T r i t h e r m
SPECIALIST IN HEATING & DRYING SINCE 1995
CONVENTIONAL DRYERS
Conventional heat and vent dryers are the most common type of dryers used for drying timber, agricultural products such as tobacco and mango, mosquito coils, seafood and many others. The heating medium in the form of Hot Water, Thermal Oil or Steam is passed into heat exchangers to heat up the circulated air travelling at high velocity to carry the moisture away from the product being dried. The moisture laden air is then vented out through air vents or dampers in exchange for drier fresh air. The fresh air entering the dryer is then heated up to lower humidity levels to increase it’s moisture absorption properties.
For a small drying set up, it will not be economical to build a steam boiler or thermal oil heater plant where many ancillary equipment are required. A simple biomass fired indirect hot air generator can be easily attached to a dryer and heat up the chamber effectively without having to provide pipings. Small biomass fired hot water heaters with automatic fuel feeded are also commonly used for small capacity dryers.
The choice of using the different heating medium depends on the product being dried
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There are five important factors critical to uniform and efficient drying : 1.) High air flow, 2.) Uniformity of distributed air flow,
3.) Sufficiency of heat , 4.) The way the materials are stacked to allow optimum and uniform air flow , and 5.) Effective venting or moisture removal.
SECTIONAL VIEW OF A STEAM HEATED CONVENTIONAL TIMBER DRYER
1. HEAT EXCHANGER 2. AIR-
7. SPRAY VALVE 8. SPRAY NOZZLE 9. SUB-
12. DOOR TROLLEY 13. TEMPERATURE AND HUMIDITY CONTROLLER WITH MOISTURE MEASUREMENT PROBES
Timber Fruits Paper Pulp Porducts Mosquto Coils Seafood
SOME OF PRODUCTS THAT CAN BE DRIED USING CONVENTIONAL DRYERS
For the drying fruits (such as mango and pineapple) and seafood , the circulation
air can be acidic, salty and corrosive. The materials used inside the chamber should
be non-
