Industrial Food Drying Ovens – Gas Catalytic Infrared v. Convection Technology
If a new or replacement industrial food drying ovens are being considered, then a close look at the available technologies is advised. The two most popular available are Gas Catalytic Infrared ovens and conventional convection ovens. There are significant differences that relate to speed, suitability and cost. One of the key advantages of Gas Catalytic Infrared energy is that when applied to organic substances such as water , it is readily absorbed. This means that it is the water that is heated up and thus evaporates very quickly. This is achieved with very low levels of air movement across the food being dried. The added advantage is that the greater the moisture content, the greater the proportion of infrared that is absorbed. This means that the whole drying process can much quicker.
The best method of applying the infrared heat is to pass the food to be dried on a flat bed conveyor system with some form of tumbling or vibrating bed to rotate the food , with the gas catalytic infrared panels placed in a shallow inverted ‘V’, above the conveyor. The length of the oven is determined by the required conveyor line speed, which in turn is determined by the required production output.
Added Control with a Gas Catalytic Infrared Oven
Because catalytic heaters can be arranged into zones, that allow precision control using a PLC system, one can have infinite control over the heat output of each zone, from 20% to full output. Heat profile recipes can be created and stored within the PLC control memory. In practice, this means that different recipes can be called up, to suit either different food substances to be dried, or, similar foods that have different moisture content from batch to batch.
What About Operating Costs?
In general Gas Catalytic Infrared, because it is much more efficient at converting the available energy in the gas to usable heat energy, is much less expensive to operate. Achieving the desired moisture content can take up to 80% less time than in a convection oven. Given that infrared ovens are inherently more efficient, then considerable savings can be expected. If the oven is a replacement for an electric oven then given the fact that Electrical Energy is around four times as expensive as gas, then the savings become even more impressive.
Types of Food That Can Be Dried With a Gas Catalytic Industrial Food Drying Oven
Heraeus Vulcan’s gas catalytic infrared technology can safely be used on a wide range of foods and ingredients including grains, pulses and vegetables. Due to the nature of gas catalytic reaction, there are no noxious gases produced to taint the food as only water and carbon dioxide is produced. Operators also report that yields and the quality of the dried foods are improved due to the highly consistent application of heat and the level of control available.
Finally, What about Bugs?
As insects, larvae and eggs have a high water content, they are heated up and killed off very quickly once they reach 60°C. This happens very quickly in the drying process, and means that pesticide use can be reduced or eliminated.