US1437790A

US1437790A - Boiler

Info

Publication number: US1437790A
Application number: US472230A
Authority: US
Inventors: Wright Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-05-24
Filing date: 1921-05-24
Publication date: 1922-12-05
Anticipated expiration: 1939-12-05

Description

P. WRIGHT.

BUILER.

APPLICATION FILED MAY24, I921. 1,437,790. Patented Dec. 5, 1922.

6 SHEETS-SHEET 1- WITNESSES INVENTOR H/S' HTTOIP/VEYS P. WRIGHT.

BOILER.

APPLICATION man MAY 24. 1921 1,437,790. Patented Dec. 5, 1922.

5 SHEETSSHEET 2- FIG. 2

' IV/ TNESSES nvmsw TQR HIS HTTORNEYS P. WRIGHT.

BOILER APPLiCATlON 'HLED MAY 24. um,

1,437,790, Patented Dec. 5, 1922.

5 SHEETS SHEET 3 [VITA/5558 lNVEA/TUR W m/ BY HIS nrrokA/e'ys P. WRIGHT.

BOILER.

APPLICATION mu) MAY24.1921.

1,437,790, Patented Dec. 5,1922.

6 SHEETS-SHEET 4.

WITNESSES l/Vl/EN TOR HIS HTTORNEYS 57 %M 0mm, MW,

P. WRIGHT.

BOILER.

APPLICATION FILED MAY24, I921.

1,437,790. Patented Dec. 5, 1922.

6 SHEETSSHEET 5.

kg El,

m r/vzssss V awe/v 7'02 5v. M, im mm Hi6 HTTORNEYS P. WRIGHT.

APPLICATION LED MAYQ". I921 1,437,790. Patented Dec. 5, 1922.

5 SHEETS SHEE] 6 FIG. G

w/r/vzssss nwzzv TOR m 71 LMW 5 r HIS HTTORNE Y8 Patented Dec. 5, 1922.

UNITED STATES PATENT OFFICE.

PAUL WRIGHT, OF BIRMINGHAM, ALABAMA.

BOILER.

Application filed May 24, 1921.

To all whom it may concern:

Be it known that I, PAUL VVRIGHT, a citizen of the United States of America, and a resident of Birmingham, Alabama, have invented new and useful Improvements in Boilers, which invention is fully set forth in the following specification.

This inventionrelates to improvements in water-tube boilers of that general type in which three main drums are triangularly disposed in series communication through interposed banks of tubes with a lower bank rearwardly declined over the fire-box.

The invention has for its object a novel arrangement of drums and tubes in relation to each other and to a bafiling for directing the heated gases that provides an efficient generation of steam and its separation from the water and, by the compact association of the component parts, permits economy in the construction of the supportin frame and in the furnace setting.

The means whereby this novel advantageous arrangement is obtainedis set forth in detail hereinafter and fully illustrated in the accompanying drawings.

In the drawings, in which similar reference characters designate corresponding parts Fig. 1 is a vertical longitudinal section of a boiler embodyin the invention;

Fig. 2 is a half ront elevation and a half vertical transverse section;

Figs. 3, 4 and dare, respectively, vertical longitudinal sections of different modifications of the invention; I

Fig. 6 is an enlarged. longitudinal sectional view of the steam drum, showing the separator mechanism;

Fi 7 is an end view of the same with the ead removed, showing the sectional Separator plate.

Referring particularly to Figs. 1 and 2, the boiler comprises a supported bottom or mud drum 1, a suspended front or water drum 2, and a supported top or steam drum 3, in the relation t at the front drum is forward of and above the bottom drum, the top drum backward of and above the front drum and also forward of the bottom drum. These drums are connected by three banks of tubes having the relation that the first bank 5 connects the upper ri ht hand (as shown in Fig. l) quadrant 0% the bottom drum 1 with the lower left hand quadrant of the front drum 2, thereby providing a Serial No. 472,230.

gradually ascending bank between the two drums over the fire-box; the second bank 6 connects the upper left-hand quadrant of the front drum 2 with the lower right-hand quadrant of the top drum 3, thereby provldlng an ascending bank nerally inclined forward from the verticfi and the third bank 7, considerably longer than the first and second banks, connects the lower lefthand quadrant of the top drum 3 with the upper left-hand quadrant of the bottom drum 1, thereb providing a descending incllned bank. he first bank 5 is preferably somewhat lon er than the second bank 6, but they may e of the same length, or approximatel so.

