Oy Partek Ab

Yhtyneet Paperitehtaat Oy

Oy Iampella Ab

Heikki Ahonen

Timo Kenakkala

Pertti Kokkonen

Reijo Hakulinen

Eero Lahti

A method of producing cement or concrete, comprising the step of adding fly ash to the cement or concrete at the production stage, the fly ash containing lime and reaction products from the reaction occurring between lime and sulphur oxides in connection with the desulphuration of flue gases. To avoid the disadvantageous effects of calcium sulphite and entringite reactions and to increase the used amount of fly ash containing desulphuration waste, the calcium sulphite is oxidized by hydrogen peroxide either before the production of cement or concrete or during the production.

Method of producing cement or concrete

A method for the manufacture of a mold out of mold material from a previous blank by machining each blank into a desired shape by means of a machine tool controlled by a computer utilizing a dimensioning data set. Each blank is manufactured by feeding an organic polymer material whose melting point is preferably lower than 150.degree. C. in liquid form into a box-shaped container which is open at the top and which corresponds to the dimensions of the desired mold. Waste polymer material from the blank upon machining is recovered and heated to a temperature higher than its melting point, whereupon it is fed onto an existing mold no longer needed, so as to provide a new blank for a new mold.

Method of manufacturing a reusable mold

A steam generator assembly, particularly for use in connection with the mechanical preparation of pulp, for generating pure steam required in a subsequent process, such as drying of proper in a paper machine, by utilizing the condensation heat of contaminated steam coming from a preceding process, such as a grinding process, includes a steam converter and electrical boiler arranged in a common housing to form a unified structure. The steam converter utilizes the condensation heat of the contaminated steam to generate pure steam from water supplied to the converter. The electric boiler is connected in parallel to the steam converter and includes electrodes adapted to generate steam when moistened by water supplied to the boiler from a separate water container in the housing. Selective control of the supply of water to the electric boiler and the extent to which the electrodes are moistened regulates the amount of pure steam generated by the electric boiler. The pure steam generated by the steam converter and electric boiler is discharged from the common housing through a steam outlet.

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Valkeakoski, Finland

Heikki Ahonen