Sanitary steam compressor

Abstract

A hygienic compression device having an impeller housing, an impeller, and a motor. The impeller housing has an axial inlet and a radial outlet. The axial inlet receives flash vapor from the flash vapor outlet of the flash vessel. The radial outlet provides compressed flash steam to the heat treatment apparatus. The impeller is arranged in the impeller shell. The motor is configured to rotate the impeller. Flash steam enters the inlet and is radially accelerated and compressed in response to rotation of the impeller.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 433,881, filed on December 20, 2023, which is incorporated herein by reference in its entirety. Technical field

[0003] This application relates to a steam compressor that is used in a facility for ultra - high - temperature treatment of fluid foods, such as milk or milk - based products, baby foods, plant - based beverages, or nutritional beverages. The facility includes direct heat treatment equipment in which the fluid is heat - treated by supplying steam. Background art

[0004] In a UHT (Ultra - High - Temperature) facility, steam is injected into the fluid food in a perfusion chamber, for example, in such a way that the fluid food is heated to a temperature of approximately 140 °C. Subsequently, the fluid food is supplied to a so - called holding chamber, in which the fluid food is held in a heated state for a predetermined time (about 2 to 15 seconds). Then, the fluid food is transferred to a flash vessel, in which the water obtained from the steam is removed in such a way that the solid content of the fluid food leaving the flash vessel is the same as the solid content of the fluid food supplied to the perfusion chamber before heat treatment. After processing in the flash vessel, the fluid food is usually transferred to a homogenizer and then cooled and packaged.

[0005] EP 0794706 discloses a perfusion facility for high - temperature treatment of fluid foods such as whey protein concentrate and cottage cheese. The perfusion facility has a perfusion chamber in which the fluid is heat - treated by steam supplied to the perfusion chamber. The food is introduced at the top of the perfusion chamber as a bundle of separate and mainly downward - directed jets. The lower part of the perfusion chamber is used to collect the food and has a cooling wall provided with a cooling jacket. The outlet opening of the perfusion chamber is provided at the bottom of the perfusion chamber, and the outlet opening is connected to the inlet of a positive - displacement pump. The outlet of the positive - displacement pump is connected to the inlet of a vacuum chamber that is used to remove the water added during steam perfusion from the food.

[0006] US 4,419,301 discloses a method of heating a fluid to a sterilization temperature. The fluid is heated by direct contact with steam while the fluid is in the form of a very thin free - falling film or a continuous downward flow. After the sterilization process, the added steam is removed in a flash vessel, and the resulting steam is condensed into condensate that will be discarded.

[0007] AU 61233 discloses a perfusion facility for continuously sterilizing liquids, in which the unsterilized liquid is preferably sprayed into a sterilization chamber supplied with steam after preheating, and in which the liquid heated by the steam is kept for a predetermined time, characterized in that the top of the sterilization chamber (see Figure 1 the perfusion chamber

[15] therein) includes at least one row of outlet openings for guiding the liquid downward, and the outlet openings are positioned along a circle. The facility has a perfusion chamber in which the fluid is heat-treated by steam supplied to the perfusion chamber. The outlet openings of the perfusion chamber are provided at the bottom of the perfusion chamber, and the outlet openings are connected to the inlet of a holding device. The outlet of the holding device is connected to the inlet of a vacuum chamber ( Figure 1 , item 7) for removing the water added during steam perfusion from the food.

[0008] WO 2022 / 122401 discloses a method of heating a fluid to a sterilization temperature. The fluid is heated by direct contact with a steam injection device. After heating, the added steam is removed in a flash vessel cooling device, and the steam is condensed into condensate to be discarded. The present disclosure describes using steam injection instead of steam perfusion, but having the same cooling device, a flash cooler, in which the excess steam is condensed and discarded in the flash cooler.

[0009] The perfusion facility uses high temperatures for a short time to kill microorganisms. This technique is widely used in the dairy industry, in which products lose nutritional value, flavor, and appearance as microorganisms multiply. These organisms multiply at a certain temperature, but if these organisms are not present in the product, the product can be stored for many months without refrigeration. Compared with other UHT processes, steam perfusion achieves this purpose with minimal thermal degradation. Steam perfusion helps to protect essential components such as vitamins and produces a umami product with outstanding quality. Steam perfusion provides the necessary kill rate for commercial sterility and can handle a wide range of product viscosities, covering fluids from milk, pudding, ice cream, baby food, condensed milk, processed cheese, plant-based beverages, sauces and creams to lotions.

[0010] There is always a need to improve the design and function of heat treatment facilities such as perfusion facilities to achieve a method that is lower in cost, more energy-efficient, and more environmentally friendly than the prior art.

[0011] Accordingly, it is desirable to provide a hygienic steam compressor for a heat treatment facility without the undesirable qualities of a conventional steam compressor. Summary of the Invention

[0012] The object of the present application is to provide a hygienic steam compressor for use in a perfusion facility for the ultra-high treatment of fluid food. Due to improved internal heat recovery, the steam compressor is more cost-effective and environmentally friendly than the prior art.

[0013] According to a first aspect of the present application, this object is achieved by providing a compression device having an impeller housing, an impeller, and a motor. The impeller housing has an axial inlet and a radial outlet. The axial inlet receives flash steam from the flash steam outlet of a flash vessel. The radial outlet supplies compressed flash steam to a heat treatment device. The impeller is arranged in the impeller housing. The motor is configured to rotate the impeller. The flash steam enters the inlet and is radially accelerated and compressed in response to the rotation of the impeller.

