US2201621A - Steam boiler and power plant regulation - Google Patents

Description

May 21, 1940.

w. D. LA MONT" 2,201,621 STEAM BOILER AND POWER PLANT REGULATION I Origihal Filed Nov. 13, 1933 2 Sheets-Sheet 1 INVENTOR y 1940- w. D. LA MONT 2,201,621

' STEAM BOILER POWER PLANT REGULATIQN Original Filed Nov. 13, 1933 2 Sheets-Sheet 2 ,bwe nl'qr Mfier Doaylasla iiloni IIIIIIIIIIIIIIIIIIIIIIIIII 4 Patented May 21, 1940 STEAM BOILER AND POWER PLANT REGULATION Walter Douglas La Mont, North Colebrook, Conn., assignor to W. D. La Mont Inc., Wilmington, Del., a corporation of Delaware Original application November 13, 1933, Serial No. 697,788. Divided and this application July 3, 1934, Serial No. 733,629

9 Claims.

This invention relates to highspeed steam and power producing apparatus and high speed methods of operating the same. i

It deals with supercharged steam boilers and high speed, light weight power plants using such a boiler, especially a boiler burning fluid fuels, in which all fluids; namely the fuel, the air (for supporting combustion), and the main working fluid in the tubes of the boiler, each flow at I extremely high velocities in the performance of their several duties. It especially concerns steam power plant and boiler regulation and is a divisional application of my pending U. S.

patent application, Serial Number 697,788, filed In November 13, 1933.

It further concerns the co-ordination at all speeds, of the velocities of all flowing fluids, to insure the maximum and constant evaporation of the main working fluid in a minimum period of time.

It makes possible controlled and positive water input into each tube of the steam generator with controlled unidirectional flow or controlled nonunidirectional flow of the main working fluid in my steam generating elements as desired under conditions of high temperature radiant heat transfer at high rates of heat release.

A main object of my invention is to reduce the size, weight and cost of high speed steam :io generators and high speed power plants. I do this by increasing their speed of operation.

By my'improved methods of operating said generators, I insure their continued perform-' ance .under long sustained, overload condition through many years of life up to the limit of the maximum heat load conditions for which they are designed, without destroying the steam generator, practically regardless of how rapidly combustion temperatures, or load conditions may 40 change, or how fast fluids in all my high speed generator fluid streams may flow with my improved method of supercharging and co-ordinating their various velocities.

It is vital that the main working fluid especially, flow at least with some control of surging,

cerned with the improvement of high speed steam boilers, and power plants embodying the same, and methods of operating said boilers and said power plant. Where my invention and/or any of its features, applies to flash boilers or mass 5 boilers and to high speed power plants using said flash boilers or mass boiling boilers, such improvements are well within the scope of my invention as herein described.

While my invention has been described here- 10 in as relating to steam generating apparatus is intended especially for the generation of steam from water, it will be understood that the terms steam and water as used in the specifications and claims are intended to include as 15 equivalents, any liquids which might be handled by the novel process and/or apparatus herein described, resulting in the generation of any vapors which might be handled by, or be useful in connection with my process and/or apparatus, and it will also be understood that many of the novel features of this invention are applicable in other fields than that for which the apparatus herein specifically illustrated and described is particularly intended.

An important object of this invention is to coordinate the quant'ity of liquid used in forced circulation in order to obtain positive input of water into each tube in suflicient quantity to protect each tube regardless of how rapid rates 30 of heat release are obtained inthe combustion chamber, up to the maximum heat eifects for which said (combustion chamber) is designed to withstand.

In order to carry out these various objects of u my invention, I arrange my boiler regulation devices so that at extremely high speeds qf/fluid flow, my steam making elements are'always protectedagainst the possibility of their melting .under high heats, said devices comprising by- 40 passes for liquid flow around valves ordinarily actuated in response either to temperature changes or liquid level changes in my steam power plant system.

Ordinarily my master combustion control 5' control and still provide each steam making element with sufllcient water to prevent that particular element from being without water and inan unprotected state against the possibility of burning out, and thereby becoming useless.

To these and other objects my invention is directed, as will be more particularly pointed out in the drawings, specifications and claims forming parts of this present patent application.

In the drawings,

Fig. 1 shows a diagrammatic layout of the power plant in accordance with the present invention with a cross-sectional view of the high speed steam boiler forming a part thereof;

Fig. 2 shows a preferred form of a pressure drop device for the tube outlets; and

Fig. 3 is a side elevation of the device shown diagrammatically as numeral 10 in Fig. 1.

