Greenhouse gas convection helps drying, drying agricultural products all night and day

Greenhouse drying, drying effect in two different convection regimes: Natural convection during the day and forced convection at night or rainy days, without sunshine.

The technique of drying / drying agricultural products by convection gas plants is to apply solar energy to dry objects directly with convection gas flow. This technique is suitable for instant vegetables after drying / drying.

According to MSc. Le Thanh Tung, Santavi Agricultural Machinery Joint Stock Company (Hai Tan), currently drying / drying agricultural products, cereal grains, fruits, vegetables, spices . by using greenhouse drying / drying techniques. Many experts rated it well, because the product quality after drying was high compared to traditional drying and drying methods.

Old bananas can also be dried and dried indoors.

The first important thing when building the drying system, drying agricultural products by convection gas greenhouse is to select the land to arrange drying and drying houses . It is a place to "welcome the sun", not being covered by trees, houses or other architectural objects from light from the sun, with fresh wind, far from polluted air sources (pig stables, brick kilns, lime kilns . )

Drying and drying structures are usually shaped with a dome-shaped frame or stainless steel parabolic tube, buried or placed on a concrete floor (with or without ceramic tiles, ensuring cleanliness and anti-slip). The area, length and width of the drying / drying house depends on the output of agricultural products that need to be dried / dried and the productivity / batch, calculated according to natural drying technology or with supporting equipment.

Hand blows, door frames and main doors are attached to the frame by specialized belts and screws, not rust and durable. Roof surface, two gables for drying and drying are covered with polycarbonate heat collecting sheet. Plastic sheets used exclusively for drying and drying agricultural products have the effect of collecting heat from the sun and keeping the heat inside the house drying and drying.

Warranty of polycarbonate sheet is 10 years, in fact can be used for over 12 years. Except for the main door and inlet and outlet ventilation (depending on the design), there is a protection net to avoid dust and insects entering the drying / drying house, the whole house being exposed to drying / drying to isolate the environment is necessary. set to ensure hygiene and food safety.

Raw materials to be dried / dried are placed on stainless steel grating at the height of the abdomen - suitable for posture of arranging workers, reversing or collecting products after drying. With this drying / drying rig, conventional airflows on both sides of the drying material help the agricultural product dry out, dry quickly from both sides, reduce the reversal.

Banana drying process at Unifarm.(Photo: T. Tung).

When the sun shines, a heated drying / drying house heats the drying chamber and creates a hot air flow that carries steam from the inside out. At a certain time, the moisture in the agricultural product decreases gradually to the level of dryness required to be preserved.

The drying / drying house will operate in the sun and will gradually decrease and then stop when the heat is no longer available. For drying / drying operation both day and night, improving productivity 5-8 times compared with drying / drying with greenhouse effect only waiting for sunlight, it is necessary to install by installing the system Moisture separation and heat supply support. In terms of technology, greenhouse drying houses operate in two different modes of natural dry convection during the day and forced convection at night or rainy days, without sunshine.

MSc. Le Thanh Tung added that, in order to promote the drying / drying function, every month or when there is a dusting phenomenon, it is necessary to clean the system by washing with glass cleaning water and clean water of the entire roof and domed walls. , both inside and outside. In addition, it is necessary to clean all floors, blisters and all details in the drying house.