US1786981A - Steam boiler - Google Patents

Description

DecIBO, 1930. 1:, w, CHIPMAN 1,786,981

STEAM BOILER- Filed Julie 15, 1929 2 Sheets-Sheet 1 4 Fig. 1.

7 Fred W. Cha man A'fiys lnvenior,

Dec. 30, 1930. F. w. CHIPMAN 1,736,981

STEAM BOILER Filed June 15. 1929 '2 Sheets-Sheet 2 Fig.2.

lnvemor. Fred W. C hipmun 'Anys.

Y Patented Dec. 30, 1930 FRED W. CHIPMAN, F FRAMINGHAM, MASSACHUSETTS STEAM BOILER Application filed June 15,

This invention relates to boilers for generating steam and has for its general object to provide a boiler which will produce a, maximum yield of steam per square foot of radiating surface.

" The object of the invention is further to provide a boiler in which the natural circu'la-' tion or'convection of water within the boiler is artificially accelerated.

The object of the invention is further to provide 'a means within the boiler connected with the feed water system which will prevent excessive temperatures at the hot areas of theradiating surfaces. v

'15 Theobj'ect of the invention is further to provide a means to distribute the relatively cool feed water rapidly as it enters the boiler over a wide area, I v

o Other objects and featureswill more fully appear from the following description in connection with the accompanying drawings and will be particularly pointed out in the claims. I

. In the drawings:

n Fig. 1 is a longitudinal cross section through the boiler.

Fig. 2'is a transverse section through the front water leg of theboiler showing the feed water system; p

. in order to maintain a l' igh degree of efficiency .a boiler must be so designed that a nice natural flow of water may take place within the boiler from the region of higher temperature tothe regions of lower temper.- at'ure. The rapiditywith which such circulation takes place determines to a large extent the capacity of the boiler to generate steann If a body of Water, for instance, that in contact with the region ofhigh temperature of the.radiatingsurface, becomes heated to the boiling pointv and is retarded in its natural tendency to rise, the proper function'ofthe boiler is greatly impaired. If on the other hand this body of water is moved automatically in some manner cooler water will take its place and a morer'apid heat transference fromthe radiating surfaces to the water will result. If such a relatively rapid circulation is maintained the total volume of water within the boiler is being vaporized at a 1929. Serial m5. 371,285;

greater rate which results in a greater capacity to generatesteam. Furthermore much higherjfire box temperatures may be maintained even to the pointof using high pres sure forced dr'z ught in which case the areas of the .boiler shell'receiving direct contact of the flame from the fire are cooled to a safe-temperature. In other words the rapid circulation of water within the boiler will prevent burning of the hot spots.

The principlesof the inventionfmay be adapted to substantially any type of boiler. The type herein shown is commonly known as a Scotch boiler which is one form of horizontal return tubular construction. In this type of boiler the circulation takes place from the rear thereof which is the hottest region upwardly and then passes forwardly to the'front and thence down. The boiler isgenerallyof standard construction having a main shell 1 having a front plate 52 and a rear plate 3. Within the lower part of the main shell 1 are located fire box shells 4. The number of the shells is immaterial and forms no partof the invention. l/Vithin the shells 4 are grates to support the combustible material in whatever form it isused. It is not essential however that a grate be used since any means of firing the boiler may be employed such as oil or gas. I

Theshells 4 open into the lower end of a combustion chamber 5. The front wall of the combustion chamber forms the rear tube sheet 6while the rear wall thereof is secured to the rear plate 3 in any desirable manner as by stay-bolts 7. Fire tubes 8 are secured at one end in the rear tube sheet 6 and extend horizontally toward the front and are secured in the front plate 2 which consti-, tutesthe front tubev sheet. The products of combustion pass from the fire box through the rear of the firebox shells 4 into the lower portion of the combustion chamber 5 and thence 1 upwardly and into the fire tubes 8 and out the forward end of the boiler to a smoke box9 which leads to a stack not shown.