The high speed steam boiler I includes waterwall coils 34, superheater coils 5|, convection steam generating coils 52, fluid heater coils 53, air preheater I2I with air passages, burner 2 and necessary pipe connections to water level cylinder 6 and to the various auxiliaries and controls. The main turbine III is shown with its exhaust lead Illa and main condenser II.

The auxiliary turbine 6 is shown driving on one shaft the boiler circulating pump 26, condensate pump I6, feed pump I 1, air supercharger 6, and oil pump 21. auxiliaries are shown with their various control valves and by passes.

The master combustion control apparatus 10 is shown with moving arm 11 and moving control rod 12 and connections to the vari s control valves.

The water level regulator 24 is shown with its control element 24A control valve I9 and interin convection gas passage H5, and my spiral cross flow air preheater with burnt gas tubes 65, and air passage I I5, also my convection generating tubes 52 in tapered gas passage I21.

All piping, valves, auxiliaries and controls are shown for proper operation of my heat transfer surfaces together with the steam generator water level cylinder 6, for maintaining a water level in the system, a suction head for the circulation pump and a source of reserve power.

The main steam turbine I0, receives steam from the steam generator I, exhausting to main condenser II. The auxiliary turbine 6, drives on its shaft the air supercharger 5, condensate pump I6, feed pump I1, circulating pump 26, and oil pump 21.

A master combustion controller 10, operates all main controls to maintain a constant boiler pressure and to supply the boiler I, with the necessary quantities of air, oil, feed water and circulating water for the proper operation of its heat transfer surfaces and to meet the various load demands.

The speed of the auxiliary turbine '6, is con- The connections of these trolled by the master controller 10, to deliver the proper quantity of air.

The oil pump 21, and boiler circulating pump 26, have by-passes with control valves, operated by the master controller 16, to deliver the proper quantity of oil and circulating water as the auxiliary turbine speed is changed to meet the requirements for combustion.

The condensate pump I6, and feed pump I1, have a by-pass ISA, with control valve I9, operated by a water level regulator 24, on the water level cylinder 8, to maintain a water level in the system.

The boiler circulating pump 26, has a cross connection 13, to the feed inlet with control valve 16, operated by the master controller 16, to augment the supply of water for the fluid heater as the heat load increases.

The opening and closing of cross connection control valve 16, is modified by the opening and closing of the feed water level regulator by-pass valve I9, so that when one valve is closing the other valve is closing. This eliminates the use of unnecessary quantities of heated water or re-circulation in the fluid heater as changes in load-occur.

The control valve 16, on cross connection 13, has a by-pass 14, with thermostat operated control valve 15. Thermostat control valve 15, is operated by a thermostat device 11, on the outlet end of a fluid heater tube 53. Whenever said tube 53, or the steam therein goes above the saturated temperature of the steam in the boiler thermostat element 11, opens valve 15, in bypass 14, to protect the fluid heater tubes 53.

The general operation of the power unit is as follows:

Starting with a water level in the water level cylinder 8, water is sent by the circulating pump 26, to the waterwall tubes 34, and convection generating tubes 52, of the boiler I. Water and steam discharges from waterwall tubes 34, and convection generating tubes 52, into the water level cylinder 6, where the steam and water are separated, steam going to the superheater tubes 5|, and excess water going to the water level cylinder 6, where it is picked up by the circulating pump 26, with make up feed and re-circulated in the system.

The steam in the superheater tubes 5|, becomes highly superheated and passes to the main turbine III, to main condenser, II; also to auxiliary turbine 6, and then to main condenser II.

Condensate from main condenser II, goes to feed water tank I5.

Starting with the feed water in feed water tank I5, this water is picked up by condensate pump I6, and sent to feed pump I1. The feed pump I1, by means of the by-pass ISA, and control valve I9, supplies water to the fluid heater tubes 53, this supply being in accordance with the demands of the water level regulator 24, maintaining a water level in water level cylinder 8.

The circulating pump 26, by means of the bypass 14, and thermostat valve 15, actuated by the thermostat 11, on fluid heater tube 53, and by means of the cross connection 13, and control valve 16, actuated by the master combustion control 10; supply water for re-circulation in the fluid heater tubes 53, when necessary for protection and proper operation of the fluid heater tubes, independent of the water level at different load demands.

The feed water and re-circulation water in the fluid heater tube 53, togetherwith any steam,

formed, is discharged into the water level cylinder 8, where the water and steam, if any, is

separated. The steam going to the superheater tube 5|, and the water going to the water level in water level cylinder 8, to be used for main taining a water level, for re-circulation and for formation of more steam.

