US989723A - Turbine. - Google Patents

Description

R H. RICE.

TUHBlN'.

AFPLwA'l'wN NLM MIG. 5, isms.

989, '723. Patented Apr. 18, 1911.

2' re InVelflizOf', Richer-d H.F?ic:e

Atty. y

'with that desired :tor

unirsi) srarnswagnn'r onirica.

RICHARD RIC, 01? LYNN, MJSSACHUSETTS, ASSIGNOB, T0 GENERAL ELECTRIC OMPANY, fa. CORPORATION YORK.

Specification of Letters Patent.

latented Apr. 1S, 1.911.

Application filed August?, 1909. Serial No. 511,309.

,citi/:en of the United States, residing ,at

Lynn, county of Essex, State of lllassachusetts, have invented certain new anduseful Improvements in Pressure Maintaining Mechanism for Turbines Supplying Steam for n[nd ustrial Purposes, of which the following is a specification.

This invention relates to elastic-fluid tur! bines, and especially those from which low pressure steam is drawn to supply 'industrial apparatus ol various kinds, such as heating appliances, dye liettles, and the like. In such a plant, the demand for low pressure steam may vary between wide limits and quite independently oi the power load on the turbine. Indeed, it may happen that the mill load may be at a maximum when the power load is at a maximum, or vice versa. From this it follows that the ordinary mechanism which merely governs the admission of steam to the turbine in accordance with the power load must be supplemented by some device which will, independently taire into account the demand of the mill for .low pressure steam, so that both the power load and the mill load will be ellcctively handled, each independently of the other.

In carrying out my invention; a4 Curtis multi-stage turbine is preferably employed. At some place iii the working passage or theA turbine where the normal pressure at, say, full load corresponds approximately the auxiliary devices, a conduit is led oil' to supply steam to said devices. It is very desirable, however, to maintain a constant pressure in these devices irrespective of the volume consumed, and since the pressure in any given region ot' a turbine varies greatly under different con-- ditions oit the power load," provision must be made .tor maintaining the constant pressure required by the mill, and this must he done under variations not only of the power load but of the mill load aswell.

The present invention is a modifi :ation or the apparatus set forth in the application ot liewis flauders, tiled April Q2, 1900, Sieria'l No. 4iSS),5]7. it comprises a pilot valve crmtrollirrsr nozzle valves between the constunt pr ure 'ion or storie ot the turbiru, and the stam i 'with a revice responsive to Vvariai.ions in the volume of the i am witlulrawn for mili purposes, and a novice responsive to the pressure in said steamsupplying region or stage; both of these devices exerting control over the pilot valve. From this-1t results that any variation 1n the volume of the steam Withdrawn or in the pressure in said stage will be counteracted by the opening or closing of the nozzle valves, thereby relieving or building up the stage pressure, as the case may be, in order to maintain it as nearly constant as possible. The apparatus is hereinafter set forth in detail, and will be readily understoodupon reference to the description, taken in connection With the accompanying drawings, in 'Which- Figure l is a diagrammatic representation of a turbine equipped with my improved pressure-maintaining apparatus; and Fig. 2 is a sectional plan vieiv, on a smaller scale, taken on the line 2-2, Fig. 1.

The turbine shown is simply illustrative,

as the particular design isnot essential. I`

have shown an upright Curtis multi-stage turbine having its bucket Wheels l secured to the shaft 2 and carrying two sets of buckets 3 cooperating with stationary intermediates l and taking steam from suitable steamchest nozzles 5. rlhe severa-l stages are separated by rdiaphragme 6.

From one of the chambers 7 into which the steam exhausts from one of the stages, a steam pipe 8 leads to heating` apparatus of some kind, such as a dye kettle, a steam table, or other mill appliances. In this pipe is included a device sensitive to changes in the volume of fluid flowing througlrit. This consists preferably of a float 9 moving axially in a conical enlargement l0` of said pipe and attached to a red il which passes ou/t through a stalling box l2. YVhen the volume et steam4 dra-wn cli bythe heating apparatus increases, the iioat is moved up- Yardlyvand vice versa. vI provide one or more stage nozzles i3, controlled by valves 11i located in auxiliary passages 15 leading from the chamber 7. These valves are held closed by springs 16, but can be opened by fluid ressure acting,l on pistons 17 Working in cylinders 1S in oil'iposition to the tension oi 1' springs. The, valves,"springs, pistons and cylinders are contained in easings lg'semirerl 'to the casing' 2O of the turbine. llach casina; i9 is connected by a pipe 2l to a "-a'alre chest E32, Vthe several pipes entering said chest at different distances from the vpivoted to the rod 11 01"' the float 9.

pipe 2o which supplies hydraulic or other I fluid pressure to said chest. At the oth r end of said chestan exhaust pipe Qft, and. in said chest moves a pilot valve 25 adapted to open one or more of .sa-id pipes to the supply or the exhaust as the case may be. The valve stem 26 is pivoted to the middle of a 'Heatinglever 27 which at one end is The other end of said lever is pivoted to a rod 28 which is attached. to a movable abutment exposed to the pressure of the steam in the chamber 7; preferably a piston 29 working in a cylinder 30 and urged upwardly by a spring 3l. l Apipe 32 connects the upper end of said cylinder with the chamber 7 of the turbine. The tension of the spring'just balances the thrust of the piston when the pressure in the chamber 7 is at its normal value,

