US911350A - Steam-packing for turbines. - Google Patents

Description

c. P. WETHERBEE.

STEAM PACKING FOB. TUBBINBS.

APPLICATION FILED JUNE 20, 1908.

Patented Feb. 2, 1909.

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C. P. WBTHBRBEE.

STEAM PACKING FOR TURBINES.

APPLICATION FILED mm; 20, 1909.

91 1,350. Patented Feb. 2, 1909.

L 6 BHBBTSSHEBT 2. 1(3) 7 U. P. WBTHERBEE.

STEAM PACKING FOE TURBINES.

APPLICATION FILED JUNE 20, 1903.

91 1,350, Patented Feb. 2, 1909.

G. P. WBTHERBBE.

STEAM PACKING ron TURBINBS.

APPLICATION FILED JUNE 20, 1908.

Patented Feb. 2, 1909.

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G. P. WBTHERBEE.

STEAM PACKING FOB TUBBINBS.

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91 1,350. Patented Feb. 2, 1909.

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bU lltneefies. 17111811102: W /f/ (2 UNITED STATES CHARLES P. WETHERBEE, OF BATH, MAINE.

STEAM-PACKING FOR TURBINES.

Application filed June 20,

To all whom 'it may concern:

Be it known that 1, CHARLES P. WETHER- BEE, of Bath, in the county of Sagadahoc and State of Maine, have invented certain new and useful Improvements in Steam- Packings for Turbines, of which the followingris a specification.

his invention relates to steam turbines, and consists of a system for sealing the shaft stuffing-boxes or glands with steam, and maintaining a constant pressure in the seal so as to revent steam V leakage outward from the high-pressure turbines and leakage of air into the low-pressure turbines.

In brief, it consists of connections between the stufling-boxes of the several membersof a turbine installation so that the steam leaking from the glands of the high-pressure turbine may seal the glands of the low-pressure turbine, together with outlet and inlet connections by whih the steam pressure in all the glands may be maintained at any desired point above that of the atmos here, and kept from rising above the esired point.

Of the accompanying drawin s,Figure 1 represents a plan view of a tur ine installation consisting of a high-pressure and two low-pressure turbines. Fig. 2 represents an elevation of the same. Fig. 3 is a diagrammatic representation, on an enlarged scale, of the installation shown in Fi 1. Fig. 4 represents an end elevation of t e engine as seen from the forward side. Fig. 5 represents an and elevation as seen from the 0 posite end thereof. Fig. 6 represents a ragmentary elevation of a somewhat different layout of turbine engine, showing also the -valvc for admitting and relieving steam in the gland connections. Fig. 7 represents a fragmentary sectional view of one end of a steam turbine, showing the shaft stufiingbox or gland. Fig. 8 represents an enlarged longitudinal section of the stufling-box or gland. Fig. 9 represents a cross-section of the same on line 9-9 of Fig. 7.

The same reference characters indicate the same parts in all the figures.

Referring to the drawin s, a re resents a high-pressure turbine, am 5 MR 0 represent two low-pressure turbines arranged as the same are laid out in an engine-room. The hi h-pressure turbine takes steam from the be: or and exhausts it into the two lowpressure turbines through pipes d and e.

Specification of Letters Patent.

1908. Serial No. 439.5001

' edges of each fin almost touchingl Patented Feb. 2, 1909.

through the conduits f and 9 into the condenser h.

The revolving shafts of the turbinespass of the cylindrical casings, these stuffingboxes being constructed as shown, in Figs. 7 and'9. Each is formed as a sleeve '0' surrounding a shaft 9', and containi v packing elements. These consist of annu ar sharp fins k and l set alternately into the interior of the sleeve and the exterior of the shaft, the

the opposite surface. Beyond the fins t e stuflingbox is formed with an annular pocket or chamber m, and between the latter and the end of the stuffing-box is a series of snap rings n set intoannular grooves in the cylinder and bearing against the internal surface of the sleeve. The overla ping fins form a labyrinthine stuffing-box throu h which the steam leaks slowly into the poo at m, which I call the leak-off pocket.

The pressure tending to move the steam through the stuffing box is that of the exhaust of the turbine. In the high-pressure turbine it may be varied from vacuum to a considerable amount above the atmos heric pressure, while in the low-pressure tur ines, it is always a vacuum almost as great as that in the condenser. There is thus a tendency for steam to leak out of the hi h-pressure turbine along the shaft to t e leak-off pocket, and an o posits tendency for any steam which may lie sup lied from an external source into the leal -ofl pocket of the low-pressure turbine to leak therefrom alon the shaft into the interior of the turbine, and thence to the condenser.

My. invention consists in connecting the leak-off pockets of the high and low-pressure turbines together so that the steam which is supplied to the former by leakage will pass to thelatter and seal the lowressure turbine glands so that air will not eak into the turbine. For making these connections, I provide a system of piping consisting of the main ipe o with who connect branches p q r s t eading to each of the several stuffingboxes. The connection with each leak-off pocket is made through a chamber u beneath the stufling-box from which passages 11 extend to the pocket. It will be readil seen that the pressure in the piping, which term the "gland edhalizer pipe, and in all the From the latter the steam is exhausted through stuffing boxes or glands in the ends so leak-off pockets, will be the same, for the I steam at high pressure in the pockets of the high-pressure turbine glands flows at once to the low-pressure glands and equalizes the pressure.