[0014] According to a second aspect of the present application, this object is achieved by providing a facility for heat-treating fluid food, where the fluid food is, for example, milk, milk-based products, baby food, liquid concentrates of baby food, or nutritional beverages. The facility includes: a heat treatment device having a fluid food inlet provided at the top of the heat treatment device, a fluid food outlet provided at the bottom of the heat treatment device, and a first steam inlet provided at the top of the heat treatment device. The fluid food is subjected to heat treatment by supplying fresh steam and / or flash steam into the heat treatment device. The fresh steam is supplied into the heat treatment device through a fresh steam pipe connected to the first steam inlet. The flash vessel has a fluid food inlet at the side of the vessel and a fluid food outlet at the bottom of the flash vessel. The fluid food outlet of the heat treatment device is connected to the fluid food inlet of the flash vessel through a pipe and a pump. The fluid food outlet of the flash vessel is connected to a pipe and a pump for discharging the fluid food from the flash vessel. The flash vessel further includes a flash steam outlet provided at the top of the flash vessel. The flash steam outlet is connected to a flash steam pipe. The flash steam pipe is connected to the inlet of a compression arrangement. The flash steam pipe is adapted to supply flash steam to the compression arrangement, where the flash steam is compressed. A second flash steam pipe is connected to the outlet of the compression arrangement. The second flash steam pipe is adapted to transfer the flash steam to the heat treatment device.

[0015] Embodiments of the present application allow the reuse of low-pressure waste flash steam from a UHT facility instead of simply releasing the low-pressure waste flash steam into the atmosphere. The waste flash steam is approximately 50% of the heating energy loss of the UHT facility. Therefore, when 1000 kg of steam is added for perfusion UHT heating, conventional direct UHT loses 500 kg of steam through waste flash steam. Using a flash steam recovery system, such as the flash steam recovery system of the present application, all such 50% of the waste flash steam heat can be recovered and reused. Embodiments of the present application increase the reuse of steam for perfusion heating from 50% to 100%.

[0016] In a first possible implementation of the first aspect, the second flash steam pipe is connected to the fresh steam pipe, thereby allowing the heat treatment equipment to have only one steam inlet.

[0017] In a second possible implementation of the first aspect, the second flash steam pipe is connected to a second steam inlet arranged at the top of the heat treatment equipment, thereby providing a solution in which the injection of fresh steam and flash steam can be adjusted independently of each other.

[0018] In a third possible implementation of the first aspect, the heat steam recompression device is connected to the second flash steam pipe, thereby further compressing the flash steam if necessary.

[0019] In a fourth possible implementation of the first aspect, the compression arrangement includes at least one compression device that facilitates mechanically compressing the flash steam to a higher pressure, so that the flash steam can be reused.

[0020] In a fifth possible implementation of the first aspect, the compression arrangement includes two compression devices connected in series, thereby allowing the steam pressure to be reduced in appropriately large steps.

[0021] In a sixth possible implementation of the first aspect, the compression device includes a steam compressor.

[0022] In a seventh possible implementation of the first aspect, the compression device includes a heat pump.

[0023] In a ninth possible implementation of the first aspect, the compression device includes a turbocharger, thereby further reducing the amount of energy required to operate the facility.

[0024] In a tenth possible implementation of the first aspect, fresh steam is generated by a steam boiler, which is a simple and reliable solution.

[0025] In an eleventh possible implementation of the first aspect, the steam boiler is adapted to supply steam to the turbocharger, thereby eliminating the need to power the turbocharger separately.

[0026] In a twelfth possible implementation of the first aspect, the pipes and pumps are adapted to convey fluid food to the aseptic homogenizer.

[0027] In a thirteenth possible implementation of the first aspect, the fluid food is heat-sensitive.

[0028] In a fourteenth possible implementation of the first aspect, the facility does not include a condenser connected to the outlet of the flash vessel.

[0029] In a fifteenth possible implementation of the first aspect, the heat treatment equipment includes a steam injection chamber.

[0030] In a sixteenth possible implementation of the first aspect, the heat treatment device includes a steam injector device.

[0031] According to a second aspect of the present application, this object is achieved by a method for operating an ultra-high temperature treatment facility having a heat treatment device, in which a fluid food is heat-treated by fresh steam and / or flash steam. The method includes: supplying the fluid food to the heat treatment device, supplying fresh steam and / or flash steam to the heat treatment device, removing the fluid food from the heat treatment device, supplying the fluid food to a flash vessel, removing the fluid food from the flash vessel, removing the flash steam from the flash vessel, supplying the flash steam to a compressor arrangement, the compressor arrangement compressing the flash steam, and then supplying the flash steam to the heat treatment device. This method allows the reuse of the low-pressure waste flash steam of the UHT facility instead of simply releasing the low-pressure waste flash steam into the atmosphere. By using a flash steam recovery system, such as the flash steam recovery system of the present application, all 50% of the waste steam can be recovered and reused. Therefore, in one aspect of the present application, only the filling chamber needs to be filled with external fresh steam in the start-up sequence, and after start-up, the filling chamber can be heated with recycled steam without an external fresh steam supply. In a first possible implementation of the second aspect, the compressor arrangement includes at least two compressor devices arranged in series, or three compressor devices, or four compressor devices, and the flash steam is incrementally compressed by the compressor devices. This solution helps the step-by-step mechanical compression of the flash steam. In certain implementations, when the compressor devices are connected in series, the connection includes water injection.

