US2098760A - Liquid fuel burning installation - Google Patents

Description

Nov. 9, 1937. H. A. ROMP 2,098,760

LIQUID FUEL BURNING INSTALLATION Filed Feb. 8, 1955 lNVENTOR: H. A. R0,

BY H15 ATTORNEY Patented Nov. 9, 1937 I UNITED STATES PATENT OFFICE LIQUID FUEL BURNING INSTALLATION Application February 8, 1935, Serial No. 5,535 In the Netherlands February 15, 1934 3 Claims. (01. 122-1) The invention relates to liquid fuel burning insumption than corresponds to the amount, of stallations of comparatively small capacity, such steam developed. When using an open constant as in use, for example, for boilers of central level tank the steam pressure available is only heating installations. The object of the inventhat corresponding to the difference in height tion is to provide an installation which makes between the constant level tank and the burner; 5, no high demands upon the fuel to be burned seeing that in this respect one is bound in practherein and is specifically suitable for burning tice to certain limits, the steam pressure is commineral oil residue, i. e. the non-distillable or not paratively low, so that-unless special arrangereadily distillable part of mineral oil very rich in ments are made-the atomization and conse- 10 strongly carbonizing substances, such installation quently also the combustion is poor. '10 being moreover simpleand relatively inexpensive. 3. When using water from the mains the chan- For burning such heavy fuel practically only nels and reservoirs, in which the steam is dethe steam injection burner can be considered, veloped, are usually clogged very quickly owing in which, as is known, even very heavy residue to the formation of boiler scale, which soon gives can easily be burnt free of soot. This is due to rise tointerruptions in the operation or unsatis- 15 the fact that the steam has, besides the mechanifactory efliciency. cal atomizing action, also a chemical action, viz. The manner in which these three difliculties the conversion of the soot, formed as a result of have been overcome according to the present ina local shortage of air, at temperatures above vention particularly by the construction of the,

900 C., particularly at temperatures ranging besteam generating installation, is shown in'the tween 1200 and 1750 0., into carbon monoxide following description, where a hotwater boiler and hydrogen, which gases are then burnt withof a central heating installation has been chosen out smoke at a suflicient air supply. as an example. Attempt has been made to remove the draw- The drawing shows in sectional elevation my back of a steam-boiler being required for this invention applied to a hot water boiler of known kind of burners by adding to the latter special construction. Referring to this drawing.

arrangements for developing steam by the heat A is the hot water stove of a central heating of the flame. The fact that the burners of this installation of one of the types usually applied categoryto which belong also those according for the use of solid fuels. I is the grate, 2 the n to the inventionare yet being used so little in ash-pit door, 3 the fire door, 4 the flue pipe and spite of the excellent results obtained in burning 5 a plate for guiding the gases.

heavy oils, has to be mainly ascribed to the fol- The burner proper B extends into the opening lowing three drawbacks: for the fire door 3 and comprises a reservoir 6 1. The rate of outflow of the steam has a filled with a boiling liquid on top of which aoontendency to show periodical fluctuations, the so denser 1 with cooling fins 8 is placed. Once the called pulsatiomresulting, during the moments of burner is in normal operation the flame heats the weak outflow, in a poor atomization of the oil and underside of the reservoir 6 to such an extent an insufficient amount of air being sucked in, as that the liquid contained in it boils, so that the a consequence of which the combustion is intemperature of 6 is maintained constant. The

complete with a strongly sooting flame. On the heat from condensation of the vapours of the 40 other hand during the moments of strong outboiling liquid is given off by the cooling fins'to flow too much steam and air are blown into the the combustion air sucked in through the openflame, whereby the latter is frequently extining 9. In this manner this heat also promotes guished, thus causing the danger of explosions at the combustion process.

subsequent ignition. The pulsation of the out- In the reservoir 6 a coil ll, l2, for generating 4 flow of steam renders an accurate adjustment steam is mounted. The necessary water comes impossible and gives unsatisfactory combustion. from the tank C installed at a level a few metres 2. The pressure of the steam in these burners higher than the burner, passes a non-return cannot be higher than that at which the water valve Ill preventing reflux of the water to C and is fed. As is well known a direct connection to subsequently enters a spiral ll of downward coils 5 the water mains is expressly prohibited by the in which it evaporates, after which it ascends majority of the public utilities, but even when althrough a spiral l2 of upward coils. lowed the required adjustment to a constant pres- In the arrangement as described a pulsating sure, owing to the small consumption of water by outflow of the steam is further avoided by the the burner, causes a much larger water conobservation of the following points: 55

1. The temperature of the evaporation member is always constant, 1. e. equal to the boiling temperature of the liquid in 6, in contradistinction to other burners, whereby the temperature of. the evaporation member has to be maintained by the direct heating of the flame and the inevitable fluctuations in the temperature of the steam by direct heating give rise to an irregular feeding of water and an irregular outflow.

