Full-automatic impregnation

First class impregnation in record time!

The new, full-automatic high pressure impregnation plant from WTT has been developed with the aim to be able to operate up to 16 hours without the need for manning of the plant.
The annual capacity of the full-automatic plants delivered so far varies from 26,000 m³ to 60,000 m³. They impregnate in hazard classes 3 and 4, with one operator for 8 hours - his job it is feed and empty the chain-driven charging and unloading area.
The autoclave is tilted 5 degrees during the process which facilitates the dripping off of superfluous  impregnation solvents via grooves and shiplays. When leaving the plant via the chain track, the wood packets are tilted transversely in 5 degrees so that solvent still present at the wood stickers and elsewhere can run off.
After a period of approx. 16 hours on the chain track the wood has dried so much up that it can be safely transported to the stock area. All superfluous impregnation solvent is lead back into the storage tanks by means of steel plate underneath the dripping off area.

Click here to see a video of a plant in operation! 

How does it work...?

All information about the wood packets (width, thickness,  length and m3) is scanned by means of a bar code reader and automatically sent to the control system, which – based on the information sent to it – then chooses the impregnation program suited for the charge in question. At the end of the process the impregnation data containing information on impregnation date and uptake amount  (kg/m3) is returned to the bar code.
The plant disposes of two storage tanks with automatic shift between impregnation hazard class 3 and 4 or between green or brown impregnation colour.
The autoclave is equipped with side walls (or ”baffles”) to reduce the amount of fluid to be pumped in and out of the plant which reduces the filling and emptying times dramatically (3-5 minutes). This very swift operation permits the plant to impregnate the wood to hazard class 3 and 4 in less than two hours and the capacity is thus able to impregnate 12 charges within 24 hours.
Moreover, the plant is equipped with particular powerful filling and emptying pump which enables it to operate with the Lowry process, i.e. process without the initial vacuum phase. This particular process reduces the uptake amount from 300 to 150 litres/m3 by doubling of the impregnation concentrate. This permits impregnation to hazard class 3 and 4 with one storage tank only.