Above the boiler is located a horizontal steam and water drum 10 which is connected thereto by water legs 11 and 12 located near the front and rear of the boiler. The temperature of the water at the rear of the water to follow the pathabove described. -To

do this the feed water pipe is led into the water drum at the point 13 and extends-forwardly to a. point within the frontwater leg 11 and then vertically :downward to a point within and adjacent to the shell. 1 of the mainboiler. At this point the feed water pipe preferably is led for a short distance in'a substantially horizontal plane at right angles to the longitudinal axis of the boiler.

This may be done by bending the pipe into a horizontal position at its end or the end of thepipe may be fitted with a T 14 which ejects the feed water in opposite directions againstthe cylindrical sides of the main boiler shell.

If desired the T 1e may be fitted with leaders such as sections of pipe 15 which efiectively direct the feed water which is introduced under pressure in ni'ore'definite paths in proximity to the boiler shell.

By leading the feed water pipe downwardly through the front water leg the heat ab-' sorbed by the feed water as it passes through this portion of the pipe lowers the temperature of the water passing downwardly throughsaid water leg and consequently jaccelerat-es the downward circulation thereof. Furthermore the heat thus transmitted to the feed water raises its temperaturebefore it emerges from the feed water pipe into the boiler thereby further increasing the chi ciency of the boiler.

By means of this construction the cooler incoming water is directed down the sides ofthe boiler to a point at the lower cooler iortions thereof. It is desirable however to direct the water flowing downwardly through'through the water leg 11 to the bot- 1 tom of the boiler in a more positive manner.

To do this a chamber or conduit of comparatively small area extends downwardly along both" sides of the main shell 1 and is open at the bottom of the boiler. This chamber or conduit directs the flow of water to alpoint below the fire box. This conduit is formed by partition wall 16 which extends from the front plate 2 rearwardly to a point beyond the water leg 11. The partition wall 16 is brought downwardly a short distance from and parallel to the main shell 1 and is stopped at a point near the bottom of the boiler.

The flow of water downwardly from the leg 11 h'v reason of its contact with the partition wall l6 will be divided and substantially one half the flow will pass down one side and the other half down the other side emerging from the conduit at the cool lower region of the front end of the boiler. As a result of this structure the down flow of the water through the leg 11 is met by a relatively small body of water having a small inertia. The force of the'flow of waterdown the leg 11 thus being confined to this relatively small body of water is able to move it at a rapid rate.

. The present invention is readily adapted to be used in connection with this special conduit construction although it is not confined to use in boilers thus equipped. By means of the specially formed feed water outlets which are located within the conduit the flow of water is greatly accelerated. Both the impact of the'feed water as it is forcibly ejected tubes, a smoke box communicating with the tubes at the front end of the boiler, a horizontal water and steam drum above the boiler, water legs connecting the main shell and the drum at points near the front and rear thereof, a partition wall at the front of the. boiler spaced a short distance from said main cylindrical shell and extending part way of the length of the shell to form a cir culating conduit extending from the front waterleg downwardly along both sides of the main shell and opening at thebottom, a

feed waterpipe having leaders extending in.

opposite directions from its end into said conduit to project the feed Water into the said conduit in directions to accelerate the flow. of water downwardly therein.

2. A tubular boiler comprising a main cylindrical shell having front and rear tube sheets, a firebox, a combustion chamber communicating therewith, fire tubes connecting the tube sheets and communicatingwith said combustion chamber at one end and a stack at their other end, a water and steam drum above the boiler, water legs connecting the boiler shell andidrum, one of said legs being situated adjacent the rear of the boiler to con ductthe rising convection currents and one adjacent the front of the boiler to conduct the downward currents, a partition wall at the front of the boiler spaced a short distance from the cylindricalishell to form a conduit 7 extending from the front water leg downwardly along bothsides of the boiler shell and opening at the bottom, and means to project the feed water downwardly and laterally into said conduit at the upper portion thereof to accelerate the downward currents;

In testimony whereof, I have signed my name to this specification.

FRED W. CHIPMAN.

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