US1666426A - Steam plant - Google Patents

Description

April 17,1928. Y l.666,426

J R UTHS I STEAM PLANT Filed. Dec. 27, 1924 2 Sheets-Sheet l lnvenior BE aw 4Z4 fi/Aflorney April 17, 1928.

J. RUTHS STEAM PLANT 2 Sheets Sheet 2 Fild'Dec.

F m m 1| w re.

invgnior Aflorfi ey Patented Apr. 17,

J OHANNES RUTHS, OF DJIIRSHOLM, SWEDEN.-

' STEAM PLANT.

Application filed December 27, 1924, Serial No. 758,488, and in Germany and SwedenJ'anuary 14, 1924.

My invention relates to steam plants and more particularly to steam .plants wherein there is a variable steam consumption.

My invention involves a novel manner'of generating steam of high pressure, for ex ample from 1500 to 3000 pounds per square inch, or higher, and to enerate steam substantially in proportion to the demand, and atany desired temperature, but independentlypf heat supplied to the plant in the form of fuel so that the generation of heat is independent of steam consumption. For example, by this'means; a constant firing of boilers maybe obtained while at the same time the steam generation and steam consumption vary considerably.

Another-purpose of my invention is to produce a novel-means ,for superheating steam, and to' provide 'a highly efficient system wherein high pressure steam is used and superheated for different purposes.

I havediscovered that it is possible to build a practical high pressure boiler operating at pressures higher than those yet acquired in practice by means of an indirect system of generating the high pressure steam with the helpo'f a medium of high boilingpoint and having high temperature at low pressure, the said medium consisting of phenanthrene, or a similar liquid. I utiliz e such liquids also to store heat as set out herein.

I-utilize theseliquids also to superheat steam and more particularly as shown herein to superheat steam between stages of a tur bine.

With these and other objects my invention consists in the matter herein described and more particularly pointed out in the appended claims, reference being had to the accompanying drawings which illustrate some forms of my invention.

In the drawings, Fig. 1 shows a steam plant illustrating several phases of my invention part of which is taken substantially on line 1 1, Fig. 2.

Fig. 2 is a section through a turbine taken on the line 2 2. Fig. 1, showing details of the preferred manner of superheating steam between stages.

Fig. 3 shows diagrammatically a modified form of accumulatorfor. carrying out. the present invention.

partition walls 15.

Fig.' 4: is a diagram showing correspond-- mg boiling points and pressure of various liquids illustrating advantages of the present combination.

In Fig. 1, 5 indicates a boiler of any'suitable construction which may utilize any desired means of heating.

Forthe purpose of illustration have rotary air p'reheater 10 of'knownconstruction, and c0mpris i ng' a rotor 11 filled with regenerativematerial 12, which rotor rotates partly in a passage 13 for fresh air to be heated, and partly in a passage 14 for-the hot products bfcombustion, said products of combustion glvlng off heat to the rotor, the two passages 13 and 14 being separated by In this boiler 5 the above-mentioned liquid 'of high boiling point, in referring to which,

for convenience I will herein-after use the name of .the preferredliquid, phenanthrene, is vvaporized in a manner similar to that which steam is generated from water, and the vapor'generated is conducted through conduits 16, 17, 18-.and 19 into the liquid space of the accumulator 20. Check valve 121 is provided to prevent return of liquid from the accumulator into the primary boiler piping. Phenanthrene boils under atmospheric pressure at 640 F. Wherefore it is seen that a very high temperature in the liquid and vapor in boiler 5 and accumulator- 20' is obtained.

' The accumulator 20 consists of a large receptacle'having a liquid space 21 and a vapor space 22 and is well insulated as indicated at 23.

5 This accumulator is designed with respect to the heat consumption of the plant and it is built of such size that it can store sufficient heat, and give off suflicientheat, so that the supply of heat, as for example the fuel supply to boiler 5,,can be made independent of the steam consumption.