[0032] In a second possible implementation of the second aspect, at least two of the steps are performed simultaneously.

[0033] In a third possible implementation of the second aspect, the method further includes: after compressing the flash steam in the compressor arrangement and before supplying the flash steam to the heat treatment device, supplying the flash steam through a thermal steam recompression device.

[0034] In a fourth possible implementation of the second aspect, the heat treatment device includes a steam filling chamber.

[0035] In a fifth possible implementation of the second aspect, the heat treatment device includes a steam injector device.

[0036] The above object and other objects are achieved by the features of the independent claims. Further implementations are obvious from the dependent claims, the description, and the drawings.

[0037] These and other aspects of the present application will become apparent from the accompanying drawings and the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above summary of the present application, as well as the following detailed description, will be better understood when read in conjunction with the accompanying drawings. For purposes of illustrating the present application, the drawings show embodiments of the present application. However, it should be understood that the present application is not limited to the exact arrangements, examples, and mechanisms shown.

[0039] Figure 1 is a schematic view of an embodiment of an ultra-high temperature treatment facility.

[0040] Figure 2 is suitable for use in Figure 1 a perspective view of an impeller and a translucent impeller housing suitable for use in a compression device in the ultra-high temperature treatment facility shown.

[0041] Figure 3 is suitable for use in Figure 1 a cross-sectional view of a compression device having an impeller and an impeller housing installed therein, suitable for use in the ultra-high temperature treatment facility shown. DETAILED DESCRIPTION

[0042] Generally, embodiments of the compression devices described herein are suitable for use with any system that includes a compression device. The compression devices are suitable for use with ultra-high temperature treatment (“UHT”) facilities as described herein. For example, as described herein, advantages of the compression devices include: energy savings in the production of steam for food processing; allowing for hygienic cleaning of the impeller and impeller housing; allowing the motor for the compression device to be separated from the food processing portion of the ultra-high temperature treatment facility; etc. A particular advantage of the compression devices described herein is their suitability for use with a mechanical vapor recompression (MVR) process to enable energy savings in the reuse of steam. MVR can enable a UHT facility to reduce the evaporation energy used by 90% or more. MVR uses the energy recovered from flash steam to mechanically produce reusable high-pressure / high-energy steam. From Boyle's law, for a gas, PV / T (pressure volume / temperature) is constant (PV / T = K). During steam compression, the pressure and temperature increase. Thus, thermal energy can be reused. Energy that is typically lost during compression is recovered, resulting in an efficient UHT process cycle. These and other advantages are described herein. More specifically, embodiments of the compression devices described herein are applicable to various types of processing facilities.

[0043] Specifically, in certain embodiments, the present disclosure provides a sterile hygienic steam compressor device intended for use in an infusion MVR loop. The compressor device is part of a heat pump loop that re-uses the flash vessel steam, thereby reducing new steam consumption and energy consumption. In some embodiments, the compressor device may operate as a single compressor, but may also operate in series with other compressor devices that require some desuperheating. In some embodiments, in the case of series operation of the compressor devices, the compressor includes water injection before, inside, or after the compressor. Additionally or alternatively, desuperheating may be achieved through heat exchange and / or gas injection. For example, the gas may be CO2.

[0044] Figure 1 An installation for the ultra-high temperature treatment of liquid food is shown. The liquid food may be any food in liquid form, but the disclosed installation is particularly suitable for temperature-sensitive foods that should be heated to kill bacteria only for a short time in order to preserve their flavor, consistency, and nutritional quality. Examples of such liquid foods are milk, milk-based products, baby food, liquid concentrates of baby food, or nutritional beverages. The liquid food may have a high dry matter content (40% and higher) and / or a high protein content (6% or higher). The fluid food is initially stored in a tank 22. The tank 22 is connected to a sterilization circuit 23 in which the food is sterilized. The fluid food is conveyed from the tank 22 to the heat treatment device 1 through pipes 2 and pumps 24, 25. In the middle, the pipe 2 is connected to a plate heat exchanger 26 for preheating the fluid food from about 1 °C to about 100 °C, or more specifically, from about 5 °C to about 75 °C.

[0045] The fluid food enters the heat treatment device 1, such as a steam infusion chamber, as a bundle of separate liquid food jets 7 through a plurality of openings in nozzles at the top of the steam infusion chamber 1. Hot steam is injected into the steam infusion chamber 1 through a steam inlet, which is, for example, a circumferential steam distribution chamber. In the steam infusion chamber 1, the liquid food jets converge with the hot steam, whereby the food is heated and absorbs the steam.

[0046] In an embodiment, the heat treatment device 1 includes a steam injector device instead of a steam infusion chamber. The steam injector device heats the food by mixing the food from pipe 2 with steam from pipes 14 and / or 3 inside the steam injector device. However, for simplicity, the following description will only refer to the steam infusion chamber.

[0047] The steam injection chamber 1 is preferably substantially rotationally symmetric about a vertical axis. The upper part of the steam injection chamber 1 has a hollow cylindrical portion and a top shaped like a truncated cone. The bottom is releasably connected to the upper part by a flange connection to allow access to the interior of the steam injection chamber 1 for cleaning and / or maintenance. In an embodiment, the bottom has a shape similar to a truncated cone.

