US 4,805,692 AGranted

Condenser for water purification apparatus

AssigneePure Water, Inc.

InventorsDavid G. Palmer, Keith L. Vacha

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Abstract

A distillation type of water purification system has a raw water inlet valve for admitting raw water continuously to a boiling tank at a rate greater than the rate at which raw water is converted to treated water. A drain valve located at the bottom of the boiling tank is energized by a raw water level sensing means whenever the raw water level reaches a predetermined level, to discharge water from the boiling tank. Treated water is stored in a storage tank having a pump for discharging treated water to the user upon demand. A single conductivity sensor in the storage tank controls the pump to allow it to operate only if the sensed conductivity is above a first predetermined value but not at or above a second predetermined value greater than the first value. An improved condenser has two sets of tubes, each set is arranged in a pair of planes oriented transverse the flow of cooling air with the tubes parallel. The internal cross-sectional area of one set is about twice that of the other. Steam and condensate flows serially through the larger diameter tubes and then through the smaller diameter tubes in a flow countercurrent to the cooling air stream.

A condenser for condensing steam to water in a water purification system having means to convert raw water to steam and cooling means for establishing a flow of cooling fluid from a cooling fluid inlet over said condenser, said condenser comprising:

a steam inlet;
a water outlet;
a set of first tubes having opposite ends and an internal steam flow path, substantially all of said first tubes having a uniform first predetermined cross-sectional area;
said first tubes being parallel with each other and disposed in a first plane that is transverse the flow of cooling fluid;
first interconnect means for connecting adjacent ones of said ends of said first tubes such that steam and condensate will flow in a planar serpentine fashion serially through said first tubes;
second interconnect means for connecting said steam inlet to a first one of said ends of said first tubes that is not connected to another one of said ends defining an upstream portion of said first tubes with respect to the flow of steam and condensate;
a set of second tubes having opposite ends and an internal steam flow path, substantially all of said second tubes having a uniform second predetermined cross-sectional area that is less than said first cross-sectional area;
said second tubes being parallel with each other and disposed in a second plane that is parallel with said first plane, said second plane being disposed between said first plane and said cooling fluid inlet;
third interconnect means for connecting adjacent ones of said ends of said second tubes together such that steam and condensate will flow in a planar serpentine fashion serially through said second tubes;
fourth interconnect means for connecting a second one of said ends of said first tubes that is not connected to another one of said ends of said first tubes and is downstream of said upstream portion to a first one of said ends of said second tubes that is not connected to another one of said ends of said second tubes defining an upstream portion of said second tubes with respect to the flow of steam and condensate;
and
fifth interconnect means for connecting a second one of said ends of said second tubes that is not connected to another one of said ends of said second tubes and which is downstream of said upstream portion of said second tubes to said water outlet, whereby steam and condensate will flow through said tubes countercurrent to said cooling fluid.

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Abstract

Claims6