US2331857A - Boiler - Google Patents

Description

Oct. 12, 1943. E. F. CHANDLER BOILER File d Feb. 17, 1940 3 Sheets-Sheet 1 v INVENTOR.

BY M 9 A TTORNEYS.

Oct. 12, 1943. E. F.,CHANDLER BOILER s s'n eets-shee t 2 Filed Feb. 17, 1940 INVENTOR- ATTORNEYS.

Oct. 12; 1943. E. F. CHANDLER BOILER Filed Feb. 17, 1940 :s Sheets-Sheet s Fla.

E I kl? IN V EN TOR. Q ,1: Mn. $64

BYOZMQZM A TTORNEYS.

Patented Got. 12, 1943 BOILER Edward F. chandlen Brooklyn Y assignor to J 01m P. Chandler, as trustee- Applicati onFeliruary 17, 19M semi l lo. 31 9;3 1

9- Claims.

This invention relates to heating systems and more particularly to generators or boilers of the steam, hot water or vapor type employed in heat and air conditioning systems. It is an object of the invention to provide a small, compact unit of relatively great heating capacity that is light in weight and inexpensive to manufacture. It" is an object to provide a unique type of boiler or generator that is effioient and rapid in operation and economical to run. The results obtained aredue' to'the novel operating principleemployed and the means evolved for carrying the method'into'praetice.

The foregoing and other objects of the inven tion will be best understood from the following description of the exemplificatins thereof shown in the accompanying drawings, in which Fig. 1' is a front elevation of a boiler or generator section;

Fig. 2 is a side elevation of two'sect'ions-joined together, one of which is insection;

Fig. 3 is a front elevation of a boiler cover-- plate for closing one end of the boiler, equipped with indirect water heating means;

Fig. 4 isa sideelevation of Fig. 3;

Fig. 5 is a front elevation of a boiler cover plate for closing the other end of the boiler;

Fig. 6 is a side elevation of Fig. 5:

Fig. 7' isa top view of Fig. 5; v

Fig. 8 is a side elevation of a complete boiler of a, modified design;

Fig. 9 is afront elevation of Fig. 8;

Fig. 10 is a side elevation of asix section assembly of a castironboiler;

Fig. 11 illustrates diagrammatically a usual type cfboiler and indicates the direction of water cir culation under steaming conditions; and- Fig. 12 illustrates diagrammatically a boiler constructed in accordance with the inventiveidea herein disclosed and indicates the direction of Water circulation under steamingconditions; 7

Referring to Fig. 1 2 is an inlet port and 3* is an outlet port. The inlet 2 communicates-with the'pocket 4-which is connected by means of't'ubular ducts 5, 6, 7' and if with the hollow leg 9 andthe water space lB-of'the boiler section. The circular opening H affords communication be= tween the several boiler sections employed. The circular'openings'l and H on'the front and'back of each section are preferably machined to re ceive suitable push-nipples l2 and Why means of which, in a well known-manner, said sections may be assembled; side by side, in water'ari'dsteam tight relationship. Preferably each section" is 'provided'wit'ha rim M by means'o'f'wlii'ch-when' the section'sareassembledtlie'b'oiler'will be" clos d on the two" sides and top; to prevent the escape of combustion gases. when theater-red numter of sectionshave" b enput together and pressed" home until theress mp les formtig'ht' joints; the cover-plate It; s own in Fig: 3 may be as; sembled eaten-pie end oftlie group ofsectionsarid" tldecover-plate' rr shown Fig: 5' onto the other end.

Both o the end cover pla'tes are provided with suitable lugs l8 which are drilled to" accommodate tie' rods fonholding the complete boiler assembly together; From the above it will be seen that the assembled. boiler is open only' at thebottom' so that when it isplaced above a suitable combus' ti'on ch'alflbert'and fired; theliot combustion products must upwardly between the boiler sections giving; do its heat to thetubes and to the wall v of the waterspace'l'il} on" their way to the gas outlet openings; l9 which communicate with the stack opening; 2*0 carried by cover plate" IT. The gases ar thus caused to be" divided into a plurality of streams which" scrub the stream-line" tube surfacesand the" relatively-narrow water ockets in" each section; effectively giviligu'ptheii heat before esca ing to' the stacki Obviously; tlietube arid boilefsurf'ace 's" may beprovi'ded with suitable fins to increase the heat absorbing area and, if desired, tocontrol the direction offl'ow'ati'd turbulenceof thegases: v

