Utility is a Latin word meaning the same as the Saxon word usefulness, hence a utility is something to be used to advantage. An attachment is that by which one thing is connected to another; some adjunct attached to a machine or instrument to enable it to do a special work; these are too numerous to be described in this work; moreover their number is being so constantly added to that it would be vain to make the attempt. A few examples only follow. The Receiver is one of the most important and useful parts or connections of a steam pump. This apparatus, frequently called “Pump and Governor,” and illustrated in Figs. 589, 590 and 591, is designed to automatically drain heating systems and machines or appliances used in manufacturing which depend upon a free circulation of steam for their efficiency. It furthermore is arranged to automatically pump the water of condensation drained from such systems back to the boilers without loss of heat. By this operation it serves a double purpose: first to automatically relieve the system of the water of condensation constantly collecting therein, thus insuring a free and unobstructed circulation, and, incidentally, preventing snapping and hammering in the piping, which in many cases is due to entrained water; and second, to automatically deliver this water, which in many cases is at the boiling point, directly to the boilers without the intervention of tanks or other devices commonly used. Not only does it relieve the system of a troublesome factor, but it introduces a supply of feed water to the boiler at a temperature impossible otherwise without the use of a special water heater. The economy resulting from its use is unquestionable, and the satisfactory and increasing use of this machine leaves no doubt as to its efficiency. As will be seen by the illustrations, the apparatus consists of a cylinder or oval closed receiver, which, together with the pump, is mounted upon and secured to a substantial base, making the whole machine compact and self-contained. The automatic action of the pump and its speed are controlled by a float in the receiver operating directly, without the use of intervening levers, cranks and stuffing boxes, to open or close a governor valve in the steam supply pipe to the pump, thus making the action of the pump conditional upon the rise and fall of the float in the receiver. Fig. 589. In each of the three receivers shown there is a ball float which appears through the side of the receiver, Fig. 590; these depend upon the principle of specific gravity for their operation. The lever fastened to the ball float operates the throttle valve of the pump; as the vessel fills with water the float rises opens the throttle valve, and starts the pump. In Fig. 589 is shown the Deane automatic duplex steam pump and receiver fitted with valves for hot water; it is also provided with three separate inlets for convenience in connecting the returns. In placing the apparatus, it is only necessary to so locate it that all returns will drain naturally towards receiver and that there are no pockets in the piping. When it is desired to use the automatic receiver as the sole means of feeding the boilers, it will be necessary to introduce a small supply of water from some outside source to equalize the loss which occurs. It is desirable that this water should flow into receiver rather than into discharge pipe. Fig. 590. Fig. 591. Fig. 590 shows a Mason steam pump with receiver attached. This pump is described elsewhere at length. Fig. 591 represents the Worthington duplex steam pump with its specially designed receiver. The ball cock is a faucet which is opened or closed by means of a ball floating on the surface of the water as it rises and falls in the vessel. In the illustration, Fig. 592, to be seen below the principle of its operation may be discerned. The fall of water in the tank lowers the float and opens the valve (which has in this case a rubber seat) and a rise of water in the tank closes the valve, hence this ball float controls and maintains a constant water level in the tank. Fig. 592. The float is a hollow ball of copper attached to one end of a lever while the other end is pivoted by a pin through it and the side of the shell of the valve. The valve itself is held by a screw to the lever and resembles very much an inverted lever safety valve. This principle of construction and operation is applied to many devices among which is that described on page 318 relating to pump receivers. The apparatus constitutes an automatic arrangement for keeping the water at a certain height. It is useful in cisterns, water backs, boilers, etc., where the supply is constant, the demand intermittent. TANKS AND CISTERNS.Fig. 593. A tank is an artificial receptacle for liquids, thus: a tank engine is one which carries the water and fuel it requires, thereby dispensing with a tender; tank-iron or steel is common plate used in building tanks. Steel is cheaper than sheet-iron. A cistern