Rowan Foods install second Browning Machine using Heraeus and Protech's expertise.


Carbon infra-red (CIR) emitters from Heraeus Noblelight form an essential component of an industrial browning machine on a food production line at Rowan Foods Ltd of Wrexham. The custom-built machine is used to brown potato and pasta toppings and follows on from the successful installation of a similar system seven years ago.
Rowan Foods manufactures a range of potato- and pasta-based ready meals for major high street supermarkets. For final presentation, it is important that the product toppings are pre-browned. Surface browning must be carried out without any after-cooking of the product itself and, historically, has been carried out by means of steam- or hot air ovens or by long-wave radiant heaters and electric panel heaters. However, all these technologies have a large footprint and tend to have a cooking effect on the product, while gas infra-red systems can introduce unwanted volatiles into the cooking environment. Moreover, they can be difficult to maintain and are not very energy-efficient.


When the company decided to install a new production line to meet increasing demand for its product, they had no hesitation in contacting food processing machinery specialists Protech Food Systems of Bedford who had built and installed the first line in 2006. Protech then worked with Heraeus to design and build a new browning oven, incorporating the latest carbon infra-red technology. Carbon infra-red is ideal for applications in the food industry, such as surface browning. It delivers medium wave infra-red radiation, which is perfectly suited to evaporating water from products, at a very high power density. This ensures that the surface of the food product rapidly achieves a sufficient temperature to drive away any local moisture and then cause browning without any possibility of after-cooking. This also allows any subsequent chilling operation to be carried out as efficiently as possible.

The new browning oven features two separate heater modules, for production flexibility. One module is fitted with eight 4kW emitters and the other with an additional six 0.5kW emitters, which are separately controlled to supplement the heating energy at the edges of the oven. Emitter failure detection is provided to ensure that, in the unlikely event of any emitter in either cassette being broken, this will be detected and an alarm raised.

Since installation, the new system has proved to be as reliable as the first oven, requiring little or no maintenance. Moreover, it allows significant energy savings compared with competitive systems due to the fact that the carbon infra-red system switches on and off virtually instantaneously, eliminating the need for lengthy pre-heating of the system to the required operating temperature at the start of each shift. The fast response of the system also means that the heat can be removed very quickly if the line stops unexpectedly, so minimising damage to product.

Heraeus specialises in the production and application of high quality energy sources covering the electro-magnetic spectrum from ultraviolet to infra-red. It has over 40 years experience in infra-red technology and offers the expertise, products and systems to provide efficient and effective solutions to drying, heating and curing problems throughout industry.