Device and method for high-pressure treatment of a liquid

Abstract

A device (1) for the high-pressure treatment of a liquid comprises a compression head (2), a housing (11) fastened to the compression head (2), at least one working plunger arrangement (3) arranged in the housing (11) with a working chamber (31) and an axially movable working plunger (32) delimiting the working chamber (31), a valve body (4) arranged between the compression head (2) and the housing (11) and adjoining the working chamber (31), said valve body having a through-channel (41) and a suction channel (42) closable by a closing body (43), at least one outlet valve (5) fastened to the compression head (2) with an outlet (53) closable by a closing body (51), wherein the through-channel (41) of the valve body (4) opens into a compression chamber (22) of the compression head (2), wherein at least one additional plunger arrangement (6) is attached,wherein the at least one additional plunger arrangement (6) has a working chamber (61) fluidly connected to the working chamber (22) of the compression head (2) and an axially movable, spring-loaded additional plunger (62) delimiting the working chamber (61), with which the working chamber (61) of the additional plunger arrangement (6) can be adjusted to a predetermined volume. Furthermore, a method for the high-pressure treatment of a liquid is described.

Description

[0001] The present invention relates to a device for the high-pressure treatment of a liquid according to the preamble of claim 1.

[0002] The invention further relates to a method for the high-pressure treatment of a liquid.

[0003] The areas of application of the high-pressure treatment of liquids described below are, for example, preservation, typically the preservation of food, or conversion, i.e. the chemical or biological structural change of liquids, for example the denaturation of proteins.

[0004] Various physical processes such as pasteurization or sterilization are known for preserving food by applying high pressure.

[0005] While pasteurization of food preserves the vitamins, sterilization kills all germs but also destroys the vitamins.

[0006] Conventional pasteurization processes use, among other things, high temperatures to kill germs and bacteria, ensuring long-term storage life for food. Pasteurization with heat treatment has the advantage of being able to implement a continuous industrial process.

[0007] The problem with this type of pasteurization is that the high temperatures also destroy vitamins contained in the food.

[0008] In addition, high-pressure pasteurization (HPP) has gained increasing importance in recent years. This type of pasteurization allows all types of food to be preserved using extremely high pressure while preserving vitamins. Both solid and liquid foods are exposed to water pressures of 2,000 to 6,000 bar in their final packaging in a high-pressure chamber.

[0009] The disadvantage of this type of pasteurization is that a continuous production process cannot be realized, since the high-pressure chambers must first be loaded, flooded with water, the high pressure realized, the high pressure released and the food then removed again.

[0010] High-pressure plunger pumps can be used to generate the necessary high pressure. A high-pressure plunger pump of this type, known, for example, from DE 10 2016 124 422 A1, has one or more oscillating plungers. Each plunger draws a volume of fluid into a working chamber of the plunger pump via a control valve designed as a suction valve and discharges it under high pressure through an outlet valve. The plunger is driven by a drive shaft driven by a drive device, for example, an electric motor.

[0011] The object of the present invention is to provide a device with which a high-pressure treatment of liquids, in particular the preservation of liquid foodstuffs, is made possible with reduced energy consumption and with reduced time expenditure.

[0012] Another object of the present invention is to provide a method for high-pressure treatment of a liquid using the device.

[0013] The first object is achieved by a device for high-pressure treatment of a liquid having the features of claim 1.

[0014] The second object is further achieved by a method for high-pressure treatment having the features of claim 16.

[0015] The device according to the invention comprises a compression head with a compression chamber, a housing fastened to the compression head and at least one working plunger arrangement arranged in the housing with a working chamber and a working plunger delimiting the working chamber and arranged axially movable in a working plunger housing.

[0016] The device further comprises at least one inlet valve attached to the compression head with an inlet that can be blocked by a closing body.

[0017] Furthermore, at least one outlet valve with an outlet that can be blocked by a closing body is attached to the compression head.

