressure medium flow channel such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or above the selected temperature, which may be the temperature of the pressure medium as it is guided into the at least one pressure medium flow channel through its inlet.

[0024] For example, at least one pressure medium guideway may be located at least partially outside the pressure vessel.

[0025] At least one of the above-mentioned pressure medium flow generators may, for example, include at least one pressure intensifier.

[0026] The heating unit and / or cooling unit may, for example, include at least one heat exchanger unit.

[0027] At least one pressure medium guiding path may be configured to guide a pressure medium out of the internal space and into an inlet, to guide the pressure medium introduced into the inlet from the inlet to an outlet, and to guide the pressure medium out of the outlet and back into the internal space.

[0028] The press device may be configured to process at least one article. The press device may include a loading section, which may be arranged within the internal space and arranged such that a flow of pressure medium through the loading section is permitted. The loading section may be arranged to hold at least one article therein during use of the press device.

[0029] At least one pressure medium flow path may be different from the internal space and the loading section. Generally, at least one pressure medium flow path may be considered to be part of the press device separated from the internal space and / or the loading section, and in some cases, the pressure medium may be prevented from mixing with the pressure medium within the internal space and / or the loading section when the pressure medium is being conveyed through at least one pressure medium flow path.

[0030] At least one pressure medium flow path may include at least one of, for example, one or more conduits, one or more channels, one or more pipes, one or more tubes, etc., which may be configured to guide a pressure medium therethrough.

[0031] At least one pressure medium flow generator may be configured to generate a flow of pressure medium within the internal space in a direction from the outlet to the inlet.

[0032] The pressure vessel may include at least one end closure. At least one pressure medium guiding path may exit the pressure vessel through a passage through the end closure of the pressure vessel and enter the pressure vessel through a passage through the same end closure. Each or any end closure(s) may be arranged to be selectively opened and closed.

[0033] The pressure vessel may have at least two end closures. At least one pressure medium guideway exits the pressure vessel through a passage through a first end closure of the end closures of the pressure vessel and enters the pressure vessel through a passage through a second end closure of the end closures of the pressure vessel, the second end closure being possibly different from the first end closure.

[0034] The press apparatus may be configured to process at least one article. At least a portion of the internal space may be arranged to hold at least one article. The press apparatus may include a heating medium reservoir, which may be or can be fluidly connected to a pressure vessel. The press apparatus may include at least one heater, which may be configured to selectively and controllably heat the heating medium in the heating medium reservoir. The press apparatus may include at least one heating medium flow generator, which may be configured to repeatedly generate a flow of heating medium from the heating medium reservoir into the pressure vessel and then a flow of heating medium from the pressure vessel into the heating medium reservoir before the pressure vessel holds the pressure medium in its internal space for use in the press apparatus, thereby generating a circulation of heating medium between the heating medium reservoir and the pressure vessel for a selected period of time. At least one heater may be configured to heat the heating medium in a heating medium reservoir, and at least one heating medium flow generator may be configured to create a circulation of the heating medium between the heating medium reservoir and the pressure vessel for a selected period of time to heat any article in the internal space to a selected temperature. At least one heating medium flow generator may be configured to create a flow of heating medium from the pressure vessel into the heating medium reservoir to draw the heating medium out of the pressure vessel once the temperature of the article(s) in the internal space reaches the selected temperature. With such a configuration, the article(s) to be processed by the press device may be preheated by the pressure medium held in the internal space before the processing of the article(s) is carried out.

[0035] A pressure vessel may comprise a pressure cylinder. A pressure vessel may comprise a pressure cylinder and one or more end closures, such as a first end closure and a second end closure. In some cases, the end closures of a pressure vessel may be formed by a portion of the pressure cylinder. Each or either of the first and / or second end closures may include, for example, a lid, or be formed by a lid. The second end closure may be on the opposite side of the first end closure. For example, the first and second end closures may be located at opposite ends of the pressure vessel (or pressure cylinder). Thus, the first end closure may be at the first end of the pressure vessel, and the second end closure may be at the second end of the pressure vessel.

[0036] Channels, conduits and / or tubes, etc., may be arranged on or on the outer surface of the outer wall of a pressure cylinder or pressure vessel to provide a flow of coolant to cool the outer wall of the pressure cylinder or pressure vessel. Prestressing means may be provided on the outer surface of the outer wall of the pressure cylinder or pressure vessel, and optionally in any channels, conduits and / or tubes, etc., for the coolant. If the prestressing means is located directly on the outer surface of the outer wall of the pressure cylinder or pressure vessel, the channels, conduits and / or tubes, etc., for the coolant may be located on (e.g., outside the prestressing means) such that they at least partially surround the prestressing means. The prestressing means may be provided, for example, in the form of a wire (e.g., made of steel) that can be wound multiple times to form one or more strips, preferably in several layers, around any channels, conduits and / or tubes, etc., for the coolant, which may be located on or on the outer surface of the outer wall of the pressure cylinder or pressure vessel. The prestressing means may be arranged to apply a radial compressive force to the pressure cylinder or pressure vessel. For example, the pressure vessel may be of the so-called monoblock type, in which case the aforementioned prestressing means may not be used.

[0037] Furthermore, the press apparatus may include axial prestressing means for absorbing axial forces that may act on one or more of the end closures of the pressure vessel. Such axial prestressing means may include, for example, a frame, which may be positioned to hold one or more of the end closures of the pressure vessel. The frame may extend outside the pressure vessel from one end closure at one end of the pressure vessel to the other end closure at the other end of the pressure vessel.

[0038] As described above, after the articles are loaded into the pressure vessel, the pressure vessel may then be sealed. This may be followed by a pressurization stage and / or a heating stage. The pressurization and heating stages may be carried out simultaneously. The pressurization stage may involve introducing a pressure medium into the (sealed) pressure vessel to reach a selected pressure within the pressure vessel. The heating stage may involve heating the pressure medium to achieve, for example, a desired or required temperature. In some cases, before introducing the pressure medium into the pressure vessel, the pressure medium may be preheated to a temperature that takes into account the adiabatic heating rise that occurs due to the pressurization of the pressure medium inside the pressure vessel. Such an adiabatic heating rise may be, for example, (approximately) 2-9°C / 100MPa, depending on the media composition. By preheating the pressure medium before introducing it into the pressure vessel, and then pressurizing the pressure medium inside the pressure vessel, a temperature of the pressure medium within, for example, 2-5°C of the desired or required temperature may be achieved. Thus, the preheated pressure medium may be introduced into the pressure vessel. Subsequently, the temperature of the pressure medium can be adjusted to a desired or required temperature (or approximately desired or required temperature) by adjusting the pressure in the pressure vessel, and as a result, the desired or required temperature (or approximately desired or approximately required temperature) is reached by adiabatic heating of the pressure medium. Thus, by such adiabatic heating, the temperature of the pressure medium in the pressure vessel may rise by, for example, 2°C to 5°C to reach the desired or required temperature (or approximately desired or approximately required temperature). Preheating of the pressure medium can be carried out, for example, using one or more heaters, such as one or more electric heaters, arranged with respect to a pressure medium source or storage tank connected to or connectable to the pressure vessel, so that the pressure medium can be heated while it is in the pressure medium source or storage tank.

