Maxims and Instructions for the Boiler Room / Useful to Engineers, Firemen & Mechanics; Relating to Steam Generators, Pumps, Appliances, Steam Heating, Practical Plumbing, etc.

by N. Hawkins

STEAM SEPARATOR.

This appliance, which is also called an interceptor or catch water, is generally a T shaped pipe.

Fig. 90.

This, although not a boiler fixture or fitting, is intimately connected with them: it is an appliance fast coming into use both for land and marine engines, to guard against the danger to steam engine cylinders arising from “the priming” of the boilers when the steam is used at a high pressure with high speed of the piston.

The separator is usually placed in the engine room, so as to be well in sight. The steam is led down the pipe round a diaphragm plate and then up again to the engine steam pipe. By this means any priming or particles of water that may be brought from the boiler with the steam will fall to the bottom of the interceptor or catch water, from whence it can be blown out, according to the arrangement of the pipes, by opening the drain cock fixed on the bottom. It has a water gauge fixed on the lower end, so as to show whether water is accumulating; and the engineers attention is required to see that this water is from time to time blown off.

In the illustration, [Fig. 90], is shown the simplest form in which the device can be made. The arrows exhibit the direction in which the steam travels, the aperture whence the water is to be blown out and the place for attachment of a water column. In practical construction the separator should have a diameter twice that of the steam pipe and be 2¹⁄₂ to 3 diameters long. It is often made with a round top and flat bottom and sometimes with both ends hemispherical. The division plate should extend half the diameter of the steam pipe below the level of the bottom of the steam pipe.

In [Fig. 91] is shown an improved form of a steam separator which consists of a shell or casing in which there is firmly secured a double-ended cone. On this cone there are cast a number of wings, extending spirally along its exterior. On entering the separator the steam is spread and thrown outward by the cone and given a centrifugal motion by the spiral wings. These wings are constructed with a curved surface.

It will be noticed that the steam on entering the separator is immediately expanded from a solid body into an annular space of equal volume to the steam pipe, whereby its particles are removed from the centre and thus receive a greater amount of centrifugal motion. The entrained water or grease, etc., is thus precipitated against, and flows along the shell of the separator, and is collected in a well of ample proportions at base of separator, where it is entirely isolated from the flow of dry steam.

Fig. 91.