DE2263059A1 - PROCESS FOR CONCENTRATING LIQUIDS AND DEVICE FOR CARRYING OUT THE PROCESS - Google Patents

Description

Patent attorneys Dipl.-Ing. F. Weickmann,

Dipl.-Ing. H. Weickmann ,. Dipl.-Phys. Dr. K. Fincke Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Huber

8 MÜNCHEN 86, POST BOX 860 820 hk MÖHLSTRASSE 22, CALL NUMBER 98 3921/22

71FG5 / 6

Struthers Scientific and International Corporation 630 Fifth Avenue, New York, N.Y. 10020, V.St.A.

"Method for concentrating liquids and apparatus for carrying out the method"

The invention relates to the concentration of liquid coffee extract, Tea, beer and citrus fruit juices.

It is known liquid coffee extract of the freezer concentration to subdue, obtaining a slurry of ice and liquid. The slurry is in a centrifuge fed, in which the concentrated liquid is separated from the ice. A particular difficulty is posed by the Foam formation in the "'.Centrifuge". To remove the foam An interruption in the operation of the plant may even be required

be. The foam usually contains valuable coffee solids.

In accordance with the present invention, the foam becomes in liquid transferred and combined with the charge. ^ liquid, the aur Freeze concentrator is returned.

The foam from the centrifuge can be removed with the wash water used to wash the ice and fed to a secondary feed liquid storage tank. This container contains liquid that is fed into a crystallizer or other freezer. From here the liquid is fed back into the centrifuge, and the foam from the storage tank is fed into a treatment tank in which the foam is either stored for long periods, e.g. 2 to 24 hours and usually 8 to 16 hours, or by treatment with steam is converted into liquid. The liquid is then returned to a primary storage tank containing fresh feed liquid, such as from coffee extractors, from which the mixture is fed to the secondary storage tank. This storage container can be arranged in front of or behind a filter or solid bowl centrifuge to remove wax or other deposits.

It was to be assumed that the foam either by long Standing or liquid formed by treating with steam would have an undesirable aroma. Surprisingly, however, it was found found that when this liquid is mixed with the feed liquid, the treatment in the freezer concentrator and then converting the mixture

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in a powder or granulate a high quality, soluble one Coffee of excellent taste is obtained.

The foam can also be used with the freeze-concentrating centrifuge Leave mother liquor. This mixture can then be fed into a storage container, from which the foam is produced in the same way treated and ir. liquid can be transferred. This liquid is returned and mixed with freshly supplied, liquid coffee extract.

The ice from the centrifuge can be fed into a melting container with foam. The temperature of the container contents is increased so that the foam is converted into liquid, this conversion occurring so rapidly that no accumulation of foam occurs. For this purpose, the temperature of the container contents to 26.7 to 65.6 may G ^0, preferably to 52.2 to 43.3 ° C can be increased. The temperature rise can be caused by steam coils, electrically heated heating coils, or in any other suitable manner.

Part of the foam or all of the foam with the mother liquor can also be mixed with the mother liquor, with a Foam mass is obtained, which is frozen and freeze-dried.

The examples illustrate the invention. Reference is made to FIGS. 1 to 3 in the examples.

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- Item ₁ . -

2283059

example 1

In Fig. 1 the invention is shown in application to a single-stage concentration system. IO and 11 are two primary storage tanks. Feed liquid originating from coffee extractors is fed into the storage container IO at 12. The liquid from the reservoir 10 may be 1.67 to ⁰ C, are at a low temperature, for example from -1.67, thereby promoting the precipitation of waxes and the like to which deposited material. The precipitate is removed by means of a filter or solid jacket centrifuge 13 before it is fed into the storage container 11. The liquid from the storage container 11 is fed into a secondary storage container 17 by means of a pump 16. The liquid from the storage container 17 is fed into a crystallizer 20 by means of a pump 18. The crystallizer 20 represents the first part and the centrifuge 21 represents the second part of a freeze concentrating device. In the crystallizer 20, ice is created in the liquid. The resulting slurry of ice and liquid is fed into the centrifuge 21. The centrifuge 21 can be a known centrifuge with a rotating screen basket from which the ice is continuously scraped off. The ice is fed into a melting vessel 23 through line 22. Part of the liquid from the container 23 is discharged as waste water through a line 24; another part of the liquid is pumped into the centrifuge 21 by means of a pump 27 through a line 28 and serves as wash water for washing the ice, coffee solids being removed from the ice. The wash water is together with "foam from the centrifuge 21 through a line

