Industry-Knowledge

Twin-Screw Sanitary Pumps for Food Processing

1. Industry Pain Points & Product Positioning

Food production has strict dual requirements for material taste retention and food hygiene safety. Most traditional pumping equipment cannot balance process performance and sanitary compliance, resulting in unstable product quality and unqualified workshop sanitation.
The main pain points in the food industry are summarized as follows:
  • Material sensitivity damage: Fruit grains, dairy colloid, cream structure and food flavor are easily destroyed by high-shear stirring, causing product stratification, foaming, poor taste and color difference.

  • Sanitary hidden dangers: Dead corners and residual materials lead to mildew, bacterial proliferation and cross-contamination, failing food safety inspection.

  • Viscosity adaptation limitations: Traditional pumps struggle to switch freely between low-viscosity beverages and ultra-high-viscosity pastes and greases.

  • Unstable process accuracy: Pulsating flow leads to inaccurate filling weight and inconsistent batching ratio, affecting batch stability.

  • Difficult sterilization and cleaning: Complex structures cannot support full CIP automatic cleaning, resulting in high manual cleaning costs and residual risks.

Product Core Positioning: The food-grade sanitary twin screw pump is a low-shear, residue-free, fully sterile and wide-viscosity adaptable conveying equipment, specially designed for refined food processing scenarios that require protecting food texture, flavor and sanitary safety.

2. Definition & Working Principle

2.1 Professional Definition

The food sanitary twin screw pump is a rotary positive displacement pump driven by external synchronous gears. The two conjugate stainless steel screws rotate synchronously with zero metal contact and zero friction. It relies on continuous closed volume cavities to realize integral translational conveying of food materials, achieving low-pulsation, ultra-low shear and zero-residue fluid delivery that meets food-grade sanitary standards.

2.2 Working Principle

Driven by an independent synchronous gearbox, the twin screws mesh to form continuously sealed moving cavities. Food materials are completely locked in the cavities and move axially from the inlet to the outlet in an integral laminar flow state.
Different from the stirring and crushing conveying of centrifugal pumps, the twin screw pump realizes pure push-type conveying without turbulence, impact or shearing destruction. The reversible rotation function supports forward material feeding and reverse residual material recovery, which effectively reduces food waste and meets the flexible process requirements of food production lines.

3. Food Exclusive Structural Design (Sanitary & Anti-Residue Core)

3.1 Food-Grade Full Sanitary Material System

All wetted parts strictly comply with international food safety certifications including FDA, 3-A and EHEDG:
  • Flow-through material: 316L / 1.4404 medical and food-grade stainless steel, anti-corrosion, anti-oxidation, no metal precipitation.

  • Inner surface treatment: Mirror electrolytic polishing Ra≤0.4μm, non-stick oil, non-stick sugar, non-stick paste, effectively avoiding material residue and bacterial adhesion.

  • Food-grade sealing:

  • EPDM: Suitable for beverages, sugar liquid and aqueous food materials;

  • HNBR: Adapt to high-temperature edible oil and high-temperature paste working conditions;

  • Food-grade FKM: Resistant to sugar scaling, oil pollution and acid-base cleaning liquid.

3.2 Zero-Contact Screw Rotor Structure

The twin screws are driven by external synchronous gears without any contact or friction during operation. There is no metal wear debris pollution, and no rubber parts directly contact food materials. It fundamentally avoids odor absorption, color migration and material deterioration risks existing in single screw pumps, meeting the long-term continuous production requirements of high-standard food workshops.

3.3 Streamlined Zero-Dead-Corner Pump Cavity

The integral streamlined pump body has no right-angle dead corners, no hidden grooves and no residual blind holes. The fully smooth flow channel ensures that no food raw materials such as jam, grease and starch paste remain after shutdown, completely solving the problems of mildew deterioration and cross-contamination caused by residual materials in traditional pumps.

3.4 Sanitary Quick-Assembly Structure

Standard sanitary tri-clamp interface is adopted, which is consistent with the mainstream food pipeline connection standard. It supports quick disassembly and manual cleaning, and cooperates with automatic CIP cleaning system to realize full-process sterile production.

4. Core Advantages for Food Processing Industry

4.1 Ultra-Low Shear to Protect Food Texture & Flavor

It completely avoids material damage caused by high shear force: does not break fruit grains and food fibers, does not delaminate dairy colloid, does not damage cream fluffy structure, and does not cause foaming and flavor loss of beverages. It perfectly retains the original taste, color and hierarchical texture of food, greatly improving product appearance and consumer experience.

4.2 Full Sanitary & Zero-Pollution Performance

Full metal flow channel without rubber contact with materials, no precipitation, no odor migration, no microbial growth. It supports high-temperature SIP steam sterilization and fully closed CIP circulating cleaning, which can pass GMP food safety audits and food factory hygiene acceptance stably for a long time.

4.3 Zero-Pulsation Stable Conveying & High Precision Batching

Constant flow and pressure output without fluctuation, ensuring accurate filling weight and stable batching ratio of food production lines. It effectively solves the problems of uneven finished product quality and large batch difference caused by pulsating flow of lobe pumps and other equipment.

