A Description of the Differential Expansive Pumping Engine: Giving Practical Examples of Engines at Work, and a List of Some of the Engines Already Made, with Useful Notes and Formula for Pumps and Pumping Engines

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Spon, 1880 - Pumping machinery - 36 pages
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Page 25 - That an abundance of water is stored up in the new red sandstone, and may be obtained by sinking shafts and driving tunnels about the level of low water. That the sandstone is generally very pervious, admitting of deep wells drawing their supply from distances exceeding one mile...
Page 12 - ... and in that way the engine checks itself. So perfect is the action of this gear that when properly adjusted the full load may be thrown suddenly off the engine without any injury resulting. The effect of a sudden loss of load is to reverse the action of the valves, and to throw the steam against the motion of the piston, stopping it before the end of the stroke. Many instances of this have occurred in practice * ' Direct-acting Pumping Engines and Pumps,' by Henry Davey, MIME (Proceeding!
Page 5 - ... the greatest economy of fuel. The chief peculiarity in the invention, is the simple manner in which the engine is made perfectly safe in working under all conditions of load, automatically varying its supply of steam in proportion as the load. on the engine increases or decreases; the distribution of steam being such, that the pumping is performed without shock.
Page 12 - ... less resistance to encounter, moves off at a higher speed, and sooner overtakes the subsidiary piston, moving at a constant speed under the control of the cataract ; the closing of the main valve G is consequently accelerated, causing an earlier cut-off. But with a heavy load...
Page 11 - Fig. 12, is actuated by the piston rod through a lever H, working on a fixed centre, -which reduces the motion to the required extent and reverses its direction. The valve spindle is not coupled direct to this lever, but to an intermediate lever L, which is jointed to the first lever H, at one end; the other end M, is jointed to the...
Page 31 - D = diameter of pipe in inches; H = head of water in feet; L = length of pipe in feet; W = cubic feet of water discharged per minute...
Page 12 - ... being made to move at a uniform velocity by means of the cataract K, the cut-off consequently takes place at the same point in each stroke, so long as the engine continues to work at a uniform speed ; but if the speed of the engine becomes changed in consequence of a variation in the load, — if for instance the load be reduced, causing the engine to make its stroke quicker, the subsidiary piston has not time to advance so far in its stroke before the cut-off takes place, and the cut-off is...
Page 11 - G, consequently receives a differential motion compounded of the separate motions given to the two ends of the lever, L. If this lever had a fixed centre of motion at the outer end, M, the steam would be cut off in the engine cylinder at a constant point in each stroke, on the closing of the...
Page 14 - It will be seen that there are two handwheels and a lever attached to the cataracts. The function of the large wheel is to regulate the speed of the engine during the stroke; the small wheel is for regulating the pause between the strokes, whilst the hand lever enables the engineman to hand work the engine.
Page 11 - the position of the cut off point is shifted and depends upon the position of the subsidiary piston at the moment when the slide valve closes. At the beginning of the engine stroke, the subsidiary piston is moving in the same direction as the engine piston, as shown by the arrows in Fig.

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