The inclination of the line connecting the centers of the

drums

1 and 2 is at an angle of about 24 from the horizontal and the inclination of the line connecting the centers of the

drums

2 and 3 is at angle of about 10 from the vertical. These angles of inclination are only approximate and have been arrived at by practical experience as being advantageous, but may be varied somewhat to meet different requirements. The tubes of the several banks have the usual bends to accommodate the radial entrances of their respective drums and also to permit yielding to compensate for the contraction and expansion caused by variations in temperature. These bends in the members of the bank 5 cause a more acute inclination relatively to the horizontal in the general direction of the tubes than the lines connectin the centers of the

drums

1 and 2; and t e bends in the membersof the bank 6 impart a general direction to the tubes that inclines them slightly forward from the vertical toward their upper ends, althou h the line connecting the centers of the

rums

2 and 3 is inclined rearwa'dly from the vertical toward its upper en In this way a circulating system is provided that consists of mud, water and steam drums triangularly disposed and communicating in series through interposed banks of tubes, with the mud drum positioned adjacent the bridge-wall of the furnace the water drum adjacent the trout wall 0 the furnace and somewhat elevated above the mud drum, and the steam drum above and slightly to the rear of the water drum. The bank of tubes connecting the mud and water drums, owing to the bends in the ends of the tubes, is inclined over the fire-box at a slight" angle to the horizontal and the bank connecting the water and steam practicall upright. The bank connecting the u and water drums is slightly longer than the bank connecting the water and steam drums, while the return bank connecting the steam and mud drums is considerably longer than the other two.

The advantages obtained in circulation and steam disengaging capacity of the boiler as the result of this definite relation of drums and banks of tubes may be appreciated in considering that the feed-water enters through a perforated distributing pi e 9 into the drum 1 where it mixes with the heated water in circulation'and eflects immediate separation of scale-forming substances within this drum so that the same may be blown off through the blow-off pipe 10 and that this method is superior to feeding through a trough in the top drum, which would cause cooling of the steam and probable deposit of scale matter in the rear bank of tubes 7.,

The water in bank 5 is subject to the first or hottest passes of the furnace gases, and steam forms rapidly and causes the water and steam to ascend in the tubes to the drum 2 since the density of the mixed water and steam in bank 5 is less than in bank 7, the latter being heated by passes of cooler gases. The shape and general direction of the tubes in bank 5 are such that the formation of steam pockets and possible lodgment of scale near the drums are prevented. As the mixture of water and steam flows from bank 5 into drum 2 and thence into bank 6, it is further heated, producing a mixture of less density in bank 6 than in bank 5 and, therefore, a greater difl'erence obtains between the relative densities of the fluid in banks 6 and 7. In drum 2 the steam quickly separates from the water by rising to the upper part of the drum and enters bank 6. The fluid in bank 6 is steam in a large art and the flow of the same therethroug is accelerated by the approximately vertical position of the tubes in said bank. As the mixture of steam and heated water in

banks

5 and 6 has much less density than the fluid in bank 7, the mixture has a strong tendency to flow upward in

banks

5 and 6. This tendency is particularly accommodated by the nearly vertical position of the bank 6, and an enhanced circulation results therefrom. Where the second bank of tubes, the bank leading from the water drum to the steam drum, is horizontal or approaches such osition, the movement of the fluid therein 18 apt to be sluggish, as it depends on the energy im arted by the ush of the fluid in the prece ing bank an on reduction in the advance ressure by withdrawal of steam for service purposes. By

positioning the second bank of tubes in an upright position, or nearly so, the circulation is considerably accelerated. The passage of the water and steam through the upright bank 6 not only accelerates the circulation, but induces a rapid liberation of steam from the water as the mixture flows through said bank. Owing to its greater density, the water tends to lag behind the steam where the latter is free to move upward. In the upright bank 6, the steam has such a freedom of movement and, as a consequence, it separates rapidly from the lagging water and enters the drum 3 accompanied by comparatively little moisture. Furthermore, the position of the bank 6 facilitates the imparting of heat thereto by the gases of combustion as directed by the s stem of baflling hereinafter explained.

majority of the tubes of the bank 6 dis charge into the drum 3 above or near the water level in said drum, causing little disturbance of the water therein and thereby leaving the steam in the drum more nearly dry than would otherwise be the case. In the drum an approximate water level, as at 11, is maintained as indicated by water column 12 so that steam disengaged into this drum is separated from the water itself which descends through the bank 7 to the drum 1, thereby completing the cycle of flow of water andsteam through the drums and banks of tubes.

Therefore, by this definite arrangement of drums and tubes, a positive yigorous flow or circulation of water and steam through the tubes (corresponding to heating surface) is obtained, producing a large volume of steam for each unit of heating surface. This circulation is unrestricted, since the combined cross-sectional area of each bank of tubes is equal to the similar areas of the other banks, and the drum areas are proportioned to provide liberal disengaging surfaces. This arrangement promotes highly efficient continuous rates of boiler operation, in case of overload, without detriment; it causes rapid positive unrestricted circulation; eliminates the possibility of reversal 'of circulation should the steam ressure suddenly drop from excessive service use; and, generates an extremely dry steam through a regular cycle, as well as freeing it of moisture.

