Food Product Coating Using Cryogenic Sub-Cooling and Gravity Flow

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Solution Overview

Problem

Existing food coating methods result in appearance defects, mechanical stress on products, and unwanted sauce particles due to mechanical mixing and refrigerant injection, leading to poor visual appearance and inefficient coating control.

Innovation Solution

A method involving sub-cooling food products in a hopper with a cryogenic fluid before contact with the coating substance, using a hollow screw and cryogenic injection, followed by contact without additional refrigeration, allowing the coating to freeze via thermal transfer from the sub-cooled products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If mechanical mixing and refrigerant injection are used in a rotating tank, then the coating process can be carried out, but appearance defects and mechanical stress on products occur

Engineering Contradiction:
Improvecoating process efficiencyVSAvoidappearance defects and mechanical stress
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes the rotating tank and mechanical mixing blades from the coating system. Instead of mechanically mixing the coating substance with rotating blades, the product is conveyed through a stationary hopper where coating occurs during gravity-driven flow, eliminating mechanical stress and appearance defects while maintaining coating efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical mixing system (rotating tank with blades) with a gravity-based flow system. The product moves through the hopper under gravity, and coating substance is applied without mechanical agitation, substituting mechanical action with gravitational flow to eliminate harmful mechanical stress

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If refrigerant is injected along the axis of the rotating tank, then the coating substance can freeze around products, but unwanted sauce particles (fines) are frozen away from products

Engineering Contradiction:
Improvecoating controlVSAvoidunwanted sauce particles or fines
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The invention removes the axial refrigerant injection system from the rotating tank. Instead, refrigerant is injected at the base of the stationary hopper, creating a cold zone where coating freezes only on product surfaces during gravity flow, preventing formation of unwanted frozen sauce particles away from products

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a cold air stream as an intermediary medium. Refrigerant cools the base air which then rises and contacts the flowing product, providing controlled freezing of coating on product surfaces without directly freezing loose sauce particles in the coating zone

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If pre-cooled and pre-frozen products are introduced into the rotating tank with sauce injection, then gradual coating occurs, but the process creates mechanical stress and appearance defects

Engineering Contradiction:
Improvecoating homogeneityVSAvoidmechanical stress and appearance defects
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention replaces mechanical mixing and tumbling with a gravity-driven vertical flow system. Pre-cooled products flow downward through the stationary hopper under gravity, receiving coating substance along the flow path, achieving uniform coating without mechanical stress or appearance defects

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention transitions from horizontal rotating tank mixing to vertical gravity flow. Products move vertically downward through the hopper while coating is applied along this vertical trajectory, creating uniform coating through gravitational flow rather than mechanical tumbling

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Improves visual appearance and coating homogeneity, reduces mechanical stress, and eliminates unwanted particles, achieving better control over the coating process.

Implementation Method 1

sub-cooling by supplying external frigories to a temperature lower than their initial temperature

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the coating around the products being frozen under the action of the transfer of frigories from the sub-cooled products to said coating substance

Methodology Applied
Scientific EffectThermal transfer: Conduction (thermal)

Data Source

PatentEP3905890B1Method and installation for coating food products
Publication Date: 2025.09.03 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP3905890B1 patent drawingFigure 1

AI summary

Method and installation for coating food products with a coating substance, of the type comprising a step of bringing the food products into contact with the coating substance, and wherein, before the food products and the coating substance are brought into contact, the food products are sub-cooled by providing external cold energy at a temperature lower than their initial temperature, and wherein the food products and said coating substance are then subsequently brought into contact without providing external cold energy, the coating around the products being fixed under the action of the transfer of cold from the sub-cooled products to said coating substance, characterized in that the sub-cooling of the products is carried out in a hopper (10), capable of being supplied with product to be coated, which hopper is provided with means for supplying a cryogenic fluid, the hopper being provided at its lower part with a hollow screw (11) provided with turns allowing the product to be poured out of the hopper to the step of bringing the food products into contact with the coating substance, said means for supplying a cryogenic fluid into the hopper comprising an injection pipe (12), for example of the perforated-manifold type with multiple orifices, which is positioned inside the turns of the hollow screw, extending in a direction substantially parallel to the axis of the screw.