Yuy-z Sanitary Rotary Cam Pump Working Principle And Selection Guide

The YUY-Z sanitary lobe pump is engineered specifically for shear-sensitive food products like yogurt, fruit juice, and cream, where standard centrifugal pumps would degrade texture and quality. Its non-contacting rotors operate at low speeds, preserving cellular structure and preventing emulsion breakdown. The pump handles viscosities up to 1,000,000 cP while maintaining flow rates independent of discharge pressure, making it suitable for everything from thin beer to thick dough.

Operating Principle

The rotary lobe pump uses externally timed gears to drive two rotors in opposite directions, preventing metal-to-metal contact. As rotors unmesh at the inlet, expanding volume creates a partial vacuum that draws product into the pumping cavities. The fluid travels between lobe tips and the casing wall, then discharges as lobes re-mesh.

The sanitary lobe pump operates at lower speeds than other positive displacement designs, minimizing shear forces on suspended solids. This gentle action preserves product texture, prevents emulsion breakdown, and protects fragile ingredients. The non-contacting rotor design allows passage of soft solids without damage.

Technical Specifications

Applications in Food Processing

• The lobe gear pump handles beer, fruit juice, and wort without generating heat or shear that affects flavor stability. Low rotational speed ensures consistent product temperature. Smooth internal geometry prevents foaming and aeration.

• The sanitary lobe pump processes yogurt, cream, butter, and curdled milk without breaking structure. Bi-wing rotor options handle delicate curds without degradation.

• For dough, fondant, creams, and chocolate, the gear lobe pump provides uniform flow without smashing particulates, handling high-viscosity materials at reduced speeds.

Operational Workflow

1. Product enters through suction port as rotors unmesh.

2. Cavities fill with product between lobe tips and casing.

3. Rotors carry product around casing interior.

4. Rotors re-mesh at discharge port, forcing product out.

5. Flow reverses by changing rotor rotation direction.

CIP cleaning follows standard procedures without disassembly. The front pull-out design simplifies rotor and seal replacement, reducing downtime.

Performance Factors

Output from the rotary lobe pump is directly proportional to rotor speed, with discharge pressure having minimal effect on flow rate. This positive displacement characteristic ensures consistent transfer rates independent of downstream variations. Single mechanical seals (SiC/SiC or TC/TC) contain product without leakage. Double mechanical seals provide sterile barriers for aseptic applications.

Maintenance

• Rotor inspection: check wear on lobe tips and casing contact areas.

• Seal replacement: front-loading design allows change without removing pump head.

• Bearing service: L10 bearings provide minimum 20,000-hour service life.

• Surface verification: measure Ra values to confirm ≤0.8 µm specification.

How the Pump Preserves Product Integrity

The YUY-Z sanitary lobe pump achieves gentle handling through three interrelated design elements: 316L stainless steel construction provides corrosion resistance and cleanability; the Ra ≤ 0.8 µm electropolished surface prevents bacterial adhesion and product fouling; and the non-contacting rotor geometry eliminates metal-to-metal contact, allowing soft solids to pass without crushing. This combination makes the lobe pump suitable for products where texture, particle integrity, and visual appearance directly affect market value.

Selection Guidelines

Match flow rate and pressure requirements against pump curves. Consider viscosity range and solids passage for rotor selection (bi-wing for large solids, tri-lobe for general use). Verify seal compatibility with product and cleaning chemicals. Confirm surface finish specifications for sanitary applications.

Pre-installation testing on product samples validates pump suitability. Speed adjustments optimize shear reduction while maintaining required flow.

1. Match rotor type to product – bi-wing for fragile solids, tri-lobe for general viscous fluids.

2. Verify seal material compatibility with product and CIP chemicals.

3. Confirm surface finish documentation (Ra ≤0.8 µm standard, ≤0.5 µm optional).

4. Validate CIP/SIP procedures with the pump configuration.

These practices ensure reliable sanitary pumping. Properly specified YUY-Z sanitary lobe pumps deliver long-term performance in food and beverage applications with minimal product degradation.

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Introduction to sanitary rotor pump:

The YUY-Z series sanitary rotor pump is a kind of rotary displacement pump specially used to convey products of high viscosity researched and developed by Yuanya Company. It is mainly applied in such industries as food,bewerage,chemical industry，medicine,etc. By integrating the latest sanitary design concepts,the products can meet the increasing requirements for sanitation and cleanliness in different service conditions.

Specialized manufacturing technology and machining precision of the products have reached internationally advanced level，making their quality more stable with high efficiency and good safety，and becoming the preferred choice of clients all over the world.

The sanitary rotor pump is a kind of displacement pump，which is also called cam pump,colloid pump,three-vane pump and universal conveying pump. It realizes the purpose of conveying fluids through periodic transformation of multiple fixed volume conveying units inside the working chamber.

