Mechanical Design of Process Equipment

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13.1. INTRODUCTION

Mechanical design of

chemical plant

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pressure vessels

storage tanks

heat-exchanger

particular interest to chemical engineers developing and

specifying the basic design information

will be responsible for

1. Vessel function.

2. Process materials and services.

3. Operating and design temperature and pressure.

4. Materials of construction.

5. Vessel dimensions and orientation.

6. Type of vessel heads to be used.

7. Openings and connections required.

8. Specification of heating and cooling jackets or coils.

9. Type of agitator.

10. Specification of internal fittings.data sheet for pressure vessel

design

13.1.1. Classification of pressure vessels

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Pressure vessels are sub-divided into two classes depending on the ratio of the wall thickness to vessel diameter: thin-walled vessels, with a thickness ratio of less than 1 : 10; and thick-walled vessels, above this ratio

If the wall is thin, the radial stress 3 will be small and can be neglected in comparison with the other stresses, and the longitudinal and circumferential stresses 1 and 2 can be taken as constant over the wall thickness.

In a thick wall, the magnitude of the radial stress will be significant, and the circumferential stress will vary across the wall.

Piping & Instrumentation Diagram

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Data sheet for pressure vessel

design

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to check the feasibility of a proposed equipment design

to estimate the vessel cost for an economic analysis

to determine the vessel’s general proportions and weight for plant layout purposes

Sufficient for the chemical engineer

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13.2. PRESSURE VESSEL CODES AND STANDARDS

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British Standard PD 5500 European Standard EN 13445 American Society of Mechanical Engineers code Section VIII (the ASME code)

Design

materials of construction

fabrication (manufacture and workmanship)

inspection and testing

The current (2003) edition of PD 5500 covers vessels fabricated in carbon and alloy steels, and aluminium

The design of vessels constructed from reinforced plastics is covered by BS 4994

The ASME code covers steels, non-ferrous metals, and fibre-reinforced plastics

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TERIMA KASIH