This infinite relation of drums and banks of tubes lends itself to an improvement in bafiling that forms part of the present invention. As shown in Figs. 1 and 2, the boiler is fired by a forced draft underfeed stoker 42, the ibafllin described hereinafter being particularly adapted to that type of stoker, since such stokers produce high furnace temperatures. The arrangement is also adapted to other types of stokers and also to hand-firing with grates or furnaces and is not limited to the ty e of stoker shown. The arrangement is s own with a superheater which will be described hereinafter.

In the formation of the baflling shown particularly in Fig. 1, a set of battle tile 13 is supported on the first bank of tubes 5 from the drum 1 up to and just under the superheaters lower header 25. 'Another set of bafile tile 14 is supported on the superheater tubes 24, which are bent to parallel in a general 'way the direction of the

tubes

5 and 6. The set 14 forms a continuation of the set 13 and extends from the lower header 25 along the tubes 24 past the header 23 into the bend at the upper end of the tubes 24. A capping set of tile 15 rests on the top of the superheater tubes and overlaps the upper edge of the set 14. The set 15 is held in place by the clamps 16 engaging tubes of the bank 6. The set 15 is spaced below the drum 3 to rovide a baffle opening in the setting. The bailiing, formed of the

sets

13, 14, 15, serves to direct the furnace gases along the banks of

tubes

5 and 6 and the superheater tubes 24. Pyrometer openings 19 are provided in the wall of the furnace so that temperatures can be determined at the principal positions of gas passage.

The relation of drums and banks of tubes is particularly advantageous in positioning the baffle and its openings since

sets

13, 14, 15 are supported on the tubes without the aid of structural cast-iron or other supports which general] fail with high temperatures and cause ad itional maintenance expense and loss of time for repairs.

The inclination of the bank 6 determines the minimum bailie opening between bailie 14 and drum 2, but the baflle opening between the baflie 14 and the drum 3 maybe h determined by baflle 15 with a superheater to meet diil'erent requirements. The gas travel, as determined by the baiiiing and furnace walls, is generally arallel to the banks of tubes and fully envel ops the latter, the bathing. considering its simplicity, causes much less draft loss through the setting, which is a considerable advantage as there is a saving in stack work. The bathing and arrangement of tube banks further obviate settling of dust on the tubes and surfaces to affect heat transmission, and thereby facilitate higher efficiency in operation. Also, an advantage is secured by a downward flow of the gases over the rear bank of tubes, as less soot or dust will collect either on the tubes or on the upper portion of the bottom drum. being deposited by gravity in the dust chamber back of the bridge-wall.

As shown in Fig. 2 the tubes are spaced in alternately wide and narrow rows in a well known manner, thereby allowing easy removal of an tube without disturbin the others. All the tubes, except those 0 the superheater, are preferably bent to the same radius to simplify construction.

An improved water and steam separator is provided for the drum 3. This consists of a sectional partition 20 placed in each end of the drum just outside of the last row of tubes, and a dry pipe 21 leads from the chambers formed between the partitions and the ends of the drum. The dry ipe leads to the steam outlet pipes 22. ach partition extends across the drum with a clearance above and below the same, extending downward in the drum below the water level 11 therein. This arran ement causes steam discharged into the" rum by the tubes in bank 6 to flow overthe partitions into the chambers in the ends of the drum to enter the dry pipe 21. The clearance between the lower edges of thepartitions and the bottom of the drums permits water to flow beneath the partitions to the ends of the drum and thereb form a larger water reserve without raising the normal level, and this decreases fluctuations under steam demand. The space below the partitions also permits the washin out of the drum throughout itsentire iingth. The top drum 3 may be provided with a manhole 26 (Fig. 2) at either end to facilitate cleanin of the drum. As the partitions are sectiona and removable, they can be easily displaced for purposes of cleaning and inspection. The top drum is also provided with safety valves 27 in the usual manner.