[0048] In addition, the steam injection chamber 1 is connected to pipes 4 and 5 which are used for supplying and removing a liquid, such as water, for cooling the bottom of the steam injection chamber 1. A cooling jacket connected to pipes 4, 5 may be provided around the bottom. The cooling jacket keeps the bottom portion cool to prevent or minimize fouling or burnout of the liquid food in contact with the inner wall of the bottom portion. The cooling jacket provides a mantle of cooling water or other cooling medium around the bottom. The mantle is separated by a spiral transverse wall which guides the cooling water in a spiral pattern around the bottom. The cooling medium inlet passes through the pump housing and enters the portion of the mantle which also extends into the pump housing. From the portion inside the pump housing, the spiral path of the cooling medium continues spirally upwards towards the cooling medium outlet which is connected to pipe 5 at the top of the cooling jacket and near the top of the bottom. The liquid food jet terminates at the funnel-shaped inner wall of the bottom. The bottom collects the liquid food from the liquid food jet and guides the liquid food to an outlet opening at the lower end of the steam injection chamber 1, which is also the lower end of the bottom and also the inlet of the pump 6.

[0049] The lower part of the bottom forms the outlet opening of the steam injection chamber 1. In one embodiment, the outlet opening of the steam injection chamber 1 is seamlessly connected to the inlet of the pump 6, while in another embodiment the steam injection chamber 1 is just connected to the pump 6. In an embodiment, this is achieved by the lower end of the bottom which is made of a steel plate, such as stainless steel, and connected to the pump housing by a welded joint. In an embodiment, the pump housing is provided with a circular ridge or circular upright flange to facilitate welding the pump housing to the lower end of the bottom. After welding, the transition portion between the bottom and the pump housing / pump inlet formed by the welded joint is machined to provide a completely smooth surface without cracks or crevices which may be difficult to clean or flush.

[0050] The pump 6 can be a centrifugal pump or a positive displacement pump. The pump 6 is of a known conventional type, such as a gear pump or a cam pump, and is connected to the outlet of the steam injection chamber 1. The housing of the pump 6 is provided with temperature sensors at positions where adjacent surfaces are kept clean of burnings, such as by the teeth of a gear or by the projections of a rotor. In this way, reliable control of the facility can be ensured. In another embodiment, the temperature sensor is a needle probe sensor located directly after the pump 6, at the start of the pipeline 9. The outlet of the pump 6 is connected via the pipeline 9 to the inlet of a flash vessel 10 of a conventionally known type, such as a vacuum chamber. In one embodiment, the pipeline 9 includes a valve at the end of the pipeline 9, just before the flash vessel 10.

[0051] The flash vessel 10 is adapted to remove the water added to the fluid food during the heat treatment in the steam injection chamber 1. The excess water added by the steam during the heat treatment is removed through the steam pipeline 8. The concentrated fluid food is discharged in a conventionally known manner through the pipeline 12 and the pump 13 and conveyed to the aseptic homogenizer 17. Then, the homogenized fluid food is cooled by one or more plate heat exchangers 21, for example from about 75 °C to about 20 °C, and transferred to the storage unit 19 or the packaging process. In other instances, the homogenized fluid food is cooled from a high temperature of up to 95 °C to a room temperature of about 20 °C, a refrigerated temperature of about 5 °C, and transferred to the storage unit 19 or the packaging process.

[0052] The plate heat exchangers 21 and 26 are connected together with the water heater 27 in a continuous heating / cooling circuit, and the water heater 27 heats the heating water before it enters the preheater 26.

[0053] In the prior art, low-pressure steam, such as flash steam, is typically discharged to the atmosphere or condensed in a cooling tower. Instead, the low-pressure waste steam can be mechanically compressed to a higher pressure so that it can be reused. The steam tables show that when steam condenses, approximately 25% of its heat remains in the condensate, i.e., the concentrated fluid food. Using a flash steam recovery system such as Figure 1 the one shown, approximately half of this heat can be recovered as flash steam. However, the UHT process requires that the flash steam in direct contact with the food has a food-grade quality.

[0054] The steam injection chamber 1 has: a fluid food inlet provided at the top of the steam injection chamber 1; a fluid food outlet provided at the bottom of the steam injection chamber 1; and a first steam inlet also provided at the top of the steam injection chamber 1. "Top" refers to the upper part of the steam injection chamber, and "bottom" refers to the lower part of the steam injection chamber, as seen when the steam injection chamber is arranged so that it extends substantially vertically.

[0055] The heat-sensitive fluid food is supplied through pipe 2 to the fluid food inlet, and in the steam injection chamber 1, the heat-sensitive fluid food is heat-treated by supplying fresh steam and / or flash steam into the steam injection chamber 1. "Fresh steam" refers to steam generated, for example, by a steam boiler. "Flash steam" refers to steam recovered from a flash vessel. Through the fresh steam pipe 3, the fresh steam is supplied into the steam injection chamber 1 through the first steam inlet. The other end of the steam pipe 3 is connected to a steam boiler. The steam boiler generates steam at about 7 - 20 bar. The steam supplied to the steam injection chamber 1 has a pressure of about 5 bar. Therefore, a control valve can be used to reduce the amount of steam and create a pressure drop from 7 - 15 bar to 5 bar. In a preferred embodiment, the pressure drop is reused as the power to drive a turbocharger.

