Drying chambers. Drying chamber for lumber: how to do it yourself? Types and manufacture of drying chambers

Any woodworking enterprise cannot do without such a procedure as wood drying. And so that no defects appear in the process, a special drying chamber for lumber should be used. Such a dryer will also be useful for those who are engaged in the production of wood products at home, in such cases it can be done by yourself.

Importance of drying for wood

Wood for the manufacture of various products must first be dried so that it is suitable for subsequent use. So, if your furniture is made on the basis of too wet wood, then it will quickly dry out and become unusable. And if the tree is too dry, then, for example, the door will quickly swell and will not close.

Also, drying a tree is useful for the following reasons:

the material is protected from fungal attack;
change in size and shape is prevented;
improve the mechanical and physical properties of the material.

Drying is a lengthy process, the wood is heated with hot air or superheated steam. After drying, the tree can be stored and transported longer, it will not be deformed.

Drying chamber for lumber

Kiln drying is a key way to dry wood. With the help of dryers, deciduous and coniferous species are dried to different types of quality. The most common and economical drying technique is as follows. Free and bound moisture is removed from the wood by supplying heat to the damp wood using hot air. Further, the removal of excess evaporated moisture occurs with the help of humidified and partially cooled air.

The drying chamber is a completely finished installation, equipped with all the necessary equipment for work. By their design, such chambers are prefabricated metal or assembled from building materials. The latter are made directly in the workshops or as free-standing buildings based on industrial materials.

The chamber can be entirely made on the basis of monolithic reinforced concrete, the walls can be made of solid red bricks, and the ceiling can be made of reinforced concrete.

If several chambers are used during production, they can be combined into one block, which has a corridor with heat supply wiring and an automatic control system. Depending on the volume of loaded wood, the air circulation can be horizontal-transverse or vertical-transverse.

Lumber can be loaded into the chamber on trolleys along the rail track or as packages using a forklift. Heat is transferred to wood in the following ways:

through the air;
through the products of combustion;
using superheated steam;
radiant warmth;
solid body;
through current;
through an electromagnetic field.

The equipment for this device is basic and additional. The main includes the following:

fan system;
heating system;
humidification and supply and exhaust ventilation.

Additional equipment includes:

blocks (door, psychrometric and insulated);
fan drive electric motor;
stacked carts.

The drying control process can be automated, which helps to maintain the temperature and humidity inside the chamber at a certain level. The temperature is regulated by supplying the coolant to the heaters or by turning the electric heater on or off.

Humidity can be adjusted using a remote moisture meter, which allows you to check the condition of the material remotely at several points at once. If there are no external sources of heat supply, then autonomous heating means powered by electricity, coal, gas, lumber or diesel fuel can be used.

Structure classification

In convection-type chambers, energy enters the wood through the air cycle, and heat transfer occurs through convection. Such structures are tunnel or chamber.

Tunnel dryers have a greater depth, they push stacks of stacks from one end (wetter) to dry. They are obligatory filled from one end, and emptied from the other. Stacks are pushed one at a time every 4-12 hours. These dryers are used for large sawmills and help carry out transport drying.

Chamber dryers are shorter; during the drying process, the same parameters are maintained throughout the chamber. If the blowing depth is from 2 meters, then in order to equalize the drying conditions, the method of reversing the ventilation direction is used. The chamber is filled and emptied from one side if there is only one door. Lumber can be dried any to different indicators of humidity. It is these designs that are most often used in our country.

The condensation type of dryer is different in that the moisture that has arisen in the air begins to condense on special coolers, and then the liquid is removed. The efficiency here is high, but the cycle is long, since devices with a high temperature do not work and large heat losses are observed. These types of equipment are more suitable for processing small volumes of materials or drying wood of dense species - ash, beech or oak. But condensation chambers also have a number of advantages:

no need for a boiler room;
the cost of the camera and the cost of operation are low.

Drying chambers also differ in the way of circulation and the nature of the drying agent, the principle of operation and the type of fence.

