Address: Kiev
We are selling or leasing timber drying plant with the capacity 215 cubic meters Modern European Equipment Production area 0,15 Hectares
Administrative office: 60 square metres
All communications
Sale / Leasing Price: $ 700.000
Leasing: $ 5.000 a month
Contact person: Anatoliy Artemchuk
Tel.: +38-067-382-28-09
E-mail: artemchuk
bigmir.net , artemchuk_z
ukr.net
Wood drying system brief
Wood drying is the basis of wood products, which is also one of the most important steps in wood processing. The quality of wood drying can affect the turnoff rate of the wood as well as the processing quality of the wood products. Thus, wood drying is a key step in using wood resources fully. At the same time, wood drying is the fundamental indemnification.
Since 1960's, the study of wood drying technology has gained quite great progress. Conventional steam drying technology taking the advantage of maturity in technology and fitness in large-sized production stands out at home and abroad. Dehumidification drying in low-temperature environment, hot wind drying, wave drying, vacuum drying and other drying technologies are put into effect to some extent.
In the process of wood drying, measurements over the drying environment factors and state factors are the core in realizing ideal drying technological benchmark. Because of various reasons, at present, measurement and control system in domestic wood drying are not very satisfactory. In most cases, semi-automatic wood drying measurement-control system is applied. Though full-automatic measurement-control system has been developed for many times, it is not popularized due to many reasons. Foreign wood drying equipment can been seen in Chinese market in some areas. The measurement-control systems of these imported equipment are generally semi-automatic or commonly seen full-automatic. Since foreign measurement-control outfits does suit the Chinese reality of high voltage wave, frequent power failure and other situations, many foreign outfits become paralyzed or semi-paralyzed.
Vacuum wood driers
Wood drying is essential and possibly the most complicated process in wood working technology. While working pine-trees, firs, larches, birches it is important to avoid inflicting a damage on source material in drying.
The FSUE “PA “Electrochemical Plant” has been manufacturing the equipment to provide fast and very cautious drying of raw lumber of various thickness. The first model manufactured by the PA ECP was the vacuum drier VS-1 which is now widely used by woodworking and joiner’s factories in Russia and the CIS.
The units are intended for wood drying in a vacuum chamber with circulation of drying agent at cyclic heating and vacuum removal of wet air.
The technology of vacuum wood drying ensures:
high quality of dried lumber (no cracks, warping, skewness, internal stress);
optimal drying time.
Normally initial wood moisture is 70-80%. To manufacture furniture and other wood products lumber with 6-8% moisture content is required. Traditional convection driers allow this moisture level for 250 hours, whereas drying in a vacuum chamber is 5-10 times faster depending on initial wood moisture, wood species and thickness. Power consumption depends on wood species, initial and necessary final moisture content.
The drier is ideally suited for both small-scale furniture and joinery productions and medium-size woodworking enterprises owing to its reliability, simple operation and economy.
Vacuum wood impregnator
The used vacuum technologies allow you to obtain unique results not only in wood drying but in wood impregnation as well. Such wood is widely used in agriculture, engineering and building industries.
So, one more line at the FSUE "PA "ECP" is manufacture of vacuum wood impregnators VAP-1 which are intended for impregnation of wood products with water soluble preservatives, antipyretics and dyes under the following scheme – vacuum-atmospheric pressure-vacuum. With all this going on they ensure 5 mm depth of impregnation throughout sound sapwood, and 10 mm depth of impregnation when using organic soluble solutions.
The impregnation process is run in the following sequence.
Impregnating agent is fed into the impregnation autoclave under the pressure of 0.085MPa after lumber has been loaded there.
Then the pressure in the impregnation autoclave is built up. While the pressure in the autoclave rises, the lumber "sponges up" preservatives, antipyretics and other impregnating agents.
The lumber is kept in the solution for 30-60 minutes, then the solution is pumped out, and the autoclave is evacuated.
The total time of the cycle equals to 1 hour 20 minutes.
Wood drying refers to reducing the moisture content of wood prior to its use. It is the process of removing its moisture contents to an average equilibrium with the atmospheric conditions of the locality of use. Ideally, wood is dried to that equilibrium moisture content as will later (in service) be attained by the wood so that further dimensional change will be kept to a minimum. Wood drying has lots of benefits but this is not common practices in developing countries like Nepal, India, Bangladesh and others. Only around 6-7 percent of the total production of industrial wood produced in India is seasoned in a strict sense (Pandey et all 1992) and in Nepal, it is estimated far less than India. This example shows the meager condition of wood drying.
Water in the wood:
Wood-water relationships:
The timber of living trees and freshly felled logs contains a large amount of water, which often constitutes more weight than the actual wood. Wood continually exchanges moisture (water) with its surroundings, although the rate of exchange is strongly affected by the degree wood is sealed.Water presents in wood in two forms:
Free water: The bulk of water contained in the cell lumina is only held by capillary forces: it is not bound chemically and is termed free water. Free water may contain chemicals, altering the drying characteristics.
Bound or hygroscopic water: Bound water is bound to the wood via hydrogen bond and it is found on the cell walls of wood.
Fibre saturation point:The point at which free water has been removed from the fibre cavities and they just begin to release their bound water is known as the “Fibre saturation point” In most woods, the fibre saturation point is at 25 to 30% moisture content. Many important properties of wood show a considerable change as the wood is dried below the fibre saturation point. These include: shrinkage resistance, increase in strength properties and electrical resistivity.
Equilibrium Moisture Content (EMC):The amount of moisture that remains in the wood at this stage is in equilibrium with the water vapour pressure in the ambient space, and is termed the equilibrium moisture content or EMCWood retains its hygroscopic characteristics after it is put into use. It is then subjected to fluctuating humidity, the dominant factor in determining its EMC. These fluctuations may be more or less cyclical, such as diurnal changes or annual seasonal changes. In order to minimize the changes in wood moisture content or the movement of wooden objects in service, wood is usually dried to a moisture content that is close to the average EMC conditions to which it will be exposed. These conditions vary for interior uses compared with exterior uses in a given geographic location. The primary reason for drying wood to a moisture content equivalent to its mean EMC under use conditions is to minimize the dimensional changes (or movement) in the final product.
References: www giec ac cn www ecp kts ru www forestrynepal org
