US2187917A - Water heater - Google Patents

Description

Jan. 23, 1940. s. R. SKINNER ETAL WATER HEATER Filed Nov. 25, 193B 1 ea j/ydrem hit Patented Jan. 23, 1940 WATER HEATER Benjamin B. Skinner and Lee Andrews, Denver, 0010.

Application November 25, 1938, Serial No. 242,131

.4 Claims. (01. 122-44) This invention relates to improvements 7 in water heaters of the gas burning type designed for use with the ordinary range boilers.

It is the object of this invention to produce a water heater of the general type shown in United States Letters Patent Ito/1,107,548 of August 18, 1914, but which shall embody several novel features of construction.

Another object is to produce a heater in which the heat is applied uniformly over any desired portion of the outer surface of the tank from the bottom to the top so as to produce in the tank a rapid circulation of the water and by means of which the heat produced by the combustion will be absorbed as completely as possible.

Another object is to provide a heating device that is heavily insulated whereby only a comparatively small amount of heat. is dissipated through the heater wall and in which the hot gases of combustion are maintained in close con tact with the surface of the tank during its passage to the flue. i

A further object is to provide a heater having its inner surface curved to a shape that a com- The above and other objects which may become apparent as the description proceeds are attained by means of a construction and an arrangement of parts that will no-w'be described in detail, and for this purpose reference will be had to the accompanying drawing in which the invention has been illustrated in its preferred form, and in which: s

Figure l is a diametrical, vertical section taken on line l-l, Figure 2;

Figure la is a fragmentary section showing a slightly modified form of insulating member;

Figure 2 is a transverse section takenon line 2-2, Figure 1;

Figure 3 is a view of the concave side of the insulating member, portions being broken away to decrease the length;

Figure 4 is a section taken on line 4-4, Fig. 1, and shows a detail of the construction;

Figure 5 is a top plan View of a pan which forms the bottom of the casing;

Figure 6 is a section taken on line li t, Fig. 5; Figure '7 is a section taken on line 'l--'I, Fig. 1;

Figure 8 is a top plan view of the burner; and Figure 9 is a section taken on line 9--9, Fig. 1. In the drawing reference numeral [0 designates a tank of the type normally referred to t as range boilers and reference numeral l l represents a metal housing in which the tank is 1 electro-welded to the wall of the tank and isprovided with a central sump. l3 from which a drain pipe l4 leads to a valve 15. of the tank is provided with connectors 16 and I1 which are respectively connected with the cold and the hot water supply. Pipe 16 has a downward extension Hia that serves to deliver the cold water near the bottom of the tank. Attached to the walls of easing II near the top are transverse bars it that are heldin place by rivets and these are interconnected by means of transverse bars It in the manner shown in Fig. 9. A band 20 surrounds the tank near its upper end and is clamped in position by means of bolts 2|. Secured to the band 20 are upwardly extending bars 22 whose ends are bent into the form of hooks, which embracethe upper edges of bars l8 and IS. The boiler is therefore supported from the bars l8; and I9 and its weight is carried by the casing H.

Referring now more particularly to Figs. 2 and 3, it will be seen that one-half of the circumierenceof the boiler is surrounded by a semicylindrical member of refractory material which has been designated by reference numeral 23. This refractory member is formed from fireclay or some similar heat resisting and heat insulating material. The insulating member extends the entire length of the tank as shown in Figs. 1 and la and has its edges bent inwardly. in the manner indicated by reference numeral 24 so as to contact'the sides of the tank. at diametrically opposed positions. secured to the tank bymeans of two or more straps 25, whose ends are secured together by bolts 26 in the manner shown in Fig. 2.

It willbe seen that the inner surface of the insulating member is spaced from the outer surface of the tank somedi'stance so as to form a combustion chamber. It is therefore necessary to provide some spacing members that hold the insulating material in properly spaced relation to the tank. It will also be observed from an inspection of Figure 1 that the distance from the outside surface of the tank to the inner surface of the insulating material is somewhat greater near the bottom than near the top, and that The upper end 40. The insulating member 23 is these areas of different radii are connected by means of an inclined surface 21. Projecting inwardly from the surface below breast or shoulder 2'! are a plurality of refractory plugs 28 of such length that they contact with the surface of the tank and the remainder of the area is provided with a plurality of highly refractory pins 29 that do not contact with the surface of the tank, but terminate in close proximity thereto. The inner surface of the insulating member above the inclined shoulder 27 is provided with a plurality of triangular projections 30, whose vertices project downwardly in the manner shown in Fig. 3. These projections are staggered so that the gases of combustion will travel in a zigzag line as indicated by the arrows in Fig, 3. Some of the projections are provided with projections 3| of smaller area that project beyond the surface and engage the outside wall of the tank so as to position the latter with respect to the insulating member. The majority of the projections 30 are out of contact with the surface so that they will not transmit any heat from the tank outwardly after the gas has been turned off, as they might otherwise do.

The pins 29 are made of very refractory material that will become redhot when the burner is in operation and this serves both to produce complete combustion of the gas and to convert the heat into a radiant heat that will continue to be delivered to the water in the tank after the gas has been turned off.

In Fig. 1 the depth of the space between the tank and the insulating member has been shown as somewhat less above the breast or inclined Well 21, than below the same, but this is not an essential feature and it is contemplated to make the insulating material 23 of the same thickness throughout its length as shown in Fig. 1a. The

presence of the pins 29 and the projections 30 assure that the heat in the gases will be delivered to the tank even though the space is the same from top to bottom.

