At this stage, the moisture content inside the wood is already below the fiber saturation point. If the spray steaming treatment was not carried out in the previous stage, the outer wood would have lost its normal drying shrinkage condition and was fixed in a stretched state. Just like the incomplete dry shrinkage before the plasticization and fixing of the outer wood, the internal size and the outer layer are temporarily balanced, so the internal stress of the wood is also temporarily in a balanced state. At this time, if the test piece is sawed into a comb shape, the length of each tooth is temporarily the same, but after being placed, the moisture content decreases, and some teeth in the inner layer of the test piece will become shorter due to drying shrinkage.

Wood Internal Stress at Different Drying Stages The internal stress changes during wood drying can be divided into four stages. At the beginning stage of drying, the wood has not yet produced stress, and the moisture content of each part of the wood is above the fiber saturation point. If the test piece is cut from the middle of the material, the test piece is sawn into a comb shape, and the height of each tooth is the same as the sawn tooth. The original size before opening is the same. If the test piece is cut into two halves, each piece remains straight, which shows that there is no moisture content stress and no residual stress in the wood.

Before the wood drying kiln is used, a comprehensive and detailed inspection of its shell and equipment must be carried out to ensure the normal operation of the drying process. The specific inspection contents are as follows:(5)The operation of the drying process is carried out.

A monitoring system for a wood drying kiln having a housing with an interior wall surface, an area within the housing for placement of a charge of wood for drying of the charge of wood, and means for heating and humidifying the interior of the wood drying kilns, the monitoring system comprising:

Thermally modified wood namely charring wood, carbonized wood is through carbonization processing timber, carbonization, carbon under the word is a fire, as the name suggests, there is no water in the water must satisfy the condition of high temperature, wood strength for protection, control of coking process, must have a protective medium.

At this time, the moisture content of the wood has been distributed fairly evenly along the layers of the wood section, and the moisture content gradient from the inside to the outside is small. Stop shrinking, and the inner layer of wood should shrink with the removal of absorbed water, so that the shrinkage of the inner layer of wood is limited by the outer layer of wood, and the stress of the inner layer being stretched and the outer layer being compressed, the internal stress The situation is just opposite to that at the initial stage of drying. At this time, if the test piece is sawed into a comb shape, some teeth in the middle of the test piece are free to shrink after breaking away from the shackles of the outer layer, and their size is shorter than that of the outer layer.

CHIQIN Company is a company specializing in the production of various wood drying kilns and food drying kilns.  Safe production, reduce casualties and property losses has been the most important work of enterprises.

There are various types of drying equipment, including hot air drying equipment, vacuum drying equipment, freeze drying equipment, microwave drying equipment, spray drying equipment and rotary drying equipment. Each type of drying equipment has its unique working principle and application scenarios, which can be selected based on the characteristics of the material and drying needs.

In recent years, "high-frequency vacuum drying" has become very popular. This technology has been adopted by many factories due to its advantages such as small footprint, fast drying speed, and environmental friendliness, and has rapidly emerged as an emerging method for wood drying.

Microwave drying of wood is a new technology that has been increasingly used in domestic and international markets in recent years. Compared with traditional drying methods, microwave drying equipment has a series of advantages such as uniform heating, fast drying speed, no deformation, no cracking, good quality, and is conducive to continuous and automated production.