Centrifuge and method for operating same

Abstract

The present invention relates to a centrifuge (1) for separating or washing a flowable product or a flowable suspension into at least two phases in a continuous operation, the centrifuge having a rotatably mounted drum (2) driven by a drive motor, with a drum shell made of metal and a rotating shaft (3), the drum (2) having a feed pipe (4) and at least one gripper chamber (5) with a paring disc (8) for discharging the washed or separated liquid, preferably solid discharge. The drum (2) has at least two axially superimposed sealing chambers (7, 12) above the gripper chamber (5), each sealing chamber (7, 12) having a sealing disc (9, 14) protruding into the respective sealing chamber (7, 12), and at least one supply channel (11, 11') is provided for supplying sealing medium (32) to one of the sealing chambers (7, 12), or at least one supply channel (11, 11') is provided for supplying sealing medium (32) to the respective sealing chamber (7, 12).

Description

[Technical field]

[0001] The present invention relates to a centrifuge according to the preamble of claim 1 and to a method for operating said centrifuge according to claim 13. [Background technology]

[0002] Centrifuges (especially separators) that process products that change their properties when in contact with oxygen must be sealed against the oxygen-containing atmosphere and to ensure that gases dissolved in the product are retained intact in the product, as is desirable, for example, in the centrifugal purification of beer.

[0003] In such centrifuges, one or more liquid phases are often withdrawn through an outlet where a so-called stationary gripper is arranged. The gripper (also called a pulping disk) works according to the principle of a centripetal pump.

[0004] In the drum of such a centrifuge there is a so-called sealing disk in the head, which is surrounded by a rotating chamber. The chamber is filled with a sealing liquid in which the sealing disk is immersed and in which a siphon-like seal is formed. This seals the gripper and the drum chamber from contact with the surrounding atmosphere. Such a construction is known from German Offenlegungsschrift 196 31 226. Nevertheless, with this simple seal a certain amount of oxygen absorption is still observed, since part of the oxygen diffuses through the sealing liquid. This effect also occurs with deaerated water. For this reason, current centrifuges need to additionally displace the oxygen atmosphere above the rotating sealing chamber or airtight chamber by means of an inert gas such as CO2.

[0005] Furthermore, so-called fully sealed centrifuges are known in which the rotor is sealed against the atmosphere with shaft and mechanical seals. Furthermore, the area of ​​the sealing points is pressurized so that oxygen cannot penetrate from the outside, as described, for example, in US Pat. No. 3,126,338. These sealing systems are rather expensive, require a lot of maintenance, and are vulnerable, for example, to imbalances and discharge pulses. If the seal is lost, undesirable oxygen can enter the rotating system of the centrifuge. Summary of the Invention [Problem to be solved by the invention]

[0006] Based on the above prior art, it is an object of the present invention to provide a centrifuge and a method for operating said centrifuge, which provides improved sealing of the product in the drum against an oxygen-rich atmosphere. [Means for solving the problem]

[0007] The present invention solves this object by a centrifuge having the features of claim 1. A centrifuge is thus provided for separating or purifying a flowable product or a flowable suspension into at least two phases in a centrifugal field in a continuous operation, the centrifuge having a rotatably mounted drum, the drum being driven by a drive motor and having a drum shell made of metal with a vertical axis of rotation, the drum further comprising a feed pipe and at least one gripper chamber, the gripper chamber being provided with a gripper for discharging the purified or separated liquid and preferably solid discharges, the drum comprising at least two axially superimposed sealing chambers above the gripper chamber, each sealing chamber having a sealing disc projecting into the respective sealing chamber, at least one feed channel is provided for supplying a sealing medium to one sealing chamber or at least one feed channel is provided for supplying a sealing medium to each sealing chamber.

[0008] This creates a very good pseudo double "fluid-tight" sealed drum.

[0009] The centrifuge according to the invention is more robust than centrifuges constructed to be completely airtight, since there are no mechanical seals which are subject to wear.

[0010] According to a particularly preferred variant, lines are provided in particular for feeding gas into the annular space around an intermediate annular wall extending radially inwards from the drum shell between the two sealing chambers, or for evacuating gas from the annular space.

[0011] According to one variant, it is then further preferred that a discharge line is provided for discharging the gas from the annular space.

[0012] A sealing gas, preferably heavier than air, is introduced into the annular space between the two sealing discs. During operation of the centrifuge, the sealing gas, preferably heavier than air, is then located in the annular space between the two sealing discs.

[0013] This produces a centrifuge with a particularly improved barrier or sealing between the product in the drum and the typically oxygen-rich environment (in the hood chamber). The amount of sealing gas retained in the annular space between the sealing chambers particularly contributes to this further optimized sealing.

[0014] The centrifuge according to the invention is particularly suitable for all centrifugation processes in which the exclusion of oxygen as far as possible is advantageous in order to avoid undesirable oxidation processes.

