US2070250A - Boiler construction - Google Patents

Description

Feb. 9,A 1937. J. P. BADENHAUSEN BOLLER CONSTRUCTION Filed Sept. 5, 1935 3 Sheets-Sheet 1 INvEN-ro/v zz. y

'il if" WITNESS HTTO RNEf Fell)B 9, 1937. .1. P. BADENHAUSEN BoILER CONSTRUCTION Filed Sept. 5, 1935A 5 Sheets-Sheet 2 Patented Feb. 9, 1937 UNITED Is'r-.frias lPA'rEN'rA OFFICE BOILER CONSTRUCTION John Phillips Badenhausen, Philadelphia, Pa., assigner of one-half to Day and Zimmermann, Incorporated, Philadelphia, Pa., .a corporation of Maryland Application September 5, 41935, Serial No. 39,254 claims.- (cL' 12e-47s) like, it has been rather common to try to utilize the steam generating designs of ordinary boiler construction and to add thereto provisions for u cooling the walls of the combustion chamber and for discharging the steam and hot water from the cooling walls-directly 'into the circulatory system of the steam generating section; the resuit of thishas been to make the completed structure increasingly higher, as the capacity of the boiler was increased, thereby making the boilers occupy too much valuable space. There has not beenwery much of an endeavor manifested to completely re-design a steam generator for use with such fuels without reference to standard boilers, designed to burn ordinary coal.

The object of the present invention is to simplify the design of boilers using finely divided fuels, by providing thesteam-generating section thereof,l with. merely one large steam and water drum, withtwo -relatively small headers and with as few water tubesas possiblel connecting said drum and headers.

A further object of this invention is to provide a construction lwhereby the gases of combustion,

reaching the superheater, are of relatively higher temperature than they are in boilers, as heretofore constructed, thereby enabling me to reduce the heating' surfaces of the superheater and with o' that the cost of the same.

A further object of this invention is to provide a construction which will make the over-all height and also the depth of the boilerconsiderably less than the corresponding dimensions of a boiler of equal capacityas constructed up tothe present time. l

A further object of this invention is to make possible the placement of an air heater or economizer, or both, withinthe space heretofore occupied bythe large mud drum and the large bank of downcomer tubes connecting the mud drum with the steam-and-water drum with which boilers of this type have been heretofore provided.

A further object of this invention isvto utilize an economizer as an active part of the main heating surfaces of the boiler thereby substituting the verycompact arrangement of economizer tubes with its f/great` heat absorptive proper-v ties for the relatively widely spaced aggregations of tubes heretofore employed, thereby utilizing v comers.

the greater heat-absorptionl properties of the economizer, over that of the ordinary boiler tubes in the steam-generating section.

The heating surfaces of the ordinary boiler or steam generator is divided into upcomers and downcomers. Since water in the heating surfaces, absorbing heat, will tend to rise naturally and since the heating 'of the upcomer tubes in- `creases the upward rise of the water therein, it

follows that the heating of the downcomers tends to retard the downward flow in the down- This, therefore, results in an unequal circulation of the water,.which will be faster in the upcomers than in the downcomers and this may result in the failure of the water to move in certain of the tubes with a consequent overheating `and sagging of some of the tubes. 'I'he' natural ow ofthe water in the tubes should always be upward and the downcomers should be subjected, if possible, to a minimum exposure to the gas flow, or to a minimum heating surface in the boiler gases. The greater the heat of the water in the boiler the faster will be the velocity of the circulation in the upcomers. All of this tends to disturb the proper circulation of water within the steam generating section.

A further objectv of the present invention is, therefore, to provide a construction for the free,

` unimpeded circulation of the water in the steamgenerating section of the boiler and in the water walls, from the bottom of the structure toward' the steam-and-water drum, by' shielding the downcomers as much as possible from the radiant heat of the combustion chamber and by supplying the coolest water in the boiler to the steam ygenerating section and to the wall cooling at points near the bottom ofthe boiler structure, whence it freely circulates upwardly throughout the tubes. h

Other objects of my invention will appear in the specication and claims below. A,

In the drawings forming a part of this speciiication and in which like reference characters drum, the intermediate header, the lower header and the upper header of the cooling section of a side wall of a boiler, to clearly indicate the connetions of the banks of tubes thereto.

