US898610A - Steam-calorimeter. - Google Patents

Description

C. C. THOMAS.-

STEAM CALORIMETER.

' APPLIGATIDH rum SEPT. 29. 1906.

Patented Sept. 15,1908.

2 SHEETS-SHEET 1.

wiwi G. C. THOMAS.

STEAM GALORIMETEB.

AYPLIGATION FILED SEPT. 29. 1906. 898,610. Patented sept. 15,1908

2 SHBBTS-SHBET 2.

ATTORNEYS INVEN'R BY n l.. A d

WTNESSES:

Pagani? onirica.

CARL C. THOMAS, 0F ITHACA, NEW YORK.

STEAM-CALORmETER. y

Specication o! Letters Patent.

Application led September 29, 1906. Serial No. 336,756.

To all whom 'itma'y concern: Y

Be it known that I, CARL C. THOMAS, a' citizen of the United States. residing at Ithaca, in the county of Tom kins and State of New York, have invente certain new and useful Improvements in Steam-Calorimeters; and I do hereby declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to' which it appertains to make and use the same.

My invention relates to .improvements in steam calorimeters, and comprises means whereby the proportion of moisture present in steam at any given instant may be determined readily.

My improved calorimeter is adapted for the same uses as ordinary steam calorimetels, but is articularly intended for analyzing the pe Vormance oi steam turbines, for which use ordinary steam calorimeters are not well adapted and for which use there has not heretofore beer. any suitable instrument.

In steam turbines to which is supplied dry but unsuperhcated steam, or steam which, though initially superheated, has not such degree of superheat that it does not become wet during lts passage through the machine, the moisture present in the steam-at any particular point in the turbine bears a directY ratio to the amount of work done by the lsteam in the turbine up to that point.. If

the steam supplied to the turbine be either moist or superheated', a suitable correction mav be required, but such correction 4is easily made. By determining the quality of the steam (which is the term used by enginee-rs in referring' to the percentage of moisture carried by steam) at a number of different points in the turbine, and plotting the results thus obtained, an accurate indication of the performance of the turbine is obtained.V In fact, by so using a calorimeter, the performance of the turbine may be investigated and analyzed as readily as t 1e performance of a reciprocating steam engine may be investigated and analyzed by meansV of a steam engine indicator. Y

The calorimeter herein illustrated and described is designed to be attached successvely at different ints along theca'sing oi a steam turbine wh the said turbine is running under substantially constant conditions,

and to draw oiwsamples of steam from such turbine at the'varicus points at Jvghich it is connected, and to show the quality of the.

steam of each such sample. To indicate the quality of the steam of such samples I adopt the expedient of heating the steam to remove the moisture and determining the amount of heat required (in proportion to the rate of passage of the steam through the calorimeter) to bring the steam to absolute dryness. This I do preferably by means of an electric current passing through resistance coils past which the steam is caused to How. By determining the rate of iicw oi the steam through the calorimeter (very simple means for doing this with great accuracy will be described hereafter) and by measuring the amount of electrical ener y absorbed in bringing this steam to absolute dryness (an indicating ammeter or watt meter and a thermometer to indicate rise of temperature of steam above that of unsu erheated steam at corresponding pressure wi l show this) the observer obtains readily the percentage of moisture in the sample of steam tested.

It Will be seen that a calorimeter operated Von this principle gives continuous readings, and from each set of readings the quality of the steam tested at Ithe particular instant the reading is taken may be determined without reference to previous readings. Furthermore, the accurae ci the instrument is not dependent upon t e mechanical removal of all traces of moisture from the sample of steam tested (a matter of reat difficulty or upon observation of weillit of steam condensed, (a somewhat rougir and slow method givin accurate results onlv in the hands of skili 'and experienced observers and requiring bulky aplparatus). The accurate determination or' t. 1e temperature of steam by means of accurate or accurately calibrated thermometers or equivalent temperaturemeasuring instruments, is a very simple matter; andthe temperature of saturated steam for different pressures having already been accurately determined and bein" shown in various published steam tables, the slightest rise of temperature of the steam tested above that of saturated steam at corresponding pressure, as shown by steam tables, indicates that the steam tested has been completely driedl and. superheated to the extent of the excess of the thermometer reading over the temperature of saturated-steam at the correspending pressure. :y

Owing to tho great facility with which the flowpf electric current through the heating ecoils of the" instrument may be regulated.