In the vapor space of the accumulator is arranged one or more elements 24 which constitutethe high pressure steam generator of the plant. I have found that av greatly improved heat transfer is effected with the high pressure elements placed in the vapor f space than if they are. submerged in the tially the pressure at which steam is to be generated. The relatively cold water entering the elements 24 absorbs heat through the walls of theelements and condenses the phenanthren'e vapor in the vapor drum 26, the condensate returning to the liquid space of the accumulator. v

In'operation, phenanthrene vaporis continually formed from the liquid in the lower part of the accumulator, due to a slightly lower pressure prevailing in'the vapor space 22 than corresponds to the temperature of the liquid, which lower pressure is caused by the cooling eilect of the water in coils 24. The vapor formed di'sengages' itself at the liquid surface, rises through the outer connections 27, is condensed on coils 24, falls down into the lower part of drum 26 and is returned to the liquid space 21 through central connection 27. From elements 24 steam is conducted through conduit 31 to means for consuming steam such as turbine 30. Turbine is a high pressure non-condensing multiple stage turbine operating for example between 2000 and 300 lbs. per

- square inch, and discharging into intermediate pressure conduit 32 from which-consumers as, for. example, digester' 33 may receive steam. This turbine is provided with novel means for interstage superheating more fully described hereinafter.

Connected to the conduit 32 is a heat-exchanger 34 comprising an inner coil of pipe 35 and a casing 36. Steam passes from the conduit 32 through the coil 35 and into conduit 37, which supplies steam to a multiple stage condensing turbine 40 operating from about 300 lbs. to condenser pressure.

Phenanthrene vapor is suppliedto the casing 36 from the vapor space of accumu-v lator 20 by means or conduits 38, 39 and 41, and, surrounding the coil 35, heats the same to raise the temperature of the steam passing through so that said steam is superheated. To regulate the supply of phenanthrene vapor passing into exchanger 34 I have shown a valve 42, which may be controlled by means of a thermostat 43 placed in the conduit 37 and operating to maintain a constanttemperature in conduit 37.

through the same piping.

:nected with a diaphragm chamber 123, so

that when the temperature rises, the liquid expands and moves diaphragm 124 downwards so that valve 42 more or less closes,

limiting the flow of phenanthrenevapor into casing 36. Phenanthrene leaves exchanger 34 through conduit 44 and entersthe water economizer 45in which'feed water i'or the high pressure elements 24 is preheated. ln this economizer 45 I preferably decrease the temperature so that the phenanthrene a liquid of low ten'rperature, for example 250 1*.

Pump 46 driven by motor 47 withdraws phenanthrene'i'rom economizer 45 through conduit 48 and pumps the san'ie through conduit 49 into the phenanthrenc cconomizer 50 which is heated by means of products of combustion leaving the boiler 5 through line 51 controlled by .the damper 52. From economizer 50 the phenanthrene passes .through conduits 53 and 50 into the liquid space of drum 7.

The low pressure phenanthrene which is conducted to the accumulator 20 and therein condensed is returned from the liquid space of the accumulator to the liquid space of the primary boiler by means of motor driven. pump 54 and conduits 55 and .50. The pump 54 may be controlled in any manner so that a proper level of liquid is maintained in boiler 7. The liquidlevel in the accumulator may vary quite considerably depending on theditference between consumption and generation.

Several boilers may supply one accumulator. To illustrate this I have shown 'a second primary boiler 60 supplying phenanthrene vapor to conduit 17. In this case 1 have shown a horizontal return tubular. boiler. It is, of course, understood that the present invention is independent of the type of primary boiler used. If valve 125 is closed and valve 126 open the primary boilers 5 and 60 supply the accumulator Ifvalve 120 is closed and valve 125 open the supply from these boilers is independent. lhave shown be omitted.

' from the accumulator to the liquid'space'of By this means a uniform distribution of heat and a better operation of the boiler.

water space of the economizer 45.

' phenanthrene;

Furthermpre, since it re uires less time to fire u the type of boiler s own at 5, it may be advantageous to operate one or more boilers like continually and hold one or more boilers of the type of boiler 5 in reserve.