The cover'plate I6"sh'owif in Figs. 3 and 4, provided with a circular" recess 22* to r'eceive' th'e ress-maple of the adjacent boiler section" and to forma'head foi-tlie'ldoiler watersee'tion'. Boss zspr'ovicres a place to mount an aquaistat another instrument, which may communicate with. the interior of" the boiler. Th boss" 2's s'erveto mount a suitable staclirelay whi'cli is pror' ided with aheat; responsive element adapted to pro ject into-'space l-9- of the sections andito be fluenced: by the heat of the gases, in a wellknownmanner... Qnthe face of I 6- 1SSh0WlL-fl' suitablepocket 25 provided-with a'c'over plate 26 having an inlet H and an outlet 2-3 ofthe continuous,'.dou ble spiralcoiLOf tubinE, oarried'thereby 'and;- adapted t0 serve as an indirect Water heater. Communication-1 betweenthe boiler Water s'paceand the interior of 254s ro'videdrby theopening and toprovidecirculationof hot water" from the" boiler 1 the" pocket 2%; a duct 31 between thespace in= 2 5 and the-inlet closing boSs-3-2, is provided? Boss-$2 is adapted to re ceive a pusli nipple on theiinner side"and is-closed externally. A suitable sight opening as; covered by the swing door 34, for observing the flame, may be provided.

The end cover plate I! conveys waste gases escaping from the openings 19 of the boiler sections thru the openings 36 which communicate with the stack outlet 20, said gases passing around the circular cover element 31 which is adapted to receive the push-nipple 'of the adjacent boiler section. The boss 35 is preferably tapped for the return or inlet Water connection and on the inner side is adapted to receive the push-nipple carried by the inlet boss having the part 2. A suitable covered hand-hole 39 may be provided. ihe boiler as thus far described is designed to be constructed of cast iron. Substantially the same principle of operation however may be employed in a boiler designed to be fabricated from sheet steel or other metal. Made from cast metal the parts are simple to make, light in weight and inexpensive.

Boilers of the type set forth herein are well adapted for heating systems in the operation of which fluid generated by the boiler, steam or hot water, is conveyed by a pipe from the outlet 3 to one or more radiators or convectors, the condensed steam or cooled Water being returned thereafter by a pipe which is connected to the inlet 2 thus providing a substantially closed cycle. Usually such systems are automatically operated under the control of suitable instruments so as to maintain a substantially uniform heating condition, said instruments governing the operation of the fuel burner to supply more or less heat in response to the demands from the space being heated.

The operation of the boiler when being used as a hot water generator is substantially as follows. Referring to the section shown in Fig. 1, cool water entering at 2 fills the pocket 4, flows thru the tubes 5, 6, 'I and 8 into the leg 9 then up into the boiler space and out thru an opening 3 in one of the several sections, the openings 3 in the other sections being closed by suitable plugs. Upon initiating combustion in a suitable fire chamber situated below the boiler, the water in the ducts 5, 6, I, and 8 is progressively heated from a higher to a lower temperature as the combustion gases travel upward toward the outlet openings IS.

The water entering the ducts from the space 4 will be at a substantially uniform temperature but as the heat from the combustion source is delivered to the duct walls substantially uniformly thruout their lengths the water flowing unidirectionally therethru will be heated cumulatively. The water in the duct 5, situated directly in the radiant heat zone of the furnace, absorbs the greatest amount of heat. heated water from duct 5 blends with the less highly heated water from the ducts above so that the water in the space I0 represents a mean temperature and issues from the outlet 3 at a predetermined temperature as governed by an aquastat in well known manner. It will be noted that all water entering at 2 mustpass thru the direct heating zone in order to reach the outlet 3 which eliminates short-circuiting the boiler by the incoming cool water. directly into the leg 9 while duct 8 connects with space I!) thru the opening 8'.

As previously mentioned the normal flow of fluid entering at 2 is from the space 4 thru all of the ducts to the opposite side of the boiler section, but when operated as a steam generator at different set of conditions obtains. For ex- The highly' Tube ducts 5, 6 and 1 lead,

ample, assuming that as a steam boiler a suitable water level is established which provides ample space above for the release of the vapors generated, the highly heated water, particularly from duct 5, will rapidly ascend in the space 9 to the surface of the water in the boiler to give up its vapor, the extension 3 of the inner wall of the leg 9 tending to guide the direction of flow. To complete the circulation, the cooler water in the lower part of the boiler space it! is drawn thru the opening 8' into duct 8 and back to the space 4 for re-passage, in the opposite direction, thru the lower tubes and again is subjected to the elevated temperature of the heating zone.

By eliminating direct communication between the water in the inlet leg 5 and the boiler water, thus causing a relatively small volume of water in the ducts to expose a relatively great surface to the active heat transmitting area of said ducts, the circulation of the water is greatly augmented and very rapid steam generation is obtained. By causing the hot combustion gases to envelope both surfaces of each boiler section heat is transmitted to both the water and the steam spaces of each boiler section, which fact may be taken advantage of in the design of the boiler to superheat or otherwise modify the temperature of the steam being generated.