- Patented sept. 15, 190s.

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such {.cgree cf superheat ii; the instrument should always be ver): slight, and should be substantially the salueat all times, and will ordinarily be negligible. But. if desired, correction for such superheat. may be made readily, as will be obvious to those skilled in the. art.

My invention consists in a calorimeter' comprising means for heating the steam tested to dryness, and for observing the amount of heat required 'for such purpose; in the general construction ol the instrument; and generally in the features hereinafter described and particularly pointed out in the claims.

The objects of my inventionare to analyze the performance or' -steam turbines; to improve and simplify steam calorimeters; to make the calorimeter adaptable for any class of work for which .steam calorimetersare commonly used; to providea calorimeter adaptable to the determination of the qualit)Y oi' steam in difiere-nt portions of a steam turbine; and to make the. inst mlment simple,

' compact, accurate and reliable.

I will now proceed to describe my invention with reference to the accompanying 'd "awnings, in which one form of calorimeter embodying my invention is illustrated, and will then point out the novel features in claims.

1n the said drawings: Figure 1 shows alongitudinal vertical section of myimproved calorimeter on the irregular line :t1-.r of Fig. 2, a portion of a turbine being also indicated diagrammatically with the calorimeter attached thereto. the calorimeter and indicates particularly the location of the discharge and pressure gage connections, and the circuit terminals. Fig. 3 shows a transverse horizontal section through the heating chamber of the calorimeter, and indicates means which may be employed for causing the stream to pass in close. proximity to the heating coils. Fig. 4

is a diagrammatic view illustrating my said calorimeter attached to a turbine (the latter indicated diagranmistically) with pressure gage and electrical connections. Fig. 5 is a. view similar to Fig. 1, illustrating an alternative construction of my improved calorimeter. Y

Referring now to the accompanying drawings and atiirst to Figs. 143 inclusive, l des 7 ignatcs the casing of the. turbine, 2 a portion of the rotor of such turbine, and 3, 3 and 4, 4 blades of the casing and rotor respectively. 5 designates the said calorimeter. lt comprises a hollow casing arranged to be connected to an orilice in the casing of the turbine by a threaded ni iple 6, provided with a sampling tube 6. 'l`lie top ol this casing is closed by a head 7 provided with cin-:llt terminals and with a passage for the outiiow of the steam, and with means for admitting a Fig. 2 shows a. top View of= vcoils 1 1 thermometer and for the attachment of a steam gage, all as hereinafter described.

lVitliin the casing ol the calorimeter is a cylinder .s ot' electrical insulating material adapted to withstand the temperature of the steam (soapstone is one material suitable for the purpose) having within it a series of longitudinal perforations t) extendingr from end to end and containing the resistance hea ting These coils are electrically conneet-ed to each other and as a whole are connec-ted to circuit terminals 12 and 13-carried by the head 7. The cylinder 8 has a central bore 14 extending from one end to the other, the upper portion of said bore enlarged and screw-threaded to screw over the end of a depending neck 15 forming a part of the head 7` ot' the calorimeter casing; whereby the said cylinder is supported. At. its lower end said cylinder 8 carries a cap 1G screwing upon the lower end of said cylinder, and between said cap and the -lower end of said cylinder 8, there are a number of screens or diaphragms of wire gauze or the like 17, and anerl'orated plate 18 forming a backing there or. Lugs 19 projecting from the sides of the casing of the calorimeter steady the cylinder 8 at its lower end; and between said lugs the steam passes upward around the cylinder to the upper end thereof, and thence through the passages 9 in said cylinder to the lower end thereof and through the plate 18 and screens 17 and the internal bore 14 of the cylinder S, u i through the internal bore 20 of the head 7 el the calorimeter, and out through discharge passage 21. At. thc end of said di:- charge iassagc 21 I provide a pl. having in it a calibrated orifice 22, and beyond said plate there is a discharge cham'oer 23 leading to a condenser or to the atmosphere or to any other suitable discharge. A pressure gage 24 connected to the calhrimeter at 25 serves to show the pressure at which the steam is discharged from the calorimeter. By means of this steam gage .24 and calibrated orilicc 22 the rate of tlow of steam through the calorimeter may be determined instantly and with great accuracy; since the rate of llow of dry steam through a small orilice at constant pressure is very uniform. Chamber .23 is provided with a connection 2S for the at,- tachment of a pressure or vacuum gage, mercury column, or the like.

