Steam generator heated by combination of electric heat and condensation of contaminated process steam

A steam generator assembly, in particular a steam generator assembly used in connection with the mechanical preparation of pulp, for generating pure steam required in a subsequent process, such as in a drying of paper in a paper machine, by utilizing the condensation heat of contaminated steam coming from a preceding process, such as a grinding process, comprising:

• a steam converter;
• means for supplying water to be converted to pure steam to said steam converter;
• means for supplying contaminated steam to said steam converter;
• said steam converter utilizing the condensation heat of the contaminated steam from a process producing contaminated steam for generating pure steam;
• an electrical boiler connected in parallel with the steam converter for generating pure steam independently of said steam converter;
• at least one electrically energizable power electrode arranged within the electrical boiler, said at least one electrode adapted to generate steam when electrically energized and moistened and each electrode comprising an outer face;
• means for supplying water to the electrical boiler for selectively moistening the outer face of said at least one electrode to generate pure steam therein;
• and
• means for selectively controlling said water supplying means and the extent of the moistened area of the outer face of said at least one electrode and thereby the amount of pure steam generated by the electrical boiler;
• a common housing including a pure steam outlet in operative communication for receiving pure steam from an outlet of the steam converter and the electrical boiler;
• wherein the steam converter and the electrical boiler are arranged within said common housing so as to form a unified structure.