[0056] The flash vessel 10 includes: a fluid food inlet at the top of the flash vessel 10; a fluid food outlet at the bottom of the flash vessel 10. "Top" refers to the upper part of the flash vessel, and "bottom" refers to the lower part of the flash vessel, as seen when the flash vessel is arranged to extend substantially vertically. The inlet at the top is a horizontal and tangential inlet at the top.

[0057] The fluid food outlet of the steam injection chamber 1 is connected through pipe 9 and pump 6 to the fluid food inlet of the flash vessel 10. The fluid food outlet of the flash vessel 10 is connected to pipe 12 and pump 13 for discharging the fluid food from the flash vessel 10.

[0058] The flash vessel 10 includes a flash steam outlet provided at the top of the flash vessel 10. The flash steam outlet is connected to the first flash steam pipe 8. In a specific example, when leaving the flash vessel 10, the flash steam has a temperature of about 70 °C and an absolute pressure of about 0.3 bar. In other examples, the flash steam can have a temperature range of about 50 °C to about 90 °C and an absolute pressure range of about 0.1 bar to about 1.0 bar.

[0059] The first flash steam pipe 8 is connected to the inlet of the compression arrangement 16 and is used to supply the flash steam from the flash vessel 10 to the compression arrangement 16. Then the flash steam is compressed in the compression device to about 2 - 10 bar, or more particularly to about 5 - 7 bar, and the temperature after desuperheating is about 100 - 200 °C, or more particularly about 130 - 170 °C.

[0060] The outlet of the compression arrangement 16 is connected to the second flash steam pipe 14, which is used to transfer the flash steam to the steam injection chamber 1. In one embodiment, the second flash steam pipe 14 is connected to the fresh steam pipe 3 such that the fresh steam and the flash steam are mixed before entering the steam injection chamber 1 through the first steam inlet. In another embodiment, the second flash steam pipe 14 is directly connected to the second steam inlet provided at the top of the steam injection chamber 1. In this embodiment, fresh steam is supplied into the steam injection chamber 1 through the first steam inlet, and flash steam is supplied into the steam injection chamber 1 through the second steam inlet. These two embodiments can be combined.

[0061] In addition, the second flash steam pipe 14 can be connected to a compression device, such as a device 20 for thermal steam recompression, also known as TVR (thermal vapor recompression). If the flash steam has a pressure lower than the desired pressure when leaving the compression arrangement 16, for example, lower than 5 bar, for example, 4 bar, then a compression device, such as a thermal steam recompression device, can be used to further compress the flash steam to the desired pressure, such as 5 bar. In certain embodiments, the flash steam leaving a compression device such as TVR has a pressure higher than 5 bar. The thermal steam recompression device 20 is connected to the second flash steam pipe 14 and the fresh steam pipe 3. The thermal steam recompression device compresses the flash steam by about 1 - 7 bar, more preferably 1 - 3 bar.

[0062] The compression arrangement 16 includes: one compression device 16a; two compression devices 16a, 16b connected in series, or three compression devices 16a, 16b, and 16c connected in series. In certain embodiments, when connected in series, the flash steam pipe 8 is connected to the inlet of the first compression device 16a, and the second flash steam pipe 14 is connected to the outlet of the second compression device 16b, and optionally, to the outlet of the third compression arrangement 16c. Alternatively, the flash steam pipe 8 is connected to the inlet of the compression device 16a, and the second flash steam pipe 14 is connected to the outlet of the same compression device 16a. In certain embodiments, the compression device is used in combination with another compression device connected to the second flash steam pipe, such as a thermal steam recompression device.

[0063] The compression devices 16a, 16b, and / or 16c may include a steam compressor, a heat pump, or a turbine. The turbine can transfer large volumes more efficiently. The compression devices 16a, 16b, and / or 16c may also include a turbocharger powered by the steam provided by the aforementioned control valve / steam boiler. Since the energy used to drive the turbocharger is "free", the turbocharger can further improve energy savings. As previously mentioned, the steam pressure from the steam boiler is much higher than the steam pressure required in the steam injection chamber 1. Current prior art has a steam throttle valve disposed between the boiler and the steam injection chamber. This throttle valve reduces the steam pressure from 7 - 15 bar to 4 bar, and all the high-pressure energy is lost as frictional energy in the throttle valve. When a turbocharger is used instead of the throttle valve, the high-pressure steam is directed through the drive turbine of the turbocharger, and in this way, it provides nearly free power to drive the turbocharger. In a particular embodiment, the compression device has an arrangement of a single-screw compressor type.

[0064] In some embodiments, the compression devices 16a, 16b, and / or 16c have a sanitary design. In other embodiments, when two or more compression devices are used in series, the facility is configured to provide inter-stage cooling. In some embodiments, when two or more compression devices are used in series, the two or more compression devices are connected to each other via a connection including water injection, before, inside, or after each compressor.

[0065] The compression arrangement 16 may include two compression devices of the same type, such as two steam compressors, or two compression devices of different types, such as a steam compressor and a turbine. Alternatively, the compression arrangement 16 may include three compression devices of the same type, such as three steam compressors, or three compression devices of different types, such as a steam compressor and a turbine. Additionally, inter-stage cooling may be employed after some or all of the compression devices. In a specific example, for instance, water injection may be used to cool the steam into saturated steam.

