Views:2 Author:Site Editor Publish Time: 2020-11-23 Origin:Site
Is the Fruit and Vegetable Drying Machine practical?
Since the beginning of this century, my country's timber supply has undergone major structural changes, which are shown as follows: first, the proportion of timber that has grown rapidly in industry has gradually increased; second, the proportion of imported timber has risen rapidly. On the other hand, as a large amount of energy consumption in the wood processing industry, wood drying accounts for 40-70% of the energy consumption of wood processing, and the thermal efficiency of drying is usually low, usually only between 30-40%. In addition, the pollution caused by the drying process is usually an important source of environmental pollution in my country. Taking a steam drying workshop with an annual drying capacity of 10,000 cubic meters as an example, the hazardous substances emitted per hour are about 40 kg of soot, 1900 cubic meters of carbon dioxide and 45 cubic meters of sulfur dioxide. There are also a small amount of nitrogen oxides in cubic meters, which are the main factors that cause atmospheric greenhouse effect, acid rain and ozone destruction. As the contribution rate of energy to environmental protection can reach 70-80%, the energy saving and environmental protection issues of drying technology are particularly important.
Fruit and Vegetable Drying Machine is suitable for drying all kinds of wood. It is an ideal substitute product for small and medium-sized furniture factories, wood products factories and old drying equipment. At the same time, it also has the advantages of easy operation, safe and reliable, low operating cost and saving investment.
The Fruit and Vegetable Drying Machine consists of a blower, a chimney, a return air duct, an air inlet duct, the main body of the hot-blast steam oven, a steam generator, a dehumidification system, a dry and wet bulb electronic display and an electric control box. The outer shell is welded by section steel and imported color steel, and the inner wall is made of high temperature anticorrosive aluminum plate. The metal shell dryer is not only beautiful in appearance, but also practical.
The internal and external panels of the Fruit and Vegetable Drying Machine are filled with new thermal insulation materials. The interior is composed of an evaporator fan, a furnace air duct, a dehumidification device and a control box. The hot air vapor of the drying box is completely isolated from the combustion chamber, the dried material will not be deformed, and the moisture of the wood will always remain unchanged.
There are two main types of water in Fruit and Vegetable Drying Machine: free water and absorbed water. The water existing in the large capillary system composed of cell cavities is called free water, and its increase or decrease will only affect the weight of the wood, but not the performance of the wood. The water present in the microcapillary system composed of cell walls is called adsorbed water. Changes in wood will not only cause wood shrinkage and expansion, but also affect other physical and mechanical properties of wood.
Wood drying is to remove free water and absorb water in the wood to adapt to different uses and quality requirements. Although there are many ways to dry wood, the basic principle is the same, that is, the use of the moisture content gradient along the thickness of the wood and the larger internal and small external water vapor partial pressure difference formed after heating to promote the drying of the wood . Moisture becomes liquid, and these two vapor states continuously move from the inside to the outside, and evaporate to the outside through the surface of the wood. The internal water movement intensity should be consistent with the surface water evaporation intensity, so that the wood is evenly dried from the surface to the inside.