It is necessary to maintain the pressure in the gland pockets slightly above the atmosheric pressure, so that there may be no eakage of air into the lowressure turbines, but it should be only a slig 1t amount above the atmospheric pressure to minimize leakage beyond the snap rings 1 of the stuffingboxes and loss of steam. In ractice I maintain the pressure in the equalizer ipe at one or two pounds above the atmosp ere.

If there is not enough steam supplied by leakage from the high-pressure turbine to maintain this pressure, additional steam must be supplied from some other source, such as auxiliary exhaust, a higher pressure stage of a turbine, or even boiler steam, while, if, on the contrary, the flow from the high-pressure gland is greater than the leakage mto the low-pressure turbines, it is necessary to relieve the excess of pressure by exhausting some of the steam into the condenser or to some stage of the turbine where the pressure is less than that to be maintained in the gland pockets and equalizer 30 pipes.

The connections for admittin and exhausting the steam to and from t epipe are best shown in Fig. 6, Where w is a brano connection leading to the condenser conduit 35 and x is a supply pipe from some source where pressure is greater than that desired in the land ockets, and connected to the glam equa izer pipe. The latter is governed by a valve y, while the exhaust connection has a valve 2. These valves may be ordinary hand valves, sprin loaded valves, or reducing or pressure-regu ating valves, as

desired. When properly adjusted, they serve to maintain the steam at the desired pressure in all of the gland leak-off ockets, and by adjustment, the pressure in rill of the glands simultaneously may age 2 is connected to the equalizer pipe and coated at the handling platform.

I claim:-

1. In combination with a series of steam turbines, of pressure-equalizing connections between the stuiling boxes of the several turbines.

2. In a steam turbine installation, consisling of a series of turbines exhausting steam at dill'erent pressures, each having shalt stulling boxes or glands, a gland equalizer pipe connected to all the turbine stuiling boxes, in which steam is maintained at a pressure slightly above that of the atmosphere.

3. In a steam turbine installation, consisting of a series of turbines exhausting 65 steam aLdillerent pressures, each having a be varied. A

shaft stufiing box or gland, containing packing members and provided with a pocket or chamber beyond said packing members, a' gland equa izer pipe connected to the pockets or chambers of all of said stufling oxes to maintain a uniform pressure therein.

4. In a steam turbine installation, consisting of a series of tuibines exhausting steam at different pressures, each having shaft stuflmg boxes or glands, with packing elements in said stufling boxes, pipin connecting all of the stuffing boxes toget er at points outside of or beyond said packing elements, with provisions for maintaining steam pressure in said piping slightly above atmospheric pressure.

5. In a set of highand low-pressure turbines having shaft stufling boxes provided with I steam pockets, provisions for ermitting flow of steam between th 1 stu n box pockets of the several turbines to cqua ize the pressure therein and maintain ie same in all slightly above the atmospheric pressure.

6. In a set of highand low-pressure turbines having shaft stuffing boxes rovided with steam pockets, provisions or ermitting steam leaking into the stufiingox ocket of the high-pressure turbine to flow mto the stuffing box pocket of the lowpressure turbine to maintain the pressure in i the latter above the atmospheric pressure and prevent leakage of air into the low-pressure turbine.

7. In a set of highand low-pressure turbines having shaft stufling boxes provided with steam pockets, provisions for ermitting steam leaking into the stufling ox ocket of the high-pressure turbine to flow 105 mto the stufling-box pocket of the loaressure turbine to maintain the pressure in the latter above the atmospheric pressure, together with provisions for relieving excess pressure and for making up deficiencies in the supply of steam.

8. 1n the combination of highpressure and lovwpmssure turbines having shaft st-ulling-boxes provided with steam pockets, piping connecting the ockets of the diflerent turbines ti gether so t iat steam leaking into the pocket of the higlnpressure turbine may flow into the pocket of the low-pressure turbine and seal the gland thereof.

9. The combination of highressure and low-pressure turbines having s ialt stufling boxes provided with steam pockets, piping connecting the pockets of the dill'erent turbines together so that steam leaking into the ocket of the high-pressure turbine may flow into the ocket of the low-pressure turbine andseal the land thereof, and an outlet from said piping For escape of excess of steam to permit the pressure in the pockets to be maintained at a certain maximum.

10. The combination of highressure and low-pressure turbines having shaft stuffing boxes provided with steam pockets, piping connecting the pockets of the different turbines together so that steam leaking into the pocket of the high-pressure turbine may flow mto. the pocket of the low-pressure turbine and seal the gland thereof, and a connection with said iping from a source of steam supply, b w 'ch steam, in addition to that fornishe from the high-pressure poc'ket, may be supplied to the low-pressure pocket to maintam a sealing pressure therein above the atmospheric pressure.

11. In combination with a set of turbines 15 having shaft stuffing boxes, an auxiliary source of steam supply, a single valve controlling admission of steam from said source and connections for leading steam from sai valve to all the stuffing boxes to provide a 20 steam seal at a pressure regulated by the sin le valve.

n testimony whereof'I have affixed my signature, in resence of two witnesses.

CHXRLES P. WETHERBEE. Witnesses:

HUBERT H. MCCARTY, VIM, M. ADAMS.

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