US2127172A

US2127172A - Fcknace bukner

Info

Publication number: US2127172A
Authority: US
Publication date: 1938-08-16
Anticipated expiration: 1955-08-16

Description

| HERMITTE FURNACE BURNER Aug. 16, 193s.

Fil-ed May 17, 1937 2 Sheets-Sheet l vllllllllll .Puentes Aug. 1c, 193s UNiTaD .STATT-:s

FUBNACE BURNER Y 'mais nemica, Paris, France, minor' to ,sc

clt'llateau, Paris, France,Y a corporation of France 'application may 11, 1931, sei-iai No. 143,229

lin Franc May 2 3. 193s s ciiiinrii. (ci. 15s-ssi Therev exist furnaces heated by means of a liquid fuelgsuch as mazout, in which the feed of said fuel is controlled through anoutilow or discharge conduit tted on the delivery pipe of 5 the burner feed pump.

This pump is for instance a volumetric pump working at uniform speed and supplying. consequently, a uniform total feed. TheV variation of the section of this discharge conduit, since it permits of returning a portion of the fuel to the intake of the pump or to the feed tank thereof, permits of controlling at will the portion of the v delivery that passes to the burners.

Therefore, in the case of a furnace fed by means of a 'single burner or a fixed number of 'burners all controlled byl the same discharge means, the useful feed of fuel supplied by said burner or burners depends merely upon the positlonvof said control means. Butlf the number of burners in operation is variable, according to the working conditions of the system, then the total useful feed of mazout depends both upon the degree of opening of said discharge means and upon the number of burners in service. For

a given position of the discharge means, for instance, the useful feedwill be in proportion ofv the number of burners in service.

Inversely, in order to obtain the same useful' feed with different numbers of burners, it is necw essary to give different positions to the discharge means. g

This may involve disadvantages, especially when the control n ieinr r is operated by an automatic regulator. For instance, in the case of 85 a boiler furnace, the opening of the mazout discharge may be automatically performed either by 'a steam pressure regulator or by a steam feed regulator, or again by any other combination. 'In these .various cases, the obtainment of the 4o same useful feed of fuel will depend upon whether thereds la greater or smaller number'of burners in service for differentposiiions of the control member, that is to say for different valu of the control parameter, to wit pressure or feed of Now, itis generally desirable that the determination of this variable should be always the same fora predetermined rate of combustion, whatever be the number of burners employed for obtaining this rate of combustion.. The object of the present invention is to provide a 'system with which the control of the rate of feed of fuel is independent of the number f of burners in service, this rate of feed being determined solely'by the position of the regulating member which controls the discharges; fuel.

According to the essential feature of the present invention, I provide, in connection with the delivery pipe of 'the fuel pump, a number of.` discharge circuits equal to the number of burners, each of these circuits being-tted with a. control 5 member operated in such manner that, at any time, the opening of the passage is the same for all the circuits, andwith a cut-off. member or valve adapted to be always opened or closed at the same time as the corresponding burner. i 10 Other features ofthe presentA invention will result from the following detailed description of a specific embodiment thereof.

A preferred embodiment of `the present 1n- 'vention will be hereinafter described, with` ref-l la erence to the accompanying drawings, given merely byway of example, andin which: Figs. la andl 1b are respective portions, intended to be assembled along line a`a. of a diagrammatical view illustrating thel general arrange- 20 ment of a system according to the present invention.as applied to the particular case of a .boiler furnace having four burners, .the steam pressure of the boiler being automatically lregulated; 25 Fig. 2 shows the curve of variation of the fuel pressure as a function of the useful feed to the furnace. i

The fuel. for instance-mazout, drawn from tank I by pump 2, is delivered through pipe. 3 30 into chamber'd, and then,- through pipe 5, to a plurality of burners, for instance four in the particular case. These burners are designated on the drawings by reference characters 6--87-,6'2-

Chamber ii is provided with discharge or return orifices, 1, 1', 11",,and 1"' (the number of which is equal to the number of burners) vadapted to return to tank I a portion of the mazout present in tank- I, through return conduit 8. The useful 40 section of these discharge orifices is controlled by the position of four adjustment needle valves 9, 9',-9", and 9"' having identical profiles and which move simultaneously under the action of a piston I0 with which they are connected through 45 a transverse member II, in such manner that the displacements of these needle valves are always the same for all of them. These needle valves may bereplaced by any other/equivalent means giving, for each position of the whole, an 50 equal section of the orices 1, 1', 1" and 1'.". Finally, valves or other cut olf means I2, I2',

` I2" and IZ'" are adapted to cut off each of the burners from the mazout feed pipe 5, and, on the other` hand, valves I3, i3', I3" and I3" are in- 55 I terposed between 11', 1", and 1"' and the pipe I through which mazout is returned to tank I.