Referring now particularly to Fig. 1, the boiler comprises a steam-and-water drum A, a relatively small intermediate header B and a relatively small lower header C. The intermediate header B is connected to the steam-and-water drum A by two banks D and E of tubes and the steam-and-water drum A is. connected with the lower header C by a bank F of downcomer tubes, which is entirely shielded from the radiant heat of the combustion chamber by the baille G and the rear wall H of the furnace.

The intermediate header B and the lower header C are connected by a relatively small double bank I of steam-generator tubes.

It will thus be seen that the circulation of the water in the steam-generating section of the boiler is continually upwardly in the banks D, E and in the bank I of tubes, the downcomer bank F being completely shielded from the radiant heat of the combustion chamber, and located in that portion of the boiler where the gases of combustion are comparatively cool.

Only one of the side walls J is shown in the drawings, it being understood that both side walls of the boiler are substantially alike. Each is water-cooled bya bank K of tubes extending vertically and close to the wall, the opposite ends of the bank being connected respectively to the upper side-wall header L and to the lower sidewall header M. The lower header M is connected to the lower boiler header C by a set of tubesm outside of the side wall J, by which they are shielded from the radiant heat of the combustion chamber. Each of the upper side wall headers L is connected by a bank of tubes N with the steam-and-water drum A at the end of the drum beyond1 and beside the banks D and E of the generator section of the boiler, and on the inner surface of the side wall which is water cooled thereby.

The rear wall H and the bafe G are water cooled by two banks O and P of risers extending upwardly adjacent thereto and extending from the lower header C directly to the steam-andwater drum A, the banks passing through the upper portion of the bafe G. The bank O lies behind but on the outer side of the wall H, but

passes through it at the top thereof and lies on the inner side of the baille G, and the bank P lies on the inner side of the wall H and on the inner side of the baille G. Both said banks are thus exposed to the radiant heat of the combustion chamber.

The economizer Q which may be of standard construction, is preferably within the boiler beneath the steam-and-water drum A. It occupies the space usually occupied by the large bank of downcomer tubes heretofore employed in a water circulating type of steam generator. Gases of combustion, after passing from the combustion chamber and over the banks of steam-generating tubes D, Ey are conducted into the upper end of the economizer Q which presents a much greater capacity for absorbing the heat from the gases than the loose congregation of steam generating tubes heretofore utilized in boiler construction. The lower end of the economizer communicates directly with the lower end of the air heater R (of usual construction) in which the air forced into the upper end of the heater R is heated and conveyed therefrom by the air conduit S to the pulverized fuel burners T.

Feed water is introduced into the lower end of the economizer by the pipe U and the heated' steaming water therefrom is delivered bya bank V of tubes communicating with the underside of the steam-and-water drum A, whence it passes to the bank F of downcomers communicating respectively with the lower header C, the lowest point in the generating section, the lowest point of the banks O and P of risers, and to the lowest headers M of the side wall banks K through tubes m.

It is here to be observed that this arrangement of the banks of steam-generator and wall cooling tubes is of particular advantage in enabling me to locate and install the superheater W in substantially the hottest part of the boiler immediately over the staggered small bank I of generator tubes. This enables me to reduce to a minimum, the heating surface of the tubes of the superheater, and to thus substantially reduce the cost of construction. The superheater W may be connected to the steam space of the steam-and-water drum A by a pipe X, and the superheated steam may be delivered from the superheater by the pipe Y.

Referring now to the development of the surfaces of the steam-and-water drum A, the head# ers B, C and the side wall upper header L as shown in Fig. 4, it will be seen that by staggering the upper ends of the banks D and E of the steam-generating section, where they are connected to the steam-and-water drum A greater space may be provided between the circumferential rows of holes in the steam-and-water drums than is provided in ordinary steam-generator construction, thereby substantially increasing the ligature strength of the drum to adapt it to the high pressures now availed of in boilers of this type, and without increasinga the thickness of the wall of said drum.

The tubes of the various banks of tubes are designated in Fig. 4 by lower case letters corresponding to the capital letters heretofore employed in referring to the banks as a whole. The points of attachment of the tubes to the steamand-water drum A, to the intermediate header B, the lower header C and to the top side wall header M are clearly indicated. The tubes d1 to d4, of bank D are disposed in a row extending circumferentially of the drum A, connect, and are connected to the intermediate header B at d1, d2, d3, d4 respectively. The tubes el, e2, e3, e4, of the bank E are connected to the intermediate header B in a staggered relationship at e1, e2, e3, e4 respectively. The ligature strength of the small header B may be maintained by increasing the thickness of its wall.