[0039] As mentioned above, the pressure medium can be, for example, water. Water is generally considered incompressible. However, at very high pressures, water becomes compressible, and heat is generated during compression. In principle, the temperature of water rises by approximately 4°C for every 1000 bar up to 6000 bar. The interaction between the amount of (solid) load or article(s) to be processed and the amount of pressure medium (e.g., water) can affect how the operation of a press machine configured to process at least one article by WIP is controlled, or should be controlled. The solid load / article(s) is negligibly compressible compared to the pressure medium, and therefore the temperature rise of the solid load / article(s) as a result of the pressure increase will not be the same as the temperature rise of the pressure medium as a result of the pressure increase. When choosing how to control the operation of a press machine configured to process at least one article by WIP (for example, when selecting control parameters for such operation), the thermal properties of the load / article(s) should be taken into consideration. For example, the pressure build-up speed and (if any) the preheating temperature to be used should be considered. The temperature rise of the pressure medium over a given time period during the pressure build-up sequence may differ from the temperature rise of the load / item(s) over that same time period during the pressure build-up sequence; therefore, depending on the considerations above, this should be taken into account when determining which pressure build-up speed to use. Rapid pressure build-up may not be necessary if the temperature of the load / item(s) is held at a certain level below the target "holding" temperature for a certain period of time during the time it takes to reach the target "holding" pressure. This means that, in some cases, a slower pressure build-up may be preferable in order to reach the target "holding" temperature and target "holding" pressure simultaneously or substantially simultaneously. Furthermore, control of operation may also need to take into account any nominal maximum temperature and / or nominal maximum pressure that may not be permitted to be exceeded for safety reasons.

[0040] Preheating of articles(s) before processing may be carried out while the articles(s) are outside the pressure vessel. In some cases, articles(s) may be preheated outside the pressure vessel while they are placed in a container for containing the articles(s), which may be configured to be placed inside the pressure vessel during processing of the articles(s) by the press. The container may typically be a configuration called a loading basket.

[0041] The press apparatus may include a heating unit, which may be located downstream of at least one of the pressure medium flow generators and upstream of the outlet, and may be configured to controllly heat the pressure medium being induced in at least one pressure medium guide channel. A method according to a second aspect of the present invention may include controlling the heating unit to heat the pressure medium being induced in at least one pressure medium guide channel such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or greater than a second selected temperature.

[0042] According to a third aspect of the present invention, a computer program product is provided. The computer program product is configured to perform the method according to a second aspect of the present invention when executed in a control unit configured to control the operation of a press apparatus according to a first aspect of the present invention.

[0043] A fourth aspect of the present invention provides a computer-readable storage medium. The computer-readable storage medium stores a computer program product configured to perform the method according to the second aspect of the present invention when executed in a control unit configured to control the operation of a press apparatus according to the first aspect of the present invention.

[0044] The control unit may be configured to control the operation of one or more components of the press apparatus, such as at least one pressure medium flow generator, a cooling unit, and / or a heating unit.

[0045] The control unit may be communicatively coupled to one or more components of the press apparatus, such as at least one pressure medium flow generator, a cooling unit, and / or a heating unit, by any suitable wired and / or wireless means known in the art. The control unit may be configured to control the operation of one or more components of the press apparatus, such as at least one pressure medium flow generator, a cooling unit, and / or a heating unit, by transmitting one or more messages or commands, data, etc., to those components, which may cause one or more components of the press apparatus to perform, for example, a method according to a second aspect of the present invention.

[0046] The control unit may be alternatively called a control device, control module, or control circuit. The control unit may include, or be composed of, any suitable central processing unit (CPU), programmable logic microcontroller (PLC), microcontroller, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), etc., or any combination thereof. The control unit may optionally be capable of executing software instructions stored in a computer program product, for example, in the form of memory. The memory may be any combination of read-write memory (RAM) and read-only memory (ROM). The memory may also include persistent memory, such as magnetic memory, optical memory, solid-state memory, or remote-mount memory, or any combination thereof.

[0047] Computer-readable storage media may include, for example, digital multipurpose disks (DVDs) or floppy disks (registered trademarks), or any other suitable type of computer-readable means or computer-readable (digital) storage media, such as, but not limited to, non-volatile memory, hard disk drives, compact discs (CDs), flash memory, magnetic tape, Universal Serial Bus (USB) memory elements, Zip drives, etc.

[0048] Further objects and advantages of the present invention are described below by exemplary embodiments. It should be noted that the present invention relates to all possible combinations of the features described in the claims. Further features and advantages of the present invention will become apparent upon consideration of the appended claims and the description herein. Those skilled in the art will understand that different features of the present invention can be combined to produce embodiments other than those described herein.

[0049] Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0050] [Figure 1] Figure 1 is a schematic diagram of a press machine according to one embodiment of the present invention. [Figure 2] Figure 2 is a schematic partial cross-sectional view of the pressure vessel of a press apparatus according to one embodiment of the present invention. [Figure 3] Figure 3 is a schematic partial cross-sectional view of a portion of the pressure vessel shown in Figure 2, at the closed end of one of the pressure vessels. [Figure 4] Figure 4 is a schematic partial cross-sectional view of a portion of the pressure vessel shown in Figure 2, at the other end of the pressure vessel's closed section. [Figure 5] Figure 5 is a perspective view of the end closing section shown in Figure 4. [Figure 6] Figure 6 is a schematic diagram of a press machine according to one embodiment of the present invention. [Figure 7]Figure 7 is a schematic partial cross-sectional view of the pressure vessel of a press apparatus according to one embodiment of the present invention. [Figure 8] Figure 8 is a schematic flowchart of the method according to one embodiment of the present invention. [Figure 9] Figure 9 is a schematic flowchart of the method according to one embodiment of the present invention. [Modes for carrying out the invention]

[0051] All drawings are schematic and not necessarily to scale, and generally show only the parts necessary to illustrate embodiments of the present invention, where other parts may be omitted or merely suggested.

[0052] Next, the present invention will be described below with reference to the accompanying drawings illustrating exemplary embodiments of the invention. However, the present invention can be embodied in many different forms and should not be construed as being limited to the embodiments of the present invention described herein, but rather these embodiments are provided as examples so that this disclosure may convey the scope of the invention to those skilled in the art.

[0053] Figure 1 is a schematic diagram of a press device 100 according to one embodiment of the present invention. The press device 100 comprises a pressure vessel 1. The pressure vessel 1 has an internal space 5. The pressure vessel 1 is arranged to hold a pressure medium in the internal space 5 during use of the press device 100. The press device 100 may be configured to process at least one article (not shown in Figure 1). The press device 100 may include a loading compartment (not shown in Figure 1), which may be located within the internal space 5 and may be arranged to allow the flow of a pressure medium through the loading compartment. The loading compartment may be arranged to hold at least one article in it during use of the press device 100. The pressure medium may comprise a fluid, such as a liquid and / or a gas. The fluid may comprise, for example, water, and / or oil, and / or another suitable liquid. The oil may comprise, for example, mineral oil. The gas may comprise, for example, an inert gas, such as argon gas.