Means are shown whereby liquid can be kept in constant circulation between the accumulator and boiler 60. This comprisesa conduit 57 including a pump 58 driven by motor 59 and a conduit 61 including a motor driven pump 62. The first conduit with its pump are designed to conduct liquid phenanthrene from the boiler to the liquid space of the accumulator. The second conduit with its pump are designed to conduit liquid the accumulator maybe obtained. The conduit 57 with its pump is also extremely useful in firing up the boiler 60, especially when a liquid such as phenanthreneis used, since phenanthrene expands very rap dly as its temperature is raisedf Thus, in firing up a boiler, it has been found necessary to grad,- ually remove phenanthrene from the boiler as the temperature rises in order to maintain a proper level within the boiler. This may be done as shown in the present instance by conclucting the liquidthrough conduit 57 and'into the accumulator.

lVith a system designed as herein set out sure high boiling poinbphenanthrene.

I have shown twodiiferent ways of doing this. phenanthrene vapor is conducted to a superheat chamber 65 in which'superheat tubes are arranged to be heated by means of the vapor or by the liquid formed by condensation of'the same. From the high pressure stage H of turbine 40 the steam passes through conduit 66 and into header 67 from which it passes through U-tubes 68 into header 69 and.through conduit 70 into the intermediate stage From'the. ntermediate stage M the steam passes through conduit 71, into header 72, through U-tubes78 into header 74 and through conduit 75 into the low pressure section L. IjrOm' the low pressure section steam is conducted to condenser 76 from which the condensate is conducted byaneansof pump 77 into hot-well. -7 8. From the hot-well 78 water is conducted through conduit 79 and pump 80 into the The superheat tubes 68 and 73 are, as is thus seen, arranged to be fed in parallel by the In the superheat chamber the phenanthrene may be partly condensed.

The phenanthrene, whether vaporor liquid is conducted from the superheat chamber through conduit 81 to economizer 45 where In the instance of the turbine 40 of cleaning and repair.

of the tu'rbih eaiid preferablycontain tubes through which phenanthrene circulates.

Steam is supplied to the t'urbineifrom conduit.31 through conduit Admission to the first wheel03 is controlled by a mecha nism 92 comprising a series of valVes op-' e'ratlng successively in response to spcedof the turbine acting throug 1. the agency of "centrifugal governor 91, this control [being known. vAs is obvious, other forms of" controlmay be used in accordance with this invention. Steam after passing;- through the blades of the first Wheel enters 'channels94 which communicate with chambers 95. (Fig.

2.) Each otthese chambers is bordered by circular, portions 96 of themain-turbine.

casing. Partgoi' these circular portions 96 comprises covers 97 whichare secured by means of studs bolts 130 so that they may be readily removed to gain'access to chambers 95. Each of. the chambers is also bordered by two tube plates 98 between which.

and through holes of which tubes 100exte nl and into which the tubes are expanded orotherwise secured as by welding." Between tube plates 98 are formed an upper-inlet chamber 101, two side chambers 102, 103

and a lower discharge chamber. Chambers 101, 102, 10 3.and104 are in communication through the inside of tubcs 100. The-turbine casing is made in parts which are coupled together at the sides. .Tube' plates 98 are secured to ledges 105 forming part of the casing The Whole is arranged so that there .is no. communication or leakage 'between the space comprising chambers 101, 102, 103, 104- and the insidesof-tubes 100 on the one hand and the space chambers 95 surrounding tubes 100 on' the other hand.

The parts are so arranged that the covers 95 may be' removed and the tubes 100 and tube plate 98 removed as units for purposes The steam in passing through chambers 95 around tubes 100, is caused to be deflected by baflle plate 106 to assurean intimate contact of the steam with tubes 100.

Phenanthrene vapor is admitted to Challi her 101 through pipe 107 controlled for example by valve 108. This-vapor, then passes 109 and 110 into economizer 45.

