US2554765A

US2554765A - Dry seal gas holder

Info

Publication number: US2554765A
Application number: US703853A
Authority: US
Inventors: John W Allen
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-10-17
Filing date: 1946-10-17
Publication date: 1951-05-29
Anticipated expiration: 1968-05-29

Description

y 1951 J. w. ALLEN 2,554,765

DRY SEAL GAS HOLDER Filed Oct. 17, 1946 2 Sheets-Sheet 1 FIG. 5.

6/15 INLET I/vvm TOR JOHN W 5mm 18w A T'TOENE Y May 29, 1951 J. w. ALLEN DRY SEAL GAS HOLDER Filed O6t. 17, 1946 2 Sheets-Sheet 2 ;N W. M m M -m W 2 m W w 0 J Y B Nuc Patented May 29, 1951 UNITED STATES EATENT OFFICE DRY SEAL GAS HOLDER John W. Allen, Chicago, 111., assignor to John H. Wiggins, Chicago, Ill.

Application October 17, 1946, Serial No. 703,853

4 Claims. 1

This invention relates to piston-type gas holders of the general kind in which the space or joint between the peripheral edge of the piston and the side wall of the storage chamber is sealed by a flexible, curtain-like sealing means, commonly referred to as a dry seal, and particularly gas holders of the type that are equipped with a backing and reinforcing structure that maintains the dry seal in a certain approximate shape or condition during the rise and fall of the'pi'ston, and effectively absorbs forces exerted on said dry seal by the pressure in the storage chamber of the apparatus.

One object of my invention is to provide a design for dry seal gas holders of the particular type mentioned, which lends itself to the construction of large size gas holders of great storage capacity, in which the gases stored in the apparatus are maintained under a relatively high pressure.

Another object is to provide a gas holder of the particular type mentioned, in which the re inforcing structure used to control the approximate shape or form of the flexible, curtain-like piston-sealing means (the dry seal), and to absorb pressure exerted on the same by the stored gases, is of novel construction and arrangement, and is of such design that it does not appreciably increase the overall height of the casing or housing of the apparatus, or, in other words, make it necessary to provide a space of considerable size above the piston, or between the piston and the roof of the housing to receive the backing and reinforcing structure for the piston sealing means.

And still another object of my invention is to provide a gas holder of this particular type mentioned, in which the structure used to control the approximate shape or form of the curtain-like piston sealing means, effectively absorbs the external pressure created by the gas on said sealing means during a part of the stroke of the piston. Other objects and desirable features of my invention will be hereinafter pointed out.

