Hydraulics principles

Bloodgood, D.E., Teletzke, G.H., Pohland, F.G. (1959). Fundamental hydraulic principles of trickling filters. Sewage and Industrial Wastes 31(3) 243-253. 

Lowered reactor pressure and temperature as compared to present-day PWR plants Departures from current LWR technology are limited to the following areas Thermal-hydraulic principle of the reactor... 

Ghosh, S. N. and V. R. Desai. 2006. Environmental Hydrology and Hydraulics Eco-Technological Practices for Sustainable Development. Enfield, NH Science Publishers. Focuses on small-scale water projects and sustainable practices covering water uses, hydraulic principles and design, water hazards and management, and eco-technological practices for sustainable development. 

The principle of operation of the hydraulic reciprocating pump is similar to the beam pump, with a piston-like sub-surface pump action. The energy to drive the pump, however, is delivered through a hydraulic medium, the power fluid, commonly oil or water. The power fluid drives a downhole hydraulic motor which in turn drives the pump. A separate surface pump delivers the hydraulic power. The power fluid system can be of the closed loop or of the open type. In the latter case, the power fluids are mixed with the produced fluid stream. The performance of the hydraulic pump is primarily monitored by measuring the discharge pressures of both surface and sub-surface pumps. 

An indatable diaphragm or membrane has been used in membrane plate presses closely related to the conventional plate and frame presses. A pressure filtration period is foUowed by compression with the hydraulically operated membrane or by a hydraulically operated ram if dexible rim seals are fitted. This principle also is used in vertical presses that use either one or two endless cloth belts indexing between plates. Indatable membrane also may be used on a cylindrical filtration surface with or without a preceding pressure filtration stage. 

Additional information on mass-flowmeter principles can be obtained from Yeaple (Hydraulic and Pneumatic Power and Control, McGraw-HiU, New York, 1966, pp. 125-128), Halsell [In.strum. Soc. Am. J., 7, 49-62 (June I960)], and Flanagan aud Colmau [Control, 7, 242-245 (1963)]. Information on commercially available mass flowmeters is given in the latter two references. 

Liquid-Sheet Breakup The basic principle of most hydraulic atomizers is to form a thin sheet that breaks via a variety of mechanisms to form ligaments of liquid which in turn yield chains of droplets. See Fig. 14-86. 

The permeability relative to a pure liquid, usually water, may be determined with the help of different devices that operate on the principle of measurement of filtrate volume obtained over a definite time interval at known pressure drop and filtration area. The permeability is usually expressed in terms of the hydraulic resistance of the filter medium. This value is found from ... 

At all points in a system, the static pressure is always equal to the original static pressure less any velocity head at a specific point in the system and less the friction head required to reach that point. Since both the velocity head and friction head represent energy and energy cannot be destroyed, the sum of the static head, the velocity head, and the friction head at any point in the system must add up to the original static head. This is known as Bernoulli s principal, which states For the horizontal flow of fluids through a tube, the sum of the pressure and the kinetic energy per unit volume of the fluid is constant. This principle governs the relationship of the static and dynamic factors in hydraulic systems. 

In this case, the fluid column has a uniform cross section, so the area of the output piston is the same as the area of the input piston, or 10 square inches. Therefore, the upward force on the output piston is 100 pounds and is equal to the force applied to the input piston. All that was accomplished in this system was to transmit the 100 pounds of force around the bend. However, this principle underlies practically all mechanical applications of hydraulics or fluid power. 

Modules Every module design used in other membrane operations has been tried in pervaporation. One unique requirement is for low hydraulic resistance on the permeate side, since permeate pressure is very low (0.1-1 Pa). The rule for near-vacuum operation is the bigger the channel, the better the transport. Another unique need is for heat input. The heat of evaporation comes from the liquid, and intermediate heating is usually necessary. Of course economy is always a factor. Plate-and-frame construction was the first to be used in large installations, and it continues to be quite important. Some smaller plants use spiral-wound modules, and some membranes can be made as capillary bundles. The capillary device with the feed on the inside of the tube has many advantages in principle, such as good vapor-side mass transfer and economical construction, but it is still limited by the availability of membrane in capillary form. 

Mineral Oil Hydraulic Fluids and Polyalphaolefin Hydraulic Fluids. While very little information dealing explicitly with the food chain bioaccumulation of this category of hydraulic fluids is available, the principle petroleum hydrocarbon constituents do not appear to have a significant tendency for... 

In principle, the steady-state pipeline network problems can always be solved by the transient solution methods after allowing sufficient time steps for the solution to reach steady state. This possibility was discussed by Nahavandi and Catanzaro (Nl) who made a comparison of a transient solution method with the Cross method of balancing flows (R4). For the particular 35-node and 45-branch hydraulic network problem tested, the transient solution method took 108 seconds as compared with the 134 seconds required by the Hardy-Cross method. (See also Section V,A,2.)... 

Hydraulic pressure stimulation (fracturing) of oil and gas wells has now accumulated 40 years of history and experience. The actual practice and application of this technique supports a multi-billion dollar service industry which annually utilizes in excess of 130 million pounds of chemical additives. This chapter will describe the fracturing fluids that are used and some of the additives, their purpose, and the principles that make their use effective as well as necessary. Information presented will update a body of review literature that covers the prior years of fracturing(1). Chemicals are added for specific purposes which are identifiable by their descriptive title. Veatch02) has compiled a thorough general list of the additives added to fracturing fluids. 

Flow in undisturbed rock normally is radial toward a site of lower pressure (the wellbore). The fracture crack created by high pressure injection usually forms perpendicular to the least principle stress that exists in the rock. The induced fracture intersects and disrupts the radial flow pattern such that flow becomes linear and more direct to the well. This phenomenon has been intensively examined and discussed by authors working in the discipline of rock mechanics as applied to hydrocarbon reservoirs. Hydraulic fractures created in oil and gas wells grow mainly vertically, parallel to the wellbore as depicted in Figure 1 and extend on either side of the perforated wellbore as "wings11 (7-11). 

The principles of operation of a hydraulic actuator are like those of the pneumatic actuator. Each uses some motive force to overcome spring force to move the valve. Also, hydraulic actuators can be designed to fail-open or fail-closed to provide a fail-safe feature. 

Long-Stroke Sensor for Hydraulics and Pneumatics eddy current principle Micro-Epsilon strokeSENSOR... 

Because of the basic requirements of collection and transport, sewer networks are normally dealt with from a physical point of view, i.e., the hydraulics and sewer solids transport processes have been focal points. From this point of view, new design and operational principles have been developed, to a great extent supported by numerical procedures and the ever-increasing capacity of computers. Under wet-weather conditions, the hydraulics and solids transport phenomena in a sewer play a major role, and the chemical and microbiological processes are typically of minor importance. Not surprisingly, interests devoted to urban drainage have focused on the physical behavior of the sewer. 

Fig. 16.12 Principle and advantages of the falling film electrolyser. Advantages include improved mass and heat transfer low gas content in electrolyte low concentration difference constant hydraulic pressure low expected voltage of 2.70 V at 3 kA m-2 leading to power consumption reduction of 70 kWh per tonne of NaOH at 4kA m-2, including circulation pumps and small element depth. 

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