[0015] This is the case, for example, when processing beverages such as fruit juices and beer: Vitamin C, for example, from citrus fruits and other fruits and vegetables, reacts with oxygen. Other natural products also oxidize, changing their color and taste.

[0016] In a particularly preferred configuration of the invention, the first sealing chamber can be radially separated downwards from the gripper chamber, into which the gripper is inserted, by a lower annular wall, which allows a fluid-tight seal of the drum at a useful location. Furthermore, the walls of the gripper chamber can also be used as walls of the sealing chamber, thus saving installation space.

[0017] In yet another preferred configuration of the invention, the first sealing chamber may be separated from the second sealing chamber by an intermediate wall. This results in a space-saving arrangement of the second sealing chamber radially above the first sealing chamber. Furthermore, in another particularly preferred embodiment of the invention, the centrifuge may have at least one supply channel for supplying sealing liquid to the respective sealing chamber. As a result, if two channels are present, each sealing chamber can be filled separately from the other sealing chamber. This allows one or both sealing chambers to be filled without pressure or with back pressure. This allows the sealing chambers to be filled with sealing liquid flexibly according to the current requirements of the fluid tightness.

[0018] Similarly, in accordance with yet another preferred embodiment of the present invention, the radius R at the mouth of each supply channel in the sealing chamber M1 is the radius R of the outer edge of the intermediate wall AZ This allows a structurally simple and easily realizable pressureless filling of the sealing chamber with the sealing liquid, which depends only on the geometry.

[0019] In yet another preferred embodiment of the present invention, the radius R at the mouth of each supply channel in each sealing chamber is M2 is the radius R of the outer edge of the intermediate wall AZ This results in a structurally simple and easily producible capability, since it depends only on the geometrical shape, to fill the sealing chamber with the sealing liquid under counter pressure.

[0020] In a further particularly preferred configuration of the invention, the sealing gas may flow through a line into the space between the two sealing chambers and exit this space through an outlet for the sealing gas, which results in a structurally simple exchange of the sealing gas.

[0021] Furthermore, in another particularly preferred embodiment of the present invention, a gas sensor, in particular a CO2 sensor, can be provided on the sealing gas line and / or on the outlet. In this way, the requirement for a kind of filling level adjustment of the sealing gas in the space is created in a structurally simple and therefore advantageous manner.

[0022] The present invention also solves the object by a method of operating a centrifuge according to the present invention.

[0023] A feature of this method is that the space between the two sealing chambers is continuously flushed with an inert sealing gas during operation of the centrifuge, thereby flushing out any air or oxygen that may have permeated from the space under the hood through the sealing liquid in the second sealing chamber.

[0024] A continuous exchange of sealing gas from the sealing chamber ensures that the drum is sealed. This greatly reduces unwanted oxygen absorption into the product.

[0025] The centrifuge according to the invention is more robust than a fully sealed centrifuge, since there are no mechanical seals that are subject to wear. The need to seal the gas is much lower than if the entire centrifuge were inerted or the space above the sealing chamber were inerted. Also, the power requirements to drive the centrifuge are reduced, since the entire rotor is no longer rotating in an inert gas that is denser than air. The risk of CO2 escaping and contaminating the space outside the centrifuge is also reduced.

[0026] Another area of ​​application is oxygen-sensitive reactions that can occur in chemical synthesis, for example pharmaceuticals. Typically, the applications involve various reactions under inert gases. Argon in particular can be used here instead of CO2 due to its chemical inertness.

[0027] The invention also provides an advantageous method for operating a centrifuge, in particular a separator, according to the invention.

[0028] This method therefore provides a particularly simple method for operating a centrifuge according to any of claims 1 to 12, i) providing a centrifuge to rotate a drum; ii) providing a suspension to be treated and separating said suspension into at least two phases; iii) filling one of the two sealing chambers with sealing liquid without additional counter pressure via a supply channel leading to said sealing chamber, so that the outlet opening from the supply channel for supplying sealing liquid is not immersed in the sealing liquid in this sealing chamber until the sealing disc in this sealing chamber is immersed in the sealing liquid and the other sealing chamber is continuously filled until it is filled, so that the sealing disc in this sealing chamber is immersed in the sealing liquid and the outlet opening from the supply channel for supplying the sealing liquid is not immersed in the sealing liquid in this sealing chamber until it overflows into the other sealing chamber, so that the sealing disc in this sealing chamber is immersed in the sealing liquid. This method is simple and advantageously results in filling both sealing chambers with sealing liquid.

[0029] Steps ii) and iii) can be carried out sequentially here, and in other variants as well, but can also be carried out simultaneously. Instead of two sealing chambers, in another variant, two or more sealing chambers can be provided, a sealing chamber being located axially directly above another sealing chamber.