Briefly described, my improved gas holder comprises a stationary casing or housing provided with a vertical side wall, a verticallymovable piston in said casing that is adapted to; form the top wall of the storage chamber of the apparatus, and a flexible, curtain-like sealing means herein illustrated as an element constructed. of gas-tight fabric or other suitable flexible material, 'attached. to the peripheral edge of the; piston and to; the side wall of the Cir housing. During the cycle of operations of the apparatus the above mentioned flexible piston sealing element is backed up and reinforced by a stiff, vertically-movable member of substantially tubular or cylindrical shape in general form or outline, arranged vertically between the peripheral edge of the piston and the side wall of the housing, in such a way that the bottom edge of said vertically-movable backing member normally contacts or is. engaged by an intermediate portion of said curtain-like piston sealing element, i.'e., an annular portion of said sealing element located between the outer edge of said sealing element, that is attached to the side wall of the housing, and the inner edge of said sealing element that is attached to the peripheral portion of the piston. When the piston is at the end of its downward stroke, or, in other words, in its lowermost position, the said vertically-movable backing and reinforcing member occupies such a position that it serves as a back stop for the outer portion of the piston sealing element, i. e., that part of said sealing element disposed between the point of connection of said sealing element with the side wall of the housing and the annular intermediate part of said sealing element that contacts with or is engaged by the bottom edge of the vertically-movable backing and reinforcing member. At such times the pressure of the storage chamber causes the said outer portion of the piston sealing element to be pressed inwardly against the outer face or side of the vertically-movable backing member, thereby setting up compression forces in said member. During the first portion of the upward stroke of the piston, said verticallymovable backing member remains stationary or at rest, thereby causing the upward movement of the piston to fold the flexible sealing element around said member and move the inner portion of the sealing element (the part lying between the piston and the annular intermediate part of the sealing element engaged by the bottom edge of the backing member) into such relationship with said backing member that the pressure in the storage chamber causes the said inner portion of the sealing element to be pressed against the inner face or side of said backing member, i. e., that side or face of said backing member which is presented to or disposed in opposed relation to the peripheral edge of the piston. Accordingly, during this portion of the cycle of operations of the piston, the above mentioned backing member not only serves as a back stop which prevents the outer portion of the piston sealing element from flexing inwardly, towards the piston, but it also serves as a back stop which prevents the inner portion of the sealing element from being flexed outwardly, towards the side wall of the housing, by the pressure exerted on the sealing element by the medium confined in the storage chamber, the inner and outer portions of the piston sealing element being arranged back to back with the backing member lying between the same. Thus, it will be seen that during the first portion of the upward stroke of the piston, the inner portion of the sealing element, disposed between the piston and the backing member is progressively applied to said backing member. Said backing member then starts to move with the piston in the same direction that the piston is traveling, and at the same speed as the piston. This action or operation causes the outer portion of the flexible sealing element to be progressively stripped off the outer face of the backing member and progressively applied to the side wall of the housing, the inner portion of the sealing element remaining in snug engagement with the inner face of the backing member. By the time the piston reaches the end of its upward stroke, the major part of the outer portion of the sealing element is backed up by the side Wall of the housing, and the major part of the inner portion of the sealing element is backed up and held against outward flexing by the backing member. In order to prevent the inner portion of the sealing element from flexing inwardly, into overlapping relationship with the piston when the piston is at the end of its downward stroke, and during the first portion of the upward movement of the piston, the piston is preferably provided at its peripheral edge with a vertically-disposed annular member that serves as a back stop and reinforcing device for the inner portion of the sealing element during this portion of the cycle of operations of the piston. The pressure in the storage chamber holds the inner portion of the sealing element in snug engagement with the outer face or side of the backing member on the piston, and during the time the piston is moving into the horizontal zone in which the previously mentioned vertically-movable backing member is then lying at rest, said inner portion of the sealing element is progressively stripped off the back stop member on the piston and progressively applied to the inner face or side of said vertically-movable back stop member, as previously explained. Usually, the back stop member on the piston will be made about half the height or depth of the vertically-movable back stop member, but if desired, the piston can be provided with a relatively shallow back stop member and a plurality of vertically-movable, annular or tubular back stop members, arranged in concentric relation, can be used to control the shape assumed by the flexible sealing element and to prevent said sealing element from being strained or damaged by an abnormal pressure in the storage chamber. If the apparatus is equipped with only a single verticallymovable back stop member that co-acts with a back stop member on the piston to control the approximate shape or form of the flexible piston sealing element, said vertically-movable back stop member is so mounted and actuated, that during the upward stroke of the piston, the back stop member on the piston moves into telescoped relationship with the vertically-movable back stop member, and when the piston is at the end of its upward stroke, the vertically-movable back stop member does not extend upwardly a sub stantial distance beyond the top edge of the back stop member on the piston. Similarly, when the apparatus is equipped with a plurality of vertically-movable back stop members that coact with a back stop or fender member on the piston, the vertically-movable back stop members are so mounted and actuated, that during the upward stroke of the piston, they move into telescopic relation with each other and with the back stop member on the piston, and when the piston is at the end of its upward stroke, the vertically-movable back stop members do not extend upwardly substantially beyond the back stop member on the piston. By constructing the controlling means for the piston sealing element in the manner just described, I am able to reduce the height of the side wall of the housing of the apparatus, and thus effect a considerable saving in the cost of a dry-seal gas holder. For example, making a single verticallymovable back stop member approximately twice the depth of the back stop member on the piston, results in only one-sixth of the total rise of the piston being required to be added to the side wall height, this extra side wall height being sufiicient to accommodate the height of the back stop member on the piston. When two vertically-movable back stop members are used, the back stop member on the piston is only onehalf the height of the intermediate verticallymovable back stop member, and said intermediate member is only one-hali the height of the outer vertically-shiftable fender, which gives the result that the only extra height required in the side wall of the housing to accommodate the height of the back stop member on the piston, becomes one-fourteenth of the total rise of the piston. The ability to make these various backing and reinforcing members of the above relative heights, is because the said members are of such construction that either throughout a part of their area or throughout the entire area, they take compression set up by the flexible piston sealing element against them, due to the gas pressure in the storage chamber.

