Basic Pneumatics Module 2: Air Generation and Distribution

Basic Pneumatics

Module 2: Air generation and Distribution

PREPARED BY

Academic Services

August 2011

ATM 1132 – Basic Pneumatics

Module 2: Air generation and distribution

Module Objectives

After the completion of this module, the student will be able to:

. Identify the main parts of a pneumatic system. . Identify the main components of the pneumatic work station TP 101. . List the main parts in the compressed air preparation stage. . Identify the symbol of air compressor and its function. . Identify the symbol of air tank and its function. . Explain the purpose of using the cooling and drying unit. . Identify the main parts of the air service unit. . Identify the symbol of air filter and its function. . Identify the symbol of air pressure regulator and its function. . Identify the symbol of lubricator and its function. . Identify some important pneumatic accessories.

Module Contents

Topic Page No. 1 Introduction 3 2 Main parts in the compressed air preparation 3 3 Air compressor 4 4 Air tank 5 5 Cooling and drying unit 6 6 Shut off valve 7 7 Piping 7 8 Air service unit 9 9 Pressure regulator 10 10 Air lubricator 10 11 Manifold 11 12 Tubes and fittings 11 13 Pressure gauge 12 14 Safety precautions 13

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

1 Introduction Air generation and distribution The main function of the air generation and distribution is to provide the system with compressed air which is dry, clean, and at the required pressure. The compressed air supply for a pneumatic system should be adequately calculated and made available in the appropriate quality. Air is compressed by the air compressor and delivered to an air distribution system in the factory. To ensure that the quality of the air is acceptable, air service unit is utilized to prepare the air before being supplied to the control system. Malfunctions can be considerably reduced in the system if the compressed air is correctly prepared.

2 Main parts in the compressed air preparation 1- Air compressor 2- Air tank (Reservoir) 3- Air filter 4- Cooling and drying unit 5- Shut off valve 6- Piping 7- Air Service unit 8- Pressure regulator 9- Air lubricator 10- Manifold 11- Tubes and fittings 12- Pressure Gauge

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.1 Air compressor Air compressor is used to produce the compressed air for the system by the required volume and pressure.

As a rule, pneumatic components are designed for a maximum operating pressure of 800-1000 kPa (a) Air compressor (8 - 10 bar) but in practice it is recommended to operate at between 500-600 kPa (5 and 6 bar) for economic and safe use.

Due to the pressure losses in the (b) Air compressor distribution system, the compressor should provide pressure between 650-700 kPa (6.5 and 7) bar.

Fig. 2.1.a and Fig. 2.1.b are (c) ISO symbol of air compressor examples of air compressors while Fig. 2.1: (a) and (b) are examples Fig. 2.1.c shows the ISO symbol of of some practical air compressors. (c) ISO symbol of air compressor the air compressor.

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.2 Air Tank (reservoir)

An air reservoir should be fitted to:

. Store and stabilize

the compressed air. . Compensate the pressure (a) Air reservoir fluctuation.

. Cool the air.

(b) ISO symbol of air reservoir Fig. 2.2 (a) shows a real air tank while Fig. 2.2: (a) air reservoir. (b) Fig. 2.2 (b) shows the ISO symbol of an ISO symbol of an air reservoir. air reservoir.

2.3 Air Filter Compressed air filter (Fig. 2.3a) has the job of removing all contaminants from the compressed air flowing through it as well as water which has already condensed. The compressed air enters (a)A picture of a real air filter the filter bowl through guide slots. Liquid particles and larger particles of dirt are separated centrifugally collecting in the lower part of the filter (b) ISO symbol of the air filter bowl. The collected condensate must be Fig. 2.3: (a) air filter.(b) The drained before the level exceeds the ISO symbol of an air filter maximum condensate mark, as it will otherwise be re-entrained in the air stream.

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.4 Cooling and drying unit As the air comes out from the compressor very hot and humid; The cooling and drying unit is used to:

. Condensate the water vapor (humidity) from the compressed air.

. Reduce the compressed air

temperature. (cooling) (a)

The accumulation of condensate depends largely on the relative air humidity. The relative air humidity is dependent on the air temperature and the weather situation. To remove the humidity, we use

many types of air dryers, the very common and practical one (b) is by using a cooling unit which cool the air and at the same time remove the water vapor.

(c) Fig. 2.4 (a) and (b) show some Fig. 2.4: (a): and (b) are some examples of real air dryers, examples of real air dryers. while Fig. 2.4.c represents an (c) ISO symbol of air dryer. ISO symbol of air dryer.

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.5 Shut off valve It is used to open and close the compressed air supply manually.Fig. 2.5.a shows a sample of shut-off valve. Fig. 2.5.b represents the ISO symbol of the shut-off valve. (a) Sample of a shut-off valve

(b) ISO symbol of the shut-off valve Fig. 2.5: (a) picture of shut off valve. (b) The ISO symbol of shut off valve

2.6 Piping The pipe diameter of the air distribution system should be selected in such a way that the pressure loss from the pressurized reservoir to the consuming device ideally does not exceed approx. 10 kPa (0.1 bar).

