Патент USA US2111878код для вставки
March .22, 1938. H. VAN TONGEREN 12,111,873 ‘MEANS FOR DRAINING MOISTURE FROM STEAM IN STEAM TURBINES ' Filed June 26, 1956 F163 \ FIE-3.4 FIGS Patented Mar. 22, 1938 2,111,873 UNITED STATES PATEEV‘QET 'QFFIQEA 2,111,878 MEANS FOR DRAINING MOISTURE FRQM - STEAM IN STEAM TURBINES Hermannus van Tongeren, Heemstede, Netherlands 7 Application June 26, 1936, Serial No. 87,566 In the Netherlands July 2, 1935 3 Claims. (Cl. 253-76) This invention relates to means for draining moisture from steam in steam turbines. It is well known that in steam turbines, and the water droplets are radially thrown off. Sur rounding said drip rim, the inner face of easing especially in the low pressure stages thereof, part chined therein. As shown, the depth of said groove is greatest in the radial plane passing 5 of the steam is condensed and that the water of condensation thus formed has a deteriorating action on the blades. The principal object of my invention is an improved construction whereby the water droplets, which are thrown by cen 10 trifugal force from the rotor or rotors, are col lected--and thereafter discharged from the oas— ing-in such a manner that they cannot possibly return into the blading. ‘ With this object in view, I suggest to provide a circumferential groovein the inner wall of the casing, said groove being so disposed relative to the corresponding rotor that the droplets thrown radially outwards vfrom the rotor can reach the body of water already present in the groove with out contacting with any stationary part of the turbine. Since the body of water in the groove, owing to the impacts of the droplets thrown thereinto, has a circumferential speed not essen tially smaller than that of the droplets, the latter N2 in will be caught thereby without considerable re bounding. It will easily be understood that such a gyrating mass of water surrounding the rotor is much better adapted to catch and hold the droplets than are stationary solid walls. In order that- my invention may be more fully 2 has a circumferential collecting groove ‘I ma through the drip rim, i. e. on the outlet side of the moving blades, and gradually decreases to wards the radial plane passing through the inlet side of said blades. Through a small portion of the circumference, the sloping side wall of the groove 1 is recessed so as to form a sill II] located at a somewhat smaller distance from the turbine axis than the bottom of the groove. Secured to said sill as by screws 8a is a nozzle 8 ?tted at the inner end of a passage 9 provided in the wall 15 of the casing 2 and serving to discharge water collecting in the groove. When the turbine is in operation, the groove ‘I will after a certain period of time be ?lled with a gyrating, annular body of water, the more or 20 less cylindrical inner surface of which will be substantially flush with the sill Ill. Any water ?owing over said sill ‘will be forced by its kinetic energy into the nozzle 8 and thus be discharged through the passage 9. 25 Figs. 3, 4 and 5 clearly show that any droplet thrown radially off the drip rim 6 will reach the level of the gyrating body of water in groove 1 and thus be caught and held by said water, with“ out coming into contact with the radial right understood by those skilled in the art, I shall hand side wall of said groove or with any other now proceed to describe the same in further de stationary part of the casing. tail with reference to the annexed drawing, in which: It is not necessary to provide every rotor ele ment traversed by more or less wet steam with a draining device as described. For instance, a Fig. 1 is part of an axial section of an axial flow turbine, group of rotor elements or blade wheels, only the . Fig. 2 shows part of a cross-sectional view of ‘ said turbine, along the line II--II in Fig. 1, last wheel on the outlet side of such group to» Figs. 3, 4 and 5 illustrate parts of axial sections 40 along the lines III--I1'I, IV—IV and V—V, re spectively, in Fig. 2, such wheel may be provided with a draining device. Figs. 6-10 of the drawing illustrate another embodiment of my invention, wherein the butt strap II is provided with two drip rims I2 and Fig. 6 shows a modi?cation as part of an axial section of another axial flow turbine, Fig. 7 is part of a cross-sectional view of said turbine, along the line VII—VII in Fig. 6, and Figs. 8, 9 and 10 are parts of axial sections along the lines VIII—VIII, IX-~IX and X--X, respectively, in Fig. 7. ' ‘ In‘Figs. 1-5, a rotary blade wheel is desig nated by I, the turbine casing by 2. The nu merals 3 and 4 indicate normally shaped ?xed guide blade rims on either side of wheel I. The butt strap or sealing ring 5 of the moving blades is provided, on the right hand side, i. e. on the outlet side, with a drip rim or edge 6, from which gether with the part of the casing surrounding I3 on the inlet and on the outlet side, respec tively. Said drip rims are surrounded by water collecting grooves I4 and I5, respectively, ma chined in the turbine casing 2. Also in this case the depth of each groove is greatest in the radial plane of the corresponding drip rim. The grooves are separated from one another by an annular ridge I6, which through a small portion of its length is recessed to form a sill II, to which the nozzle 8 of the discharge passage 9 is secured by screws 8a. Secured to the inner face of the ridge I6 is a 55 2 2,111,878 flat ring l8, the side edges of which are suitably spaced from the opposite radial walls of the grooves 14 and I5, respectively, so that any drop lets thrown from the drip rims I2, I3 can freely pass through the narrow slots thus formed with out coming into contact with said walls. The strap l8 acts as a shield or baf?e having for its effect greatly to reduce the circumferen tial speed of the steam carried along by the butt strap I I. Owing thereto, the levels of the bodies of water in the grooves I4, l5 are not seriously disturbed by wave motion. What I claim is:— 1. In a steam turbine, a casing, a rotor ele 15 ment provided with a radially directed drip rim, a circumferential water-collecting groove in the inner wall of the casing situated in radial align ment of said drip rim and with its bottom spaced from said rim and a water-discharging conduit 20 opening into said groove substantially level with said drip rim, the groove being so disposed and formed as to permit water droplets thrown by centrifugal force from said drip‘ rim to collect in said groove thus providing an annular body of water and to prevent said droplets from being thrown into direct contact with any stationary solid Wall. 2. In a steam turbine, a casing, a rotor ele ment provided with a radially directed drip rim, ment of said drip rim and with its bottom spaced from said rim and a water-discharging conduit opening into said groove substantially level with said drip rim, the groove being so disposed and formed as to permit Water droplets thrown by centrifugal force from said drip rim to collect in said groove thus providing an annular body of Water and to prevent said droplets from being thrown into direct contact with any stationary solid wall, and an annular ba?le secured to the 10 casing partly closing said groove leaving only a narrow circumferential slot in the radial plane of said drip rim. 3. In a steam turbine, a casing, a rotor ele ment provided with a drip rim at its inlet and 15 outlet sides, a circumferential water-collecting groove in the inner wall of the casing opposite the inlet and outlet sides of said rotor element and in radial alignment with the respective drip rims, a circumferential ridge intermediate of said 20 grooves, a recess in said ridge forming a sill and a Water-discharging conduit opening in said sill substantially level with the drip rims, the grooves being so dispose-d and formed as to permit water droplets thrown by centrifugal force from the respective rims to collect in the respective grooves thus providing annular bodies of water in the bottoms of the grooves, said droplets not coming in direct contact with any stationary solid wall. a circumferential water-collecting groove in the inner wall of the casing situated in radial align HERMANNUS VAN TONGEREN.