[0066] In the prior art, the first flash steam pipe 8 would be connected to the condenser pipe 11, rather than to the compression devices 16a, 16b. The condenser pipe 11 is connected to the condenser 15 and supplies the flash steam to the condenser 15. The flash steam is cooled in the condenser and then released to the atmosphere.

[0067] Without being bound by theory, it is believed that the compressor device of the present disclosure, especially when used in series, reduces the amount of energy used in the infusion system. Different from the compressor device of the present application, the currently used indirect heat pump solutions cannot provide the required energy efficiency, and the indirect heat pump cannot reduce water. Conventional indirect heat pump solutions typically have an efficiency of COP = 2 for UHT systems. Therefore, it is advantageous that the direct recompression disclosed herein has an improved efficiency of COP = 4.

[0068] The UHT facility operates by the following method. The method includes a plurality of steps performed in a continuous cycle. However, at least two of these steps are performed simultaneously. The fluid food is supplied to the steam infusion chamber 1. At the same time, fresh steam is supplied to the steam infusion chamber 1 through the first steam inlet, and flash steam is supplied through the first steam inlet or the second steam inlet, so that the fluid food is heat-treated by the fresh steam and the flash steam. After the heat treatment, the fluid food is taken out from the steam infusion chamber 1 and supplied to the flash vessel 10. After the treatment, the condensed fluid food is taken out from the lower part of the flash vessel 10. At the same time, the flash steam is removed from the upper part of the flash vessel 10. Then the flash steam is supplied to the compression arrangement 16. The compression arrangement 16 compresses the flash steam from about -0.7 bar to about 5 bar. The flash steam is incrementally compressed by two compression devices 16a, 16b connected in series. Alternatively, the flash steam is incrementally compressed by three or four compression devices 16a, 16b, 16c connected in series.

[0069] After compression, the flash steam is supplied to the steam infusion chamber 1. In one embodiment, the method further includes the step of supplying the flash steam through the hot steam recompression device 20 after the flash steam has been compressed in the compression arrangement 16 and before the flash steam is supplied to the steam infusion chamber 1.

[0070] In the following Figures 2 to 3 a specific embodiment of the compression device 16a is described, which is suitable for use in the facility for processing fluid food described herein. The advantage of this embodiment is that the compression device 16a is a high-temperature and high-pressure compressor. For the purposes of the present disclosure, the term "high-temperature compressor" is defined as a compressor having an inlet temperature of 70 - 90 °C and an outlet temperature of 120 - 170 °C after temperature reduction. In contrast, conventional mechanical compressors operate at temperatures below 50 °C. The term "high-pressure compressor" used herein refers to a compressor having a pressure ratio ("PR, pressure-ratio") in the range of 11 - 20. In contrast, conventional mechanical compressors operate with a PR less than 2.

[0071] Generally, Figure 2The compression device 16a shown in FIGS. 1 to 4 is of sterile grade and / or hygienic grade. For example, the hygienic design defines the contact surface as having a surface roughness of 0.8 - 1.2 Ra and a cleanable internal contact surface that is easy to clean in place ("CIP") without disassembly. Due to the very high speed during cleaning (> 5 m / s), the hygienic geometric design requirements (maximum radius and maximum surface roughness) are slightly lower than the 3A rules in the United States and the guidelines of the European Hygienic Engineering and Design Group ("EHEDG"), and it is still a fully CIP-cleanable compressor. Additionally, the compression device 16a may not include visible or exposed threads, bolts, and nuts in the compressor processing chamber. This contributes to the hygienic compressor design.

[0072] Although other compressible fluids, such as CO2, are considered, in the preferred embodiment, the compression device 16a is configured to compress only steam, and the compression device 16a may optionally utilize steam as an indirect medium.

[0073] Figure 2 is suitable for use in Figure 1 the UHT facility of the impeller 28 and the translucent impeller housing 29 of the compression devices 16a, 16b, and / or 16c. For the sake of brevity, the compression device 16a will be described Figures 2 to 3 , however, the compression devices 16b and / or 16c may be the same or different, and the compression arrangement 16 may include additional compression devices. As Figure 2 shown, the compression device 16a includes an inlet 30 and an outlet 31. The inlet 30 is axial, and the outlet 31 is radial. In response to the rotation of the impeller 28, the flashed steam introduced via the inlet 30 is radially accelerated. In a commonly understood manner, the radially accelerated steam is driven towards the outlet with sufficient energy so that the steam can be compressed. The compression of the steam causes a temperature rise, and thus, the energy of the flashed steam can increase so that it can be sent back to the fresh steam pipe 3 as Figure 1 shown.

[0074] As Figure 2 shown, through the blade configuration of the impeller 28, the impeller 28 is configured to function as, for example, a centrifugal high-speed compressor impeller. For the purposes of this disclosure, the term "centrifugal high-speed compressor impeller" refers to an impeller configured to rotate at greater than 20,000 revolutions per minute ("rpm"). These rotational speeds are an order of magnitude greater than those of conventional mechanical steam recompressors used in evaporators, which operate at speeds less than 3000 rpm.

[0075] In some embodiments, the compression arrangements 16a, 16b, and / or 16c are configured such that the impeller 28 rotates at a speed of 20,000 rpm to 75,000 rpm, or 35,000 rpm to 45,000 rpm, or 40,000 rpm to 42,000 rpm. The tip speed of the impeller 28 is configured to be greater than 300 meters per second ("m / s"), for example, the tip speed can be, for example, 400 - 580 m / s or preferably 450 - 550 m / s.