[0030] According to claim 14, there is provided a method for operating a centrifuge according to any one of claims 1 to 12, the method comprising the steps of: i) providing a centrifuge to rotate a drum; ii) providing a suspension to be treated and separating said suspension into at least two phases; iii) filling the two sealing chambers with a supply pressure until the two sealing discs are immersed in the sealing liquid.

[0031] Also, this method is simple and advantageously results in filling both sealing chambers with sealing liquid. Steps ii) and iii) can be carried out sequentially here, and in other variants as well, but can also be carried out simultaneously.

[0032] Instead of two sealing chambers, in another variant, two or more sealing chambers can be provided, a sealing chamber being located axially directly above another sealing chamber.

[0033] The further step iv) below comprises iv) pressurizing an annular space during the centrifugal operation of the centrifuge, said annular space being bounded in the axial direction by two sealing discs and an intermediate annular wall being located with a gas, in particular a sealing gas, or The method includes venting gas from the annular space during the centrifuge operation. In this way, the effectiveness of the two axially arranged sealing chambers and the sealing of the gripper chamber against the ingress of ambient air is significantly optimized.

[0034] Finally, the invention also provides the use of a centrifuge according to any of claims 1 to 12 in the processing of beverages and / or the production of chemical compounds, in particular pharmaceutical products.

[0035] Further advantageous configurations are given in the other dependent claims. [Brief description of the drawings]

[0036] Further advantages, features and details of the invention can be seen from the following description, which describes in more detail exemplary embodiments of the invention with reference to the drawings, in which: A person skilled in the art will also usefully consider the features disclosed in the drawings, the description and the dependent claims in combination and, by combining them, form further useful combinations. [Figure 1] FIG. 1 is a schematic diagram of all parts of a centrifuge configured as a separator. [Diagram 2] FIG. 2 shows in detail the head area of ​​a centrifuge drum according to a first configuration with two sealing chambers, the sealing chambers being filled according to a first alternative method. [Diagram 3] FIG. 2 shows in detail the head area of ​​a centrifuge drum according to a first configuration with two sealing chambers, the sealing chambers being filled according to a second alternative method. [Figure 4] 1 shows in detail the head area of ​​a centrifuge drum according to various configurations, the sealing chamber being filled according to alternative methods. [Diagram 5] 1 shows in detail the head area of ​​a centrifuge drum according to various configurations, the sealing chamber being filled according to alternative methods. [Figure 6] 1 shows in detail the head area of ​​a centrifuge drum according to various configurations, the sealing chamber being filled according to alternative methods. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] FIG. 1 shows a centrifuge 1 designed as a separator for separating or purifying a fluid product or a fluid suspension P into at least two phases L, S in a centrifugal field.

[0038] The centrifuge 1 has a rotation system with a drum 2 rotatably arranged on a rotatable spindle 30. The spindle 30 is preferably vertically aligned and can be driven directly or indirectly, for example via a drive belt. The drive is preferably realised by a drive motor of the centrifuge (not shown), in particular an electric motor.

[0039] The drum 2, and in particular the drum shell, can be made from a wide variety of materials. In the context of this specification, the drum 2 or drum shell is made of metal. The drum 2 can have a vertical axis of rotation 3. The drum 2 can be configured for continuous operation. The drum 2 can be essentially single or double conical in configuration.

[0040] The drum 2 first has an inlet. The inlet may have a centrally arranged feed pipe 4, which is stationary during operation of the centrifuge 1 and through which the product P may be fed to the distributor 23 of the drum 2 and from there to the separation chamber 26. The feed pipe 4 forms part of a shaft arrangement 41, which does not rotate during operation and which extends axially from a location outside the drum into the drum 2, but does not rotate with the drum during operation. The shaft arrangement 41 and the drum 2 are therefore arranged radially spaced apart. The inlet may also be arranged differently. For example, the feed pipe 4 may be arranged to rotate and / or be provided at the lower end of the drum 2 (not shown).

[0041] The product P to be treated is fed into the drum 2 through a feed pipe 4, leaves the end of the feed pipe 4 and flows through a distributor 23 which rotates together with the drum 2 before entering the actual separation chamber 26. In this case, it is separated into at least two phases, a liquid phase L and a solid phase S, and in the exemplary embodiment shown in FIG. 1, the solid phase S is separated from the starting product, i.e. the product P to be treated. For this purpose, the product P to be treated enters a stack of separation plates 27 in the separation chamber 26.

[0042] 1 shows diagrammatically on the left a position in which the piston slide 22 closes the discharge nozzle 20, and on the right a position in which the discharge nozzle 20 is open.

[0043] The drum 2 then discharges the solids. The drum may comprise a piston slide 22 and a plurality of discharge openings 20, which are provided as discrete outlets for the solid phase S. The drum 2 comprises at least one gripper chamber 5 which rotates together with the drum 2 during operation of the centrifuge 1, and into which a gripper 8 (also called a pulping disc in technical terms) is inserted while the centrifuge 1 is operating.

