Hydraulic Ram


Also found in: Dictionary, Thesaurus, Idioms, Wikipedia.
Related to Hydraulic Ram: Hydraulic accumulator, hydraulic intensifier

hydraulic ram

[hi′drȯ·lik ′ram]
(mechanical engineering)
A device for forcing running water to a higher level by using the kinetic energy of flow; the flow of water in the supply pipeline is periodically stopped so that a small portion of water is lifted by the velocity head of a larger portion. Also known as hydraulic pump.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Hydraulic Ram

 

a water-raising device in which the delivery of water is achieved by an increase in water pressure caused by periodically occurring hydraulic impacts. The hydraulic ram was known as early as the 18th century. The theory for it was developed by N. E. Zhukovskii in 1907. A perfected design of the hydraulic ram was offered by the Soviet engineer D. I. Trembovel’skii in 1927.

During the initial acceleration period (see Figure 1), a valve (4) is briefly opened manually. The pressure of the backed-up water then causes a flow through the feed pipe (6) at an

Figure 1. Schematic diagram of a hydraulic ram: (1) upper tank, (2) pipeline, (3) pressure chamber, (4) and (5) valve, (6) pipeline, (7) reservoir, (p) force required to open valve, (h) water height for fall, (H) water height for rise

average flow rate Q. This flow is discharged through the valve (4). When the force of water becomes equal to the weight of the valve (4), the valve is raised. Quick closure of the valve (4) and the consequent abrupt cessation of water flow causes a hydraulic impact (water hammer). A drastic increase in pressure opens another valve (5), which releases a quantity of water at an average flow rate q < Q. During the work cycle, water enters the upper tank (1) through a pipeline (2), having overcome the pressure H > h. Compressed air in the pressure chamber (3) equalizes the water flow through the pipeline. At the end of the second cycle the pressure in the valve box decreases slightly. Therefore one valve (5) closes and the other valve (4) opens, thus assuring the automatic repetition of the work cycle. The efficiency of hydraulic rams depends on pressure. For the ratio H/h = 1 the efficiency equals 0.92. For H/h = 20 it is 0.26.

Hydraulic rams are used in cases where the available water supply significantly exceeds consumption and where it is possible to install the equipment below the level of the water source. They are used in agriculture, in small-scale construction to provide a water supply, and so on.

REFERENCE

Chistopol’skii, S. D. Gidravlicheskie tarany. Moscow-Leningrad, 1936.
Ovsepian, V. M. Gidravlicheskii taran i tarannye ustanovki, Moscow, 1968.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Electric machines are no problem, as there is no hydraulic ram pushing the screw.
The B42 allows electric motors and hydraulic rams to do the hard grind, forever the bane of crew and anyone not behind the wheel on other yachts.
The Hydraulic Ram eliminated the gear head motor and rack and pinion that were used on other Stedman cage mills, now costing less to maintain.
Today everything once again matches the old garden photographs taken during the Victorian era at Erddig, the summer flower beds are coming to their best with a display of pink and white Antirrhinums,blue Ageratum,Begonias and Verbena and the old Hydraulic Ram pump has been repaired and is lifting water to the fountain ponds.
The advantages of a hydraulic ram are these: First, when it works, it works like a charm, quickly and completely.
You can also choose a hand- or foot-powered hydraulic splitter, for which you supply the pumping power--the hydraulic ram does the rest.
A high-torque hydraulic ram holds a horizontally oriented pipe against a moving cutting plate studded with blades.
That made the device self-acting, and, as long as the water supply remained steady, the hydraulic ram was virtually a perpetual motion machine.
A small hydraulic ram was bought in to crack open the grate - but that too failed.
Features include 6-inch wide, flange structural steel guide columns and a hydraulic ram with 2.5-inch diameter dual pistons for smooth operation.
Double-walled manual feed hoppers can be positioned for feeding through the front, back, or side of the machine with a tangential feed hopper used for ingestion of material without the need of a hydraulic ram. Equipped with a feed opening of 21.7 by 19.3 inches (550 by 490 mm), the CLS also features a 12-inch-diameter drum-style rotor for efficient cutting of various scrap.
Its four 50-tonne gates are each operated by a 21-tonne hydraulic ram and control the river's flow.