The more detailed method of operation of my power unit is as follows:

Starting To start the boiler I, after a shut down of the boiler and power unit, it is necessary after filling the system with water to a low water level in water level cylinder 8, to insure a supply of oil.

opened valve SID, to the burner, valve BIE being closed. Onlya small quantity of oil is used and when ignited through burner door 2 I2, there is sumcient air from the opening I05, through door 2I2, and from the air passages to carry on slow combustion until steam forms and the resulting pressure causes flow of steam under pressure from the superheater tubes 5|, through the main steam line 9, through auxiliary steam line 1, past opened control valve 42, and into auxiliary turbine 6, driving auxiliary turbine 6, as it exhausts through exhaust lead 28, to exhaust lead IA, of the main turbine to main condenser II, to condensate line I 4, to feed tank I5. Valve 9IE, is then opened and valve BID, is closed, combustion then being carried on by the auxiliaries on the shaft of turbine 6.

When electrical power is available or when a motor-generator-storage battery system is used for starting, a motor on auxiliary turbine 8, drives the auxiliaries supplying all the air, oil and water for quick starting and operation of the power unit.

However, it is within the scope of this invention to use any known method of starting the steam generator.

From the time that auxiliary turbine 6, starts driving all the auxiliaries, the operation is as follows:

Feed water Feed water, whenever it is necessary before and during the'operation of the power unit, is put into feed tank I5, from the reserve feed tanks through filling line 46', past filling line valve 43, to maintain a supply of feed water in this tank for operation of the water in the system. Vent 41, in feed tank I5, is open to the atmosphere.

Feed water is picked up by condensatepump I5 through condensate suction line 29, from feed tank I5, and delivered to the suction of the feed pump Il, through connecting passage in the casings of the two pumps,'as long as the two pumps are being driven by auxiliary turbine 9, and there is water in feed tank I5.

Feed water is received from condensate pump I9, by feed pump I1, and discharged through feed pump discharge line I8, past feed stop and check valve 20, past feed water hollow cone distributor 69A, past fluid heater tube disc 92B, and

' into the fluid heater tubes 53; and/or the feed water from pump H in discharge line I8, is bypassed through by-pass line I9A, past water level regulator control valve I9, back to condensate pump suction line 29.

Water level regulator valve I9 is operated by water level regulator element 24A, through pipe pending on the height of the water in the water a level cylinder 8. The water level regulator bypass valve I9, closing or decreasing its opening with a fall in the water level and opening or in,- creasing the degree of its opening with rise in the water level.

This opening and closing of the water level regulator valve I9, opens or closes in varying degrees the by-pass line I9A, from the feed pump discharge line I8, to the condensate pump suction line 29, thereby decreasing or increasing the amount of make up feed water delivered into the fluid heater tubes 53, in accordance with the demands for maintaining a water level in the water level cylinder 8, independent of the speed ,of auxiliary turbine 6, driving condensate pump I6, and feed pump I1, and also independent of the requirements of the fluid heater tubes 53, for their proper protection and operation against the heat loads imposed on them. In general, the feed input into the fluid heater tubes from the action of the water level regulator valve I 9, will be normally increased with increase in heat load, requiring more make up feed and thereby causing a fall in water level, but often the water level may be rising or may be at too high a level or the water level may be raised by steam bubble formation at a time of sudden increase in' heat load and the water level regulator I9, may fail to close on the by-pass line I 9A, or may remain open or may not move for some time from its partially opened position at the time of sudden change in heat load thereby not increasing the input of feed water into the fluid heater tubes with increase of heat load. The action of the water level regulator valve I9, is always entirely dependent on the action of the water level.

Water forced into the fluid heater tubes 53,

by the feed pump I1, and the action of the water level regulator valve I 9, on by-pass line I 9A,

passes through the fluid heater tubes 53, in the convection burnt gas heat transfer zone, passage H5, and discharges with steam, if any is formed, into water level cylinder 3, at the top, above the water level.

The feed input, as it discharges 'from feed pump discharge line I8, just before it enters the fluid heater tubes 53, enters and passes through the apex of the 'hollow feed cone distributor 63A, which smoothly spreads and directs the flow into the holes in the hollow cone leading to eachtube. This action gives a minimum disruption of the flow of water to each tube and results in a more direct drive of the water into each tube. After the feed input passes the hollow cone distributor it enters a pressure drop device or Venturi shaped orifice 35A, in each tube in the design used for Fig. l, which gives it a pressure drop delivery into the tube, which 15.

ordinated with the pressure drop device 353, at the outlet of each fluid heater tube 53, and the quantity of water put into each tube, gives full control of the degree of compactness of the steam and water column in each tube for each heat load imposed on the tubes. I The water with steam, if any is formed, in the fluid heater tubes 53, passes through a Venturi shaped pressure drop device 353, at the outlet end before discharging into the water level cylinder 8. This pressure drop device 35B, is used to co-ordinate with the inlet pressure drop device 35A, of the design shown in Fig. 1, and the quantity of water circulated to give full control of the compactness of the steam and water column in each tube and to insure unidirectional or controlled flow of steam and water in each tube.