[0044] The gripper 8 works according to the principle of a centripetal pump. Thus, one liquid phase L is discharged from the drum 2 through one or more discharge channels 81 in the gripper 8 via a discharge pipe 82. It is also possible to provide two grippers 8 and a gripper chamber 5 arranged axially above one of them in order to discharge the two liquid phases. The drum 2 is then preferably configured to separate into two liquid phases and one solid phase (not shown).

[0045] Above the gripper chamber 5 there is provided a first sealing chamber 7 which runs around the periphery of the drum 2. The first sealing chamber 7 serves to form a first fluid-tight seal.

[0046] In the first sealing chamber 7, which rotates together with the drum 2 during operation of the centrifuge 1, a first sealing disk 9 is arranged for this purpose, which can be rigidly connected to the shaft arrangement 41 directly or via a further element and therefore does not rotate during operation of the centrifuge 1. The sealing disk 9 extends radially outwards into the sealing chamber 7, perpendicular to the axis of rotation 3.

[0047] The first sealing chamber 7 is formed perpendicular to the axis of rotation 3. The drumhead 29 may be completely cylindrical or the outer drum wall or shell may have an upper portion that is essentially cylindrical.

[0048] The second sealing chamber 12 is arranged axially above the first sealing chamber 7. A second sealing disk 14 is inserted into the second sealing chamber 12, which is also rigidly connected to the shaft arrangement 41 so that it does not rotate during operation of the centrifuge 1. The sealing disks 14 also extend radially from the inside to the outside. They are formed perpendicular to the axis of rotation 3.

[0049] The two sealing chambers 7, 12 are each bounded axially by an annular wall 16, 17, 18, which extends radially inwardly perpendicular to the axis of rotation 3 starting from the inner circumference of the drum shell of the drumhead 29. The annular walls 16, 17, 18 are radially spaced apart from an inner non-rotating shaft arrangement 41 or shaft assembly, which comprises a feed pipe 4 and at least one axial gripper channel 81 from the gripper 8 of the pulping disc or drum 2. The sealing chambers 7, 12 are each bounded radially outwardly by the drum shell.

[0050] The sealing chambers 7, 12 can be pressurized with a liquid sealing medium 32 - in particular water, or the product P to be processed itself - and then a liquid ring / cylinder is formed radially on the outside of the respective sealing chamber 7, 12. This is dimensioned so that the sealing discs 9, 14 are made to radially penetrate the sealing medium 32 during operation of the centrifuge 1, forming a double watertight seal.

[0051] For this purpose, at least one supply channel 11 is provided, or alternatively several supply channels 11, 11' may be provided. Each supply channel 11, 11' preferably extends from a position outside the drum 2 through a shaft arrangement 41 into the respective sealing chamber 7 and / or 12. The sealing medium 32 can flow into the supply channel 11, 11', for example from a reservoir 31 located outside the centrifuge.

[0052] For example, only one supply channel 11 can extend into the lower sealing chamber 7 (FIG. 2 or FIG. 3). However, it is also possible for one supply channel 11, 11' to extend in each case into each of the sealing chambers 7, 12 (FIG. 4, FIG. 5 or FIG. 6).

[0053] During operation, liquid sealing medium 32 is supplied to the sealing chambers 7, 12 through the respective supply channels 11, 11', and this liquid sealing medium 32 collects in the two sealing chambers 7 and 12 as a result of the centrifugal forces arising during rotation of the outer drum and forms a liquid ring therein.

[0054] When the sealing discs 9, 14 are radially immersed from the inside into the respective liquid rings in the respective sealing chambers 7, 12, a fluid seal is formed between the gripper chamber 5 and the interior of the hood or the surrounding space of the drum 2 within the hood 21 by interaction of the sealing discs 9, 14 with the liquid rings in the respective sealing chambers 7, 12.

[0055] This is particularly advantageously achieved through various configuration variations and / or processing technique alternatives. For example, water or the product to be treated can be used as the sealing medium 32. Other sealing media are also contemplated.

[0056] The first sealing chamber 7 is bounded radially downwards from the gripper chamber 5 by a lower annular wall 16, into which the gripper 8 is inserted. The first sealing chamber 7 is further separated from the second sealing chamber 12 by an intermediate annular wall 17. The second sealing chamber 12 has a radially annular wall 18 at the top, which bounds it above and has a radially inner spillover edge 15, at which liquid can escape from the rotating system into the hood chamber 21.

[0057] FIG. 2 shows a detailed representation of the drumhead 29 of the drum 2 of the centrifuge 1 according to a first design configuration, in which the supply of sealing liquid is provided according to a first alternative.

[0058] According to this configuration, a feed channel 11 extends from the outer region of the drum 2 through an axially extending non-rotating inner shaft arrangement 41 into the region of the lower sealing chamber 7. The feed channel 11 here terminates axially above the lower sealing disc 9 in the lower first sealing chamber 7, where it has a radially aligned outlet, which is located further radially inwards than the outer edge of the first sealing disc 9.

