|Appendix A2 The
The Kylpor differentiates from the Lempor by the fact that it makes use of the Kylala four lobe mixing device and therefore resembling the Kylchap of the type 1K/1T. Both types are thermodynamically equivalent except that the Kylpor has greater friction in the mixing chamber, this leading to the written preferences for the Lempor in recent designs. Nevertheless, the design is worthy of application in the case of a double concentric tuyère. In this design, the inner smaller tuyère is connected to the cylinder during the release phase, while both- the inner and the larger- gives an extra area during the exhaust phase. This larger area determines a very low back pressure on the exhaust line and the explanation is to be sought in the fact that actually most of the work is done by the puffing steam through a very small tuyère and thereby extracting a good deal of work of the incomplete expansion toe of the indicator diagram.
It can be shown that the upper mixing chamber of the Kylpor must be cylindrical while the bottom gas section and the tuyère must be equal to that of the tip of the Kylala petticoat. This is to comply with the requirement F1=Fb.
Unlike former designs, there is no interest in having a uniform distribution of velocities at the Kylala exit and therefore this element should be as short as possible to reduce the unavoidable friction.