It will be noted that the boiler, whether used as a hot water or steam generator, operates on the contraflow principle, the hottest water being delivered by the ducts closest to the source of heat, said ducts being supplied by water from the coolest part of the boiler thus maintaining a wide temperature difference between the boiler terminals. Also, the internal resistance to flow is small, which is particularly important when operating the boiler as a hot water generator.

Referring to Figs. 8 and 9, a boiler fabricated from sheet metal, welded steel plate for example, embodying the invention is shown in which the boiler 40 is provided with a water leg at on one side and a water chamber 42 on the other side. A plurality of tubes 43 connect the parts 4! and 42. Preferably, flat tubes of the type shown in Fig. 8 are employed which present a relatively great heat receiving surface in relation to the volume of water they contain. They also serve to guide the furnace gases in a zig-zag path thru the unit. Round or other shape tubes may be employed without departing from the spirit of the invention. The size and number of tubes in each case will depend upon the capacity and conditions to be met. As shown in Fig. 8, the fiat tubes 43 are preferably staggered so as to afford a path fOr the furnace gases which ultimately escape thru the stack opening 46.

Operated as ahotwater generator, feed or return water enters the inlet 44 and the space 42 and flows thru the tubes as a thin, flat stream to the leg 4| and into the boiler proper and issues from the outlet 45. The boiler being mounted over a combustion chamber the lower tube is subject to the direct racliant heat of the furnace and the water therein is rapidly heated to a high temperature and discharged into spac M where it blends with the less highly heated water being delivered simultaneously by the other tubes. An aquastat 49 controlling the source of heat may be employed to govern the temperatur of the Water issuing from the outlet 45. 50 indicates the preferred position of a standard stack relay,

an element of the usual control system for antomatic heating apparatus. Cover plates 41 and .48 may be used to close the front and rear of the boiler. In Fig. 9 the front late 4"! i re' moved. An indirect coil (not shown) may be inserted thru the boiler shell at a point where the coil will be submerged in the heated water, for supplying domestic hot water.

When this boiler is used as a steam generator a suitable water level is established, as may be indicated by well known means (not shown). Then when heat is applied, circulation of the heated water in the lower tubes will be from space 42 to the water leg 4| where the highly heated water ascends in the outer part of the leg 4! to the boiler space. The cooler water from the lower part of the boiler space follows the inner wall of the leg 4! and is drawn into the upper tubes and travels in the opposite direction to that in the lower tubes due to the violent circulation induced therein by the heat energy input from the furnace. In this manner active circulation of the relatively small volume of water in the tubes is established with an accelerated generation of steam.

Experience has shown that this method of operation increases the efiiciency and capacity over boilers of the usual design in which, in place of the space 52, a water leg in direct communication with the boiler water is employed. Also, by this method a greater temperature difference is maintained within the prime heat absorbing system. Boilers designed in accordance with the invention herein disclosed afford high fuel economy because they absorb a maximum of radiant heat. The radiant heat passes directly from the incandescent heat source to the boiler without affectin-g the temperature of the intervening gas and is absorbed by the heating surface with practically 100% efficiency. As is well known, the greater the amount of heat so transmitted, the less the amount which enters the gases, hence the lower the furnace temperature will be. A practical advantage of the present invention, it may be noted, is the uniformly high efficiency which obtains over long periods of operation and which is due to the fact that the absorption of radiant heat by the system is not diminished by the accumulation of soot on th heating surfaces, as is the case where performance depends largely on surfaces heated by convection. Also, the principle of operation employed favors relatively high rates of heat transfer.

Because of the relatively large volume of water which must pass thru the device in a iven time, when operating as a water heater, low internal resistance to flow is important. By providing a plurality of paths, dividing the body of water and passing it simultaneously thru said paths, the desired low resistance is afforded, and the reduction in velocity of travel which results prolongs the period of heat absorption. By this means together with the other features small, light weight, inexpensive boiler is afforded equaling in capacity and performance the larger, more bulky and expensive boilers now in use.

Circulation is augmented by the increased temperature differential and by the kinetic energy of the absorbed heat. While auxiliary means may be employed to further augment thermal-Syphon action, such means are not required to initiate, maintain or control the direction of circulation. Research conducted to determine the characteristics favoring high thermal capacity, mechanical simplicity, low construction cost, efficiency and small size led to the discovery of the novel principle of operation and the simple means of carrying the principle into effect. By maintaining a wide temperature difference in the system, heat absorption is rapid and complete and waste heat in the stack gases is reduced to a minimum.

