Abstract: The heat exchanger is made up of a shell having a coaxial tubular outer and inner wall with end plates attached thereto to enclose a tubular shell cavity provided with an inlet and outlet for a first fluid. Within the shell cavity is a spiral coil of tubing through which flows a second fluid. The coil is wound helically about the axis of the shell and sized to fit the inner and outer walls with limited radial clearance. The coils are axially spaced from one another to define a spiral flow path within the shell cavity for the fluids to first flow. The radial and axial clearance establish a spiral flow path and an axial flow path which are relatively sized to cause the first fluid to travel in a spiral motion, thereby enhancing heat transfer between the first and second fluids. Also, an enclosed central receiver, include communication with the shell cavity, may be formed within the inner tubular wall which serves as a fluid accumulator or reservoir.

Abstract: The heat exchanger is made up of a shell having a coaxial tubular outer and inner wall with end plates attached thereto to enclose a tubular shell cavity provided with an inlet and outlet for a first fluid. Within the shell cavity is a spiral coil of tubing through which flows a second fluid. The coil is wound helically about the axis of the shell and sized to fit the inner and outer walls with limited radial clearance. The coils are axially spaced from one another to define a spiral flow path within the shell cavity for the fluids to first flow. The radial and axial clearance establish a spiral flow path and an axial flow path which are relatively sized to cause the first fluid to travel in a spiral motion, thereby enhancing heat transfer between the first and second fluids.

Abstract: The heat exchanger is made up of a shell having a coaxial tubular outer and inner wall with end plates attached thereto to enclose a tubular shell cavity provided with an inlet and outlet for a first fluid. Within the shell cavity is a spiral coil of tubing through which flows a second fluid. The coil is wound helically about the axis of the shell and sized to fit the inner and outer walls with limited radial clearance. The coils are axially spaced from one another to define a spiral flow path within the shell cavity for the fluids to first flow. The radial and axial clearance establish a spiral flow path and an axial flow path which are relatively sized to cause the first fluid to travel in a spiral motion, thereby enhancing heat transfer between the first and second fluids.

Abstract: An apparatus for automatically monitoring the level of water in a swimming pool, or the like, by monitoring the level of a float within a float chamber supported by water siphoned from the pool system, for detecting when the level of water has fallen a predetermined amount or distance below a predetermined desired level and for controlling the input of fresh water into the pool system in response to the detected level for restoring the water in the pool to the predetermined desired level as determined by the position of the float on the siphoned water within the float chamber being restored to a float position indicative of said predetermined desired level of water in the pool.

Abstract: An improved method and apparatus for automatically monitoring the level of water in a swimming pool, or the like, by monitoring the level of a float within a float chamber supported by water siphoned from the pool system, for detecting when the level of water has fallen a predetermined amount or distance below a predetermined desired level and for controlling the input of fresh water into the pool system in response to the detected level for restoring the water in the pool to the predetermined desired level as determined by the position of the float on the siphoned water within the float chamber being restored to a float position indicative of said predetermined desired level of water in the pool.