BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally relates to a device for releasably sealing a row of cartridge filters within a dust collector, such as a bag house filter assembly. In particular, the present invention relates to a moveable support structure for cartridge filters. When placed in a first position, the support structure maintains a row of filters in sealing engagement within the dust collector. Movement of the support structure to a second position causes the row of filters to be suspended in a non-sealing relationship with the collector assembly to permit easy removal of the filters.

Description of the Related Art

A common type of filter assembly used to clean air during industrial operations generally comprises a housing which is separated into upper and lower chambers by a partition, commonly called a tubesheet. In general, the tubesheet is a panel in which multiple rows of apertures are formed. Cylindrical cartridge filter elements are suspended below the tubesheet in such a manner that each aperture in the tubesheet has a corresponding filter suspended below it in a sealing relationship with the tubesheet about the periphery of the aperture. Particularly, a cartridge filter element generally comprises a cartridge filter having a flange secured to its upper end having a sealing gasket thereon. The sealing gasket is interposed between the flange, about the upper rim of each cartridge filter, and the lower peripheral edge of each aperture in the tubesheet when the filters are sealed within the filter assembly.

During operation of the filter assembly, dust laden air is routed into the lower chamber. The dust and other particulate contaminants in the air are deposited on the filters, and the filtered air is routed upwardly through the interior of the filters and into the upper chamber through the tubesheet apertures. The clean air can then be utilized for various purposes.

To clean the filters, powerful air pulses are periodically forced downwardly into the filters in a direction opposite the flow of air during filtration. This causes the dust which has become caked onto the filter during filtration to be discharged from the surface of the filter. Some of this dust is re-entrained into the flow of air being filtrated. However, a large quantity of the dust falls downwardly into a bin or hopper at the bottom of the lower chamber. The dust, thusly collected, can be easily removed.

Over time, the cartridge filters lose their effectiveness and the filters are required to be replaced. Removing the sealed filters has traditionally been a cumbersome and dirty process. In many filter assemblies, each filter is mechanically engaged within the housing on an individual basis. Replacing the filters accordingly requires that each filter be individually disengaged from the tubesheet and removed from the housing. Since the filter assembly must be shut down during replacement of the filters, this cumbersome replacement process results in the equipment to which the filter is attached to be shut down for excessive periods of time, thereby reducing the efficiency of the subject industrial operations. Additionally, workers charged with changing these filters are forced to enter the lower chamber of the filter assembly where they come in close proximity and even direct contact with the dust. In addition to this being highly unpleasant, the dust may contain harmful toxic contaminants. Accordingly, changing cartridge filters has

been and continues to be problematic, unpleasant, and perhaps dangerous.

U.S. Pat. No. 4,322,231 discloses a mechanism which purports to solve some of the foregoing drawbacks. The mechanism permits releasably mounting an entire row of cartridge filters in sealing engagement within the filter assembly. Particularly, the patent discloses a mechanism having a pair of parallel bars, with one bar extending lengthwise on each side of the row of filters. Each bar has a flat surface upon which the filters can be slid for removal. In addition, each bar has a curvilinear surface. When the bars are rotated, the curvilinear surfaces act as cams and force the row of filters upwardly into sealing engagement within the filter assembly.

To rotate the bars for engaging the filters, a handle attached to the end of each bar must be rotated to substantially an overlapping horizontal, or closed, position with respect to the other handle. Such an operation requires inconvenient movement by a worker within the close confines of the space available for accessing conventional filter chambers. Moreover, the locking handles are held in overlapping relationship by support brackets on the handles to prevent them from rotating back to an open position. As a result, the handles are constantly subject to forces attempting to rotate them back into an open position and the device is greatly dependant on the stability of the support brackets on the handles.

In view of the foregoing, it is desirable to provide a mechanism for releasably mounting a row of cartridge filters within a filter assembly which makes it convenient to replace filters and which is well-adapted to resist any undesirable forces attempting to release filters from their sealed engagement within the filter assembly.

SUMMARY OF THE INVENTION

The present invention comprises a locking device for releasably engaging a row of cartridge filters in sealing engagement with the tubesheet within a filter assembly.

