| 摘要 |
477,742. Preserving wood. VAUTHERIN, H. M. A. March 22, 1937, No. 8348. Convention date, March 28, 1936. [Class 140] Wood is preserved by treatment with steam in a closed space such as an autoclave at a temperature between 115 and 170‹ C., by injecting live steam at a pressure of 3 to 7 kgs./cm<2>. into the closed space at the beginning of the treatment and maintaining the temperature by heating radiators or the like. The treatment is continued for three to five hours until a cross-section of the wood is uniformly coloured. Preserving agents such as creosote may be simultaneously introduced by passing the steam through the heated liquid on its way to the autoclave. Alternatively, the wood may be impregnated with creosote under pressure at 75 to 80‹ C. before steaming. The optimum treatment temperature for fir and spruce is given as 150‹ C.
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