As a leading independent manufacturer of natural extracts, oils and flavours for the food industry, Lionel Hitchen has opted to standardise on pneumatic controls from Spirax Sarco to ensure that every batch of product reaches the required standard.
Lionel Hitchen was confident that Spirax Sarco controls could provide the reliability and precision required in some of its most crucial temperature control applications, since it has used a variety of Spirax Sarco products around the site for 15 years.
The chosen system controls the temperature on the company’s resin blending vessels, which are heated using steam jackets. It relies on a Spirax Sarco KE71 control valve, fitted with a PN6000 actuator and a PP5 pneumatic valve positioner. A temperature probe inside the vessel feeds data back to a PN600 pneumatic controller that oversees the process.
Pneumatic controls suitable for use in ATEX-zoned areas were the natural choice, since the atmosphere in some parts of the factory is potentially hazardous. “There’s no electrical signal so there’s no risk of ignition,” says Engineering Manager Chris Dimmick. “And the main thing is that the products are all very reliable.”
Many of the flavour ingredients made by Lionel Hitchen are very expensive. A typical herb extract might cost anywhere from £50 to £200 per kilogram for example, with some of the more exotic extracts costing many times more. The company blends and standardises batches of these extracts in vessels with a capacity of either 600 or 1200 litres.
Precise temperature control is essential throughout the process, explains Mr. Dimmick: “When we produce an oleoresin we need to standardise it by blending it with other ingredients and heating it to a specified temperature. Every product is different with a different viscosity, but we can’t burn it or we’ll spoil the flavour. Whatever the product, we have to be able to set the process at a particular temperature to suit.”
In addition to its resin blending vessels, Lionel Hitchen has also adopted the same Spirax Sarco equipment to control the cooling water flowing through some of its distillation plants, bringing the total number of temperature control systems currently in use on the site to ten.