2.6.1 Selection factors of the pipe diameter: 1. Flow rate 2. Line length 3. Permissible pressure loss 4. Operating pressure 5. Number of flow control points in the line

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.6.2 Piping layout Ring circuits (Fig. 2.6.a) are most frequently used as main lines. This method of installing pressure lines also achieves a constant supply in the case of high air consumption.

In pipe-run layout, the pipe lines must be installed in the direction (a) Ring (loop) pneumatic of flow with a gradient of 1 to 2% distribution system as shown in Fig. 2.6.b. This is particularly important in the case of branch lines. Condensate can be removed from the lines at the lowest point.

Any branching of air consumption (b) pipe-run pneumatic distribution points where lines run horizontally system should always be installed on the upper side of the main line. Fig. 2.6 : (a) shows the ring or loop distribution system. (b) shows the Shut-off valves can be used to pipe-run distribution system block sections of compressed air lines if these are not required or need to be closed down for repair or maintenance purposes.

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.7 Air service unit The air service unit shown in Fig. 2.7.a is a combination of the following: 1. Compressed air filter (with water separator) 2. Compressed air regulator 3. Compressed air lubricator (a) A picture of an air Fig. 2.7.b is the air service unit service unit without lubricator in our labs.

The main function of the service unit is to provide the pneumatic system with a well cleaned, lubricated and regulated compressed air.

(Condition the compressed air). (b) A picture of an air

service unit Fig. 2.7.a and Fig. 2.7.b Show some real air service unit. And Fig. 2.7.c shows the detailed ISO symbol of the service unit. While Fig 2.7.d shows the Simplified ISO symbol of (c) Detailed ISO symbol of the the service unit. service unit

(d) Simplified ISO symbol of the service unit Fig. 2.7

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.8 Pressure regulator (Reduce/regulate the pressure). The purpose of the regulator (Fig. 2.8.a) is to keep the operating pressure of the (a) Pressure regulator system (secondary pressure) virtually constant regardless of fluctuations in the line pressure (primary pressure) and the air consumption. Fig. 2.8.b represents the ISO symbol of the air (b) ISO symbol of the pressure regulator. regulator. Fig. 2.8: (a) pressure regulator.(b) ISO symbol of the pressure regulator.

2.9 Air lubricator (Lubricate the moving parts) Most moving parts require some type of lubrication. The efficiency of cylinders, valves and air motors can be greatly improved if they are supplied with adequate lubrication. (a) air lubricator Pneumatic components can be lubricated by using an air line lubricator (Fig. 2.9.a), a device for adding lubricating oil in aerosol form into a compressed air line. The air (b) ISO symbol of the air passing through the lubricator transports the lubricator. lubricant to air tools, cylinders or other air Fig. 2.9 operated equipment. Fig. 2.9.b represents the (a) Air lubricator. (b)ISO ISO symbol of the air lubricator. symbol of the air lubricator.

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.10 Manifold (distributor) It is used to provide multi equal pressure outlets. Fig. 2.10.a shows a pneumatic manifold (distributor). Fig. 2.10.b represents the ISO symbol of the pneumatic pressure (a) pneumatic manifold (distributor) source. Fig. 2.10.c represents the ISO symbol of T junction. (b) ISO symbol of the pressure Each output port has check valve source (Non return valve).

2.11 Tubes and fittings Fig. 2.11.a shows some types of tubes that are used in connecting pneumatic circuits.

Fig. 2.11.b shows some important (a) some types of tubes fittings such as T connections and cross connections.

(b) some types of fittings Fig. 2.11

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

2.12 Pressure gauge It used to display the actual amount of the pressure in two main units PSI and bar. 1 bar= 14.7 PSI Fig. 2.12.a shows a real pressure gauge. Fig. 2.12.b represents the ISO symbol of the pressure gauge.

(a) pneumatic pressure gauge

(b) ISO symbol of a pressure gauge

Fig. 2.12

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

5. For further reading, you can use the following links: 1- www.Fest-didactic.com 2- http://www.eng2all.com/vb/t28932.html 3- http://www.logiclab.hu/lesson.php?fe=2

6. Supplementary recourses 1- Pneumatics video from Festo. 2- FluidSIM software. 7. References 1- Festo manuals and workbook TP101 2- Festo manuals and textbook TP101

Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

Student’s notes

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Module 2: Air generation and distribution

ATM 1132 – Basic Pneumatics

Worksheet 1

QI) Draw the ISO Symbols for the following components: 1- Air compressor ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

2- Air filter ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

3- Shut off valve ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

4- Pressure gauge ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

Q2) what is the function of the following components: 1- Air tank ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

2- Manifold ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

3- Pressure regulator ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

4- Air service unit ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………

Module 2: Air generation and distribution