The preferred embodiment of the locking device of the present invention comprises both an upper beam and a lower beam suspended in brackets along each side of the row of filters at a location near the top of the filters and just beneath the tubesheet. The flange located at the top of each cartridge filter rests on a portion of the upper beam. The upper and lower beams slidingly engage each other. Predetermined periodic valleys and plateaus are formed in the terrain of these engaging edges. Preferably, the lower edge of each upper beam is formed with a plurality of periodically spaced downwardly extending projections. The upper edge of each lower beam is formed with a plurality of cut-away portions, or valleys. It should be understood that the lower edge of the upper beam could have cut-away portions while the upper edge of the lower beam comprises upwardly extending projections.

When each upper and lower locking beam is in a first location with respect to the other, the downwardly spaced projections of each upper beam rest in the cut-away portions, or valleys, of the upper edge of its associated lower beam. In this location, the flanges of the filters, which rest on a portion of the upper beams, are downwardly displaced from the bottom of the tubesheet. As a result, filters resting on the beams can be easily removed by sliding them out of the filter assembly along a portion of the upper beam upon which they rest. New filters can similarly be slid into the filter assembly. Sufficient movement of at least one of the beams longitudinally in relation to the other causes the projections of the upper beam to be removed from the valleys and to become engaged with the plateaus of the lower beam. Preferably, handle

bars mounted to each lower beam are rotated inwardly along a path which is in the same longitudinal plane as the lower beam, thereby causing the lower beam to move to a location where its uppermost portions are beneath the downwardly extending projections of the upper beam. As a result, the upper beam is forced upwardly so that filters resting on the upper beam, by their respective flanges, are engaged in a sealing arrangement with the tubesheet, and namely, the periphery of the apertures of the tubesheet.

In another embodiment of the present invention, each upper beam is moveable in relation to its respective lower beam, which may be either moveable or stationary. In yet another embodiment, only one beam is provided along each side of the row of filters. Each beam has notches, or cut-out portions, along its lower edge. The upper edge of each beam is substantially flat. Horizontal longitudinal movement of each beam causes the lower edge of the beam to slidingly engage support brackets in which the beam is suspended. The beam is vertically displaced in response to the variation in the terrain of the lower edge thereof, thereby permitting movement of the filter elements, which rest on a portion of the beams, between a sealed and non-sealed relationship with the tubesheet.

It is accordingly an object of the present invention to provide a locking device for locking a row of filters in sealing engagement within a filter assembly.

It is an object of the present invention to provide a device which facilitates the easy removal and replacement of filters from filter assemblies.

It is also an object of the present invention to provide a locking device for releasably sealing a row of suspended filters within a filter assembly which is convenient to use and economical to manufacture.

It is yet another object of the present invention to provide a device adapted to releasably seal a row of filters suspended within a filter assembly with the filter assembly by substantially horizontal movement of at least one bar of a pair of bars located along each side of the row of filters.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the invention noted above are explained in more detail with reference to the drawings, in which like reference numerals denote like elements, and in which:

Fig. 1 is a top plan view of a portion of the tubesheet and filter assembly of the type generally used in conjunction with the present invention, with the view having portions broken-away to show the arrangement of cartridge filters suspended beneath the tubesheet, and with broken-line portions showing the flanges of cartridge filters beneath the tubesheet;

Fig. 2 is a left end view taken along lines 2-2 of Fig. 1 and showing the access area to a chamber of cartridge filters;

Fig. 3 is a side-elevational view taken along lines 3-3 of Fig. 2 showing the locking device of the present invention positioned along one side of a row of cartridge filters for releasably sealing the filters within the filter assembly;

Fig. 4 is a side-elevational view showing the locking device of the present invention positioned along one side of a row of cartridge filters for permitting removal of the filters;

Fig. 5 is a cross-sectional view taken along line 5-5 of Fig. 2.

Fig. 6 is a cross-sectional view taken along line 6-6 of Fig. 5.

DETAILED DESCRIPTION OF THE INVENTION

With reference to Fig. 1, a portion of a tubesheet denoted by the reference numeral 10 is shown. As discussed above, the filter assembly of the type generally used in conjunction with the present invention comprises a housing separated into an upper and lower chamber by a partition, such as tubesheet 10. The tubesheet includes apertures 12 located in rows on the sheet. During operation of the filter assembly, filters are suspended in sealing engagement with the bottom-side of tubesheet 10, and particularly, each aperture 12 has an associated filter 14 suspended beneath it and sealed about the periphery of the aperture. Each filter 14 has an associated flange 16. Since the general operation of a filter assembly of the type described herein is set forth above and will be readily appreciated by those skilled in this art, the housing and upper and lower chambers of the filter assembly have not been shown in detail.

