Method for drying wood and an apparatus for the implementation thereof

Abstract

The invention relates to the field of wood processing. The drying method consists of the repeated alternation of the cycles of blowing air heat-carrier over the wood at atmospheric pressure while heating the wood to an average volume temperature of 80-100 DEG C, applying a pulsed rapid vacuum with a working pressure of not more than 50 mm Hg over a time of up to 10 s with free moisture being forced out without the phase transformation of the water into vapour until a constant temperature of the wood is established, and relieving the vacuum to atmospheric pressure by supplying air heat-carrier, the wood being blown over and the vacuum relieved using air heat-carrier with a temperature of 150-300 DEG C at an excess pressure of not more than 0.07 MPa.; The apparatus for implementing this method for drying wood includes two drying chambers connected to a cooled receiver by pipes having fast-acting valves, said cooled receiver being connected in series to a second receiver and to a vacuum pump by means of a pipe with a vacuum seal. The first receiver is fitted with spiral guides for streams of vapour-droplet medium along a tangent to the inside diameter of the receiver shell. The drying chambers are connected to a heat-carrier preparation and delivery system.

Description

technical field [0001] The invention relates to the field of wood treatment, in particular, the invention relates to wood vacuum drying technology, and the invention can be used in wood industry, wood treatment industry and other industries. Background technique [0002] The method currently used is pulsed vacuum drying of construction materials by means of repeated alternating cycles of heating, while the material is blown by means of heating medium and vacuum, and during each cycle the heating and vacuum are applied for a duration equal to the blowing time. There is adiabaticity between processing operations. Blowing was performed within 6 minutes at a temperature of 160° C. and at a moisture content of 15 g / kg operating with a gas-air mixture. Vacuum treatment is performed within two minutes at a residual pressure of 300 mm Hg (cf. a.c. USSR No. 1000701, class. F 26B 5 / 04, published г. 1981). The apparatus includes a drying chamber and a vacuum pump connected to a recei...

AI Technical Summary

Problems solved by technology

[0003] Disadvantages of this method and this device include: high energy consumption due to the long time required to generate the vacuum and to carry out the drying operation; the poor quality of wood drying in the cross-sectional area; and the final moisture content along the The length of the pile is quite uneven

The above formula for determining the pipe diameter does not appear to be correct

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