[0054] The press device 100 includes a pressure medium guide channel 6. The pressure medium guide channel 6 has an inlet 7 and an outlet 8 that are in fluid communication with the internal space 5, and extends between these inlet 7 and outlet 8. The pressure medium guide channel 6 is configured to guide the pressure medium from the inlet 7 to the outlet 8. The pressure medium flow path 6 can be defined by at least one of, for example, one or more tubes, one or more pipes, one or more channels, one or more conduits, etc. Figure 1 illustrates one pressure medium guide channel 6, but it should be understood that the press device 100 may have several pressure medium guide channels, each configured to guide the pressure medium from the inlet 7 to the outlet 8. Each or any of the several pressure medium guide channels may be configured to guide the pressure medium from an inlet to an outlet that is in fluid communication with the internal space 5. Therefore, there may be inlets and outlets associated with each of the several pressure medium guide channels.

[0055] The pressure medium guide path 6 may be configured to guide the pressure medium out of the internal space 5 into the inlet 7, to guide the pressure medium introduced into the inlet 7 from the inlet 7 to the outlet 8, and to guide the pressure medium out of the outlet 8 and back into the internal space 5.

[0056] According to the embodiment of the present invention illustrated in Figure 1, the pressure medium guideway 6 is located at least partially outside the pressure vessel 1. It should be understood that this is not mandatory, and the pressure medium guideway 6 may be located at least partially inside the pressure vessel 1.

[0057] Figure 1 schematically illustrates a pressure medium channel 6 that exits the pressure vessel 1 at one location and enters the pressure vessel 1 at another location. Extensions of the pressure medium channel 6 between different locations in the pressure vessel 1 or between different locations within the pressure vessel 1 can be realized in different ways. For example, the pressure vessel 1 may have at least two end closures, such as a first end closure and a second end closure (not shown in Figure 1). The pressure medium guide channel 6 may exit the pressure vessel 1 through a passage through the first end closure of the end closures of the pressure vessel 1 and enter the pressure vessel 1 through a passage through the second end closure of the end closures of the pressure vessel 1. The second end closure may be different from the first end closure, or the second end closure may be the same as the first end closure (i.e., the pressure medium guide channel 6 may enter and exit the pressure vessel 1 within or at a single end closure of the pressure vessel 1).

[0058] The press apparatus 100 includes at least one pressure medium flow generator configured to generate a flow of pressure medium that enters the inlet 7, passes through the pressure medium guideway 6, and exits the outlet 8. The at least one pressure medium flow generator may be configured to generate a flow of pressure medium within the internal space 5 in the direction from the outlet 8 to the inlet 7. Thus, the at least one pressure medium flow generator and the pressure medium guideway 6 can generate and / or maintain circulation of the pressure medium within the internal space 5, for example, over a long period of time. Circulation may occur during the pressurizing phase, i.e., the holding phase, of the processing cycle, during which any article in the pressure vessel 1 is subjected to a rise in pressure within the pressure vessel 1 (e.g., a constant pressure or near a constant pressure within the pressure vessel 1, and possibly a constant temperature or near a constant temperature within the pressure vessel 1) for a certain (e.g., selected) period of time.

[0059] The press apparatus 100 includes a cooling unit 20, which is located downstream of the inlet 7 and is configured to cool the pressure medium being guided through the pressure medium guide path 6.

[0060] At least one of the at least one pressure medium flow generators, the pressure medium flow generator 14, is located downstream of the cooling unit 20. The at least one of the at least one pressure medium flow generators, the pressure medium flow generator 14, is configured to receive the flow of pressure medium cooled by the cooling unit 20 and generate a flow of pressure medium in the pressure medium guide path 6 toward the outlet 8. The press device 100 may include one or more additional pressure medium flow generators, each or any of which may be located, for example, within the pressure vessel 1, and each or any of which may include, for example, one or more fans, one or more ejectors, and / or one or more pumps.

[0061] According to an embodiment of the present invention illustrated in Figure 1, at least one pressure medium flow generator 14, among the at least one pressure medium flow generators, comprises a pressure intensifier 24 and a pump 25, the pump 25 may be called a supply pump.

[0062] The cooling unit 20 is configured to cool the pressure medium being guided through the pressure medium guide path 6 such that the temperature of the pressure medium received by at least one of the pressure medium flow generators 14 does not exceed a first selected temperature.

[0063] At least one of the pressure medium flow generators, the at least one pressure medium flow generator 14, may be associated with a nominal maximum pressure medium temperature, which may be a temperature that the pressure medium received by the at least one pressure medium flow generator 14 is not permitted to exceed. The first selected temperature described above may be equal to the nominal maximum pressure medium temperature.

[0064] According to an embodiment of the present invention illustrated in Figure 1, the press apparatus 100 includes a heating unit 21. The heating unit 21 is located downstream of at least one pressure medium flow generator 14 and upstream of the outlet 8 among at least one pressure medium flow generator. The heating unit 21 is configured to heat the pressure medium being guided through the pressure medium guide path 6 such that the temperature of the pressure medium in the pressure medium flow exiting the outlet 8 is equal to or greater than a second selected temperature.

[0065] Each or both of the cooling unit 20 and the heating unit 21 may, for example, comprise one or more heat exchanger units, but other or other types of heating / cooling units are also possible.

[0066] During use of the press device 100, the pressure medium flowing into the inlet 7 may have a temperature equal to a certain temperature or within a certain temperature range. The above-mentioned certain temperature may exceed the first selected temperature, or the certain temperature range may include temperatures exceeding the first selected temperature. The above-mentioned second selected temperature may be equal to the above-mentioned certain temperature or may be within the above-mentioned certain temperature range.

[0067] For example, according to embodiments of the present invention illustrated in Figure 1, if the temperature of the pressure medium received by the pressure medium flow generator 14 (e.g., the intensifier 24) becomes relatively high, the intensifier 24 may not function or operate properly, or may even malfunction. The cooling unit 20 can cool the pressure medium in the pressure medium flow path 6 to ensure that the temperature of the pressure medium received by the pressure medium flow generator 14 (e.g., the intensifier 24) does not exceed a temperature for which the pressure medium flow generator 14, such as the intensifier 24, is not rated. This temperature may be called the nominal maximum pressure medium temperature, as described above. If it is determined (e.g., sensed) that the temperature of the pressure medium to be received by the pressure medium flow generator 14 (e.g., the intensifier 24) will not exceed a temperature for which the pressure medium flow generator 14, such as the intensifier 24, is not rated, then the cooling unit 20 may not perform any cooling of the pressure medium in the pressure medium flow path 6, or it may only adjust the temperature of the pressure medium in the pressure medium flow path 6 toward any set point that can be defined.