After the discharging water and/or steam from each fluid heater tube has a preliminary breaking up of its steam bubbles and separation of the steam and water from the Venturi shaped pressure drop device 353, then a further augumentation of the separation action by adding centrifugal force from both the twisted metal strips 66, at the outlet of each tube, and the still further separation and collection of the steam and water with the baffles 61, having openings for steam in them, the water separated from the steam discharges to the water level for maintaining a water level, for re-circulation in the system and for replacing steam generated, and the steam I passes through the main separator 69, to the superheater tube The steam generator circulating pump 26, picks up water from the water level cylinder 8, and sends it to the waterwall tube 34, the convection generator tubes 52, and/or to the fluid heater tubes 53.

The circulating pump 26, is driven by auxiliary turbine 6, which also drives the air supercharger 5, the condensate pump IS, the feed pump I1, and the oil pump 21, the speed of the auxiliary turbine 6, being controlled by the master combustion control 10, to deliver the required amount of air for combustion, although the speed of the auxiliary turbine might be used to control the amount of oil, feed water, and/or circulating water used, and it is intended to be within the scope of this invention to use any of these control means.

The circulating pump 26, picks up the water from the water level cylinder 3, through suction lead 3|, discharging it through discharge lead 32, past waterwall cone hollow distributor 63, and past convection generator cone hollow distributor 633, which acts on the circulating water in the same way as described for the feed hollow cone distributor 63A, past waterwall tube holding disc 62, and past convection generator holding disc 62C, and into each tube, past a Venturi shaped pressure drop device 35A, at the inlet into each waterwall tube 34, and convection generator tube 52.

The pressure drop device 36A, is used in each waterwall tube 34, and in each convection steam generating tube 52, in the same manner and for the same purpose as the pressure drop device 35A, described in this invention for the fluid heater tubes.

Water and/or steam discharges from the waterwall tubes 34, and convection steam generating tubes 52, at the outlet end, past a Venturi shaped pressure drop device 353, past a twisted metal separator strip 66, and into the water level cylinder 8. ,Said pressure drop devices 3513 and twisted metal separator strips 66, for each individual tube acting in the same manner on the water and steam coming from the waterwall tubes 34, and convection steam generating tube 52. as described in this invention for the fluid heatertubes 33.

As the water andsteam from the waterwall tubes 34, and the convection generating tubes 32, enters the water level cylinder 3, the cone shaped water spray with steam in the center, strikes baflie walls 63, and 63A similar to the baille walls 61, described, for the fluid heater tubes. The resulting separated steam goes through the main separator 69, to the superheater 5|, while the water falls to the water level where it is picked up again for re-circulation, by the circulating pump 26, with the makeup feed water from the fluid heater tubes 5|, where it is sent again as previously described, to the waterwall tubes 34, convection steam generating tubes 52 and/or the fluid heater tubes 53.

The discharge lead 32, of the circulating pump 26, has by-pass line 44, with control valve 44, connecting it to the circulating pump suction line 3|.

The control valve 45, is operated by the moving rod 12, of the moving arm 1|, of the master combustion control 13, which in turn is operated by change in boiler pressure in the following manner.

In Figure 3, the pressure responsive element consists of a double diaphragm construction counterbalanced by weights. The pressure to be controlled acts on the lower diaphragm, and the pressure of a sealed air chamber on the other. The upper diaphragm being made of phosphor bronze assumes a dished shape under the air chamber pressure and bears against the upper diaphragm plate. An increase of the controlled pressure moves the diaphragm plate "I upwards, but in increasing force opposes this movement as the upper diaphragm is flattened against 'the thrust plate and a larger percentage of its area becomes efl'ective to exert a downward force. This causes the diaphragm mechanism to move incrementally with pressure changes. An increase of the controlled pressure moves the connecting rod 302 upwards and acts through the lever 333 to move the pilot valve downward and admit motive fluid to the bottom of the operating cylinder. The crosshead moves upward carrying with it the compensater 331 which allows the roller 306 to move to the right. This roller is carried on the bellcrank 335 which is pivoted at 333 and supports the lever 333 at the pivot point 334. When the roller 333 moves to the left, the pivot 334 moves upward and ralsw the pilot valve to its closed position which stops the regulator after 'a movement dependent upon the extent of presduced to as low as 8 or 10 pounds, being adjusted cylinder, upon the side of which, valve 611-! is mounted, has a piston moving back and forth in its interior. This piston is actuated by oil under pressure, this pressure being created by pump 21 and acting through pipe-line 6IG and valve 6IH, returning (after it has moved the piston in the master regulator cylinder) to oil tank 38, through pipe-line 6IF. The movement of the piston (not shown) in the large master regulator cylinder is transmitted through a piston rod to the moving arm or cross member II carrying master-combustion control rod I2.

