Many products in confectionery industry are coated with sugar or a sugar
substitute.

The coating is applied in a water-based suspension, this is sprayed over the
centres in a rotating pan. Air is then blown on or through the product in order
to evaporate the moisture. This process is repeated many times over to obtain
the final percentage of coating required. Many of these centres are thermally
sensitive so a high air temperature is not desirable.

Within the coating process most of the time is used to dry the product in
sequential cycles. The drying time can amount up to 90% of the total coating
time.

The attention has to be focused on getting a constant flow of dry air in order to
maximize production capacity.
This has to be achieved with a uniform process drying time throughout the year.
This drying time is not affected by seasonal variations. The optimum system for this application is one that produces dry air via sorption dehumidification combined with refrigeration and heating.

Ambient air is filtered and pre-cooled, reducing it’s moisture content to the Sorption Dehumidifier. This cooling is essential during the summer season as it enables the system to reach the low dew points required.

After dehumidification the air is cooled or re-heated to obtain the required temperature for the process.

This combined air handling system has the following advantages:

• Clean filtered air.
• Ambient air is used affording an energy saving from the factories air conditioning plant and equipment.
• There are no seasonal variations because the conditioned air is constant throughout the year, therefore the production process time is predictable.
• The total process time is reduced by up to 35%. The very low moisture level of the air allows for a rise in production capacity and affords a better quality product.
• Pay back time of the initial investment is no more than 10 to 12 months.