is primarily a natural reservoir—a hollow place containing water; more commonly an underground reservoir or tank. Closed pressure tanks are usually cylindrical shells similar to a horizontal steam boiler, having bumped or rounded heads to save bracing. Closed pressure tanks are used extensively in connection with hydraulic elevators; the requisite pressure for these was formerly derived from an open tank installed upon A closed pressure tank is shown in Fig. 596 in use with a hydraulic elevator. A reservoir is a place where water is collected and kept for use when wanted, so as to supply a fountain, a canal or a city by means of aqueducts or to drive a mill-wheel or the like. Fig. 594. A receiving reservoir is a principal reservoir into which an aqueduct or rising main, delivers water and from which a distributing reservoir draws its supply. A graduated tank is one fitted with water gauges and indicating marks, at different heights, between which, the capacity of the tank is shown. A ship’s ballast tank is the compartment for water to be pumped in and out for the purpose of insuring the proper stability of the vessel, to avoid capsizing and to secure the greatest effectiveness of the propelling power. Fig. 595. A vat is a cistern or tub, especially one used for holding liquors in an immature state, as chemical preparations and tanning liquor for leather. Fig. 594. A tub is an open wooden vessel formed with staves, bottom and hoops; a kind of short cask, half barrel or firkin, usually with but one head. Fig. 595. A gallon (U.S.) is equal to 231 cubic inches or 0.13368 cubic feet and weighs 81/3 lbs. nearly, (i.e. 8.3356). This is almost exactly equivalent to a cylinder 7 inches in diameter and 6 inches in height. The imperial gallon of England contains 277.274 cubic inches, and is equivalent to 1.2 U.S. gallons and at 62° Fah. weighs 10 lbs. A cubic foot contains 74805/10000 (71/2 nearly) U.S. gallons, and weighs 62355/1000 (621/3 nearly) lbs. A barrel = 311/2 gallons. 1 hogshead = 2 bbls. = 63 gallons. The strength of a tank is of the first importance; 2351/2 gallons of water weigh as much as a ton of coal, but unlike the latter, it presses in all directions. Immense losses both of life and property have been caused by the “bursting” or giving way of tanks; particularly of those of a considerable size and elevation. Fig. 596. Note.—Tank Valves. The “Corcoran” valve is made for either side or bottom outlet and for 1, 11/4, 11/2, 2 and 21/2 inch pipe; its action is automatic; the pull by which it is operated is controlled by a ratchet. This valve closes the pipe inside the tank. It thus becomes easy to empty the pipes in order to prevent freezing. The hoops, lugs and lock nut nipples are important parts of a well constructed tank. The foundations upon which tanks are supported should be carefully considered, as the average weight of a well made tank, when full of water, is about five tons to 1000 gallons. The following table gives the capacity of round tanks or cisterns for each 12 inches in depth, if the tank is 24 inches deep instead of 12 inches, the result would be, twice the number of gallons. Table.
The contents of cisterns and tanks are estimated either in gallons or in cubic feet. The weight of water in any cistern or tank can be ascertained by multiplying the number of gallons by the weight of one gallon, which is 81/3 pounds, 8.333. For instance, taking the largest cistern in the above table containing 3671 gallons: 3671 × 8.33 = 30579.43 lbs. (nearly). If the cistern is rectangular, the number of gallons and weight of water are found by multiplying the dimensions of the cistern to get the cubical contents. For instance, for a cistern or tank 96 inches long, 72 inches wide, and 48 inches deep, the formula would be: 96 × 72 × 48 = 331,776 cubic inches. As a gallon contains 231 cubic inches; 331,776 divided by 231 gives 1,436 gallons, which multiplied by 8.33 will give the weight of water in the cistern. Fig. 594. For round cisterns or tanks, the rule is: Area of bottom on inside multiplied by the height, equals cubical capacity. For instance, taking the last tank or cistern in the table: area of 24 inches (diameter) is 452.39, which multiplied by 12 inches (height) gives 5527.6 cubic inches, and this divided by 231 cubic inches in a gallon gives 23 gallons. Fig. 595. Rule for obtaining the contents of a barrel in gallons. Take the diameter at the bung, then square it, double it, then add square of head diameter; multiply this sum by length of cask, and that product by .2618 which will give volume in cubic inches; this, divided by 231, will give result in gallons. STRAINERS FOR SUCTION PIPES,It is very desirable to place an efficient strainer on the suction pipe of a pump where there is the least suspicion that the water contains any sediment or floating matter. Several of these useful pump attachments have been already shown, connected with pumps, in previous sections of this work, but a few more are here