For example, circulation can be natural or forced. The designs of the first type are outdated and inefficient, it is almost impossible to control the modes, and the uniformity of the drying of the material leaves much to be desired. With modern requirements, it is better not to use such dryers.

By the nature of the drying agent, the chambers are:

air;
gas;
high temperature.

Drying modes

Depending on the quality requirements, lumber drying in a special apparatus is carried out in different modes, which differ from each other in temperature. If it is a mini chamber, then in the process the temperature slowly rises and the relative humidity of the agent decreases.

One or another mode is selected taking into account the following factors:

There are modes of high-temperature and low-temperature process. In low-temperature applications, moist air is used as an agent, the initial temperature is less than 100 degrees. There are three categories of these types of modes:

soft - drying is carried out without defects, the mechanical and physical properties of the wood are preserved, including its color and strength;
normal - drying is also carried out without defects, strength is retained almost completely, color may vary slightly;
forced - the strength for static bending, tension and compression is maintained, but the strength for chipping and splitting with darkening may decrease.

In high temperature conditions there is a two-stage change in the agent's indicators, it is possible to switch to the second stage from the first only when the wood reaches a transitional moisture content of 20 percent.

Such modes are assigned depending on the species and thickness of the wood, and are assigned for drying materials used in the production of load-bearing structures of buildings and those products where dark wood with reduced strength can be used.

Before starting work on a particular mode, the lumber must be heated with steam supplied through humidifying pipes with fans running, closed exhaust ducts and heating devices.

Be sure to calculate the chamber for lumber. The temperature of the drying agent at the beginning of heating should be 5 degrees higher than the first stage of the mode, but not higher than 100 degrees. The saturation level of the environment for a material with an initial moisture content of 25% is 0.98−1, and if the humidity is below this indicator, then 0.9−0.92, respectively.

The duration of the initial period depends on the type of tree. For conifers, it is up to 1.5 hours per centimeter of thickness. For soft hardwoods it will be 25 percent more, and for hard hardwoods it will be half as much as softwoods.

After preheating, it is necessary to bring the indicators of the drying agent to the first stage of the operating mode. Then drying starts directly in compliance with the selected mode. Humidity and temperature can be controlled using valves on the steam lines or dampers on the supply and exhaust ducts.

During the operation of an infrared dryer, residual stresses appear in the materials, which can be removed by intermediate and final moisture and heat treatment in an environment of high humidity and temperature. It is necessary to process those lumber that is dried to operational performance and then needs to be machined.

Intermediate moisture heat treatment must be carried out during the transition from the second stage to the third, or from 1 to 2 when using a high temperature. Coniferous species 60 mm in thickness or hardwood with a thickness of 30 mm or more are subjected to such processing. The temperature of the medium should be 8 degrees higher compared to the second stage, but not more than 100 degrees, provided the saturation is 0.95-0.97.

When the final average moisture content of the material is reached, the final moisture heat treatment can be performed. It is carried out at a temperature of 8 degrees above the previous stage, but not higher than 100 degrees. Further, the tree must be kept in the chamber for another 2-3 hours at the parameters of the last stage of the mode and only then stop the operation.

Drying chamber manufacturing

If you are engaged in the manufacture of wood products at home, then you will need to dry the material yourself. You can also make your own dryer., but you must follow all the rules of work. For manufacturing you will need:

camera;
heating device;
fan;
insulation.

One wall and the ceiling of the chamber should be made of concrete, and the remaining walls will be made of wood, they will need to be insulated. There will be several layers:

Styrofoam;
boards wrapped in foil.

Now you need to install a heating element, it can be in the form of batteries. Water can be supplied to them from the stove in a heated form at a temperature of 60 to 95 degrees. It is best to ensure a continuous process circulation of water by means of water pumps in the heating element. You will also need to install a fan in the chamber, with the help of which warm air will be distributed throughout the room.

It is imperative to provide a method for loading wood into the chamber. For example, it can be a rail cart. To control the temperature and humidity in the work area, you need to install wet and dry thermometers. And also inside the dryer You need to put shelves to expand the workspace.