The relation of drums and banks of tubes provides an advantageous arrangement for a superheater. As shown in igs. 1, 2 and 3, the steam passes from drum 3 through dry pipe 21 and outlet pipe 22 outside of t e furnace setting to the upper superheater header 23, through which the steam is distributed through a plurality of superheater tubes 24 to be superheated and discharged into the lower superheater header 25 and thence to the main steam connection for service. The

superheater headers

23 and 25 are supported at each end by brackets (not shown) attached to the supporting frame of the boiler, and are provided with the usual key caps (not shown) ito permit expanding any tube end or removing a tube without interfering with other tubes, and any superheater tube may be removed and passed between the boiler tubes proper and out of the furnace setting in the usual manner. The superheater headers are protected from the direct path of the. furnace gases by the bafiiing heater tubes 24 are Eroperly in the path of the second pass of t e urnace gases, thereby being so located as to give the best operating results. The length of the superheater tubes or the number used may be 13-14, While the supergoverned by the degrees of superheat desired. To relieve an usual condition where Water might condense or collect in the upper header 23, a suitable drain (not shown) can be provided in the bottom of the same.

The relation of drums and banks of tubes permits the use of an improved su porting frame. Referring to Figs. 1 an 2, this frame comprises

columns

28, 29, 30 and 31. supporting beams 32 for the top drum 3, and supporting beams 33 for the bottom drum 1, the frame being braced by the horizontal members 34 as shown. The supporting frame is so desi ed that the drums, tubes and parts of t e boiler proper may be erected independently of the brick furnace setting described hereinafter. The top drum 3 is fixed, being rigidly supported in any suitable way, as by brackets (not shown), on the supporting beams 32. The bottom drum 1 is sup orted on brackets (not shown) preferab y resting on rollers (not shown) carried by the beams 33, therebv providin for easy compensating movement of the rum horizontally backiward and forward. The supporting brackets for the drums and the rollers are of the usual con struction and form no part of the present invention. Drum 2 is entirely suspended by the

tube banks

5 and 6 and is free to move. ,This supporting frame-most advantageously compensates for the expansion of the boiler proper without producing any expansive strains. The top drum being fixed is an advantage since the steam outlet connects with the same. The top drum being fixed and the bottonrdrum free to move horizontally permits the suspended frbnt drum to move freely in any resultant direction without producing expansive strains or interfering with the bricksetting. The members 34 give rigidity to the supporting columns and act as binders for the brickwork and thereby prevent cracks in the brick walls. The stack uptake, or breeching, is supported by transverse members 35 carried by the lower hori zontal bracing members 34. This provides for the stack asupport on a relatively low part of the structure and hence minimizes vibration in the framework and brick-setting whioh might result from wind strains on the stack. It is to be observed that the weight of the stack is carried by the rearward columns of the supporting frame and that these columns carry in addition but about onethird of the weight of the boiler proper and its liquid content, while the forward columns carry the other two thirds of the wei ht of theboiler. In this way a balance distribution of the load of the boiler and stack on the supporting frame is obtained.

The defined relation of the drums and tube banks, together with the supporting.

frame, provides for certain improvements m the furnace-setting. As shown in Figs. 1 and 2, the boiler front 37 may have its lower part arranged for stoker, hand or other forms of furnace firing. The lower front wall 38 of the setting is capped off with tile to protect the front drum 2. The upper front wan 39 has a series of tile effecting a seal over the front drum 2. The top drum 3, the upper end of the front bank of tubes 6 and the rear bank of tubes 7 may be covered with brick and mixtures of insulating cement and mortar or other insulation. The brick and insulation are free to expand and move with the supporting tubes, there being provided an expansion joint at the stack and inner supporting member 35. The side walls 40 are of regular construction, as shown by reference to the transverse section in Fig. 2, except that a very important saving is effected in the quantity of brickwork required for both side walls and also the rear wall 41. In comparison with Watertube boilers of that type which require a rectangular form of setting, it is found that, for a given size or horse power, the saving in brickwork in the present invention is a very substantial amount. By reference again to Fig. 1, it is apparent that the saving in side walls, above and to the left of the rear inclined bank of tubes 7, and likewise in the corresponding low rear wall, is effected without being detrimental to the design or function of the furnace chamber. furnace gas passages or rear dust chamber. My setting has a distinct advantage since the comparatively low rear wall, where the stack is supported, is much less liable to crack from strain clue to stack vibration and expansive strains in the brickwork than is a comparatively high wall under the same con ditions. The setting is easily accessible inside through usual cleaning and inspection doors (not shown) and the tubes and other parts may be readily inspected and repaired without inconvenience.

