US1651855A - Elastic-fluid turbine - Google Patents

Description

Dec. 6, 1927. v 1,651,855 v G. B. WARREN ELASTIC mm) TURBINE F1]. :1 June 24, 1924 TIPiI/Iill/ 7 v Fig.4.-

Ipvehtor: Flg- Glenn B.Wc1rre"n,

His Attorne Patented Dec, 6, 1927 I umrsn STAT/ES- PATENT owner...

.GLENN B. wannnn, or scfinnncrsnr;"nnw' onk, assrenon T GENERAL ELECTRIC 1 I comramr, A. conrona'rron or NEW roan.

' ELASTIC-FLUID rename.

The present invention relates to elastic fluid turbines and especially. to diaphragm following stage, wheels 9 and 11 being carpackings for, turbines of-the type wherein the casing or housing is divided into stages. 6 by nozzle diaphragms, although-as tojcer-' tain broader aspects, 1t is not necessarily In connection with the operation of elastic fluid turbines,it is known that when a 0 turbine is operating at full load, it runs more smoothly and .is less likely to vibratethan when running at light load. This is because a turbine when runningat full load is even- 1y heated and is 'subjectedto little temperature-and pressure changes; On the other, hand, when a turbine is running at light load or, is being started-up, it may be subjected to changes in temperature and pressure of considerable magnitude and at such times is much 'more likely to operate unevenly or to vibrate.

Now, in the operation of'elastic fluid turdesirablefthat the packings run bines, it is with as close a clearance as it is possible to maintain so as to redpce the leakage to a minimum and it follows from the foregoing that because of the greater smoothness of operation, closer packing clearance can be maintained when the turbine is operating a at full load than when it is-being started up or is operating at lighter loads, and the o ject of my present invention is to provide an improved packing which is automatically adjusted so as to vary the clearance in. accordance with the load on the turbine, the clearance being the closest when the turbine is operating under full load conditions.

For 'a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawing, Fig. I is a sectional view of a part of an elastic fluid turbine having a diaphragm packing embodying my invention; Figs. 2 and 3 are detail views on a larger scale, illustrating the operation of my invention; and Fig. 4 is a detail view ofia modification.

Referring to the drawing, 5 indicates the casing-of an elastic fluid turbine, which casing is divided into stages by nozzle diaphra s 6, the nozzles being indicated at 7. Nozz es 7 receive elastic fluid from buckets 1 ja noaa mea manna. Serial No. 722,120.

charge it'to buckets 10 on a Wheel 11 in the ried by as'haft 12.' Only one diaphragm and they adjacent turbine wheels are shown in the drawing, the illustration of only a portion of a turbine being necessary to an understanding of my invention.

The construction so far described is a known one and i to be taken as typical of any turbine structure to which-my invention may be applied.

Now, according to my invention as carried out in connection with diaphragm packing, I provide-on the shaft a packing element 13 comprising annular packing teeth 14:" and on the diaphragm a packing element 15 comprising annular packing teeth 16 which 00 operate with packing teeth 14. When a tur-.

bine is in operation, there is a drop in pressureacross the diaphragms which drop in pressure increases with the load and this pressure on the diaphragm causes them to deflect somewhat toward the low pressure end of the machine, the deflections being the 8 on a-wheel 9 ofa preceding stage and disgreatest when the turbine isoperating at full load. 7 In carrying out my invention, I take advantage of this fact and utilize the deflection of the diaphra s due to increase in the load for varyin t e clearance of the packings. To this en I arrange the packings so that when the diaphragm deflects toward the clearance in the packing will be decreased and I then so construct the packing that there is ample clearance at no load and so that the desired closer clearance will be established at full load due to the deflection of the diaphragm.

Referring to Figs. 1, 2 and'3, it will be seen that the desired result is obtained by tapering the packing elements, the packing elements on both the diaphragm and the ro tor being tapered or having conical packing surfaces in the present instance, and it will be clear that Wit-hthis arrangement when the diaphragm deflects toward the low pressure end of the machine, 1'. e., toward the right in the drawing, the clearance in the packing will be decreased. I This is well illustrated in the enlarged views in Figs. 2 and 3 wherein Fig. 2 illustrates the normal no the low pressure end of the. turbine,

load position of the packing elements, and Fig. 3 illustrates the position of the packing elements when the diaphragm is deflected under full load conditions of operation. I 5. The specific type of packing elements comprising the straight teeth 14 cooperating with the sloping teeth 16 are shown only by way of example and as being a desirable form of packing structure to use in carrying out my invention. They form no part of my present invention. Any suitable type of packing may be used.

In Figs. 1 to 3, the straight teeth are shown as being carried on the rotor and the sloping teeth as being carried by the diaphragm. However, I may use the reverse of this arrangement and such a reverse arangement is shown in Fig. 4 of the drawing wherein 17 indicates the dia- 80 phragm provided with the straight toothed packing element 18, and 19 indicates the rotor or shaft provided with the sloping toothed packing element 20. In this arrangement, the extent of the contact be-.

85 tween packing element 20 and shaft 19 is decreased by providing a groove 21 in the bore element 20. This serves to prevent rapid transfer of heat from the packing element 20 to the shaft, a thing which, as .is known, it is desirable to avoid. In accordance with the provisions of th patent statutes, I have described the principle of operation of my invention, together. with apparatus which I now consider to represent the best embodiments thereof, but I desire to have it understood that the ap-' paratus shown is only illustrative and that the invention may be carried out by other means. a

What I claim as new and desire to secure by Letters Patent of the United States, 1s:

The combination with an axialflow multistage elastic fluid turbine, of means for vary ing an interstage packing clearance therein in response to load on the turbine, said means comprising a diaphragm between two stages, which diaphragm is sufliciently flexible to deflect toward the low pressure end of the turbine increasingly as the pressure drop across it increases, a packing element carried by the diaphragm and arranged to move therewith axially when the latter is deflected, and a packing element with which said first-named packing element cooperates to provide the inter-stage packing clearance, said packing elements being annular in form, concentric, and tapered in the direction of the high pressure end of the turbine whereby the clearance between them is an 60 nular and tapers in the same direction.

In witness whereof, I have hereunto set my hand this 23rd day of June 1924.

y GLENN B. ARREN.

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