Abstract: An expansion valve wherein a plunger slidably fitted in a hollow member for sliding movement and opening and closing valve ports formed in the hollow member is driven by an electromagnetic force, and two chambers defined between opposite ends of the plunger and the hollow member are maintained in communication with each other through a pressure equalization passageway formed in the plunger. The expansion valve is capable of allowing a refrigerant to flow therethrough without any resistance offered to its flow and having ability to allow reversible flow of the refrigerant to take place with high responsiveness.

Abstract: A greenhouse of an underground heat accumulation system wherein the radiant energy of the sun or wasted thermal energy is accumulated in the soil below the floor of the greenhouse over a prolonged period of time, and spontaneous release of the accumulated energy into the interior of the greenhouse begins in the wintertime due to a time lag of heat transfer through the soil. The release of the accumulated energy lasts throughout the winter.

Abstract: A heat-transfer wall kept at a low temperature so that hot vapor brought into contact with its surface condenses thereon. The surface is grooved at a fine pitch, having thin and sharply tapering ridges in between, with shallower fine-pitch grooves or notches formed in the ridges. The wall may be that of a tube, the grooves may consist of a continuous root in the form of a helix, and the ridges may be bent into the grooves to form rounded crests. The wall contour is made by forming fine-pitch shallow grooves crosswise by knurling and then forming fine-pitch deep grooves by cutting and turning up the surfaces in a plowing manner, for example on a lathe. A grooved die may be used to deform and bend the edges of the ridges toward the deep grooves.

Abstract: A method of manufacturing a heat-transfer wall for vapor condensation comprising the step of forming on the heat-transfer surface, a number of shallow grooves substantially in parallel at a fine pitch, and then forming, on the heat-transfer surface and in the direction across said shallow grooves, a number of grooves deeper than the shallow grooves at a fine pitch by cutting and turning up the heat-transfer surface in the plowing manner. Said method may further comprise a subsequent step of curling the edges of the ridges formed in the above-mentioned step into said deep grooves.

Abstract: An apparatus for manufacturing heat transfer tubes for use in evaporators and coolers for freezers, air conditioning units, refrigerators, and the like, with close machining tolerances. It forms cavities, with small openings communicating them with the outside, on the inside of a tube, through three steps of forming a multiplicity of alternate grooves and ribs in parallel on the inner surface of the tube, forming cuts in the concentrically directed crests of the ribs, and then forcing the crests sidewise so that the crest of each rib is bent down onto an intermediate part of the adjacent rib to form a cavity in between.

Abstract: A heat exchanging wall including a base member made of a material comprising graphite as its principal component and a resin as a binder, and a thin outer coat member made of similar material as the material for the base member and applied to one surface of the base member. The material for the base member is cast in a mold having a finely ribbed inner wall surface so that the base member may be formed in such one surface thereof with fine linear grooves. Portions of the thin outer coat member corresponding in position to the grooves in such one surface of the base member are formed with a multitude of small apertures. The heat exchanging wall constructed as aforementioned has high corrosion-resistant characteristics and high heat transfer capabilities, so that the wall is resistant to all corrosive fluids.

Abstract: A condensing, a heat-transfer wall for liquefying vapor having a temperature higher than the wall by bringing the vapor in contact therewith. There are provided many parallel grooves in the basic surface of the heat-transfer wall, thereby defining ridge portions or build-up portions thereamong. These ridge portions have their tip portions tapered at sharp acute angle. Recessed or concave portions are provided in the tip portions of these ridge portions, and these recessed portions have their surfaces inclined to the basic surface of the heat-transfer wall. The width of the respective grooves ranges from 0.05 to 2.5 mm, and the depth thereof is not more than 10 mm. The thickness of the respective ridge portions ranges from 0.01 to 2.5 mm, and the height there of is not more than 10 mm. The depth of the recessed portions ranges from 0.02 to 0.8 times the depth of the grooves, and the pitch of recessed portion is not more than 2.0 mm. The width of the tip portions of the portions is 0.01 to 1.

Abstract: An air cooling apparatus having a cooler including a plurality of fins arranged in substantially parallel relationship with a predetermined spacing therebetween and heat transfer tubes extending through the fins in a plurality of positions in the fins is further provided with at least one defrosting device having a plurality of projecting members of a width slightly smaller than the spacing between the fins which projecting members are each located between the adjacent two fins. The defrosting device is mounted for rotation about the heat transfer tubes and operative to remove frost from the surfaces of the cooler while rotating which frost has been formed during the operation of the air cooler.

Abstract: According to the present invention, fluid rotary machines including a turbo-compressor, turbo-desiccator, turbo-refrigerator, turbo-generator and the like are of such an arrangement that supporting shafts corresponding to impellers in number and a gear train changing R.P.M. of said supporting shafts to the optimum R.P.M. of the impellers mounted on said supporting shafts are provided, so that the respective impellers can operate at the optimum R.P.M. individually.

Abstract: A heat transfer wall for boiling liquids having a multiplicity of minute tunnels parallelly extending and spaced a distance of not more than 1 mm under the metal wall surface in contact with liquid. Each tunnel is communicated with the outside by a multiplicity of tiny holes formed at regular intervals of not more than 1 mm along the tunnel. The wall surface portion is in one piece with the wall body. The holes combinedly account for from 2 to 50% of the total surface area of the wall. The regularly formed holes are substantially triangular shaped. The wall is made of either copper or aluminum.

Abstract: A heat transfer pipe for use in a heat exchanger such as air conditioner, freezer and boiler, wherein grooves are formed in the inner wall surface of the pipe, which are by far finer in size than the grooves that have been provided for the purpose of increasing the heat transfer area in general, and slanting relative to the axis of pipe, to thereby improve the heat transfer rate without increasing the pressure loss caused to the fluid flowing through the pipe.