Increase in load causes a drop in boiler pressure due to a demand for more steam. A drop in boiler pressure on the lower diaphragm in Figure 3 causes the weight to fall down, pulling down arm 302. This raises the rod connected to 303, which in turn causes the opening of the bottom port in 6IH sending oil under pressure to the bottom of the cylinder. This raises element II and the combustion control rod I2.

When I2 is raised, valve 42, which is constructed similarly to valve I6, opens, thereby speeding up auxiliary turbine 6 which operates to send more air to the combustion chamber. Valve 45 inthe by-pass line of the circulating pump, as well as valve 6IB in the by-pass line of the fuel pump, are formed with reversed seats so that an upward movement of member I2 effectuates a closing of these valves rather than an opening thereof as in the case of valves 42 and I6. Thus when valve 45 closes, it cuts ofi the by-pass circuit around the circulating pump and serves to send more circulating water to the economizer and steam generating tubes. Also, valve I6 opens, sending more water to the economizer. Valve 6IB operates similarly to valve 45 and by cutting off the by-pass circuit functions to send more oil to the burner.

The reverse sequence of operations and control of the valves takes place with a decrease in load, and with an increase in pressure in steam conduit 9.

Since the master combustion control rod 12, moves with change in heat load demand, its movement can be used to operate the by-pass line 44, of the circulating pump 26, opening said valve 45, when load demands decrease, and closing said valve 45, when load demands increase,

thereby varying the quantity of water available for circulation in the waterwall tubes 34, and/or the fluid heater tubes 53, to any amount desired for any given heat load and setting of the valve.

The discharge lead 32, of the circulating pump 26, has a cross connected line I3, connecting to thedischarge lead I8, of the feed pump ll, be-

tween the feed stop and check valve 20, of line I8, and the fluid heater tubes 53.

This cross connecting line I3, has a control valve 16, and a check valve 29, also a by-pass line I4, around valve I6, with a thermostatic operated valve 15. When the valve or valves of the cross connecting line I3, are open, the circulating pump 26, delivers water positively into each fluid heater tube 53, for circulation and re-circulation in any quantity desired," at any time, independent of the water level in water level cylinder fl.

Thermostatic valve I5, in by-pass line I4, is opened or closed by the action of a thermostat device 11, on fluid heater tubes 53. When the tubes of the fluid heater have insuflicient water said thermostatic device becomes heated, as the steam formed within the tubes becomes superheated, causing the thermostat element 11, to

heat load settings, that if v column in the coiled tubes open control valve I5, on by-pass line I4, on cross connecting line I3, opening cross connecting line I3, and thereby discharging ci culating water from circulating pump 26, into the fluid heater tubes 53.

Thermostat element 11-, is set to cause the opening of valve I5, at any time the temperature in the fluid heater tubes goes above that of the temperature of saturated steam, at the designed working pressure of the boiler.

The action of the thermostat element 11, and valve 15, is independent of the water level and also independent of the heat load except indirectly, when lack of water with the heat load might cause rise in temperature in the fluid heater above that at the temperature of the saturated steam.

Control valve I6, is operated by the master combustion control arm I I, moving rod 12, with change in heat load. This rod I2, is connected to the lever valve 16, from a lever point over on the water level regulator valve stem of water level regulator valve I9. The connecting arm between rod I2, valve I6, and the lever point on valve stem I9, together with the location of both valves I 9, and I6, are so arranged at the different the water level regulator valve stem is in the open position, the rod I2, will have opened valve I6, but if the water level valve closes it will close valve I6, or close it to any degree desired, as made with the valve and arm setting.

When valve I6, is open, is open, thereby discharging circulating water from circulating pump 26, into the fluid heater in any quantity desired.

