Here are the main vessel types in our grease plant projects.
We generally use two systems to make soap-based grease, depending on the plant’s capacity. Smaller plants are based on a single kettle that does both the saponification and the finishing and the larger plants use an autoclave or saponification kettle to do the first half of the process, in conjunction, generally, with two finishing kettles where the dilution base oils and additives are introduced.
Our process vessels are built by UK manufacturers who work as our subcontractors to our designs. If the circumstances demand we can outsource from other countries, depending up the quality and reliability of the company concerned.
This uses a contra-rotating vessel with higher powered agitation on the inner paddle to increase the reaction rate and completion. It can either be a pressurised vessel or one operating at atmospheric pressure, depending on what type of grease is being made. An atmospheric vessel costs less and requires fewer ancilleries but is a bit more restricted in what it can make quickly. The heating jacket is normally zoned to allow half size batches. Variable speed inverter drives are used to allow the agitation to be slowed down for more shear sensitive products.
If required, we can source grease contactors, which have a faster heating rate due to the inner heating wall. They are good for high volume manufacture of a small number of types of grease, but the annular space between the inner heating wall and the outer wall is difficult to clean making it more difficult for manufacturing a wide variety of greases from the same vessel. Also, there have been occasions when the annular space becomes blocked with grease that refuses to flow round during complex grease manufacture.
This normally uses a contra-rotating atmospheric vessel with a dual zoned jacket to allow smaller batches to be made. The inner paddle has slightly raised power and speed to allow the kettle to double as a complete batch grease kettle, if the need arises. The variable speed inverter on the inner paddle wold be sped up for saponification in this situation or slowed down for finishing.
Bottom End Dispersion and Turbo Mixing
Complexing a grease can be done more effectively with a bottom mounted dispersion unit, which prevents the build up of partly reacted soap at the bottom of the batch. We have supplied a turbo mixer (high power bottom entry turbine plus gate) and on another occasion, a contra-rotating system with an additional blade at the bottom for this purpose. We can also offer a triple motion system which uses a low speed gate or anchor, medium speed inner agitator and high speed bottom agitator.
We can also offer a turbo mixer for high speed dispersion of solids in grease (three times the processing speed of an ordinary mixer) and for gelling oils/fluids with thickeners such as silica. The advantage of the high speed dispersion is that more batches can be made in one day allowing greater capacity or smaller/fewer vessels.