Compressor, pneumatic system

Air compressor (coal pneumatic system) Air compressor (ash pneumatic system) Firefighting equipment Detection Portable Hydrant system Springer system Panel... 

Pneumatic systems operate linearly like natural muscle pneumatic artificial muscles (McKibben artificial muscles) in particular are intrinsically compliant and can thus provide the give that natural muscle attains. Unfortunately, these systems require air compressors that are neither light nor small, and their response speed is limited by the ability to pump air into and out of the actuators. 

For engineers to use pneumatics, they must design a pneumatic system. As we noted in Chapter 2, a system is a group of related components that work together to achieve a process. A typical pneumatic system consists of a compressor, a reservoir, transmission lines, control valves, and actuators. These components are shown in Figure 11-13. 

The compressor is a device that increases the pressure of air and pumps the compressed air into a tank. The compressed air tank is called a reservoir. The compressed air is then routed to the desired location through transmission lines. Transmission lines are tubing through which the compressed air flows. Control valves regulate the flow of gases. The pneumatic system uses a cylinder with a movable piston to convert its fluid power into mechanical power in the form of linear motion. 

The pneumatic system comprises of various parts. The air or any other gas is pressed by the compressor through the pneumatic volume, capillary and pneumatic volume, which smoothen the flow and pressure at the measuring system inlet. The air flow is determined from the pressure difference along the flow capillary via a differential pressure sensor. The control of the volume of separating bubbles is arranged by a deflector located opposite to the capillary at a definite distance (Miller et al. 1994). The optimum internal gas volume of the instrument and selection of the right capillary are two important points in the design of the device as discussed below. 

Pneumatic System Components. The major components are a compressor, an air storage tank (receiver), an air-cleaning apparatus composed of a main line filter, an air dryer, and a mist separator, all connected by a series of hoses. These sections are followed by an air-conditioning section composed of a filter, regulator, and lubricator, then a controlling section made up of a directional control valve and a speed controller, and, finally, the actuator or operating system for which the pneumatic system was designed to power. 

The control air compressor is often the source of problems in pneumatic systems. Most compressors are designed for best performance when operating between 33 percent and 50 percent on-time. More than 50 percent on-time can result in objectionable levels of oil carryover if proper filtration procedures are not followed. Oil in the control air lines can destroy certain pneumatic devices or make them inoperable. Excessive on-time also may result in a significant energy loss. 

As another example of calculation and dimensioning of pneumatic conveying systems we consider an ejector shown in Fig. 14.20. In fluidized bed combus tion systems a part of the ash is circulated with the hot flue gas. The task of the ejector, is to increase the pressure of the circulating gas to compensate the pressure losses of the circulation flow. The motivation for using an ejector, rather than a compressor, is the high temperature of the flue gas. The energy... 

Three properties of gases must be well understood in order to gain an understanding of pneumatic power systems. These are its temperature, pressure, and volume. Physical laws that define their efficiency and system dynamics govern compressed air systems and compressors. These laws include ... 

Here is another case history of a compressed air system that was modified to near disaster. Details of this incident are unavailable, but some years ago a chemical plant or refinery with multiple reciprocating air compressors and pneumatic instruments systems decided to modernize. The modernization project replaced the air supply system. Economics favored one large centrifugal air compressor, and no backup air supply was installed. 

The nitrogen backup system was not reconnected. Later, when the instrument air compressor tripped, the auxiliary pneumatic power (nitrogen) was unavailable. Without the... 

Manual or automatic operation. Pumps and compressors often exist in manual, electrically operated, or pneumatically operated versions. Whenever practical, manual instruments should be preferred for laboratory applications, especially when a high-pressure set-up is used close to its limit. This forces experimenters to closely control the system by requiring their constant attention and vigilance. 

Most pneumatic conveyors operate under positive pressure, with a blower or compressor feeding air (or occasionally nitrogen) at 1 to 5 atm gauge pressure into the system. The ratio of solids to gas is usually higher than in vacuum systems. Sometimes the gas is recycled to the blower or compressor inlet in a closed system to save a valuable gas or prevent loss of dust to the atmosphere. 

The common theme in these microfluidic valving systems is the requirement of a vacuum or pressure pump/compressor that is used to actuate the pneumatic lines that are interfaced with the on-chip valves. These pneumatic lines, in turn, are usually controlled individually using computer-operated solenoid valves with the corresponding circuitry and manifolds. Various tubing can be used to connect each solenoid valve to the corresponding microfluidic interface. Interfacing to the device can be accomplished through a variety of means, which are not discussed here. Interested readers should refer to the cited works that are particularly relevant to their own research. 

A9.2.7 Pneumatic Driving System. The.incoming air from compressor is cleaned, filtered, and dehumidified before il accumulator tank. A relief valve controls the maximum pressiirei in the tank. A pressure regulator controls. the pressiire of the air prior to its entry into the pneumatic shuttle system through the solenoid-operated valves that govern... 

Gathering system compressors Engine exhaust, CO (XTO) Gathering system compressors Ertgine mchaust. CH (EPA) Pneumatic devices chemical injection pumps. CH (EPA) Gathering system losses. CH (EPA)... 

PC. Several components are needed to supply the compressed air cleanly and safely to the microfluidic systems, such as a compressed air tank or an air compressor, a pressure reducing valve, and air filters. The schematic of a pneumatic actuated multilayer microfluidic chip with its pneumatic supporting systems can be shown in Fig. 3. 

There are many applications which call for the use of clean, dry air, for example pneumatic instruments and air masks. This need is often met by using an oil-free compressor and aftercooler or by fitting an aftercooler and air drier to a conventional compressor. This reduces the need to fit and maintain local dirt eliminators as well as reducing the number of water traps required. In some factories, both systems are in operation. 

Many instrumentation systems and control devices require power sources, electrical or pneumatic, which have to be reticulated around the plant. The cost of instrument air is routinely underestimated, mainly because the associated piping costs are not appreciated when the P I diagrams are drawn up, but also because of a disinclination on the part of the instrument system designers to make any compromise on air-quality requirements. Even a few parts-per-million of oil may be regarded as unacceptable, with consequent cost increase to the air compressor. Both instrument power supplies and instrument air have to be provided in an adequately secure fashion in relation to the consequences of their failure. 

The air skates operate on air 7 volume supplied by a compressor or pneumatic supply system working at a pressure of 5-10 bar (500-1000 kPa). 

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