Device and process for the production of fine 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. A process for producing particles from liquid fat having a temperature above its solidification temperature, comprising: conducting liquid fat through a supply line to discharge to an inlet of a nozzle and into an area of a central channel of the nozzle directing propellant gas into the area of the central channel via an annular opening formed between the inlet and an annular shoulder of the nozzle to create a negative pressure, wherein the central channel tapers to a section of smallest radius at the area and comprises a second section that widens to an outlet opening at an opposite end of the nozzle from the inlet, wherein the propellant gas has a temperature of at least 50 K below the solidification temperature of the liquid fat, directing a counterflow of cooling gas into the central channel to cool the liquid fat while it is in the central channel, wherein the cooling gas has a temperature of at least 50 K below the solidification temperature of the liquid fat, discharging a mixture of the propellant gas with the liquid fat from the outlet opening of the nozzle, subsequent cooling of the mixture of the propellant gas with the fat, and separating particles from the propellant gas to obtain the particles.

2. The process according to claim 1, wherein the central channel comprise a convex face that extends to the inlet, extends radially about the longitudinal axis of the central channel and extends symmetrically around the longitudinal axis of the central channel.

3. The process according to claim 1, wherein the propellant gas is directed from an annular supply line into the annular opening.

4. The process according to claim 1, comprising recycling the propellant gas after the separating the particles, wherein the recycling comprises compressing, cooling and recirculating the propellant gas.

5. The process according claim 1, comprising recycling the cooling gas after the separating the particles, wherein the recycling comprises compressing, cooling and recirculating the cooling gas.

6. The process according to claim 1, wherein the propellant gas and/or the cooling gas has a temperature of at least 75 K below the solidification temperature of the fat.

7. The process according to claim 1, wherein the propellant gas and/or the cooling gas comprises liquid nitrogen or gaseous nitrogen which was generated immediately beforehand from liquid nitrogen.

8. The process according claim 1, comprising heating the nozzle at least sectionally to a temperature above the solidification temperature of the liquid fat.

9. The process according to claim 1, comprising heating the supply line to a temperature above the solidification temperature of the liquid fat.

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

11. The process according to claim 1, comprising subsequently mixing the particles into a food mass.

Description

(1) The invention is now described in more detail with reference to the Figures, which schematically show

(2) In FIG. 1 an embodiment of the device according to the invention in top view onto the outlet opening,

(3) In FIG. 2 the embodiment of FIG. 1 in section A-A,

(4) In FIG. 3 an embodiment in perspective top view, and

(5) In FIG. 4 the embodiment of FIG. 3 in section A-A.

(6) 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.

(7) 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).

(8) 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).

(9) 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.

(10) 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

(11) 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.

(12) To prevent deposits of the fat within the nozzle, this was heated to about 200 C.

(13) 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

(14) 1 central channel 2 first end 3 inlet opening 4 section 5 smallest radius 6 first section 7 second section 8 outlet opening 9 second end 10 annular opening 11 annular shoulder 12 propellant gas supply line 13 liquid supply line 14 supply air opening 20 counterflow unit 21 outlet