The vertically-movable backing and reinforcing member or members, and the back stop member on the piston can be constructed in various ways without departing from the spirit of my invention, so long as they are of such design or construction as to be capable of successfully withstanding compression set up by the piston sealing element bearing against the same. Due to the fact that they are arranged outside of the storage chamber and form no part of the flexible element that is relied upon to maintain a gas-tight joint between the piston and the side wall of the housing, they do not need to be gas-tight. Therefore, I prefer to build said parts in the form of skeleton-like structures, each of which comprises two or more stifi, circular, horizontally-disposed members capable of taking compression, and joined together vertically by bars or, slat-like members that serve as vertical struts or posts which tie said horizontal compression members together and hold them in spaced relationship. One advantage of an open back stop and reinforcing member, 01' member of skeleton construction, is that the flexible piston sealing element can be readily seen and examined throughout its entire area when the piston is in its lowermost position. Also, said sealing element can be tested for leaks while under pressure, by painting said sealing element with soap suds or the like.

or support the' vertically-movable member or members in the annular space between the piston and the side wall of the housing, and to cause said member or members to move with the piston during a portion of the stroke of the piston.

Figure 1 is a vertical transverse sectional View of a dry-seal gas holder constructed in accordance with my invention, equipped with asingle vertically-movable backing and reinforcing member, the piston constituting the top wall of the gas storage chamber.

Figures 2, 3 and 4 are diagrammatic views illustrating the piston in various positions, Figure 2 showing the piston at the end of its downward stroke, Figure 3 showing the piston in the position where it picks up the vertically movable back stop member, and Figure 4 showing the piston at the end of its upward stroke.

Figures 5 and 6 are diagrammatic views, illustrating the construction and operation'of a gas holder provided with two concentric, vertically movable back stop members, Figure 5 showing the piston at the end of its downward stroke, and Figure 6 showing the piston at the end of its upward stroke.

In the drawings, the reference character 2 designates the vertical side wall of the housing of a gas holder of the dry-seal type, l designates the bottom of the housing, 3 designates the roof of the housin and 4 designates a vertically-movable piston in said housing that The piston 4 is herein il..-

lustrated as being equipped with a stabilizin or levelin mechanism, which may be of conventional construction, the stabilizing mechanism herein illustrated comprising one set of cables [2 and 12 attached to the peripheral portion of the piston at diametrically-opposed points and leading upwardly from same over pulleys l3 to a weight I I to which both cables are attached, and a second set of cables, only one of which, designated l2 is shown, attached to diametrically-opposed points on the piston and leading upwardly from same over pulleys to a weight (not shown), to which both of said second set of cables are attached, the pulleys that co-act with the first mentioned pair of cables being mounted in pulley housings l5 and the pulleys that co-act with the second pair of cables being mounted in pulley housings l5, as shown in Figure 1.

The dry-seal of the gas holder that is relied upon to maintain a gas-tight joint between the,

piston 4 and the side wall 2 of the housing, and still provide for the rise and fall of the piston, is formed by a flexible, annular-shaped element S, usually constructed of gas-tight fabric, attached at its inner edge to the peripheral portion of the piston and attached at its outer edge to the intermediate portion of the side wall 2 of the housing. The lower portion of the side wall 2 below the point at which the sealing element is attached to same must be gas-tight, but the upper portion of said wall need not be gastight, inasmuch as said upper portion of the wall 2 is outside of the gas storage chamber X, and its sole functions are to carry the

roof

3 and 6. .form a back stop-for part'ofthesealing'element S during a portion of the upward stroke of the piston. All of the parts above described may be of conventional construction.

