US 4,731,164 A · Multi-stage flash evaporator

Abstract

A multi-flash evaporator having modular vertical cyclone chambers designed to generate a paraboloid of revolution providing an extended surface area for release of flashed vapors and attaining equilibrium. With multiple stages, the system incorporates deep loop seals to prevent blowby between stages at all levels of capacity and employs a vapor lift system to permit low pressure differentials between stages at high vacuum. The cyclone chambers employ an intermediate tangential inlet whereby the flashing vapors propel the liquid at higher velocities to generate a deeper paraboloid of revolution and centrifugally separate the heavier liquid from the flashing vapor. An anti-creep ring is interdisposed at the top of the cyclone to prevent the liquid from entering a mesh so only vapor impinges on the mesh and passes to the heat recovery condensers embodying a bayonet augmented tube heat exchanger.

Claims18

Dependent claims

A multi-stage flash evaporator comprising:

a. a plurality of cyclonic flash chambers each having a substantially vertical shell which is closed at the bottom and open at the top;
b. means for tangentially introducing a fluid to be evaporated in a liquid-vapor phase successively into each of said flash chambers in a first fluid flow zone intermediate said chamber's vertical height so as to establish a swirling body of fluid in each of said chambers and which defines a surface at and above said liquid-vapor introducing means, said surface being of a generally parabolic form about a substantially vertical axis;
c. means positioned below said tangential introducing means for tangentially discharging said liquid from each of said flash chambers, thereby generating a force for moving said liquid to the next successive cyclonic flash chamber's tangential introducing means in said liquid-vapor phase flow;
and
d. means for vertically discharging said vapor from the upper portion of each of said flash chambers to a second fluid flow zone wherein said vapor is condensed.

2 more elements

A flash multi-stage flash evaporator comprising:

a plurality of elongated flash chambers, each having a substantially vertical shell which is closed at the bottom and open at the top;
a condenser;
means for tangentially admitting fluid in a liquid-vapor phase into a first fluid flow zone of each of said flash chambers;
means for causing said fluid to vaporize causing the vapor to flow into said condenser;
means positioned below said tangential introducing means for tangentially discharging said liquid from each of said flash chambers, thereby generating a force for moving said liquid to the next successive cyclonic flash chamber's tangential introducing means in said liquid-vapor phase flow;
and, means for vertically discharging said vapor from the upper portion of each of said chambers, said condenser including:
a. a substantially horizontal outer shell having an elongated center section, an inner end having a first tube sheet closure and a closed distal end;
b. at least one thin gauge tubular sheath having a closed end adjacent, but spaced from said closed distal end of said shell and an open end facing said first tube sheet closure of said shell;
c. means for forming a plurality of third fluid flow zones between the outer surface of said sheath and said shell wherein said vapor is condensed;
d. a bayonet tube concentrically positioned in at least one of said sheaths, said bayonet tube piercing said first tube sheet closure, and having an outer portion extending at least through said first tube sheet closure and an inner portion terminating in an open end spaced from the closed end of said sheath;
and
e. means for forming a second fluid flow zone with second fluid flow therethrough, wherein said second fluid is heated in turbulent flow, said second fluid flow zone including the annulus formed between said bayonet tube and the inner surface of said sheath.

9 more elements

Dependencies are inferred from the claim text.

Multi-stage flash evaporator

Life of this patent

Multi-stage flash evaporator

Life of this patent

Abstract

Claims18