In Fig. 11 is illustrated diagrammatically a boiler of the usual design. It will be noted from the arrows indicating the direction of circulation that as the flow is accelerated the entire body of water contained in the boiler will gradually assume a substantially even temperature. The water heated in the tubes or ducts passes up thru the boiler, down on the other side and back thru the tubes or ducts in a continuous circuit thereby narrowing the temperature clifference between it and the source of heat, thus reducing the rate of heat to the water and limiting the capacity of the boiler. It is obviously desirable to maintain a relatively high rate of heat transfer in order to derive the greatest eifi ciency and economy.

In Fig. 12 is illustrated diagrammatically a boiler constructed in accordance with the present invention. From an examination of the flow'of water therein, as indicated by the arrows, it will be noted that the highly heated water from the lower tubes or ducts which are nearest to'the source of heat flows to the upper part of the boiler, the cooler water returning along the bot-- tom surface of the boiler to be drawn into the upper tubes due to the impulse or flow accele'rat ing action of the lower tubes and then into the lower tubes or ducts, where this relatively cool water is again subjected to the direct heat of the furnace. In this manner a relatively wide temperature difference is obtained between the water in the lower tubes or ducts and the furnace and a greatly increased absorptionof heat by the water is obtained as indicated by a reduction of the temperature of the escaping combustion gases. This method of operation makes possible a boiler for a given heating capacity that is small, compact, light in weight, efficient and inexpensive to manufacture.

The principles of invention disclosed herein will suggest many modifications thereof to those skilled in the art, and it is accordingly desired that the appended claims be given a broad construction commensurate with the scope of the in- Vention.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments described, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. A water heater comprising a horizontal water chamber, a first water leg extending downwardly from one side of the chamber and connected thereto at its upper end, a second water leg extending downwardly from the other side of the chamber and separated at its upper end from the chamber, a vertical series of heating tubes connecting the legs and arranged for location over a source of heat, a water inlet at the bottom of the second leg and an outlet for heated fluid at the upper part of the chamber.

2. A Water heater as set forth in claim 1 including a return passage for cooler water connected at one end to the chamber and at the other end to the second water leg.

3. A water heater as set forth in claim 1 including a substantially horizontal return passage for cooled water connected at one end to the chamber and at the other end to the second water leg, the lower heating tubes sloping upward- 1y from the second water leg to the first water leg.

4. A water heater as set forth in claim 1 in which the tubes are progressively smaller from the bottom to the top of the series, arranged to produce substantially higher temperatures in water passing through the lower tubes.

5. A water heater as set forth in claim 1 in which a plurality of the tubes are vertically alined and arranged in close proximity to each other, said tubes being substantially stream lined in vertical cross section and arranged to provide smooth successive side wall contours presenting reduced resistance to the smooth flow of heated gases upwardly along the sides of successive tubes.

6. A water heater comprising a horizontal water chamber of substantial size, a first water leg extending downwardly from one side of the chamber and in direct communication therewith, a second water leg extending downwardly from the other side of the chamber and separated at its upper end from the chamber, a water inlet at the bottom of the second leg, a vertical series of water heating tubes connecting the legs, the lower tubes being arranged for direct heating by a source of heat below the heater to provide a flow of heated water from the second leg to the first leg, the upper tubes being located in a lower heat zone with at least one tube arranged to provide a return flow of cooler water from the bottom of the chamber to the upper part of the second leg.

7. A water heater comprising a horizontal water chamber, a vertical series of generally horizontal water heating tubes located beneath the chamber, a first vertical leg connecting the tubes at one end with one side of the chamber, a second vertical leg connecting the tubes at the other end with a water supply, a water return passage having an inlet connected to the chamber adjacent the first leg and discharging into the second leg, and bafile means for diverting from said inlet, water flowing from the first leg into the chamber.

8. A sectional water heater comprising a plurality of sections each provided with a water chamber at the top, a first water leg at one side directly communicating with the chamber, a second water leg at the other side separated from the chamber and a vertical series of heating tubes connecting the legs; a centrally located passage connecting the chambers of adjacent sections; an inlet passage connecting the lower ends of the second legs of the sections; flue passages in the upper parts of the sections at either side of the passage connecting the chambers; and end plates including means for holding the sections in assembled position.

9. A water heater comprising a water heating system including a plurality of water heating tubes and means connecting registering ends of said tubes to provide a water circulating system having an inlet passage; and an auxiliary water heater comprising a hot water compartment and an auxiliary water heating unit located in the compartment, said compartment having a restricted connection with the water circulating system adjacent the inlet passage and a spaced restricted connection with said system substantially above the first connection, arranged to provide circulation of water through the compartment.

EDWARD F. CHANDLER.

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