[0068] The configuration of the press apparatus 100 as illustrated in Figure 1—and in particular the configuration of the pressure medium flow channel 6—may be particularly advantageous if the pressure medium flow generator 14 is of a type or configuration that may not function or operate properly, or even malfunction, if the temperature of the pressure medium received by the pressure medium flow generator 14 becomes relatively high. For example, the press apparatus 100 may be configured to process at least one article by isotropic pressurization, in which case the temperature of the pressure medium may become relatively high during use of the press apparatus 100. If the temperature of the pressure medium induced into the pressure medium flow channel 6 becomes too high for the pressure medium flow generator 14 to function properly, the cooling unit 20 may cool the pressure medium being induced in the pressure medium flow channel 6 so that the temperature of the pressure medium received by the pressure medium flow generator 14 does not exceed a temperature above which the pressure medium flow generator 14 may not function or operate properly, or in some cases may even malfunction. In some cases, the heating unit 21 may then heat the pressure medium being guided in the pressure medium channel 6 so that the temperature of the pressure medium in the pressure medium flow exiting the outlet 8 exceeds or matches the selected temperature, which may be equal to or near the temperature of the pressure medium when it is guided into the pressure medium channel 6 through the inlet 7.

[0069] According to an embodiment of the present invention illustrated in Figure 1, the press apparatus 100 may include a control valve 22 located downstream of the cooling unit 20 and a check valve assembly 23 located downstream of the control valve 22. As illustrated in Figure 1, the check valve assembly 23 takes in a pressure medium output from the cooling unit 20 as input and outputs a pressure medium to be supplied to or transported to the heating unit 21. As also illustrated in Figure 1, the check valve assembly 23 is further fluidically coupled to a pump 25. The control valve 22 and the check valve assembly 23 may be used to control the flow of pressure medium output from the intensifier 24. The pump 25, which can operate at relatively low pressures, may be used to supply pressure medium to the intensifier 24, comprising, for example, oil and / or water or any other fluid.

[0070] The pressurization phase of the processing cycle, i.e., once the pressure in the pressure vessel 1 has risen to a certain pressure level, may involve the following operations: Pump 25 supplies pressure medium to the intensifier 24. As the intensifier 24 performs its stroke, the pressure rises in the pressure medium being fed into the intensifier 24, and the pressurized pressure medium is delivered (e.g., pumped) to the check valve assembly 23. During this operation, the control valve 22 is closed (i.e., not allowing any flow of pressure medium through it, or only allowing a very small amount of flow of pressure medium through it), and all the pressure medium is delivered (e.g., pumped) to the heating unit 21. The heat exchanger 21 may heat the pressure medium to a certain temperature, or to a temperature above a certain temperature, before it enters the pressure vessel 1 through the outlet 8. The intensifier 24 operates until a selected pressure level in the pressure vessel 1 is reached. The pump 25 and the intensifier 24 may then be stopped.

[0071] A pressing or holding phase of a processing cycle in which any article in the pressure vessel 1 is subjected to increased pressure within the pressure vessel 1 (e.g., at or near a constant pressure within the pressure vessel 1, and possibly at or near a constant temperature within the pressure vessel 1) for a selected period of time may involve the following: During the pressing phase, the control valve 22 is open (e.g., to allow the pressure medium to flow through it). Instead of the pressure medium being supplied to the intensifier 24 by the pump 25 (as in the pressurizing phase described above), the pressure medium from the cooling unit 20 is transported through the control valve 22 and supplied to the intensifier 24 via the check valve assembly 23. For example, by shifting the intensifier in the stroke direction and performing a pumping stroke, the pressure medium may be directed to the heating unit 21 via the check valve assembly 23. The flow rate of the pressure medium during the pressing phase (e.g., the mass flow rate of the pressure medium) may be lower than the flow rate of the pressure medium during the pressurizing or pumping phase. Generally, the flow rate of the pressure medium can be adjusted, for example, by adjusting the stroke rate and / or stroke speed of the pressure intensifier 24.

[0072] While the at least one pressure medium flow generator 14 of the at least one pressure medium flow generator has been described as comprising a pressure intensifier 24 and a pump 25, it should be understood that this is merely an example and can be modified. For example, a pressure medium flow generator other than a pressure intensifier or of a different type may be used in the at least one pressure medium flow generator 14 of the at least one pressure medium flow generator. Therefore, the at least one pressure medium flow generator 14 of the at least one pressure medium flow generator does not necessarily have to be equipped with a pressure intensifier.

[0073] As illustrated in Figure 1, a check valve 28 or similar may be present between the pump 25 and the pressure intensifier 24. Additionally or alternatively, for example, one or more (additional) check valves or similar may be provided in at least one of the pressure medium flow generators 14 among the at least one pressure medium flow generator.

[0074] As described above, the pressure medium guideway 6 may exit the pressure vessel 1 via a passage through a first end closure of the end closure of the pressure vessel 1 and enter the pressure vessel 1 via a passage through a second end closure of the end closure of the pressure vessel 1, which may be different from the first end closure. However, modifications are possible. For example, the pressure medium guideway 6 may exit the pressure vessel 1 via a passage through an end closure of the pressure vessel 1 (for example, this may be the only end closure of the pressure vessel 1) and enter the pressure vessel 1 via a passage through the same end closure. Examples of such configurations are illustrated in Figures 2 to 5.

[0075] As described above, with the configuration illustrated in Figure 1, circulation of the pressure medium within the internal space 5 over a long period of time can be generated and / or maintained during the pressing phase, i.e., holding phase, of the processing cycle. It should be understood that such circulation can also be generated and / or maintained during other phases of the processing cycle, such as the pressurizing or pumping phase, when the pressure medium is introduced into the pressure vessel 1 so that the pressure inside the pressure vessel 1 rises to a certain pressure level 1. In such cases, it may be beneficial to use a configuration that provides several pressure medium guideways, each of which may be configured to guide the pressure medium from an inlet to an outlet that is in fluid communication with the internal space 5. (According to the embodiment of the present invention illustrated in Figure 1, there is only one such pressure medium guideway 6.) Each of the several pressure medium guideways may have its own inlet and outlet that is in fluid communication with the internal space 5, or different pressure medium guideways may share an inlet and outlet. Each or any of these pressure medium guideways may be located outside the pressure vessel 1 and may be configured and / or arranged in accordance with (or generally in accordance with) the pressure medium guideway 6 as illustrated in Figure 1 and described above. For example, each or any of these pressure medium guideways may be provided with a component between the inlet 7 and outlet 8 of the pressure medium guideway 6 as illustrated in Figure 1 and described above. In order to generate and / or maintain the circulation of the pressure medium within the internal space 5 during the pressurizing or pumping phase of the processing cycle, for one or more of the pressure medium guideways, the control valve 22 may be opened (for example, to allow the flow of the pressure medium through it), while for other(s) of the pressure medium guideways, the control valve 22 may be closed (i.e., to allow no or only a small amount of the flow of the pressure medium through it). For one or more of the pressure medium guideways through which the control valve 22 is open, each intensifier(s) may be configured to shift its stroke direction and perform a pumping stroke, thereby directing the pressure medium to the pressure vessel 1 via its respective check valve assembly / multiple check valve assemblies.

[0076] Figure 2 is a schematic partial cross-sectional view of the pressure vessel 1 of a press apparatus according to one embodiment of the present invention. The same reference numerals in Figures 1 and 2 indicate the same or similar components having the same or similar function.

