WHEELS ANCIENT AND MODERN.

WHEELS ANCIENT AND MODERN.

(Specially written for FIRE AND WATER.)

FOREIGN engineers, especially those of France, claim that, although American engineers have produced first-class turbines, they have failed to utilize to the best advantage falls of less than two and one-half feet head for draining their wheels. The French engineers claim they can do better than that, and can turn to account falls as slight as four inches. They quote in proof of the fact that at Maquens, near Carcassonne, a “turbinette”—so they style their Lilliputian wheels—working with this slight head of water develops a power of nine kilograms, raising the water to the height of thirtyfivemeters (llSfeet). AtAixen-Savoie, wateris raised to the height of fifty-five meters (180 feet), with an available fall of only twenty-five centimeters (ten inches). At Toulouse, also, a turbine working with a column of fifty centimeters yields a force of fifteen horse power. In order to obtain good results, they say that all that is required is to arrange that the turbine be constantly under water.

The tiret thing necessary in a water power is, of

LEFFEL ELECTRIC MINING PLANT AND CASCADE WATER WHEEL.

course, to know what amount of head and fall can be secured and then what quantity of water the stream affords for driving the turbines. This is arrived at by a very simple process of measurement already described in one of the present series of articles (FIRE AND WATER, May 27, 1899, pp. 168, 169). An important matter in measuring small streams is the possibility of damming or holding the water and using it a part of the time instead of constantly. If the water is held for twelve hours and the whole quantity used in the next twelve hours, with the supply that the stream affords in the same time, the power of the stream would be doubled for the twelve hours and would give a better effect than if used constantly.

The next consideration is that of the proper method of setting turbine wheels, such as the Victor and others already described. The Victor, like others, is a flume wheel constructed to rest by the flange of its case or stationary part upon the floor of the flume over an aperture in the floor through which the wateris discharged. Whether the flume is round or square, its internal diameter should be between five

feet, six inches and twenty feet, six inches—based upon a head of twenty feet or less. The size of the wheel should be from twelve inches to forty-eight inches. Across every flume should be provided a rack, to prevent the passing of drift wood and other rubbish into the wheel. The frame of the flume can hardly lie too strong, esi>ecially its lower timbers and floor. The floor timbers should be placed in the direction of the current, with their upper surface low enough to insure the end of the cylinder being submerged at least two inches in standing tail-water when at its lowest stage. The forebay leading to the flume should be of sufficient width and depth to allow the water to pass to the wheel at a velocity never exceeding one and one-half feet per second, and should be free from abrupt turns or cramped passages which break the water into eddies, thereby diminishing its force and reducing the working head. The tail-race should be of the same capacity, and, when practicable, of sufficient depth below the surface of the stream into which it empties, to have at least two feet of dead water standing the entire length of the tail-race when the wheels are not in motion; and, when a large amount of water is to be used on the

wheels, this depth of dead water should be increased to three or four feet. This, being displaced by the water as it is discharged from the wheel, at once conforms to the general level of the water in the tail-race, river, or receiving canal. Thus no head is lost.

To ascertain the requisite size of flumes and tailraces: Given the tables of power, etc. (See above), and the proper size of wheel to produce the required power, and also the number of cubic feet of waterthe wheel will discharge per minute, then divide the number of cubic feet by 85, and the quotient will be the area in square feet required in the cross section of the head or tail-race for every wheel used That is to say—for every eighty-five cubic feet of water used by the wheel or wheels per minute, there should be one square foot in cross section of all the water passages leading to. and from the wheel, including, of course, the opening under the flume, through which the water passes after leaving the wheel. Larger water courses than indicated by the above rules are not objectionable, but desirable; for the nearer a state of rest the water can be brought to before entering and leaving the wheel, the better will be the results obtained.

(To be continued.)

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WHEELS ANCIENT AND MODERN.

1

WHEELS ANCIENT AND MODERN.

(Specially written for FIRE AND WATER.)

