Grinding & Refining Machinery

Texture is a specification, not a preference. A sauce that separates on the shelf, a nut paste that feels gritty, a filling that will not hold its shape in the pack — all three are particle-size problems, and all three are set by the machine that does the refining.

What wet grinding and refining machinery does

Grinding and refining work on wet products. The material is drawn into a narrow gap between a fast-spinning rotor and a fixed stator, and the shear in that gap cuts particles down and forces immiscible phases into emulsion.

This is mechanically different from a blender or a colloid-style mixer. A blender moves the whole batch around a blade; the product is stirred and partly reduced. A mill holds the product in the working gap, which is why the result is repeatable from batch to batch rather than dependent on how long someone leaves the machine running.

The functions this covers on one head:

• Dispersion — breaking agglomerates apart and wetting them out

• Refining — reducing particle size to a set fineness

• Emulsifying — holding oil and water phases together

• Homogenising — evening out the result across the batch

What to check before you specify

Target fineness. This is the first constraint. Fineness is set by the working gap and the rotor speed, and it has to be achievable on the product you actually run, not on a bench sample of water.

Capacity and viscosity. Capacity figures are usually quoted on a water basis, which is the easiest case. Thicker products move through the same gap more slowly, so a viscous paste often points to a larger frame than the hourly volume alone suggests.

Feed and discharge arrangement. Whether the mill draws from a kettle, a hopper or a tank determines a lot of the installation. Units that run as part of a continuous process need to be fed at a steady rate rather than in batches.

Power supply. Smaller mills in our range can run on single phase. Everything larger needs three-phase supply, which affects where the machine can be placed.

Cleaning and changeover. Where several products run on one mill, the milling chamber has to open for washing between batches so flavour carries over as little as possible.

Where it sits in a process

A mill is normally specified after the product has been cooked or combined, and before filling or packing. In a sauce process it sits downstream of the cooking stage, taking product from a cooking kettle or mixer and passing it on to filling.

Nut and seed pastes are the classic two-stage case: a coarse pass to break the material down, then a finer pass to reach the final texture. Where a plant runs both, the same mill family can often cover both passes by changing the model rather than the technology.

Our JM series colloid mill is the current unit in this category, covering seven models from 0.01 to 10 tonnes per hour and 1.5 kW to 18.5 kW, with fineness held between 2 and 40 microns across the range.

FAQ

Is a colloid mill the same as a blender?

No. A blender stirs the batch; a mill holds the product in a working gap between rotor and stator, which is what makes the reduction repeatable.

Can one machine cover several products?

Usually yes, where the products are similar in viscosity and the required fineness is within the machine's range. Confirm both before committing.

How fine can wet grinding go?

On the JM series the range is 2 to 40 microns. The achievable figure for a specific product depends on viscosity, solids content and how the gap is set.

Do I need a pump?

It depends on how the mill is positioned and how thick the product is. Mills fed from a kettle or hopper often need no pump; mills placed away from the source usually do.

Can I run it on single phase?

Only on the two smallest models. Every larger model requires three-phase supply.