US1798653A - High-pressure-steam boiler - Google Patents

Description

March 3l, 1931.

Fig. Z

H. c. BJERING HIGH PRESS-URE STEAM BOILER Filed June 17, 1927 Patented Mar. 31, 1931 HANS CHRISTIAN BJERING, OF GJOVIK, NORWAY HIGHPRESSURE-STEAM BOILER Application led June 17, 1927, Serial No. 199,608,and in Germany January 25, 1927.

The present invention relates to high pressure steam boilers and particularly to the type of such boilers wherein the heating surface and also the water contents are small L6 in relation to the output. Therefore, the ordinary motion of the fiue gases past the steam generating elements by means of stack draught or by a blast at the air inlet will prevent the obtaining of a satisfactory efficiency.

10 Among other diiculties in such boiler plants should be mentioned the danger existing for accidents caused by a rupture in the boiler.

The purpose of the present invention is to avoid these inconveniences by a special arrangement of the course of the heat before it reaches the open air or the stack and also by a special construction of the boiler.

According to the invention I use as a fuel for the boiler a gas produced in a closed sys- 2 tem in the fire chamber of the boiler. For

I instancecombustible oils may be volatiliz'ed whereupon the obtained gas is mixed wlth air and is then passed into chambers or passages, wherein it is under pressure beneath a 2 5 `grate, the purpose of which is to distribute the combustible gas uniformly and directly to the steam generating elements and to prevent a back-throw or a return flow of the gases expanding during their combustion.

3o The grate should for this purpose be comi paratively thick and have a large area as compared with the apertures or slots passing therethrough.

surface of the grate, the volume of the gases of combustionwill highly increase, whereby a static pressure is created which, as a backthrow of the gases through the grate cannot take place, will result in the gases, being without any draught, forced forwards in the lire chamber, wherein the steam generating elements are arranged. On account of a sort of gas seal which the gases must'pass before reaching the outlet (stack), the heat within the fire chamber' will be distributed quite uniformly throughout the` heating surface of the boiler, and as a consequence thereof the gases will give olf the most possible heat to the boiler. lIn the lire chamber, in addition to the generating elements, may also be ar- During the combustion above or on the topranged a superheater, and in the seal, a preheater may be arranged which will be heated in the same uniform manner as the remaining parts of the boiler. l

`In this firing method the seal has tofuly fill four purposes, viz:

l'. To ensure a quite uniform heating of the whole boiler, whereby strains of material be-v tween its several parts or members and also dangers for leakages are avoided. It is a welllinown fact that high pressure boilers with small water contents are `much liable to get short of water and consequently to become red-hot, but as a consequence of the uniform heating all over in connection with the special construction, the vpresent boiler will be able tostand this taking place even under pressure.

2. To utilize the heat to the most possible degree for generation of steam, for superheating and for preheating purposes ask a cause of the gases of combustion being pressed against the seal and beingforced to fill up all free space before reaching the open air, so that the steam generating elements and the other members will be swept over bythev gases in a more 'eflicient manner than in case of any sort of draught.

To prevent unnecessary heat to escape through the stack when the fire is out of operation. This being very important in case the firing takes place with interruptions.

4. To reduce the corrosion of the boiler surface, because oxidizing air at the end of the firing operation is prevented from finding its in the form of narrowed pipes adapted to form a resistance to the outflow from the elements in case one of them should be subject toa rupture. Thereby the outiow through therupture will loseV its explosive character. In boilers of the kind referred to it is of great importance to avoid sediments of possible impurities. In the present case such sediments or mud collections on account of the peculiar arrangement of the boiler elements, will sink down and settle into a water header of a comparatively small diameter, wherefroin'they can be blown out inea-ns of the steam pressure. However, in order to prevent the impurities from burning "fast Within the header pipef'this pipe-should be so arranged that its underside is not subjected to the direct influence oftheifl-uegases.

All the purposes mentioned above are realized inthe present boiler construction illustrated in the annexed drawing.

Figurel is a yvertical section 'through' the fire chamber and one boiler element showing also steam and water headers arranged in accordance to the invention.

Figure 2 is a side elevation showing a numbei' of boiler :elements connected at top and bottom to headers .in thek manner indicated above.

Figure 3 is .a plan View of a portion -of a -group of boiler elements arranged side by side in one and the same plane.

Figure 4 is a `plan view vshowing aportion of a group of elements arranged side by side so as toform a ring.

Figure f5 is a .sectional plan view looking .down on the grate in Figure 1. y

In the drawing, 1 denotes the brickwork, 2 Athe fire chamber, into which thefcombustible mixture of gasi-fied fuel and lair is'introduced by a suitably high pressure beneath thevgrate '3. This grate is arranged alongside the boiler elements 5 and is of asuitable width. It consists of a perforated plate,` and the perforations maybe cylindrical or tapered or in case inthe form of slots,.but at all events they should be small or narrowas compared with the thickness and thesuperficial area of the grate. 4l denotes a sloping face, whereby the arne is forced ina direction against the boi-lrer elements 5. The gases of combustion wfill thereby be caused vto sweep around the reiementsr giving off their essential4 part of heat to the lsaid elements and Vvthenppassing to the seal Gand iinally on to the stack 7. Preheaters or econoniizers may, if desired,be arranged inthe-seal, and in the firecham-ber superrheaters (not shown) ymay be arranged in addition 'to the steam generating elements 5. These-elements 5 are vconnected. through comparatively narrow. pipesS-with `a pipe forming a header or collector -for the boiler water,and the elements are through similar narrow pipes 10 connected with a pipe 11 forming a steam header. n

The water header` 9 is soarranged that sediments or heavier impurities contained in the waterwill collect therein. In order to avoid the .damage which mightfollow froinsuch sediments being burnt 4fast-totheboiller walls, the water header 9 is so arranged in relation to the grate 3 that it cannot be swept on its underside by the iiame.