2. The volume of the steam space and the amount of water in the evaporation member are reduced to a minimum, so. that an extremely small quantity of water fed in excess already brings about an increase of pressure, whereby the non-return valve shuts off the water supply. If the steam space were larger, then in a similar case there would be a longer interval between the commencement of the increase of pressure and the closing of the valve. The later the valve is closed, the more water is fed in excess, the higher the pressure continues to rise after the closing of the valve and the longer the valve has to be kept closed as acorrective measure. This constitutes an important element in the phenomenon of pulsating.

Of course the non-return valve should be constructed so light that'it closes readily with a very small pressure difference, whilst it should further be located as close as possible to the spiral l I.

In order to prevent pulsating it is necessary that the inertia of the aggregate consisting of evaporatingelement and non-return valve is as small as possible.

However, if water from the mains Were used an installation with so small a steam space would soon become clogged-up by boiler scale; with the installation according to the invention the formation of boiler scale is therefore avoided by feeding'distilled water'to the burner, which is obtained by means of the heat from the installation itself.

On the stove A a closed reservoir E is situated filled with water through pipe 2| from the water mains. The level of water in the reservoir is kept'constant by means of a float valve 22. This water is heated by the burnt gases and the water vapour developed escapes through the line I6 extending from above the liquid level and led through the flue in order to avoid condensation.

At a little distance above. the tank C the line 16 leaves the flue and the water vapour is condensed in the air cooled sloping condenser l1. The distilled water runs 'into'C. A possible excess of water flows back to C through the overflow line I8 extending to below the water level in E.

The result of this arrangement is not only that the burner operates with distilled water but also that the heating of E can be adjusted in such a manner that C is always filled up to the overflow, so that the generator coils ll, l2, are always fed with water at a constant pressure.

combustion chamber material.

size of the flame, the passage of steam and that The formation of boiler scale now takes place in the reservoir E, which should therefore be cleaned, say, once per season.

The oil is contained in a tank D installed at a level a few metres higher than the burner and flows through the line I9 to the burner nozzle l3, where it is atomized by means of the steam from the spiral l2, mixed in the mixing cone M with the combustion air entering at 9 and burnt in the l5 lined with fireproof In order to be able to control the of oil in the burner nozzle are adjustable by means of valves 23 and 24 respectively.

Since on account of practical reasons it is impossible to place the water tank much more than 5-7 metres above the burner, it is evident that the atomization by the steam. takes place at a pressure which, in view of the resistance in the spirals H and I2, at full load certainly will not exceed 0.5 at.

What I claim is:

1. In a steam generating apparatus the combination comprising a heated liquid bath, a coil immersed in said bath, a Water receptacle connected to said coil at one end of said coil said water receptacle being "mounted at an elevation higher than said coil, a condenser discharging into said water receptacle, a water vaporizer connected to'the inlet side of said condenser, an overflow pipe from said water receptacle to said water vaporizer and a conduit leading from the other end of said coil for a connection to an oil burner. 1

2. In a steam generating apparatus the combination comprising a constant temperature liquid bath, a coil immersed in said bath, a condenser for condensing Vapors arising from said bath, a water receptacle connected to said coil at one end of said coil, said Water receptacle being mounted at an elevation higher than said coil, a condenser discharging into said water receptacle, a water vaporizer connected to the inlet side of said condenser and a conduit leading from the other end of said coil for connection to an oil burner.

water receptacle connected'to said coil at one end of said coil, said water receptacle being mounted at an elevation higher than said coil, a condenser discharging into said water receptacle, a water vaporizer connected to the inlet side of said condenser, an overflow pipe from said water receptacle to said vaporizer and a conduit leading from the other end of said coil for connection to an oil burner.

HENDRIK ARNOLD ROMP.

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