[0059] On the other hand, the upper second sealing chamber 12 does not have its own supply channel, and if present, it is not used. In this configuration, according to the first process engineering alternative, the upper sealing chamber 12 is therefore filled with sealing medium 32 via the lower sealing chamber 7, i.e. via a supply channel opening into the lower sealing chamber 7.

[0060] A control unit is provided for controlling the operation of the separator, which may also be used to control or regulate the filling of the sealing chambers 7, 12 during operation. This is done as follows:

[0061] First, a centrifuge 1 as shown in Fig. 1 is provided, in particular a centrifuge 1 having a drum head 29 as shown in Fig. 2. Then, the drum 2 is set in a rotating state by a drive unit (not shown here).

[0062] The lower first sealing chamber 7 is then filled with sealing liquid via the supply channel 11 . The outlet opening from the supply channel 11 for supplying the sealing liquid is not immersed in the sealing liquid in the first sealing chamber 7 - in this case, due to the arrangement selected in FIG. 2, no counterpressure is added.

[0063] This is the radius R at the mouth of the supply channel 11 in the sealing chamber 7. M1 is the radius R of the radially inner edge of the intermediate annular wall 17.AZ This can happen because it is smaller than

[0064] After the first sealing chamber 7 has overflowed, the upper second sealing chamber 12 is filled, since the lower annular wall 16 between the first sealing chamber 7 and the gripper chamber 5 extends further radially inward than the intermediate annular wall 17 between the two sealing chambers 7, 12. When the upper second sealing chamber 12 overflows, the sealing liquid passes through the overflow edge 15 into the hood space inside the hood 21 .

[0065] Alternatively, the upper sealing chamber 12 can also be filled, which overflows into the lower sealing chamber 7. The feed channel 11' then flows into the upper sealing chamber 12. Any sealing chamber 7, 12 may each be provided with a supply channel 11. In this case, one supply channel is not used for filling, according to either of the two methods described above.

[0066] FIG. 3 shows in detail the drumhead 29 of the drum 2 of the centrifuge 1 according to the first configuration of FIG. 2, in which the supply of sealing liquid takes place according to a second process engineering alternative.

[0067] First, a centrifuge is provided that includes a drum 2 as shown in Fig. 1 and a drum head 29 as shown in Fig. 3. Then, the drum 2 is set in a rotating state by a drive unit (not shown here). The first sealing chamber 7 is in turn filled with sealing liquid through the supply channel 11. The supply channel 11 for supplying the sealing liquid is immersed in the sealing liquid in the first sealing chamber 7 and is supplied with the required supply pressure.

[0068] This is the radius R at the mouth of the supply channel 11 in the sealing chamber 7. M2 is the inner radius R of the intermediate wall 17. AZ This can happen because it is larger than The filling level of the sealing liquid can be adjusted via the inlet pressure. This is preferably done automatically by a control unit (not shown here).

[0069] After the first sealing chamber 7 overflows, the second sealing chamber 12 becomes full. When the second sealing chamber 12 overflows, the sealing liquid enters the hood space. In this way, an excellent seal between the hood space and the gripper chamber 5 is achieved by a multiple sealing chamber arrangement - in this case a double sealing chamber arrangement having two axially adjacent sealing chambers 7 and 12.

[0070] It is still possible that some oxygen may diffuse into the sealing liquid, resulting in very low oxygen uptake of the product P and / or the discharged liquid phase L. In centrifuges with a sealed liquid phase outlet, atmospheric oxygen can be replaced with an inert gas such as CO2.

[0071] FIG. 4 shows a detailed view of the drumhead 29 of the drum 2 of the centrifuge 1 according to a second configuration, in which the supply of sealing liquid is provided according to a first alternative. Apart from the drumhead 29, the drum 2 can be constructed, for example, as shown in FIG.

[0072] Two axially superimposed sealing chambers 7, 12 are also provided. The configuration of the sealing chamber and its annular walls 16, 17, 18 may be configured as shown in FIG. 2 or FIG. The introduction of the sealing liquid into each sealing chamber 7, 12 is solved in different ways.

[0073] The two sealing chambers 7, 12 are filled completely separately with sealing liquid, as shown in Fig. 4. For this purpose, a separate supply channel 11, 11' opens into each of the two sealing chambers 7, 12. Each sealing chamber 7, 12 allows sealing liquid to be supplied separately from the area outside the drum 2 through the respective supply channel 11, 11' into the respective sealing chamber 7, 12.

[0074] In this way, various filling processes can be realized. First, a first alternative example shown in FIG. 4 will be described, followed by a second alternative example shown in FIG. First, the centrifuge shown in Figure 1 with the drum head 29 shown in Figure 2 is provided in the manner shown in Figure 4. Next, the drum 2 is set to rotate by a drive (not shown here).

