What is a shear pump?
A shear pump is a pump and a rotor-stator mixer in one machine. It sits in the process line, moves the product along, and shears it between its rotor and stator at the same time. It is also known as a high shear pump, a shearing pump, a pump shear unit, a shear mixer pump or an inline shear pump, and it works as a mixing pump wherever a product has to be moved and processed in one step.
How it is built:
- Rotor and stator, mounted concentrically. The pump has a concentrically mounted set of rotor and stator, with a minimal tolerance between them.
- Single-stage, four-blade axial rotor that turns at high speed inside the stationary stator.
- Four stator heads to choose from (see below).
- Precision work head. The rotor/stator work head is precision engineered; the minimal tolerance gives finer results.
- High flow rates and high-viscosity lines. Wahal shear pumps give high flow rates and can process high-viscosity lines.
How a shear pump works
The shear pump working principle, step by step:
- Intake and acceleration. The rotor is mounted on the main spindle and turns at high rpm. The high centrifugal force this creates throws the product outwards, to the stator walls.
- Shear. The rotating blades pass the openings in the stator. Because the tolerance between rotor and stator is very small, the particles are mechanically sheared.
- Discharge. The material is expelled through the stator at high speed into the mix, which creates intense hydraulic shear.
- Pumping. The same centrifugal action that throws the product through the stator also pumps it, so the shear pump moves the product along the line while it shears it.
How fine the result is depends on the stator head fitted.
Rotor and stator heads
Every Wahal shear pump uses a four-blade axial rotor. It is combined with one of four stator heads:
| Stator head | Openings |
|---|---|
| General mixing head | Holes |
| Mixing head | Square holes |
| Disintegrating head | Slots |
| Emulsion screen head | Fine holes |
Across our rotor-stator machines, the stator is chosen to suit the particle size required, from general mixing heads to slotted disintegrating heads and fine emulsion screens. We use CFD analysis to select the right mixer and stator design for each process.
What a shear pump is used for
A shear pump is used where a product has to be pumped and processed in the same step. The jobs it does:
- emulsifying and homogenizing
- blending and dispersing
- hydrating and dissolving
- suspending
- particle size reduction and de-agglomeration
- disintegrating solids
- reclamation
In Wahal plants:
- Tomato ketchup. In our tomato processing plant, the shear pump does the pumping and shearing step of the processing section, alongside the multiprocessor and the inline homogenizer.
- Mayonnaise. The shear pump is one of the machines for a mayonnaise processing plant.
Shear pump, inline homogenizer or batch homogenizer?
Wahal builds all three. They use the same rotor-stator principle but do different jobs.
| Shear pump | Inline homogenizer | Batch homogenizer | |
|---|---|---|---|
| Where it works | In the line | In the pipeline or a recirculation loop | Inside the vessel |
| Main job | Pumping and shearing in one unit | Emulsifying, dispersing, dissolving and particle size reduction, in a single pass or on a recirculating batch | Processing a batch in the vessel |
| Rotor-stator | Single-stage, four-blade rotor; 4 stator heads | 1, 2 or 4 rotor-stator stages; 20+ designs | Designed to the length and diameter of your vessel |
| Capacity | High flow rates; high-viscosity lines | 15 to 200,000 L/hr | Built to vessel size; hydraulic lift available |
| More | This page | Inline homogenizer | Batch homogenizers |
For the full rotor-stator range, including bottom-mounted and laboratory models, see our high shear mixer page. To compare every inline machine we make, including powder induction mixers, see inline high shear mixers.
Test your product before you buy
There's no better way to test a machine than on your own product. You can run a trial in our fully equipped laboratory and see the results you get, and how fast. If you need longer, our rental program lets you keep a machine, pre-configured to your requirements, for as long as you need. See trials and rentals.
Wahal Engineers makes shear pumps in India, at our factory in Bhigan (Murthal), Sonipat, Haryana. Tell us your product, its viscosity and the job the pump has to do, and we will recommend a machine.
Frequently asked questions
What is a shear pump?
A pump and a rotor-stator mixer in one inline unit. It moves liquids and semi-solids along the line and shears them between a high-speed rotor and a stationary stator. It is also called a high shear pump.
How does a shear pump work?
The rotor, mounted on the main spindle, turns at high rpm. Centrifugal force throws the product to the stator walls. As the four rotor blades pass the stator openings, the very small tolerance between rotor and stator shears the particles, and the product is expelled at high speed, which pumps it and creates intense hydraulic shear.
What is the difference between a shear pump and an inline homogenizer?
Both are inline rotor-stator machines. The shear pump has a single-stage, four-blade rotor and four stator heads, and its job is to pump and shear in one unit, including on high-viscosity lines. An inline homogenizer has one, two or four rotor-stator stages and over twenty stator designs, and is used to emulsify, disperse and reduce particle size at 15 to 200,000 L/hr.
Can a shear pump handle viscous products?
Yes. Wahal shear pumps give high flow rates and have the capacity to process high-viscosity lines.
Which stator heads are available?
Four: a general mixing head (hole type), a mixing head (square hole type), a disintegrating head (slotted type) and an emulsion screen head (fine hole type). All are used with a four-blade axial rotor.
Can I test a shear pump on my product before buying?
Yes. Trials run in our fully equipped laboratory, and our rental program lets you keep a machine, pre-configured to your requirements, for as long as you need.
