US2643051A - Two-stage condenser - Google Patents

Description

June 23, 1953 F. B. DOYLE TWO-STAGE CONDENSER Filed Dec. 18, 1950 Patented June 23, 1953 TWO-STAGE CQNDENSER Frank B. Doyle, Raynionmm; assignor to Guardite Corporation, a. corporation of Delaware Application December 18, 1950, Serial No; 201,458

1 Claim.

This invention relates to a multiple stage condenser and more particularly to a two stage condenser adapted to be contained within a single housing and to employ a single condensing fluid passing directly from the first chamber to the second chamber and communicating sequentially the first and second stages of an evacuation system with a third stage of evacuation being connected with a gas outlet in the second chamber.

The processes described in Merriam and Wiles Patent No. 2,080,179, issued May 11, 1937, require the handling of large quantities of condensible gas and the establishment of high vacuum within a' very short period of time. Previous to this invention these results have been accomplished by the use of multiple stage steam evacuation systems with a separate condenserfor each stage of the ejector system. In my copending application, Serial No. 82,963, filed March 23, 1949, there is disclosed and claimed a condenser system for use with a multiple stage steam ejector system. The system therein described provides three condensing chambersconnected sequentially to the first, second and third stages of the steam ejectors, all resulting in a compact chamber which may be placed in a very limited space. r e

7 The present invention provides an integrated condenser system havingtwo chambers capable of being used with a three-stage evacuation system. As will be shown, the first chamber is connected with the outlet of the first stage of the evacuation system, the second chamber is likewise connected to the second stage and the third stage of the evacuation system is a mechanical vacuum pump connected to the gas outlet in the second chamber. A space is provided within the second chamber for separating entrained water particles from the-gas before it leaves the chamber. The chambers are arranged to employ a single source of condensing liquid passing directly from the first chamber to the second.

' The 'invention'i's'illustrated in the drawings in which the single figure is a side elevation partly in section and partly broken away of th evacuation system. This figure is somewhat diagrammatic since the steam connections, being conventional, are not shown in order that the device may be clearly understood.

In the drawings, the chamber In is to be evacuated to the desired extent. The first stage steam ejector ll communicates through a nipple [2 with the vacuum chamber. The operation of a steam ejector is well known and is not here claimed. Therefore, the steam connections to .merely complicate the drawings.

the steam ejectors are not shown since they would However, of course, each steam ejector is provided in conventional form with the necessary steam connections and valve controls therefor. In actual operations, automatic controls for pressure, temperature and other conditions are provided at appropriate points in the system.

The effluent gases from the first stage ejector ll enter the first condenser chamber I5 tangentially through opening [6. Condensing water is supplied to chamber l5 through line I3 which passes centrally upwardly through the chamber and terminates immediately below a plate l4. bracket ll holds the line 13 in place. The plate [4 extends between opposite walls of the chamber over the end of line is leaving spaces between its longitudinal edges and the walls of the chamber for passage of gases past the plate. Inasmuch as the water is under pressure and the chamber is under a substantial vacuum, one of about one to two inches of mercury absolute, the water enters with considerable force and impinges upon the plate M, producing an umbrellashaped sheet which then impinges upon the wall of the chamber. The water falls into the tangential stream of efliuent gases. These gases are normally steam and non-condensible gases, such as air.

Uncondensed steam and non-condensible gases from the first chamber pass through line l9 to the second stage steam ejector 20 .wherein additional steam is used as a propelling force to increase the pressure and direct the gases through the line 2| to a second condenser chamber 25. The water from the first condenser chamber passes by gravity through the drain l8 down the pipe 22 to a reservoir 23. This reservoir is maintained full of liquid and a sufiicient head of liquid s maintained within pipe 22 to balance the pressure difierence between the first and second condenser chambers. A pipe approximately five feet long is satisfactory with water and a pressure of one to two inches in the first chamber and four to six inches in the second chamber.

The effluent gases from the second stage ejector V second chamber 25. A plate 34 extending across the shell divides the interior of the shell into two 4 ing by reference characters corresponding to the reference characters of the following table.

chambers and 25. The non-condensibles rise vertically in the space between the shell and the drain pipe 22, generally saturated with, water vapor, and carrying some water particles. The velocity in the space within chamber 25 above the reservoir 23 is low enough for most of the water particles to separate out and fall back.

An outlet fitting 3| is positioned in communication with the upper portion of the second chamlesser amount of entrained moisture are led to a mechanical vacuum pump 32. This pump dis.- charges through a line 33 to a separator (not shown). Since most of the entrained moisture is. separated from the non-condensible gases while still within chamber 25, the duty of thev separator (not shown) is substantially reduced.

The water overflowing from the reservoir 23 is collected in the bottom of the chamber 25 and eventually exists through the line 26 in the bottom of the shell 30. A liquid level controller 21 is provided having connections 28, 29 with chamber 25,, for use with a removal pump. If space permits a barometric leg may be substituted for pipe 26 in which case the liquid level controller may be omitted.

In normal steam evacuation systems as usually operated, evacuation is continuous. Consequently, the air removing equipment is small and air velocity through the condenser is low. The present system is designed for batch operation in which large volumes of air are moved at some times and small volumes at others. The equipment is, therefore, built for high air velocities. The mechanical vacuum pump 32 can handle large quantities of air as well as can the condenser chambers.

As, an example of the foregoing condenser sys-' tem, the following table gives the temperatures and pressures existing in the system under the operating conditions indicated. P represents the pressure in inches of mercury absolute and T represents the temperature in degrees Fahrenheit. The quantity of condensing water passing through the condenser is constant for all conditions ofv load listed. The temperatures and pressures, were taken at points indicated on the draw- The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the, art.

I claim:

A two-stage vacuum condenser comprising a single cylindrical shell having a separator plate intermediate its ends forming a first chamber immediately adjoining a second chamber within the shell, the first chamber being above the second chamber a water inlet, to the first chamber for supplying all of the condensing water used in the condenser; a reservoir in the second chamher for holding a sealing liquid pool; gravity drain means leading from the bottom of the first chamber' directly into the sealing liquid pool in the reservoir for conducting the water from the first chamber to the second chamber; steam ejection means for supplying steam and non-condensible gases to the first chamber at a level between. said water inlet and said drain means a, second steam ejection means for ejecting gases from the upper portion of the first chamber and supplying, it to the second condenser chamber below the top of the reservoir, said second chamber having an upper portion for collecting gases passing through a waterfall of liquid overflowing the reservoir andv removing entrained water therefrom, and an outlet in the upper portion of said second chamber for conducting said collected gases, out of the second chamber; and an outlet for the condensing water in the lower portion of said second chamber.

FRANK B. DOYLE.

References Cited in the file. of. this. patent UNITED STATES PATENTS Number Name Date 1,158,231 Kerr Oct. 26, 1915 1,307,705. Scanes. June 24, 1919v 1,436,108. Schmidt Dec 4:, 1923 1.715.457 Jones w.-a June 4. 1.929

FOREIGN PATENTS Number Country Date 697,736 Germany Oct. 21, 1940

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