In Fig. 3 is shown a modified form of the boiler and setting. The relative positions of the drum and banks of tubes is maintained as in the first instance, but more tubes are employed in bank 5 and the number of tubes in either of the other banks may be changed if desired. In this modification, another set of battles 17 is introduced to deflect the furnace gases on the first pass toward the drum 1 and thence toward drum 2. As the exit of the furnace gases is to an underground flue, causing downward passage over drum 1, additional baffle tile 18 is introduced to direct the descending gases along the bank 7 so as to fully envelop the same. By placin baflle 17 above the second row (on the third row if desired) of tubes in bank 5, a lower furnace temperature can be obtained than would be obtained by placing this baffle over the first row of tubes. The baflling arrangement in this modification is particularly adapted to furnace conditlons involving high temperature as attained by mechanical stokers, but the arrangement is not limited to such stokers. The furnacechamber may be of such design as will suit various fuels or methods of firing, and likewise the exit of damper-controlled gases may be to an underground flue, as shown, or through the rear wall or to a stack above the rear wall, or otherwise, as desired.

In the modification shown in Fig. 3, a different form of setting over the bank 7 is employed, which consists of a combination 43 of fire tile and refractory brick supported independently "of the tubes by metal framework. This framework, as shown, consists of short transverse lengths of cast-iron Ts suspended from longitudinally disposed structural steel shapes. Where the boiler is subject to intermittent loads of various ratings. such design will tend to lengthen the life of the refractory covering for bank 7. In this modification, the superheater 24 may be omitted if desired and steam used for service from the outlet 22. The supporting framework is substantially the same as in Fig. 1.

In Fig. 4 is shown, somewhat diagrammatically, another modification of the boiler and setting. The relative positions of the drums and banks of tubes are maintained and the principles of water and steam circulation remain the same. The superheater has been omitted and the baffling 14 mounted on the tubes of the

banks

5 and 6 as shown. The baffling so mounted affords the same advantages as the baffling described in connection with Fi 1. The passage of furnace gases between t e baffles and drums may be restricted to meet the requirements. The supporting frame is the same as in Fig. 1. The boiler of this modification is especially adapted to an improvement in the furnace chamber, as will be understood from the following:

Fig. 4 shows a furnace arrangement for burning gas or oil. or fuel admitted in a state of fine separation. A burner 44 is introduced through the rear wall and a refractory furnace chamber 45 is provided that directs the burning fuel in a generally horizontal direction, whence it rises and envelops the tubes and passes along in the regular manner. This method affords an advantageous settlement of dust in the combustion chamber 46 before reaching the tubes. as in the case of blast furnace gas. It also affords almost complete admixture with the air and complete combustion before entering the tube banks or passages between the same. The form Or shape of the refractory arches comprising the furnace chamber 'may be changed to suit the kind of fuel and burne used.

A fiirther modification of the invention is shown in Fi 5, and it pertains to means for disengaging and heating the steam and a change in the construction of the setting for the front walls to meet different requirements.

Referring to Fig. 5, the relative position of the main drums and the tube banks are maintained and the principles of water and steam circulation remain the same as in the preceding instances. A baffling 14 is employed similar to that previously described in regard to Flg. 4. The modification consists in employing a plurality of tubes 8 connectin drum 3 with an additional or auxiliary rum 4 located below and slightly in front of said drum 3; further, a furnace front wall 47 separated by drum 4 from the independent upper front wall 48 supported on framing 49.

In drum 3 the separator partitions and dry ipe are omitted as the steam is release from the upper portion of said drum throu h the row of tubes 8. In passing from rum 3 to drum 4 the steam travels sufficient distance through tubes 8 to be further heated and relieved of moisture. Therefore, drum 4 is a dry-steam drum, without water held therein, and from this drum steam is released for service. However, this arrangement may be used in conjunction with a superheater as shown in Fig. 1, the superheater being connected to drum '4. Thedrum 4 is made sufficiently large to permit a man to enter the same for cleaning purposes; however, a header type may be employed, similar to the

superheater headers

23 and 25 previously described in connection with the showing in Fig. 1 should it be so desired. The qualit o steam produced by the employment 0 the additional or auxiliary drum 4 is greatly improved by the increase in its temperature and dryness.

The front furnace wall 47 is especially arranged so as to by-pass a portion of the furnace gases partially through the bank of tubes 5 and under drum 2 and upward around tubes 8, as indicated by the gas travel arrows. In this arrangement, the drum 4 is positioned between the upper part of wall 47 and the lower part of wall 48, the lower wall being inset from the upper wall for the purpose. The wall 47 may be designed so as to limit the quantity of gas by-passed, thereby controlling the temperature of said gases passin over tubes 8,

which would be beneficialln using various fuelsend also different furnace conditions. Gases tllIGCt from the furnace, passing over tubes 8 conveying steam without water, might be detrimental by causing the tubes eventually to burn.

The arrangement of wall 47 promotes a better operating condition by admitting over tubes 8 gases reduced in temperature but relatively hotter than gases passing through tube bank 6, et not sufiiciently hot to be detrimental. his construction also removes drum 4 from direct exposure to the furnace gases and ermits free expansion of the lower wall 4 without affecting the upper wall 48. Likewise, the lower wall 47 may be repaired 0rrenewed without affecting the upperwall 48. The upper wall 48 is supported independently of the lower wall 47 on framing 49 and is free to expand and likewise closes the setting with the drum 4 and the lower wall.

