US2829836A - Separator for vapor and condensate - Google Patents

Description

April 8, 1958 .w. H. M KENz lE ,8

SEPARATOR 0R VAPOR AND CONDENSATE Filed 001;. 9, 1952 Q I 2a 42 I as 54 IN V EN TOR.

477'0RNEY Iii.

2,829,836 7 SEPARATOR FOR VAPOR AND CONDENSATE H. MacKenzie, New York, N. Y.

Application October 9, 1952, Serial No. 313,929

3 Claims. (Cl. 236-59) tirely satisfactory in avoiding loss of steam, various improvements have been proposed. One device contains 'a water discharge ,valve actuated by a temperature sensi tive compound metal bar, working on the principle of flexing due to unequal coeflicients of expansion of the face and back of the bar. Certain disadvantages are inherent in this device, however, and it has achieved no measurable commercial success insofar as known to me. The separator of the present invention is actuated by a thermosensitive element that provides positive movement of the closing valve in both directions under the influence of flexing or straightening of the element, a guide for the valve stem, preventing chattering of the mechanism during use, an increased rate of discharge of the liquid condensate for a given size of opening in the discharge valve, and means for supporting the working parts of the separator on the cover of the apparatus so that, when the cover is removed, the parts requiring attention are also removed and made readily accessible.

Briefly stated, the preferred embodiment of the invention comprises a steam and condensate separator with a thermosensitive, resiliently flexible metal strip acting positively upon-the valve to move it into closing position or into open position with temperature change on the strip. In the preferred embodiment the invention comprises the combination of such mechanism with one or more of the following features: tapered inside walls of the outlet for the condensate, a rigid stem for the valve and a guide for the stem, two points of support for the temperature sensitive actuating element and means attaching it at a midportion to the valve stem in limitedly movable relation to the stem, and an oversize hole at the position of attachment of the heat sensitive element to the valve stem. In a modification, the outlet closing member is integral with the compound metal strip, as, for instance, a rounded projection pressed from the strip at such position as to register With and close the outlet for liquid condensate when the temperature of the strip falls to that showing accumulation of liquid condensate to be discharged. This modification is disclosed in a divisional application.

The invention will be illustrated by description in connection with the attached drawings to which reference is made.

Fig. 1 is a plan View of my separator partly broken away'for clearness of illustration and partly in section.

Fig. 2 is a sectional view on line 22 of Fig. l.

U i e States; Patent j Fig. 3 is a sectional view on line 3-3 of Fig. 2.

Referring particularly to the drawings, denotes generally a container or casing for the vapor and condensate to be separated, in this case steam and water. This container includes a cover 12 and a bottom or lower part 14.

Extending from the cover is flange 16 and from the bottom flange 18, the two flanges together forming a partition, flange 16 being provided with a bore to receive the support 20 for the operating mechanism.

The container includes inlet 22 for steam and such water as may be admitted with the steam. It includes also drain line 25 for the water condensate.

The operating mechanism includes the support 20 referred to above, bracket 24 fixed to said support and extending outwardly therefrom, compound (here bi-) metal strip 26 that is thermosensitive and that is so mounted that the end portion 28 of the strip moves with rise in temperature in direction away from the'position of valve head 30 (to the left in Fig. 2) and thus forces the valve head 30 in the direction of the seat 32 in the condensate outlet tube with straight tapered interior formed by liner 36, so tapered as to become more narrow in the direction of flow of condensate through the liner. This tapering increases the rate of discharge for a given area of opening in the valve seat at the narrow end of the outlet; this increase may be as much as 14%.

The end portion 28 of the thermosensitive strip is provided With hole 38 through which passes the valve stem 40, the valve stem in the form shown being a threaded rod, nut 42 and lock nut 44 being screwed on the threaded part. These nuts jointly form a member with grooved part engaged in the hole 38 in the metal strip 26, the hole being oversized with respect to the grooved part, so that the strip 26 may expand longitudinally without any shift of the position of the said grooved part, and the temperature sensitive strip being attached thusto the valve stem in manner allowing limited movement of one with respect to the other. The thermosensitive strip extends transversely with respect to the valve stem.

The cover of the container includes viewing glass 46 and bolts 48 which hold the cover to the lower part as shown in Fig. 1. Bolts 50 and metal frame 52 hold the viewing glass 46 in place against the rest of the cover of the container. Fastening elements such as bolts 53 fit tightly in holes in the strip as shown in Figs. 2 and 3.

The support 20 includes guide 55 provided with bore 54 to receive the rigid valve stem 49, this bore being slightly oversize with respect to the diameter of the valve stem 50 that the valve stem is slidably movable within the guide. Support 20 is generally tubular and has large lateral openings 59 (Figs. 1 and 3) to permit the condensate collected in casing 10 to flow into the tapered liner 36and past the open valve 30 to the drain 25.

