US2435686A

US2435686A - Condensation pump

Info

Publication number: US2435686A
Application number: US635381A
Authority: US
Inventors: George A Kuipers
Original assignee: Distillation Products Inc
Current assignee: Distillation Products Inc
Priority date: 1945-12-15
Filing date: 1945-12-15
Publication date: 1948-02-10
Anticipated expiration: 1965-02-10

Description

Feb. 10; 1948. e. A; KUIPERS CONDENSATION PUMP Filed DG. 15, 1945 FIG 1.

FIG. 2.

GEORGE A.KUIPERS INVENTOR A TTORNE Y Patented Feb. 1O, 1948 I CONDENSATION PUMP George A. 'Kuipers, Rochester, N. Y., assignor to Distillation Products, Inc., Rochester, N. Y., a corporation of Delaware Application December 15, 1945, Serial No. 635,381

6 Claims. (Cl. 230-101) This invention relates to an improved condensation pump provided with a jet of the umbrella'type.

Condensation pumps of the inverted Langmuir type having umbrella jets and made from metal spinnings have been in use for a considerable period of time. However, there has-always been a problem involved in obtaining accurate throat clearances between the inside and outside walls of the umbrella jets. Recourse has been had to wire spacers and the use of a series of closely spaced holes has also been quite common. However, both of these methods have been only partially satisfactory and they'are expensive and therefore not good methods for constructing on a mass production basis.

This invention has for its object to provide an improved condensation pump provided with at least one umbrella jet. Another'object'is to provide an improved construction for the umbrella jet in a condensation'pump whereby the jet clearance can be set in'a simple manner and maintained during operation. Another object is to provide a condensation pump having an umbrella jet which can be economically constructed. Other objects will appear hereinafter. l

These and other objects are accomplished by my invention which includes a condensation pump having at least one umbrella 'je't formed of two concentric annular members which cooperate to form the inside and outside walls of the jet, th inside concentric annular member having an outwardly turn-ed edge over which the outside concentric member fits and which serves to accurately space ,the inside and outside annular members.

In the following examples and description I have given several of the preferred -embodiments of my invention but they areset "forth forthe purpose of illustration and not in limitation thereof.

In the accompanying drawings, wherein like end which is adapted to be connected to the syspump such as the 2 tem to be evacuated. Numeral m designates a conduit integral with casing 4 which is adapted to be connected by a flange l2 to a backing pump (not shown). Numerals l4, l6 and I8 designate cylindrical members mounted one above the other so as to form an internal cylindrical chimney inside of and concentric with casing 4. Element 14 is expanded outwardly near the lowest portion thereof, as indicated by the numeral 20, so as to form a narrow annular space between it and cos. ing 4. Element I6 is superimposed over element l4 and is held in that position by the outwardly turned edge 22 at the top of element l4. Element I8 is superimposed on element It and is maintain-ed in the position illustrated by outwardly turned edge 24. Numeral 26 designates 'a. cap which fits over the top of the chimney assembly and which is maintained in the position shown by outwardly turned edge 28. Numeral 3'0 designates an anchor integral with the central portion of cap 26 to which is attached three spider legs 32 which serve to position the chimney assembly centrally within casing 4.

Referring especially to Fig. 2, it will be noted that outwardly turned edge 28 corresponds in diameter to the inside diameter of cap 26 so that when the two are assembled an accurately spaced umbrella jet having a throat diameter equalling the distance between 48 and 50 is formed.

The construction of outwardly turned

edges

22 and 24 and cooperating caps I 6 and I8, respectively, is entirely analogous to that discussed in detail in connection with jet 38. These cooperating members therefore form

jet nozzles

34, 36 and 38, which are adapted to pump in series and which are furnished with actuating vapors of a pump fluid. This actuating vapor is supplied by heating the base of the pump to a temperature sufiicient to vaporize the pump fluid indicated by the numeral 40, the vapors pass upwardly into

jet nozzles

34, 36 and 38 through

holes

42, 44 and 46 respectively. The vapors are then reversed in passing into these jet nozzles and pass downwardly as high velocity streams and pumping in tandem entrain gases which diifuse from the system to be evacuated into the upper part of the pump casing. The pump fluid is condensed on the air cooled walls of casing 4 and flows by gravity downwardly between the casing 4 and element 14 andthence back into the body of pump fluid 40. Pumped gases pass into conduit l0 and are removed from the system by the backing pump (not.

shown) connected to flange l 2.

