EKOTEC HEAT PUMP DRYER METHOD AND ITS DIFFERENCE FROM THE OTHER DRYER METHODS (1)
EKOTEC Heat pump dryers recover the latent and sensible heat from the exhaust gas by condensing moisture from the drying air. This way it increases the energy efficiency by heating the dehumidified drying air with the recycled recovered heat. With other conventional drying methods, this heat recovery would be lost in the atmosphere. This enables drying at lower temperatures, lower cost, and operation even under humid ambient conditions.
With EKOTEC heat pump drying, there is control of the moisture and temperature of the air as well as heat recovery. In this way, a heat pump dryer can improve the product quality while using less energy and with less drying time. Any dryer that uses convection as the primary mode of heat input can be fitted with a suitably designed heat pump.
Heat pump drying technology has been combined with other drying techniques to achieve improved product quality, reduced energy consumption, high coefficient of performance (COP), and high thermal efficiency.
Heat pump drying consumes only about half or one-third of the electricity of conventional condenser dryers. HPD had the lowest operating cost when compared to electrically heated convective dryers.
OTHER DRYER METHODS
Sun and solar drying :
Sun drying refers to foods that are dried under the direct sun. Sun drying is the oldfashioned way to dry food because it uses direct solar radiation and the natural movement of the air, ambient air temperature, and relative humidity. This process is slow and requires continuous care, the food must be protected from insects, covered at night and it cannot be used in rainy periods. Thus, it is a long-drying process, the quality of the final product is low since the conditions and parameters of the process cannot be controlled. However, is the cheapest drying method and does not have special needs of equipment or energy consumption costs, so it is suitable for developing countries with proper weather for the process. The drying time depends on product characteristics and drying conditions but it typically ranges from 3 to 4 days.
Vacuum dryer :
Vaccum-drying technologies are used to intensify moisture removal when lower drying temperature is needed to protect heat-sensitive food components. Vacuum drying is similar to freeze-drying, which will be later developed, but in vacuum drying the product is not frozen and the vacuum is not as high as in freeze-drying. Heat transfer occurs in this process by radiation and conduction. The vacuum dryer system consists of a vacuum chamber where the product is placed, a heat supply, a device for producing and maintaining the vacuum, and components to collect water vapor evaporated from the food. The vacuum drying technique is rarely used to dry fish.
COMPARISON Of FOOD, FRUITS, and VEGETABLES DRYING METHODS
|ITEM||Direct/indirect sunlight||Wood burning||Electrical heating||Diesel engine heating||EKOTEC Heat pump dryers
|Temperature range (°C)||≤40||10-100||0-100||10-100||10-65|
|Operation time||During the day||Any time||Any time||Any time||Any time|
|Drying airflow||Depends on wind||N/A||Controlled by the fan speed||N/A||Controlled by the fan speed|
|Moisture extraction||Depends on weather||Low||Accurate||Low||Accurate|
|Temperature control||N/A *||Fair||Accurate||OK||Accurate|
|Product quality||Depends on weather||Bad, Because of Smoke||Good||Bad, Because of Smoke||Very good|
|Environmentally friendly||Yes||No||Yes||No, because of CO2 emissions||Yes|
|Weather effect||Yes||No, if the operation is indoors||No, if the operation is
|No, if the operation is indoors||No, if the operation is indoors|
|Initial capital cost||Low||High||High||High||Very high|
|Maintenance costs||Very low||Low||High||High||High|
* N/A, not applicable