The mechanism includes also means shown at 56 for rigidly mounting one end of the thermosensitive metal strip 26 upon the outer end of bracket 24 and in fixed relation to the valve seat and the other stationary parts of the mechanism. Means 56 include the bolt element 53 securing an end of the thermosensitive strip to the bracket 24 at a position approximately as far from the lower part 14 of the container as the other end of the strip is from the cover 12 of .the container, as will be noted from Fig. 2. This central spacing of the strip minimizes disturbances from variations of temperatures outside the container.

The nut 58 acts with the flange 60 on the support for the operating mechanism to hold the operating Patented Apr. 8, 1958' mechanism firmly within the bore within the part 16. Thus when cover 12 is removed, after removing bolts 48, the entire valve structure and its operating mechanism are removed, facilitating inspection, repair, cleaning and replacement of parts.

The operationof the mechanism will be largely'evident from the description of .the drawings that has been given.

When the separator is used as a steam trap, the steam is admitted to the container through line 22 and the liquid separated escapes through outlet tube or liner 36 and finally through the drain 25.

The nuts 42 and 44 are set at a low temperature and at such position that the valve shoulder72 will be drawn loosely against the valve seat 32 at an elevated ternerature below that at which the separation of steam from condensate is actually to be effected. As the strip reaches the said elevated temperature at which the heat sensitive strip 26 loosely contacts the valve seat, the steam pressure directed against valve head 30 or its shoulder 72 will still maintain an opening between this shoulder and the valve seat, the opening being caused by flexing of the flexible but resilient strip 26 under the pull placed thereon by the steam pressure on the valve closing parts. When the'strip flexes to the point at which the steam pressure is no longer able to maintain an open position of the escape valve, then the shoulder '72 and the seat 32 are brought into a closing position and held there by the resiliency of the yieldable thermosensitive strip 26. The tension on the strip causes the strip to flex in one direction only.

Example In a typical example the following were the conditions. The thermosensitive metal strip Was stainless steel (iron chromium alloy) with nickel incorporated in differcnt proportions in the two parts of the strip. This causes unequal temperature coeflicients of expansion of the two parts, the part of higher coefiicient being on the side toward the valve seat, i. e., to the right in Figs. 2 and 4. Such thermosensitive strips of stainless steel composition are described in U. S. Patent 2,332,416 and sold under the trade name Cofiex." Another strip of similar composition that I have used extensively is sold under the trademark Rufex currently being changed to the name Aquaflex. This material when tested by A. S. T. M. methods shows flexivity of 0.0000100 (flexing with temperature change) and modulus of elasticity of 25,000,000 lbs./sq. in. The construction used in this example is that shown in Figs. 1, 2, and 3. The width of the compound metal strip was 1 in., the over-all length 2%in., the working length (between the point of support on the bracket 24 and the grooved part around the valve stem) 2.15 in., and the thickness of the theriosensitive bimetal strip 0.035 inch. The nuts 42 and 44 were set at a temperature of 6870 F. and at such position as to give a clearance of 0.0350.037 in. between shoulder 72 and seat 32.

The composition of the bimetal strip selected in this example was such that the portion of the strip provided with the hole to receive the groove part of the nuts 42 and 44 moved 0.001 inch to the left in Fig. 2 for each 1." F. rise in temperature.

This means that the movement of the heat sensitive strip should close the outlet for an increase of 35-37 F. in the temperature, except for the vieldability of the strip 26 under tension from the valve stem. This yielding under tension is so great with the strip of kind described that the outlet was not actually closed tight until th temperature reached 180 F.

in another commercial operation, the setting at 70 F. was such as to give a clearance of 0.053 inch between seat 32 and shoulder 72. The condensate was found to be discharged at 206 F., with a maximum variation of 2 F. on the temperature recording chart. The saving in steam over results with the conventional trap previously in use was 600 lbs. an hour with a 17 F. rise-in temperature of the material being heated by the steam.

