From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Notes on the St. Jacques patent silencer, detailing its essential characteristics and principles of operation.
| Identifier | ExFiles\Box 152\3\ scan0159 | |
| Date | 1st April 1934 guessed | |
| NOTES ON THE ST.{Capt. P. R. Strong} JACQUES PATENT SILENCER. The essential characteristics of the St.{Capt. P. R. Strong} Jacques Patent Silencer are the following :- 1. The ta-ngential admission of the ex-haust gases into the cylinder. 2. The spiral bladed diaphragm. The tangential admission of the gases avoids the back pressure caused in all devices in which the gases are admitted through the centre of the cylinder and strike against baffle-plates which deflect the gases. It further imparts to the gases a long spiral path in a relatively small space. The centrifugal forces resulting from this tangential admission project the gases against the sides of the cylinder to which they transmit a large p-roportion of their heat, which is thus dispersed direct into the air. The spiral bladed diaphragm has for its object in the first place, to redirect the gases into the spiral path, since that would naturally have the tendency to become longer. It further has the object of dividing the volume of gas into a multitude of small streams which come into contact with a large number of metallic plates. These in turn transmit the heat to the outer casing. This part of the silencer therefore forms a kind of heat exchange, with the effect of considerably reducing the volume of the gases. The gases come out of the silencer in a spiral stream, thus producing the maximum displacement of air to which it imparts its heat. In actual practice, this silencer has given results which are better in actual silencing, with the additional advantage that it produces no more back-pres-sure than direct exhaust into the air. The only energy consumed is that actually caused by the friction of the gases against the sides of the cylinder, and by the slight progressive compression which is partially com-pensated by the gradual acceleration of the gases. | ||