US1839760A - Water tube boiler - Google Patents

Description

INI/ENT@ R' .IF di Jan. 5, 1932. w. D. HoxiE WATER TUBE BDILER Original Filed Deo. 2O 1920 without seriously departing i wasted by an upper water Patented Jan. 5, 1932 UNIT-ED STATES PATENT orrrcl;v

WILLIAM D. I-IOXIE, DECEASED, LATE OF WESTERLY, RHODE ISLAND, BY

EOXIE, 0F WESTERLY, RHODE ISLAND,

WASHINGTON TRUST Wren, counnofrron'r, AND THE LAVINIA '.B. OF GREEN- WESTERLY,

ISABELLE HOXIE IT'IIDDLETON, COMPANY, OF

RHODE ISLAND, EXEGUTORS, ASSIGNOR TO THE BABCOCK 8c WILCOX COMPANY, OF

BAYONNE, NEW JERSEY, A

CORPORATION OF NEW JERSEY WATER TUBE BOILER Original application led December 20, 1920, Serial No. 431,975. Divided.v and this application led July 23,1927. Serial No. 207,905. f

rIhis invention relates to water tube boilers, particularly of the type adapted fo'r marine use, this application being a division of application Serial No. 431,97 5, filed December 20, 1920.

One of the objects of this invention is to produce a boilerl which will be compact in.

form and efhcient in operation. Another object of this invention is to provide a boiler which will have a minimum tendency to form scale if the feed water for the boileris imure. p With these and other objects in view, this invention consists in the constructions here-y inafter described and specifically pointed out in the appended claims.

In the accompanying drawings, Figure 1 is a front elevation, partly in section, of

an illustrative form ofboiler to Which thS present invention has been applied, and Fig. 2 is a side elevation of the illustrative boiler with parts of the outer wall broken away.

Similar reference lar parts in the several views.

In modern marine boiler practice, it is frequently desirable to provide superheated steam. It is also desirable that such superheated steam may be provided eliiciently from the type of boilers which have come into common use for marine work. It is also desirable to design such boilers so that, so far as possible, the heat of the furnace will not be passing into the boiler room to the. discomfort of thevoperators, The-boiler of the present invention is designed to accomplish these purposes.

In the illustrative form of boiler, 10 is drum and 11 and 12 'lower water drums, the latter being spaced apart to `accommodate afurnace chamber between them, this furnace chamber being of any d-esired form and, `in the instance-illustrated, being adapted for oil fuel, the oil being introduced through burnersprojected through the openings in the furnace vshown in the drawings. Each of the drums 11 and 12are connected withthe upper drum by a set lof water tubes 12', 13. For reasons which will be explained more fully hereinafter, in the boiler and numerals indicate simi- Y l through thebranches 21, 22 withthe compartments 14 and 15, respectively.` The feed water form of boiler illustrated, the upper drum 10 is provided with water compartments 14, 15which, as shown best in Figure 2, are preferably located centrally vcrosswise of the are much shorter than the length of the drum 10. The drums 11 Vand 12 are also provided with compartments 16, 17 which extend the entire length of the lower water drums. The two rearmost rows of tubes 18, 19 are divided.y into three groups of tubes, the tubes of the central group connecting the compartment 15 with the compartment 17 on similar group of the set 12 connecting the compartment 14 withthe compartment 16. The remainder'of the tubes of the rows 18, 19 which come in front and at the rear of the compartment 15, connect the compartments 16 and 17, respectively, with thev drum 10, this being accomplished by the fact that the compartments 14 and 15 are shorter than the lengthof the drum 10. f

A feed water supply'pipe 20 communicates `ber Vis closed onits outerside and is open on the side adjacent the set of water tubes. In each chamber is a superheater which, in the formfillustrated, is composed of headers 25,