Referring now to Figs. 2 - 4, the locking device of the present invention, generally denoted by the reference numeral 20, is described. Locking device 20 releasably engages a row of individual filters 14 in a sealed relationship with tubesheet 10, and particularly, permits substantially simultaneous sealing of each filter 14 in a row of filters with the periphery of an associated aperture 12 in tubesheet 10. Front and rear walls of the housing of the filter assembly are shown schematically in dashed lines by reference numerals 11 and 13, respectively. A door 15 for accessing the lower chamber of the filter assembly is similarly shown in dashed lines. As shown in Fig. 2, the preferred embodiment of locking device 20 is comprised of a pair of individual locking bar mechanisms, with one mechanism located on each side of a row of filters 14. It

will be understood that the mechanisms are used cooperatively to engage the filters 14 in a sealing manner within the filter assembly. Rotating handlebar 36 from an outwardly extending position to a substantially vertical position forces a row of filters 14 upwardly into sealing engagement with tubesheet 10. A sealing gasket 52 located on top of each flange 16 creates a seal when it is depressed between the flange 16 and tubesheet 10.

With reference to Fig. 3, one side of a row of filters 14 is shown. Suspended beneath tubesheet 10 by a plurality of brackets 26 are a lower beam 22 and an upper beam 24 (partially hidden) . The lower edge 28 of upper beam 24 has a plurality of periodically spaced downwardly extending projections 30. The upper edge 32 of lower beam 22 has a plurality of periodically spaced cut-out portions 34. Preferably, each cut-out portion 34 has a leading ramp edge 44 and a trailing ramp edge 46. Each leading ramp edge 44 preferably has a more gradual gradient than its respective trailing ramp edge 46. It should be understood that the terrain of the upper edge 32 of lower beam 22, and particularly the cut-out portion 34, can be of various geometric configurations while still accomplishing the purposes of the present invention. Moreover, the number of downwardly extending projections 30 and associated cut-out portions 34 is not critical.

In this regard, opposing beam surfaces may comprise at least one first portion and at least one second portion, whereby the first portion of each beam extends a selected direction to a greater extent than the second portion. Particularly, in such an embodiment, the first portion of the lower edge surface of each upper beam extends downwardly to a greater extent (i.e., depth) than the second portion of the lower edge surface of each upper beam. Similarly, the first portion of the upper edge surface of each lower beam extends upwardly to a greater extent (i.e., height) than the second

portion of the upper edge surface of each lower beam. If multiple first and second portions are provided on each beam, it is preferred that each first portion extend to substantially the same depth or height, whichever the case may be, and similarly, each second portion of each beam extend to substantially the same depth or height, which ever the case may be, as all other second portions on the same beam. It will be understood that engagement between an upper and lower beam at their first portions, as defined, will upwardly displace the upper beam thereby locking each filter 14 in sealed relationship about its associated aperture 12 in tubesheet 10. By contrast, engagement between an upper beam 24 and lower beam 22 at the first portions(s) of one beam and the second portion(s) of the other beam, as defined, will downwardly displace the upper beam thereby dropping the filter elements 14 so they can be slidingly removed from the filter housing.

However, it is preferred that there be one downwardly- extending projection 30, and accordingly a respective cut¬ out portion 34, associated with and aligned with each filter 14. As shown in Fig. 3, each downwardly extending projection 30 is preferably located adjacent a central location of its respective filter 14 when the locking device 20 is positioned for sealing the filters 14 with tubesheet 10. Such an arrangement lends stability to locking device 20. It should also be understood that each lower beam 22 could have upwardly extending projections adapted to engage with cut-out portions and non cut-out portions of upper beam 24, for positioning the row of filters out of an into sealing engagement, respectively.

A handle bar 36, having a plate 37, is pivotally mounted to stationary support beam 38 by pin connection 39. The plate is further attached to lower beam 22 at a location near the end of beam 22. It will be understood that such attachment may be made using various known mechanical methods or

devices, such as screws, bolts, rivets, welding, or a combination of these or other methods and devices. For instance, as shown, a bolt 40 may be secured through a hole in plate 137 and a downwardly opening mouth portion 42 located near the end of lower beam 22, thereby mechanically securing beam 22 to plate 37. Other means of securing beam 22 to plate 37 may be employed.

