US1748137A - Water-tube boiler - Google Patents

Description

Feb. 25, 1930. K.` L. MARTIN WATER TUBE BOILEB l Fid Feb. 20. 1928 l Paare@ ab. 25, ma 1,748,137

UNITED STATES PATENT; OFFICE KINGSLEY AI. MARTIN', OF '.MIG'IITGILAIR, NEW JERSEY, ASSIGNOR 0F ONE-HALF T0 A. c. BANKS, or' CLEVELAND, OHIO waarna-'Irunn Borrar.

Application filed February 20, 1928.v Serial No. 255,558.

i .This inventionv relates to water tube'iboiler soot chambers ordinarily provided behind the construction and particularly tothe vertical lower drum whence it is readily removed at benttube types known as Stirling, Connelly, and others. The best known of these employ a bottom drum and three spaced upper drums with a setfoftubes extending from the bottom drum to eacheupperdrum but in some cases there are only twoupper drums and two banks of tubes. The invention has tov ydo primarily with the protection ofthe upper and lower drums from destructive action -by the gases of combustion and secondarily to improve the operating eiiiciency of the boilers by preventing the accumulation of soot A and dust in .the gas passageways, principally on top of the lower drum by a novel arrangement of refractory bailes in the boiler.

First asregards the protection of the lower drum. It has been customary to use baiies in oron' the first bank' of tubes parallel to their length so that soot, ashes and dust deposit in the angle formed by the baie and upper .surface of the drum and in Contact therewith. This accumulation, contains chemical agents I which attack the metal in the tubes and drum and gradually corrodes them to such an extent that their lreplacement is necessary. Owing to the inconvenient location lof the parts attacked, inspection is dicult and a dangerous condition may develop apartirn I the expensive nature of repairs. This action is prevented by my invention, which provides fora novel construction of the lower end of the front baille' by which the baflie in-` stead. of' being continued along the tubes of the first bank is constructed transversely across said tubes ina downwardly sloping direction across the space between the first and A second bank 0f tubes and partly or whollyv across the second and third bank ofy tubes and passing over the lower drum. By this means 'a smooth sloping shelfisprovidedon which, due tothe scouring actionl of the gases V atthis point, acting on the smooth inclined' surface, only a small portion of thev solid matter entrained` in the gases will deposit, the vbalance being carried over behind the lower drum 'and dropped out voi' suspension 'by theexpandinggases as their velocity is '50 reduced. The solld'matter will then fall into convenient intervals.

The removal of such solid matter, as does deposit on the upper surface of the sloping baliie, may be eiected by the ordinary type of steam soot blowers or by hand lances, but pending such removal, the material is held out of Contact with the junction of the tubes and drum where its corrosive actionis greatest. The prevention of the dust accumula-' tion also avoids an increase in `draft loss through the boiler :due to obstruction of the gas passage and maintains the thermal eiiiciency by preventing the covering of part of the heat absorbing surface by dust having high insulating qualities.

Provision is also made against overheating the rear upper drum. In this type of boiler, the rear drum at low capacity operation is approximately half full ofwater, the upper half being lled with steam, but when operating. at high capacities, the water level is lowered, and may sink into the upper part of the rear bank of tubes leaving the drum full of steam only. As the type of cross baffiing, preferably used, brings gases at high temperature in contact with the drum, it is necessary `to protect the drum particularly the vjoint or splice between'the upper and lower halves of the drum. This splice-must also be left uncovered for inspection. It is also desirable to protect the junction of the upperl end of the rear bank of tubes with the drum.v vSuch upper drum protection, as has heretofore beenprovided consists of loose refractorytile laidon some of the steam generati-ng tubes kof the boiler or on water circulatingv tubes between the drums. These loose tile are necessarily not gas or dust tight, and where pulverized coal is used as fuel, unburned fuel lmay 'penetrate the baiie and become an element of danger from explosion. I have, therefore, provided a construction applicable to practically all types of boilers o this kind now in use, wherein aibaie is placed between the middle and rear drums starting from approximately the point where the rear tube of the middle bank Jof tubes enters the middle and extending rearwardlyyno either horizontally or inclined downwardly until it meets the front surface of lthe rear drum atsome point below the drum splice and thence following the outer lower surface of the drum through and around the upper ends of the tubes in the rear bank to a junc- -tion with the rear baliie wall which extends downwardly from the drum. A downwardly inclined baiie between the drums is preferred where the tube arrangement permits, as fa- `cilitating the change of direction of the gas flowbelow it at this point, and preventing the formation of eddy currents. The baiiie consists of plastic refractory material, reinforced with rods or shapes embodied in the material,

- so as to be protected from the hot gases, formv alleys, between them, the wide alley being vused to remove defective tubes. The narrow alley only would preferably be used for the reinforcing. Certain embodiments of the in-V vention are shown in the accompanying drawings, wherein:

Figure 1 is a vertical section through a water tube boiler constructed in yaccordance,

with my invention. Fig. 1a is a detail of one of the baflies. And Figs. 2 and 3 are vertical sections through modifications.