[0075] The sealing liquid is then supplied to the two sealing chambers 7, 12 via the supply channels 11, 11', so that the channels 11, 11' are not radially and totally immersed in the sealing liquid in the respective sealing chambers 7, 12. According to this alternative, the sealing liquid is added without back pressure.

[0076] This is due to the radius R at the mouth of each supply channel 11, 11' in each sealing chamber 7, 12. M1 is the radius R of the outer edge of the intermediate wall 17 AZ This can happen because it is smaller than The outlet of the supply channel 11 ′ into the upper sealing chamber 12 is preferably arranged above the (axially upper) sealing disk 14 in this upper sealing chamber 12 . The outlet of the supply channel 11 into the lower sealing chamber 7 is preferably located above the (axially lower) sealing disk 9 in the lower sealing chamber 12 .

[0077] The amount of sealing liquid is preferably dispensed by a control device such that the sealing liquid does not overflow into the hood space. By suitable control and loading, a further annular space 19 can be formed around the intermediate annular wall 17 between the two sealing discs 9,14.

[0078] A further line 24 opens into this annular space so that a fluid, such as a gas, can be supplied into the annular space 19 from a location external to the rotating system. This line 24 may also run through or together with the non-rotating shaft arrangement 41. By suitable control and loading, a further annular space 19 can be formed around the intermediate annular wall 17 between the two sealing discs 9, 14. This annular space 19 forms a U-shaped cross section around the free end of the intermediate annular wall 17.

[0079] The annular space 19 is continuously flushed with inert sealing gas 13 during operation of the centrifuge 1, so that any air or oxygen that may have permeated from the space below the hood 21 through the sealing liquid in the second sealing chamber 12 is flushed out. The escape of the sealing gas 13 leaving the annular space 19 takes place outside the hood 21. The sealing gas 13 is retained in the annular space 19 by the two sealing discs 9, 14. The pressure in the annular space 19 can be set relatively freely by a control device, both overpressure and underpressure being possible.

[0080] The annular space 19 can also be filled only with the sealing gas 13. In this case, the two sealing chambers 7, 12 are not filled with a sealing liquid. The inert sealing gas 13 is preferably CO2. The sealing gas 13 can be fed into the annular space 19 from a gas reservoir (not shown here) via a line 24. Additionally, an outlet 25 for the sealing gas 13 from the annular space 19 can be provided.

[0081] Since CO2 is heavier than air or oxygen, it is pushed outside the rotating annular space 19 during operation of the centrifuge 1. As a result, any air or oxygen that has entered the annular space 19 is expelled from the annular space 19. This creates an effective barrier against further ingress of air, and therefore oxygen, into the drum 2.

[0082] The sealing gas 13 is supplied to the annular space 19 by actuators (not shown here), e.g. valves, which are controlled by a control unit to regulate the gas supply to the annular space 19 .

[0083] FIG. 5 is a detailed view of the drumhead 29 of the drum 2 of the centrifuge 1 according to the second configuration, in which the supply of sealing liquid is also provided according to the first alternative. The two sealing chambers 7, 12 are filled with sealing liquid separately. The channels 11, 11' are not permeated with the sealing liquid in the respective sealing chambers 7, 12 and the sealing liquid is added without back pressure.

[0084] This is due to the radius R at the opening of the channels 11, 11' into the respective sealing chambers 7, 12. M1 is the radius R of the outer edge of the intermediate wall 17 AZ This can happen because it is smaller than The amount of sealing liquid is injected by a control device such that the sealing liquid does not overflow into the space under the hood 21 .

[0085] The annular space 19 between the two sealing discs 9, 14 is continuously flushed with an inert sealing gas 13 during operation of the centrifuge 1, thereby making it possible to flush out any air or oxygen which may have entered from the space below the hood 21 through the sealing liquid in the second sealing chamber 12. The escape of the sealing gas 13 leaving the annular space 19 takes place inside the hood 21. The sealing gas 13 is contained in the annular space 19 by two sealing discs 9, 14. The pressure in the annular space 19 can be set relatively freely by a control device, both overpressure and underpressure are possible.

[0086] FIG. 6 shows a detailed view of the drumhead 29 of the drum 2 of the centrifuge 1 according to a second configuration, in which the supply of sealing liquid takes place according to a second alternative. The two sealing chambers 7, 12 are filled separately with sealing liquid. The channels 11, 11' are permeated with sealing liquid in the respective sealing chambers 7, 12, and sealing liquid is added with counter pressure.

[0087] This is the radius R at the opening of the channels 11, 11' into the sealing chambers 7, 12. M2 is the radius R of the outer edge of the intermediate wall 17 AZ This can happen because it is larger than The volume of sealing liquid is dispensed by a control device such that the sealing liquid does not overflow into the space below the hood 21 .

