Air Conditioning Systems and Hot Air Generators

SEI Contreras Engineering has provided equipments and turn-key plants for the food and chemical industries for over 40 years, focused on the evaporation and drying processes.

An indispensable and essential component needed to obtain a high quality product is the air involved in the drying process. Besides this, the plant's production capacity and thermal efficiency is deeply affected when the drying air is not correctly conditioned. This is why the adequate design, sizing and selection of the hot air generator is not a lesser detail.

SEI Contreras Engineering provides air condition systems and hot air generators for spray, flash and fluid bed dryers, as well as any other installation that needs air with specific requirements regarding temperature, flow rate, pressure and humidity.

Both heating and dehumidification of the air determine the size and performance of the drying equipments. Inlet humidity should be as low as possible to increase drying capacity without risking having condensation inside the outlet ducts. In order to achieve this it is necessary to filter the air and extract water from the ambient air to adequate levels for each process.

Also, air temperature is critical to determine the size and type of drying equipment, given that at a higher temperature a lower air flow rate is required. Nevertheless, it is important to have knowledge of each product and process in particular, because if contacted with high temperature air, some sensitive products will present a lower quality or even generate unwanted by-products due to decomposition.

Depending on the product, hot air generators should be direct or indirect type, if combustion gasses are mixer with drying air or not. For most food and chemical applications direct type generators are used, but for others this is not allowed or it is tradition to use the indirect type.

This type of hot air generators have a tube bundle in them, inside of which the heated air flows. The tube bundle is placed inside the combustion chamber and the exterior walls of the tubes are in heated, thus heating the air inside them. In this type of equipment is necessary to be careful where to located the tube bundle, in order to avoid excessive heating of the tubes.

Hot air generators are needed for almost every type of drying process with the exception of ambient drying and steam heated dryers, giving them a wide variety of equipments and applicable processes.