Working principle of sanitary rotor pump:

As shown in the figure, due to continuous movement of the two rotors, the media are transported to the discharging port in the volume flow direction through the rotor, and then are removed after pressurization.

It can be seen that the faster the rotation speed of the two rotors，the greater the flow rate of the pump.Therefore, the pump flow rate is directly proportional to the rotor rotation speed. If the rotation direction of the two rotors is changed,the cam pump can convey the media in a reverse direction without damaging the parts.

Classification of sanitary rotor pump:

At present,the sanitary rotor pumps can be roughly classified into two types according to the structural form: those with a vertical structure and those with a horizontall structure.As shown in figure A, the inlet and outlet of the pump are parallel to the horizontal direction,and the center line of the two rotors is perpendicular to the horizontal direction.This structure is called a horizontal structure.The vertical structure is opposite to the horizontal structure. The inlet and outlet are perpendicular to the horizontal direction, and the center line of the two rotors are parallel to the horizontal direction, as shown in figure B.

In practical applications,the horizontally-structured sanitary rotor pump is generally used. Since the inlet and outlet are horizontal, it is beneficial for the connection with pipes,and the working efficiency is high. Because the sanitary rotor pump with a verticall structure takes less space, this type of structure will allso be selected in a specific working environment.

Features of sanitary rotor pump:

1. Sanitary and safe

The streamlined structure of the rotor and the pump body cavity are flat and smooth without any dead corner of residues.

There are O-ring seals at both ends of the rotor and shaft to effectively prevent materials from entering the gap between the shaft and shaft hole. The parts contacting the materials are made of stainless steel that meets hygienic standards, and the sealing rubber is non-toxic rubber.

There is a mechanical seal and an oil seal between the pump body and gear box,and the oil stain will not enter or splash into the pump chamber to ensure sanitary and safe transportation of media.

2.Long service life

During the use,there is no hard collision and metal friction between rotors and between the rotor and pump chamber of the rotor pump,so as to improve the service life.

Due to high manufacturing precision, the vibration is small, the operation is stable, and the service life of the seal is increased correspondingly.

Heavy-duty bearings of first-line brands are purchased and helical gears are subject to fine grinding and heat treatment to achieve long life and low noise.

3.Wide application range

The shearing force on the conveyed media is small, and the rotor rotation speed is generally 40-400r/min.The sanitary rotor pump can convey media with a wide range of viscosities as well as fluids with viscosities up to 2 million CP.

Due to the reasonable gap design between the two rotors,the suspension, solid particles and easily crystallized fluids in the conveyed media can be safely transported through the gap.

After equipped with a frequency converter, it can realize control of flow rate and can serve as a common metering pump.

The mobile pump can pump a variety of barreled materials with a suctionvacuum of-0.08MPa.

4.Highly efficient, energy saving and environment-friendly

Practice has proved that the power consumption of the sanitary rotor pump is equivalent to 50%-70% of that of other pumps of its kind,saving social energy.

The gap between rotors and between the rotor and pump chamber of the sanitary rotor pump is small.Even if fluids of low viscosity are conveyed, the return flow generated is small (the return flow is proportional to the gap)，which makes the pump flow more stable, the efficiency higher and the suction force better.

 

Installation requirements

1.The inner diameter of the inlet pipe must be one size larger than the inlet diameter of the rotor pump.The inner diameter of the outlet pipe must be equal to or larger than the inner diameter of the rotor pump outlet.

2.It is strictly forbidden to use a Y type filter or pipeline filter. The effective filtration area of the filter should be more than 2 times larger than the inlet diameter of the pump.

3.The horizontal installation distance of the pump inlet is within 3 meters. It is strictly forbidden to install and use a civil ball valve (its stability is poor and its plug diameter is too small).

Rotor Vane Quantity Selection Reference

Driving configuration

Driving configuration

Sanitary rotor pump head structure and description of parts：

The sanitary rotor pump head is mainly composed of two same rotors,twodriving shafts, pump body, gear box, etc.

Description of parts：

Displacement of sanitary rotor pump

The displacement of the sanitary rotor pump refers to the volume of the media discharged after the two transmission shafts in the pump drive the two rotors to rotate for one cycle,which is usually expressed in such units as ml/r,L/r,etc.The displacement of the sanitary rotor pump depends on the geometric volume of the internal closed cavity.The internal structural sizes of pumps installed with different shapes of rotors are different, so the displacement is also different.

Flow rate of sanitary rotor pump

1.Theoretical flow rate

The theoretical flow rate refers to the volume of the media conveyed in unit time during the working process of the sanitary rotor pump without considering the leakage loss, which is:

Theoretical flow rate = displacement X rotation speed X time

2.Actuall flow rate

The actual flow rate refers to the value calculated after considering the leakage loss during the working process of the sanitary pump.Generally, the volumetric efficiency is between 80% and 90%.

Actual flow rate = theoretical flow rate X volumetric efficiency

Performance selection table：