[0088] The annular space 19 between the two sealing discs 9, 14 is continuously flushed with inert sealing gas 13 during operation of the centrifuge 1, so that any air or oxygen that may have permeated through the sealing liquid in the second sealing chamber 12 from the space below the hood 21 can be flushed out. The escape of the sealing gas 13 leaving the annular space 19 can be done inside or outside the hood 21. The sealing gas 13 is held in place by the two sealing discs 9, 14. The pressure in the annular space 19 can be set relatively freely by the control device, both overpressure and underpressure are possible.

[0089] There is little or no mixing of the product flow with the sealing gas 13 in the gripper chamber 5 below the first sealing chamber 7. If so, this does not adversely affect the product, since CO2 is also commonly used in the beverage industry. As an alternative to CO2, other gases that are heavier than air can also be utilized to displace air and thus atmospheric oxygen. Ideally, this should also be an inert gas such as argon.

[0090] Since gas, unlike liquids, is compressible, it can be assumed that the amount of gas in the annular space 19 decreases as the rotational speed or velocity of the drum 2 increases. Thus, the supply 24 of sealing gas 13 during operation of the drum 2 can be detected as a function of the rotational speed or velocity, or alternatively.

[0091] Gas sensors, in particular CO2 sensors, can also be provided on the line 24 and / or on the outlet 25 of the sealing gas 13, so that a kind of "level control" can be performed by the control unit controlling the actuator. It is also possible to go back to empirical values, available for example in the form of a data record in the data memory of the control unit. If the rotation speed is increased, more sealing gas 13 can be fed accordingly. It is also possible to only provide a prototype of the centrifuge 1 of the invention with a sensor in order to determine the required feed amount at the appropriate rotation speed. This can then be stored in the data memory of the series of products as a data record for the appropriate dimensioning of the feed amount of sealing gas 13 as a function of speed.

[0092] Unwanted oxygen absorption into the product is significantly reduced by the present invention. The centrifuge 1 of the present invention is more robust than centrifuges of a completely sealed design due to the absence of mechanical seals that are prone to wear. The need to seal the gas 13 is significantly lower than inerting the entire centrifuge or inerting the space above the sealing chambers 7, 12. Also, the power required to drive the centrifuge 1 is reduced, since the entire rotor no longer rotates in inert gas. The risk of CO2 escaping and contaminating the space outside the centrifuge 1 is also reduced.

[0093] The separator or centrifuge 1 according to the invention is suitable for all process operations in which the exclusion of oxygen is advantageous in order to avoid undesirable oxidation processes.

[0094] This is the case, for example, when processing beverages such as fruit juices or beer. For example, vitamin C from citrus fruits and other fruits and vegetables reacts with oxygen. Other natural products also change their color and taste when oxidized. Other applications are oxygen-sensitive reactions that can occur in chemical synthesis, for example pharmaceuticals. Typically, applications include various reactions under inert gases. Argon in particular can be used here instead of CO2 due to its chemical inertness. [Explanation of symbols]

[0095] List of symbols 1. Centrifuge 2 Drums 3 Rotation Axis 4 Supply Pipe 41 Shaft device 5 Gripper Room 7 First Sealing Room 8 Gripper 81 Discharge Channel 82 Exhaust pipe 9 First sealing disc 11, 11' supply channel 12 Second Sealing Room 13 Sealing gas 14 Second sealing disc 15 Overflowing Edge 16 Lower annular wall 17 Middle annular wall 18 Upper annular wall 19 Annular Space 20 Discharge nozzle 21 Food 22 Piston slide 23 Distributor space 24 Line 25 Exit 26 Separation space 27 Separation Plate Layer 29 Drum Head 30 Spindle 31 Storage 32 Sealing media P suspension L Liquid phase S Solid phase R M1 radius R M2 radius R AZ radius

Claims

1. A centrifuge (1) for separating or washing a fluid product or a fluid suspension into at least two phases in a continuous operation, comprising: The drum (2) is driven by a drive motor and has a rotatably mounted drum (2) with a rotation axis (3) perpendicular to the drum shell made of metal; The drum (2) comprises at least one gripper chamber (5) with a feed pipe (4) and a gripper (8) for discharging the washed or separated liquid, preferably solid waste, the drum (2) comprises at least two axially superimposed sealing chambers (7, 12) above the gripper chamber (5), each sealing chamber (7, 12) having a sealing disk (9, 14) projecting into the respective sealing chamber (7, 12), A centrifuge (1), characterized in that at least one supply channel (11, 11') is provided for supplying the sealing medium (32) to one of the sealing chambers (7, 12) or at least one supply channel (11, 11') is provided for supplying the sealing medium (32) to each sealing chamber (7, 12).

2. 2. The centrifuge (1) according to claim 1, further comprising a line (24) for supplying gas into or discharging gas from an annular space (19) around an annular intermediate wall (17) extending radially inwardly from the drum shell between the two sealing chambers (7, 12).

