US2619955A - Flat tank water heater - Google Patents

Description

Dec- 2, 1952 w. G. CARTTER 2,619,955

FLAT TANK WATER HEATER Filed Aug. 7, 194s 2 SHEETS- SHEET 1 4? Arma/Ens.

Dec. 2, 1952 w. G. cARTTl-:R 2,619,955

FLAT TANK WATER HEATER f5' f l 'i z" I 5; f5

a af 7 ia j W w f INVENTOR.-

32 WML/AM c. cA/PTTER Patented Dec. 2, 1952 FLAT TANK WATER HEATER William G. Cartter, Monrovia,

Calif., assignor,

by mesneassignments, to Affiliated Gas Equipment, Inc., Delaware Cleveland, Ohio, a corporation of Application August 7, 1948, Serial No. 43,037

p Claims. 1

The invention relates to water heaters and more particularly to water heaters of a type which is adapted to handle hot water in relatively large volumes utilizing burners supplied preferably with gas as a fuel.

Modern heating of hot water demands that the water be heated relatively quickly when the need for hot water arises, without the necessity of providing a reservoir of hot water of any appreciable volume. The tendency is more and more in the nature of heaters so arranged that water as it is drawn through the heater from the source of supply at a moderate rate can be heated sufficiently to supply the need. Among the problems encountered in the heating of water by such devices is the necessity for carefully shielding the water from all contacts with the iiue gases. Another is the necessity of eliminating condensate in the form of moisture which condenses out of the combustion gases and which is prone to collect on interior surfaces of the heater.

Even where gas as a fuel is relatively inexpensive it is highly desirable to avoid waste of heat generated by the burning gas which readily occurs when heaters are not properly insulated or when vents, pipes or other vehicles for the passage of water through the heater are not so designed that they provide substantially a maximum of contact of the water carrying vehicles with high temperature ilu gases. Moreover, water heaters heretofore devised wherein the vehicles for the retention and ow of water have been completely enclosed have given considerable difficulty because of sedimentation in the water passages after a period of time, which condition has been extremely aggravated in certain localities where the water supply has been particularly heavy with hard water and mineral substances.

It is therefore among the objects of the invention to provide a new and improved water heater adapted to the utilization of gaseous fuel which is more eiiicient than water heaters heretofore employed and in which is embodied a maximum degree of safety by reason of the fact that the heater is so constructed that there can be no accumulation of gas pressure within those portions of the heater containing the water to be heated.

Another object of the invention is to provide a new and improved water heater whereiny water is induced to iiow from one stage to anotherfollowing a circuitous path which provides substantially a maximum contact between the portions of the heater containing the flowing water and the portions in direct contact with the heated products of combustion.

Still another object of the invention is to provide a new and improved water heater of a style ordinarily designated as a flat tank water heater wherein water is enabledv to pass from one tank to another by gravity flow and in which the tanks may be readily removed for cleaning and inspection and at the same time may be opened so as to make possible the thorough cleaning of both the interior and the exterior of the tanks.

A further object of the invention is to provide a new and improved at tank water heater featuring individual tanks for the gravity flow ci water while in the process of being heated, the tanks of which are so constructed that they can be opened for inspection and cleaning and which when closed provide suitable traps around conduits respectively for the fiow of flue gases and the flow of water to effectively prevent infiltration of moisture and condensate from the products of combustion into the heated water.

Still further among the objects of the invention is to provide a flat tank water heater wherein trays are so arranged and constructed that condensate is prevented from dripping downwardly into the area of the burners and which is further provided with trays so constructed that not only can the trays be readily removed but also so constructed that trays may be interchanged `and on occasions increased in number for the furnishing of housings of larger size in order that a heater of greater capacity may be constructed by use of standard parts.

With these and other objects in view, the invention consists in the construction, arrangement and combination of the various parts of the device whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a vertical sectional view of the heater taken on the line I-I of Figure 3.

Figure 2 is a fragmentary vertical sectional view drawn to a larger scale and illustrating the portion of the device where hot water is drawn off.

Figure 3 is a cross-sectional View of the device taken on the line 33 of Figure 1.

Figure 4 is a fragmentary cross-sectional view taken on the line 4 4 of Figure 2.