V26 of the usualtype, the inlet Vheaders 26 one side of the boiler, and a being connected through the pipes 27 with the saturatedsteam outlet'28. The superheater tubes, which are illustrated as vofy the U-shaped type, extend from the headers 2 5, 26 in the usuall manner and lie crosswise of the sets of tubes v12', 13 in the chambers 23,24.' v. v`

In the form illustrated, superheater tubes is carried extending upwardly from the lower the weight of the on a support 29 drum beneath the superheater headers. At the opposite end the U tubes may be supported by a rack 30 provided with a number oftougues each adapted to extend beneath a superheater tube, this rack being clamped to the rearmost of the water tubes by any suitable device, such aslclampsl and strap connections 32 connecting the upper end of the -racl to the drum l0. Y i

A battle 33 extends from the lower water drum upwardly along the set of water tubes and, in the form shown, behind the second row of such tubes from the furnace chamber. The tops of the battle '33 are removed from the upper drum l0 a sulificient distance to permit the gases from the furnace chamber to flow up along `the baiile 33 and then enter among the water tubes .at substantially rightangles thereto. At .the upper endsof the bafes 33 are provided cross battles which extend substantially across the set water tubes and therefore to the open side of the superheater chamber. At the lower end of each superheater chamber is preferably provided a second cross bafile which is short enough to permit the gases tok pass between its lower end and the battle 33. The parts are also proportioned so that the gases may pass between the ba le 35 and the corresponding lower Vwater drum.'l

Outside of the superheater chamber and the portions of the watertubes below such chambers, extend .side Walls 36, 3'? which are removedrfrom the superl eater chamber and kthe tubes a suicient distance to provide a gas passage upwardly yto the usual gas outlet. The walls 36 and 37 may be insulated in tl e usual manner to prevent the passage of heat.

The furnace and then divide with a portion passing into each of the sets of water tubes 1QV and 13, in each of which the gases first pass across the water tubes `at their upper ends and then flow over the superheater tubes in a generally downward direction into the second pass between the baflles 34, 35 and fromthence again across the tubes into the gas passage adjacent the side walls 36, 37 to the gas outlet. Y

It will be seen that, by providing' the baille 34, as shown, the gases are forced to flow entirely over the superheater tubes after thel gases have passed across the water tubes, and that the circulation to and from the water tubes and around the superheater tubes is positivean-d definite, so that the operating conditions will not fluctuate unduly under different conditions of service. By interposing the superheater with its chamber between the water tubes and the gas outlet, a minimum amount of heat that might be absorbed in generating the superheated steam is permitted to escape Vinto the re room throughthe side walls, asthe spent gases serve to assist in insulating the boiler and superheater against such a loss. rEhev sides the upper part of `will be understood gases risealong the baffles 33 ments is particularly adapted are in reality jacketed with the spent gases, which serve more effectively to prevent such a radiation loss than the non-conductive covering and casing ordinarily employed.

If desired, the baille 35 may be omitted, and it will also be understood that the baille 33 may be placed either entirely in front of the set of water tubes -or .behind as many as is found desirable. While it is desirable, for well known reasons, to provide a boiler with a double set of water tubes as illustrated, it that certain parts of my invention may be applied to a boiler having one lower water drum only and one set of tubes. A ydouble boiler of the type illustrated is desirable, however, because `by providing a set of water'tubes and afsuperheater on either side of the furnace chamber, a minimum amount of heatis ermitted to escape into the boiler room. 'uitable dust doors and dust blowers may be provided in the several passes, as shown, to freethe tubes from dust.