When handle 36 is positioned in substantially the vertical position shown in Fig. 3, downwardly extending projections 30 of upper beam 24 rest on associated uppermost portions 33 of upper edge 32 of lower beam 22. In this position, it should be understood that the forces between upper beam 24 and lower beam 22 are substantially vertical. Brackets 26 resist the downward force while tubesheet 10 resists the resultant upward force. The dimensions of the upper and lower beams, in combination, are such that sealing gaskets 52 (not shown in Fig. 3) are tightly compressed against tubesheet 10 to form a seal when locking device 20 is positioned as shown in Fig. 3. Particularly, in such a position, each cartridge filter 14 is releasably sealed to its associated aperture 12 on tubesheet 10. It should be understood that because it is preferred that handlebar 36 remains substantially vertical, and hence parallel to the forces required to engage the row of filters 14 in a sealing relationship with tubesheet 10, and further because rotational movement is not required to releasably engage the filters in a sealing manner within the filter assembly, no further means are required to lock handle bar 36 in place.

It should be understood that movement of at least one of upper beam 24 and lower beam 22 in relation to the other does not necessarily require the handlebar mechanism shown. Rather, any sufficient means to force the beams to move in relation to each other are considered to be within the scope of locking device 20 of the present invention. Furthermore, the present invention is preferably designed such that any

inadvertent outward movement of handlebar 36 will be stopped by door 15 prior to any descent of each projection 30 of upper beam 24 into its associated cut-out portion 34 of lower beam 22. Similarly, sufficient inadvertent movement of lower beam 22 in an opposite direction to cause each projection 30 of upper beam 24 to drop into the cut-out portion 34 which proceeds it towards the end of lower beam 22 to which handlebar 36 is attached is prevented by engagement of lip 62 of mouth 42 with bracket 26. Accordingly, even in the unlikely event that inadvertent or undesirable horizontal forces cause horizontal movement of lower beam 22, restraints are provided to prevent movement of a sufficient nature to cause projections 30 to slip into cut-out portions 34 thereby causing disengagement of the seals between filters 14 and tubesheet 10.

In Fig. 4, the door 15 accessing the lower chamber of the filter assembly has been removed and handle 36 has been pulled outwardly, causing it to pivot at pin connection 39. Movement of handle 36 outwardly in such a manner causes lower beam 22, which is connected to handle 36 by the arrangement of plate 37 and bolt 40, to move substantially horizontally in the general direction towards handle 36. Upper beam 24 remains substantially horizontally stationary during the horizontal movement of lower beam 22. As handle 36 is pivoted outwardly, downwardly extending projections 30 of upper beam 24 and upper edge 32 of lower beam 22 slidingly engage each other. Particularly, the predetermined periodic spacing of downwardly extending projections 30 and cut-out portions 34 is such that each projection 30 will slidingly engage the leading ramp edge 44 of its associated cut-out portion 34 at substantially the same time during movement of lower beam 22. As will be appreciated, sufficient movement of handle 36 will cause the various cut-out portions 34 of lower beam 22 to be positioned beneath, and therefore mate with, respective projections 30 of upper beam 24, as shown in Fig. 4. It

should be understood that the handlebar 36 attached to the locking mechanism on the opposite side of the row of filters is preferably pivoted outwardly at substantially the same time. Additionally, an axle (not shown) may be positioned between each handle 36, and preferably between each plate 37 at a location at or near pivot pin 39. With such an axle provided, rotational movement of one handle 36 will be transferred through the axle to the other handle 36, thereby allowing the handles to move in unison even in the event unequal forces are applied to each handle 36. Preferably, if an axle is utilized, the beams of the present invention are constructed such that the downward displacement of filter elements 14 from partition 10 will be sufficiently lower than the axle to prevent the axle from inhibiting removal of filter elements 14.

Upper beam 24, although substantially restricted from horizontal movement, is free to move vertically in accordance with the terrain of the upper edge 32 of lower beam 22 and within the limits of the space available. Accordingly, as shown in Fig. 4, upper beam 24 has dropped downwardly. In such a position, as shown in the right-hand row of filters 14 of Fig. 2 and as is described in further detail with reference to Figs. 5 and 6, the filters 14 in the row of filters are downwardly displaced from tubesheet 10, and hence are no longer in a sealing engagement therewith.

