DE2029155A1 - - Google Patents

Description

Patent attorneys ononicr

L U I I 0 ο

Dipi.-ing. Walter Meissner Dipi.-ing. Herbert Tischer

■ IRÜN-QRUNIWALD MUNICH

• 8 Munich 2, d «n ^{June 12} , 1970

TaITi / ih

F «rn * pr.9OOeB7

Foster Wheeler without Brown Toilers Limited London / Great Britain

a fluidized fuel oil furnace

The invention relates to a fluidized fuel bed working innovation, especially for steam boilers.

±) the fluidized fuel bed of such a furnace exists from a loose layer of fuel particles, from most of which are ash and a small amount of coal dust are. The particles are driven by the otrom of the combustion air carried, which flows through the bed at sufficient speed to keep the particles suspended · As is known Such a fluidized bed of solid particles behaves like a boiling, turbulent liquid. The coal particles burn in the air and to sustain Fresh coal particles are continuously fed to the incineration and particles are continuously generated through the overflow (mainly bush particles) deducted, with the bed height is kept essentially constant. ■

009662/0280

BADÖRtälNAL

The »heat generated in the fire can be in various ways üi / ice used to generate steam // ground, i ^ ine solubility is called the ones flowing off the jet To conduct combustion gases through pipe bundles.> Evor ~ u {jt will but an arrangement in which at least the oieuerohre of the steam boiler Ie fuel bed itself ran since then very high heat transfer .. values can be achieved and a satisfactory cooling of the fuel bed is obtained, so that within the fuel bed the ociineizterr.x; erat; ur the ash is not reached.

The establishment of the / provision for the purpose of adapting to the respective required steam quantities and also the sealing of the superheating temperature isc difficult. Therefore there is a task the invention is to provide a simple means to adjust the jet height and accordingly the heat output quickly adapt to the respective boiler loads.

This object erfindungsgekäiJ Wiru at a firing! * Of the initially mentioned type by the overflow _s DAT for changing isetthöhe is adjustable in nöhe ₀

if the height is adjusted while the control is running, see above more or less Seilcaen go through the overflow until the bed height adjusts itself to the new height of the "overflow" adjusts.

Such. establishment is very simple and effective. The bed height can be changed very quickly, for example the total heat output of the fuel bed is reduced should be, the bed height will be lowered by ii of the deduction is lowered, the bed volume increases accordingly reduced. When lowering the fume cupboard, excess particles quickly go through the overflow until the bed is back. corresponds to the newly set height of the trigger and is stabilized.

009952/0280

-this -iiriot.position uer- ~ e "Ct: iohe can be in different • iO: .-: o: uo; ei, u'Zt;'/.- earth: ,, .ienn!" for example aie <~> iederohre ui: u, oJOi * ub ^ rhitseiurohre una / oaer ^ v.ischen Überhitzerrohre aeü Lii '^ i fkessels so: u: "eoranet sine, aaii sie v; eni _L stens part-. '.veiae i: a he fluidizes. izrenns toff bed, the ii.n. ^: share ae. "-ehe aea jrennsio-'ibetta also the \ trae aer the heat transfer surfaces located in the fuel bed and the relative heat transfer value of the different 5L.;.,: hot ve.'iinaert we" den. In addition, the relative noise absorption of the ear surface, which is in the ..ri.imüi.off bed, and of the onvectiona-it ear surfaces, which are heated by the hot combustion gases coming from the fuel bed, can be changed. The overheating or intermediate temperature ka :; »: also iiiit, aer ^ elast-un ^ fcere ^.

Another advantage of the overflow that can be set in aer i. Ue is that it can compensate for inaccuracies or imbalances in the overflow of the control.

g the .ι poor le ia tun *: and accordingly the nt height as well as the -u-öncje an ν bersci.uüluf t is particularly critical with low loads. A preferred application example of the invention therefore has the fluidized fuel bed with a height of:; unehiiienae cross-sectional area "- but also has a relatively small change in the height of the fuel bed with small oil heights the jettvolumens, whereas at higher oetthöhen same altitude change to a much higher magnification of 5ettvolumens leads, hot firebox, aie at a constant \ uerschnittsflache of jsetts about aie whole j3etthöhe working time, it is almost impossible that iuenge the set over excess air, without either a to blow out large, narrow, smaller ropes from the bed or not to fluidize larger particles. 3in a furnace that is preferred according to this

009882/0280

Embodiment of the invention is carried out, wherein thus the cross-sectional area of the fuel bed with the Increases in height, adjusting the proportion of excess air only causes a relatively small adjustment of the Bed height and there the air at the bottom of the fuel bed with higher speed than in the upper part of the fuel bed flows plays the problem of retaining smaller particles in the fuel bed and fluidizing larger ones Particles are no longer an essential hell.