The cross connection I3, with its valves and controls is mainly for the purpose of supplying water to the fluid heater in any desired quantity for coordination with the pressure drop devices in the tubes to protect saidtubes and insure their proper operation, at any time, only when and if, the supply of feed water coming into the fluid heater is insufiicient to accomplish this purpose due to the water level condition and action of the water level regulation valve on the feed line. I

Steam The saturated steam from the waterwall tubes 34, convection generating tubes 52, and/or the fluid heater tubes 53, passing through the main separator 69, and into the superheater tubes inlet ends 5|, at the top of the water level cylinder'8, as previously described; becomes highly superheated as it passes through the superheater At the outlet of each superheater tube 5|, I place a Venturi shaped pressure 'drop device 353, adjusted to insure proper distribution of steam flow in each tube and compactness of the steam In order to maintain a fairly constant final steam temperature with variable heat loads superheater tubes 5|, are equipped, as previously described in co-pending application 6,938,714 of October 16, 1933, with a thermostat control on superheater tube 5I, with regulator, which raises or lowers the superheater coil with change in final steam temperatures, so that the position of the superheater coils 5|, relative to the waterwall coils 34, is changed from in the rear of the waterwall tubes 34, but with full radiant heat, acting on the superheater coils 5I, to a position of the superheater coils 5|, directly behind the waterwall coils 34, with practically no radiant cross connection I3,

being mainly by convection action.

As a result during the operation of my power unit at various loads the superheater coils 5|, are being automatically raised and lowered to meet the heat conditions of various loads and maintain a fairly uniform final temperature.

The highly superheated steam discharges from the outlet ends of the superheated tubes 5|, past the superheater tube holding disc 52A, into main steam line 9, where a second safety valve is generally located, (not shown).

The superheated steam in main steam line 9, passes through main throttle stop valve 6|, to main steam turbine I 0, exhausting through exhaust lead IOA, to main condenser II, where it is cooled and condensed back to water by cooling water entering inlet I2, and leaving by exit l3, in main condenser II.

The superheated steam from main steam line 9, also passes through auxiliary steam line I, past auxiliary control valve 42, to auxiliary turbine 5, which drives all of the main auxiliaries. The exhaust steam from auxiliary turbine 6, passes through auxiliary turbine exhaust line 28, to main exhaust line IDA, to main condenser I I, where it is condensed with the exhaust steam from main turbine Ill. The condensate then passes through line I4, to feedtank I5, where it mixes with any feed water from the reserve feed tanks, put into the feed tank I5, through filling line 46, past valve 43. The resulting water mixture then passes through condensate suction line 29, of condensate pump I6, to pass through the system as previously described.

Fuel

The feed oil tank 38, is filled when necessary from the reserve fuel tanks through filling line 48, past stop valve 49. Vent 50, connects the fuel oil tank 38, with the atmosphere.

The fuel oil pump 21, picks up fuel oil from fuel oil tank 38, through fuel oil pump suction line 39, discharging it to the burner 2, through discharge line 40.

Fuel oil under pressure from the fuel oil pump 21, issues from the burner, in a finely divided or atomized spray, where it mixes with the air, and after ignition keeps continually forming the gases of combustion in combustion chamber I05, at a rate of heat release proportional to the amount of air and oil mixture made available in the combustion chamber by input from the fuel oil pump 21, with its controls and the air supercharger 5, with its controls.

The fuel oil pump discharge line 40, has a lead SIG, going to the control valve 6|H, on the master combustion control 10, for power operation of its moving arm 1|, and motion of its valve operating rod 12.

Oil passing through control valve 6| H, on master combustion control 10, discharges through line GIF, to the suction line 38, of oi pump 21.

The fuel oil burner has a centrifugal atomizing chamber with by-pass opening at its rear through which 011 from the fuel oil pump, not issuing from the burner opening into the combustion chamber is by-passed back to the suction of the fuel oil pump suction line 39.

The fuel oil by-pass line 5| A, has a lever control valve 5| B, which controls the quantity of oil sent to the burner.

A lead pipe SIC is provided for using starting oil under hand pressure when starting combustion in the boiler fitted with a stop valve SID therein. when oil is supplied from this source, a stop valve GIE is provided to shut on the oil D p pp y.

The master combustion control, II, through its moving arm II, and moving rod 12, operates the fuel oil by-pass lever valve 5IB, so that if the boiler pressure is lowered from load demand the rod I2 moves, closing the by-pass valve IB, and increasing the oil output of the burner. If the boiler pressure is raised from decrease in load demand, the master combustion control rod I2 is moved so that the by-pass valve 5IB is opened, decreasing the pressure in the centrifugal chamber of the burner and the input of oil into the combustion chamber. In this manner a sufficient quantity of oil is automatically forced in the combustion chamber in proportion to the load demands maintaining a fairly constant boiler pressure throughout the system. at all load conditions.