[0076] The compressor device of the present application has a hygienic design. Specifically, the impeller housing 29 and the impeller 28 facilitate aseptic-level cleaning and / or hygienic-level cleaning of the impeller housing 29 and the impeller 28, thereby allowing the device to be hygienic. In this regard, the impeller housing 29 can be removably fixed to the housing mounting plate 34 by a series of bolts (not shown). The housing mounting plate 34 can be part of a partition or chamber that separates the motor 32 from the food processing area. This facilitates cleaning and can extend the life of the motor 32 by reducing exposure to the cleaning fluid. The advantage of separating the motor 32 from the impeller housing 29 and the food processing area is further enhanced by the axial inlet 30 and the radial outlet 31. That is, the redirection of the steam from the axial direction to the radial direction can contribute to the ability to isolate the motor 32 from the food processing area of the UHT facility.

[0077] Figure 3 is a cross-sectional view of a compression device 16a having an impeller 28 and an impeller housing 29 according to another embodiment. Figure 3 The compression arrangement 16a shown is similar to the compression device 16a described above. Thus, for the sake of brevity, the features that have already been described will not be described again. Figure 3 The example of the impeller housing 29 shown can be fixed to the motor 32 by the back side of the housing mounting plate 34. In this way, the steam treatment side can be cleaned without the cleaning medium entering the motor compartment. In Figure 3 The cross-section of the impeller housing 29 also shows that the collection duct 36 is configured to collect the steam that is driven outwards by the rotation of the impeller 28. In Figure 3 and Figure 2 the increased cross-sectional area of the collection duct 36 is shown.

[0078] The shaft seal for the compression device 16a can include an axial seal type, where the sealing medium flows only in the axial direction. The sealing medium flows towards the processing side (impeller chamber), which is different from a conventional compressor.

[0079] It should be noted that the various contact surfaces of the compression device 16a can be configured for hygienic food contact. For example, the materials used in the impeller 28 and the impeller housing 29 can be stainless steel or other materials suitable for food contact. The surface finish can be appropriately smoothed, and the internal radius can be appropriately large to facilitate CIP operations. Additionally, internal threads, "dead legs", or pockets can be removed from the compression device 16a.

[0080] The present application has been described in connection with various embodiments herein. However, other variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, by study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The reference signs used in the claims should not be construed as limiting the scope.

[0081] It should be noted that, as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It should also be noted that the claims may be drafted to exclude any optional element. Thus, this statement is intended to serve as antecedent basis for use of exclusive terms, such as "solely", "only", etc., in connection with the recitation of claim elements, or use of a "negative" limitation.

[0082] Each of the various embodiments described and illustrated herein has discrete components and features which can be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present application. Any of the methods described herein can be performed in the order of the events recited or in any other order that is logically possible.

[0083] As used herein, when referring to a measurable value such as an amount, duration, and the like, the term "about" means encompassing a variation of ± 20% or ± 10% from the specified value, more preferably encompassing a variation of ± 5% from the specified value, even more preferably encompassing a variation of ± 1% from the specified value, and still more preferably encompassing a variation of ± 0.1% from the specified value, because such variations are suitable for performing the disclosed methods.

[0084] As used herein, the terms "comprising," "including," "containing," and "characterized by" are interchangeable, inclusive, open-ended, and do not exclude additional, unrecited elements or method steps. Any statement herein of the term "comprising," particularly in the description of the components of a composition or the elements of an apparatus, shall be understood to cover those compositions and methods consisting essentially of or consisting of the recited components or elements.

[0085] As used herein, the term "consisting of" excludes any element, step, or ingredient not specified in the claim element.

[0086] Where a numerical range is provided, it is to be understood that each intervening value, to the tenth of the unit of the lower limit (unless the context clearly dictates otherwise), between the upper and lower limits of that range and any other stated or intervening value within that stated range is covered within the application. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also covered within the application, subject to any specifically excluded limitation within the stated range. Where the stated range includes one or both of the limits, ranges excluding one or both of those included limits are also included in the application.

[0087] Many features and advantages of the present application are apparent from the detailed description, and accordingly, the appended claims are intended to cover all such features and advantages of the present application that fall within the true spirit and scope of the present application. Additionally, since many modifications and variations will readily occur to those skilled in the art, it is not desired to limit the present application to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents falling within the scope of the present application may be employed.

Claims

1. A hygienic compression device, comprising: An impeller housing having an axial inlet and a radial outlet, the axial inlet for receiving flash steam from a flash steam outlet of a food system flash vessel, and the radial outlet for supplying the compressed flash steam to a heat treatment device; An impeller disposed within the impeller housing; And A motor configured to rotate the impeller, wherein the flash steam entering the axial inlet is radially accelerated and compressed in response to the rotation of the impeller.

2. The compression device according to claim 1, wherein, The motor is configured to rotate the impeller at a speed greater than 20,000 revolutions per minute (rpm).

3. The compression device according to claim 1 or 2, wherein, The tip speed at the outer circumference of the impeller is greater than 300 meters per second (m / s).

4. The compression device according to any one of the preceding claims, wherein, The compression device is configured to produce a saturated steam temperature of 120 - 170 °C at the radial outlet.

5. The compression device according to any one of the preceding claims, wherein, The compression device is configured to produce a pressure ratio in the range of 11 - 20 at the radial outlet of the last compressor relative to the axial inlet pressure of the first compressor.