In addition, this shape of the fuel bed has the advantage that the air speed required for fluidization is lower at the top surface of the bed than further down in the fuel bed, so the air speed at the bottom of the fuel bed is sufficiently high to fluidize the fuel particles and ensure good mixing to cause, the air velocity at the over surface of the fuel bed to be much smaller and ^ was _$ that ver ~ hältnlsmäßig small Brennstofftelichen are retained, so that only a relatively small loss arises at fuel particles and entrained particles from the fuel bed and its subsequent deposition becomes easier. This can be of particular importance when the fluidized fuel bed is operated at a pressure above atmospheric pressure, the combustion gases being supplied to a gas turbine for expansion and therefore having to be relatively free of entrained particles.

The height setting of the overflow was generally more arbitrary • “This is done, -If there is one execution, the fluidisieMe Wall enclosing the fuel bed has a vertical slot on, which is made up of a "height" which can be divided up with "an outer" socket provided upper slide is covered * iird. of? the slot Covering bags in all orders according to Öfoen or, rates

shifted, the height of the overflow and the .detthöhe set. Around the slide or the (^ baffles To keep asclie-free, the air pressure can be outside the das fluidizing fuel bed enclosing wall set higher than the pressure in the fluidized fuel bed. This can be achieved simply by adding the combustion air on the outside of the enclosing the fuel bed Walls of the furnace first down and then through the permeable air distributor at the bottom of the fuel bed upstairs, flows. '

Further details of the invention emerge from the following description in connection with the drawing. Show it:

^ ig. 1 a vertical section through a

Firing according to the invention for a steam boiler}

2 shows a vertical section through the overflow of the inflation rate after 5 ¹ Ig. 1 on a larger scale;

i'ig. 3 is a view looking at arrow 3 in FIG Fig. 2}

Fig. 4 is a section along line 4-4 in Fig. 2j

Fig. 5 is a partial view of a furnace with in the High increasing cross-sectional area of the Fuel bed

The one that works with a fluidized fuel bed Firing 1o according to * Fig. 1 contains a bed 12 from fluidize

OO08B2 / Ö2ÖO

(Particles enclosed by water-bearing walls 14 which consist, for example, of bores or tube plates provided with fins. At the 3oden of the bed 12 is located a permeable air distributor 16. The fiohrwalls 14 are surrounded at a distance by an outer jacket 18, which together with the Hohrwwall 14 has an annular air inlet duct 2o forms.

Inside the bed 12 there are two tubes 22 which flowed through by water coming from a steam-water drum 24 is supplied or /. in this flows back. These Steam-water -'- drum 24 is either inside or outside of the outer mantle 18. The one in the steam-water-Irommel 24 separated steam flows through a first superheater 25, with at least a part of the length of its pipes in the nice 12 lies. The steam continues to flow into a second lonvection superheater 26, the inside of the hot combustion gases is suspended above the jet 12. The feed water is fed to the steam drum 24 via a feed water preheater fed, which is arranged above the superheater 26 »Although a reheater is not shown, such be provided either above and / or in bed 12.

After flowing through the feed water preheater 28 flow the combustion gases in separators (not shown) to entrained (particles to be separated. If the! inflation 1o is essential If the operating pressure is above atmospheric pressure, the combustion gases are fed into an exhaust gas turbine (not shown) where they relax, -dt the exhaust gas turbine, a compressor is operated, the fresh one Combustion air delivers into the air inlet duct 2o.

The bed 12 consists primarily of ash particles and some coal particles, Irish coal particles (coal dust)

00986270280

uurcli a Jiinlaß 3o fed, while "lacks an excess of particles through an overflow 32 whose height position i;. exiiäü aer ülrfindun ;, is adjustable uieser overflow 32 will be described below in detail · üeine type iat in i'ifc L '. up to 4 shown

> -An opening in the wall 14 is provided, that one of the tubes 34 of the tube wall 14 into the bed 12 vex'set ^ t is, so that it is no longer with the other ears 34 is aligned, over the opening thus formed is a box ]> fc> set, which has a front wall 37 with an outlet slot 38 and * has a rear wall 4o. Inside the box 36 is a Slide 42 slidably arranged · This slide 42 is provided with an outlet connection 44 which protrudes through a longitudinal slot 46 in the rear wall 4o of the fastener 36 to the outside.

Visciien the front wall 37 of the box j> 6 and the tube 3 ^ is a layer 48 of heat-resistant insulating material to protect the overflow 32. In this layer 48 an outlet 5o is provided opposite the vertical outlet slot 38. Spring-loaded "apfen 52 pass through the through ^ o Hückwand and lie against the slide 42 so that dieser.an the front wall is kept in tight contact 37" a

Operating the overflow ^ 2 is very easy. By des ücliiebers 42 in box 3t> the height of the outlet connection 44 is changed upwards or downwards. I) a fluidized Bed 12 behaves like a liquid, flow '-.' particles fall through the outlet connection 44 and the surface of the bed 12 very quickly adjusts itself to the level of the outlet connection 44 once its location has been determined.

Although the fire 1o only has an overflow ;; 2 shown has been, several overflows 32 can be over the perimeter ♦ the pipe wall 14 are provided distributed.