[0077] According to an embodiment of the present invention illustrated in Figure 2, the pressure vessel 1 comprises a pressure cylinder 10 (sometimes simply called a cylinder), a first end closure 11, and a second end closure 12. Although not explicitly illustrated in Figure 2, one or both of the first end closure 11 and the second end closure 12 may be configured to be openable and closable, for example, using opening and closing means known in the art. The second end closure 12 is located on the opposite side from the first end closure 11, and as a result, the first end closure 11 and the second end closure 12 are located at opposite ends of the pressure vessel 1.

[0078] The pressure vessel 1 has an internal space 5. The pressure vessel 1 is arranged to hold a pressure medium within the internal space 5 during use of the press device. According to an embodiment of the present invention illustrated in Figure 2, the pressure vessel 1 includes a loading compartment 2, which is located within the internal space 5. The loading compartment 2 is arranged to allow the flow of a pressure medium through it. The loading compartment 2 is arranged to hold at least one article within it during use of the press device.

[0079] According to an embodiment of the present invention illustrated in Figure 2, the loading compartment 2 is defined by the walls of a cylindrical container 3, which may also be called a loading basket without loss of generality, and the internal space 5 may be at least partially defined by the loading compartment 2, for example, by the inside of the (e.g., cylindrical) container that defines the loading compartment 2. At least the envelope surface of the container 3 may be impermeable to the pressure medium. One or more ends of the container 3 (e.g., the lower and / or upper ends of the container 3) may be provided with one or more through holes that allow the pressure medium to pass through there, thereby allowing the flow of the pressure medium through the loading compartment 2. The container 3, i.e., the loading basket, may, in principle, be made of any material capable of withstanding the pressure in which at least one article is intended to be processed. The container 3, i.e., the loading basket, may be made of, for example, steel or another ferrous alloy. The container 3, i.e., the loading basket, may preferably be made of a material having relatively low thermal conductivity, such as a polymer or plastic material. However, other materials with relatively low thermal conductivity are also considered. The loading basket may have an internal structure including a partition that may have a platform or similar, which may allow items to be placed at different levels within the loading basket along its length.

[0080] While the cylindrical geometric shapes of the pressure vessel 1, internal space 5, and loading compartment 2, as illustrated in Figure 2, may be preferred geometric shapes—or one of several preferred geometric shapes—it should be understood that such geometric shapes of the pressure vessel 1, internal space 5, and loading compartment 2 are not mandatory, and other or other types of geometric shapes of such components are possible.

[0081] According to an embodiment of the present invention illustrated in Figure 2, the container 3 may be at least partially surrounded by a housing 9, such as a liner or jacket, and the housing 9 may be cylindrical, for example (and as illustrated in Figure 2). One or both of the pressure cylinder 10 and the housing 9 (e.g., the liner) may be insulated, for example, by a relatively thin insulating layer (not shown in Figure 2) that is adjacent to or bonded to the inner surfaces of the pressure cylinder 10 and the housing 9, respectively.

[0082] The press apparatus has an inlet 7 and an outlet (not shown in Figure 2, see Figure 5) that are in fluid communication with an internal space 5, and includes a pressure medium guideway 6 extending between the inlet 7 and the outlet. The pressure medium guideway 6 is configured to guide the pressure medium from the inlet 7 to the outlet. Similar to the embodiment of the present invention illustrated in Figure 1, the pressure medium guideway 6 of the press apparatus illustrated in Figure 2 is located at least partially outside the pressure vessel 1 (i.e., extends outward). The pressure medium flow path 6 may be defined by at least one of, for example, one or more tubes, one or more pipes, one or more channels, one or more conduits, etc. It should be understood that only a portion of the pressure medium guideway 6 is illustrated in Figure 2. More specifically, only the portion of the pressure medium guideway 6 close to the inlet 7 is shown in Figure 2, and the rest of the pressure medium guideway 6 is not shown in Figure 2. The portion of the pressure medium guide path 6 located outside the pressure vessel 1 may be configured and / or arranged in relation to other components of the press apparatus, for example, according to the embodiment of the present invention illustrated in Figure 1 (or generally according to the embodiment of the present invention illustrated in Figure 1).

[0083] Figure 3 is a schematic partial cross-sectional view of a portion of the pressure vessel 1 shown in Figure 2, at the first end closure 11. Figure 4 is a schematic partial cross-sectional view of a portion of the pressure vessel 1 shown in Figure 2, at the second end closure 12. However, the pressure cylinder 10 is not shown in Figure 4. Figure 5 is a perspective view of the second end closure 12 shown in Figure 4.

[0084] As illustrated in Figure 5, the pressure medium guide channel 6 has an inlet 7 and an outlet 8 that are in fluid communication with an internal space 5 (not shown in Figure 5), and extends between these inlet 7 and outlet 8. Only the portions of the pressure medium guide channel 6 closest to the inlet 7 and outlet 8 are shown in Figure 5, while other portions of the pressure medium guide channel 6 are not shown in Figure 5. The portions of the pressure medium guide channel 6 outside the pressure vessel 1 may be configured and / or arranged in relation to other components of the press device according to one embodiment of the present invention, for example, according to the embodiment of the present invention illustrated in Figure 1 (or generally according to the embodiment of the present invention illustrated in Figure 1). It should be understood that the positions of the inlet 7 and outlet 8 in the end closure 12 may differ from those illustrated in Figure 5.

[0085] In Figures 2 to 5, as illustrated by the arrows within the pressure vessel 1, the pressure medium being guided through the pressure medium guide channel 6 may exit the pressure medium guide channel 6 through its outlet 8 and enter the internal space 5. The pressure medium is then guided into the loading compartment 2, which, according to the illustrated embodiment, is achieved by a through-hole at the lower end of the container 3 that allows the pressure medium to pass through it. In Figures 2 to 5, as illustrated by the arrows within the pressure vessel 1, the flow of the pressure medium through the loading compartment 2 is permitted. The pressure medium being guided within the loading compartment 2 may then exit the loading compartment 2 and enter (again) the internal space 5 (at a different location in the internal space 5 than where the pressure medium entered the loading compartment 2), which, according to the illustrated embodiment, is achieved by a through-hole at the upper end of the container 3 that allows the pressure medium to pass through it. The use of the terms “upper end” and “lower end” of container 3 is for illustrative purposes only and relates to how pressure vessel 1 is illustrated in Figure 2, and should be understood as not necessarily referring to a specific orientation of pressure vessel 1 when the press device is in use. In any embodiment of the present invention, the pressure vessel may be positioned in use such that, for example, the longitudinal axis of the pressure vessel is oriented perpendicular or substantially perpendicular to a vertical line (e.g., a plumb line), or parallel or substantially parallel to a vertical line (e.g., a plumb line).