Air

The air supercharger 5, driven by auxiliary turbine 5, picks up air from the atmosphere through its suction inlet 4|, and by high speed rotation with centrifugal action compresses and drives the air throughout the boiler air and gas passage system with the combustion gases against any pressure drop conditions occurring in the system.

The air leaves the air supercharger 5, through the supercharger air discharge line 9. which enters the circular air entrance dome passage I28, tangentially, giving the entering air a whirling motion in said passage.

Air from the circular air entrance dome passage still whirling, enters through and into the stream lined air passages |2|, of the tapered spiral cross flow air preheater. The air, as it is forced at high velocity into said air preheater air passage |2|, past the spiral tapered air preheater burnt gas tubes 55, meets with more resistance to cross flow than to spiral flow along the tapered spiral coiled air preheater burnt gas tubes 55, which result in a combination of spiral flow and cross flow of the air in its air passages |2|, giving spiral cross flow of the air along the heat transfer surfaces. The spiral tubes 55, of the air preheater are wound around the circular tapered fluid heater outer casing 225, so that the air continues to have the same whirling motion in the air preheater air passages as it had when leaving the circular entrance dome chamber.

Air leaving the tapered spiral cross flow air preheater air passages I2I, still whirling in the original direction, enters the circular air inlet passage I25, and then the circular air inlet burner chamber I22, to the burner guide vanes at the burner entrance I23.

The burner guide vanes augment the whirling of the air, leaving the circular air inlet chamber I22, without change of direction of the whirl, guiding the air into the burner throat passage I24, and on into the combustion chamber I", where it mixes with the atomized fuel oil from the burner to form the combustion gases. The ports I05 in the burner entrance wall are used for purposes of inspection and ignition when starting combustion.

Combustion gases The combustion gases formed in the combustion chamber I", from the mixed and ignited oil and air, are driven at high velocity throughout the burnt gas passagesof the steam generator I, by the oncoming air from the air supercharger 5.

The main part of the combustion gases in the combustion chamber I06, striking the bulbous central position of the combustion chamber outlet end wall 223, are dispersed toward the depressed throat I24, and this air with the combustion gases,

continues to whirl as it enters the convection generating spiral tapered burnt gas passage I21.

Since the spiralled convection generating coils 53, in the spiral tapered convection generating passage I21, are coiled in the opposite, direction to the waterwall coiled tubes 34, and superheater coiled tubes 5|, in the combustion chamber I06, the combustion gases continue to whirl in the same direction they had when leaving the combustion chamber, as they travel through the convection generating passage I21, the circular outlet convection generating passage I26, and into the spiral tapered fluid heater passage II5.

Since the fluid heater tubes 53 are coiled in the opposite direction to the convection steam generating tubes 52, the gases continue to whirl in the same direction while passing through the fluid heater tapered spiral cross flow passage I I5, as they whirled when passing through the convection steam generating gaspassage I21.

The combustion gases travelling through the spiral tapered fluid heater passage H5, at high velocity, strike the coiled fluid heater tubes 53, meeting with more resistance to cross flow than spiral flow and resulting in a combination of spiral flow along the fluid heater tubes 53, and cross flow across them, giving spiral cross flow of the gases on the heat transfer surfaces.

The combustion gases leaving the.spiral cross flow tapered fluid heater passage I I5, are guided by the streamlined entrance into the spiral tapered air preheater burnt gas tubes 65, travelling in counterflow to the air on the other side of said tubes 65, in the air preheater air'passages I2I, to

the stack gas passages I I1.

The gases leaving the stack gas passage II1, enter the streamlined entrance II8, into stack and leave the Venturi shaped stack exit to the atmosphere,

I claim:

1. In a steam power plant, a boiler of the forced recirculation type having steam generating tubes with working fluid regulating orifices in said tubes, a burner in said boiler, a turbine receiving steam from said boiler, a fuel pump, an air pump, a feed water pump, and a circulating water pump driven by said turbine, said fuel pump connected to said burner and the other pumps connected to said boiler, a steam throttle controlling steamflow through said turbine, a steam and water separating chamber connected to said boiler and circulating water pump for supplying the separated water to said circulating pump, by-pass conduits bridged across the inputs and outputs of said fuel pump, feed water pump and circulating water pump, valves in each of said by-pass conduits,'and a combustion control device arranged to control all of said valves.