[0018] At least one additional plunger assembly is attached to the compression head.

[0019] This at least one additional plunger arrangement has a working chamber fluidically connected to the compression chamber of the compression head and an additional plunger which delimits the working chamber and is arranged to be axially movable in an additional plunger housing, with which the working chamber of the additional plunger arrangement can be adjusted to a volume which determines a maximum pressure in the compression chamber filled with the liquid.

[0020] With such a device according to the invention, it is possible to preserve liquids, in particular liquid foodstuffs, for example orange juice, within a continuous production process, in particular to pasteurize or sterilize them, without significantly increasing the temperature of the liquid foodstuff.

[0021] In addition, a particularly economical production process is made possible because the energy introduced into the liquid food after pressurization in the pressure stroke drives the working plunger of the device as relief energy in a subsequent relief stroke of the working plunger.

[0022] Advantageous embodiments of the invention are the subject of the subclaims.

[0023] According to an advantageous embodiment, the additional plunger arrangement has an actuating unit directly coupled to the additional plunger, with which the volume of the working space of the additional plunger arrangement required to set the maximum pressure can be adjusted by positioning the additional plunger.

[0024] The additional plunger can preferably be controlled by a control unit accommodated in a housing of the actuating unit

[0025] In an advantageous further development, the additional plunger arrangement has an actuating unit with an actuating element with which the volume of the working space of the additional plunger arrangement required to set the maximum pressure can be adjusted by limiting a deflection of the additional plunger to a predetermined amount.

[0026] This makes it easy to set different operating pressures for the high-pressure treatment process.

[0027] According to an advantageous development, the actuating element is designed as a travel adjustment unit. Pneumatic, electrical, or hydraulic adjustment of the actuating element is conceivable.

[0028] In a preferred embodiment, the travel adjustment unit is designed as an adjusting screw.

[0029] The additional plunger is preferably spring-loaded by an energy accumulator accommodated in a housing of the actuating unit, preferably in the form of a compression spring.

[0030] According to an alternative design variant, the travel adjustment unit is designed as a linear actuator directly coupled to the additional plunger.

[0031] According to a further alternative design variant, the additional plunger can be controlled by a control unit accommodated in a housing of the actuating unit.

[0032] According to a preferred development of the invention, the additional plunger is coupled to the compression spring via a pressure piston.

[0033] According to an advantageous design variant, the outlet valve can be controlled pneumatically, electrically or hydraulically.

[0034] A control of the outlet valve is preferably designed such that an opening of the outlet valve can be controlled after one working stroke of the working plunger or a plurality of working strokes of the working plunger.

[0035] According to one embodiment, the at least one inlet valve is integrated into a valve body arranged between the compression head and the housing. The valve body has a through-channel adjoining the working chamber and opening into the compression chamber of the compression head, as well as a suction channel that can be closed with a closing body. The suction channel, together with the closing body, forms the inlet valve.

[0036] According to a preferred alternative embodiment, the at least one inlet valve is attached to the compression head as a separate component.

[0037] The design of the inlet valve as a separate component on the compression head enables particularly easy cleaning of all media-exposed components of the device.

[0038] According to a preferred embodiment, the working plunger, the additional plunger and a respective sealing bushing receiving the latter are made of hard metal or ceramic.

[0039] The method according to the invention for the high-pressure treatment of a liquid foodstuff using a device as described above comprises the following method steps: In a first method step a), the working chamber of the working plunger is filled with the liquid through the open inlet valve in a suction stroke of the working plunger with the outlet valve closed and with the working chamber of the additional plunger arrangement minimized in an initial position of the additional plunger.

[0040] Subsequently, in a method step b), a compression phase is initiated in the pressure stroke of the working plunger with the outlet valve and suction channel closed, wherein the additional plunger is pressed by the liquid from the starting position into a position that enlarges the working space of the additional plunger arrangement and wherein at least in a final phase of the pressure stroke of the working plunger, the liquid is under maximum pressure due to a counterforce exerted on the liquid by the additional plunger.

