DEVICE AND PROCESS FOR THE PRODUCTION OFFINE FAT PARTICLES

Abstract

A device and to a process which can be carried out using the device, for the production of fine particles from a liquid which solidifies upon cooling, in particular from liquid fat. The process has the advantage of producing fine particles of very small size, preferably with narrow size distribution. The device has the advantage that a solidifying liquid can be supplied at a temperature above its solidification temperature, without cooling gas leading to solidification of the liquid in the supply line, which cooling gas is used in the production of the particles.

Claims

1. Process for producing particles from liquid fat having a temperature above its solidification temperature, by cooling, wherein the liquid fat is conducted through a supply line into the area of a nozzle, in which area negative pressure is generated, while propellant gas is directed to the inlet opening of the nozzle, flowing through of the central channel of the nozzle, which central channel tapers to a section of smallest radius, and discharging the mixture of the propellant gas with the fat from an outlet opening of the nozzle which lies opposite to the inlet opening, wherein the propellant gas has a temperature of at least 50 K below the solidification temperature of the liquid fat, with subsequent cooling of the mixture of the propellant gas with the fat and removing particles from the propellant gas.

2. Process according to claim 1, wherein, subsequent to the central channel which tapers to a section of smallest radius, a second section of the central channel is flowed through, in which second section the central channel widens to the outlet opening.

3. Process according to claim 1, wherein the central channel, which is spanned open by the face that is convex to the longitudinal axis, tapers from the inlet opening to a section in which the central channel has its smallest radius and is spanned open by a convex face which extends radially about the longitudinal axis of the central channel and which extends rotationally symmetrically about the longitudinal axis of the central channel

4. Process according to claim 1, wherein the propellant gas supply line forms an annular supply line having an annular opening at the inlet opening of the central channel, and the annular opening of the supply line is limited by the surface of the central channel, which surface spans open the inlet opening of the central channel.

5. Process according to claim 1, wherein the cooling of the mixture of the propellant gas with the liquid occurs by the mixture of the propellant gas with the liquid exiting from the nozzle entering a space which is filled with gas having a temperature of at least 50 K below the solidification temperature of the liquid.

6. Process according to claim 1, wherein subsequent to the mixture of the propellant gas with the fat exiting from the outlet opening of the nozzle, this mixture is cooled by gas guided in counterflow which is supplied from a counterflow unit, wherein the gas has a temperature of at least 50 K below the solidification temperature of the liquid.

7. Process according to claim 1, wherein gas which has exited from the nozzle as propellant gas and which was separated from particles is compressed, cooled, and recirculated.

8. Process according to claim 1, wherein through a counterflow unit, a flow of gas having a temperature of at least 50 K below the solidification temperature of the liquid fat is directed against the gas flow exiting from the outlet opening.

9. Process according to claim 6, characterized in that the gas exiting from the counterflow unit is gas which has exited the nozzle, was separated from particles, was compressed and cooled, and is recirculated.

10. Process according to claim 1, wherein the propellant gas and/or the gas which is supplied to the counterflow unit has a temperature of at least 75 K below the solidification temperature of the fat.

11. Process according to claim 1, wherein the propellant gas and/or the gas which is supplied to the counterflow unit is liquid nitrogen or gaseous nitrogen which was generated immediately beforehand from liquid nitrogen.

12. Process according to claim 1, wherein the propellant gas has a temperature at or above the solidification temperature of the fat, and in that the gas which is supplied to the counterflow unit is liquid nitrogen or gaseous nitrogen which was generated immediately beforehand from liquid nitrogen.

13. Process according to claim 1, wherein the nozzle is heated at least sectionally to a temperature above the solidification temperature of the liquid fat.

14. Process according to claim 1, wherein the supply line is heated to a temperature above the solidification temperature of the liquid fat.

15. Process according to claim 1, wherein the fat is a plant-based fat or a mixture of at least two plant-based fats.

16. Process according to claim 1, wherein the particles are mixed into a food mass.

17. Device for use in a process according to claim 1, the device having a nozzle whose central channel spans open an inlet opening to which a propellant gas supply line is connected, and a supply line for a liquid discharges, the temperature of which is above its solidification temperature, wherein a source of propellant gas is connected to the propellant gas supply line, wherein the central channel tapers from the inlet opening to a section of smallest radius.

18. Device according to claim 17, wherein the central channel opposite to the inlet opening has an outlet opening which is spanned open by the second section of the central channel, which second section adjoins the section of smallest radius and in which second section the radius increases up to the outlet opening.

19. Device according to claim 17, wherein the central channel opposite to the inlet opening has an outlet opening which is located in the section of the smallest radius.

20. Device according to claim 17, wherein the propellant gas supply line discharges into an annular opening which is limited by the inlet opening and by an annular shoulder spaced therefrom.

21. Device according to claim 17, wherein the distance between the supply line and the annular shoulder limiting the annular opening forms a supply air opening to which only a conduit is connected which supplies recirculated propellant gas.

22. Device according to claim 17, comprising a counterflow unit which is set up to direct a gas flow against the gas flow exiting from the outlet opening of the nozzle.

