US948373A

US948373A - Tubular steam-boiler.

Info

Publication number: US948373A
Application number: US41429208A
Authority: US
Inventors: Sterling Elliott
Original assignee: Individual
Current assignee: Individual
Priority date: 1908-02-05
Filing date: 1908-02-05
Publication date: 1910-02-08
Anticipated expiration: 1927-02-08

Description

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I A s. ELLIOTT. TUBULAB. STEAM BOILEB.

APPLICATION FILED PEB. 5,1908.

948,373. Patented Feb. s, 1910.

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UNITED STATES PATENT oFFIoE.

STERLING ELLIOTT, OF EWTON, MASSACHUSETTS.

TUBULAB. STEAM-norma.

Specication of Letters Patent.

Application led February 5, 1908. Serial No. 414,292.

To all whom 'it may concern:

Be it known that I, STERLING ELLIOTT, of Newton, county of Middlesex, State of Massachusetts, have invented an Improvement in Tubular Steam-Boilers, of which the following is a specification.

This invention relates to tubular steam boilers. In the manufacture of boilers `vof this type ithasbeen customary to expand the ends of the tubes into theholes in the tube plates, and to bead or turn the ends of the tubes over upon the exterior surfaces of said plates to thereby vconnect thejtubes with the plates. Oftentimes the boiler leaks at the joints, due to imperfect connections of the tubes therewith, and also to imperfect connections between the shell and tube plate, which is very objectionable. Furthermore,

the boiler immediately begins to Icorrode` both interiorly and exteriorly, interiorly by the action of the water which 1s contained in it, and exteriorly by the action of the sweat which accumulates on it, when cold, due to'V the moisture of the air condensing on it, and as a result of such corrosion the life of the boiler is materiallyT shortened.

The invention has for its object to provide all parts of the boiler or essentially all parts thereof, which are exposed to the waterland to the air, but particularly all parts which are exposed to the water, with a covering,

which is united to the surfaces which are.

thus exposed, and which fills all accessible interstices between the end portions of the tubes and the tube plates, said covering` consisting of a non-corrosive metallic substance having a high melting point, to thereby prevent leakage at the jomts and to prevent corrosion or to retard the action of .corrosion to such an extent as to materially lengthen vSuch a non-corrosive covering preferablyA extends continuously over the entire exterior and interior surfaces of the tubes and of the tube lates to which they are connected but especially extends continuously over the surfaces thereof which are exposed to the water, or at least, over the end ortions of the surfaces thus exposed, and orms fillets around the tubes at the junction of the tubes and the tubel cially over 4the surface thereof whichs exposed to the water.

The invention also has forits object to i provide the boiler with a plurality of outlets for the steam which lead fromthe same lsteam space and which are connected to a common delivery pipe, of steam may be taken different points.

Figure l is a plan view of a tubular steam boiler embodying this invention. Fig. 2 is avertical section of the boiler shown in Fig. l, taken on the dotted line 2 2, one row of tubes. only being shown.v Fig. 3 is an enlarged detail of the end portion of one of the tubes showing its connection with the tube plate. Fig. 4 is a detail showing the end portion o f the boilershell. tional detail of one 'of the tubes and portions of the two tube plates and a portion of the shell, the ends only of which are covered. Fig. 6 is a vertical-section of one of the elements o-f the boiler'havinga contin-. uous non-corrosive metallic covering united whereby the supply .from the boiler at thereto, and Fig. 7 is a vertical section ofV the other element ofthe boiler having a conunited thereto.

Fig. ,5 is'a secai represents the tubes, b the tube plates formed in any well known or suitable manner, so far as my invention 1s concerned. The end portions of the tubes are projected into the holes in the tube plates and slightlyv but not severelyexpanded to thereby conneet them therewith. The tubes and tube plates, thus assembled, are vin condition to have applied to them, both intericrly and exteriorly, a non-corrosive metallic substance having a high melting point which forms a protecting covering which is united to thel surfaces to which it is applied, `and which fills all accessible interstlces at the joints, and forms fillets around the tubes at the junction of said tubes and tube plates. The shell c, Ywhen adapted to be attached to the tube plates, is likewise in condition to be similarly treated. As a non-corrosive meltallic substance having a high melting point -I prefer to employ brass, but IV may employ any other suitable material which is adapted for the purpose. I particularly prefer brass for the reason that. its melting point is so high that the temperature of the boiler even under cxtraordinar conditions will notI melt it. To easily apply the non-corrosive metallic substance to both the interior and exterior surfaces, I prepare a bath of molten brass and into this bath I entirely submerge the assembled t-ubes and tube plates, or I may only dip the .end portions thereof, and also entirely submcrge the tubular shell, which at such time is not attached to the tube plates, or I may only dip the end portions thereof. In Fig. 2 the parts are represented as entirely cover-ed, and in Fig. 5 the end portions only are covered. Previous to attaching the tubes to the tube plates, both the tubes and tube plates. are subjected to any suitable abrading treatment or pickling process and the shell islikewise treated. The brass is caused, by means of a suitable flux, to imite to all of the surfaces with Which it comes in contact. The non-corrosive metallic substance may, however, be united to the surfaces in any other suitable manner. Uien the parts are thus coated it will be seen that both the interior and exterior surfaces of the tube plates are uniformly covered and thereby, protected from corrosion, and that the covering is united to said surfaces, and as said plates are coated previous to the shell c being attached to them, the flanges b thereof are entirely covered, and thereby protected. Furthermore, that both the exterior and interior surfaces of the tubes, or at least the end portions thereof, according to the depth the boiler is dipped in the molten metal, are uniformly covered and thereby protected from corrosion, and that the covering is united to said surfaces. Furthermore, that the coverings on t-he end portions of the tubes and on the tube plates, if the end portions of the assembled parts are separately dipped in the molten metal, or the single covering on the tubes and tube plates, if the assembled parts are entirely submerged, is continuous, in thatit extends over or throughout both the tubes and tube plates, in intimate contact therewith, in an unbroken or continuouslayer. Furthermore, that all accessible interstices between the ends of the tubes and the tube plates on the interior surfaces of said tube plates are filled from both sides of the tube plates, and that at the junction of the tubes and tube plates fillets, represented at c, Fig. Q, are formed around the tubes which are integral with the covering Which is united to tubes and tube plates, and also with the material which enters the interstices between said tubes and tube plates. By coating the tubes interiorly from end to end, so as to prevent corrosion along their entire length, smooth inner surfaces are produced andfmaintained whichlargely preventsthe deposit and accumulation thereon of soot, but coating the tubes exteriorly, where exposed to the action of the water is of the greatest importance. I `urthermore, it will be seen that all the. ex posed surfaces of the shell, or at least the end portions thereof, according to the depth it is dipped in the molten metal, are covered and thereby protected from corrosion and that the covering is united Ito the surfaces thereof. Furthermore, that by covering the connected tubes and tube plates in the man ner described or in some equivalent manner, whereby a continuous or integral covering is provided for and united to said parts, having integral illet around the tubes at the junction of the tubes and tube plates, the tubes need not necessarily be as severely expanded into the holes in the tube plates i. is now the practice, which reduces the cost of assembling the parts, and avoids the danger of (glishiug the tube plates from the combined strain of a number of small severely expanded tubes.