[0086] As perhaps best illustrated in Figure 2, a flow of pressure medium exists through the loading compartment 2 in the direction from the lower end of container 3 to the upper end of container 3, or more generally, from the first end of pressure vessel 1 to the second end of pressure vessel 1, the second end of which may be on the opposite side of the first end. The flow of pressure medium passing through the through hole in the upper end of container 3 enters a passage defined by the gap between the upper end of container 3 and the lower surface of the first end closure 11. According to the illustrated embodiment, and perhaps best illustrated in Figure 3, a spring element 29 may be provided, configured to bias container 3 toward the second end closure 12, thereby facilitating or allowing the formation of a passage defined by the gap between the upper end of container 3 and the lower surface of the first end closure 11. Several such spring elements may be provided to facilitate or allow the formation of a passage defined by the gap between the upper end of container 3 and the lower surface of the first end closure 11. As illustrated in Figures 2, 3, and 4, the pressure medium can also flow from the gap between the upper end of the container 3 and the lower surface of the first end closure 11 into a passage along the outer envelope surface of the container 3 defining the loading compartment 2, in the direction from the upper end of the container 3 to the lower end of the container 3 (i.e., in the direction toward the second end closure 12). Thus, in the illustrated embodiment of the present invention, the loading compartment 2 does not occupy the entire internal space 5, but the internal space 5 includes a gap between the outer envelope surface of the container 3 defining the loading compartment 2 and the inner surface of the pressure cylinder 10, through which the pressure medium can flow. Once the pressure medium is guided along the outer envelope surface of the container 3 defining the loading compartment 2 to the lower end of the container 3, it can then enter the inlet 7 of the pressure medium guide passage 6. For example, a flow of pressure medium can be generated in the internal space 5 between the outlet 8 of the pressure medium guide passage 6 and the inlet 7 of the pressure medium guide passage 6, and through the pressure medium guide passage 6 from its inlet 7 to its outlet 8 by at least one pressure medium flow generator, which may include one or more fans, one or more ejectors, one or more pumps and / or one or more intensifiers.This allows for the circulation of the pressure medium within the pressure vessel 1 to be generated and / or maintained, for example, over a long period of time. In particular, the circulation of the pressure medium within the internal space 5 and the loading compartment 2 can be generated and / or maintained, for example, over a long period of time. Figures 2 to 5 illustrate specific ways in which the flow of the pressure medium within the internal space 5 between the outlet 8 of the pressure medium guide passage 6 and the inlet 7 of the pressure medium guide passage 6 can be generated, and it should be understood that these are modifiable. For example, the flow of the pressure medium may be generated only in a portion of the internal space 5, and not necessarily throughout the entire internal space 5.

[0087] As illustrated in Figures 2 and 3, a flow limiting unit 30, such as a valve, may be located at the first end closure 11. Such a flow limiting unit 30 may be used to fluidly connect the pressure vessel 1 to a heating medium reservoir for holding a heating medium, such as oil, in order to preheat any articles(s) to be processed by the press device 100 by a pressure medium held in the internal space 5 before the articles(s) are processed. As shown in Figures 2 and 3, the flow limiting unit 30 may be used to fluidly connect the pressure vessel 1 to the heating medium reservoir via the first end closure 11. Such configurations are further described below with reference to Figures 6 and 7. A flow limiting unit 35, which may be similar to or identical to the flow limiting unit 30 and can fluidly connect the pressure vessel 1 to the heating medium reservoir via a second end closure 12, may be located at the second end closure 12, as illustrated in Figures 2, 4 and 5, as an addition or alternative. For example, as described below with reference to Figures 6 and 7, the flow of heating medium from the heating medium storage tank may enter the pressure vessel 1 through the flow limiter 35 of the second end closure 12, flow through the pressure vessel 1, and exit the pressure vessel 1 through the flow limiter 30 of the first end closure 11. The flow limiters 30, 35 may be equipped with valves or constituted by valves, according to embodiments of the present invention illustrated in Figures 2 to 5. However, it should be understood that other or other types of flow limiters may be used as alternatives or additions.

[0088] Figure 6 is a schematic diagram of a press machine 100 according to one embodiment of the present invention. The same reference numerals in Figures 1 to 5 and Figure 6 indicate the same or similar components having the same or similar functions. The press machine 100 is configured to process at least one article (not shown in Figure 6). At least a portion of the internal space 5 is arranged to hold at least one article.

[0089] According to an embodiment of the present invention illustrated in Figure 6, the press apparatus 100 includes a heating medium storage tank 31, which is fluidly connected to or can be fluidly connected to the pressure vessel 1. The heating medium storage tank 31 is configured to hold a heating medium, which may include, for example, oil. The heating medium storage tank 31 may include, for example, a tank or another suitable type of container for holding a heating medium such as oil.

[0090] As shown in Figure 6, the heating medium storage tank 31 may be fluidly connected to the pressure vessel 1 by one or more flow limiting units 30, 35. The flow limiting units are called valves 30, 35, but it should be understood that other or other types of flow limiting units may be used as alternatives or additions. As also shown in Figure 6, the press device 100 has two valves 30, 35 located in the first end closure 11 and the second end closure 12, respectively. However, it should be understood that, in principle, only one valve may be required to implement fluid connectivity between the heating medium storage tank 31 and the pressure vessel 1. Furthermore, each or either of the valves 30, 35 may be located in a different location other than the end closure of the pressure vessel 1. Also, the valves 30, 35 do not necessarily have to be located in different end closures of the pressure vessel 1, but may be located in the same end closure of the pressure vessel 1, for example.

[0091] Furthermore, according to an embodiment of the present invention illustrated in Figure 6, the press apparatus 100 includes a heater 32 configured to selectively and controllably heat the heating medium in the heating medium storage tank 31. The heater 32 may comprise, for example, one or more electric heaters. To facilitate the heater 32 heating the heating medium in the heating medium storage tank 31 (for example, uniformly), the press apparatus 100 may include a pump 34, which is another type of flow generator, and the pump 34 may be fluidically coupled to the heating medium storage tank 31 and configured to circulate the heating medium in the heating medium storage tank 31. Thus, the pump 34 may be called a circulation pump.

[0092] Furthermore, according to an embodiment of the present invention illustrated in Figure 6, the press apparatus 100 includes a heating medium flow generator 33. The heating medium flow generator 33 may include, for example, a pump (e.g., a circulation pump). The heating medium flow generator 33 is configured to repeatedly (e.g., continuously) generate a flow of heating medium from the heating medium reservoir 31 into the pressure vessel 1, and then a flow of heating medium from the pressure vessel 1 into the heating medium reservoir 31, before the pressure vessel 1 holds the pressure medium in its internal space 5 for use by the press apparatus 100, thereby generating a circulation of heating medium between the heating medium reservoir 31 and the pressure vessel 1 for a selected period of time.

[0093] The flow rate of the heating medium in the circulation of the heating medium between the heating medium storage tank 31 and the pressure vessel 1 (e.g., the mass flow rate of the heating medium) can be significantly higher, for example, about 10 times higher, than the flow rate of the pressure medium in the circulation of the pressure medium that may be carried out during the pressing stage, i.e., holding stage, of the processing cycle (e.g., the mass flow rate of the pressure medium).