.to both sides of the turbine, through'upper tubes 100, through chambers .102 and 103,' in parallel, through the lower groups of tubes 100 and into chamber 104'from which I the phenanthrene passes through conduits.

the above description superheats the steam as it passes from the one wheel to the next. 4 -The turbine 1s shown as driving a generator 111', with exciter 112 through reduction gear 113, although it may drive any apparatus.

Other superheating chambers 1'14 and 115 areshown between other stages of the turbine,' The arrangement of these'may be must follow the curve of heat consumption and the mode of heat production is simpli- The advantages of high pressure are well known. High pressure gives 'a more economical plant since practically no more heat need be applied to obtain higher, pressure. Fuel consumption is less per'.k w,. h. at higher pressure. The advantage of the inter-stage superheating in raising 'the chiciency of turbines and the longer life of turbine parts thereby acquired are known. The

value of heat accumulation so that heat "generation is independent of heat consumption is known. I have herein described novel means for producing these advantages and: i'orconibnnng them in a manner that givesgreater efficiency than has hitherto been possible. z

Boilers have previously been built of pressures up to 1200 and 1500 pounds per sq. inch pressure but in these constructions 'all of the boiler has been at the pressure of generated steam giving an undesirable arrangement. liable to leakage and other faults. My high pressure boiler is confined to one or more small elements preferably coils which give great strength without parts liable'to leakage since if there are joints, the type of joint necessary can be made tig-ht without difficulty. Furthermore I place the high pressure element in the va- -por space of the accumulator thus taking advantage of the higher rate of heat trans 'fer obtained by the condensation of the va or. Phenanthrene vapor condenses on the tubes, falls down'into the liquid space, and further. vapor is drawn to the tubes to be condensed, thus obtaining a constant circulation of heat transmitting medium past the condensing tubes. In thismanner I am able to reduce the high pressure steam generating surface to a very small percentage of the heating surface ofthe primary boilers 5 and 60.

The operation of the plant is obvious from the above description. Suppose, for example, that the load in circuit 120 increased.

steam accumulator filled with water.

aeeaaac This condenses more phena'nthrene' vapor in the accumulator. If more vapor is condensed than the quantity entering the accumulator, the pressure in the phenanthrene space thereof falls in a manner similar to a Howevelg there are many advantages in the accumulator of the present application over the ordinary steam accumulator. Here the pressure of steam supplied can be constant regardless of varying pressure in the accumulator. Furthermore the heat accumulated per cubic foot is about double that of the accumulator containing water. evident from the showing in Fig. 4 which is a diagram showing the corresponding temperature and pressure values of boiling of various liquids. Suppose no vapor is led from boiler 5 to the accumulator and only the accumulated-heat in the accumulator is utilized and that the pressure in the 'accumula'tor is 100 pounds per Square inch. The corresponding temperature isabout 900 F. Now water is led into coils 24 and phenani threuevapor condensed until the pressure in the accumulator is atmospheric. The temperature drop is then about 250 F. The temperature drop in water between the same values of pressure is about 125 F. Consequently it is seen that for these pressure values only one half as large an accumulator is necessary with phenanthrene as with water.- No accumulators are built outside the pressures here indicated wherefore this advantage may be said to be present in all cases.

In many cases it will make a cheaper construction, especially with the use of media which are more expensive than phenanthrene if the accumulator or the boilers are not only filled with a suitable liquid but also with solid material such as castiron. Ores. slacks of blast furnaces and certain kinds of stones can also be used for this purpose. This is indicated by reference character 131 in Fig. 3.

Further in the embodiment illustrated in Fig. 3 the steam generated in boilers 5 or is directly supplied to the vapor space of the accumulator and condensed by the liquid of the accumulator which for this purpose is drawn from the lower part of the accumulator by pump 117 through conduit 118 and forced through conduit 119 into the vapor space.