3. 3. A centrifuge (1) according to claim 1 or 2, characterized in that an outlet (25) is provided for discharging gas from the annular space (19).

4. 3. A centrifuge (1) according to claim 2, characterized in that during operation of the centrifuge (1), a sealing gas (13) which is heavier than air is introduced into the annular space (19) between the two sealing discs (7, 12).

5. 3. A centrifuge (1) according to claim 1 or 2, wherein the lower first sealing chamber (7) is delimited radially downwards from the gripper chamber (5) by an annular wall (16) which extends radially inwardly from said drum shell in the region of the drum head (29), perpendicular to the rotation axis (3) and terminates radially spaced apart from an inner shaft arrangement (41) which does not rotate with the drum (2) during operation but extends axially into the drum (2).

6. 3. A centrifuge (1) according to claim 1 or 2, wherein the first sealing chamber (7) is axially separated from the second sealing chamber (12) by an annular intermediate wall (17) and extends radially inwardly from said drum shell, in the region of the drum head (29), perpendicular to the axis of rotation (3) and terminates radially spaced from an inner shaft arrangement (41) which does not rotate with the drum (2) during operation, but which extends axially into the drum (2).

7. 3. The centrifuge (1) according to claim 1 or 2, wherein the second sealing chamber (12) has an upper radial annular wall (18) which bounds the upper side and extends radially, perpendicular to the axis of rotation (3) and inwardly from the drum shell in the region of the drum head (29) and terminates radially spaced from an internal shaft arrangement (41) which does not rotate with the drum (2) during operation but extends axially into the drum (2), the annular wall (18) having a radially inner overflow edge (15).

8. 3. A centrifuge (1) according to claim 1 or 2, wherein the radius RM1 at the mouth side of each supply channel (11, 11') in the sealing chamber (7) is smaller than the radius RAZ of the radially inner edge of the intermediate wall (17).

9. 3. A centrifuge (1) according to claim 1 or 2, wherein the radius RM2 at the mouth side of each feed channel (11, 11') in the respective sealing chamber (7, 12) is greater than the radius RAZ of the inner edge of the intermediate wall (17).

10. 3. The centrifuge (1) according to claim 1 or 2, characterized in that the line (24) and / or the outlet (25) for the sealing gas (13) is provided with a gas sensor.

11. 3. The centrifuge (1) according to claim 1 or 2, wherein the sealing medium (32) flows into the supply channel (11, 11') from a reservoir (31) located outside the centrifuge (1).

12. 3. The centrifuge (1) according to claim 1 or 2, wherein the sealing gas (13) flows into the annular space (19) from a gas reservoir via a line (24).

13. A method for operating a centrifuge (1) according to claim 1 or 2, comprising the steps of: i) providing a centrifuge to rotate the drum (2); ii) providing a suspension to be treated (P) and separating said suspension into at least two phases (L, P), iii) filling one of the two sealing chambers (7) with sealing liquid without additional counter pressure via a supply channel (11) leading to said sealing chamber (7), so that the sealing disc (9) in this sealing chamber is immersed in the sealing liquid and the outlet opening from the supply channel (11) for supplying the sealing liquid is not immersed in the sealing liquid in this sealing chamber (7) until it overflows into the other sealing chamber (12), with successive fillings until the other sealing chamber (12) is filled, such that its sealing disc (14) is immersed in the sealing liquid.

14. A method for operating a centrifuge (1) according to claim 1 or 2, comprising the steps of: i) providing a centrifuge to rotate the drum (2); ii) providing a suspension (P) to be treated and separating said suspension (P) into at least two phases (L, P), iii) filling the two sealing chambers with a supply pressure until the two sealing discs (9, 14) are immersed in the sealing liquid.

15. The centrifuge (1) has the configuration described in claim 2, and further comprises: iv) pressurizing the annular space (19) during the centrifugal operation of the centrifuge, the annular space (19) being axially bounded by two sealing discs (9, 14) and the intermediate annular wall (7) being located with a gas, in particular a sealing gas (13), or evacuating the annular space (19) during the centrifugal operation of the centrifuge.

16. 16. The method according to claim 15, wherein an inert gas is used as the sealing gas (13).

17. 16. The method according to claim 15, wherein a sealing gas is supplied to the annular space (19) through a line (24) and discharged from the annular space (19) through a discharge line (25).

18. 16. The method according to claim 15, wherein the supply of sealing gas (13) into the annular space (19) is performed as a function of the rotation speed of the drum (2) during operation of the centrifuge (1).

19. 16. The method according to claim 15, characterized in that the supply of sealing gas (13) into the annular space (19) and the discharge of sealing gas (13) from the annular space (19) are performed during operation of the centrifuge (1) depending on the filling level of the annular space (19).

20. Use of the centrifuge (1) according to claim 1 or 2 in beverage processing and / or chemical synthesis of compounds, in particular pharmaceuticals.

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