The operation is as follows: The iloat`9 is of constant weigh t, and by'virtue thereof it rides or floats on the current of steam flowing through the pipe 8. There is a certain pressure diferenoe between the upper and lower side of the float depending on the area 0I" t-heannular opening around it. This pressure dill'erence, multiplied by the area of the float, is just suiicient to balance its Weight. When an increase in, volume occurs, the pressure difference increases and the float rises and increases the annular open-y ing around -ituntil the pressure ditferenee is reduced to the normal value again, and the loat comes to rest in this new position.. In other words, the float automatically ad juste itself up or down to maintain a constant pressure difference between its upper and lower sides. Now let it be assumed that the power load on the turbine is steady, and that one or more additional mill appliances, are put into use, calling for a greater flow of steam through the pipe'. This tends to lower the pressure in lthe chamber 7. The greater volume raises the float 9, which lifts the pilot valve 25, shutting ott' pressureirom one or more oi the pipes 21 and causing the closing; of one or more of the stage nozzles 14. This results in decreasing the steam outlet at the nozzles to a degree sufficient to compensate for the increase in such outlet due to the lifting of the lloat, and the steam pressure in the chamber 7 is, therefore, r e stored to normal in spite of the increased volume now flowing from said chamber. On` the other han'd, it some ot the mill appliances are shut down, so that a lessened volume of steam is required, the float 9 will fall, but this causes the opening ot one or more nozzles, and thus prevents any increase of the pressure in the chamber 7. Again assume a constant mill load, but let there b'e un increase in the power load. The turhine ,ejoijerimr at once opens moresteamchest nem/lcs, a-Llmitting a larger volume oi' seams steam to the t urbine and thereby raising the stage pressures. 'lhc increase in pressure in the chamber 7 tends to produce a greater flow through the pipe S and thereby lift 'the tloat, but the piston 29 is forced downwardly by the increased pressure, thereby pushing' down the pilot valve and opening enough nozzle valves to relieve the extra pressure in the chamber 7 and bring it down to normal. lilith a lessening' of the power load, an opposite e'tlect is produced. lt appears, tlieret'ore, that under all conditions, whether of valfying the mill appliances, or of fluctuations in the power load, my apparatus maintains f practically constant pressure Iot steam in that stage, chamber or Jregion oi the turlgiine which supplies said mill appliances.

l n accordance with the provisions of the patent statutes, lhave described the principle ot operation oi my invention, together with the apparatus which l now consider to represent the best embodiment thereof; but l desire to have it understood that the apparatus shown is only illustrative,l and that the invention can be carried outby other means.

llVhat I claim as new and desire to .secure by Letters Patent of the United States, is L l. The combination with a turbine, of a pipe taking steam from a low-pressure region therein, and means governed by the tiow 'of steam through said pipe for controlling the pressure in said region.v

2. The combination with a turbine, of a pipe takingl steam from a low-pressure stage therein, valves controlling the tlow of steam from said stage to the next, and means controlled by the ilow of steam through said pipe for opening and closing said valves.

3. The combination with a turbine, of a pipe taking,y steam from a low-pressure stage therein, valves controlling the llow of steam trom said stage to the next, a i'ioat in said pipe, and operative connections between said lloat and saidl valveA .f-i. rlhe combination with a turbine, oi a pipe taking steam from a low-pressure stage therein, a conical enlargement in said pipe, a' float in said enlargement, and means actuated by said float for maintaining a constant pressure in said 5. rlhe combination with a turbine, ot' a pipe takingl steamtrom a. lowfiressure stage therein, a movable abutment exposed tothe pressure in said stage, a {loat in the pipe that is controlled by the flow therethrough, and valves controlled by ,said abutment and lloat for regulating' the flow of steam from said stage to the next.

` G. The ciuul'iination with a turbine, of a pipe taking steam from a low-I ncssure stage therein, a device responsiveI to the volume ot steam ilowinir through said pipe, a device responsive to the pressure in said stage, and` demand for steam byiool means controlled in common by both seid devices for maintaining constant pressure 11'1 said stage.

7. The combination with a turbine, of e pipe taking steam from e lovwpiessui'e etage therein, a, device responsive to the volume cf steam How/'ing through seid pipe, e device iesponsive to the piessuie in said stage, e Heating lever connected with both of seid devices, and valve mechanism connected Witli. seid lever anni serving to maintain constant pressure in said stage.

8. Thecombination with :t turbine, of :1 pipe taking steam from e.. loW-p1'essure stage therein, iuid-pi'essni'e operated valves centiolling the flow oiE steam from seid Stege to the nent2 a pilot valve contioliing seid valves, and devices respectively espensive to the flow in seid pipe and te the peessu'e in the etage from which Tooth eff seid devices exerting 'e control upon said' pilot valve.'

9, |The combination with a turbine, of a pipe taking steam from e, 16W-pressure stage theiein, ud-pieseure operated valves eenu trolling the ow ot' steam from siiici Stege the next, e pilot valve eontioiling sse-id valves, a floating lever attached to Said pilot valve, e Hoetin seid connected to one end of seid leveif and e Spring-pressed, abutment connected to the other enel of seid lever and exposed to the steam pressure in the stage from which seid pipe leads.

In witness whereof, I have hereunto my hand this third dey of August, 1909.

RCHARD H. RCE.

Images