My invention consists in providing a gas holder of the general type above referred to, with one or more vertically-movable, stiff members, of annular or tubular form, arranged vertically in the space between the piston 4 and the side wall 2 ,cf the housing, for causing the sealing element -S to assume a certain approximate shape or form during the rise and fall of the piston, and reinforce said sealing element and absorb forces exerted on said sealing element by the pressure in the storage chamber. In the preferred form of my invention shown in Figures 1, 2, 3 and 4, the apparatus is equipped with only one of such vertically-movable annular members, designated by the reference character A. It is arranged above the sealing element S and is so positioned that the horizontal bottom edge of said member A is normally engaged or contacted by an annular intermediate portion of the sealing element S, thus in effect dividing said sealing element into an inner portion 8 whose edge is attached to the peripheral portion of the piston,

and an outer portion 9 whose edge is attached to the housing side wall 2. The particular point on the portion of the sealing element S that is engaged by the bottom edge of the member A, is

immaterial, so long as said sealing element and member are arranged in such a relationship that the bottom edge of the member A engages the sealing element at a point intermediate the inner and outer edges of said sealing element. The essential thing is that the member A be arranged above the sealing element S, outside of the gas storage chamber X, and that said member A be mounted and actuated in such a way that during the upward stroke of the piston, said member will form a rigid backing for a substantial area "of the sealing element, and when said sealing element moves with the piston, a portion of the sea-ling element which previously had been backed up by the outer side of said member A will be progressively stripped oil the same and progressively applied to the side wall 2 of the housing of the apparatus, and a portion of the sealing element, which previously had not been backed up by the member A, will be progressively applied to the inner side of said member. In the apparatus herein shown, the piston 4 is provided at its peripheral edge with a back stop member for the sealing element S, formed by a rigid, vertically-disposed, annular rim B that projects upwardly from the piston. In certain positions of the piston, the pressure in the storage chamber of the apparatus, presses the inner portion 8 of the sealing element 8 snugly against said back stop B. As previously explained, that portion of the side wall 2 of the housing located above the point where the outer edge of the sealing element S is attached to said side wall, constitutes a back stop against which the outer portion 9 of th sealing element is pressed by the pressure in the storage chamber.

As previously explained, the vertically-movable member A is of substantially cylindrical shape in general form or outline, and it has sufficient stiffness or rigidity to withstand the forces exerted on same by the flexible sealing element S. Said member A is herein illustrated as being formed by two or more stiff, circular members 6, capable of taking compression, joined together by vertically-disposed, slat-like members 5 that also act as posts or struts which hold the compression members 6 in spaced relation. The posts or struts may be spaced apart circumferentially from six inches to eighteen inches, depending upon the pressure thrown by the gas holder. The back stop member B on the piston may also be of "similar construction, and it is herein shown as being rigidly connected to the piston 4 by brackets I. As previously explained, if only one verticallymovable member A is employed, the back stop B on the piston is about one-half the height or depth of the member A.

- Various means can be used to support the vertically-movable member A in the annular space between the piston and the side wall 2 of the housing, and to cause said member to move with the piston during a portion of the upward stroke of the piston. In the gas holder shown in the drawings, the member A is suspended from chains Ill attached to the side wall or to some other suitable portion of the housing, and said member is provided at its top edge with a plurality of horizontally-disposed arms i i, proportioned and arranged so that during the upward stroke of the piston 4, the top edge of the-back stop major portion of the inner part 8 of the dry-seal B is pressed against the back stop member 13 on the piston by the pressure in the annular space between the peripheral portion of the piston and the side wall of the storage chamber, as shown in Figure 2. The pressure in said amlular space also forces the major portion of the outer part 9 of the dry-seal S against the outer face or side of the member A. Accordingly, the back stop B on the piston and the vertically-movable member A coact with each other to produce a backing and reinforcing structure that absorbs forces exerted on the dry-seal S, and causes the unsupported portions of said seal to assume the shape or form of upwardly-disposed loops of relatively small radius, which have sufficient strength to resist the stresses set up in the flexible material of which the seal S is constructed. The member A is heavy enough to cause it to remain stationary in the position shown in Figure 3 dur ing the first portion of the upward stroke of the piston, and during this movement of the piston, the inner part 8 of the sealing element S is progressively stripped oli of the back stop 33 on the piston and progressively applied to the inner face of the vertically-movable member A, with the result that the sealing element is wrapped around the member A. At this stage or the cycle of operations, the member A prevents the outer part 9 of the sealing element from flexing inwardly, towards the piston, and also prevents the inner part 8 of the sealing element from flexing outwardly, towards the side wall of the storage chamber. As the piston continues to move upwardly, the back stop member B on the piston, engages the horizontally-disposed arms I! on the member A, with the resui that the member A moves upwardly with the piston at the same speed as the piston, thereby causing the outer part 9 of the sealing element S to be progressively stripped oi? the member A and progressively applied to the back stop portion of the side wall of the housing, as shown in Figure 4. Figure 4 shows the piston at the end of its upward stroke. In this position of the piston, the part 8 of the sealing element is pressed outwardly against the inner face of the member A, and the part 9 of the sealing element is pressed outwardly against the side wall of the housing, the sealing element S being so proportioned that there is still a small upwardly-disposed loop at the upper end of same which can readily resist the pressure in the storage chamber of the apparatus. Another inherent feature of the structure herein shown, is that parts of the sealing element S, when the piston is in its lowermost position, assume a looped form or shape, even though the weight of the inner and outer portions of said sealing element is greater than the upward pressure exerted on the looped portions of the sealing element by the medium confined in the annular space between the piston an'd the side wall of the housing. This feature accomplished by the fact that the parts 8 and 9 'of the sealing element are held pressed tightly against rigid back steps or abutment members, and the friction between said members and the sealing element is a great deal more than the amount of force required to keep the sealing element S from slipping downwardly, due to its own weight. Therefore, it is assured that the sealing element S will always be in the positions shown in the drawings, and lying flat against the vertically-movable member A and the co-acting member B on the piston, Without any horizontal wrinkling.