As shown in Fig. 5, door 15 has been removed from the lower chamber of the filter assembly. Consistent with the operation described above with reference to Fig. 4, handle 36 has been rotated outwardly about pin connection 39. Lower beam 22 has accordingly moved horizontally in the general direction of handle 36 in response to rotation of handle 36. It is preferred that lower beam 22 remain substantially horizontal during movement. Plate 37 is accordingly geometrically dimensioned to permit

substantially horizontal movement of lower beam 22. Particularly, upward motion of the various points along handlebar 36 as it is rotated outwardly from its substantially vertical beginning position is compensated for at the point of connection between handlebar 36 and lower beam 22 by the geometry of plate 37. More specifically, the generally triangular shape of plate 37 causes the connection point of lower beam 22 and plate 37, namely at the location of bolt 40, to initially move downwardly and outwardly in an arc as plate 37 is pivoted at pin connection 39. This arcwise movement at the location of bolt 40 during pivoting of handle 36 compensates for the upward movement of points along handlebar 36 to maintain lower beam 22 substantially horizontal at all times during movement of lower beam 22.

As seen best in Fig. 6, lower beams 22 are cradled in brackets 26. Each upper beam 24 includes at least two wider portions, shown in dashed lines by reference numeral 54 and located adjacent the brackets 26, for substantially preventing horizontal movement of each upper beam 24. Particularly, wider portions 54 are wider in cross-sectional dimension than the groove in each bracket 26. Each lower beam 22 has a stop member 56 located at its end opposite the end to which handle 36 is connected. Stop member 56 is wider in cross-sectional dimension than lower beam 22 and is also wider than the groove in each bracket 26 in which lower beam 22 is supported. It will be appreciated that outward rotational movement of handle 36, and hence horizontal movement of lower beam 22 in the direction of handle 36, will be accordingly limited by the engagement of stopping member 56 with a bracket 26.

Upper beam 24 has a ledge 50 upon which the flanges 16 of the filters 14 rest. As shown in Fig. 6, ledge 50 consists of an L-shaped member, and an outer portion of the flange 16 of a filter 14 rests on the outwardly extending portion thereof. It should be understood that L-shaped ledge 50

could take on other forms as long as a portion is provided upon which the flanges 16 can rest. In this regard, it should be understood that the present invention contemplates appropriately dimensioning and positioning components such that the flanges 16 rest directly on the upper most edge of upper beam 24.

As shown in Fig. 6, when handle 36 along each side of the row of cartridge filters has been rotated outwardly, downwardly extending projections 30 of each upper beam 24 fall into their associated cut-out portions 34. Corresponding downward movement of each upper beam 24 causes the filters 14 resting thereon to become vertically displaced from tubesheet 10. As a result, each filter 14 can be easily removed from the filter assembly by sliding it out. Removal of successive cartridge filters may be easily accomplished by, for instance, grasping them with a hook and pulling them out. Alternatively, as shown in Fig. 5, the flanges may be interlocked together by mating means 60. In such a case, pulling out the first accessible filter will cause the trailing filters to advance so that the next subsequent filter takes the place of the first filter, and so on. This process may be repeated until all filters are removed, if desired. To replace the filters, an individual filter 14, having been secured to a flange 16, is placed on the ledges 50. The flange of a subsequent filter is then abutted with the flange of the initially placed filter, or perhaps interlocked therewith if interlocking type means 60 are utilized, and the subsequent filter is pushed onto the ledges 50 thereby forcing the initially placed filter further into the filter assembly. This process is repeated as desired until the row of filters is in place. Although the present invention is well adapted to be used with one or more filters, it is primarily used in conjunction with filter assemblies having two to six filters per row.

To produce an effective seal, sealing gaskets 52 are located

on each flange 16 about the central opening of the cartridge filter 14. The use of sealing gaskets is well known in the art. As shown in Fig. 2, each sealing gasket is compressed between the flange 16 and the bottom side of tubesheet 10 when the filters 14 are placed in sealing engagement within the filter assembly.