[0041] Thereafter, in a process step c), a decompression phase is initiated in the subsequent suction stroke of the working plunger with the outlet valve and suction channel closed, whereby the working plunger is moved by the expansion energy of the compressed liquid food and the spring-loaded additional plunger is pushed back into the starting position minimizing the working space of the additional plunger arrangement by the spring force.

[0042] Finally, the outlet valve opens and the liquid, high-pressure treated food is pushed out in the conveying stroke of the working plunger.

[0043] Optionally, process steps b) and c) can be repeated once or several times to increase the pressurised residence time of the liquid food, while realising moderate pressures up to preferably 4500 bar.

[0044] In a first further development, the additional plunger is pressed against the adjusting element in process step b) to adjust the volume of the working space of the additional plunger arrangement required to reach the maximum pressure.

[0045] In an alternative development, the additional plunger in process step b) is initially held in the starting position by the force of the energy accumulator, wherein the energy accumulator is set in such a way that the liquid is compressed to the volume required to reach the maximum pressure immediately after initiation of the pressure stroke of the working plunger and in the further pressure stroke of the working plunger, when the force of the energy accumulator is exceeded, the additional plunger is pushed away from its starting position.

[0046] Preferred embodiments are explained in more detail below with reference to the accompanying drawings. They show: Fig. 1 and Fig. 2 schematic isometric representations of a first embodiment of a device according to the invention, Fig. 3 a sectional view through the device according to Fig. 1 showing a working plunger arrangement, compression head mounted thereon and outlet valve and additional plunger arrangement attached thereto, Fig. 4 an enlarged detail of the compression head area of ​​the Fig. 2 shown illustration, Fig. 5 to 7 schematic sectional views of various variants of the additional plunger arrangement, Fig. 8 a schematic isometric representation of an alternative embodiment of a device according to the invention, Fig. 9 one of the Fig. 4 corresponding enlarged detail of the area of ​​the alternative compression head in a sectional view through the device according to Fig. 8, Fig. 10 one of the Fig. 4 corresponding enlarged detail of the area of ​​a further alternative embodiment of the device with controlled inlet valve in a sectional view through the device according to Fig. 8, Fig. 11 to 18 are schematic diagrams explaining the high-pressure treatment process, Fig. 19 a schematic diagram showing possible pressure curves in the compression chamber depending on the crankshaft coupled to the working plunger and Fig. 20 a schematic diagram showing possible volume curves of the total compression chamber depending on the crankshaft coupled to the working plunger.

[0047] In the following description of the figures, terms such as top, bottom, left, right, front, rear, etc., refer exclusively to the exemplary representation and position of the device, working plunger, additional plunger, working chamber, valve body, outlet valve, actuating unit, and the like chosen in the respective figures. These terms are not to be understood as limiting; i.e., these references may change due to different working positions or the mirror-symmetrical design, etc.

[0048] In the Fig. 1 to 3 and in Fig. 8, the reference numeral 1 denotes embodiments of a device according to the invention.

[0049] In all variants, the device 1 comprises a compression head 2 with a compression chamber 22 and a housing 11 fastened to the compression head 2, in which at least one working plunger arrangement 3 is arranged.

[0050] The working plunger arrangement 3 has in all variants, as shown in the Fig. 3, Fig. 4, Fig. 9 and Fig. 10, a working chamber 31 and a working plunger 32 which delimits the working chamber 31 and is arranged to be axially movable in a plunger housing 33 and which is connected to a drive shaft 13 driven by a motor, for example an electric motor, shown in Fig. 3, is coupled.

[0051] The drive shaft 13 is surrounded by a housing 12 of the device 1. The axial movement of the working plunger 32 takes place axially to the longitudinal axis A AP of the working plunger 32, in the Fig. 1 to 3, 8 and 9 in z-direction.

