US1949683A - Feed water regulator - Google Patents

Description

March 6, 1934. H. s. FRASER FEED WATER REGULATOR Filed Dec. 13, 1930 HOWARD 5- FPASEB Patented Mar. 6, 1934 UNITED STATES PATENT 'QFFICE FEED WATER REGULATOR Howard S. Fraser, New York, N. Y., assignor to The Swartwout Company, Cleveland, Ohio, a.

corporation of Ohio This invention relates to the control and regulation of feeding water to boilers, and particularly to marine boilers, wherein the boilers roll and pitch and otherwise change their angular position during the course of their operation.

It will be appreciated that in marine boilers the rolling and pitching of the ship necessarily causes the water in the boiler to swing from side to side and from end to end of the upper drum and it will also be appreciated that, as a result of the rolling and pitching of the ship, the surface of the water in the upper drum will obtain a wave-like motion, swinging well above the desired water level at one end or at one side of the drum and swinging well below the desired water level at the other end or side of the drum. The surface of the water in the top drum will deviate from a plane surface depending upon the extent of the motion of the ship and I conceive that when the motion is great the water will distinctly pile up at one end or side of the boiler leaving little or no water in the other end or side of the boiler.

It is therefore among the objects of my invention to control the flow of feed water in a continuous and even manner substantially commensurate with the load on the boiler and in a manner which will maintain a quantity of water in the boiler such as would be maintained along a given water level if the boiler were stationary. A further and more specific object is to accomplish the major object with means such as have been found highly satisfactory for a long period of years for maintaining a substantially constant water level in stationary boilers.

Other objects will appear from the following description of a preferred form of my invention, reference being had to the accompanying drawing. The essential characteristics are summarized in the claims.

In the drawing, Fig. 1 is a partial side elevation of a boiler showing particularly the top drum; Fig. 2 is an end elevation of the left end of the drum of Fig. 1; Fig. 3 is an end elevation of the right end of the drum shown in Fig. 1; Fig. 4 is a top plan view of the drum of Fig. 1; and Fig. 5 is an end elevation of a boiler illustrating a modified form of my invention.

Referring to the drawing, I illustrate more or less diagrammatically a boiler having a drum D in which, were the boiler stationary, it would be desired to maintain the water level about along the line L--L. Water is fed to the boiler through the feed water pipe 1 and steam is taken from the boiler through the steam pipe 2. A feed water valve 3 is positioned in the feed water line and is preferably of the pressure actuated type similar, at least in principle, to that shown in the well known Copley Patent No. 1,193,125. According to the general practice of Copley the feed water valve is pressure actuated and receives its actuating pressure through a conduit 4 which, as shown in Fig. 2, leads to a pressure generator 5 mounted at the water level and mounted on a conduit 6 which spans the water level and communicates with the steam and water spaces of the drum D. The operation of the generator and the valve 3 is disclosed in the Copley patent; let it suffice to say for this description, that the generator comprises a tubular body portion sur-' rounding the conduit 6 and containing an expansive fluid such as alcohol, water or mercury depending upon the pressure and temperature of the steam in the drum D. As the water level in the conduit 6 varies, greater or lesser portions of the generator are subjected to the heat of the steam in the conduit or chilled by the presence of water with the result that varying pressures are created depending upon the level of water in the conduit 6.

According ot the principle of the Copley patent, when the water level in the conduit 6 is low, relatively high pressures are generated which open the feed water valve 3, and, as the water level in the conduit 6 rises due to the addition of water to the boiler, the pressure is reduced thereby gradually closing the feed water valve. In this way a continuous feed is maintained which tends to maintain a constant level of water in the boiler drum.

The Copley invention has been successfully used for years on stationary boilers. In marine practice, however, it will be seen that the generator 5 will create pressures responsive to the water level in the conduit 6, which water level may or may not reflect the true water level in the drum if the ship is pitching and rolling. In other words, if we regard the generator 5 as being attached to the after end of the boiler drum, it will be seen that, when the bow of the ship is low, the water will rush to the forward end of the boiler with the result that the water level in conduit 6 will fall and the feed water valve will be opened more than is necessary to maintain the desired quantity of water in the boiler. This will cause an excess of water to be fed when the bow of the ship is low and, conversely, a dearth of water will be fed when the bow of the ship is high.

Furthermore, the use of a single generator as prescribed by Copley on a marine installation will give an intermittent feed with the resultant well known lack of economy and danger of flooding the boiler and passing water over into the turbine.

It will also be appreciated that a similar problem is present when the ship rolls and if the generator is disposed or (connected strictly to the starboard amidship) the center line of the boiler drum, the surging of water from side to side will cause the mean Water level in the midle of the drum to be less than. that which would result from the proper mass of water in the drum where the boiler is stationary. If the generator is positioned as illustrated in Fig. 2 on the port side of the drum, then the rolling of the ship will alternately flood the conduit 6 to chfll the generator and empty the conduit 6 to heat the generator. This action will give a resultant intermittent opening and closing of the feed water valve and a consequent intermittent feed.