Referring to Fig. 1, the numbers 1, 2' and 3 indicate the upper drums of the boiler and 4 is the lower drum, such drums being connected by the three banks of tubes 5, 6 and 7. The upper drums are connected by the usual sets of tubes 8 and 9. The boiler may be provided with the usual hand fired grates or with automatic stokers, with gas, oil or powdered coal burners, the invention not being limited as to this detail of construction. Following the usual practice, the side 10 of the construction on which the gases of combustion enter the tubes will be referred to as the front side and the other side (left) on which the outlet flue 11 is located will be referred to as .the rear side, the banks or sets of tubes and drums being -correspondingly designated. Combustion takes place in the`lower part of the furnace whose upper part 10 lies between the front wall 12 yand the front tube bank 7. The ow of the gases of combustion across the banks or sets of water tubes 7, 6, 5 is governed v and directed by a pair'of baffles arranged in part as described in Patent No. 1,614,948 isl sued to Alfred C.y Danks, which in part is modified so as to constitute an important feature of my mvention. The rear baffle is made vup of two sections, the upper section 13 extending downwardly from the rear drum 1,

between the tubes in the rear tube bank 5, for a portion of their length and thence (part 14) in a direction transversely to said tubes across the tubes in the middle bank 6.

The front baie is made up of three sections, the upper 15 passin transversely across the upper part of the mi dle tube bank 6 and the intervening space to the front tube bank 7 It may then follow the back of the rear tube of this bank downwardly or enter the tube bank any desired distance and follow any tube downwardly, as shown at 16, a convenient distance, and then turn to the rear 17 and cross the space between the irst and second tube banks and the lower part of the middle, and if desired, the rear bank in a downwardly sloping direction, passing over the lower drum.

Between the lupper rear drum 1 and middle drumf2 is shownythe suspended baffle 18 for the protection of the drums, and particularly the drumsplices 20', with an extension bailie 21 following the drum 1 and passing between and surrounding the upper ends of the tubes in the bank 5 to a junction with the rear baiile 13. This baile is provided with any suitable form of reinforcing 18, as indicated by the dotted lines in Fig. 1, and may be suspended by rods 23 from the tubes 8. similar baille 22 may be suspended between the middle and front drums 2 and 3 so as to protect the splices 20 on these drums. As the circulation in the boiler is such that there is always water in these drums further protection is unnecessary. The construction, being independent of all tube sup ort, the latter yare left. uncovered for heatna sorption, may be readily inspected and on occasion, removed. Other advantages incident to the construction which may vary in details to suit other makes of boilers, will be readily apparent to those skilled inthe art.

Fig. 2 shows only enough of the upper portion of the construction to illustrate'a modified baille 18'l between the drums 1 and 2 with supporting rods 23. The tubes 24 of the Fig. 1 construction are not used here so that the modified form of baille 18 as shown 'may be used.

ln the Fig. 3 construction, water circulating tubes 25, not present in Fig. 1 construction, are used, the baille 18 supported z by the hangers 23" being similar to the baille and hangers of the Fig. 1 construction.

What I claim is: A 1. 'In-combination in a boiler of the vertical type havin -lower and upper drums and a plurality o sets or banks of tubes Vextending between the upper and lower drums and including al front bank and a Asecond. bank ad'- jacent thereto, a rebox beneath the boiler,

anjoutlet flue or stack at the rear of the boiler, a substantially flat baille extending transversely across the top of-the lower drum in proximit thereto and upwardly inclined into theront bank of tubes above said lower drum, and an extension of the upper end of said bafie extending longitudinally of said front bank of tubes, and then transversely of such tubes and across the secondbank of tubes.

2. In combination in a boiler of the vertical type having lower and upper drums and a. plurality of sets of tubes extending between the upper and lower drums, and in` lcluding-front, middle and rear banks, a irebox beneath the boiler, an outlet Hue or stack at the rear of the boiler, a. substantially Hat inclined baiiie extending transversely across the top vof the lower drum through the middle bank of tubes and tangential to the lower drum, then longitudinally of the tubes of the front bank, and finally across the tubes of the middle bank.

3. In combination in a boiler of the vertical bent tube type having a lower drum and three spaced upper drums and three sets or banks of water tubes extending upward from the lower drum to the upper drums, a furnace beneath the boiler, an outlet flue or stack at the rear of the boiler, a baiile extending downwardly from the rear upper drum, longitudinally along the tubes of the rear bank for a portion of their length and then transversely to such tubes and across the middle bank of tubes and a second baiiie extending 'down- Wardly from a point between the upper portions of the middle and rear tube banks across the middle bank of tubes to the first bank of tubes, thence downwardly parallel` to said tubes a portion of their length and thence to the rear and downwardly over the top of the lower drum tangentially thereof.

4. In a boiler of the vertical tube type having a lower drum and a plurality of up er drums with a plurality of banks of tubes etween the` upper and lower drums, cross baffling between the upper and lower drums, a

baiiie lying in the rear bank of tubes and extending downwardly from the rear upper drum and then forwardly into the next bank of tubes, and a baffle section of reinforced plastic material hardened in place suspended from above and extending between the rear upper drumand the drum next to it, and another baile section of reinforced plastic Inaterial hardened in place secured at one end to said baiiie section and following the curvature of the lower side of the rear upper drum and extendin into the tubes to a point where it engages an is supported by the upper end of the bae in the rear bank of tubes.

In testimony whereof, I have hereunto subscribed my name this sixteenthday of February, i928.

` KINGSLEY L. MARTIN.

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