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device 30 is fed into a secondary reservoir 17. the Mother liquor, which passes through the strainer basket, is fed into a mother liquor container 32 via a line 31.

The through suitable drainage channels or channels 34 and 35 from the Storage container 17 and the mother liquor container 32 overflowing Foam is fed into a container 36 in which the foam held for a few hours and / or treated with steam, as a result of which it is converted into liquid. This liquid is then fed into one or both reservoirs 10 and 1Ϊ by means of a pump 40.

A part of the liquid can by means of a pump 41 from the outlet of the crystallizer 20 can be returned to its inlet.

Example 2

In Fig. 2 the invention is shown applied to a two-stage concentration system. The two tier system is similar to the system shown in Figure 1; the liquid however, from the container 32 into a second crystallizer 50 pumped. The slurry obtained from this crystallizer is fed into a second centrifuge 51. The ice out the centrifuge 5I is fed into a container 17 via a line 52 fed in. The mother liquor from the centrifuge 51 is via a Line 54 is fed into a product container 55. That. Ice out of the Centrifuge 21 is fed into a melting vessel 56 via a line 22. The wash water from the centrifuge 21 is fed via a line 30 into a 'washing water tank 57. By overflowing foam, which consists of one or of velvet

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common containers 32, 57 »17 and 55 is placed in the container 36 fed in, from where the resulting from the foam Liquid is pumped back into one or both reservoirs 10 and 11.

Example 3

3 shows a centrifuge 60 into which a slurry of ice and coffee liquid originating from a crystallizer is fed at 61. The centrifuge 60 may have a rotating screen basket from which the ice is scraped and fed into an outlet conduit or chute 62. The mother liquor exits the centrifuge 60 at 63 and the wash water exits at 64. The ice is fed together with the foam into a container 66 which is heated with a heater 67 to about 37.8 ^0C. The foam is converted into liquid and partly discharged as waste water at 69 (or returned to the coffee extractors), partly through a pump 70 and a line 71 at 72 into the centrifuge as ash water for the centrifuge basket and partly at 73 to the V / ashes of the ice in the centrifuge are fed into this. The washing water can be cooled if necessary.

The application of the present invention also includes that in US Pat

British Patent Applications Nos. 1,196,601, 1,196,602, 1,199,914,

1,178,775, 1,178,774, 1,178,772, 1,172,836, 1,172,838, 1,172,832 and 1,172,835 proposals and inventions disclosed.

Ι 09830/0394

Claims (1)