[0052] How to continue in the Fig. 3 and Fig. 4, at least one valve body 4 is arranged between the compression head 2 and the housing 11, adjoining the working chamber 31, with a through-channel 41 designed here as a pressure channel and a suction channel 42 closable by a closing body 43. The liquid to be treated under high pressure, in particular a liquid foodstuff, is introduced into the working chamber 31 through the suction channel 42. In this first embodiment, the suction channel 42 and the closing body 43 form an inlet valve 9' for introducing the liquid to be treated, for example, to be pasteurized under high pressure, into the compression chamber 22.

[0053] In the illustrated embodiment, the closing body 43 is designed as a cone that holds the suction channel 42 at its opening into the working chamber 31 of the working plunger assembly 3. During the suction stroke of the working plunger 32, when the working chamber 31 is not filled with liquid food, the cone is pushed away from the opening of the suction channel 42 by the pressure of the liquid food supplied to the suction channel 42 from outside.

[0054] If the working chamber 31 of the working plunger arrangement 3 is filled with the liquid, this presses the closing body 43 against the mouth of the suction channel 42 and thus closes the suction channel 42.

[0055] The valve body 4 can be provided with one suction channel 42 or with several suction channels 42, each of which is assigned a closing body 43. The suction channel 42, together with the closing body 43, forms the inlet valve 9', which is designed here as a suction valve.

[0056] In the Fig. In the embodiments of the device 1 shown in Figures 8 to 10, the at least one inlet valve 9 is mounted as a separate component on the compression head 2, in the embodiment shown opposite the working chamber 31 of the working plunger arrangement 3.

[0057] The coupling of the working plunger arrangement 3 to the compression head 2 is effected here via a simpler valve body 4 with a through channel 41 for connecting the working chamber 31 to the compression chamber 22 of the compression head 2, but without a suction channel 42 and closing body 43.

[0058] The inlet valve 9 has the Fig. The embodiments shown in Figures 8 to 10 comprise a closing body 91, which serves to close an inlet 93. The closing body 91 is accommodated in a housing 94. The housing 94 further has a passage 92 for connection to the compression chamber 22 of the compression head 2.

[0059] On its side facing away from the inlet 93, the closing body 91 in the embodiment according to Fig. 8 and Fig. 9 is loaded by a compression spring to allow the liquid food to flow in only when pressure acts from the inlet on the closing body 91.

[0060] In the alternative design variant according to Fig. 10, the inlet valve 9 is designed as a controllable inlet valve, analogous to the outlet valve 5 described in more detail below.

[0061] Furthermore, in all embodiments of the device 1, at least one outlet valve 5 is attached to the compression conf 2.

[0062] The outlet valve 5 has an outlet 53 which can be blocked by a closing body 51 and through which the high-pressure treated liquid food is discharged from the device 1 at the end of the high-pressure treatment process.

[0063] The outlet valve 5 can preferably be controlled pneumatically, electrically or hydraulically.

[0064] The through-channel 41 of the valve body 4 opens into a compression chamber 22 of the compression head 2, which leads firstly to the outlet valve 5 and secondly to an additional plunger arrangement 6 fastened to the compression head 2.

[0065] In the Fig. 1, Fig. 2 and Fig. In the embodiments shown in Figure 8, a total of three outlet valves 5 and correspondingly three additional plunger arrangements 6 are fixed to the compression head 2. Depending on the capacity requirements, more or fewer outlet valves 5 and additional plunger arrangements 6 are also conceivable, which are fixed to a correspondingly designed compression head 2.

[0066] In the Fig. 5 to 7 show different design variants of the additional plunger arrangements 6.

[0067] Common to all design variants of the additional plunger arrangements 6 is a working chamber 61 fluidically connected to the working chamber 22 of the compression head 2 and an additional plunger 62 which delimits the working chamber 61 and is arranged to be axially movable.

