RU2525821C1 - Method of convective drying of rounded logs - Google Patents

Abstract

FIELD: woodworking industry.

SUBSTANCE: before drying over the entire length of each log 2 in the transverse direction the through diametric holes 1 are drilled uniformly for passage of drying agent through them. Drilling of all holes in each log is carried out under the same angle of inclination to the horizontal, and the angle of inclination is chosen from the condition in which during the construction of walls of buildings each subsequent log overlaps the openings of the previous one.

EFFECT: simplifying the technological process of drying of rounded logs, reduction of its complexity and power consumption.

1 tbl, 1 dwg

Description

The invention relates to wood processing technology, and in particular to the technology of convective drying of logs, mainly used as structural materials in the construction of walls of wooden buildings.

The prior art various technologies for drying wood - timber or logs using techniques and methods aimed at preventing cracking of both the outer and inner layers of wood during the drying process, for example:

- in the technical solution for A.S. USSR No. 100765 at the ends of the timber, cuts of various lengths are performed along the direction of the fibers;

- in the technical solution according to the patent of the Russian Federation No. 2163328 along the longitudinal axis of the beam or log on its opposite sides, grooves of various configurations are made and the air flow is guided along the grooves;

- in the technical solution according to the patent of the Russian Federation No. 2298139, a slot is made along the longitudinal axis of the beam or log in which a heat source is placed in the form of an electrically conductive heating element;

The above analogues have the same drawback, which consists in the complexity and energy consumption of wood drying technology by known methods.

A known method of drying wood, mainly logs according to the patent of the Russian Federation No. 2047064.

When this method is implemented, before drying begins, a log channel is formed in the core of the log, where the coolant is pumped, the drying volume is sealed with an elastic film, and the drying process is carried out by vacuumizing the drying volume and removing the spent coolant through the branch pipe.

With this drying method, the longitudinal wood fibers of the central and peripheral parts of the log dry out and shrink simultaneously and do not cause cracking of its surface. On the other hand, due to the presence of a through hole in the geometric center of the log, the rate of molecular movement of moisture from the center to its surface increases compared to traditional types of wood drying, which generally reduces the drying time.

The known method can be taken as a prototype of the claimed invention according to the main essential feature identical with it - the presence of a through hole in the geometric center of the log, which basically provides the technical result of the invention according to the prototype.

However, the prototype has disadvantages, consisting in the great complexity of this method, the complexity of the process to ensure the specified drying conditions and its energy consumption.

The objective of the invention is the improvement of the technology of convection drying of logs with a simultaneous reduction in the drying time.

The technical result is the simplification of the technological process of drying logs, reducing its complexity and energy consumption.

The task can be achieved, and its technical result can be achieved by using the claimed invention - a method of convective drying of logs, mainly used as structural materials in the construction of walls of wooden buildings, in which before drying, along the entire length of each log in the transverse direction evenly drill through diameter holes to pass through them a drying agent. In this case, drilling of all holes in each log is carried out at the same angle of inclination to the horizontal, and the angle of inclination is selected from the condition under which, when erecting the walls of buildings, each subsequent log overlaps the holes of the previous one.

Figure 1 shows the location of the holes in the dried logs when mounting the wall.

The claimed method of convection drying is applicable to cylindrical logs used as a structural material in the construction of walls of wooden buildings and previously prepared for this process, i.e. equipped with a platform pre-prepared along the entire length of the log for laying logs on each other, formed by a longitudinal selection of wood and copying the radial surface of the rounded log.

Before drying, the entire diametrical holes 1 are uniformly drilled in the transverse direction along the entire length of each log 2 in order to pass through them a drying agent (warm air) and remove evaporated moisture with it. In this case, drilling of all holes in each log is carried out at the same angle to the horizontal, and the angle of inclination is chosen so that when erecting the walls of buildings, each subsequent log 2 overlaps the holes 1 of the previous one (Fig. 1).

As an example of the implementation of the claimed method, the samples were dried from freshly cut pine logs with a diameter of 180 mm with a length of 60 mm and an initial humidity of 23%. Samples were dried at a temperature of 50-55 ° C for 180 hours. Samples were divided into two groups. In the first group, holes were not drilled in the samples. In the second group, in each sample, 5 holes with a diameter of 28 mm were drilled in the transverse direction evenly every 100 mm at the same angle of inclination to the horizontal. The moisture content of the samples was determined by the weight method after 60, 120 and 180 hours. The research results are presented in the table.

Table Duration of drying, hour Change in wood moisture% with the number of through holes, pcs. 0 pcs 5 pieces. 0 23 23 60 21.3 18.9 120 16.8 13.5 180 13,2 11.7

An analysis of tabular data indicates that in samples with through holes in the transverse direction, humidity is 12.8% less than in samples without holes.

Using the claimed invention will significantly simplify the process of convective drying of logs, reduce its complexity and reduce energy consumption. The presence of through holes in the transverse direction will contribute to the rapid and uniform heating of the log over the cross section, which will accelerate the drying process. In addition, the uniformity of heating the wood with openings ensures simultaneous drying of the fibers of the central and peripheral parts of the log, which leads to a decrease in internal stresses arising in the log during the drying process and eliminates the formation of cracks on its surface.

Claims (1)

The method of convective drying of round logs, mainly used as structural materials for the erection of walls of wooden buildings, characterized in that before drying, along the entire length of each log in the transverse direction, uniform diametrical holes are drilled uniformly for the drying agent to pass through them, while all holes are drilled each log is carried out at the same angle of inclination to the horizontal, and the value of the angle of inclination is chosen from the condition under which when erecting walls along Each subsequent log overlaps the holes of the previous ones.