4.4 Ultra-Wide Viscosity Adaptability

It covers all food viscosity ranges from 1 cPs low-viscosity drinking water and beverage to 1,000,000 cPs ultra-high viscosity chocolate paste, butter, sesame paste and starch paste. One pump can adapt to multiple working conditions of the food workshop, reducing equipment procurement and maintenance costs.

4.6 Strong Particle Passing Capacity

The wide-flow screw profile is specially designed for food particle working conditions, which can completely and smoothly pass soft food particles such as fruit grains, vegetable grains and meat grains without extrusion and crushing, ensuring the integrity of granular food raw materials.

5. Comparison With Traditional Food Pumps

Pump Type
Advantages
Disadvantages in Food Processing
Centrifugal Pump
Low cost & large flow
High shear, serious foaming, particle breaking, material delamination, poor for refined food
Single Screw Pump
High self-priming & low speed
Rubber stator contacts food directly, easy odor absorption, residue mildew, unable for high-standard sterile food
Lobe Pump
Simple structure
Strong flow pulsation, easy to crush particles, large wear, unstable filling accuracy
Sanitary Twin Screw Pump
Ultra-low shear, zero residue, zero pulsation, full sterile, particle protection
Slightly higher manufacturing cost, suitable for high-end refined food production

6. Full Industry Application Scenarios in Food Processing

6.1 Beverage & Juice Industry

Fruit grain beverage, mango puree, lychee pulp, concentrated fruit juice, tea extract liquid, sugar syrup, functional beverage raw liquid, avoiding foaming and fruit grain breaking.

6.2 Dairy Industry

Yogurt, lactic acid bacteria liquid, fresh milk, cream, condensed milk, ice cream base material, dairy emulsified liquid, preventing emulsion delamination and active ingredient loss.

6.3 Condiment Processing Industry

Tomato paste, chili sauce, bean paste, peanut butter, sesame paste, oyster sauce, thick soup seasoning, viscous fermented condiment, no residue and no stratification.

6.4 Baking & Confectionery Industry

Chocolate slurry, maltose, cream filling, fruit filling, pectin, starch paste, high-viscosity sugar material stable conveying.

6.5 Edible Oil & Grease Industry

Edible vegetable oil, palm oil, lard, butter, high-viscosity grease, waste oil recovery and conveying.

6.6 Pre-made Food & Deep Processing Industry

Meat paste, fish paste, food filling, seasoning slurry, semi-finished viscous food raw materials, protecting food organizational structure.

6.7 Aseptic Batching & Filling Process

Precision proportional batching, aseptic quantitative filling, circulating conveying of refined production lines, ensuring stable batch quality.

7. Standard Technical Parameters

  • Applicable Viscosity: 1 cPs ~ 1,000,000 cPs

  • Flow Range: 0.3 ~ 120 m³/h

  • Working Pressure: 0.2 ~ 1.6 MPa

  • Working Temperature: -10℃ ~ 95℃, instantaneous 135℃ SIP high-temperature sterilization

  • Sanitary Standard: FDA / 3-A / EHEDG / GMP compliant

  • Surface Roughness: Ra ≤ 0.4μm

  • Flow State: Zero pulsation, stable laminar flow

  • Cleaning Method: Fully automatic CIP online cleaning & SIP sterilization

  • Particle Passing: Complete passage of soft food particles without crushing

8. Standard Operation & Maintenance Specifications for Food Workshops

  • No Dry Running: Dry running is strictly prohibited to avoid sealing damage and sanitary risks.

  • Low-Speed Conveying for Particle Materials: Reduce operating speed when transporting fruit grains and meat grains to ensure material integrity.

  • Daily CIP Cleaning: Complete acid-base circulating cleaning and sterile water rinsing after shutdown to avoid sugar dirt, oil dirt and bacterial growth.

  • Regular Seal Inspection: Replace aging food-grade seals regularly to prevent medium leakage and sanitary hidden dangers.

  • High-Temperature Material Matching: Select HNBR high-temperature resistant seals for high-temperature grease and hot paste working conditions.

9. Common Industry Misconceptions Correction

  • Misconception 1: Centrifugal pumps are sufficient for ordinary food conveying.        Correction: Centrifugal pump high shear will damage food taste, cause foaming and delamination, and cannot meet refined food production standards.

  • Misconception 2: Single screw pumps are more suitable for food processing.        Correction: Rubber stator of single screw pump contacts food directly, which is prone to odor absorption, color migration and residual mildew, and is gradually eliminated in high-end food workshops.

  • Misconception 3: Particle materials cannot be transported by twin screw pumps.        Correction: Food-grade wide-flow twin screw pump is specially designed for granular materials, which can protect particle integrity without breaking.

  • Misconception 4: Low-viscosity beverages do not need low-shear pumps.        Correction: Beverages are sensitive to foaming and flavor loss. Only ultra-low shear twin screw pumps can ensure stable taste and quality.