Патент USA US2404995код для вставки
Patented July 30, 1946 2,404,995 UNITED STATES PATENT GFFICE 2,404,995 GAS BLAST CIRCUIT BREAKER Hans Thommen and Gottfried Brühlmann, Baden, Switzerland, assignors to Aktiengesell ‘ schaft Brown, Boveri & Cie, Baden, Switzerland, a joint-stock company Application February 18, 1944, Serial No. 522,934 In Switzerland January 20, 1943 4 Claims. 1 (Cl. 13S-39) Z During the operation of gas-blast circuit break indicated by the arrows. These flow guides can for instance consist of concentric cylinders that may be and preferably are located, as shown in ers it has been found that in the bends of the pressure gas piping the velocity of flow on the discharge side of the bends is very unevenly dis the drawing, in the element adjoining the pipe tributed. Since the rupturing arc is, however, 5 bend, that is into the switch chamber or an ad certain to avoid those places where there is a joining pipe section. maximum velocity of gas ilow, only those places Instead of providing a barrel-shaped bulge in where the gas ñow is weakest can really be effec the pipe bend it is also possible to achieve the tive for the extinction of the arc. This is there same effect in a standard pipe bend having a fore a disadvantage because it results in the rup circular cross-section at the inlet end and an annular cross-section at the outlet end for the passage of the pressure gas, by arranging a series of tapered ribs ,? inside the pipe which extend turing capacity of the gas-blast circuit breaker being considerably reduced. The present invention therefore concerns a pipe bend for the pressure gas piping of gas blast circuit breakers, where the aforementioned disadvantage is avoided according to the inven tion by providing means which so influence the ilow oi pressure gas in the pipe bends that the velocity of iiow on the discharge side of the bends along the axis of curvature, these ribs extending from the cylindrical surface of the hollow core a’ that imparts the annular cross-section to the discharge end of the pipe bend. These ribs can be located on a horn g which extends along the axis of curvature of the pipe bend. We claim: 20 1. A pipe bend for use in pressure gas piping, is distributed approximately uniformly over the whole cross-section of the pipe. In the accompanying drawing, Figs. 1, 2 and 3 are fragmentary views, in longitudinal central section, of portions of gas-blast circuit breakers including pipe bends that constitute embodiments 25 said pipe bend comprising a hollow body having circular cross-section c at the inlet end and an let opening. a circular inlet opening and an annular outlet opening in end planes at a substantial angle to each other, the inner wall of said annular outlet opening being formed by a core located within said hollow body at its outlet end, and means of the invention. The pipe bend a which serves either to connect together lengths of pressure gas piping or to join between said inlet and outlet end planes for ie latter to the switch chamber b of a gas-blast effecting a substantially uniform velocity of gas circuit breaker not shown in the drawing, has a 30 flow through diiîerent parts of said annular out annular cross-section d at the discharge end for the passage of the pressure gas, the planes of the inlet and the outlet ends being at a substan tial angle to each other, for example 90° as shown in the drawing. In Fig. 1 the outer curved wall of the pipe bend a has a barrel-shaped bulge which is eccentric with reference to the axis of curvature, i. e., the outer portion of the Wall is 2. A pipe bend as recited in claim 1, wherein said means comprises tapered ribs extending along the axis of curvature of the pipe bend from said core towards the inlet end of the pipe bend. 3. A pipe bend as recited in claim 1, in com bination with flow guides located in the annular outlet of said pipe bend for directing the gas paths parallel to the axis of the annular formed by extending the cylindrical outer walls 40 along outlet opening of the pipe bend. of the inlet and outlet ends of the pipe bend into 4. A pipe bend as recited in claim 1, in com merging Contact eccentrically of the axis of bination with a conduit section connected to curvature. By widening the pipe bends in this the outlet end of said pipe bend, and ñow guides manner it is possible to obtain an approximately located in said conduit section for directing the uniform distribution of the ñow velocity over 4 CR gas along paths parallel to the axis of the annular the annular cross-section at the discharge end. outlet opening of the pipe bend. This favourable effect can be still further in creased by means of ñow guides e which are HANS THOMMEN. located beyond the change of ñow direction, as GOTTFRIED BRÜHLMANN.