In Fig. 1 are shown valves 132, 133 and 13-1 and a bypass conduit 135, illustrating This is I that the phenanthrene may heat or superheat in series or in parallel. When valve 134 is closed, phenanthrene is supplied in.

parallel to heat-exchanger 34 and superheat chamber 65. .'When valve 134 is open and valves 132 and 133 areclosed phcn'anthrene passes in series through heat exchangerv 34 andsuperheat chamber 65. The latter ar rangement offers some advantagiesinsome cases 1n obtainlng more heat from the phe-' nanthrene especially in case it is jinconven ient to couple cooling apparatus such as the economizer 4'5 to the heat-exchanger.

Turbine 40 drives generator 136 coupled to circuit 120 in parallel to generator 111. Overflow valve 137 controls delivery of steam'to turbine 40. Turbines and maybe regarded as one machine with an extraction to digester 33, turbine 40 taking the steam not, used by the extraction consumer and being so constructed that it can receive all steam delivered'to the same and convert it into power. When consumer 33 draws a large quantity of steam, the supply to turbine 40 is momentarily decreased Wherefore the power delivered by the same to circuit 120 is decreased, wherefore the decreased revolutions of turbine 30 will cause a response of governor 91 to send more steam through turbine 30.

Although I have described phenanthrene as the preferred liquid, it is to be understood that the invention is not limited thereto but .may also use other'liquids such as naphthalene.

While Ihave described what is to 'my mind the preferred means for carrying out my invention, it is to be understood, that my inpendently of the supply of vapor thereto and under variations of pressure corresponding to variations in state of charge, a steam generating element situated in said accumulator and means to conduct Water to said steam generating element.

2. In a steam plant. incombination, a boiler containing a medium of high boiling point, said boiler generating vapor therefrom, an accumulator receiving vapor from said boiler, and condensing the same, a steam generating element heated by vapor formed in said accumulator and means to supply Water to said steam generating 'ele-' ment.

3; In a steam plant, in combination, a boiler containing a fluid of high boiling point relative to water, an accumulator, means to conduct said fluid from said boiler to said ac cumulator, means to conduct said fluid from said accumulator to said boiler, a steam generating element. situated in said accumulator, and means to conduct water to said steam generating element.

.4. In a steam plant, in combination, a. boiler containing a fluid of high temperature at low pressure 'and operating at a rate corresponding to the rate of supply of heat thereto, an accumulator, means to conduct said fluid from said boiler to said accumulator, said accumulator operating independently of the rate of supply of fluid thereto and under variations of pressure corresponding to variations in" state of charge thereof, means to conduct said fluid from said accumulator, a steam generating elementheatcd by vapor formed in said accumulator and means to supply water to said steam generating element. a

5. In a steam plant, in combination, a boiler containing a fluid of high boiling point, said boiler generating vapor therefrom at a rate corresponding to the rate of supply of heat thereto, means to maintain constant pressure in said boiler, an accumulator receivlng vapor from said boiler, said accumulator operating independently of supply of vapor'thereto'and under variations of pressure. corresponding to variations of state of charge thereof, a steam generating element situated in said accumulator, and means to circulate said fluid through said boiler and said accumulator.

6. In a steam plant, in combination, a boiler containing a medium of high boiling point, said boiler generating vapor therefrom at a rate correspondingto the rate of supply of heat thereto, an accumulator having a liquid space and a vapor space, means to conduct vapor from said boiler to the liquid'spaceof the accumulator, said accumulator operating independently of supply of vapor thereto and under variations of pressure corresponding to variations of state of charge thereof, a steam generating element situated in the vapor space of said accumulator and means to supply Water to said steam generating element.

7. In a steam plant, in combination, a boiler containing a medium of high boiling point, said boiler generating vapor therefrom at a rate corresponding to the rate of supply of heat thereto, an accumulator having a liquid space and a vapor space,-means to conduct vapor from said boiler to said accumulator, said accumulator operating independently of supply of vapor thereto and under variations of pressure corresponding iao 6 ment.

8. In a steam plant, in combination, a boiler containing a medium of high boiling point, said boiler generating vapor therefrom at a rate corresponding to the rate of 10 supply of heat thereto, an accumulator having a liquid space and a vapor space, means to conduct vaporfrom said boiler to said accumulator, said accumulator operating independently ofasupply of vapor thereto and it under variations. of pressure corresponding -to variations of state of charge thereof,

means to returnliquid from said accumula-.

tor to said boiler, and means'to enerate steam by condensing'the vapor in said accumultator.