- and the burners lPump 291s of the'volumetric type, driven at a uniform speed, therefore supplying a constant feed of mazoutl supposing that all the valve I2", I2" and Il, I3', Il", Il" are open, it is clear that for a certain opening of needle valves 9 to 9" the total delivery of the pump is distributed in a given proportion between the burners and the return pipe 8. 'If the needle valves are closed, the whole of the delivery of the pump passes through the burners. If, on the contrary, the needle valves are fully opened, there is substantially no feed through the burners. In other words, the useful fuel feed can be controlled by determining the position of the needle valves, that is to say the position of piston I0.

Now, it will be supposed that, without'modifying this position, some of the burners are brought out of service, for instance burners 6" and''", by closing valves I2 and I2. and also, simul taneously, valves I I" and I3".

It will be readily understood that the distribution of the total feed between the return pipe 8 the useful feed remains the same. However, `as this useful feed now passes through two burners 6 and 8', whereas, precedingly it passed through four burners, the pressure of mazout through the feed pipes and at the outlet of lthe lpump has now increased.

In a general manner, and supposing that for burners is used, an equal number of valves will be opened on the return circuits above referred to. When designating by Sn the maximum opening of each of the discharge to 1"', the total passage for the useful feed of fuel is p.Sn and the total passage for the fuel returned to the tank is p.Sn.X, in which X desigpates the degree of opening of the control valve and Sn the maximum opening of each of the discharge passage It follows that, under these conditions, the total feed of the pump is distributed betweenthe returned to the tank Sn and Sax..

If I keep the same-opening of the regulating o r control valves, that is to say the same value of X, but I make use of q burners instead of the total passages become respectively Saa and Sn.q.X. f ere ore, the distribution of the feed proportionally to numbers v This system therefore ensures the independence of the control of the maxout feed, which ldepends solely upon the position of piston III and the number of burners in service. 'I'he bringing in to, or out of, service of a burner takes place by simultaneously opening or closing one of the 'valves I2 and the corresponding valve I3 to II'", this operation having no disturbing influence upon 1 the control of the fuel feed.

As it is generally advantageous to employ, for a given rate of combustion, the minimum possible number of burners permitting the flow of the lcorresponding feed of mazout, the control of the l furnace might take place in the following manner:

All the needle valves 9 to 9"' being fully opened, valves I2 and I l are opened, the other cut off valves remaining closed, and only burner i is In order to Increase the rate of combusme'ans l2, lr...

6 is not changed, that is to say combustion, a number p oi' orinces or passages 1.

useful feed and the amount pl I ` side of deformable feed is increased by further lowering piston I 0.' the useful feed vary- The delivery pressure and according to curve A'B' of Fig. 2, and when the maximum feed 2Q, corresponding to two burners in service, and to pressure P, has been reached, the third burner is brought into service by simultaneously opening valves I2" and I3".

'I'he starting of the fourth in the same manner and, for the rate of combustion, the inverse operations are to be effected, by closing always, simultaneously, the cut off valve controllingA the burner that is tobe brought out of service and the cut-off valve inserted in the corresponding return circuit. a device automatically It is possible, with such to control the position of piston I Il and of the discharge, or return, valves by means of any regulating means.

The example hereinafter described applies to the case of a boiler furnace with adjustment of the steam pressure.

The pressure transformer I 4 is connected through a pipe I 5 with the steam header of the The steam pressure acts upon a manometric deformable box I6 simultaneously. .with a spring I1 and the pressure existing in as econd manometric deformable box I8.

'I'he displacements of the bottom of this deformable box are transmitted to a valve 49.

On the other hand, a pump 20 draws oil from -a tank 2| and delivers it under pressure into pipe 25. These two orifices 2l and- 24 are defined by the position of valve I 9, in such manner that one of theni increases when the other one dey creases and inversely,A which involves pressure 4variations in the intermediate chamber 26., 'As this chamber is in communication with the -inbox Il, it is clear that the system is in equilibrium when the oil pressure is equal to the dinerence between the steam pressure and the strength of spring I1.

