Method of and apparatus for injecting treating-liquid into wood material and porous inorganic material, and method for destroying ray parenchyma cell walls and aspirated pit pair

A method of destroying ray parenchyma cell walls and aspirated pit-pairs of broadleaf wood, and injecting treating liquid into broadleaf wood comprising the steps of:

• a) a pressure-reducing step of exposing the broadleaf wood to a gas pressure no greater than atmospheric pressure, and maintaining the gas pressure for at least 30 minutes to purge gases out of said broadleaf wood,
• b) an initial pressure-applying/injecting step of immersing said broadleaf wood in a treating liquid at ambient temperature under a liquid pressure in the range of 1 to 10 kg/cm.sup.2, and maintaining the liquid pressure for at least 20 minutes to inject said treating liquid into tracheid of said treated wood,
• c) a treating-liquid injecting step of increasing the liquid pressure of said broadleaf wood with injected treating liquid at ambient temperature up to a final applied liquid pressure having a maximum value of 50 kg/cm.sup.2 in a stepwise manner, comprising a plurality of pressure increases of 5 to 20 kg/cm.sup.2 each, each said pressure increase being followed by maintaining the increased pressure for at least 10 minutes to further inject said treating liquid under pressure into said broadleaf wood while dissolving any gases remaining in said broadleaf wood in said treating liquid, and
• d) a pressure-removing step of reducing the liquid pressure on said broadleaf wood from said final applied pressure to atmospheric pressure over a period of at least 20 minutes to prevent said broadleaf wood from being broken due to abrupt expansion of any gases dissolved in said treating liquid which is injected into said broadleaf wood.

A method of injecting treating liquid into a stone material comprising the steps of:

• a) a pressure-reducing step of exposing the stone material to a gas pressure no greater than atmospheric pressure, and maintaining the gas pressure for at least 60 minutes to purge any gases out of said stone material,
• b) an initial pressure-applying/injecting step of immersing said stone material at ambient temperature in a treating liquid under a liquid pressure in the range of 1 to 10 kg/cm.sup.2 and maintaining the liquid pressure for at least 60 minutes to inject said treating liquid into cracks inside said stone material,
• c) a treating-liquid injecting step of increasing the liquid pressure of said stone material at ambient temperature up to a final applied liquid pressure having a maximum value of 50 kg/cm.sup.2 in a single step, and maintaining the final applied pressure for at least 30 minutes to inject said treating liquid under pressure into said stone material while dissolving any gases remaining in said stone material in said treating liquid, and
• d) a pressure-removing step of reducing the liquid pressure on said stone material from said final applied pressure to atmospheric pressure over a period of at least 20 minutes to prevent said stone material from being broken due to abrupt expansion of any gases dissolved in said treating liquid which is injected into said stone material.

An apparatus for injecting treating liquid into wood materials and porous inorganic materials comprising:

• a pressure vessel for accommodating a material to be treated in a sealed state;
• a depressurizer means for reducing gas pressure in the pressure vessel;
• a constant volume liquid delivery means for delivering a treating liquid to the pressure vessel and pressurizing the pressure vessel to a predetermined liquid pressure under dynamic pressure;
• and
• a pressure-removing means for the pressure vessel and comprising container means having therein a gas pressurized to the predetermined liquid pressure, fluid connection means between the container means and the pressure vessel and valve means for selectively venting the container means to atmosphere, whereby release of the pressurized gas to atmosphere reduces the pressure in the pressure vessel.

A method for injecting treating liquid into wood or stone material, comprising the steps of:

• a) placing the wood or stone material in a pressure vessel of an apparatus comprising a pressure vessel for accommodating a material to be treated in a sealed state;
• a depressurizer means for reducing gas pressure in the pressure vessel;
• a constant volume liquid delivery means for delivering a treating liquid to the pressure vessel and pressurizing the pressure vessel to a predetermined liquid pressure under dynamic pressure;
• and a pressure-removing means for the pressure vessel and comprising container means having therein a gas pressurized to the predetermined liquid pressure, fluid connection means between the container means and the pressure vessel and valve means for selectively venting the container means to atmosphere, wherein release of the pressurized gas to atmosphere reduces the liquid pressure in the pressure vessel;
• b) delivering the treating liquid to the pressure vessel in an initial step to an initial liquid pressure of 1 to 10 kg/cm.sup.2, maintaining said initial liquid pressure for at least 10 minutes, and subsequently increasing said liquid pressure to a final applied liquid pressure having a value of 30 to 50 kg/cm.sup.2 in a plurality of step increases of 5 to 10 kg/cm.sup.2 each, followed by a holding period of at least 10 minutes following each of said step increases;
• and
• c) venting the pressurized gas in the container means to atmosphere, to thereby reduce the liquid pressure in the pressure vessel.