During processing, a sharp change in temperature should not be allowed, otherwise the wood may crack or warp.

Work on the construction of the chamber must be carried out in compliance with fire regulations, so be sure to install fire extinguishers.

And instead of a heating element you can use an electric stove with two burners. The walls of the chamber can be insulated with wood shavings, and instead of foil, you can take penofol, which can reflect heat well from the surface of the walls. Drying in such a chamber is carried out within 1-2 weeks.

Thus, there are a large number of different modifications of wood drying chambers. One or another option should be chosen depending on the material itself and the expected results. And if we are talking about the manufacture of various wooden products at home, then the camera is easy to do with your own hands.

Industrial processing of wood is possible only after its preliminary drying. Dry wood is protected from fungal attack, retains its size and shape, and has better physical and mechanical properties. This stage of lumber production is long and complicated, therefore, special drying chambers or, as they are called in a professional environment, “dryers” are used for its implementation. Currently, the range of equipment in this category is presented quite widely, which makes it easy to choose equipment for specific tasks. The main difference between the models is the method of evaporation of moisture: vacuum or convective.

Technical features of drying chambers

A significant advantage of modern devices is the possibility of using for drying both ordinary and exotic wood species that require a particularly careful attitude. These are such popular samples of raw materials as teak, wenge, rosewood, beech, anegri and others, from which high-quality lumber and boards are produced, and which are used in interior decoration and furniture production. In the process of processing, the blanks are not subjected to cracking and warping, fully retaining their external and practical advantages.

Advantages

The KAMI company carries out direct deliveries of industrial kilns for wood from the world's leading manufacturers. With the help of our specialists, you can easily select and buy the right equipment option for a small or large workshop, aimed at constantly increasing production volumes. Prices are kept at an affordable level, which will avoid additional costs and rationally equip production. And effective logistics from KAMI is a way to get your purchase as soon as possible, regardless of whether you are in Moscow or in another city in Russia.

The drying chamber is the most important equipment in woodworking enterprises, as it allows you to remove moisture from lumber, heat-treat wood to prevent biological destruction, give resistance to decay, maintain mechanical strength at the lowest density, create minimal thermal and electrical conductivity in wood.

What are drying chambers and complexes?

Drying kilns are industrial equipment used for drying various types of lumber and wood species, hardwood or softwood, for pallet fumigation. To process large volumes of wood, modular chambers are combined to create large-sized drying complexes.

Types of drying chambers and drying modes

MAKIL PLUS LLC offers drying kilns for lumber, with boilers (heating units) burning (utilizing) wood waste, which are divided into two types, depending on the heat carrier used:

Heat carrier - water . These installations consist of a boiler and water heaters, circulation pumps, automation adapted for use in cold weather (anti-freeze system), water treatment system. The system copes well with water softening, and the boiler power is selected based on the volume of drying chambers and additional consumers. Based on the above, a drying complex for drying water-type lumber has a large initial cost of the project, as it includes many expensive elements and requires specialized installation.
Heat carrier - air . The system includes a 100-500 kW air heater, a centrifugal fan and an air duct system. The initial cost of this equipment is included in the cost of the camera, the customer receives a turnkey solution without additional capital investment. The universal air heater has a higher efficiency than a water boiler and is capable of delivering both minimum and higher temperatures than a water-type wood dryer.

For processing wood in drying complexes, three main modes can be used: soft, medium and forced. While maintaining a soft mode with a temperature of up to 55 ° C, during the drying process, the wood retains all its properties, without changing its strength and color. When using the medium (normal) mode with temperatures up to 67-70°C, the shade of the wood changes slightly. For high temperatures up to 85-90°C in forced mode, fast drying is typical, but with darkening of the wood.