Figure 5 is a fragmentary vertical sectional view taken on the line 5 5 in a direction at right angles to the view illustrated in Figure .1 and showing the condition of the device lwhen water is flowing therethrough.

In the embodiment chosen for the purpose of illustration there is provided a heater hereto-l fore referred to as a flat tank water heater adapted to be contained within a housing indicated generally by the reference` character Hl supported upon a base indicated `by the char-r acter I I, the heater being supplied from a supply pipe I2 and being adapted to have hot water drawn therefrom through outlet pipes I3. A series of gas burners I4 fed from a gas main l5 provides heat for the device, the housing being shown as provided with a vent l5 for spent flue gases at the top of the housing.

The base in the embodimentJ shown includes footings in the nature of channels 2G adapted to support a sheet metal frame comprising walls 2l, an open bottom 22 and a plate 23 providing access to a chamber 24. Within the chamber there is located a conventional thermostat control valve adapted to feed fuel gas from the main l5 into a pressure regulator 25 from which the gas passes through a connection Z1 to a manifold 28 from which the burners lli are fed. A base 29 may be provided for the support of the manifold.

The housing i0, as illustrated, is a double walled structure having outer plates Sil, inner plates 3l and a heat insulating material 32 therebetween. If preferred and as illustrated the housing may be constructed of separate side walls 53, 5A and 35 the inner and outer plates of which are bolted together at the corners as is more particularly illustrated in Figure 3. A wall of similar construction is adapted to be removably secured at the corners to adjoining walls 33 and 34 by means of bolts 31. A top 5S also constructed of outer and inner walls retaining therebetween a heat insulating material is shown secured in position upon the tops of the walls 53, 34 and 55. The vent I6 is illustrated as being located centrally with respect to the top.

At the bottom of the housing there is provided a condensate pan Ml located beneath the burners and providing around its outer edge passages if for the admission of air into a combustion chamber 42 and a passage 43 through which the connection 21 extends. Below the condensate pan is a temperature shield 65 the edges of which extend outwardly beyond the passages 5l. Any condensate falling through the combustion chamber is thereby collected upon the condensate pan which becomes relatively hot while the burners are burning and is consequently more readily vaporized leaving the temperature shield fill dry and clean at all times.

Above the combustion chamber l2 is mounted a series of trays 50, 5| and 52, three in number in the particular embodiment selected. As here shown angle brackets 53 and 54 are illustrated together with a Z bar 55 for the purpose of supporting the lower-most tray 55. Tray 5l is supported by the tray and tray 52 by the tray 5 l.

Tray 55, being the lowermost tray, is provided with spuds 56 adapted to be coupled to the outlet pipes I3 in each of which may be located a Valve 51. For reception of the spuds there are provided lined openings 53 in the wall 35 of the housing and a sealing device 59 on the outside surface of the wall for effectively sealing the aperture when the spud is in place.

In general the trays 50, 5l and 52 are quite similar with respect to structural features to the extent that a detailed description of one will be a suicient guide to the construction of the others. The tray 50, for example, includes a bottom having a central flat horizontal portion and a peripheral well 10 formed by downwardly sloping portions 1|, horizontal portions 12 and peripheral wall portions 13, the peripheral wall portions being considerably higher than the portions 1l. A top or cover 14 is provided for the tray having a flange 15 adapted to overlie the top edges of the peripheral walls 13. As is readily apparent in Figures 1 and 2 the top or cover 1d 4 is somewhat dished to theextent that a sloping portion 16 permits the portion 14 to lie in a horizontal plane lower than the top edges of the side walls 13.

Scattered about the bottom 55 of the tray 5S are a series of flue apertures or passages 11 adapted for the passage of products of combustion generated in the combustion chamber 42. These passages comprise tubular pipes 18 the bottom edges of which may be welded along the line 19 to flanged edges of the bottom 59. A liquid tight seal is thus provided at the junction of the pipe with the bottom 59.