26 designates a long thermometer cup inserted through a stalling box .27 at the top of thehead 7, and n'ojecting downward nearly to the bottom oll the cylinder 6. By means of a sensitive thermometer .28 (Fig. 4) placed in such a tube, it is possible to measurt` with great. accuracy the temperature of the steam passing through the calorimeter. As will be readily understood, the temperature ot' unsuperheated steam is. independent of the amount, of moisture carried by it, and l'or tht` same pressure is always the same. 'lhe published steam tables give the tenperature of l pressure of steam entering the calorimeter unsuperheated steam through a wide range of preurcs. The temperature of steam cannot rise above that corresponding to the pressure exist' at the moment, until the moisture susp'en ed in the steam shall have been eva orated and the steam is absolutely dry. A s ight indication in a thermometer placed within thermometer cup 26 of a temperature above that of saturated steam of tne ressure of the steam in the calorimeter, s lows that .all suspended moisture in the steam has been evapoated and that superheat of the steam has commenced. Instead of usin pressure gage 24, or vas a check thereon, may provide a thermometer cup; 3'] (Fig. 4), exposed to the steam as it enters the calorimeter. A thermometer placed in this cup will. show the temperature of the .entering steam, and from this the steam pressure may be obtained by referring to steam tables.

In Fig. 5 I illustrate an alternative construction of calorimeter, in general similar to that shown in Fie. 1, except in the details of construction and` arrangements hereinafter mentioned. `The soapstone cylinder 8 is provided with a shoulder 31 resting upon a corresponding shoulder of the outer casing 5 of the calorimeter. y Outside this shoulder 31. is placed packing material 32, and a gland 33 screwing into the casing 5,' compresses such packingl material. In this'form of calorimeter, the steam passes upward through the passa es 9 containing the heating coils 11, into t ie chamber 34 above saidl soapstone cylinder, and thence passes down through the central bore 14 of this cylinder. 1

Within said bore, but su ported from the top 7 of the calorimeter, t ere is a tube 35, open at the lower end; and around the lower portion of this tube 35 are Wrappings of gauze 36. The steam passes down through the annular space surrounding this tube 35, and through the gauze 36, whereby said steain'is thoroughly distributed, and thence asses u through the inside of tube 35, in t ie annu ar space between the inner wall of said tube and the thermometer cup 26, thence passing out through discharge chamber 23.

The form of calorimeter illustrated in Fig. 5 is preferable to that shown in Fig.. 1, in that it is somewhat easier and simpler to construct. ,f

Sometimes, instead of employing ressure gage 24 to show that pressure at w ich the steam passes through the calorimeter, or as a check upon the pressure gage, I provide a thermometer cup 37 connecting so as to receive steam at the same pressureV and temperature as the steam entering the calorimeter, and in this cup place a thermometer 38. It being always possible to determine the pressure of unsuperheated steam, from its temperature, the thermometer 38 shows the as accurately as, and perhaps more accurately than, the pressure gage 24, and is furthermore a lighter and more compact piece of apparatus.

In Fi 4, 29 desivnatcs an instrument by which t e current flowing through the. coils of the calorimeter at any instant may be measured. In using this calorimeter in testing a steam turbine, the calorimeter is connected successively at di'erent points along the path of steam throu h the turbine, one such point being preferah y before the steam encounters the blades, and another after it has passed the last blades of the turbine, the

-other points being intermediate these two.