2. In a steam power, plant, a boiler of the forced recirculation type including steam generating tubes and feed water preheater tubes therein, a burner in said boiler, a turbine oper-' ated by the steam delivered from said boiler, a fuel pump, a feed water pump, and a circulating water pump driven by said turbine, said fuel pump connected to said burner, said feed water pump connected to said preheater tubes to pump feed water into said preheater tubes, a steam and water separator connected to said boiler and circulating pump for supplying the separated water to said circulatingpump, conduits bridged across the output and input of each of said pumps, valves in said bridging conduits, and a combustion control device arranged to control said valves.

3. In a steam power plant, aboiler of the a forced recirculation type including steam generating tubes and feed water preheater tubes therein, regulating pressure-drop devices in at least the steam generating tubes controlling fluid flow therethrough, a burner in said boiler, a steam turbine operated by the steam delivered from said boiler, a fuel pump, an air pump, a feed water pump, and a circulating water pump driven by said turbine, said fuel pump connected to said bumer, said air pump connected to said boiler adapted to supply air to the burner of the boiler in conjunction with the fuel delivered thereto by said fuel pump, and said feed water pump connected to said feed water preheater tubes adapted to pump feed water into said preheater tubes, a steam and water separator connected to said boiler and circulating pump for supplying the separated water to said circulating pump, by-pass conduits associated with said fuel pump, feed water pump and circulating water pump, and a combustion control device responsive to the output of the boiler and the heat demands made thereupon for controlling the flow of media supplied by said pumps.

4. In a steam power'plant, a-boiler of the forced recirculation type including steam generating tubes and feed water preheater tubes therein, a burner in said boiler, a steam turbine operated by the steam delivered from said boiler, a fuel pump, an air pump, a feed water pump and a circulating water pump driven by said turbine, said fuel pump connected to said burner,

said air pump connected to said boiler adapted to supply air to the burner of the boiler in conjunction with the fuel delivered thereto by said fuel pump, and said feed water pump connected to said feed water preheater tubes adapted to pump feed water into said preheater tubes, a

steam and water separator connected to said boiler and circulating pump for supplying the separated water to' said circulating pump, bypass conduits associated with said fuel pump, feed water pump and circulating Water pump, a combustion control device responsive to the output of the boiler and the heat demands made thereupon for controlling the flow of the media supplied by said pumps, and means for modifying the control exercised by said combustion control device.

5. The combination set forth in claim 2 wherein an air pump for supplying air to the burner of the boiler is also driven by said turbine.

6. The combination set forth in claim 2 wherein is provided additional control means for said valves.

'7. The combination set forth in claim.2 wherein is provided additional devices,responsive to the conditions of the fluids in the steam generator for controlling at least one of said valves in said bridging conduits.-

8. In a steam power plant, a boiler of the forced recirculation type including steam generating tubes and feed water preheater tubes therein, regulating pressure-drop devices in at least the steam generating tubes controlling fluid flow therethrough, a burner in said boiler. a steam turbine operated by the steam delivered ,from said boiler, a fuel pump, an air pump, a

feed water pump and a circulating water pump driven by said turbine, said fuel pump connected to said burner, said air pump connected to said boiler adapted to supply air to the burner of the boiler in conjunction with the fuel delivered thereto by said fuel pump and said feed water pump connected to said feed water preheater tubes adapted to pump feed water into said preheater tubes, a steam and water separator connected to saidboiler and circulating pump for supplying the separated water to said circulating pump, conduits bridged across the inputs and outputs of said fuel pump, feed water pump and circulating water pump, valves in said bridging conduits, and a combustion control device arranged to control said valves in response to the output of-the boiler and the heat demands made thereupon by controlling the flow of the media supplied by said pumps.

9. In a steam power plant, a boiler of the forced recirculation type including steam generating tubes and feed water preheater tubes therein, a burner in said boiler, a steam turbine operated by the steam delivered from said boiler, a fuel pump, an air pump, a feed water pump and a circulating water pump driven by said turbine, said fuel pump connected to said burner, said air pump connected to said boiler adapted to supply air to the burner of the boiler in conjunction with the fuel delivered thereto by said fuel pump and said feed water pump connected to said feed water preheater tubes adapted to pump feed water into said preheater tubes, a steam and water separator connected to said boiler and circulating pump for supplying the separated water to said circulating pump, conduits bridged across the outputs of said fuel pump, feed water pump and circulating water pump, valves in said bridging conduits, a combustion control device arranged to control said valves in response to the output of the boiler and the heat demands made thereupon by controlling the ilow of the media supplied by said pumps, and means for modifying the control exercised by said combustion control device.

WALTER DOUGLAS LA MONT.

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