The top 14, as perhaps more readily apparent in Figure 2, is provided with a series of double crimped, upwardly extending rims or flanges 8i, each flange 8| forming an annular recess on the under side of the top or cover 14 circumjacent the nue aperture 11. Into this recess fits the top edge of the flue pipe 18. Each flange 5l constitutes a dam preventing condensate on the top 1li from draining down through the aperture 11. The juncture between the flue pipe 15 and the top 14 is thus made without any packing or sealing means, thereby permitting the ready removal of the top for cleaning and inspection purposes. A loose fit is provided between the pipes 18 and the channel shaped rims so that the top 14 may be readily lifted from its position over the bottom when occasion requires.

In the tray 5i), unlike the other trays, there is provided a weir 82 adjacent the outlet the form of which may best be seen in Figure 4. The weir 82 provides a separate draw-off chamber or well from which water passes outwardly through the pipes i3.

In the tray 5i which exemplies also the tray 52 there is provided in the bottom 69 aweir which in effect forms a means for passing water from one tray downwardly to the next tray below. The weir is formed by providing a pipe 83 which is welded along the line 84 to the rim of an annular flange 85 in the bottom 69. The top edge of the pipe 83 is located a substantial distance above the bottom 59 so that in effect it forms a standpipe or weir and establishes the depth of water in the tray 5l under conditions of no iiow or in other words at a static water level.

The pipe 83 extends downwardly a distance beyond the bottom of the tray 5I so thatit is adapted to extend into the tray next below by provision of an aperture 36 in the top or cover 1li of the tray 55, for example. A sliding fit is preferable so that the tray 5l may be set upon the tray 50 supported at its outer edges at which time the pipe 83 extends through the top 14 down into the interior of the lower tray. A skirt 81 is preferably provided secured to the outer surface of the pipe 83 and adapted to overlie the turned up edge or flange formed around the aperture 85, thereby providing a deflection and dam preventing any condensate accumulating on the underside of the bottom 59 from passing into the water contained in the tray 55. Only one pipe S3 need be provided in the tray 5i and no more than a single pipe S3 need be provided in the tray 52. The pipes 83 and 83', however, are preferably located on sides of the trays opposite one from another. The flue pipes 18 on the other hand may be more numerous as indicated by the circles both dotted and solid in Figure 3, the flue pipes of the lower tray in each instance being staggered with relation to the fiue pipes in the tray next above thereby providing a circuitous passage for the hot flue gases between the burners I4 and the vent I6.

In order further to improve the rate of contact of Water in the trays with the sides and bottoms of the trays which are heated by the flue gases, a baille may be interposed in each one of the trays Ell, 5l and 52. In the tray 52, for example, a top View or which may be seen in Figure 3, the baille Si! extends outwardly from a wall 9i terminating in an edge 92 spaced some distance from a wall 93 thereby providing space between the edge 92 and the wall 93 through which water may iiow. Similarly there may be provided a baille 94 in the tray 5l and a baiile 95 in the tray 5l), these being devoted to the same purpose as the baii'ie 99. The top edge of the balile in each instance is illustrated as being located substantially below the top of the tray but also at a substantial distance above the top of the Weir located in the tray bottom. The top of the baiile should furthermore be located above the moving water level, indicated at 9S in Figure 2. The static level, at the top of the pipe 83, is indicated at 9S.

In the uppermost tray there may be provided a camstat 9E, and in the lowermost tray a conventional thermostat 9'! which may be used for oper-ating the thermostat control valve 25 when connected thereto in the usual way.

In operation let it be assumed that water has already been admitted to the heater but that no call is being made for hot water from the heater and that the burners are unlighted. This will be the condition illustrated in Figure l. Water will lie in each of the trays 50, 5I and 52 to a depth in the case of tray 5l! level with the top of the Weir 82 and in the trays 5l and 52, respectively, level with the tops of weirs formed by I the upper edges of the pipes 83 and d3', respectively. A substantial quantity of water will be carried in the peripheral wells at the sides of each of the trays.