What is claimed is: I

1. A steam-boiler comprising transverse mud, water and steam drums in series communication throughv interposed banks of tubes, said drums bein in trian lar arrangement with the mu drum positioned to the rear and below the horizontal level of the water drum and the steam drum positioned above the water drum in approximately vertical alinement therewith.

2. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular arran ment with the mud drum ositioned to t e rear and slightly below the orizontal level of the water drum and the steam drum positioned above the water drum in approximately vertical alinement therewit the distance between the mud and water drums being in close approximation to the distance between the water and steam drums. 3. A steamboiler comprising transverse mud, water and steam drums in series communlcation through interposed banks of tubes, said drums being in triangular arrangement with the mud drum positioned to the rear and slightly below the horizontal level of the water drum andthe steam drum positioned above the water drum in approximately vertical alinement therewith, the distance between the mud and water drums being slightly in excess of the distance between the water and steam drums.

4. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular arrangement with the steam drum uppermost and the mud drum lowermost, this relative arrangement of the drums and banks of tubes being such that the bank of tubes leading from the mud drum to the water drum extends in a direction that is inclined upwardlv from the horizontal at an acute angle and the bank of tubes leading from the water drum to the steam drum extends approximately in a vertical direction.

5. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular arrangement with the steam drum uppermost and the mud drum lowermost, the relative arrangement of the drums and banks of tubes being such that the bank of tubes leading from the water drum'to the steam drum extends approximately in a vertical direction and the bank of tubes leading from the mud drum to the water drum extends at an obtuse angle to the direction of the bank of tubes connecting the water and steam drums.

6. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular or rangement with the steam drum uppermost and the mud drum lowermost, the relative arrangement of the drums and banks of tubes being such that the bank of tubes leading from the mud drum to the water drum extends in a direction that is inclined .u wardly from the horizontal at an acute angle and the bank of tubes leading from the water drum to the steam drum extends approximately in a vertical direction, the length of the bank of tubes connecting the mud and water drums being approximately the same as the length of the bank of tubes connecting the water and steam drums.

7. A steam-boiler comprising transverse mud, water and steam drums in 'series communication through interposed banks of tubes, said drums being in triangular arrangement with the steam drum uppermost and the. mud drum lowerm0st,-the relative arrangement of the drums and banks of tubes being such that the bank of tubes leading from the water drum to the steam drum extends approximately in a vertical direction and the bank of tubes leading from the mud drum to the water drum extends at an obtuse angle to the direction of the bank of tubes connecting the water and steam drums, the length of the bank of tubes connecting the mud and water drums being approximately the same as'the length of the bank of tubes connecting the water and steam drums.

8. A steam-boiler comprising transverse mud. water and steam drums in seriescommunication through interposed banks of tubes, said drums being in triangular arrangement with the steam drum uppermost and the mud drum lowermost, the relative arrangement of the drums and banks of tubes being such that the bank of tubes leading from the water drum to the steam drum extends approximately in a vertical direction and t e bank of tubes leading from the mud drum to the water drum extends in a direction that is at an obtuse angleto the direction of the bank of tubes connecting the water and steam drums, the length of the bank of tubes connecting the mud and water drums being slightly longer than the bank of tubes connecting the water and steam drums.

9. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular arrangement with the steam drum positioned approximately vertically above the water drum and with the mud drum positioned to the rear of and lower than the water drum.

10. In a steam-boiler, the combination of a furnace setting with a circulating system mounted thereincom-prising transverse mud, Water and steam drums in series communica tion through interposed banks of tubes. said drums being in triangular arrangement with the mud drum lowermost in the rear part of the furnace chamber and the water and steam drums in the front part of the chamher, the steam drum being placed approximately vertically above the water drum, and bafiling mounted in the furnace chamber to direct the furnace gases successively around the banks of tubes successively connecting the drums.

11. In a steam-boiler, the combination of a furnace setting with a circulating system mounted therein comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular arrangement with the banks of tubes connecting the mud and water drums inclined upwardly across the fire-chamber from the mud drum located in the rear of the furnace chamber to the water drum located in the front of the furnace chamber and with the bank of tubes connecting the water and steam drums extending approximately vertically upward from the water drum to the steam drum located in the upper part of the furnace chamber, and bafiiing mounted in the furnace chamber to direct the gases from the fire-chamber successivelyaround the banks of tubes connecting the drums.