In small boilers having` a large number of tubes the. tubes are placed very close to,- gether. This increases the liability of crackig the tube plates between the tubes when said tubes are severely expanded in place, or subsequently when the tubes are rexpanded for the purpose. of stopping leaks.

()bviatiug the necessity of expanding and Ireexpanding the tubes into the holes iu the tube plates permits the employment of thinner tube plates than has heretofore been customary to use with a corresponding increase in the'heating eti'iciency and a reduction in the cost as well as weight.

The shell c of t-he boiler may be reinforced by means of bands c or by any other suitable means adapted to encircle it,land in such case the reinforcing means will be applied to the shell before the shell is subjected to treatment, then the shell will be subjected to the aforesaid treatment resulting in both the shell and the reinforcing means having a continuous non-corrosive metallic covering or coverings having a high melting point, united to its interior and exterior surfaces, which tills all accessible interstices between said shell and the reinforcing means there on. Arranging the reinforcing means on the shell previous to subjecting the shell to treatment permits the employment of a much thinner shell than has been customary to employ with a corresponding reduction in the cost and weight, and if bands are employed as the reinforcing means they may be arranged to cross the grain of the metal of theI shell, and when covered to become practically one piece.

The tubular, cylindrical shell -c of the boiler will have attached to its outer side several plates c2, having holes through them arranged opposite corresponding holes in the shell for the purpose of connecting an indi- -ator thereto or for other purposes. These plates are attached to the shell before the shell is subjected to treatment and the shell having the plates attached to it is then subjected to treatment in the manner before described, resulting in both the shell and plates having a continuous non-corrosive metallic covering having a high melting oint united to its interior and exterior sur aces, which enters all accessible interst-ices between the plates and shell.

In steam boilers there is a tendency for the water to lift when the outlet valve is opened and in some cases, especially in small boilers. when the pressure is high and the water level also high the water is carried through thc throttle into the engine with very undesirable results. Such action not onlyv draws the Water from the boiler with a great loss of heat, but has abad effect on the running of the engine. To obvia'te this objection two or more openings are provided in the top tube plate, which are located some distance apart, and made quite small, and said openings uhich serve as outlets leadiiw from the same steam space are connected by pipes b2 with a common delivery pipe b, which latter serves as an outlet common to all the aforesaid small openings in the top of the boiler. The areas of the several small outlets Will approximately equal the area of the common outlet. Having thus described 'my invention, what I claim as new and desire to secure by Letters Iateut is U' l. In a tubular steam boiler, a tube plate anda set of tubes connected therewith, and a continuous non-corrosive metallic covering having a high melting point united to both the exterior and interior surfaces of the tubes and to both the interior and exterior surfaces of the tube plate, and forming integral fillets around the tubes at the junctions thereof1 With the tube plate, substantially as described.

2. In a tubular steam boiler, a set of tubes and a pair of tube plates to Which said tubes are connected yat their opposite ends, and a continuous non-corrosive metallic covering having a high melt-ing'point united to both the exterior and interior surfaces of the tubes and to both the exterior and interior surfaces of both tube plates, and forming integral fillets around the tubes at the junc tions thereof With the tube plate, substantially as described.

3. A tubular steam boiler composed essentially of a pair of tube-plates and a set of tubes attached thereto, entirely coated with a continuous, non-corrosive metallic substance having a high melting point, and a shell, also entirely coated with a like substance, attached to said tube-plates, substantially as described.

'In testimony whereof, I have signed myname to this specification, in the presence of two subscribing Witnesses. A

STERLING ELLIOTT.- I/itnesses B. J. NoYEs, H. B. DAVIS.