Abstract: A method for producing corrugated tubes of substantially high surface area for use in tube-in-shell heat exchangers which are particularly efficient for cooling water involves pointing a heat exchange tube at both ends to reduce the diameter substantially and increase the wall thickness of the pointed ends and then corrugating the tubes linearly. The tubes each having intermediate portions linearly corrugated to provide equally spaced deep corrugations extending in a straight line parallel to the axis of the tubes. The corrugations, which are equivalent to tubes, multiply the amount of heat transfer attainable from the point diameter selected for attachment to the tube sheets. The ratio of the surface area of the corrugated body portion to the surface areas of said reduced ends, per unit length, is in the range from about 1.5:1 to about 4:1. It also makes possible the contiguous relation of each tube to the surrounding tubes.

Abstract: A tube-in-shell heat exchange apparatus is disclosed for passing two fluids in countercurrent linear heat exchange having a tubular shell, a pair of header caps closing opposite ends of the shell, a pair of tube plates positioned at the ends of the shell defining inlet and outlet headers with the header caps, the header caps having an inlet opening in one and an outlet opening in the other opening into the inlet and outlet headers, each tube plate having a plurality of spaced openings, a plurality of heat exchange tubes, one for each of tube plate opening, having opposite end portions reduced in diameter and increased in wall thickness and fitted and sealed in the tube plate openings, the tubes each having intermediate portions linearly corrugated or convoluted to provide equally spaced deep corrugations extending in a straight line parallel to the axis of the tubes and forming a plurality of linear flow passages, and the shell having an inlet opening at one end and an outlet opening at the other end inside t

Abstract: An apparatus for heating a liquid by mixing combustion products therewith comprises a housing having a liquid reservoir compartment, a mixing chamber above the reservoir having a tortuous fluid flow path, a combustion chamber above the mixing chamber with a gas burner and apparatus for igniting and burning a mixture of air and fuel and an apertured water jacket at the upper end. A pump draws liquid from the reservoir and discharges it through the water jacket on the combustion chamber side wall to cool the burning mixture. The discharged liquid collects at the lower end of the combustion chamber and flows evenly throughout the tortuous fluid flow path (Raschig rings) in the mixing chamber to thoroughly mix hot combustion gases with the hot liquid mixture for maximum heat transfer. The mixture falls through an air space into the reservoir to separate the excess gases for venting to atmosphere. The heated liquid may be circulated through a hot water supply piping system for industrial usage.

Abstract: An apparatus for heating a liquid by circulating combustion products comprises a housing having a liquid-containing reservoir compartment and a burner compartment thereabove containing a fuel burner for burning a mixture of air and combustible gases, liquids or particulate solids. An electric motor mounted above the burner has a shaft extending downward into the liquid in the reservoir with an impeller on the lower end submerged in the liquid. Rotation of the impeller produces suction in the liquid drawing hot combustion gases into the liquid and disperses the same as hot gas bubbles which heat the liquid efficiently. A portion of the liquid is conducted from the reservoir and discharged close to the burner to cool the burning mixture. The heated liquid may be reycled through a hot water supply piping system for industrial usage. A coil submerged in the reservoir allows a second liquid to be heated thereby for use in a hot water supply system for residential or industrial usage.

Abstract: A novel metal tube corrugating die comprises a hollow die body with a plurality of die teeth in an internal cavity. The die teeth are flat with a curved edge extending diagonally into the die cavity providing a die corrugating tooth surface extending inward along a curved line. The die teeth are spaced uniformly around the interior of the die body. The die teeth are positioned somewhat on a helical line and are each tilted away from the other so that the planes of the individual teeth intersect substantially on the longitudinal axis of the die at a point foreward of a plane normal to the die body and passing through all of the die teeth. A mathematical equation expresses the optimum clearance between the die teeth. When a thin-walled, hollow tubing is inserted in the die, held against rotation, and the die body rotated relative to the tubing, the die teeth corrugate the tubing.

Abstract: A novel corrugating die for metal tubing is disclosed comprising a hollow die body having one or more die teeth positioned in the internal cavity thereof. The individual die teeth have a flat shape with a curved surface and extend diagonally into the die cavity providing a die corrugating tooth surface extending from the surface of the die cavity inward along a curved line. Preferred embodiments of the die utilize a plurality of die teeth spaced uniformly around the die cavity. The angular positioning of the die teeth is such that the teeth lie somewhat on a helical line.When a thin-walled, hollow tubing is inserted into the die at the end adjacent to the roots of the die teeth and held against rotation and the die body rotated relative to the tubing, the die teeth corrugate the tubing in somewhat the manner of a thread cutting die. When only one or two die teeth are used, the die teeth must be set at a very low helical pitch. As the number of die teeth is increased the helical pitch may be greater.