[0068] The variable working chamber 61 of the additional plunger 62 forms together with the compression chamber 22 of the compression head 2 a total compression chamber 15 (shown in the schematic diagrams to explain the high-pressure treatment process of the Fig. 11 to 18), to which the liquid is compressible in a pressure stroke of the working plunger 32 of the working plunger arrangement 3 and which has a maximum pressure p max the liquid is defined.

[0069] While in the Fig. 5 and Fig. 7 shown embodiments of the additional plunger arrangement 6, the working chamber 61 of the additional plunger arrangement 6 by a stop to a predetermined, the maximum pressure p maxThe maximum volume defining the liquid can be adjusted. Fig. 6 shown variant of the additional plunger arrangement 6 the maximum pressure p max the liquid is defined exclusively by the spring constant of a force accumulator 66.

[0070] In the Fig. 5 and Fig. In the embodiments shown in Fig. 7, the additional plunger arrangement 6 has an actuating unit 63 with an actuating element 64 for setting a predetermined volume of the working chamber 61 required for pressure generation.

[0071] The adjusting element limits the deflection of the additional plunger 62 in the axial direction A ZP to a predetermined level. The adjusting element is preferably designed as a travel adjustment unit.

[0072] At the Fig. 6, an actuating unit 63 with an actuating element 64 is also present, which here serves to adjust the spring constant of the energy accumulator 66.

[0073] In the Fig. 5 and Fig. In the preferred embodiment of the additional plunger assembly 6 shown in Figure 6, the adjusting element 64 is designed as an adjusting screw. The adjusting screw is screwed into an internal thread of a housing 69 of the adjusting unit 63.

[0074] It is also conceivable, as in Fig. 7, the travel adjustment unit, here the actuating element 64, is designed as a linear actuator directly coupled to the additional plunger 62.

[0075] The additional plunger 62 can preferably be controlled by a control unit accommodated in a housing of the actuating unit 63.

[0076] How to continue in Fig. 5, an end 642 remote from a screw head 641 of the adjusting screw projects into a cavity 691 of the housing 69 of the adjusting unit 63. This end 642 serves as a stop for the additional plunger 62.

[0077] At the Fig. 5, in the cavity 691 of the housing 69, a ZP A movable piston 65 and a force accumulator 66 loading the piston 65 are mounted. The force accumulator 66 pushes the piston away from the end 642 of the adjusting screw.

[0078] A first end of the additional plunger 62 is fixed to the end of the piston 65 facing away from the energy accumulator 66. The energy accumulator 66 is, as shown in the Fig. 3 to 6, 9 and 10, preferably designed as a compression spring.

[0079] The penetration depth of the adjusting screw into the cavity 691 of the housing 69, ie in the axial direction A ZPThe considered position of the end 642 of the adjusting element 64 designed as an adjusting screw can be easily adjusted by the screw head 641.

[0080] Also in the Fig. In the embodiment shown in Figure 5, the spring constant of the energy accumulator 66 causes a compression of the volume of the liquid, increasing the pressure of the liquid.

[0081] The spring constant of the energy accumulator 66 is dimensioned in this design variant so that the maximum pressure p max the liquid is only reached after the additional piston 62 hits the end 642 of the actuating element 64.

[0082] How to continue in the Fig. As shown in Figures 4 to 7, 9, and 10, the additional plunger 62 is guided in a plunger guide 68 adjoining the actuating unit 63. The plunger guide is attached, in particular screwed, to the compression head 2 together with a guide housing 67.

[0083] In the transition area between the compression head 2 and the guide housing 67, a first coupling piece 7 with a passage 71 for the liquid between the compression chamber 22 of the compression head 2 and the working chamber 61 of the additional plunger arrangement 6 is preferably provided.

[0084] Furthermore, a second coupling piece 8 with a passage 81 for the liquid between the compression chamber 22 of the compression head 2 and the outlet 53 of the outlet valve 5 is preferably provided between the compression head 2 and a housing 54 of the outlet valve 5.