In turbines ofthe Parsons type, for example,

the calorimeter will customarily be connected successively to passages connecting the several rows or sets of casing blades. The quality of the steam withdrawn through the calorimeter at each such point of connection being determined, and the results plotted, a curve is obtained showing the qualit of the steam at each point of its passage t irou h the turbine and thus the rela.- tive work r one by the steam in each portion of the turbine is indicated. In determining the`quality of the steam, the steam test-ed flows through the inlet 6 of the calorimeter, around the cylinder 8, and thence throuvh the assages 9 in said cylinder, over 'the heating coils 11 therein,to the central passage 14 (around the thermometer `cup 26) and thence through the calibrated orifice 22 outward. Electric current'is -passed through the coils 11 in quantity suiiicient to impart heat to the steam and as soon as it is known that the parts of the calorimeter are at the -temperature of steam and therefore are not causinv condensation, the flow of current is carefully regulated so that any slight increase o current flow will raise the tem rature of the steam, as indicated by the tli iometer `cup 26, above the temperature of unsuperheated steam at thepressure shown on the pressure. gage. The amount of current thus re uired to drive the steam-being known, and t e rate of passage of steam passing through the calibrated orifice 2,2 being known, itl-becomes a simple matter to calculate the number of heat units required to dry any convenient unit of steam and thence to determine `thexamount of moist-ure in the steam...: Si if The sampling tube 6 will be of a shape, construction etc., adapting it to take a fair samplel of the entering steam. The use of sampling tubes in connection 'with steam calorimeters is well understood, and I have not attempted to illustrate any particular construction of such tube.

In order to insure passage of the steam in closp proximity to the heating coils, Isome- ,los

iso

times provide iilling pieces such as the pieces 3U shown in Fig. It, in the sieain passages 9 containing the heat ing coils 11. 'lhesetilling pieces till the central portions ofthe passages 9, forcing the steam to pass directly over thcscribed` have not been used before, to my knowledge; nor have electrical resistance coils been employed before in such calorimeteis to diy the steam, t-o my knowledge. By means of these resist-ance coils, it is possible to regulate the. heating of the steam with great. nicetj; and to determine azcurately the amount of heat imparted to the steam; for it is an easy matter to measure accurately the .elect-ri :al energy converted into heat in the instrument, the instrument employed for the purpose (an aiiiineter or wat-tineter) being Very portable'and easily read, and being in its nature capal-ile of great,v accuracy. The calorimeter constructed as shown is substantially {re-e from features which are aptto lead to errors, uncertainty or inaccuracy in results. i

lVhe-n in operation the exterior of the caiorimeter will be covered, lagged, or otherwise protected from heat radiation as is customary with suc-h instruments.

While 1 have shown the calorimeter attached directly to the turbine, it ill be understood t-liatitl may be attached by means of suitable and convenient pipes, valves, etc., such as are commonly used in connecting caloriincters to -tlie source ot supply ot' steam to be tested.

Instead of coils of resistance Wire, any

' other suitable resistance material muy be used in the caloriiiietei.

What l claim is2- l. A stoam calorimeter adapted to permitthe tiow of steam therethrough, and coinprising electrical heating means, and electrically-operated measuring means for measuring the energy used. .Y

2. A steam calorimeter adapted to permit. the flow of steam therethipugli, and coinprising electrical heating means, electricallydetermining means and steaiii-distrilinting operated measuring means for measuring the energy used, and means for measuring the rate of low of steam through the calorimeter.

3. In a steam calorimeter, the eombiiiation with a chamber adapted to permit the flow of steam therethrough` 'if an electrical heat-ing coil iiisaid chamber in the direct path of the steam, and means for measuring the energy used.

sf.- y sessie 4. Iii a'steam calorimeter, the combination with a chamber adapted to permit the tloxv of' steam lherethrough, of an electrical' heating coil in said chamber in the direct.- A

path of the steam, means for measuring the energy used, and means for measuring the rate of tlow of steam through said chamber.

5.. In va steam calorimeter, t-he combination with a ehiniber adapted to permit the flow of steam therethrough, of an electrical hea-ting coil in said chamber, means ior measuring the rate of flou of .steam through said chamber, and means for measuring the tion of current through said coil.

6. In a. steam calorimeter, the. coinbina tion of a chamber adapted to permit the ilo of steam therethrough, a support of insulating material wit-hin said chamber, and an electrical resistance coil on said support, saidV support having meanstor distributing the steam and for passing all. warts ofsame in close proximity to said coil, and means for measuring the flow of current through said coil.