The upper andlower water compartments areprovided with the arrangement of the water tubes connecting these compartments, hereinbcfore described, in order to purify the feed water as much as possible before the feed water enters the general circulation of the boiler. It is well lmown that water containing certain impurities in `particular will have such impurities precipitated by heating the water to a relativelyV high temperature. Such precipitation in itself, however, is of no advantage unless the precipitates have an opportunity to settle down and thus become separated from the water. 'The best resultsV will be obtained by rst heating the feed water as rapidly as possible in its journey from the feed water inlet into the general water circulation, so as to cause it to reach a temperature suiiiciently high to cause precipitation the beginning of this journey, and then allowing the water to' travel over a relatively long path arranged so that the precipitates may separate out, and in which the temperature of the water is being gradually raised but "so as not to boil, and thus agitate the water until the precipitates have had an opportunity to settle out. The arrangement of the water tubes connecting the compartto accomplish these ends. As the feed water passes from an upper compartment, as 15,-i't crosses the first pass, at which time the rgasesare still very hot, since they have beencooled only by once. In crossingthis first pass, therefore, the relatively cold feed water iszraisedvery quickly -to a temperature sutliciently high to cause precipitation. `In the next portion of its journey downward, this water passes across the second passin which they gases are considerably cooler than in the lirst pass by reason of their previous passage over the superheater tubes. 1n the passage of this water across the third pass,`it is contacted with the relatively cool gases which are passing to the gas outlet. 1n the lower water compartment, the water turns and flows substantia-lly horizontally, and from thence upward through the remaining tubes of the rows 18 and 19. ln these rows, the temperature of the water is gradually raised by reasn son of its passage across progressively hotter gas passages. It will be noted, therefore, that the feed water is first heated to a high temperature and that, in its continued travel downward and thence upward, additional heat is supplied in such a way that the temperature of the water is raised relatively slowly, and that, by reason of the direction of flow of the water, and particularly its spreading out in the lower compartment, the precipitates have full opportunity to settle out without being disturbed by the ebullition of boiling water.

For some purposes, some of the same results might be obtained by having the upper compartment connect with a lower compartment by a row of tubes extending entirely across the boiler, as the row 19, with the lower compartment connecting with the drum through the entire row 18 of the tubes. Such an arrangement, however, would permit at least some of the water flowing downward through the tubes19 to return immediately through the tubes 18 without remaining for any time in the compartment 16 or 17, and thus not be subjected to the settling action which results when the water necessarily travels horizontally in that chamber as it does with the arrangements which are illus-- trated.

Blow-off coc-ks are provided both for the lower water compartments and the lower water drums, such blow-oil' cocks being par ticularly desirable on the lower water compartments in order to remove the precipitates which may be thrown down and carried into those compartments from the feed water.

lhile, preferably, the upper and lower water compartments are formed directly in the upper and lower water drums, respect-ively, it will be understood that such compartments may be formed independently of these drums. Y

It will also be understood that any suitable type of superheater, other than the U-shaped one illustrated, may be used.

What is claimed is: Y

1. A steam boiler comprising an upper and a lower drum and a set of tubes connecting the drums and arranged inV rows across the boiler, a furnace chamber adjacent the set of tubes, bailies arranged to cause the furnace gases to enter among the tubes at their upper ends and pass entirely across saidupper ends and thence back and forth across the tubes in a generally downward direction, an upper water compartment, a feed water supply connected thereto, and a lower water compartment, some of the rearmost tubes of the set connect-ing the upper and lower compartments and others of the rearmost tubes connecting the lower compartment with the upper drum.

2. A steam boiler comprising an upper and a lower drumand a set of tubes connecting the drums and arranged in rows across the boiler, a` furnace chamber adjacent the set of tubes, baflies arranged to cause the furnace gases to enter among the tubes at their upper ends and pass entirely across said upper ends and thence back and forth across the tubes in a generally downward direction, an upper water compartment, a feed water supply oonnected thereto, and a lower water compartment, the tubes of one of the rear rows of the set being divided into three groups crosswise of the boiler, with the tubes of the central group connecting the rupper and the lower compartments and th-e two end groups connecting the lower compartment and the upper drum.

LAVINIA B. HOXIE,

TSABELLE HOXIE MTDDLETON,

THE WASHINGTON TRUST COM- PANY, WESTERLY, R. I., By THOMAS PERRY,

Trust Ojecr, Emecutors of the Estate of William D. Howie,

Deceased.

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