[0085] The working plunger 32, the additional plunger 62 and a respective sealing bush 14 receiving it, in the Fig. 3, Fig. 4, Fig. 9 and Fig. 10 are preferably made of hard metal or ceramic.

[0086] Based on the Fig. 11 to 18, a method for the high-pressure treatment of a liquid, in particular a liquid food, with a device 1 as described above is described below.

[0087] The procedure can be as described in the Fig. 19 and Fig. 20 can be divided into four phases based on a pressure curve (depending on the crankshaft position of the crankshaft coupled to the working plunger(s)) or volume curve: a) Suction of the liquid (suction stroke), b) Compressing the liquid (pressure stroke), c) Decompression of the fluid (relaxation stroke) and d) Ejection of the liquid (discharge stroke).

[0088] Fig. 11 schematically shows a position of the working plunger 32 shortly after the start of a suction stroke, in which in a method step a) a total compression chamber 15 is filled with a quantity of the liquid to be treated corresponding to the volume of the working chamber 31 of the working plunger arrangement 3 through the opened inlet valve 9, 9'.

[0089] The suction stroke described here represents a suction stroke during which the compression chamber 22 itself is already or still filled with the liquid. During initial filling, the volume defined by the compression chamber 22 must also be filled with the liquid.

[0090] During this first work step, the outlet valve 5 is closed. The additional plunger 62 is in its position minimizing the working chamber 61 of the additional plunger assembly 6 with the compression spring 66 relaxed. The intake stroke is completed when the bottom dead center (UT) is reached.

[0091] Fig. 12 schematically shows a position of the working plunger 32 shortly after the start of a pressure stroke (first pressure stroke phase b1)), after the working plunger 32 has passed the bottom dead center, at which the filling of the working chamber 31 with the liquid to be treated is completed.

[0092] During the pressure stroke phase b2), the additional plunger reaches its maximum volumetric released end position of the working chamber 61, as shown in the figure.

[0093] As soon as the additional plunger 61 has reached its end position, the volume in the total compression chamber 15 is compressed and changed exclusively via the pressure stroke of the working plunger 32 until the pressure stroke phase b3) at the top dead center TDC, shown in Fig. 14, is completed.

[0094] At the Fig. In the variant of the additional plunger arrangement 6 shown in Figure 6, the release of the volume-maximizing total compression chamber 15 extends over the entire pressure stroke phase. The corresponding volume or pressure curve in the total compression chamber 15 is shown in the Fig. 19 and Fig. 20 represented by the dashed line.

[0095] Preferably, the pressure is increased to a pressure of 2000 bar to 8000 bar, particularly preferably to a pressure of 4000 bar to 5000 bar. The compression chamber 22 and the working chambers 31, 61 opened by the working plunger 32 and the additional plunger 62 form the overall compression chamber 15.

[0096] After reaching the Fig. 14 shown top dead center of the working plunger 32, in a process step c) a Fig. 15 and Fig. 16 is initiated in the subsequent relief stroke of the working plunger 32 with the outlet valve 5 closed and the suction channel 42 or the inlet valve 9 closed.

[0097] In the Fig. During the relief stroke phase c1) shown in Figure 15, the additional plunger initially remains in the end position until the spring force acting on the additional plunger exceeds the reducing pressure force. The spring force pushes the additional plunger 62, as shown in Fig. 16, in a relief stroke phase c2) back into the volume-minimizing starting position of the working space.

[0098] During the relief stroke, the working plunger 32 is driven by the relaxation energy of the compressed fluid.

[0099] The drive of the working plunger 32 is supported by the expansion energy of the liquid food compressed during the compression stroke. The spring-loaded auxiliary plunger 62 is pushed back into the initial position, minimizing the working chamber 61 of the auxiliary plunger assembly 6, by the spring force of the spring element 66.