23. Device according to claim 17, comprising a compressor and by a cooling device coupled downstream of the compressor for recirculation of propellant gas, which has exited from the nozzle, to a propellant gas supply line and/or to the counterflow unit and/or to a conduit connected to a supply air opening.

24. Device according to claim 17, wherein the supply line for liquid and/or the nozzle is heatable to a temperature at or above the solidification temperature of the liquid.

25. Device according to claim 17, wherein the nozzle has a central channel which at its first end forms an inlet opening which is spanned open by a convex face about the longitudinal axis of the central channel, and the central channel tapers to an outlet opening arranged at its opposite second end, wherein the central channel from the inlet opening to a section in which the central channel has the smallest radius is spanned open by a face which is convex to the longitudinal axis and which extends rotationally symmetrically about the longitudinal axis of the central channel, and wherein the central channel terminates in its smallest radius and spans open the outlet opening.

26. (canceled)

27. (canceled)

Description

[0030] The invention is now described in more detail with reference to the Figures, which schematically show

[0031] In FIG. 1 an embodiment of the device according to the invention in top view onto the outlet opening,

[0032] In FIG. 2 the embodiment of FIG. 1 in section A-A,

[0033] In FIG. 3 an embodiment in perspective top view, and

[0034] In FIG. 4 the embodiment of FIG. 3 in section A-A.

[0035] FIGS. 1 to 4 show a nozzle having a rotationally symmetrical central channel 1 that tapers from an inlet opening 3, which is arranged at the first end 2, to a section 4 having the smallest radius 5 of the central channel 1. In the embodiment shown, the central channel 1 has a first section 6 which extends from the inlet opening 3 to the section 4 having the smallest radius 5, and has an adjacent second section 7 in which the central channel 1 widens from the section 4 having the smallest radius 5 to the outlet opening 8 which is spanned open by the central channel 1 at the second end 9. The central channel has a face that is convex to its longitudinal axis.

[0036] At the first end 2 of the central channel 1, an annular opening 10 is formed between the inlet opening 3 and an annular shoulder 11. A propellant gas supply line 12 is connected to the annular opening 10 for supplying propellant gas. Optionally, the propellant gas supply line 12 can be supplied with recirculated propellant gas which is drawn from the gas exiting from the nozzle, e.g. by means of a compressor (not shown), wherein e.g. particles are separated from the gas by means of a separating device (not shown), and the gas is cooled by means of a cooling device (not shown). Alternatively, the propellant gas can generally come from a pressure vessel (not shown).

[0037] A supply line 13 for directing the liquid into the nozzle discharges in the area of the nozzle in which negative pressure is generated by the propellant gas, in this case at a short distance in front of the plane of the annular opening 10 or resp. in front of the inlet opening 3. The supply line 13 can be heatable, e.g. electrically, by means of a controlled heater (not shown).

[0038] In the embodiment shown here, the distance between the supply line 16 for the liquid and the annular shoulder 11, which limits the annular opening 10, forms a supply air opening 14 through which gas from the surroundings can be drawn into the nozzle. Therein, recirculated propellant gas can be directed to the supply air opening 14 by means of a conduit (not shown), alternatively, the supply air opening can be closed or can be accessible only to a connected conduit (not shown) that supplies recirculated propellant gas.

[0039] In accordance with a preferred embodiment, FIGS. 3 and 4 show a counterflow unit 20 which, by way of example, allows 4 partial flows to exit from outlets 21, which are directed against the gas flow exiting from the outlet opening 8. Preferably, a conduit leads propellant gas, which is extracted from the gas flow exiting from the nozzle, to the counterflow unit 20 after separation of particles, preferably after passing through a compressor and a cooling device.

EXAMPLE

Production of Fine Fat Particles from Liquid Fat

[0040] As a representative of a liquid, coconut fat at a temperature of 80 to 90° C. was directed through a supply line of a device that generally corresponded to FIGS. 3 and 4. As a propellant gas, nitrogen, immediately after the evaporation of liquid nitrogen, was directed through the annular opening 10 and was flowed along the convex face of the central channel 1 to the inlet opening 3. The gaseous nitrogen which was used as propellant gas had a temperature of about −60 to −90° C. The outlet opening could be open to the surroundings. Particles of fat having a small particle size were produced. The supply line was heated to approx. 90 to 100° C.

[0041] To prevent deposits of the fat within the nozzle, this was heated to about 200° C.

[0042] Additionally, in one variant, nitrogen, also immediately after the evaporation of liquid nitrogen, was directed through a single outlet 21, in perpendicular against the outlet opening 8 of the nozzle. The outlet 21 was arranged at a distance of approx. 1 to 5 cm from the outlet opening 8.

REFERENCE NUMERAL

[0043] 1 central channel

[0044] 2 first end

[0045] 3 inlet opening

[0046] 4 section

[0047] 5 smallest radius

[0048] 6 first section

[0049] 7 second section

[0050] 8 outlet opening

[0051] 9 second end

[0052] 10 annular opening

[0053] 11 annular shoulder

[0054] 12 propellant gas supply line

[0055] 13 liquid supply line

[0056] 14 supply air opening

[0057] 20 counterflow unit

[0058] 21 outlet