Technologies used by the company in the manufacture of cameras

The main advantage of drying chambers for the forest is:

Autonomous mode of operation of the system in the absence of heating networks
Minimum fuel costs with simultaneous disposal of waste
Compactness of placement of the main and auxiliary equipment
The possibility of dismantling the equipment and moving it to the prepared foundation
High degree of thermal insulation of the chamber as a whole, tightness and insulation of sliding gates
Fast heating up to the required temperature
Minimum heat loss through structures
Drying agent and heat carrier both air and water.
Possibility of fast re-equipment under the heat carrier.
Ease of maintenance, ease of management.
Possibility of drying at any modes.
Drying complexes are made of 80% of Russian materials that do not require a long wait for replacement.
The modular design allows new drying chambers to be added without stopping the existing chambers.
Thermally protected reversible axial fans with Siemens motors/
Litouch drying process control system from world leader Logika concern
The ability to program the controller up to 16 phases of lumber drying, which allows you to create special climatic conditions inside the chamber for the drying process.
High maintainability during operation

Data technologies not only allow to dry lumber without discoloration and cracking, but also ensure trouble-free operation of the equipment.

Economic payback of chambers on wood waste

Economic payback is one of the benefits of MAKIL PLUS equipment. The drying complex for wood, on average, pays off within a year, since the cost of drying 1 cubic meter, including the cost of servicing the device, is about 450 rubles. In addition, purchasing a plant that is completely ready for operation solves the problem of wood waste disposal. At the same time, mixed waste, even with a high percentage of moisture, is suitable for work.

The company "MAKIL PLUS" puts on sale drying equipment with chambers from 10 to 140 m 3 , which are manufactured both according to ready-made projects and according to individual customer requirements. MAKIL PLUS wood drying complexes are already operating in every region of Russia and are becoming more in demand every day.

More detailed information on this equipment and its purchase can be obtained by contacting the managers of our company.

Today, many technologies for high-quality drying of sawn timber and raw wood are known, and each of them has its own specific advantages, disadvantages and side effects. But still there are companies that use these technologies, offering their models of equipment for the implementation of complex heat treatment of various types of wood.

Manufacturers from various countries are engaged in the production of drying equipment, but everyone strives to make their technology better, more reliable and practical, shielding the positive aspects and hiding the negative ones.

When choosing a drying chamber for lumber, it is necessary to rely not on the manufacturer and trademark, but on the features of the equipment, drying technology and workmanship. Of course, all manufacturers promise high quality, provide compliance with all GOSTs and SNiP.

The main thing is that the equipment should allow achieving acceptable humidity parameters, which are 8-14%, have low energy consumption and quickly perform high-quality heat treatment. But the most important indicator is the percentage of marriage during the drying process.

The main countries manufacturers of drying chambers present on our market:

Russia
Italy
Belarus
Ukraine
China
Austria
Czech

These countries produce chambers of various technologies: Convection, aerodynamic, vacuum, press-vacuum, HD/MW, IR and ultrasonic, etc.

Top rating of manufacturing companies:

Falcon,
CATRES,
LLC "Intokorod",
Lauber,
eberl,
muhlbock,
hildebrand,
I.S.V.E.
and others.

The cost of installing foreign manufacturers is on average several times higher than domestic equipment.

These manufacturers together with the drying chamber provide a long-term warranty, delivery, installation and commissioning.

Contents Russian manufacturers of drying chambers In order for lumber to acquire the necessary qualities, durability and become suitable for mechanical processing, it must first be dried. This procedure consists in removing moisture and bringing its quantitative ratio to an acceptable level of 8 to 14%. Wood drying chambers from Russia may well provide the required quality. In our country we have […]

Contents Chinese Kiln Manufacturer Drying wood is a very responsible and time-consuming process that requires attention, specialized equipment and a lot of theoretical knowledge in the field of knowledge of wood as a natural material. The fact is that it consists of 70% of pores in which moisture either accumulates or collects after sawing, which makes the wood unsuitable for further […]

Contents Buying a press-vacuum dryer in Ukraine In order for wood to become durable and acquire the necessary practical qualities that make it possible to perform mechanical processing, it must be pre-dried. This process has been used since ancient times, only earlier preference was given to atmospheric drying under canopies or in the open air. Today, it is required to significantly accelerate it, so different manufacturers are developing new […]