During the combustion the gases will rise in temperature and consequently their volume will Vbe considerably increased. The result will be that the gases obtain an expansive pressure "tending to force them Aaway from the chamber above the grate, "but on account Vofthe 'over-pressure beneath the grate and the Y`specialconstructionof the latter', a forcingback willdbeexcluded and, even if no other ineasuresfare taken to produce a draught, the gases will be forced by the pressure of eX- pansion to :pass by the boiler :elements 5 and out into seal 6 and stack 7 after having given o'the'mo'stpart of theirheat to the elements 5. Theiga'se's .arrive into the stack without any considerably Yhigh temperature.

.By the lcooling the 'gases' of combustion will again :decrease in volume, andV it is therefore p ossib'leto-"inake the channels with successively'decreasing cross section vwithout increasing their velocity. This may 'preferably be obtained by arranging'the elements 5in a ring and causing the gases to pass through concentric channels,-towardthe central part of the boiler, where'I the stack is located. A reduction ofthe dimensions vof the boiler' system is thereby obtained.

`Iffor some reason a boiler element should crack, it .might be supposed that a great zaccident would happen, especially on account 'of the high steam pressure prevailing'in the boiler. Such a thing wiilnot take place however, `because in 'the narrowed connecting pipes ,10 'betweeny v'the elements 'the-steam will meet ahigh frictional resistanceand, in addition, will be subjected to losses due toshoc'ls, 1Wherebythe liv-ingforce of the :outflowing steam willfbe of no d anger.

iThe' arra-ngemeiitshown possesses 'the fad- 'vantage that the construction can? be standardized,'because' boiler elements Iof Ithe same dimensions can be used -to` bufild Eupboilers -of different capacity, the 'latter 'being simply variedby the number of elements and by arrangi'n'gthe elements in one or inorerows-or groups.

recording Jco-Figs. 1 `to 'Sthe boiler` elements are `presumed to be`locatedalong one and'zthe same plane. Figfi sho-ws'element-s arranged as acurved row, thestacl being arranged in the 4central vpart inside such -a circular row. 'Qbviously other vmodiiications can be made V without departing vfrom the spiritof the inxf'ention.

l. Ahigh pressure boiler with small IWater content, comprising an .air and'fuelniixing Y combustion chamber, a combustiongas ydistributing grate, steam generating elements in said chamber and placed along thepassage -of the combustion gases, a stack and a seal .establishing combustion chamber andY the-stack and causcommunication .between *the ing a resistance to the movement of the gases so as to obtain an equal distribution of the heat in the heating chamber, a fuel chamber below the grate, and means to supply the same with a mixture of gasiiied fuel and air under` high pressure, the said grate having perforations of small cross sectional area in relation to the total grate area and permitting controlled passage of the mixture to the combustion chamber.

2. Apparatus of the class described, comprising a structure forming a fuel chamber7 a combustion chamber above the fuel chamber, a stack in rear of the combustion chamber and walls forming a seal establishing communication between the upper end of said combustion chamber and the lower end of said stack, one of said walls forming also the rear side of said combustion chamber, said wall overhanging the lower portion of the combustion chamber and having a downwardly and rearwardly inclined diverting surface7 a grate between the fuel chamber and the bottom of the combustion chamber and also overhung by said wall and said inclined surface of said wall and a steam generator in the front portion of said combustion chamber, entirely oontained in said combustion chamber and opposite said wall.

3. In a high pressure boiler with small water content, the combination with a fire chamber containing steam generating elements positioned along-side on the wall of said chamber, of a fuel chamber, to be supplied with a mixture of gasified fuel and air, a grate separating the fuel chamber from the lire chamber, located alongside the said steam generating elements, a stack and a gas seal between stack and ire chamber and pr0- viding a resistance of the outflow of the combustion gases expanded by the combustion occurring in the fire chamber.

4. In a high pressure boiler with small water content, the combination with a fire chamber containing steam generating elements arranged alongside one wall of said chamber, of a fuel chamber7 to be supplied with a mixture of gasiied fuel and air, a grate separating the fuel chamber from the .ire chamber located alongside the said steam generating elements, the said fire chamber having a wall arranged opposite the abovenamed wall and provided with parts overhanging the grate and spaced from the generating elements for directing the stream of combustion gases in Contact with said elements, a stack7 and a gas seal arranged between stack and ire chamber and providing a resistance to the outflow of the combustion gases expanded by the combustion taking place in the lire chamber.

In testimony whereof I affix my signature HANS CHRISTIAN BJERING.

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