Method of drying, concentrating by evaporation, or distilling heatsensitive substances

Claim 1

IN A METHOD OF DRYING, CONCENTRATING BY EVAPORATION OR DISTILLING A HEAT-UNSTABLE SUBSTANCE OF THE CHARACTER OF BLOOD, SERA, PLASMA, HORMONE PREPARATIONS AND THE LIKE AT A LOW TEMPERATURE IN VACUO, THE REQUISITE HEAT BEING PRODUCED IN THE SAID SUBSTANCE BY MEANS OF HIGHFREQUENCY ELECTRICAL ENERGY, SAID SUBSTANCE BEING PLACED BETWEEN THE ELECTRODES, THE STEP OF ADJUSTING THE ELECTRIC FIELD STRENGTH AND THE AIR PRESSURE IN THE TREATING ZONE CONSTITUTING THE SPACE BETWEEN THE ELECTRODES SO THAT THE SAID FIELD STRENGTH F DOES NOT EXCEED A VALUE MEASURED IN VOLTS PER CENTIMETER OF THE DISTANCE BETWEEN THE ELECTRODES WHICH IS DETERMINED BY THE EQUATION F=3331/3.P VOLTS PER CENTIMETER, P DENOTING THE AIR PRESSURE IN MILLIMETERS OF MERCURY, THIS MUTUAL RELATIONSHIP BETWEEN FIELD STRENGTH AND AIR PRESSURE BEING SUCH AS TO ESTABLISH ONLY ION CURRENTS OF A STRENGTH AND EXTENT SUCH THAT THE RESULTANT LUMINOUS ZONES ARE REMOTE FROM THE SUBSTANCE BEING TREATED, WHEREBY UNDESIRED OVERHEATING OF THE LATTER IS AVOIDED.