As shown in Figure 4-, the height or depth of the back stop B on the piston limits or controls the distance that the piston can move upwardly towards the roof 3 of the housing. The vertically-movable member A which constitutes the main control for the dry seal S in no way limits or restricts the upward movement of the piston, due to the fact that said member A is so mounted and operated that during the upward stroke of the piston, the member A becomes disposed in telescoped relation, with the back stop member B on the piston. Accordingly, one desirable feature of my invention is that itconsiderably reduces the overall height of gas holders of the type that are equipped with a dry-seal and with a structure for controlling the shape or form of said seal and reinforcing the same during the cycle of operations of the piston.

While I prefer to equip the piston of the apparatus with a back stop B of substantial depth or height that is adapted to co-act with a single vertically-movable, tubular member A located in the annular space between the piston and the housing side wall, I wish it to be understood that my broad idea contemplates the use of a plurality of such vertically-movable members, arranged in concentric relation, and combined with each other and with the piston in such a way that during the upward stroke of the piston, they assume positions in diiferent horizontal planes, and thus form an adequate pressure-absorbing means for the flexible sealing element, even though the piston is provided with only a relatively shallow back stop rim or no back stop at all for the sealing element.

Figures 5 and 6 of the drawings illustrate a gas holder of the construction just referred to, the additional verticaliy-movable backing and reinforcing member being designated by the reference character A. Said addition-a1 member A is disposed in the space between the verticallymovable member A, and the side wall 2 of the housing, and it is so mounted that when the piston is at the end of it downward stroke, as shown in Figure 5, the member A will lie in a different horizontal plane than the member A, and the member A will lie in a different horizontal plane than the member B on the piston. After the piston reaches a certain point in its upward stroke, it picks up the member A which then starts to rise with the piston, and subsequently when the piston reaches such a point that the top edge of the member A comes into engagement with the inwardly-projecting, horizontally-disposed arms I l on the member A, said member A will start to move upwardly with the piston. Thus, it will be seen that when the piston reaches the end of its upward stroke, the three elements that constitute the control means for the piston sealing element, to wit, the back stop B on the piston and the two vertically-movable members A and A, are arranged in telescoped relationship.