7. In a steam calorimeter, the combinat-ion of a chamber adapted for the loiv of steam therethrough, a body of insulating material therein. having passages therethrough for the flow of steam, and resistance heating coils in said passages in the directpath of the steam. 8. In asteam calorimeter, t-he eoiiibination of a chamberadapted for the tloiv of steam therethrough, a body of insulating material therein suspended from one end, where by expansion of said chamber relative to said body of insulating material is permitted, and heating coils carried thereby.

9. In a steam calorimeter, the combination of a chamber adapted for the flow of steam therethrough, and means Within said chamber comprising a passage for the low of steam and a heating coil in said passage in the direct )ath o the steam.'-

10. ln a steam calorimeter, the combina-A tion of a chambcr adapted for the ilow of steam therethrough, means therein, having a paassge for the-flaw of steam` and a heating coil in said passage., in t-lie direct path of the` steam iassiiig through such passa gc.

1l. ln a steam calorimeter, the combination of a chamber adapted to permit the llmv of steam therethrough, a heating coil therein, in the directpath of the steam, temperatureineans interposed in the path ot' the same between said heat-ing coil and tcinpcrature-dc-- eeslo l steam, andsteam distl'ibuting-means interposed in the path of the steam between said temperature determining means and said coil.

13. In a steam calorimeter, the combina-y tion of a chamber adapted to permit the ilow of steam therethrough, means therein provided with a passage for the i'low of steam and with a heatiiig coil in said passage, means for determinatonieif the temperature of the steam, and foramincus metal interposed between said coil and temperature determining means.

14. In a steam calorimeter, the combina tion of a chamber adapted to permit the flow of steam therethrough, means therein provided with a passage for the flow ci steam and with a heatin coil in said passage, a thermometer cun eyond said heating coil, and

steam distri uting means between said cup and said heating coil.

15. In a steam calorimeter, the combination of a chamber adapted to permit the flow of steam therethrough, and a body of insulatin material therein provided with electrice heating coils and with a thermometer I. In a steam calorimeter, the combination of a chamber ada ted to permit the flow of steam therethrougi a 'bony of insulatin material therein provided with electrica heating coils, a thermometer cup, and steam distributing means surrounding said cup..

17. In a steam calorimeter, the combination of a chamber adapted to permit the iiov.' of steam therethrough, a body of insulating material therein provided with electrical heating coils, a thermometer cup, and foruminous metal surroundingsaid cup.

18. In a steam calorimeter. the combination of a chamber ada )ted to permit the ilow of steam therethrough, a perforate support within said chambery havmg holes for the iow of steam and heating coils therein and having another hole therein for the return ilow of the steam, a tube therein leading to the discharge of said chamber, and means` in said tube for determining the temperature of the steam.

19. In a steam calorimeter, the combination of a chamber adapted. to permit the flow of steam therethrough, a pcrforatc support within said chamber having holes for the flow of steam and heating coils therein and having another hole therein for the return ilow of the steam, a tule therein leading to the discharge of sai hlmmbcn means in said tube permitting determination of the temperature of the steam, and distributing means for distributing the steam prior to contact with said temperature determining means.

20. In a steam calorimeter, the combination of a chamber adapted to permit the flow of steam therethrough, a periorate support within said chamber having a steam passage, and a heating coil therein, and having ruso another passage, a tube within said latter passage, foraminous material surrounding said tube, and means within said tube for determination of the temperature of said steam.

21. In a steam calorimeter, the combination of a chamber adapted to permit the flow of steam therethrough, a perforate support within said chamber having a steam passage, and a heating coil, therein, and havin also another passage, a tube within said atter passage,Y oraminous material surroundin said tube, and a thermometer cup within sai tube.

22. In a steam calorimeter, the combina- 'tion of a chamber adapted for th'cilow of steam therethrough, a body of insulating material therein having a passage for the flow of steam, a heating coil in such passage, anita iiiling piece in such passage arranged to cause thel steam to pass in. close proximity to said co1 In testimony whereof I affix my signature,

in the presence of two witnesses.

CARL c. mortis.

- Witnesses: Y

DEXTER S. KIMBALL, ALBERT W.Snrrn.

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