During manufacture the insulating member 23 a is attached to the tank by means of straps 25 as already explained and the assembly is inserted into the casing from the top and properly centered therein.

The casing is provided with a bottom member i 32 which is formed from sheet metal and secured to the tank by means of rivets 33. This bottom has openings corresponding to the tank and to the space required for the burner 34. After the tank has been inserted and straps 22 hooked around the transverse supporting bars I! and IS, the spaces between the tank and the casing wall and between the insulating member and the casing wall are filled by some inert heat insulating material 35, which is preferably exfoliated vermiculite. but instead of this insulating material, rock wool or asbestos may be employed. The vermiculite is believed to be superior for the reason that it will not attack the metal, it is light, and cheap and will not be affected by high temperatures in the manner of rock wool, which will fuse if heated beyond a certain temperature. The lower edge of the refractory heat insulating member 23 is bevelled in the manner indicated in Figs. 1 and 1a. and designated by reference numeral 36, this gives room for the upper edge of the burner 34. Burner 34 is preferably semicircular in the manner shown in Fig. 8 and the gas is delivered to it through a pipe 31. A heat responsive thermostatic member 38 projects into the interior of the boiler and controls a gas valve 39 in the manner common with automatic water heaters. A by-pass 40 provides gas for a pilot burner, all in the usual manner. P- sitioned beneath the burner is a pan 41 whose corners are cut away as indicated at 42 and this rests on the diagonal angle bars 43. The pan is spaced from the flange 44 the thickness of the lower flanges of angles 43, so that air may freely pass upwardly through the spaces designated by reference numeral 45 and between the edges of the pan and the upper surfaces of angles 43. Pan 4! is provided with upwardly extending flanges 46 to give it rigidity. The casing I l is supported on short legs 41 so as to provide air spaces 48 through which air may enter for use in the combustion. The casing is provided with an opening that permits inspection and adjustments to be made of the burner and of the discharge valve. but this has not been shown for the reason that it is positioned in the side that has been removed.

In the drawing the casing H has been shown as rectangular, but it may be of any other suitable shape, such as circular or octagonal, the rectangular construction, however, appears to be the most desirable.

It is obvious from the above description. when taken in connection with the drawing that this method of heating water insures that practically all the heat present in the gas is transmitted to the water because of the great length and width of the combustion chamber. The radiant pins 29 and the projections 30 serve to deflect the gas and to somewhat retard its upward movement. thereby giving it time to transfer its heat to the water before it finally leaves through the flue 49. The burner is so constructed that it gives a wide thin flame which is properly mixed with air so as to give complete combustion and this produces an intense heat that causes radiant pins 29 to glow. The gases are caused to travel in zigzag lines as shown in Fig, 3 and ample opportunity and time is given to effect a proper heat transfer. In the construction shown, the heat is applied on one side of the tank, which causes the water adjacent this heated surface to travel upwardly. while it travels downwardly on the opposite side of the tank. This produces a rapid circulation of water that prevents the formation of the calcareous deposits adjacent the bottom in the manner inherent in water heaters of this type where the heat is applied directly to the bottom of the tank. The fact that the interior of the heater remains fairly free from calcareous deposits assures a more rapid heat transfer than would otherwise be possible, and this in turn gives a greater thermal efficiency.

Having described the invention what is claimed as new is:

1. In combination with a hot water tank, an elongated concave-convex member of refractory material of substantially the same length as the tank, the concave surface having a radius of curvature somewhat greater than that of the outer surface of the tank, the edges of said member having inwardly projecting ribs for engagement with the outer surface of the tank. the concave surface being provided with a plurality of spaced projections for engaging the surface of the tank to form spacers and for effecting a heat conductive connection between the tank and the member of refractory material. the inner surface of the refractory member being also provided with a plurality of refractory pins in longitudinally staggered relation for deflecting heated gases of combustion and absorbing heat which is I surface facing the outer surface of the tank, the

, concave surface of the member having a plurality of staggered projections contacting the tank to space the parts and to transmit heat thereto by conduction, and other projections that are somewhat shorter than the spacers and are longitudinally staggered, means for attaching the member to the tank whereby a transversely concave-convex combustion chamber is formed, a heater element in the lower end of the combustion chamber and a vent flue in communication with the upper end of the combustion chamber.,

3. A hot water heater comprising a metal housing whose smallest dimension is greater than the diameter of the tank, supporting bars extending transversely of the housing near its top, a tank positioned in the housing, a clamping band attached to the tank near its upper end, hooks attached to the band for engagement with the supporting bars to suspend the tank therefrom, a member of refractory material positioned'within the housing, and means for spacingthe inner surface of the refractory member from the tank to form a combustion chamber.

4. A hot Water heater comprising a metal housing whose smallest dimension is greater than the diameter of the tank, supporting bars extending transversely of the housing near its top, a tank positioned in the housing, a clamping band attached to the tank near its upper end, hooks attached to the band for engagement with the supporting bars to suspend the tank therefrom, a member of refractory material positioned within the housing, means for spacing the inner, surface of the refractory member from the tank to form a combustion chamber, a plate attached to the inside of the housing and extending inwardly into contact with the bottom of the tank to forma bottom for the space between the housing and the tank to support a filling of heat insulating material. I

BENJAMIN R. SKINNER. LEE ANDREWS.

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