Finally, I obtain, in pipe 21, an oil pressure which variesl exactly in accordance with the vari-" ations of the steam pressure. This oil pressure -acts upon piston Ill in opposition with spring 2l.-

When the amount of steam required' from the boiler increases, for instance as a consequence of the opening of the. output passages to the utilization apparatus, the pressure in the header decreases and also the oil pressure in pipe 2l also decreases. Piston III.' therefore moves downwardly, which closes the fourorifices 'I to 1"' the burners. yThis increase of the fuel feed increases the production of steam in the boiler and consequently tends to reestablish the steam corresponding to the equis Pressure to its value librium of the system.

0f course, the means for controlling the position of the burner is-enected ,y the reduction ofpushed by its spring I'I,

and increases the feed to needle valves, according to the de- 76 piston 35', which Q Thiscontrol of aismva -sired result, are not in any way limited to this particular example. For instance, always in the case of a boiler, I may make use of a steam feed regulator, either alone or in combination with a pressure regulator.

The control of the number of, burners in service may. also be obtained automatically. The following device constitutes an example of automatic control starting a new burner every time;

those in service reach their maximum and, inversely, stopping a becomes possible to ensure system with a number of burners reduced by one.

For this purpose, a Venturi nozzle in pipe 5 betweenthe discharge needle valves and the burners gives a pressure drop which is a function of the useful feed to the burners, especially forrates of feed of Q, 2Q, 3Q, corresponding respectively to the maximum output of one, two, or three burners, or to pressure drops equal to H', H", H'". This pressure drop acts through two conduits 3h, connected respectively to pipe 5 on opposite sides of pistons 3|', 3|", 32', 32", 32"'. respective strengths that they are successively overcome by respective values of the pressure ,drop equal to HUH", H'". E

These pistons control the oil distributors 33', 33", 33"', connected on the other hand to pistons 34'., 3d", 36" which control valves I2', I2", I2"

- and to pistons 35', 35",`35"' which control valves I3', i3", I".

In the embodiment illustrated by Fig. i, burner 6' is shown in service. 2|! into pipe 22 enters the distributor 33' through conduit 36' and leaves it through conduit 3 1'. It exerts its pressure through pipe S'upon piston 3ft', which compresses the opposing spring 39' and opens valve I2'.

Through pipe Q0', this oil pressure v,acts upon output,

valve i3. Burners t" ing out of service, the position of the'respective oil distributors 33" and 33"' corresponding thereto connecting pipes 31" and 31"' with the discharge pipes 62" and 42"' turns to the tank 2l.

Springs 39", 39"' on the one hand and 4I", il i on the other handare expanded, closing the corresponding valves.

The operation of this system takes place in the following manner:

Burner 5 andvalves I2 and I3 are still controlled manually for starting the furnace. When the output of this burner reaches the maximum value Q, the pressure drop in venturi 29 reaches value H' and piston 3l' is moved, together with its oil distributor, which I3' and brings the second burner E' into service.

If the fuel feed still increases, when it reaches the value 2Q, the pressure drop in venturi 29 reaches value H". Piston 3 I then moves, bringing burner 8" into service, and so on.

lnversely, if the fuel feed is decreased, when its value 'reaches 3Q, then 2Q, and finally Q, respectively, the pressure drop in venturi 29 passes. through decreasing values H'", H", H', respectively, and springs 32"', 32", 32' successively move back the corresponding pistons, which ybrings out of service burners 6"', i" and 8', successively.

the number of burners in serv- L ice is given merely by way of example and it 795 should be weu understood that the invention is burner every time it theworking of the 2s, inserted the venturi, and acting upon 3I'", in opposition with springs These springs are lmade of suchv The oil delivered by pump f crushes spring LI and opens and B!" are shown as bethrough which oil re-\ said return circuits respectively,

opens valves I2 and not in any way limited to this particular .example since, for instance, instead of the venturi I might make use of any feed meter, or again I might employ, as control parameter, a variable other than the feed of mazout.

For instance, I might make use, for this pur-.

use of the mazout pressure. Thedistributor 33' pose, of the stearnpressure. I may also 'make is then controlled by a piston which moves when f the mazout pressure exceeds value P (Fig. 2) and comes bacl'r to its position when said pressure drops below value p.

I n a general manner, while' I have, in the above description, disclosed what I deem' to be practical and elcient embodiments lof the present invention, it should be well understood that I do not wish tobe limited thereto as there might be 4changes made in the arrangement, disposition andform of the parts without departing from the principle of the present invention as comprehended within the scope of the appended claims.