added. Fig. 597 exhibits a cross section of a strainer of large capacity of long and satisfactory use. It has a semi-cylindrical vessel located in one side of the side pipe. Holes are drilled through the flat side extending across the diameter of the side pipe; any floating matter which will not pass through the holes collects in this strainer vessel and may be easily removed. Figs. 597 and 598. Fig. 598 represents a longitudinal section of this strainer. The top of the chamber is covered by a bonnet secured by a claw having one bolt, so that by unscrewing this bolt the claw and bonnet may be unfastened and the settling chamber with perforated plate withdrawn. A suction valve with double strainer is represented by Fig. 599, in which the outer screen is raised for cleaning. In lowering, it is guided to its place by the cage around the foot valve chest, as will be seen in Fig. 600, which is a sectional view of This foot valve is a “double clack” hinged in the center. There are no openings or perforations in the bottom plate. Fig. 601 is a very convenient form of strainer for large pipes and where it is an advantage to have the strainer in the engine-room or near the pump. This strainer, like Fig. 597, can be lifted out for cleaning by removing the claw and bonnet. The chamber may be washed out by removing the plug at the bottom. Fig. 599. Fig. 600. A most convenient vacuum chamber and strainer is represented in Fig. 602; it is located near the pump. By removing the suction chamber the basket or strainer may be lifted out by the handle under the arrow. The outlet is generally attached directly to the pump. The pump may be charged by removing the “priming plug” and inserting a hose, with water turned on. Steam boiler feed water impurities consist mainly of chemical substances which are unaffected—as may be readily supposed—by mechanical devices just described; these impurities are largely invisible being dissolved in the water and hence, also, considering their variety, are most difficult to contend with. How to avoid the actual evils arising from the presence of foreign matter in feed water is of the first importance in steam economy; enormous losses of money, danger to life and property are involved in it. It has been said that there are more millions of treasure to be made by properly “treating” the water which enters the steam generators of the world than can be extracted from its gold mines. Fig. 601. Fig. 602. Note.—Strangely, investigation has proved that water of this purity rapidly corrodes iron, and attacks even pure iron and steel more readily than “hard” water does, and sometimes gives a great deal of trouble where the metal is not homogeneous. Marine boilers would be rapidly ruined by pure distilled water if not previously “scaled” about 1/32 of an inch. To deal properly with this subject the science of chemistry must be largely drawn upon; chemically pure water is that which has no impurities, and may be described as colorless, tasteless, without smell, transparent, and in a very slight degree compressible, and, were a quantity evaporated from a perfectly clean vessel, there would be no solid matter remaining. Now, in dealing with the impurities inside a boiler, it is to be observed that in no sense do they change the essential nature of water itself. The impurities are simply foreign bodies, which have no legitimate place in the boiler, and are to be expelled as thoroughly as possible. The chemical substances to be eliminated are indicated in the note below. Water, on becoming steam, separates from the impurities which it may have contained, and these form sediment and incrustation. This is an important fact. Corrosion is simply rusting or wasting away of the surfaces of the metals. Incrustation means simply a coating over. Several approved recipes and “notes” of instruction for removing sediment and incrustation from steam boilers will be found near the close of this volume.
The percentage only of each ingredient the scale is composed of is given, as it cannot be told how much water was evaporated to leave this amount of solid matter. THE WATER METER.Water meters, or measurers, are constructed upon two general principles: 1, an arrangement called an “inferential meter” made to divert a certain proportion of the water passing in the main pipe and by measuring accurately the small stream diverted, to infer, or estimate the larger quantity; 2, the positive meter; rotary piston meters are of the latter class. Fig. 603. Figs. 604, 605. The distinctive difference between the two is, that the positive meter measures water by means of a chamber alternately filled and emptied. In most of these the flow of water ceases when, by any derangement, the motion of the piston is interrupted. But neither the motion nor the stoppage of the inferential meter has any effect upon the water delivery, so Fig. 603 is a perspective view of the Worthington water meter, the details of which are shown in the Figs. 604 and 605, the