To overcome these dir uculties, I provide a second generator '7 on the opposite end of the drum from generator 5 and mounted on the starboard side of the drum, Whereas the generator 5 is mounted at the port side of the drum. The generator '7 is preferably in all respects similar to the generator 5 and is connected to the feed Water valve by a conduit 8 which joins the conduit 4 at the point 9. Preferably the combined capacity of the generators 5 and '7 is substantially that of a single generator adapted to operate a stationary boiler of like size and rating. The efficacy of using two generators lies in the result that between the two generators a substantially constant pressure will be maintained for any given water level whether the ship is steady or whether it is pitching and or rolling. Thus when the ship is steady, both generators will be heated substantially like amounts and will exert between them a common pressure through the conduits 4 and 8 to hold the feed water valve at the desired open position to maintain a water level substantially along the line L-L.

When the ship begins to roll or pitch it is desired to maintain the same quantity of water in the boiler, albeit the water in the drum D is surging from end to end and side to side. By my novel disposition of generators, it will be seen that when the water surges forward in the drum D, the generator 7 will be chilled by reason of the high water in the conduit 10 upon which the generator 7 is mounted, whilst the generator 5 will be heated to a greater degree by reason of the low water in the conduit 6. The resultant effect, however, of pressure in the conduits 4, 8 and on the feed water Will be the maintenance of substantially constant pressure which will hold the feed water valve in a relatively fixed position. In other words, by the disposition of the generators respectively fore and aft and starboard and port of the drum D, a substantially constant pressure will be maintained on the feed water valve for a given load on the boiler, which will maintain a substantially constant and continuous feed which, Were the ship stationary, would maintain the water level along the line LL.

In Fig. 5 of the drawing, I have illustrated a modified. form or" my invention in which a pair of generators 11 and 12 are mounted on opposite sides of one end of a boiler drum. The conduits 13 and 14 lead from these generators to the feed valve 15 and the action of the valve is controlled in the same general manner as explained above in reference to valve 3. The arrangement illustrated in Fig. 5 is advantageous on some ships where one end of the boiler drum is inaccessible. However, the installation shown in Figs. 1 to 4 inclusive is preferable as it takes care or a greater variety of conditions of pitch and roll of the ship.

The generators are preferably hooked up to the boiler through their connecting conduits so that they may be adjusted vertically a certain amount. The Copley Patent No. 1,193,125 illustrates an adjustable connection of this type. Such adjustability is desirable to take care of the particular installation problems of each boiler. For example, the action of generators mounted on a boiler located on the longitudinal center line of the ship will be slightly difierent from that of generators mounted on boilers near the sides of the ship. The rolling and pitching of the vessel will cause a surging action of the Water in the boiler drum having characteristics which may vary with the position of the drum in the ship. For this reason it is desirable to have the generators adjustable so that they may be conveniently set to give the desired feed water regulation regardless of the position of the boiler in the ship.

It will be appreciated that the size of the generators and the exact location of the generators will depend upon the operating conditions and characteristics of the boiler to which they are attached.

While the foregoing is a description of a preferred form of my invention, I do not care to be specifically limited thereto. No more do I wish to be limited particularly to fluid presstue generators and pressure actuated feed valves because those skilled in the art will appreciate that other well known types of feed water regulators and feed water valves might be used according to the precepts of my invention to give comparable results, and while various modifications and changes may occur to those skilled in the art, all within the major precepts of my invention, I do not wish to be limited to this specific disclosure or in any other manner other than by the claims appended hereto.

I claim:

1. The method of controlling the flow of feed water to a boiler comprising varying the flow through a single feed water valve in accordance with variations in the average water level at a 5 plurality of points starboard and port, fore and aft, of the boiler.

2. In combination, a marine boiler having a drum, and being adapted to pitch and roll at intervals during operation, a pressure actuated feed water valve for controlling the flow of water to said drum, a pair of pressure generators, one of said generators being mounted on one end of said drum and on one side of the center thereof and the other of said generators being mounted on the opposite end of the drum and on the opposite side of the center thereof, and pressure conducting connections between said generators to said valve whereby a substantially constant pressure is exerted on said valve during pitching and rolling of the ship.

3. In a feed water regulating system for a marine boiler adapted to pitch and/or roll, the combination of a pressure actuable feed water valve, pressure generators for actuating said valve and associated with said boiler at opposite ends and on opposite sides of the longitudinal center line in the plane of normal quiescent water level thereof and fluid conducting means leadin from said generators to said valve whereby a 15G substantially constant pressure is exerted on said valve during pitching or rolling of the ship even when the pressure of the individual generators is rising and falling.

4. In combination, a marine boiler adapted to roll and pitch, a single feed water valve means therefor and feed water regulator means placed in the plane of normal quiescent Water level and responsive to variations in boiler water level for varying the opening of said single valve means, said regulator means comprising separate interconnected elements connected to said boiler at points spaced from each other fore and aft and port and starboard respectively, the total capacity of said separate regulator elements being substantially the same as that of a single element adapted to regulate the flow of feed water to a stationary boiler of like size and rating.

5. In combination, a marine boiler adapted to pitch and to roll, a single pressure actuated valve for feeding water to said boiler, and a plurality of pressure generators mounted on said boiler at points spaced from each other fore and aft and port and starboard and connected to said feed water valve, the total capacity of said pressure generators being substantially the same as that of a single generator adapted to control the feed Water valve of a stationary boiler of like size and rating, whereby a substantially constant pressure is exerted on said pressure actuated valve during periods of pitching and rolling of said boiler.

HOWARD S. FRASER.

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