Locking device 20 permits a row of cartridge filters 14 to be easily releasably retained in sealing engagement within a dust collection filter assembly and further permits easy replacement of the filters 14 when necessary or desired. For instance, replacing filters 14 requires rotating each handlebar 36 outwardly a sufficient distance to cause the cut-out portions 34 of lower beam 24 to be positioned beneath downwardly extending projections 30 of upper beam 24. This operation causes upper beam 22 to drop downwardly, thereby disengaging filters 14 resting thereon (i.e. by their flanges) from their sealing engagement with tubesheet 10. Filters 14 can then be easily removed by sliding them along the ledges 50 of each upper beam 24. New cartridge filters 14 can the be easily inserted into the filter assembly by sliding them along support ledges 50 of each upper beam 24 so that they are aligned in position with the apertures 12 of tubesheet 10. Alignment is made easy by appropriately dimensioning the flanges 16 and the components of locking device 20 and the filter housing such that alignment is present when the filters 14 are slid into the filter assembly along ledges 50 as far as they can be inserted. Rotating each handlebar 36 inwardly to substantially a downwardly extending vertical position causes lower beam 22 to move horizontally inwardly thereby causing downwardly extending projections 30 of upper beam 24 to slidingly engage the upper edge 32 of lower beam 22 such that leading ramp edges 44 of each cut-out portion 34 travels engagingly along its associated downwardly extending projection 30, thereby lifting upper beam 24, until the upper most portions of lower beam 22 engage the projections

30 and the filters 14 are in sealing engagement with tubesheet 10 within the filter assembly.

Those skilled in the art will appreciate that various possible embodiments may be made using the principals of the present invention. For instance, the present invention may be adapted so that each upper beam 24, rather than lower beam 22, is attached to a handlebar 36. In such an embodiment, it will be understood that lower beam 22 is provided with appropriate means to secure it in a substantially stationary position with support brackets 26. As describe above with respect to upper beam 24, lower beam 22 could be provided with various portions located adjacent brackets 26 that are wider than the grooves of brackets 26 for preventing horizontal movement of lower beam 22. It should also be understood that maintaining an upper or lower beam in a substantially stationary horizontal position in accordance with the principles of the present invention could be accomplished by welds, bolts, or other known securing means. Upper beam 24 in such an embodiment is free to move horizontally within certain limits as described hereinabove with respect to lower beam 22. Movement of upper beam 24 in sliding engagement over lower beam 22 will accordingly cause raising and lowering of the filters 14 into and out of sealing engagement with the partition of the filter housing, namely tubesheet 10.

It should be further appreciated that the present invention may be adapted so that both upper beam 24 and lower beam 22 may be moved cooperatively with respect to each other. It will be appreciated that such an embodiment requires more components than are necessary to accomplish the purposes of the present invention, but nevertheless embody the principles herein set forth. Still another variation of a locking device employing the principles of the present invention comprises only a single beam supported in brackets on each side of the row of filters 14. In such an

embodiment, a beam constructed substantially similar to lower beam 22 shown in Figs. 3 and 4 is turned upside down so that the top edge of the beam is substantially flat, while the bottom side of the beam comprises a plurality of notches or cut-out portions. Accordingly, it will be appreciated that outward rotation of a handle mounted to the outwardly extending end of the beam will cause it to move horizontally as herein discussed. However, in this embodiment, the lower edge of the beam will slidingly engage the support brackets thereby causing the beam to raise and lower in accordance with the terrain of the lower edge of the beam. Cartridge filter elements resting on an upper portion of the beam (i.e., on the beam itself or on a ledge attached thereto) will be accordingly raised and lowered into and out of sealing engagement with the tubesheet. It is contemplated that the locking mechanism located on one side of the row of filters could be of one embodiment, while the locking mechanism on the opposite side of the row of filters comprises a different embodiment.

While it is apparent that various embodiments utilizing the principles of the present invention exist, the preferred embodiment described in detail herein permits vertical movement of the beam upon which the filters rest while maintaining the beam in a substantially stationary horizontal position. In this respect, it has been found that more precision of components is required in those embodiments of the present invention which require horizontal movement of the beam upon which the filters rest because, in such embodiments, the filters to be engaged begin vertically misaligned with their corresponding aperture in the tubesheet partition and accordingly must be displaced both horizontally and vertically to effectuate the desired seal.

From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove

set forth together with the other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.