Assuming now that additional water is admitted through the inlet pipe I2, the uppermost tray 52 will have its level raised somewhat in order that the water level in the tray may overl'low the top edge of the pipe 83'. In practice the level of the liquid in tray 52 when the water is flowing may be as much as one and one-half t two times the depth of the liquid in the tray under static conditions. This is more or less the increase in level ordinarily experienced in order to have the liquid overflow into the pipe 83. It should be noted in this connection also that the inlet pipe l2 is on one side of the baie Si! whereas the pipe 83 is on the other side of the baille necessitating horizontal movement of the water in the tray 52 before it flows downwardly by gravity into the tray l. Again in the tray 5i the location at which water from the pipe 83 enters the tray is on one side of the baille 95, whereas the pipe 83, by means of which water leaves tray 5|, is on the other side of the baille 94. Under conditions of flow the liquid level in the tray 5l will also be raised an appreciable amount but not, however, sufficient to overflow the baille 94.. Yet again liquid or water passing downwardly through the pipe 8S falls into the tray 5i! on one side of the baille 95 and leaves the tray 55 by overflowing the weir 32 into the well 'Ill on the other side of the balile 95. A very Yappreciable increased dow or movement of liquid in the trays is thus made certain thereby greatly improving the eiciency in the trays. This is essential particularly when water is drawn the top of the tray next below.

oi at a relatively rapid rate from the heater and needs to be heated very rapidly during its flow.

The pipes 'I8 forming the flue passages through the tray 50 are scattered or staggered with relation to the pipes 18 forming flue passages to the tray 5l. Again in the tray 52 pipes T8 are staggered with relation to the pipes 'I8' but for convenience may be more or less in -alignment with the pipes T8 of the tray 5U. In the event that iiow should be shut off, a substantial amount of water remains in the trays and particularly Water gathered in the peripheral wells. The reservoir of water thus provided remains heated and the condition may be described as a flywheel effect in that there is a carry-over supply of hot water between periods of activity.

When condensate forms by reasons of moisture condensing out of the iiue gases on the outer surfaces of the trays such condensate if not picked up and carried off through the vent is apt to gravitate toward the bottom of the housing. Accumulation of condensate is minimized by providing the covers with the dished shape herein described. Condensate may collect in the dished covers of the trays where it may remain temporarily but in a new heating cycle there will be suiiicient heat to Warm up the cove-rs to a temperature capable of evaporating the condensate and thereby carry it off through the vent l E. At the same time the condensate is prevented from passing into the Water within the trays by action of the traps around the loose-fitting portions of the pipes 83 and 83 and also the pipes 18, 18' and 78".

After heaters of this kind have been in use for a considerable period it frequently becomes advisable to clean the trays both outside and in. When this becomes necessary the removable side 36 of the housing may be removed and al1 of the trays slid out of the casing along and over the supports 54 and 55. Once outside of the housing the tray 52 may be lifted from the tray 5l, the pipe 83 being capable of being lifted clear of This is possible because the pipe has only a sliding lit into the top of the tray next below. The same arrangement applies with relation to the pipe 83 of the tray 5| when it is desired to lift the tray 5| from the tray 50.

Having separated the trays one from another, the top of each tray may be lifted clear of the side walls and clear of the flue pipe in the respective tray. Both the insides and outsides of the trays may be cleaned and renovated and the trays and covers thereafter put back together for reinsertion into the housing. Because of this arrangement any trays or covers which have become damaged or rendered unfit for further service may be replaced by corresponding new parts without the necessity of replacing an entire set of trays. Although a set of three trays is shown, it will be appreciated that should trays be used of lesser depth more trays might be used thereby changing to some extent the characteristics of the heater. On the other hand, trays of greater depth might be used in the same manner, or the same trays used in greater number in a housing of greater height.

In providing a flat tank water heater having the structural characteristics just described a very serviceable heater is provided, a heater having flexible characteristics with respect to heating capacity and iiow capacity is made possible and the entire structure is one made readily serviced, thereby greatly increasing the overall operative efficiency over long periods of service.

While I have herein shown and described'my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope o the claims so as to embrace any and all equivalent devices.

Having described my invention, what I claim as new and desire to secure by Letters Patent is: 1. In a flat tank water heater comprising a vented housing, a base comprising a support for the housing and gas burning means in the base, the combination of: a plurality of covered vertically stacked trays for holding and for passing water through said housing, and a tray support in the housing, each tray comprising a bottom having a central flat area, a peripheral well depressed below the central area, and side walls adapted to provide support for the tray bottom next above, and a removable downwardly dished cover overlying the side walls, the bottoms of said trays having each a series of scattered flues extending upwardly through the respective cover, and a condensate dam tted removably around the top of each flue, a tubular weir in each bottom except that of the lowermost tray extending through the cover of the tray next below, and f a condensate dam independent of the iirst mentioned condensate dams circumjacent each tubular weir at its junction with said last named tray cover, the uppermost and lowermost of said trays having laterally extending liquid conduits, and means forming openings in the housing through which said conduits pass.