12. In a steam-boiler, the combination of a furnace setting, with a circulating system mounted therein comprising transverse mud, water and steam drums in series communication through a first bank of tubes connecting the mud and water drums, a second bank of tubes'connecting the water and steam drums and a third bank of tubes connecting the steam and mud drums; said drums being in triangular arrangement with the mud drum lowermost in the rear part of the furnace chamber and the steam drum uppermost in the front part of the furnace chamber; said first bank of tubes being inclined upwardly over the fire-chamber from the mud drum to the water drum in the front part of the furnace chamber and said second bank extending approximately vertically from the water drum to the-steam drum, and said third bank of tubes extending downwardly from the steam drum to the mud drum; and a baffling mounted in the furnace chamber for directing the furnace gases to successively envelop the first, second and third banks of tubes.

13. In a steam-boiler, the combination of a furnace setting with a circulating system mounted therein comprising transverse mud, water and steam drums in series communication through a first bank of tubes connecting the mud and water drums, a second bank of tubes connecting the water and steam drums and a third bank of tubes connecting the steam and mud drums; said drums be ing in triangular arrangement with the mud drum lowermost in the rear part of the furnace chamber and the steam drum u permost in the front part of the furnace 0 amber; said first bank of tubes being inclined upwardly over the fire-chamber from the mud drum to the water drum in the front part of the furnace chamber and said second bank extending approximately vertically from the water drum to the steam drum, and said third bank of tubes extending downwardly from the steam drum to the mud drum; and a batlling mounted in the furnace chamber to extend from the mud drum, partly over the first bank of tubes and partly along the second bank of tubes to within a short distance of the steam drum to guide the furnace gases to successively envelop the first. second and third banks of tubes.

14. In a steam-boiler, the combination of a furnace setting with a circulating system mounted therein comprising transverse mud, waterand steam drums in series communication through a first bank of tubes connecting the mud and water drums, a second bank of tubes connecting the water and steam drums and a third bank of tubes connecting the steam and mud drums; said drums being in triangular arrangement with the mud drum lowermost in the rear part of the furnace chamber and the steam drum uppermost in the front art of the furnace chamber; said first ban of tubes being in clined upwardly over the fire-chamber from the mud drum to the water drum in the front part of the furnace chamber and said second bank extending approximately vertically from the water drum to thesteam drum, and said third bank of tubes extendin downwardly from the steam drum to t e mud drum; a superheater communicatin with the steam drum and mounted in the Furnace chamber having tubes following the general direction of the first and second banks of tubes; and a baffling mounted in the furnace chamber to guide the furnace gases to sues v cessively envelop the first and second banks of tubes, together with the superheater tubes, and the third bank of tubes.

15. In a steam-boiler, the combination of a furnace setting with a circulating system mounted therein comprising transverse mud, water and steam drums in series communication through a first bank of tubes connecting the mud and water drums, a second bank of tubes connecting the water and steam drums and a third bank of tubes connecting the steam and mud drums; said drums being in triangular arrangement with the mud drum lowermost in the rear part of the furnace chamber and the steam drum uppermost in the front part of the furnace chamber; said first bank of tubes being inclined upwardly over the fire-chamber from the mud drum to the water drum in the front part of the furnace chamber and said second bank extending approximately vertically from the water drum to the steam drum, and said third bank of tubes extending downwardly from the steam drum to the mud drum; a superheater communicating with the steam drum and mounted in the furnace chamber having tubes following the general direction of the first and second banks of tubes; and a baffling carried by the first bank of tubes and the tubes of the superheater to guide the furnace gases to successively envelop the first and second banks of tubes, together with the superheater tubes, and the third bank of tubes.

16. In a steam-boiler, the combination of a furnace setting with a circulating system comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, said drums being in triangular arrangement with the steam drum positioned in the upper part of the furnace chamber approximately vertically above the w ter drum and with the mud drum positioned in the rear part of the furnace chamber and somewhat lower than the water drum, a baffling mounted in the furnace chamber to guide the furnace gases to successively envelop the banks of tubes, and a superheater communicating with the steam drum mounted in the furnace and having tubes extending approximately parallel with and adjacent to one of the banks of tubes to be enveloped by the furnace gases directed by the baffling to said adjacent bank of tubes.

17 A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, in combination with a supporting frame, said drums being in triangular arrangement with the mud drum and the steam drum supported by said frame and the water drum suspended by the banks of tubes conand mud drums.

18. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes, in combination with a supporting frame, said drums being in triangular ar rangement with the mud drum supported by said frame to the rear and slightly below the horizontal level of the water drum and the steam drum supported by said frame approximately vertically above the water drum, and the water drum being suspended by the banks of tubes connecting said water drum with the steam and mud drums to permit free expansion of said drums and the interposed banks of tubes.

