Electrostatic spray chilling of foodstuffs

Patent metadata

Field	Value
Publication number	US-11419340-B2
Application number	US-201916402811-A
Country	US
Kind code	B2
Filing date	May 3, 2019
Priority date	May 3, 2019
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

An electrostatic spray chilling system is configured to rapidly cool foodstuffs. A conveyor traverses foodstuffs through a chilling tunnel. A chilled primary airflow is provided to the chilling tunnel to cool the foodstuffs. As the foodstuff is traversed through the chilling tunnel, spray modules generate and apply sprays of electrostatically charged fluid onto the foodstuff. The charged fluid droplets are attracted to the grounded foodstuff. The charged fluid droplets can be guided onto the foodstuff by secondary fans, configured to generate subflows of the chilled primary air, and by air guiding baffles.

First claim

The invention claimed is:

1. A method of spray chilling, the method comprising:
generating a chilled primary airflow and blowing the primary airflow into a chilling tunnel;
traversing, via a conveyor line, an electrically grounded foodstuff through the chilling tunnel;
generating a charged liquid spray;
applying the charged liquid spray to the foodstuff; and
orienting, via an air guiding baffle, the primary airflow along a first spray axis of a first electrostatic sprayer such that the primary airflow flows generally parallel to the first spray of charged liquid generated by the first electrostatic sprayer, the first spray axis disposed at a first angle relative to vertical.

2. The method of claim 1 , wherein the step of generating the chilled primary airflow includes chilling the primary airflow to a temperature at or below 0° C.

3. The method of claim 1 , wherein applying the charged liquid to the foodstuff includes:
spraying a first spray of charged liquid onto the foodstuff along the first spray axis via the first electrostatic sprayer; and
spraying a second spray of charged liquid onto the foodstuff along a second spray axis, the second spray axis disposed at a second angle relative to vertical via a second electrostatic sprayer.

4. The method of claim 1 , further comprising:
generating, via a first secondary fan, a first subflow of the primary airflow, the secondary fan blowing the first subflow towards the first electrostatic sprayer configured to emit the charged liquid spray.

5. The method of claim 4 , further comprising:
generating, via a second secondary fan, a second subflow of the primary airflow, the second secondary fan blowing the second subflow towards a second electrostatic sprayer;
guiding, via a first baffle, the first subflow along the first spray axis of the first electrostatic sprayer, wherein the air guiding baffle is formed by the first baffle; and
guiding, via a second baffle, the second subflow along a second spray axis of the second electrostatic sprayer.

6. The method of claim 1 , wherein generating the charged liquid spray includes:
charging the liquid to a charge of 20-50 kV.

7. A method of spray chilling, the method comprising:
generating a chilled primary airflow and blowing the primary airflow into a chilling tunnel;
traversing, via a conveyor line, an electrically grounded foodstuff through the chilling tunnel;
generating a charged liquid spray;
generating a secondary airflow and ejecting the secondary airflow from a first electrostatic sprayer to atomize liquid droplets into the charged liquid spray;
heating the secondary airflow prior to ejecting the secondary airflow from the first electrostatic sprayer; and
applying the charged liquid spray to the foodstuff.

8. The method of claim 7 further comprising:
heating the secondary airflow to a temperature of at least 5° C.

9. The method of claim 8 , further comprising:
heating the secondary airflow to a temperature of at least 15° C.

10. The method of claim 7 , wherein generating the secondary airflow and ejecting the secondary airflow from the first electrostatic sprayer to atomize liquid droplets into the charged liquid spray includes:
pressurizing the secondary airflow to a pressure of at least 150 kPa bar to generate a pressurized secondary airflow and ejecting the pressurized secondary airflow from the first electrostatic sprayer.

11. The method of claim 1 , wherein the charged liquid spray includes charged liquid droplets having a diameter of about 20 micrometers.

12. A method of spray chilling, the method comprising:
generating a chilled primary airflow and blowing the primary airflow into a chilling tunnel;
traversing, via a conveyor line, an electrically grounded foodstuff through the chilling tunnel;
generating a charged liquid spray;
applying the charged liquid spray to the foodstuff; and
activating an electrostatic sprayer based on a hook detector detecting the foodstuff entering a spray area of the electrostatic sprayer.

13. The method of claim 12 , further comprising:
deactivating the electrostatic sprayer based on the foodstuff exiting the spray area.

14. A spray chilling system comprising:
a primary blower configured to generate a chilled primary airflow;
a conveyor line configured to traverse electrically grounded foodstuff within a chilling tunnel;
a plurality of spray modules disposed along the conveyor line and configured to spray charged liquid onto the foodstuff, wherein a first spray module of the plurality of spray modules comprises:
a first electrostatic sprayer configured to spray a first charged liquid spray onto the foodstuff; and
a first secondary fan disposed between the first electrostatic sprayer and the primary blower, the first secondary fan configured to generate a first subflow of the chilled primary airflow and blow the first subflow towards the first electrostatic sprayer.

15. The spray chilling system of claim 14 , wherein the first spray module further comprises:
a first air baffle disposed proximate the first electrostatic sprayer and oriented to guide the first subflow along a first spray axis of the first electrostatic spray gun.

16. The spray chilling system of claim 15 , wherein the first spray module further comprises:
a second electrostatic sprayer configured to spray a second charged liquid spray onto the foodstuff;
a second secondary fan disposed between the second electrostatic sprayer and the primary blower, the second secondary fan configured to generate a second subflow of the chilled primary airflow and blow the second subflow towards the second electrostatic sprayer; and
a second air baffle disposed proximate the second electrostatic sprayer and oriented to guide the second subflow along a second spray axis of the second electrostatic spray gun.

17. The spray chilling system of claim 16 , wherein the first electrostatic sprayer is disposed on a first side of the conveyor line and the second electrostatic sprayer is disposed on a second side of the conveyor line.

18. The spray chilling system of claim 17 , wherein the first spray axis is oriented towards the conveyor line relative to vertical and the second spray axis is oriented towards the conveyor line relative to vertical.

19. The spray chilling system of claim 14 , further comprising:
a pneumatic line extending to a first electrostatic spray gun to provide compressed air to the electrostatic spray gun, the first electrostatic spray gun configured to eject the compressed air as a secondary airflow to atomize the first charged liquid spray; and
a heater disposed on the pneumatic line to heat the compressed air such that the secondary airflow is warmer than the primary airflow.

Assignees

• Graco Minnesota Inc
• Van Laer Hubertus J

Inventors

• Clerx Bart
• Van Laer Hubertus J

Classifications

• A23B2/803

  Materials being transported through or in the apparatus, with or without shaping, e.g. in the form of powders, granules or flakes · CPC title

• A23B4/062 Primary

  the materials being transported through or in the apparatus with or without shaping, e.g. in the form of powder, granules or flakes (moving on the spot only A23B4/066) · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title

• A23B4/08 Primary

  with addition of chemicals {or treatment with chemicals} before or during cooling {, e.g. in the form of an ice coating or frozen block} · CPC title

• A23B4/30

  by spraying of liquids · CPC title