What I claim is:

1..In a system including a number of liquid outlet means, and a vpump for supplying liquid under pressure to said means in parallel, a control device which comprises, in combination, an equal number of return liquid circuits inserted in parallel between the delivery of said pump and the intake thereof, variable passage control means in said return circuits respectively, means for simultaneously operating said passage control so that all of said control means always have the same position in all of said return circuits respectively, valve means for controlling said -device which comprises, in combination, an equal,

circuits inserted in parj number of liquid return allel between the delivery of said pump and the intake thereof, variable passage control'means in means for similitaneously operating said passage control means so that all of them always have the ,same position in all of said return circ'uitsr'espectively, valve means for controlling said' burners, and cut-oil' valve means` in each of said return circuits, and means interconnecting each of said last mentioned valve means withoneI of the first means with one of 4the first mentioned valve means, for causing them mentioned valve means, respectively, for causing, I them to be operated simultaneously and in the 'I same direction.

3. In a system including a number of fuel burners, a fuel tank, and a pump for supplying fuel from said tank under pressure to' said burners in parallel, a control system which comprises, in combination, a chamber mounted on the delivery of said pump, return circuits, equal to the number of'fuel burners, inserted in parallel between said chamber and said tank, a plurality of needle valves" for controlling the -ilow through said liquid circuits, respectively, means for simultaneously operating said needle valves so is aways the same for all of them, for controlling said in each of said return circuits, and means interconnecting each of said last mentioned valve a number of liquid means with one of the iirst mentioned valve means, respectively, so as to cause them to be opetxi-ated simultaneously and in the same di-` rec on.

said furnace, a fuel tank, and a pump for supplying fuel from said tank under pressure to said burners, in parallel, a control device which comprises, in combination, a chamber mounted on the delivery of said pump, a number of fuel return circuits, equ'al to the number of burners. inserted in parallel between said chamber and said tank, a plurality of needle valves for controlling the flow of fuel through said fuel re- -turn circuits, respectively, adapted to determine always the same passage .through all of said circuits, respectively, means, automatically operative in response to the working conditionsfin said boiler, for simultaneously actuating all of said needle valves, 'cut-oi! valve means for controlling 'said burners, and cut-0U valve means in each of said return circuits, each of said last mentioned valve means being associated with one -of the first mentioned valve means, respectively,

to be operated simultaneously, therewith and in the same direction.

5. In a system including a boiler, a furnace for said boiler, a number of fuel plying fuel from -said tank under pressure to said burners, in parallel, a 'control device which comprises, in combination, a chamber mounted on the delivery of said pump, a number of fuel return conduits, equal to the number of burners,

inserted in parallelbetween' said chamber and said tank, a plurality of lneedle valves for controlling the flow of fuel through said fuel return conduits, respectively, adapted to determine always the same passagethrough all of said respective circuits, an oil circulation system, means forautomatically controlling the pressure through at least a 4portion of 4said circulation system in" accordance with variations of the steam 4. In a system including a boiler, a furnace i'or' said boiler anda numberl of fuelv burners for the flow of fuel through burners forl Vsaicl furnace, a fuel tank, and a pump for suppressure in said boiler, means operative by said oil pressure for simultaneously aetuating-all-of said needle valves, cut-oil' valve means for controlling said `burners, and cut-off valve means in each lof said fuel return conduits, each of said last mentioned valve means one of the first mentioned valve means, respectively, `to be operated simultaneously therewith, and in the same direction.v

6. In a system including a boiler, a furnace for said boiler, a number of fuel burners for said furnace, a fuel tank, and a pump for supplying fuel from said .tanki under pressure to said burners, in parallel, acontrol device which comprises, in combination, a chambery mounted on the delivery of said pump, a number of fuel return conduits equal to the number of burners, inserted in parallel between said chamber and said being associated with tank, a plurality of needle valveslfor controlling,

said fuel return conduits respectively, adapted to determine always the same passage through all of said respective circuits, means for simultaneously actuating all oi' said needle valves, cut-oil valve means for controlling said burners, respectively, cut-ofi valve means in each of said return conduits, each of said last mentioned valve means being associated with one of the rst mentioned valve means, respectively, to be operated simultaneously therewith and in the samel direction, and means, operative by the working conditions, for successively opening and closingsaid burners in an automatic manner.

7. A system according to claim 6in which said last mentioned means are operative 'in response to variations of the feed of fuel from saidv pump to said burners.

8. A system Kaccordingt claim 6 in which said last mentioned means-include a Venturi element inserted between saidpump and said burners, and meansy operative by the pressure drop produced by said vVenturi element forJ controllingsaid first mentioned cut-oil valve means.

LOUIS HERMII'IE.