Food Industry

The centrifuges produced by the company are applied in the food industry

Application of Centrifuges in the Food Industry: A Detailed Technical Overview

Centrifuges are critical unit operations in the food industry for separation, clarification, concentration, and standardization. Their ability to perform these tasks continuously, hygienically, and efficiently makes them indispensable in modern food processing. The choice of centrifuge type is dictated by the specific physical properties of the feed material (solid-liquid ratio, particle size, density difference) and the desired product.

1. Edible Oil Processing

Objective: Extraction and purification of oils from seeds (soybean, rapeseed, sunflower, palm) and subsequent refining.

• a. Application: Oil Slurry Separation (after pressing/solvent extraction)
  • Process Description: After seeds are pressed or treated with a solvent (hexane), the resulting mixture is a slurry of crude oil and solid meal. The centrifuge separates the two phases.
  • Centrifuge Type Used: Decanter Centrifuge (Horizontal Solid Bowl Centrifuge)
  • Technical Rationale: Decanters are ideal for handling feeds with very high solid content (10-30%). The scroll conveyor continuously discharges the de-oiled solid meal (cake), while the clarified crude oil is discharged as the light phase. They are robust and can handle abrasive solids.
• b. Application: Degumming, Neutralization, Bleaching, and Winterization
  • Process Description: These are key refining steps. For example:
    • Degumming: Removal of phospholipids (gums) by adding water or acid.
    • Neutralization: Removal of free fatty acids (FFA) by adding caustic soda.
    • Winterization: Removal of waxes and saturated triglycerides to prevent clouding at low temperatures.
  • Centrifuge Type Used: Disc Stack Separator (Self-Cleaning or Nozzle Type)
  • Technical Rationale: Disc stack separators are perfect for liquid-liquid-solid separation. They efficiently separate the heavy phase (soapstock from neutralization, gums from degumming, waxes from winterization) from the continuous light phase (oil). Self-cleaning models allow for automatic discharge of solids without stopping production, which is crucial for continuous plant operation.

2. Dairy Industry

Objective: Standardization of milk components, separation of cream, and production of specific dairy products.

• a. Application: Skimmed Milk and Cream Production
  • Process Description: The separation of raw whole milk into low-fat milk (skim milk) and cream (fat concentrate).
  • Centrifuge Type Used: Disc Stack Separator (Hermetic Seal)
  • Technical Rationale: Hermetic separators are completely filled, preventing air intake and foam formation, which is essential for protecting milk proteins. The disc stack provides a large surface area for the highly efficient separation of fat globules (cream) from the plasma (skim milk) based on density difference. Modern separators can achieve fat levels in skim milk as low as 0.05%.
• b. Application: Cheese Production (Whey Clarification & Casein Concentration)
  • Process Description:
    • Whey Clarification: After cheese curdling, whey contains valuable proteins but also fine cheese curd fines. Centrifuges clarify the whey by removing these fines before protein concentration.
    • Quark/Curd Concentration: For fresh cheese types like Quark, a centrifuge is used to concentrate the acidified curd.
  • Centrifuge Type Used: Disc Stack Separator (Nozzle or Self-Cleaning) for whey clarification; Quark Separator (a specialized nozzle centrifuge) for curd concentration.
  • Technical Rationale: These specialized separators gently concentrate the delicate protein solids while simultaneously removing the whey, ensuring high yield and product quality.

3. Beverage Industry (Fruit Juices, Wine, Beer)

Objective: Clarification, yield improvement, and stability.

• a. Application: Fruit Juice Extraction and Clarification
  • Process Description:
    • Primary Extraction (Pulp Wash): After initial crushing/pressing, the pulp still contains valuable juice. Decanters are used to wash and extract this remaining juice, increasing yield.
    • Clarification: Removal of suspended solids (pulp, pectin, yeast) to produce clear, stable juices (e.g., apple, clear orange juice).
  • Centrifuge Type Used: Decanter Centrifuge for pulp wash; Disc Stack Separator or Screen Bowl Centrifuge for final clarification.
  • Technical Rationale: Decanters handle the high-pulp feed. For final clarification, high-speed disc stack separators remove extremely fine particles that would otherwise cause haze, often reducing or eliminating the need for filter aids.
• b. Application: Wine & Beer Production
  • Process Description:
    • Wine: Clarification after fermentation (removal of yeast lees), debittering (removal of protein-tannin complexes), and tartrate stabilization.
    • Beer: Removal of yeast after fermentation (cropping) and clarification after filtration (chill-proofing) to prevent haze.
  • Centrifuge Type Used: Disc Stack Separator (Self-Cleaning)
  • Technical Rationale: Self-cleaning disc stack separators allow for continuous, high-throughput processing without interrupting the fermentation or bottling line. They gently handle the sensitive product to avoid extracting harsh compounds or oxidizing the beverage.

4. Starch Industry (Corn, Wheat, Potato)

Objective: Separation of starch from protein (gluten) and fibrous material.

• Application: Primary Separation and Gluten Concentration
  • Process Description: The milled grain or potato is mixed with water to form a slurry. Centrifuges are used in multiple stages:
    1. Primary Separation: Initial separation of starch and gluten from fibrous bran.
    2. Gluten Concentration: Separation of light gluten from heavier starch granules.
    3. Starch Washing: Multi-stage counter-current washing to purify the starch.
  • Centrifuge Type Used: Nozzle Disc Stack Separators and Decanter Centrifuges.
  • Technical Rationale: Nozzle separators continuously concentrate and discharge the starch slurry. The density difference between starch and gluten allows for highly efficient separation in disc stack machines. Decanters are used for streams with higher fiber content.

5. Yeast and Protein Production

Objective: Concentration of microbial biomass (yeast) or protein isolates.

• Application: Yeast Cream Concentration & Cell Harvesting
  • Process Description: After fermentation, the broth contains a low concentration of yeast cells (3-5%). Centrifuges are used to concentrate this into a "yeast cream" (15-20% solids).
  • Centrifuge Type Used: Disc Stack Separator (Nozzle Type)
  • Technical Rationale: Nozzle centrifuges are designed for continuously concentrating biological solids. They can handle high flow rates and achieve the high concentration factors required for efficient downstream processing (e.g., drying, packaging).

Summary of Key Centrifuge Types and Their Food Applications

In conclusion, the selection and application of centrifugation technology are fundamental to the efficiency, quality, and profitability of modern food processing operations. The machines are designed with strict hygiene standards (e.g., complying with 3-A Sanitary Standards) and often feature Clean-in-Place (CIP) systems to meet the rigorous demands of the food industry.