9. In a steam plant, in combination, a boiler containing a medium of high boiling point, said boiler generating vapor therefrom at a rate corresponding to the rate of supply of heat thereto, an accumulator havmg a llquid space-and a vapor space, means to conduct vapor from said boiler to said accumulator, said accumulator operating independently of the supply of vapor thereto and under variations of pressure corre'spond ing to variations of state of charge "thereof, means to return liquid from said accumulator to said boiler, a pipe-coil situated in the vaporspace of said accumulator means to as supply water to one end of said coil and means to withdraw steam from the other end of said coil. I

1(L' Accumulator apparatus for steam plants comprising a receptacle containing a 40 medium of high boiling point and having a liquid space and a. vapor space and operating under variations of pressure corresponding to variations of state of charge thereof, a drum connected to sand receptacle and filled with the vapor thereof, a steam gener-' ating element situated in said drum, said steamgenerating element comprising a coil.

11. Accumulator apparatus for steam plants comprising a receptacle containing a 0 medium ofhigh boiling point and having a liquid space and a vapor space, a steam drum situated above said receptacle, a steam gencrating element situated in said drum, connections establishing communication between said receptacle and said drum and means to supply water to said steam generating element.

12. In a steam plant. in combination, a

boiler containing a medium of'high boiling point, said boiler generating vapor therefrom, an accumulator, means to conduct vapor from said boiler to said accumulator, a steam generating element heated by vapor formed in said accumulator, an economizer means to conduct water through said econ- Leeaaae omizer and into said steam generating element and means to heat said economizer by vapor Withdrawn from said accumulator.

13.'In a steam plant. in combination, a boiler containing amedium of high boiling point, said boiler'gencrating vapor therefrom at a rate corresponding to therate of supply of heat thereto, an accumulator re ceiving vapor from said boiler, and condensing the same, said accumulator operating independently of supply of vapor thereto and under variations of pressure corresponding to variations in state of charge thereof, and a superhcating element heated by vapor formed in said accumulator.

14. The method'of generating. high pressure steam which comprises vaporizing a mediumof high boiling point at a substantially uniform rate, condensing, the vapor produced in liquid'of the same medium, storing heat in said liquid and producing vapor therefrom and condensing-the-same in proportion to steam demand by the cooling effect of water to such an extent that the water is vaporized toform steam 'of-high' pressure. 4 a

15. The method of generating high pressure steam whichcomprises storing heat in a medium of high boiling point. producing vapor thereof in proportion to demand. for steam by the cooling effect of water and condensing said vapor by said water, thereby producing steam of high pressure.

16. In a steam plant, a receptacle containing a medium of high boiling point and in boiling condition. and having a vapor space above the medium of high boiling point, a

steam generating element situated in said receptacle in said vapor space, means to supply heat to said medium, means to supply water to said steam generating element, means to withdraw steam from said element, the said receptacle being of such size and containing said medium in such quantity that large variations in pressure may take place by the cooling effect of water in-th steam generating element.

17. Accumulator apparatus for a steam plant comprising a receptacle containing a medium of high boiling-point and having a liquid space and a vapor space. meansto vary the heat content of said medium in accordance with variationsin supply of heat to the plant, said receptacle operating under variations of pressure corresponding to variations in state of charge and means togenerate steam by condensing the vapor in said receptacle in accordance with demandrfor steam.

18. Accumulator apparatus for a steam plant comprising a receptacle containing a, medium of high boiling point and having a liquid space and a vapor space, means to vary the heat content of said medium in accordance with variations in supply of phenanthrene,

producing rapor thereof in accordance with demand for steam byihe cooling effect vapor by sa steam of high Intestimon s gnature.

and oondens'in said thereby pro ucing of water 1d Water pressure.

y whereof I hereunto aflix my JOHANNES RUTHS.

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