At that time the valve closes, the composition in the container is mostly steam which it is desired to retain in the system. When the temperature falls appreciably below this temperature the thermosensitive strip with the original cold setting described flexes under the tension sufliciently to provide an opening between shoulder 72 of the valve and seat 32, 'so that liquid condensate present escapes and passes to .the drain 25. Because of the springiness of the flexed thermosensitive strip, there isno chattering of the mechanism during use. Since the valve is closed in etfectby this sensitive spring action, the mechanism is more accurate in its separation of steam from condensate than is the case with conventional steam traps; it gives a large saving in steam consumed in many types of operations utilizing steam and separating the condensate as itaccumulates inthe-system. T he materials of construction of the various partsof my separator are usual in devices of this kind except as noted herein. Thus, the container may be constructed of cast steel or of pressed steel sheet of adequate thickness to withstand the pressures to which it will be subjected by steam during use of the container. The container alternatively maybe constructed of brass: or stainless stcel, although such more expensive materials are not normally required. 1

The thermosensitive metal strip is constructed of the stainless steel compositions described although there may' be used for this strip other kinds of metals, such as'face and back composition consisting largely of one of the following pairs of metals: copper-aluminum, eonstantan alloy-brass, nickel-copper. If some of these alternative materials are chosen in place of the stainless steel, they are us d in strips of thickness to give a resilient'pull on the valve stem 40 of about the amount realized'with the stainless steel construction under the same circumstances.

For the liner tube 36 inside the outlet, for'thevalve' suitably in hardened condition. For-these working "parts bronze, brass and other accurately machineable materials of construction may be used although stainless steel is better and gives the desired sharpness of separation of steam from condensate. In any case all the-moving'parts of the mechanism and also the valve seat and valve'stem guide should be non-corrodible under the conditions of use and non-softening at'the highest temperature'to which they are exposed during use. Also they must be resiliently flexible, that is, subject to bending by a force applied to them and to springing back to the original position when the stress is removed.

The separators described are relatively simple and .inexpensive. They are effective for the purposes described, in separating hot vapors from substantially cooler liquid condensates, with a minimum of loss of vapor with the condensate separated.

It will be understood that it is intended to cover all changes and modifications which do not constitute departures from the spirit and scope of the invention.

What I claim is:

l. A separator for steam and condensate comprising, in combination, a casing providing a closed chamber having an inlet for steam and an outlet or drain for the condensate; a transverse partition fixed withinthe casing'between said inlet and outlet and dividing'the chamber into two compartments; a support removably fixed to saidpartion and extending into both said compartments; a bracket fixed to said support and extending outwardly therefrom; a valve seat fixed to one end of .said support and positioned on the outlet side of said partitiom a valvezseatable on said valve seat and having a stem rigidly secured asaasse thereto; said removable support being hollow and having lateral openings to permit condensate to enter and flow past the valve seat, and also having an axial bore on the end remote from said valve seat for slidably receiving and guiding said valve stemfthe valve stem extending axially through the center of said support and beyond said axial bore to a pointspaced from the inlet side of said partition; a valve-operating mechanism located on the inlet side of said partition and including a thermosensitive resiliently flexible bimetal strip, fastening means fixedly securing one end of said bimetal strip to the outer end of the bracket at a point well spaced from the valve stem, the other end of said'bimetal strip having a hole that is spaced slightly from the extremity of the strip and that is oversize with respect to the valve stem, said valve stem passing through said oversize hole, and adjustable coupling means connecting the end of the strip that has said hole to said valve stem, said adjustable means providing an abutment for the strip on each side, but permitting relative movement between the strip end and the valve stem, so that when the strip flexes due to expansion or contraction arising from heat changes, it will thrust the valve stem axially in one direction or the other to seat or unseat the valve, thus controlling flow of condensate to the outlet or drain.

2. The invention defined in claim 1, wherein the support encloses and rigidly carries a straight condensatedischarging tube or liner having a tapered bore becoming smaller in the direction of flow of the condensate, the valve seat being formed on that end of the tube from which the condensate is discharged, the valve having a sloped annular shoulder portion which seats on said valve seat in the closed position of said valve.

3. The invention defined in claim 1, wherein the casing and the transverse partition are split in a plane that is to one side of the inlet and outlet; said inlet and outlet being at opposite ends of the casing and on one part of the split casing; bolts holding the parts of the casing together; that part of the transverse partition which is fixed to the other part of the split casing carrying said support, said valve seat, said valve, and said valve-operating elements, so that when said other part of the split casing is removed from said one part, the inlet and outlet are fully exposed, and said support, said valve, said valve seat and said valve-operating elements are all accessible for inspection, removal, cleaning and servicing.

References Cited in the file of this patent UNITED STATES PATENTS 24,896 Wilson July 26, 1859 1,204,265 Freeman Nov. 7, 1916 1,219,515 Whittelsey Mar. 20, 1917 1,310,026 Lippert July 15, 1919 1,667,935 Hutchinson May 1, 1928 1,814,512 Hetherington July 14, 1931 1,907,145 Broman May 2, 1933 2,629,553 Velan Feb. 24, 1953 FOREIGN PATENTS 278,261 Germany Sept. 26, 1914 OTHER REFERENCES Catalog 500 (front and back covers, and pages 5 and 7 relied upon) ofVelan Engineering Company, One Exchange Place, Jersey City, New Jersey, copyright 1951.

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