Abstract: Method and apparatus for the observation of luminous phenomena, especially for the observation of luminous effects excelling in the ambient luminous intensity by their high luminous intensity. By the present invention the above aim is fulfilled by a method and a an apparatus by which light transmission is varied depending on the intensity of the light effect futhermore, variation of light transmission is effectuated by a signal higher than the final control signal. The decrease of light transmission is fast and is in conformity with the intensity of the luminous effect, and lack or failure of external supply do not affect safety of observation.

Abstract: Phase-contacting plates are defined by a plurality of pivotable flow-blocking members arranged in alternating rows in which the respective blocking members thereof pivot in opposite direction to the respective blocking members of adjacent rows, the respective blocking members of each row overlapping successive members thereof, each blocking member being deflectable by the upward flow of the low-density phase and controlling the downward flow of the high-density phase, each flow-blocking member being formed by at least one elongated flow-blocking flap pivotable about a transverse axis at one end thereof, and at least one moment-equalizing element operatively connected with the flow-blocking flap.

Abstract: A method for removing the moisture adhered to surfaces of bodies and simultaneously for adjusting the surface temperature of the bodies to a predetermined value, in which air or steam having a temperature within the range of .+-.10 degrees centigrade of the surface temperature to be reached is streamed along the surface of the body, wherein an average velocity of stream of the air or steam is as follows: ##EQU1## wherein v.sub.1 is the average velocity of stream of the air or steam,g is the gravitational acceleration (g=9.81 m/s.sup.2),t.sub.v is the dynamic viscosity of the moisture in the state of its removal,G.sub.1 is the specific weight of the air or steam in the state or removal of the moisture,v.sub.v1 is the velocity of stream of the moisture at radius R.sub.1,R.sub.b is the hydraulic radius of the moistened surface,R.sub.1 is the hydraulic radius of the interface of the moisture and the air or steam,f.sub.1 is the degree of saturation of the air or steam,c is ##EQU2## wherein 0.

Abstract: A plate floor heat exchanger has a plurality of conductive mutually parallel plates spaced apart by narrow gaps defined by spacer bands which can have a streamlined shape and each of which are traversed by a plurality of tubes extending perpendicular to the plates. The spaces between longitudinal edges of these bands define flow channels for a fluid in a heat exchange relationship with the fluid traversing the tubes.