recording or “dial” mechanism is also shown in Fig. 606. The internal arrangement of the meter is shown in longitudinal section, Fig. 604, and the transverse section, Fig. 605, on the opposite page. Fig. 606. The plungers, AA, are closely fitted into parallel rings. The water passes through the inlet and port I, and is admitted under pressure into chamber, D, at one end of each plunger alternately, while the connection is made between the chamber at the other end of the outlet. Thus, the plunger in moving displaces its volume, discharging it through its outlet. The arrangement is such that the stroke of the two plungers alternates, the valve actuated by one admitting pressure to the other. The plungers are brought to rest at the end of the stroke by the rubber buffers, EE. One plunger imparts a reciprocating motion to the lever, F, which operates the counter movement through the spindle and ratchet gear as shown. Thus, it will be seen that the counter is arranged to move the dial pointers once for every four strokes or displacements, and that water cannot pass through the meter without registration, for, in order to pass through, it must be displaced by the plungers, and, therefore, recorded by the movement of the lever and counter mechanism; nor can there be an over-registration, because the plungers cannot move without displacing the fluid. To read the dial. The counter usually registers in cubic feet, one cubic foot being 7.48 gallons U. S. standard. When desired for special services, counters are furnished reading in U. S. gallons, Imperial gallons, and Hectolitres. This counter is read in the same way as the registers of gas meters. The following example and directions may be of use to those unacquainted with this method: Fig. 607. If the pointer is between two figures, the smaller one must invariably be taken; suppose the pointers of the dial stand, as shown in Fig. 606; starting at the dial marked 10 cubic feet, we get the figure 4; from the next marked 100 cubic feet, the figure 7; from the next marked 1,000 cubic feet, the figure 8, and from the next marked 10,000 cubic feet, the figure 6; the reading is 6,874 cubic feet. The pointer on the 100,000 cubic foot dial being between the 0 and the 1 indicates nothing. By subtracting the first reading taken from that taken at the next observation, the consumption of water for the intermediate time is obtained. A steam trap is an apparatus to remove the water of condensation from steam pipes for heater coils and radiators without permitting steam to escape; the steam trap is also used to remove the water of condensation or entrained water caught in steam separators, located near the steam engine in the connecting pipes between the engine and boilers. The problem of saving the water of condensation without allowing the escape of steam is a difficult one, in view of the early wear of the valves and the valve seats. Fig. 607 represents the Anderson improved steam trap. This trap shows at all times what it is doing by the position of the water in the glass gauge attached to the side of the trap and in front. The water of condensation enters at the upper right-hand side, A, Fig. 608, where all scale and dirt from the pipes are caught in the settling chamber which contains a strainer. This strainer can be lifted out with its contents of dirt and scale and replaced in a few moments by unscrewing the plugs, shown in Fig. 607 just above the inlet. The discharge is connected at the lower left-hand side. The bonnet which contains the valve float and lever can be removed without breaking any pipe joints, or the valve and seat may be removed by simply unscrewing the cap, H, at the lower left-hand side without disturbing the bonnet at all. It will be understood that this trap does not dump, but the discharge of water is regulated by a ball float and valve, hence there are really but two working parts to this trap, viz.: the ball float and valve. Water is permitted to pass this trap as fast as it comes along, and no considerable quantity ever accumulates within this trap at any one time. Fig. 608. The sectional view, Fig. 608, gives a fair idea of the interior of this trap, being a longitudinal section on center line. The by-pass valve, C, so-called, is not a valve, but is simply a With three inches of water in the glass the valve is closed and sealed so that no steam can escape. The dotted line represents the water level. The sediment chamber, E, prevents dirt and scales in the pipes from getting into the valve. The ball float is made of seamless copper with heavy bands to prevent the ball from collapsing under high pressure. These traps work on all pressures from 150 pounds pressure down, and are also made for higher pressures in special cases—will work against back pressure and with exhaust steam alone—are made in seven sizes, i.e., from 1/2 inch to 21/2 inches, inclusive. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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