6. The compression device according to any one of the preceding claims, wherein The compression device is configured to facilitate in - place cleaning (CIP) without disassembly.

7. The compression device according to any one of the preceding claims further includes a housing mounting plate disposed between the motor and the impeller housing, wherein, The motor is isolated from the impeller and the impeller housing to facilitate aseptic hygienic cleaning of the impeller and the impeller housing without subjecting the motor to the cleaning fluid for aseptic cleaning.

8. A facility for heat - treating fluid food, having a compression device according to any one of the preceding claims.

9. The facility according to claim 8, wherein The facility includes two compression devices connected in series.

10. The facility according to claim 8, wherein, The facility includes three or four compression devices connected in series.

11. The facility according to any one of claims 8 - 10, wherein, The facility includes water injection before, inside, or after the compressors connected in series to cool the fluid food.

12. The facility according to any one of claims 8-11, wherein The steam compressor is removably attached to the facility.

13. The facility according to claim 12, wherein The steam compressor is configured to allow aseptic hygienic cleaning of the facility.

14. A method of compressing flash steam generated in an ultra - high temperature treatment facility using a heat treatment device, wherein the fluid food is heat - treated by the compressed flash steam in the heat treatment device, the method comprising: Supplying the fluid food to the heat treatment device; Supplying fresh steam and / or flash steam to the heat treatment device; Removing the fluid food from the heat treatment device; Supplying the fluid food to a flash vessel; Removing the fluid food from the flash vessel; Removing flash steam from the flash vessel; Supplying the flash steam to a hygienic compressor arrangement having a compression device, the compression device including: An impeller housing having an axial inlet and a radial outlet, the axial inlet for receiving flash steam from a flash steam outlet, and the radial outlet for supplying the compressed flash steam to a flash steam pipeline; An impeller disposed within the impeller housing; and A motor configured to rotate the impeller, wherein the flash steam entering the axial inlet is radially accelerated and compressed in response to the rotation of the impeller; and the hygienic compressor arrangement compresses the flash steam and then supplies the flash steam to the heat treatment device.

15. The method according to claim 14, wherein, The ultra - high temperature treatment facility includes two compression devices arranged in series, and the flash steam is incrementally compressed by the two compression devices.

16. The method according to claim 14, wherein, The ultra-high temperature treatment facility includes three or four compression devices arranged in series, and the flash steam is incrementally compressed by the three or four compression devices.

17. The method according to claim 15 or 16, further comprising cooling before, inside or after the compression devices arranged in series.

18. The method according to claim 17, wherein, The cooling includes water injection cooling or cooling through a heat exchanger.

19. The method according to claim 14, wherein, The compression device is cleaned by separately cleaning the impeller and the impeller housing on-site, without cleaning the motor.

20. A facility for heat-treating fluid food, the facility comprising: A heat treatment device (1) having a fluid food inlet arranged at the top of the heat treatment device (1); A fluid food outlet arranged at the bottom of the heat treatment device (1); And A first steam inlet arranged at the top of the heat treatment device (1) for heat-treating the fluid food by supplying fresh steam and / or flash steam into the heat treatment device (1), the fresh steam being supplied into the heat treatment device (1) through a fresh steam pipe (3) connected to the first steam inlet, a flash vessel (10) having a fluid food inlet at the top of the flash vessel (10) and a fluid food outlet at the bottom of the flash vessel (10), the fluid food outlet of the heat treatment device (1) being connected to the fluid food inlet of the flash vessel (10) through a pipe (9) and a pump (6), the fluid food outlet of the flash vessel (10) being connected to a pipe (12) and a pump (13) for discharging the fluid food from the flash vessel (10), the flash vessel (10) further including a flash steam outlet arranged at the top of the flash vessel (10), the flash steam outlet being connected to a first flash steam pipe (8), the first flash steam pipe (8) being connected to the inlet of a compression arrangement (16), the first flash steam pipe (8) being adapted to supply the flash steam to the compression arrangement (16) where the flash steam is compressed, a second flash steam pipe (14) being connected to the outlet of the compression arrangement (16), the second flash steam pipe (14) being adapted to transfer the flash steam to the heat treatment device (1), wherein the compression arrangement includes: An impeller housing having an axial inlet and a radial outlet, the axial inlet for receiving flash steam from the flash steam outlet and the radial outlet for supplying compressed flash steam to the second flash steam pipe; An impeller arranged in the impeller housing; A motor configured to rotate the impeller, wherein the flash steam entering the axial inlet is radially accelerated and compressed in response to the rotation of the impeller; and A hygienic cleanable compressor arrangement.

21. The facility according to claim 20, wherein, The compression device further includes a housing mounting plate arranged between the motor and the impeller housing, wherein the motor is isolated from the impeller and the impeller housing to facilitate aseptic cleaning of the impeller and the impeller housing without subjecting the motor to the cleaning fluid for the aseptic cleaning.

22. The facility according to claim 20 or 21, wherein, The impeller housing and the impeller are cleaned independently of the motor by performing a hygienic cleaning of the impeller housing and the impeller.

23. The facility according to claim 20 or 21, wherein The compression arrangement further comprises a plurality of compression means.

24. The installation according to any one of claims 20 to 23, further comprising a water injection device arranged before, inside or after the compression means in order to cool the compressed flash steam.

25. The installation according to any one of claims 20 to 24, further comprising a sterile design for UHT sterilized food products.

Images