Claims 1. Method of concentrating liquids, such as coffee extract, Tea, beer or citrus fruit juices by freeze concentration of the liquid, feeding the obtained slurry of ice and concentrated liquid into a Centrifuge and separating the concentrated liquid from the ice, characterized in that one separates the foam formed in the centrifuge from the ice and from the concentrated liquid and treats it further, that it is contained in the concentrated end product. 2. A method for concentrating liquids, such as coffee extract _f tea, beer or citrus fruit juices, by freeze-concentrating the liquid, feeding the resulting slurry of ice and concentrated liquid into a centrifuge and separating the concentrated liquid from the ice, characterized in that the foam formed in the centrifuge is converted into a liquid and this liquid is mixed with the feed liquid to be freeze-concentrated. 3. The method according to claim 1, characterized in that the feed liquid from a primary storage container in a secondary reservoir, from the secondary reservoir into a freeze concentrator and then into transferred to a centrifuge, the ice in the centrifuge with Wash water washes, the wash water and foam feeds into the secondary storage tank, the foam from the storage tank feeds into a Schaura treatment tank, the 109830/8394 Foam is liquidated in this foam treatment tank and this liquid is transferred to the primary storage tank feeds. 4. The method according to claim 1 or 2, characterized in that the mother liquor with some foam from the centrifuge is fed into a mother liquor container, the foam from the mother liquor container removed and converted into a liquid and the liquid into the liquid to be freeze-concentrated feeds. 5. The method according to claim 1, 2 or 3>, characterized in that that one from a first freeze concentration and centrifugation The resulting liquid is subjected to a second freeze-concentration and centrifugation, the foam from the The second centrifugation stage is transferred into liquid and this liquid is fed into the liquid to be fed into the first concentration stage Feeds liquid. 6. The method according to claim 1, characterized in that the foam is mixed with mother liquor and the foam mass thus obtained freezes and freeze-dried. 7. The method according to claim 1 to 6, characterized in that the foam is exposed to a temperature in a container, which is high enough to convert the foam into a liquid. 8. The method according to claim 7 »characterized in that the Exposing foam to a temperature of 26.7 to 65.6 ° C. 309830/0394 9 · A method according to claim 7 * characterized in that exposing the foam to a temperature of 32.2 C 4 to 3.3 ^0. 10. Apparatus for performing the method according to claim 9, characterized by a crystallizer, devices for feeding liquid into the crystallizer, a centrifuge, means for feeding a slurry of liquid and ice from the crystallizer to the centrifuge, a foam treatment tank, facilities for feeding the foam from the centrifuge into the foam treatment tank and means for transferring it the liquid from the foam treatment container into the coffee liquid. 11. Embodiment according to claim 10, characterized by a storage container for receiving the foam from the centrifuge and means for transferring the foam overflowing from the storage container into the foam treatment container. 12. Embodiment according to claim 10 or 11, characterized through two storage containers, one of which is a mother liquor container connected to the mother liquor outlet of the centrifuge and the other is a container connected to the ice wash water and foam outlet of the centrifuge, and Facilities for transferring the overflowing from both containers Foam into the liquid to be fed into the crystallizer. ·, 13 ·. * Usx aimingsf arm according to claims 10 to 12, characterized through two primary storage containers for those in the crystal! - 309830/0394 sator liquid to be fed, means for connecting one primary reservoir to the other through one filter or centrifuge and one between the foam treatment tank and a pump arranged to one or both of the primary reservoirs. 14. Embodiment according to claim 10, characterized by a second crystallizer, whose Auelaß with a second centrifuge is connected, a first storage container (17), means for supplying liquid to be treated in the storage container, devices for feeding ice from the second centrifuge into the storage container, devices for feeding liquid from the storage container into the first crystallizer, a second storage container (32 or 57) »Equipment for feeding liquid and foam from the first centrifuge into the second storage container and Means for transferring the foam overflowing from the first and second storage containers into the foam treatment container. 15. Method according to claim 14, characterized by a third Storage container, the second and third storage container with the first centrifuge for receiving mother liquor or is connected by ice wash water from the centrifuge, and the foam transfer devices are arranged so that they transfer the foam overflowing from the second and third storage tanks into the foam treatment tank. . Embodiment according to claim 14 or 15, characterized 309830/0394 by two primary storage tanks for those in the first Crystallizer liquid to be fed, facilities for connecting the two primary storage tanks via one Sediment separator, with the foam treatment tank connected to one or both of the primary storage tanks and the primary storage tank, into which liquid flows from the sediment separator, with the first storage tank connected is. • 17 · Device according to claim 10 to 16, characterized by a foam treatment tank containing a heater in its lower part. 18. Embodiment according to claim 10, characterized by a Foam treatment container, which is connected to the centrifuge for receiving ice and foam from the centrifuge and also for Supply of liquid as washing water for the centrifuge basket and or, or as ice washing water separately 'with the Centrifuge is connected. 309830/0394 Blank page