[0100] If the outlet valve 5 remains closed after the relief stroke, the above-described process steps b) and c) are repeated once or several times in an optional process step e). The alternating pressure applied to the fluid during the rapid pressure and relief stroke further increases the intensity of the high-pressure treatment on the fluid.

[0101] In a process step d), shown in Fig. 17), finally, a quantity of the treated liquid corresponding to the working chamber 31 of the working plunger 32 is pushed out without pressure from the compression chamber in a subsequent delivery stroke of the working plunger 32 with the outlet valve 5 open and the inlet valve 9, 9' closed.

[0102] The rotating additional plunger 62 ensures that the entire stroke volume of the working plunger can always be pumped.

[0103] The one in Fig. The volume and pressure curve in the overall compression chamber 15 shown in Figure 5 for the variant of the additional plunger arrangement 6 is shown in the Fig. 19 and Fig. 20 represented by the solid line.

[0104] A control of the outlet valve 5 is accordingly preferably designed such that an opening of the outlet valve 5 can be controlled after a working stroke of the working plunger 32 or a plurality of working strokes of the working plunger 32. List of reference symbols 1 device 2 compression head 21 Valve accommodation space 22 Compression chamber 3 Working plunger arrangement 31 work space 32 working plungers 33 Working plunger housing 4 valve bodies 41 Through channel 42 suction channel 43 locking bodies 5 Exhaust valve 51 locking body 52 pistons 53 Outlet 54 housings 6 Additional plunger arrangement 61 workspace 62 additional plungers 63 Actuator 64 Control element 641 screw head 642 End 65 pressure pistons 66 compression spring 67 Additional plunger housing 68 Plunger guide 69 housings 691 Cavity 7 first coupling piece 71 Passage 8 second coupling piece 81 Passage 9, 9' intake valve 91 locking body 92 passage 93 Entrance 94 housings 11 housings 12 housings 13 Drive shaft 14 socket 15 Total compression space 16 Starting position 17 Final position X direction Y direction Z direction A AP Movement axis working plunger A ZP Movement axis additional plunger QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 124 422 A1

[0010]