THERE is a demand for water motors, and their success is guaranteed if they economize water, act efficiently, and cost less than overshot wheels or turbines. This is proved by the fact that in many instances turbines have been removed and their place has been taken by large and costly overshot wheels, whose chief merit is that in localities where water is scarce part of the time the overshot wheel uses this small quantity economically. The best turbine wheels cannot run at part gate with any showing of economy, unless at least one-half the quantity of water required at full gate is used. This difficulty, however, seems to have been fully overcome by the Woodard water motor, manufactured by the W. J. Clark company, of Salem, Ohio. This motor is the invention of a practical mill man, of large experience in the use of all kinds of water wheels, and has been successfully tried, and is in daily use for three years at the inventor’s mill at Mannsville, N. Y. It is still more economical of water than an overshot wheel and also costs considerably less. It consists of a series of buckets on a chain, moving vertically downwards—the water flowing into the buckets at the highest point and emptying at the lowest point, the chain transmitting the force due to the weight of water to a wheel and shaft. This idea is not entirely new, but previous attempts have been unsatisfactory, and the success of the Woodard device is due to the novel and thoroughly mechanical design of the chain and the correct shape and adjustment of the buckets, together with the method of flowing the water into the buckets, which utilizes almost the full head in the forebay equally as well as when turbines are used. As will be seen from fig. 1, the water goes into the buckets in a nearly vertical direction—the buckets passing down in a vertical line and turning quickly and completely upside down when at the surface of the water in the tail-race. It will be noticed that each bucket begins to fill before it gets down to a level position, and also that at the same time the filling of the bucket next below it continues until after the upper bucket becomes level and cuts off the water from the bucket below it. As soon as each bucket begins to empty into the tail-race it turns away from the bucket above it, so that its contents discharge promptly without striking the bucket next to it. These features are peculiar to this motor. By having the correct head of water above the gate opening in the chute, the water will issue at double the speed of the buckets, and all the force of the head will be utilized, except the small amount lost by friction of the water through the gate opening—making it equal to a turbine wheel in this respect. The shape and position of the chute is such that the front edge of the bucket cuts into the issuing stream in advance of the bottom corner, in passing from A to B (fig. 1.), preventing splashing or loss of water and filling each bucket without disturbing the shape of the stream or retarding its flow. The bucket, after filling, moves rapidly downwards in a straight line, and, like all heavy bodies, water tends strongly to keep on going in a straight line, when in motion, so that, when the bucket reaches the bottom and turns quickly from under its contents, the water drops without resistance into the tail-race. The chute and gate are cast iron, the seat and gate being planed smooth, making it watertight when closed, preventing waste of water from leakage, and avoiding trouble from water dripping and freezing up the motor in cold weather. The lower wheels of the motor are on a shaft which runs in self-adjusting boxes arranged to slide vertically, so that the weight of the wheels, shaft, and boxes keeps the chain taut. The links which are bolted to the back of the buckets are steel castings with Vshaped projections, which fit in the grooved wheels. Brass bushes, tightly fitted into the steel links, work on cold rolled steel pins. In case of undue wear or accidental chafing of the pins, the bushes and pins may be quickly renewed at small cost. The wheels on the driving shaft are of cast iron, with chilled grooves to flit the projections on the steel links, which makes them very durable. The buckets are of tough steel plate, the body being formed of one piece riveted to flanged ends and thoroughly braced to make it stiff and strong.

The advantages claimed for the Woodard motor over the ordinary overshot wheel are: (1) From its construction, already explained, it furnishes more driving power from any given amount of water; (2) its shaft may run at a higher speed than it is practicable to run the shaft of an overshot wheel, and less gearing is, therefore, required to speed the machinery as desired; (3) it occupies much less space and requiressmaller and lessexpensivefoundations and supports; (4) it has no heavy or bulky parts and is, therefore, easier to transport in locations difficult of access than either an overshot or turbine wheel, while its construction is so simple that it can be erected and put in operation very quickly by comparatively inexperienced persons; (5) if a bucket gets damaged it can be quickly removed and replaced at small cost, and leaks show up immediately; (6) the buckets move apart from each other while admitting and discharging the water, and, consequently, fill and empty quicker than is possible with overshot wheels; (7) it costs much less and has all the advantages of an overshot wheel over a turbine. In comparison with jet wheels, for any head not* exceeding sixty feet the Woodard motor is equal in efficiency at full gate and superior at part gate to the various makes of jet wheels.

WOODARD WATER MOTOR—SIDE VIEW (FIG. 1.)

The advantages over turbine wheels are: (1) It has higher efficiency at full gate and much higher at part gate—a difficulty turbine makers try to get over by installing a number of small turbines, thereby increasing the cost; (3) itneverclogs with rubbish or anchor ice, and so requires no screens; (3) it has no joints that can be forced to leak by a high head of water— it has only one simple flat gate, and has just enough head of water to keep it tight upon its seat-any leakage of the gate while runninggoing into the buckets and being saved; (4) it has no stuffing-boxes round running shafts to be kept watertight; (5) it has no main bearing, which is inaccessible while running, like the step-bearing of a turbine, but both bearings which carry the wheel may be examined and taken care of at any time.

The illustrations accompanying this article show (fig. 1) a side view of the Woodard water motor, showing the general arrangement of the buckets, chains, and whoels, together with a sectional view of the chute and forebay and the method of directing the water into the buckets; (fig. 2) another side view showing the chute arranged for running the motor in the same direction as an overshot wheel, when the conditions require it; (fig. 8) top view, looking down into the bucket and showing how the chains fit into the V-shaped grooves in the wheels on the driving shaft.

WOODARD WATER MOTOR—HIDE VIEW (FIG. 2.)WOODARD WATER MOTOR—TOP VIEW (FIG. 3.)