Humid weather conditions in summer - or any time of the year - can wreak havoc on confectionery manufacturing operations. Packaging equipment clogs, chocolates blush, pan coatings “pick,” candy sticks together and even breaks apart, and production, transport and storage are impeded.
High humidity environments can reduce profits, interrupt operations and create severe quality problems. The use of desiccant dehumidification to insulate manufacturing operations from the effects of high humidity is an effective method to avoid these sticky situations and achieve confection perfection.
Conventional Humidity Control UnreliableSome confectionery operations rely on conventional, refrigeration-based air conditioning systems to control humidity. Such systems have advantages, including a low installation cost and favorable operating economics, and are especially effective when the humidity level needs to be high such as in fruit and vegetable storage.
However, it can be difficult for a refrigeration-based system to produce the low humidity levels needed during some confectionery processes such as during pan coating, or to prevent re-absorption of moisture.
To achieve low relative humidity levels, a refrigeration system must first cool the air, removing moisture by condensation. Because the air is essentially saturated - 100 percent relative humidity - when it leaves the cooling coil, it must be reheated to have a low relative humidity.
While this technology works effectively at high temperatures and moisture levels, it becomes very inefficient when it must produce the low humidity required for confectionery manufacturing. This means large, expensive and complex systems that are difficult to maintain and energy inefficient.
A refrigeration system also is limited in how dry it can make the air. As the coil attempts to cool the air below 32°F (0°C), the condensed moisture freezes and the coil must stop cooling in order to defrost.
In processes that require both low temperatures and low relative humidity, the refrigeration system may produce erratic results, particularly in the summer when both temperature and moisture levels are high.
Utilizing Dehumidification in Candy ProductionOne method to protect raw materials and products during production, storage and transport is utilization of desiccant dehumidification.
Desiccants are adsorbent or absorbent materials that remove water vapor from the surrounding air. This desiccant is impregnated into a corrugated fiberglass composite material that is formed into a wheel. This dehumidifying wheel acts like a sponge, adsorbing the moisture from the air. The moisture is released by the desiccant when heated in an exhaust airstream, avoiding the hazards of condensation altogether.
For example, by implementing dehumidification, the supply air introduced into the pan coating process can be maintained at 40°F and 20 percent relative humidity rather than the near 100 percent relative humidity with refrigerant-based units.
Because refrigerant-type systems rely on moisture to condense on the cooling coil, the air is close to saturation and needs to reheated in order to lower the relative humidity.
Panning is a key area where humidity must be continuously controlled. As a confectionary product is rotated in the pan, and a coating is added, there cannot be any caking or lumping, and the coating must be dried. Providing dry, clean air to the panning area results in more rapid, even evaporation of water from the candy. This ensures the correct hardness and shiny coating while not reducing production capacity.
Chocolates or any candies that require a shiny texture or coating typically are the most sensitive to humidity during production.