009852/0280 BATH ORIGINAL

In order to keep the slide 42 or the sliding surfaces clean and free of ash, the pressure is advantageously outside of the bed 12 kept higher than the pressure in the bed 12, so that air penetrates through the overflow 52 into the bed 12 ' can. This is made possible by the arrangement according to FIG. 1, . in which the air is supplied to the bed 12 through the air inlet channel 2o from top to bottom, and there at Passage of the air through the porous air distributor 16 somewhat If there is a pressure drop, the pressure in the air inlet duct 2o is slightly higher than the pressure in the bed. 12.

By adjusting the bed height by means of the overflow 52 the volume of the bed 12 and accordingly the heating power can be varied. In addition, the heat transfer to the Lower tubes 22 and aie tube of the superheater 25 are precisely adjusted if by changing the 3etthöhe more or less of the pipe surface are immersed in bed 12. Furthermore, adjusting the bed height can be used to the relative heat transfer between the heat transfer surfaces in the bed and the convection heat transfer surfaces, over which the hot combustion gases flow out of the bed 12 to change. In this way there is a Hegelung with regard to the overheating and / or intermediate overheating temperature given.

Another option, 'adjusting the bed height' to use is to find inaccuracies or inconsistencies in the design; the furnace; balance.

In the furnace 6o according to FIG. 5, a bed 62 is enclosed by a wall 64 which is designed in the manner of an inverted truncated cone, at least over the bed height, so that the cross-sectional area of bed 62 increases with height cross section of bed 62 eats Jfcreis-

009852/0280 -

6AD ORMMW & gate OAP-

shaped. However, it can also be square or rectangular. In this case form the corresponding four walls 64 an inverted truncated pyramid. With a square or rectangular bed cross-section, it is also possible that only a pair of opposing walls are inclined while the other pair of walls is vertical or only a single wall can be provided inclined. It is only essential that the cross-sectional area of the bed increases in any way with the height.

At the bottom of the bed 62 there is again a porous air distributor 16 and at least one exhaust 32 corresponding to that Trigger according to FIGS. 1 to 4. The outlet connection 44 of the trigger 32 leads here into a collecting container 66. -from this container 66 the ash is removed for further use, if necessary coal particles still present in the ash are separated off and fed back to the bed 62. ·

The shape of the bed according to FIG. 5, together with the overflow 32, which is adjustable in height with its outlet connection 44, offers a number of advantages. In the case of low loads on the furnace and, accordingly, low bed heights, a finer setting of the heating power is given compared to a coarser setting in the case of higher loads. Furthermore, the proportion of excess air can be adjusted without this causing a relatively large change in the bed height. In addition, the shape of the bed 62 has the advantage that the combustion gases exit the bed at a slower rate than the combustion air flows into the bed below, the rate of which must of course be high enough to obtain good fluidization. Therefore, relatively few solid particles are removed from the fat with the combustion gases, which facilitates the separation of the solid particles.

009852/0280
BAD OWtQINAE. O

- 1ο -

Although in the above description; the expressions "water" and "liampf" are to be used if they should use other liquids and include their vapors depending on the circumstances.

Also, details of the invention may be given without other details to be used.

009852/02 SAD

Claims (7)

latent claims 1. / Lit a fluidized, fuel bed working ! ■ control, especially for steam boilers that have an overflow Door the continuous removal of particles of fluidiyi erten separates of fbetts;, thereby ■ g e denotes, that the overflow (32) can be adjusted to change the height at a height. _. ieuerunic according to ^ mspruch 1, thereby t; e xt e η η ζ eic η η et that the oieaerohre (22) and / or L-bomit ^ errohre v.3) and / or intermediate superheater pipes of the novelty assigned ^ aupfkesseis are arranged so that they. »enijjatens partially within of the fluidized racing coi'ibetrts lie. ; ".. feuerunj according to claim 1, thereby no. e η η ze i c h η e τ, α ate at least one part of a bundle; io of drilling within the fluidized fuel tank and another .bundle of x-tubes above the release ■ bed in otrcin the hot from the fuel bed on stone combustion gases lies. 4. Furnace according to one of the preceding claims, characterized in that the fluidized Fuel bed one with; the none increasing ^ u ^ rcchnittn 1 pool has. 5 «icing according to claim 4, characterized in that that the fluidized fuel bed has the shape of an inverted truncated cone 6. Inflation according to one of the preceding claims, by g e k e η η ζ e i c h η e t that ax that 009852/0280
BATH fluidized fuel bed enclosing a vertical wall ochlitz (38), aer of a height-adjustable, provided with an outlet nozzle (44) slide (42) is covered. ' 7. Furnace according to claim 6, characterized in that that the air pressure outside the fluidized fuel bed enclosing v / and higher is set as the pressure in the fluidized fuel bed, in order to hold the slide (42) aschefi ^ egg. ü. ieuerun ^ according to claim 7 »characterized in that that the fluidized fuel bed enclosing .land (14) at .spacing from an outer jacket ('Ib) is surrounded, aer together with the wall (14) a Air inlet duct (2o) for the supply of air to the .brennstoffoett Forms so that the air pressure outside the wall enclosing the fuel bed is set higher than that Pressure in the fluidized fuel bed. 009852/02 8 0 BAD ORIGWAt Blank page