The banks O and P of riser tubes o and p of the steam generator extend upwardly from the lower header C to the steam-andwater drum A are indicated as the pipes o and p in Fig. 4. They are preferably in a staggered relationship with respect to the drum A and with respect to the header C. The position of the bank F of shielded downcomer pipes f is indicated clearly in the developments of the surface of the drum A and lower header C. On the drum A (Fig. 4) is also indicated the positions of the pipes v1, 112, leading from the economizer Q. In Fig. 4 is also indicated the position of the pipes i1 and i2 of the bank I, extending from the header B to the header C. 'I'he position of the riser tubes o alternate with the downcomer tubes`F back of the wall H ber.

and are preferably staggered in their connections with the header C and drum A.

At the ends of the drum A is a row of tubes n1 to n comprising the bank N and indicated on the development of the drum A and of the header L, and the ligature strength of the drum A is thus retained.

It will be readily seen that the top wall Z of the combustion chamberis water-cooled by the upper tubes d1 of the bank D and by the upper tubes 11,1 of the bank N; that the side walls are cooled by the banks K and the banks N and that the rear wall and baffle are cooled by the riser tubes o, p, and by the downcomer pipesf and that the cooler water of the system is conducted from the steamand-water drum A through the bank F to the lower header C whencevit is distributed through the pipes or tubes mi, m2, m3, m4 to the lower side wall headers M and to the bank J of the steamgenerator section to the riser tubes o and p.

Thus in the circulatory system of the generator section and of the wall cooling section, thev direction of the flow of Water in all of the tubes except in the single `downwcomer bank F is upwardly. I'he large bank of the downcomer tubes, found in former constructions has been eliminated; the large mud drum of the old constructions has-also been eliminated; and space within the boiler walls is provided for the placement of the economizer, which most eiilciently abstracts the heat from the gases leaving the boiler and transfers it to the incoming feed water. The water, delivered from the economizer to the steam-and-water drum is at a high steaming temperature because of the reduction in the area of the heating surface of the tubes of the steam generating section. I have shown the front or fore wall Z1 of the furnace `chamber as being made of refractory material, but it is to be understood that this wallmay be water-cooled in like manner when so desired. i

Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States, is: A

1. In a boiler fory the combustion of nely divided fuel, the combination with a combustion chamber provided with a rearwall, of a relatively large steam-and-water drum at the top ofthe boiler in the rear portion thereof, a relatively small intermediate header at the front of the boiler and at a lowerlevel than said drum, a relatively small lower header at the bottom of 'said' boiler at the rear portion thereof, a relatively small bank of riser tubes exposed to the radiant heat in said combustion chamber and directly connecting said lower header with said intermediate header, a bank of riser tubes exposed to the radiant heat of said combustion chamber directly connecting said front header with said steam-and-water drum, a plurality of banks of riser tubes'extendlng upwardly along said rear wall and directly connecting said lower header with said drum, onefof said banks o! tubes having the lower portion shielded from the radiant heatof the combustion ,chamber by said rear wall and another of' said banks being shielded from the radiant heat at the upper portions thereof, and a relatively small bank of downcomer tubes directly connecting saidl steam-andwater drum with said lower header and shielded from the radiant heat of the combustion cham- 2. In a boiler for the combustion vided fuel, the combination with the combustion chamber of a steam generating section and a wall of iinely' dicooling section, said generating section comprising a large steam-and-water 'drum at the top of said boiler in the rear portion thereof, a relatively small intermediate header at the front of said boiler and at a lower level than said drum, a relatively small lower header at the bottom of said boiler at the rear portion thereof, a relatively small bank of riser tubes connecting said lower header with. said intermediate header, a bank of riser tubes connecting said intermediate header with said drum, and a relatively small bank of downcomer tubes connecting the lower side of said drum with said lower header and shielded from the direct radiant heat of said combustion chamber, said wall cooling section including a bank of `riser tubes substantially covering the rear wall of said combustion chamber, said riser tubes being shielded for portions ci their length and being connected at their upper ends directlyto said steam-and-water drum and connected at their lower ends directly to said lower header, said wall cooling section also including banks of riser tubes covering the side walls and having their upper ends connected to said steam-and-water drum and having their lower endsconnected to said lower header, wherevby the relatively cooler water delivered from said steam-and-water drum to said lower header, flows upwardly throughout the steam generating and throughout the wall cooling sections from the lowest part of said boiler back to said steam-and-water drum.

