FEED-WATER FILTER.

FEED-WATER FILTER.

The illustrations on this page show an apparatus for removing oil from feed-water, introduced into this country by the Ross Valve company, of Troy, N. Y. Some years ago Railton & Campbell, an English firm, brought it into notice on the other side of the Atlantic, and were able to secure its adoption on board many ocean steamers, especially those of the White Star and North German Lloyd lines, where it forms a by no means inconsiderable or unessential part of a surface-condensing engine plant, where fresh feed-water is not easily attainable. By it can be removed from the water of condensation, so as to render it available for being used again asfeed-water, the lubricating oil which the exhaust stream has carried with it out of the cylinders This oil, being fed to the cylinders without intermission, keeps accumulating little by little in the feed-water, and, by entering the boiler and spreading over the heating surface in a thin film, prevents the water from adhering to it, and thus causes some plate or tube to become overheated, even to crack. If there is mud in the boiler, or if scale has formed, it combines with the oil —the result being a thick paste—whereby the danger of the plates or tubes overheating or cracking is much increased.

The apparatus consists essentially of a chamber, in which is a bag of Turkish toweling, compactly folded in such a way as to secure a large filtering area in a small space. By drawing the bag over the bronze skeleton on the left of the prospective view (Fig 1) —showing the filter cage removed —and further drawing it down between each of the sections by strings wound round it,a series of deepcircular corrugations, forming the surface of the bag, will result, and, according to what is required, the filtering surface will thus exceed the area of the feed-water pipe 250 or 1000 times. While the water continues to pass through the threads of the toweling, these threads keep back the oil. until they are thoroughly saturated with it. The sectional view appended to this notice shows how the water passes through the bag and the metal skeleton from its outer side to the interior of the latter, and thence to the outflow pipe. The resistance to the passage of the water is increased through the oil gradually clogging up the filtering material. The difference in the two pressure-gauges shows this resistance. One of these gauges is located on the inlet side of the filter; the other, on thp outlet On this difference reaching two or three pounds the square inch, reversing the direction of thecurrent and letting the wash water run to waste will cleanse the filter; or that can be done equally well by exchanging the filter bag for a fresh one, which should be always ready on hand. The long handle seen in fig. 1 is used to open the head of the filter chamber, to change the bags, and to remove the skeleton and bag—all of which may be done in less than five minutes. To wash the filter by reversing the current of water, the valves shown in fig. 2, are operated as follows : First, screw down and close the inlet valve, A; then close B, and open the drain-cock. By slightly opening A, a current of water is created, which washes the Biter externally. By closing A and opening B, the water passes from the boiler through the filter bag from the inside. Thus, as will be seen from fig. 2, the valve A does double duty—that of a stop-valve aud that of a by-pass valve.