[0094] The heater 32 is configured to heat the heating medium in the heating medium storage tank 31, and the heating medium flow generator 33 is configured to create a circulation of the heating medium between the heating medium storage tank 31 and the pressure vessel 1 for a selected time period so as to heat any article in the internal space 5 to a selected temperature. The heating medium flow generator 33 is configured to create a flow of heating medium from the pressure vessel 1 into the heating medium storage tank 31 in order to draw the heating medium out of the pressure vessel 1 once the temperature of the article(s) in the internal space 5 reaches the selected temperature. Heating of any article in the internal space 5 to the selected temperature may be carried out at atmospheric pressure. Determination that the temperature of the article(s) in the internal space 5 has reached the selected temperature may be carried out, for example, by sensing the temperature of the article(s) using one or more temperature sensors, or by sensing one or more temperatures in a press device that indicates or represents the temperature of the article(s). The temperature of the article(s) may mean the temperature on the surface of the article(s). The temperature of the heating medium in the internal space 5 and / or the loading compartment 2 (see Figures 2 to 4) may be considered to indicate or represent the temperature of the item(s). Alternatively or additionally, the temperature of the heating medium in the heating medium storage tank 31 and / or in any channels, conduits, passages, etc. that fluidly connect the heating medium storage tank 31 to the pressure vessel 1 may be considered to indicate or represent the temperature of the item(s). The heater 32 may be controlled based on one or more temperature values ​​sensed in the internal space 5 and / or the loading compartment 2 and / or the heating medium storage tank 31. For this purpose, one or more temperature sensors (not shown in the figures) may be provided in the internal space 5, the loading compartment 2, the heating medium storage tank 31 and / or in any channels, conduits, passages, etc. that fluidly connect the heating medium storage tank 31 to the pressure vessel 1.

[0095] The determination that the temperature of an item(s) in the internal space 5 has reached a selected temperature is accompanied by the determination that the temperature of the item(s) in the internal space 5 is within a certain temperature range (for example, within a few degrees Celsius of the selected temperature), and the temperature of the item(s) in the internal space 5 can be considered to have reached the selected temperature, provided that the temperature of the item(s) in the internal space 5 is within that temperature range.

[0096] As illustrated in Figure 6, the pressure medium held within the internal space 5 allows the items(s) to be processed by the press device 100 to be preheated before processing is carried out. For example, as illustrated in Figure 6, the pressure medium held within the internal space 5 allows the items(s) to be processed by the press device 100 to be preheated before the pressurizing step of the processing cycle is carried out.

[0097] Figure 7 is a schematic partial cross-sectional view of a pressure vessel 1 of a press apparatus according to one embodiment of the present invention. The pressure vessel 1 illustrated in Figure 7 has the same structure as the pressure vessel 1 illustrated in Figure 2. The same reference numerals in Figure 7 and Figure 2 indicate the same or similar components having the same or similar functions. Referring to the embodiment of the present invention illustrated in Figure 6, the arrows in the pressure vessel 1 illustrated in Figure 7 indicate how, during the circulation of the heating medium between the heating medium storage tank 31 and the pressure vessel 1, for example, for a selected time period, the heating medium from the heating medium storage tank 31 may flow through the pressure vessel 1, in particular through the internal space 5 and the loading compartment 2, during the circulation of the heating medium between the heating medium storage tank 31 and the pressure vessel 1, for example, for a selected time period. As illustrated by the arrows in the pressure vessel 1 in Figure 7, the flow of the heating medium from the heating medium storage tank 31 may enter the pressure vessel 1 via the flow limiting section 35, flow through the pressure vessel 1, and exit the pressure vessel 1 via the flow limiting section 30.

[0098] Figure 8 is a schematic flowchart of Method 200 according to one embodiment of the present invention. Method 200 is carried out in a press apparatus. The press apparatus comprises a pressure vessel having an internal space. The pressure vessel is arranged to hold a pressure medium in the internal space during use of the press apparatus. The press apparatus comprises at least one pressure medium guide path. The at least one pressure medium guide path has an inlet and an outlet, extends between the inlet and the outlet, and these inlet and outlet are in fluid communication with the internal space. The at least one pressure medium guide path is configured to guide the pressure medium from the inlet to the outlet. The press apparatus comprises at least one pressure medium flow generator, which is configured to controllly generate a flow of pressure medium that enters the inlet, passes through the at least one pressure medium guide path, and exits the outlet. The press apparatus comprises a cooling unit, which is located downstream of the inlet, and is configured to controllly cool the pressure medium being guided through the at least one pressure medium guide path.

[0099] Method 200 comprises controlling at least one pressure medium flow generator in 201 to generate a flow of pressure medium entering the inlet and toward the cooling unit. At least one of the at least one pressure medium flow generator is located downstream of the cooling unit and is configured to receive a flow of pressure medium cooled by the cooling unit.

[0100] Method 200 comprises controlling at least one of at least one pressure medium flow generators in 202 to generate a flow of pressure medium in at least one pressure medium guideway toward an outlet.

[0101] Method 200 comprises controlling a cooling unit in 203 to cool the pressure medium being guided through at least one pressure medium guide path such that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a first selected temperature.

[0102] After step 203, method 200 may be terminated. However, method 200 may be repeated over a long period of time, during which time circulation of the pressure medium in the pressure vessel is generated and / or maintained.

[0103] Figure 9 is a schematic flowchart of Method 200 according to one embodiment of the present invention. Method 200 illustrated in Figure 9 is similar to Method 200 illustrated in Figure 8 and includes operations or steps 201, 202, and 203 as described above with reference to Method 200 illustrated in Figure 8. Method 200 illustrated in Figure 9 includes an additional step or operation 204. According to the embodiment of the present invention illustrated in Figure 9, the press apparatus may include a heating unit. The heating unit may be located downstream of at least one of the at least one pressure medium flow generators and upstream of the outlet. The heating unit may be configured to controllly heat the pressure medium being guided through at least one pressure medium guide channel such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or greater than a second selected temperature. Method 200 illustrated in Figure 9 includes, in 204, controlling the heating unit to heat the pressure medium being guided through at least one pressure medium guide channel such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or greater than a second selected temperature.

[0104] After step 204, the method 200 illustrated in Figure 9 may be terminated. However, the method 200 illustrated in Figure 9 may be repeated over a long period of time, during which the circulation of the pressure medium within the pressure vessel is generated and / or maintained.

[0105] In conclusion, a press apparatus is disclosed comprising a pressure vessel having an internal space and at least one pressure medium guideway having an inlet and an outlet in fluid communication with the internal space and extending between the inlet and the outlet. The press apparatus comprises a cooling unit located downstream of the inlet and configured to cool the pressure medium being guided through the at least one pressure medium guideway. At least one pressure medium flow generator located downstream of the cooling unit is configured to receive the flow of pressure medium cooled by the cooling unit so that the temperature of the pressure medium does not exceed a first selected temperature, and to generate a flow of pressure medium in the at least one pressure medium guideway toward the outlet. Related methods are also disclosed.

[0106] While the present invention has been illustrated in the accompanying drawings and the foregoing description, such illustrations should be considered illustrative or exemplary and not limiting, and the present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and achieved by those skilled in the art when carrying out the claimed invention, based on a review of the drawings, this disclosure, and the accompanying claims. In the accompanying claims, the term "comprising" does not exclude other elements or processes, and the indefinite article "a" or "an" does not exclude the plural. The mere fact that certain means are described in different dependent claims does not imply that combinations of these means cannot be used advantageously. None of the reference numerals in the claims should be construed as limiting.