One feature of my invention which may be used in conjunction with any type of umbrella jet is the use of large diameter for

holes

42, 44 or 46 so that the total area for passage of vapor at this point is at least equal to and preferably larger than the throat area of the umbrella jet. The throat area of the umbrella jet is that area which exists between the inside and outside wall of the jet at a point before the vapors start to expand. Thus in Fig. 2 the throat area is the area between 48 and 50. By thus constructing the jets and holes the working vapor expands only when it reaches the expansion portion of the nozzle and therefore has greater pumping velocity. Expansion in passing through

holes

42, 44 and 45 is a waste and reduces the pumping capacity. In accordance with my improvement the vapors reach the throat of the umbrella jet without having undergone expansion and then expand in the jet proper in a beneficial manner and location. we take an example in which the vapor is expanded from 1,000 a to 1 At the smallest crosssectional area the pressure is about 600 and the kinetic energy of the vapor stream is equal to the energy available in expanding the vapor from 1,000 to 600 a. Since this is a large portion of total energy of expansion, it is important that the vapor stream at this point be flowing in the right direction. Thus it makes a considerable diiference whether the total area of the holes or the area of the annulus is the smaller. Ideally, thetotal area of the holes should be several times as large as the area of the annulus sothat the full 1,000 ,u boiler pressure can obtain in the region above the annulus.

While I have illustrated my invention by means of a three-stage umbrella type pump, it is manifest that the invention is not limited to a pump having this number of stages and that the invention is applicable to a single stage or multi-stage pump so long as it is provided with at least one umbrella jet constructed as described.

What I claim is:

1. In a condensation pump having at least one umbrella jet, the improvement which comprises two concentric annular members cooperating to form the inside and outside walls of the umbrella jet, the inside annular member being provided with an outwardly turned edge over which the outside portion fits and which turned edge serves to accurately space the inside and outside walls of the umbrella jet.

2. A condensation pump, comprising a, cylindrical casing having a boiler at the lower end thereof and adapted to be connected at the other end to a system to be evacuated, at least one umbrella jet positioned centrally within the casing and adapted during operation to propel gases from the upper end of the casing toward the lower end thereof and an exhaust conduit connected at the lower end for removing pumped gases, said umbrella jet'being formed of two concentric annular portions which cooperate to form the'inside and outside walls of the jet, the inside portion being provided with an outwardly turned edge over which the outside portion fits and which serves to accurately space the inside and outside walls of the jet.

3. A. condensation pump comprising a cylindrical casing having a boiler at the lower end By way of explanation suppose thereof; and adapted to be connected at the other end to a system to be evacuated, a plurality of umbrella, jets positioned centrally within the casing and adapted during operation to propel gases from the upper end of the casing toward the lower'end thereof and an exhaust conduit con nected at the lower end for removing pumped gases, said umbrella jets each being formed of two concentric annular portions which cooperate to form the inside and outside walls of the jet, the inside portion being provided with outwardly turned edge over which the outside portion of the jet fits and which serves to accurately space the inside and outside walls of each of the jets.

4. A condensation pump, comprising a cylindrical casing having a boiler at the lower end thereof and adapted to be connected at the other end to a system to be evacuated, at least one umbrella jet positioned centrally within the casing and adapted during operation to propel gases from the upper end of the casing toward the lower end thereof and an exhaust conduit connected at the lower end for removing pumped gases, said umbrella jet being formed of two concentric annular portions which cooperate to form the inside and outside walls of the jet, the inside portion being provided with an outwardly turned edge over which the outside portion fits and which serves to accurately space the inside and outside walls of the jet and means for delivering vapors to the jet which means has a larger vapor delivery area than the throat of the umbrella jet.

5. A condensation pump comprising a cylindrical casing having a boiler at the lower end thereof and adapted to be connected at the other end to a system to be evacuated, at least one umbrella jet positioned centrally within the cas' ing and adapted during operation to propel gases from the upper end of the casing to the lower end thereof, an exhaust conduit connected at the lower end for removing pumped gases, said umbrella jet being formed of two concentric annular portions which cooperate to form the inside and outside walls of the jet, the-inside portion being provided with an outwardlyturned edge over which the outside portion fits and which serves to accurately space the inside and outside walls of the jet, an annular, non-expanding passage constituting the throat of the jet and openings between the inside wall of the jet and the throat passage, which openings have a total area at least as large as the area at the point where the throat and the umbrella jet join.

6. In a, condensation pump, a 'vapor delivery chimney provided with a plurality of peripherally positioned apertures, an umbrella jet having one end connected in fluid tight relation with said chimney and extending downwardly and substantially concentrically with said chimney and overlying said openings to provide an annular passage of uniform transverse cross sectional area, the total area of said openings being at least as large as the transverse area of the passage, and a flared portion of said jet extending downwardly from the concentric portion of the jet to provide a second annular passage of increasing cross sectional area in fluid communication with said first annular passage,

GEORGE A. KUIPERS.

REFERENCES CITED The following references are of record in the file of .this patent:

UNITED STATES PATENTS Number Name Date 1,367,865 Crawford Feb. 8, 1921 2,112,037 Malter Mar. 22, 1938 2,150,676 Embree Mar. 14, 1939