Vietnam successfully fabricated multi-purpose dehumidifier and drying machine

Scientists at the Institute of Heat and Cold Science and Technology (Hanoi University of Technology) have successfully fabricated a dehumidified and heat-pumped type combined heat pump. This is the first time this machine has been successfully built in the country, very useful in preserving agricultural products.

Agricultural products after harvest need to be preserved Vietnam is located in the area of ​​hot and humid tropical climate with a coastline of more than 3,000 km, normal air humidity above 70%, the highest temperature can reach more than 38 ^o C. Hot and humid climate is a favorable condition for harmful molds and microorganisms to arise and develop, damaging many food, foodstuffs, medicines, plant varieties .

That fact became more and more frustrating for an agricultural country, the science and technology level is backward as our country. Many localities do not have equipment to preserve fruits, agricultural products after harvest, products must be dumped, sold at harvest time can only reach 20% value, compared to its real value.

In order to dry the product, the traditional method usually uses hot air (temperature from 60 ^° C to 120 ^° C), while to reduce the relative humidity of the air, people often use dehumidifiers to work according to principle of heat pump.

In the treated space, moisture reduction by a dehumidifier so that the temperature must always be higher than the ambient temperature, the relative humidity is not lower than 55%, in all outdoor air condition is often humidity 80% - 90%.

So far, for dehumidifying and drying, people often use foreign machinery and equipment. They are not only expensive but the parameters often do not guarantee in the days of high humidity, the yield and quality of products decrease. There have been cases where the installation of imported machines still requires the use of new domestic dehumidifiers to ensure stable and stable production. This is not to mention expensive imported equipment, high energy consumption, but only working for a short time in the hot and humid climate conditions have no longer achieved the specifications required by the technology.

After many years of research, the collective of scientists of the Department of Refrigeration and Air-Conditioning Engineering, the Institute of Heat and Refrigeration Science and Technology at Hanoi University of Science and Technology, was led by Assoc. Pham Van Tuy presided over, successfully designed and fabricated desiccant heat pump and cold-drying assembly type, within the framework of Ministry-level scientific research topic: " Research on dehumidification and cold drying of vegetables and fruits ".

The authors have proposed new technology solutions: For dehumidification and drying products do not need to use two types of equipment such as the traditional method, but only need to use air conditioning to dehumidify and dry at low temperatures. . This is the first time the dehumidifier and freeze dryer of agricultural products, foodstuffs and pharmaceuticals are designed and manufactured domestically, at reasonable prices, with high economic and scientific and technological efficiency.

In terms of economic efficiency, multi-purpose cold dehumidifiers and dryers also have many advantages: Save investment capital. Cost is only 50% of the price of imported equipment of the same type. 60 kW cold system, 20 ^o C - 27 ^o C mode, 35% - 45% humidity, 300 million VND. Cold 35kW system (120,000 BTU / h), 250 million VND.

From the solution of replacing air-conditioner + dehumidifier with air-conditioner combination, air conditioner is converted into heat pump, thus reducing energy consumption, for example, from 17.5 kW (old system) to 11.4 kW . After many years of work, the device still operates safely and effectively, suitable for hot and humid climate in Vietnam.

The project is facing the prospect of wide application and development in the field of preserving agricultural products, vegetables, medicinal plants . after harvesting or dehumidifying production environment for export goods, replacing goods. imported for post-harvest technology in Vietnam.

The project has completed 6 technology transfer contracts and research cooperation with research institutions: Hai Ha Confectionery Company Hanoi, Viet Tri Food Factory, Food Technology Institute, Hanoi Food Center. .

The topic was awarded " Patent patent ", Vietnam Science and Technology Innovation Award (VI FOTEC) in 2003, Associate Professor Pham Van Tuy was awarded " By creative labor ".

Not only that, the scientific staff of the research has studied in depth to improve the economic indicators - technical, compactness of the device and the ability to adapt to different types of products.

As one of the seven projects of the school upgraded to the project " Incubating technology " in 2005, the project has designed, manufactured and successfully applied the universal dehumidifier and dehumidifier for pump type. Low temperature thermostat branded HCMUT BK-BSH 18 is installed at Viet Tri Food Factory.