Claims

1. A press device (100), A pressure vessel (1) having an internal space (5), wherein the pressure vessel is arranged to hold a pressure medium within the internal space during use of the press device. The internal space has an inlet (7) and an outlet (8) that are in fluid communication with the internal space, and at least one pressure medium guide path (6) extends between the inlet (7) and the outlet (8), wherein the at least one pressure medium guide path is configured to guide the pressure medium from the inlet to the outlet. A pressure medium flow generator configured to generate a flow of pressure medium that enters the inlet, passes through the at least one pressure medium guide path, and exits the outlet, A cooling unit (20) is located downstream of the inlet and is configured to cool the pressure medium being guided through the at least one pressure medium guide path, Equipped with, At least one of the at least one pressure medium flow generators (14) is located downstream of the cooling unit and is configured to receive the flow of the pressure medium cooled by the cooling unit and to generate the flow of the pressure medium in the at least one pressure medium guide path toward the outlet. A press apparatus, wherein the cooling unit is configured to cool the pressure medium being guided through the at least one pressure medium guide path such that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a first selected temperature.

2. The press apparatus according to claim 1, wherein at least one of the at least one pressure medium flow generators is associated with a nominal maximum pressure medium temperature which is a temperature that the pressure medium received by at least one of the at least one pressure medium flow generators is not permitted to exceed, and the first selected temperature is equal to the nominal maximum pressure medium temperature.

3. A heating unit (21) is positioned downstream of at least one of the at least one pressure medium flow generators and upstream of the outlet, and is configured to heat the pressure medium being guided in the at least one pressure medium guide path such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or greater than a second selected temperature. The press apparatus according to claim 1 or 2, further comprising the following:

4. The press apparatus according to claim 3, wherein, during use of the press apparatus, the pressure medium has a temperature equal to or within a certain temperature range when flowing into the inlet, and the constant temperature exceeds the first selected temperature, or the constant temperature range includes temperatures exceeding the first selected temperature, and the second selected temperature is equal to or within the certain temperature range.

5. The press apparatus according to any one of claims 1 to 4, wherein the at least one pressure medium guide path is located at least partially outside the pressure vessel.

6. The press apparatus according to any one of claims 1 to 5, wherein at least one of the at least one pressure medium flow generators comprises at least one pressure intensifier (24).

7. The pressing apparatus according to any one of claims 1 to 6, wherein the heating unit and / or the cooling unit comprises at least one heat exchanger unit.

8. The press apparatus according to any one of claims 1 to 7, wherein the at least one pressure medium guide path is configured to guide the pressure medium out of the internal space and into the inlet, to guide the pressure medium introduced into the inlet from the inlet to the outlet, and to guide the pressure medium out of the outlet and back into the internal space.

9. The press device according to any one of claims 1 to 8, wherein the press device is configured to process at least one article, and further comprises a loading compartment located within the internal space and arranged to allow the flow of a pressure medium through the loading compartment, the loading compartment being arranged to hold at least one article therein during use of the press device.

10. The press apparatus according to any one of claims 1 to 9, wherein the at least one pressure medium flow generator is further configured to generate a flow of the pressure medium in the internal space in the direction from the outlet to the inlet.

11. The press apparatus according to any one of claims 1 to 10, wherein the pressure vessel comprises at least one end closure, and the at least one pressure medium guide path exits the pressure vessel through a passage through the end closure of the pressure vessel and enters the pressure vessel through the same passage through the end closure.

12. The press apparatus according to any one of claims 1 to 10, wherein the pressure vessel comprises at least two end closures, and the at least one pressure medium guide path exits the pressure vessel through a passage through a first end closure of the end closures of the pressure vessel and enters the pressure vessel through a passage through a second end closure of the end closures of the pressure vessel, the second end closure being different from the first end closure.

13. The press device is configured to process at least one article, and at least a portion of the internal space is arranged to hold the at least one article, and the press device is A heating medium storage tank (31) is fluid-connected to or can be fluid-connected to the pressure vessel, At least one heater (32) configured to selectively and controllably heat the heating medium in the heating medium storage tank, Before the pressure vessel holds the pressure medium in the internal space for use of the press device, at least one heating medium flow generator (33) is configured to repeatedly generate a flow of heating medium from the heating medium reservoir into the pressure vessel, and then a flow of heating medium from the pressure vessel into the heating medium reservoir, thereby creating a circulation of heating medium between the heating medium reservoir and the pressure vessel for a selected time period, Furthermore, The press apparatus according to any one of claims 1 to 12, wherein the at least one heater is configured to heat the heating medium in the heating medium storage tank, the at least one heating medium flow generator is configured to circulate the heating medium between the heating medium storage tank and the pressure vessel for a selected period of time so as to heat any article in the internal space to a selected temperature, and the at least one heating medium flow generator is configured to circulate the heating medium from the pressure vessel into the heating medium storage tank so as to draw the heating medium out of the pressure vessel when the temperature of the article in the internal space reaches the selected temperature.

14. A method (200) in a press apparatus (100), wherein the press apparatus comprises a pressure vessel (1) having an internal space, wherein the pressure vessel is arranged to hold a pressure medium in the internal space during use of the press apparatus and has an inlet (7) and an outlet (8) in fluid communication with the internal space, and at least one pressure medium guide path (6) extending between the inlet (7) and the outlet (8), wherein the at least one pressure medium guide path is configured to guide the pressure medium from the inlet to the outlet, and at least one pressure medium flow generator configured to controllably generate a flow of pressure medium entering the inlet, passing through the at least one pressure medium guide path, and exiting the outlet, and a cooling unit (20) located downstream of the inlet and configured to controllably cool the pressure medium being guided in the at least one pressure medium guide path, the method is: (201) comprising controlling the at least one pressure medium flow generator to generate a flow of pressure medium that enters the inlet and is directed toward the cooling unit, At least one of the at least one pressure medium flow generators (14) is located downstream of the cooling unit and is configured to receive the flow of the pressure medium cooled by the cooling unit, and the method is Controlling at least one of the at least one pressure medium flow generators to generate a flow of the pressure medium in the at least one pressure medium guide path toward the outlet (202), (203) Controlling the cooling unit to cool the pressure medium being guided through the at least one pressure medium guide path so that the temperature of the pressure medium received by at least one of the at least one pressure medium flow generators does not exceed a first selected temperature, A way to further enhance it.

15. The press apparatus further comprises a heating unit (21) positioned downstream of at least one of the at least one pressure medium flow generators and upstream of the outlet, and configured to controlly heat the pressure medium being guided in the at least one pressure medium guide path, and the method is Controlling the heating unit to heat the pressure medium being guided through the at least one pressure medium guide path such that the temperature of the pressure medium in the pressure medium flow exiting the outlet is equal to or greater than a second selected temperature (204) The method according to claim 14, further comprising:

16. A computer program product configured to perform the method (200) described in claim 14 or 15 when executed in a control unit configured to control the operation of a press apparatus according to any one of claims 1 to 13.

17. A computer-readable storage medium storing a computer program product configured to perform the method (200) described in claim 14 or 15 when executed in a control unit configured to control the operation of a press apparatus according to any one of claims 1 to 13.

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