From the foregoing it will be seen that one of the outstanding advantages of my invention is that it enables the height of the side wall of a gas holder to be materially reduced. Bearing in mind the facts (a) that such side walls often have a height in excess of 100 feet; and (b) that the highest portion of the side wall is always the most expensive part to build, it will be apparent that my invention effects a considerable saving in the cost of gas holders of the dry-seal type. Stated specifically, my invention provides a reliable control for the flexible piston sealing element, by increasing the height of the side wall of the housing only one-sixth of the total rise of the piston, when the apparatus is equipped with one vertically-movable backing and reinforcing member that is substantially twice the height or depth of the back stop member on the piston. When two vertically-movable backing and reinforcing members are employed, as shown in Figures and 6, the member 3 on the piston is pref erably made one-half the height of th intermediate, vertically-movable member A, and said intermediate vertically-movabl member is preferably made one-half the height of the outer vertically-movable member A, which gives the result that the only extra height required in the side wall of the housing to accommodate the height of the back stop member on the piston, becomes one-fourteenth of the total rise of the piston. In order to make the foregoing clear, I have shown in Figures 1, 2 and 3, that th total rise of the piston is 24 feet, that the height or depth of the back stop member B on the piston is 4 feet, that the height or depth of the vertically-movable member A is 8 feet, and that when the piston is in its uppermost position, as shown in Figure 4, the extra height that must be added to the side wall 2 of the housing to accommodate both the vertically-movable back stop member and the back stop member on the piston is only 4 feet. Similarly, in Figures 5 and 6, I have shown that if the total rise of the piston is 140 feet, and the members B, A and A have depths of 10 feet, 20 feet, and 40 feet, respectively, the extra height that must be added to the side wall of the housing is only 10 feet.

To recapitulate, some of the distinguishing characteristics of my improved dry-seal gas holder are as follows:

(a) The piston-sealing means consists of a single, flexible, curtain-like element attached at 10 its inner edge to the piston and attached at its outer edge to the side wall of the housing;

(b) The vertically-movable back and reinforcing member or members that co-act with the piston sealing element are arranged above said element, outside of the gas storage space of the apparatus;

(c) The said vertically-movable member or members are not gas-holding or gas-conflning elements, and hence, can be made in the form of a skeleton-like structure;

(at) The said vertically-movable member or members and the back stop member on the piston are so arranged and operated, that when the piston is at the end of its downward stroke, said parts are disposed in different horizontal planes, in concentric relation, and during the upward stroke of the piston, said parts move into telescoped relation; and

(e) The vertically-movable member or members and the back stop on the piston, comprise annular compression members, that effectively control the shape and movement of the flexible piston sealing element, resulting from the pressure which the gases in the storage chamber exert on said piston sealing element.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A gas holder, comprising a casing provided with a side wall, a floating, vertically-movable piston in said casing that forms the top wall of the gas storage space of the apparatus, a flexible sealing element circumferentially attached to the peripheral portion of the-piston and to an intermediate portion of thecasing side wall and made of such length as to provide for the vertical travel of the piston within the casing, a reinforcing structure for said sealing element comprising a plurality of substantially rigid, cylindrical-shaped sections arranged in telescopic relation, the section having the smallest diameter being rigidly attached to the piston and projecting upwardly from the top side of same and one of said sections being disposed between the piston and the casing side wall and mounted so as to be capable of vertical movement relatively to the previously mentioned section attached to the piston, and means for mounting and actuating the said vertically-movable section that is disposed between the piston and the casing side wall, so that when the piston is at the end of its downward travel, a portion of the sealing element is pressed against said vertically-movable section by the pressure of the gases in the storage space and during part of the upward travel of the piston the portion of the sealing element previously contacted by said vertically-movable section is progressively stripped off of said section and applied to the casing side wall.

2. A gas holder of the kind described inclaim l, in which said vertically-movable section remains at rest during a portion of the upward travel of the piston, said. gas holder also comprising means for causing said vertically-movable section to move with the piston during a portion of the upward travel of the piston.

3. A gas holder of the kind described in claim 1, in which said vertically-movable section is at rest when the piston starts to move on its upward stroke said gas holder also comprising means for causing said vertically-movable section to start to move vertically with the piston at a certain point in the upward travel of the piston, whereby a change is effected in the relative position of the vertically-movable section and REFERENCES .CITED the section attached to the piston, during the The following references are of record e upward stroke of the piston. me of this patent:

4. A gas holder of the kind described in claim l, in which the means for actuating the verti- 5 UNITED STATES PATENTS caliy-movable section of the reinforcing struc- Number Name Date ture, comprises parts at the upper end of said 2, 108538 Wiggins Oct. 1, 1946 section, disposed in overhanging relation with the piston and adapted to be engaged by a part on FOREIGN PATENTS the piston, so as to cause said vertically-movable 10 Number Country Date section to move vertically with the piston, 4,790 Great Britain of 1823 JOHN W. ALLEN.