HYDRAULICS & PNEUMATICS Conditioning and Distribution of Compressed Air Presented by: Dr. Abootorabi

Conditioning and Storing Pneumatic System Air Maximum pneumatic system operating efficiency is achieved when system compressed air is: Consistently clean Free from moisture At a relatively uniform temperature

Conditioning and Storing Pneumatic System Air Atmospheric air contains dirt under even the best of operating conditions.

Conditioning and Storing Pneumatic System Air Pneumatic systems need to carefully filter the air taken into the compressor intake to extend the service life of: Compressor Other system components

Conditioning and Storing Pneumatic System Air Air at construction sites is dirty.

Conditioning and Storing Pneumatic System Air Painting requires very clean air.

Conditioning and Storing Pneumatic System Air The temperature of both the intake and compressed air is important: Temperature changes are reflected in air pressure and volume per the general gas law Temperature influences the ability of air to retain water vapor

Conditioning and Storing Pneumatic System Air Air in a pneumatic system may be cooled before, during, or after compression: Intake air temperature usually depends on the location of the compressor air intake Intercoolers and aftercoolers are used to remove heat of compression

Conditioning and Storing Pneumatic System Air Intercoolers cool compressed air between the stages of a multiple-stage compressor. Aftercoolers cool the air after the air has been compressed. Either air or water can be used as the cooling medium in these devices.

Conditioning and Storing Pneumatic System Air Water vapor in air is referred to as humidity: Essential to our natural environment Can cause problems in a pneumatic system when the temperature of the compressed air drops to the dew point and the vapor condenses into liquid water

Conditioning and Storing Pneumatic System Air Liquid water in a pneumatic system can: Wash away lubricants Increase component wear Cause inconsistent system operation Lower the finished quality of products directly using the air in the manufacturing process

Conditioning and Storing Pneumatic System Air Liquid water forms in system lines and components whenever the air temperature decreases to the dew point. The first step in reducing the liquid water in compressed air is to locate the atmospheric air intake of the compressor in a protected area.

Conditioning and Storing Pneumatic System Air Condensation of the water vapor in compressed air can occur in: Aftercooler units Moisture separator System receiver Distribution system

Conditioning and Storing Pneumatic System Air Specific air dryers can be used in pneumatic systems to remove moisture: Chemical desiccant Refrigeration units Specialized membranes

Conditioning and Storing Pneumatic System Air The receiver is the storage unit for compressed air. Typically, the receiver is a metal, cylindrical tank with domed ends. In addition to air storage, the receiver: Dampens system pressure pulsations Removes water vapor from system air In smaller systems, serves as the mount for the prime mover and compressor

Conditioning and Storing Pneumatic System Air Formulas are available for calculating the volume needed for a receiver. These formulas consider: Cubic feet of free atmospheric air needed per minute Desired cycle time Atmospheric, initial receiver, and final receiver air pressures

Air-Distribution System The air distribution system delivers high-pressure, conditioned air from the receiver to workstations with a minimum of pressure drop. The type of distribution system depends on the size of the facility and the level of demand for compressed air.

Air-Distribution System Four general categories of air distribution systems are used with pneumatic systems: Centralized grid with fixed piping Decentralized grid with fixed piping Loop system with fixed piping Flexible hoses for portable compressor systems

Air-Distribution System Centralized grid has one centralized compressor station and one line network for a facility. Decentralized grid has individual compressors in several locations providing air to smaller distribution networks.

Air-Distribution System Centralized grid:

Air-Distribution System Decentralized grid:

Air-Distribution System Loop system has a main line that forms a continuous loop with compressors located at one or more locations. This design provides maximum airflow with a minimum of pressure drop between the compressors and the individual workstations.

Air-Distribution System Loop system:

Air-Distribution System Special attention must given to the setup of a hose air distribution in order to minimize pressure drop: Minimize hose length Reduce the number of couplings Eliminate kinks in the hose Care must be taken to protect the hoses from abrasion in the work environment.

Air-Distribution System Typical hose distribution system: DeVilbiss Air Power Company

Air-Distribution System Proper sizing of pipe for a fixed air distribution system is difficult. Most systems operate under a variety of work conditions: Multiple workstations Varying actuator loads Intermittent actuator operation

Air-Distribution System Sizing is based on: Rated actuator air consumption Estimate of the time actuators are actually operating Estimate of the percentage of maximum load delivered during actuator operation

Air-Distribution System The pipe in air distribution lines should be installed with a pitch of 1 per 10 of line: Allows liquid water to drain to water traps Water can be remove from traps either manually or with automatic drain devices

Air-Distribution System Drop lines lead from the main air distribution line to the workstations: Should be attached to the top side of the distribution line This prevents water in the distribution lines from entering the workstation lines

Air-Distribution System Proper slope and drop line installation:

Final Preparation of Air at the Workstation Final preparation of air at a workstation is accomplished by an FRL unit: Air filter Pressure regulator Lubricator

Final Preparation of Air at the Workstation Typical FRL unit:

Final Preparation of Air at the Workstation FRL air filter removes: Airborne dirt remaining in the atmospheric air compressed in the system Rust and scale from the interior of the distribution lines Liquid water that has condensed in the drop line Atomized oil from the operating compressor

Final Preparation of Air at the Workstation Typical air filter uses centrifugal force and porous filter material to remove unwanted materials from system air: Inlet passageway swirls the incoming air, creating a centrifugal force that separates air and contaminants Porous filter material traps other undesirable materials

Final Preparation of Air at the Workstation Typical FRL air filter: IMI Norgren, Inc.

Final Preparation of Air at the Workstation FRL filters typically have a drain.

Final Preparation of Air at the Workstation The pressure regulator in an FRL unit reduces system distribution line pressure to the level needed by workstation tools and circuit actuators. This unit is also necessary as air pressure in the distribution line fluctuates due to varying air demands and the characteristics of compressor-capacity control.

Final Preparation of Air at the Workstation The lubricator in an FRL unit meters oil into pressurized system air at the workstation. This provides lubrication for system valves, actuators, and air-powered tools.

Final Preparation of Air at the Workstation Typical FRL lubricator: IMI Norgren, Inc.

Final Preparation of Air at the Workstation Rapidly moving system air passing through a lubricator breaks up droplets of oil, forming a mist or fog. This mist is transported through the workstation lines to system components.

Final Preparation of Air at the Workstation

Final Preparation of Air at the Workstation

Distribution System Conductors and Fittings Effectively moving compressed air through a distribution system requires appropriate conductors and connectors. Conductors can be classified as: Rigid Flexible

Distribution System Conductors and Fittings Pipe is the most common rigid conductor. Hose is the most common flexible conductor. Conductors must be properly sized and assembled for compressed air to be transported from the compressor to actuators with minimal pressure drop.

Distribution System Conductors and Fittings Conductors and the associated fittings must be properly sized. IMI Norgren, Inc.

Distribution System Conductors and Fittings Various types of hose are available: Atlas Copco

Distribution System Conductors and Fittings Hose selection, application, and maintenance are critical to assure air distribution with a minimum loss of pressure: Hoses should be no larger than necessary Use a minimum number of fittings Layout lines to eliminate kinks and reduce the number of bends

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