2. A flat tank water heater comprising a plurality of vertically stacked trays and covers therefor engaging side walls of the trays, each such tray having a well portion extending around and below the central bottom portion and adapted to be supported by the tray next below, each said cover comprising a downwardly dished central portion, the perimeter of each cover resting on the top of the wall of the corresponding tray, ilue pipes in each tray bottom open therethrough, at least one water pipe extending through and downwardly from each tray bottom except that of the lowermost tray, each of said covers having aperture means therein for reception respectively of said water and flue pipes, upwardly extending anges around the aperture means for the water pipes engaging portions of said water pipes, and upwardly extending flanges around said aperture means for the flue pipes engaging portions of said flue pipes, both said flanges forming respective liquid dams for condensate on the top of said covers.

3. A at tank water heater comprising a plurality of vertically stacked trays and covers therefor engaging side walls of the trays, each such tray having a well portion extending around and below the central bottom portion and adapted to be supported by the tray next below, each said cover comprising a downwardly dished central portion, the perimeter of each cover resting on the top of the wall of the corresponding tray, ilue pipes on each tray bottom open therethrough and extending upwardly through said cover, and at least one water pipe in each tray bottom except that of the lowermost tray extending downwardly from the tray bottom, said cover having ape tures corresponding to said flue and water pipes, an upwardly extending flange around the water pipe aperture, and a double crimped, upwardly extending flange around the flue pipe aperture forming an annular recess on the under side of the cover around the iiue pipe aperture into which fits the upper end of the ue pipe, both of said flanges constituting liquid dams preventing condensate on the top of said cover from flowing down through said apertures.

4. In a at tank water heater comprising a housing vented at the top and gas burning means in the base of the housing, the combination of: a plurality of covered, vertically stacked trays for holding and for passing water downwardly through said housing, flue means for passing hot gases upwardly past said trays from said gas burning means to the vented top portion of the housing, at least one of said trays having a tubular Weir extending through the bott-0in of said last named tray and downwardly to communicate with the tray next below, the cover of said tray next below having an aperture receiving said weir, an upturned flange on said cover around said aperture forming a liquid dam to prevent condensate from draining through the aperture into said tray next below, and a downturned flange on said weir extending over said upturned flange to direct condensate onto said cover.

5. In a flat tank water heater comprising a vented housing, a base comprising a support for the housing and gas burning means in the base, the combination of: a plurality of covered vertically stacked trays for holding and for passing water through said housing, and a tray support in the housing, each tray comprising a bottom having a central iiat area, a peripheral well depressed below the central area, and side walls adapted to provide support for the tray bottom next above and a removable downwardly dished cover overlying the side walls, the bottoms of said trays having each a series of scattered iiues extending upwardly through the respective cover, and a condensate dam iitted removably around the top of each flue, a tubular weir in each bottorn except that of the lowermost tray extending through the cover of the tray next below, and a condensate dam independent of the rst mentioned condensate dams circurnjacent each tubular Weir at its junction with said last named tray cover, the uppermost and lowermost of said trays being provided with liquid conduits extending to the exterior o1 said housing.

WILLIAM G. CARTIER.

REFERENCES @FEED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 585,244 riurner et al. June 29, 1897 868,085 Goodrich Oct. 15, 1907 1,441,899 'Walling Jan. 9, 1923 1,529,732 Willsea Mar. 17, 1925 1,628,107 Braach May 19, 1927 1,809,920 Woodward June 16, 1931 1,854,858 Nissen Apr. 19, 1932 1,925,299 Brown Sept. 5, 1933 2,250,900 Alexander July 29, 1941 2,401,988 Tribuson June 11, 1946 2,568,948 Cartter Sept. 25, 1951 FOREIGN PATENTS Number Country Date 201 Australia Sept. 25, 1899 216,362 Great Britain May 29, 1924 288,849 Great Britain Apr. 19, 1928

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