There are many sawmill or a furniture business that have some difficulty in choosing the right wood dry kilns for their needs. As there are many different ways of kiln wood for sale on the market, it is particularly important for sawmills and furniture companies to choose the right wood dry kiln for drying high grade lumber.
Today’s article takes a look at one of the more advanced dryer kilns available today – the vacuum kiln dryer!
In contrast to modern wood drying use kiln, When wood is dried in a vacuum kiln, a vacuum pump is used to suck out the air. The whole drying process is carried out under vacuum.It is well known that the vacuum lowers the boiling point of water. When the vacuum dry kiln is at -0.07 to -0.08 Mpa, water molecules start to vaporise at 40-50°C.
Therefore, the wood is dried in a low temperature and oxygen free environment, which can accelerate the drying time faster and maintain the original color of the wood. On the other hand, regular kiln use heat and air circulation to slowly dry the wood, which takes a long time to dry and requires careful handling by the workers, otherwise the quality of the wood will deteriorate.
There are many vacuum drying wood systems on the market. But not all systems are created equal, so what are the advantages of high-frequency vacuum lumber dries kiln systems?
The Working Principle Of High-Frequency Vacuum Kiln.
High frequency vacuum dry wood is a combined drying method of high-frequency medium heating and vacuum low-temperature drying. It is a faster drying method with low waste rate, especially suitable for the drying of hardwood and slabs heavy wood.
A high-frequency electric field is used as the heating source. The electric field radiates evenly on the wood merchant and penetrates the wood to directly heat the moisture, while the vacuum’s absorption effect accelerates the moisture evaporates.
The wood itself or other non-polar materials do not receive high frequency electric field, the electric field will penetrate the wood, the drying process is only the friction between the water molecules themselves to generate heat, so the high frequency energy is uniformly concentrated on the moisture in the wood, and the more local moisture, the more the electric field distribution.
Vacuum State.
The boiling point in the vacuum state is low, and the water in the high frequency dryer equipment is heated to 60 degrees Celsius nine starts to vaporise, achieving the purpose of drying in a lower temperature state, greatly reducing the problem of wood cracking and deformation, especially suitable for drying more valuable wood that is sensitive to temperature. And the effect of negative vacuum pressure absorption accelerates the dry process even more.
High-Frequency Vacuum Dryer Equipment With Hydraulic Device On Top
There is a stainless steel hydraulic cylinder in the drying oven, which can apply 6 tons of pressure to the wood. By drying with this pressure, the wood can be kept flat without bending. There is no warping or cracking of the timber.
Features Of The High-Frequency Vacuum Dryer Kilns.
Humanised control interface, touch screen console, more scientific and rational design ideas. Automatic drainage, automatic heating, opening or closing the high frequency and vacuum system, easy to use. Humidity control system, traditional humidity detection loses its effect under high frequency electric field, can detect drying process more accurately.
Cooling Tower System.
Steam from the wood drying process is cooled and condensed into water and then flows into the water storage tank, the gas temperature is reduced and then pumped out by the vacuum pump.
Timber Cart.
Feeding and discharging, the wood can be put into the vacuum kiln more conveniently, saving labor.
Features And Advantages Of High-Frequency Dryer.
In high frequency dryer equipment, wood is in the middle of high frequency pole plate, the electric field directly penetrates the wood as a whole and heats evenly, while the vacuum’s water absorption accelerates the water to take effect, the lumber itself does not absorb the electric field, so the water is quickly heated and vaporised,
Due to the internal temperature and water vapour pressure, a pressure gradient is formed inside the lumber,forcing the core moisture contents of the wood to be discharged to the surface and the water vapour to be discharged into the tank, so high frequency drying is from inside to outside Heating;
Which is just the opposite of traditional steam or heating with air so that the relative humidity on the surface of the wood is high, eliminating the need for constant spraying of water during the drying process, while heating is more uniform, fast and less prone to cracking and warping.
Therefore, The Advantages Of A High-Frequency Vacuum Drying Kiln Are As Follows
1. Fast Heating;Uniform Heating:
No problems with both green wood and thicker timber
Fast drying period and increased efficiency -HF vacuum kilns can dry products much faster than conventional vacuum kilns. For example, it takes only 7 days to dry a thick 8 cm rosewood from 50% to 10%
This means you can get your products to market faster and increase your competitive edge.
Where there is more moisture, the stronger the electric field, the overall moisture content of the lumber is consistent after drying, making solid wood products more stable and less likely to deform
2. High Drying Quality
Improved product quality – with a high frequency vacuum kiln drying system, you get better product quality due to even heat distribution and short drying times.
3. Small Floor Space And High Lumber Load Capacity
Space saving – with a small footprint of a HF vacuum kiln drying plant, you can place it in a small space, which helps you save on the cost of renting or buying a larger space. Take advantage of this to reduce your overall costs. The kilns also can load many lumber slabs.
4. Reduced Energy Consumption
High frequency vacuum kilns use less energy than traditional vacuum kilns. High frequency power utilisation is much higher than ordinary electric heating, reaching 60% or more, compared to 20-40% for ordinary electric or other heating methods, which will save you money in the long run.
5. Save Labour And Reduce Labour Intensity
Simple and easy to understand operation, one person can operate the equipment, manual automatic dual system, switch freely
6. Environmentally Friendly
The wood drying process has no impact on the environment and no harmful substances are emitted.
In addition, high-frequency vacuum kiln has the advantage of effectively killing adult insects and eggs in the lumber without the use of chemical-based chemicals.
The vacuum dryer kiln is currently the most advanced drying equipment for drying lumber, without the need to wait for a long time.
Many sawmills and furniture factories need to get their money flowing quickly and need to get their finished lumber dried quickly so they can make a benefits. They choose vacuum kilns to do the work for them.
High frequency vacuum dry kiln is the best choice to thick table top, veneer, thick slab, expensive wood, hardwood, veneer, beam and etc.
So now do you have a general understanding of vacuum kiln and make your choice according to the actual situation of your business, if you want to know more about vacuum kilns and any idea, feel free to contact us! We will give you more services.
