US1429503A - Treating peat for manufacturing an insulating material - Google Patents

Description

Patented Sept. 19, 1922.

RUDQLE GRAEFFE, OF BRAND-ERBISDORF, NEAR FREIBERG, GERMANY.

TREATING- IPEAT FOR MANUFACTURING AN INSULATING MATERIAL.

5N0 Drawing.

To all whom it may concern:

I Be it known that I, RUnoLF GRAEFFE, a' subject of Germany, and residing at Brand- Erbisdorf, near Freiberg, in Saxony, Germany, have invented certain new and use- ,ful Improvements in Treating Peat for Manufacturing an Insulating Material (Germany, Gr 48 ,717 VI/80 22nd July, 1919, Germany, G 49,491 VI/80 Nov. 11th, 1919), of which the following is a specification.

.This present invention relates to an improved treatment of peat for manufactur-' ing-a high-valued insulating material which byv the special treatment hereinafter described is much improved with regard to the insulating materialheretofore known consisting of a mixture of dried peat with a powdery binding substance which is put into heating drums 'or the like after being mixed in order to be melted- This process could not however provide a really valu able, insulating material nor could this be obtained by mixing wet peat with respective binding substances on account of the great iabsorbing capacity of the peat, the latter always tending to regain its original degree of moisture, of*which ithadfbeen deprived by drying or presslng, from the surroundng atmospheric air or the surroundlng -iflmasonry and besides the peat having a liability to shrink and swell and thereby changing its volume, according to its being wet or dried which is a great disadvantage tocits use as insulating material or the like.

the observation that in order to obtain a really; good insulating material it is necessary to. destroy the absorbing capacity of the peat and the shrinking and swelling'qualities of the same, this being obtained by the present process in the most perfect manner as follows e Peat in any desired form and state, that is to. say marshy or dried in pieces or re- Y duced to fibres is boiled in water, whereby the marshy water may be used, and a tossing-tub or the like being adapted to thoroughly disintegrate the peat while boiling; After a boiling time of about one hour, in which time the peat deposits itself on the bottom of the boiler, coal-tar-pitch is put into the boiling peat, saidpitch being in a state of foam by preheating the same to 200 C., whereby it will be observed that the coaltar-pitch in this state is adapted to Application filed January 6, 1921. Serial No. 435,567.

thoroughly saturate the fibres of the peat which are completely dissolved by boiling. lVhile the boiler is being filled with the foaming coal-tar-pitch the tossing-tub must be set atv rest and will be actuated again, when all the coal-tar-pitch has been put into the boiler, the boiling process being simultaneously continued, whereby the coal-tarpitch is homogeneously and thoroughly mixed with the peat-pulp. This is effected by the liquid pitch entering thoroughly into the dissolved fibres of the peat which are enlarged to their utmost volume by the boiling process, hereby bursting the wet walls of the cells and covering the fibres, inside and outside with a thin layer of pitch, whereby the foam forms a kind of medium, by which the coal-tar-pitch is introduced into the peat.

The effect of the process is as follows (1) The perfectly even cover of the peatfibres with a thin well-adhering layer of coal-tar-pitch forms after the solidifying fast but nevertheless elastic cover round each fibre which prevents the same from either swelling or shrinking.

(2) The destroying effects of the chemicals whichwere contained in the coal-tar pitch on the slimy, swelled and colloidal substances of the fibres, taking from the same their water-absorbing qualities.

(3) The entrance of the finest parts of.

the coal-tar-pitch into the ends of the fibres,

whereby in the solidifying of the coal-tar pitch such a pressure is exercised upon the cells of said fibres that the same will presently burst, their capacity of absorbing water being destroyed'in this way. v

. The finished pulp of peat and coal-tar influence of any desired pressure, that is to say steam or compressed air, whereby the wateris withdrawn from the mass.- Now the moulds are put into hand-or-hydraulic presses and the mass is reduced to about one half or one quarter of its previous volpitch may now be treated with respect to ume. As soon as these moulds hereby obtained are cooled they are ready for use. It is however advisable to store the same some short time before using in order that the same may dry a little more, Whereafter the moulds are still less liable to breakage and disforming by pressure or the like. The same are perfectly even and show the characteristics as cited above.

It is however possible to form the peat even after being dried in the above described manner, in wetting the same a little but not more than to about 25% of its dry weight and only in such a manner that no dust may rise in working the peat. This wet material is again filled into fast and well closed moulds and is reduced to about one third of its previous volume in heatable hand-or-hydraulic presses.

As in pressing the mpulds of the peat-pulp the moulds used thereby are to be heated again to about 100 0, whereby a quick evaporation of the water which had been added to the peat before filling it into the moulds is effected, which results in a chemical process very favourable to the pressing action and the peat retaining into once given form so that in a very few minutes a perfectly even and homogeneous body is produced Within the pressing forms.

In order to obtain moulds ofstill greater firmness the peat may be mixed during its boiling process with a certain quantity of hot wet potters clay or else, if the pressed bodies must have a special resistance against heat, kieselguhr must be added besides such potters clay.

Finally the above described material may be used for manufacturing artificial stones for building purposes in adding thereto cement, lime, gypsum or the like.

It must be still observed that according to the above described invention a very valuable material is obtained. It may now be possible that in certain instances a less valuable and therefore less expensive material may be used as well. In this case it is sufficient to ad dto the peat before boiling. the same a well heated (unto 100 C.) quantity of coal-tar-pitch. By boiling both these ingredients together a good mixture of the fibres and the pitch may be obtained though the same will be less even and perfect than the mixture according .to the original form of the present invention.

A third possibility exists in preparing a still more valuable material than in the first-named example by the peat being not, only dessicated but roasted at a still higher temperature and changed into coal, whereafter it may be treated as described in the first form of the process. Hereby a material is obtained which possesses quite an extraordinary insulating capacity against cold and heat, so that it may be used in special cases. In further treating this material the mass may be filled into roasting pans instead of being simply dried after the mixing process and roasted therein in respective quantities. This repeated roasting may be prolonged till the formation of coal, Whereafter the roasted mass is filled into heatable presses in order to be pressed into moulds orlike forms. It is evident that such forming may be done in the same time with the" brought to foam by. preheating to about 200 C. being mixed ith said peat during the boiling process Wherea'fter the thorough ly mixed material is dried and treated ac cording to its further use that is pressed and formed into" plates, substantially as described. 7

2. The herein described insulating material composed of peat being boiled in water and coal-tar-pitch having been brought to foam by preheating the same to about 200 C. being miXedfW-ithsaid peat thereto during theboiling; process, where-- after the thoroughly mixed material is pressed in moulds While hot and before being dried, said moulds being brought under the influence of steam or air under pressure whereafter the moulds are pressed inhan'dor-hydra-ulic presses, substantially as de scribed.

8. The herein described insulating Ina-- teri'al composed of peat and coal-tar-pitcli,

said peat being roasted before its being boiled with the foaming coal-tar-pitch and the finished material being roasted again to turn into coal during its treatment in the; presses or moulds, substantially as described. In testimony whereof I aflix my signature in presence of two Witnesses.

RUDOLF GRAEFFE.

lVitnesses Dr. LANDESKROENER, O. REINI'QKE,