3. In a boiler for the combination of finely divided fuel and the like, the combination with a combustion chamber of a steam generating section, a wall cooling section, and an economizer section, said generating section including a relatively large steam-and-water drum in the top of the boiler at the rear thereof, a relatively small intermediate header at the front of said boiler at a lower level than the said drum, a relatively small lower mud header at the bottom of the said yboiler at therear portion thereof, a relatively small bank of riser tubes connecting said lower header with said intermediate header and having portions extending from the rear to the front in the upper portion of the combustion chamber, a bank of riser tubes connectirm said intermediate header with said 4steam-,and-water drum and havingportions shielded from the radiant heat of said combustion chamber; said wall cooling section including banks of riser tubes substantially covering the side walls of said combustion chamber, said riser tubes being connected at their upper ends to said Asteam-and-Water drum and connected at their lower ends with said lower header, said wall cooling section also including banks of riser tubes extending upwardly along the rear wall of said combustion chamber, said riser tubes being connected at their upper ends Vdirectly to said steam-and-water drum, and connected at their lowerends directly to said lower header and having portions shielded from the radiant heat o-f said combustion chainber, said economizer section being provided be-v neath said steam-and-water drum, and having riser 4tubes connected thereto, and a bank of downcomer tubes connecting said steam-andwater drum and said lower header and shielded from the -radiant heat of said combustion chamber.

v4. In a boiler for the combustion of finely divided fuel and the like, the combination with a combustion chamber'of a steam generating section, and a wall cooling section, said generating section including a relatively large steam-andwater drum in the top of the boiler at the rear thereof, a relatively small intermediate header at the front of. said boiler and below the level of the said drum, a relatively small lower mud header at the bottom of the said boiler at the rear portion thereof, a relatively small bank of riser tubes connecting said lower header with said intermediate header and extending from the rear to the front in the upper portion of the combustion chamber, a bank of riser tubes connecting said intermediate header with said steam-and-Water drum, said wall cooling section including banks of riser tubes substantially covering the side walls of said combustion chamber, said riser tubes being connected at their upper ends to the steam-and-water drum and connected at their lower ends with said lower header, said wall cooling section also includingbanks of riser tubes extending upwardly along the rear wall of said combustion chamber, said riser tubes being connected at their upper-ends directly to said steam-and-water drum, and connected at their lower ends directly to said lower header and having portions shielded from the radiant heat of said combustion chamber, and a bank of downcomer tubes connecting said steam-andwater drum and said lower header and shielded from the radiant heat of said combustion charnber.

5. In a boiler for the combustion of finely divided fuel and the like, the combination with a combustion chamber of a steam generating section, a wall cooling section, an economizer section and a superheater, said generating section including a relatively large steam-and-water drum in the top of the boiler at the rear thereof,

a relatively small intermediate header at the front of said boiler at a lower level than said drum, a relatively small lower mud header at the bottom of the said boiler at the rear portion thereof, a relatively small bank of staggered riser tubes connecting said lower header with said intermediate header, a bank of riser tubes connecting said intermediate header with said steam-and-water drum having portions shielded from the radiant heat of said combustion charnber, and a bank of downcomer tubes connecting the lower side of said steam-and-water drum with said lower header and shielded from the radiant heat of said combustion chamber, said wall cooling section including banks of riser tubes substantially covering the side walls of said combustion chamber, s aid riser tubes being connected at their upper ends to said steam-andwater drum and connected at their lower ends with said lower header, said wall cooling section also including banks of riser tubes extending upwardlyralong the rear wall vof said combustion chamber, said riser tubes being connected at their upper ends directly to said steam-and-water drum, and connected at their lower ends directly to said lower header and having portions shielded from the radiant heat of said combustion chamber, said economizer section being provided beneath said steam-and-Water drum and having riser tubes connected thereto, said superheater being relatively small and being positioned within said combustion chamber above the Vbank of riser tubes connecting the said headers

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