19. A steam-boiler comprising a supporting frame, a steam drum rigidly secured thereto, a mud drum yieldingly supported by the frame, a water drum, banks of tubes connecting said three drums in series communication, said water drum being suspended by the banks of tubes connecting it with the mud drum and the steam drum respectively.

20. A steam-boiler comprising transverse mud, water and steam drums in series communication through inter sed banks of tubes, in combination wit a supporting frame and a furnace setting or casing, said drums bein in triangular arrangement with the mud r rum supported by said frame in the rear part of the furnace casing slightly below the horizontal level of the water drum positioned in the front part of the furnace casing and the steam drum supported by said frame approximately vertically above the water drum in the upper part of the furnace casing, said mud and steam drums being carried by the supporting frame independently of the furnace casing and the water drum being suspended by the banks of tubes connecting said water drum with the steam and mud drums to permit free expansion of said drums and interposed banks of tubes relatively to each other and relatively to the furnace casing.

21. A steam-boiler comprising transverse mud, water and steam drums in series communication through interposed banks of tubes to form the circulating system, in combination with as upporting frame and a furnace setting or casing, said drums being in triangular arrangement with the mud drum supported by the frame below the horizontal level of the water drum and the steam drum supported by said frame approximately vertically above the water drum in the upper part of the furnace casing with the water drum suspended fromthe steam drum by the interposed bank of tubes and a stack communication with the interior of the furnace casing carried by the rear part of the supporting frame. a

22. A steam-boiler comprising three main transverse drums in series communication through interposed banks of tubes, in combination with a supporting frame and a furnace setting or casing, said drums being in triangular arrangement with two of the drums in a proximately vertical alinement carried by tlie supporting frame in the front part of the furnace casing and the third drum carried by the supporting frame in the rear part of the furnace casing slightly below the horizontal level of the lower front drum so that the bank of tubes connecting the upper front drum with the rear drum is rearwardly declined, said furnace casing having a comparatively high front wall and a comparatively low rear wall and having side walls with their upper edges declined toward the rear to follow the declination of the bank of tubes connecting the front top drum with the rear drum, and an inclined covering for the last mentioned bank of tubes.

23. A steam-boiler comprising three main transverse drums in series communication through interposed banks of tubes, in combination with a furnace setting or casing, said drums being in triangular arrangement with two of the drums mounted in the front of the furnace casin in approximately vertical alinement and t e third drum mounted in the rear part of the furnace casing slight- 1 below the horizontal level of the lower ront drum so that the bank of tubes connecting the upper front drum with the rear drum will be rearwardly declined, said furnace casing having a comparatively high front wall and a comparatively low rear wall aiid an inclined covering for the last mentioned bank of tubes.

24. A steam-boiler comprising three main transverse drums in series communication through interposed banks of tubes, in combination with a furnace setting or casin said drums being in triangular arrangement with two of the drums mounted in the front of the furnace casing in approximately vertical alinement and the third drum mounted in the rear part of the furnace casing slightly below the horizontal level of the lower front drum so that the bank of tubes connecting the upper front drum with the rear drum will be rearwardly declined, said furnace casing having a comparatively high front wall and a comparatively low rear wall, a stack communicating with the furnace chamber supported adjacent the low rear wall of the furnace casing, and a covering carried by the bank of tubes connecting the upper front drum with the rear drum, said covering bein movable at its lower ed e relatively to tie stack to accommodate t e expansive movement of its supporting bank of tubes.

25. A steam-boiler comprising three main transverse drums in series communication through interposed banks of tubes, in combination with a furnace setting or casing comprising a comparatively high front wall and a comparatively low rear wall and side walls inclined at the upper edges from the top of the front wall to the top of the rear wall, said drums being in triangular arrangement with two of the drums mounted one above and adjacent to the front wall of the furnace casing and the third drum mounted adjacent the rear wall of the furnace casing slightly below the horizontal level of the lower front drum, the bank of tubes connecting the uper front drum with the rear drum in paral- Eel relation to the inclined upper edges of the side walls of the furnace casing, and a covering for the last mentioned bank of tubes in parallel relation thereto.

In testimony whereof I have signed this specification.

PAUL WRIGHT.

Ccrtlflcatc of Correction.

It is hereby certified that in Letters Patent No. 1,437,790, granted December 5, 1922, upon the application of Paul Wright, of Birmingham, Alabama, for an improvement in Boilers, an error appears in the printed specification requiring correction as follows: Page 2, line 120, for the word infinite read definite; and

that, the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 16th day of January, A. D., 1923.

[mu] KARL FENNING,

Acting Commissioner of Patents.