Claims

[1] Device (1) for high-pressure treatment of a liquid, comprising - a compression head (2) with a compression chamber (22), - a housing (11) attached to the compression head (2), - at least one working plunger arrangement (3) arranged in the housing (11) with a working chamber (31) and a working plunger (32) delimiting the working chamber (31) and arranged axially movable in a working plunger housing (33), - at least one inlet valve (9, 9') attached to the compression head (2) with an inlet (93, 42) which can be blocked by a closing body (91, 43), - at least one outlet valve (5) attached to the compression head (2) with an outlet (53) which can be blocked by a closing body (51), characterized by , that - at least one additional plunger arrangement (6) is attached to the compression head (2), - wherein the at least one additional plunger arrangement (6) has a working chamber (61) fluidically connected to the compression chamber (22) of the compression head (2) and an additional plunger (62) which delimits the working chamber (61) and is arranged to be axially movable in an additional plunger housing (67), with which the working chamber (61) of the additional plunger arrangement (6) can be adjusted to a volume which has a maximum pressure (p max ) in the compression chamber (22) filled with the liquid. [2] Device (1) according to claim 1, characterized by that the additional plunger arrangement (6) has an actuating unit directly coupled to the additional plunger (62), with which the pressure required to set the maximum pressure (p max ) required volume of the working space (61) of the additional plunger arrangement (6) can be adjusted by positioning the additional plunger (62). [3] Device (1) according to claim 2, characterized bythat the additional plunger (62) can be controlled by a control unit accommodated in a housing of the actuating unit. [4] Device (1) according to claim 1, characterized by that the additional plunger arrangement (6) has an actuating unit (63) with an actuating element (64) with which the pressure required to set the maximum pressure (p max ) required volume of the working space (61) of the additional plunger arrangement (6) can be adjusted by limiting a deflection of the additional plunger (62) to a predetermined amount. [5] Device (1) according to claim 3 or 4, characterized by that the adjusting element (64) is designed as a travel adjusting unit. [6] Device (1) according to claim 5, characterized by that the travel adjustment unit is designed as a linear actuator directly coupled to the additional plunger (62). [7] Device (1) according to claim 5, characterized by that the travel adjustment unit is designed as an adjusting screw. [8] Device (1) according to claim 4 to 7, characterized by that the additional plunger (62) is spring-loaded by a force accumulator (66) accommodated in a housing of the actuating unit (63). [9] Device (1) according to claim 8, characterized by that the energy accumulator (66) is designed as a compression spring. [10] Device (1) according to claim 8 or 9, characterized by that the additional plunger (62) is coupled to the energy accumulator (66) via a pressure piston (65). [11] Device (1) according to one of the preceding claims, characterized by that the outlet valve (5) can be controlled pneumatically, electrically or hydraulically. [12] Device (1) according to one of the preceding claims, characterized by that a control of the outlet valve (5) is designed such that an opening of the outlet valve (5) can be controlled after one working stroke of the working plunger (32) or a plurality of working strokes of the working plunger (32). [13] Device (1) according to one of the preceding claims, characterized by that the at least one inlet valve (9) is attached to the compression head (2) as a separate component. [14] Device (1) according to one of the preceding claims, characterized by that the working plunger (32), the additional plunger (62) and a respective sealing bushing (14) receiving the latter are made of hard metal or ceramic. [15] Device (1) according to one of the preceding claims, characterized by in that the at least one inlet valve (9') is integrated into a valve body (4) which is arranged between the compression head (2) and the housing (11) and has a through-channel (41) adjoining the working chamber (31) and opening into the compression chamber (22) of the compression head (2), as well as a suction channel (42) which can be closed by a closing body (43), the suction channel (42) together with the closing body (43) forming the inlet valve (9'). [16] Method for the high-pressure treatment of a liquid with a device (1) according to one of the preceding claims, comprising the method steps: a) filling the working chamber (32) with the liquid through the open inlet valve (9, 9') in a suction stroke of the working plunger (32) with the outlet valve (5) closed and with the working chamber (61) of the additional plunger arrangement (6) minimized in an initial position of the additional plunger (62), b) initiating a compression phase in a pressure stroke of the working plunger (32) with the outlet valve (5) and the suction channel (42) closed, wherein the additional plunger (62) is pressed by the liquid from the initial position into a position enlarging the working space (61) of the additional plunger arrangement (6), and wherein at least in a final phase of the pressure stroke of the working plunger (32), the liquid is pressurised to maximum pressure (pmax ) stands, c) initiating a decompression phase in a subsequent relief stroke of the working plunger (32) with the outlet valve (5) and the suction channel (42) closed, wherein the relief stroke of the working plunger (32) is moved with the support of the expansion energy of the compressed liquid and the additional plunger (62) is moved back into the initial position which minimizes the volume of the working chamber (61) of the additional plunger arrangement (6), d) Opening the outlet valve (5) and pushing out the liquid in one delivery stroke of the working plunger (32). [17] Method according to claim 16, characterized by that after process step c) and before process step d) process steps b) and c) are repeated once or several times. [18] Method according to claim 16 or 17, characterized bythat the additional plunger (62) in process step b) against the adjusting element (64) for setting the pressure required to reach the maximum pressure (p max ) required volume of the working space (61) of the additional plunger arrangement (6) is pressed. [19] Method according to claim 16 or 17, characterized by that the additional plunger (62) is initially held in its initial position in process step b) by the force of the energy accumulator (66), wherein the energy accumulator (66) is adjusted so that the liquid is immediately pressurized to the pressure required to reach the maximum pressure (p max ) required volume is compressed and in the further pressure stroke of the working plunger (32) when the force of the energy accumulator (66) is exceeded, the additional plunger (62) is pushed away from its initial position.

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