《INERT ATMOSPHERES》求取 ⇩

1．INTRODUCTION1

2．GENERAL PRINCIPLES OF INERT GAS SYSTEMS13

Considerations in selecting the inert gas13

General features of inert atmosphere systems15

Work-space considerations16

Generalized schemes21

Other controlled atmospheres27

3．CHEMICAL PURIFICATION PROCESSES29

Gas-solid chemical reactions29

Use of calcium34

Use of manganous oxide for removal of oxygen41

Use of copper oxide for removal of hydrogen45

Other metal getters48

Catalysed reactions51

4．PHYSICAL PURIFICATION PROCESSES57

Adsorption57

Use of solid desiccants for removal of water vapour63

Use of activated charcoal for removal of organic solvents77

Purification of helium by low temperature adsorption on charcoal84

Water removal by refrigeration85

Low temperature fractional distillation86

5．PURIFICATION SYSTEMS90

Dry atmospheres90

Oxygen-free dry atmospheres92

Removal of oxygen,nitrogen and water vapour94

Molecular sieves for purification of argon at low temperatures100

Purification of helium100

6．PURIFICATION EQUIPMENT DESIGN AND ARRANGEMENT104

Introduction104

Plants for producing dry atmospheres105

Nitrogen-argon plants105

Calcium plants110

Titanium-zirconium getter plant125

Low temperature distillation plants126

Low temperature adsorption plants134

Solvent adsorption plant136

7．THE SUPPLY OF PURIFIED ATMOSPHERES TO WORK-SPACES140

Work-space considerations140

Purging of work-spaces147

Methods of maintenance of box atmosphere150

Use of ring main distribution156

Box control systems157

Separate circuits for inert gasat different purity levels162

8．LEAK-TIGHTNESS AND ITS TESTING164

The significance of leakage into work-spaces and plant164

Leak testing methods170

Leak rate measurement173

9．INSTRUMENTS FOR ESTIMATING IMPURITIES IN GASES181

Principal contaminants181

The glow discharge tube181

Measurement of oxygen189

Measurement of water vapour198

Measurement of hydrogen204

Measurement of solvent concentration204

10．OPERATIONAL AND ECONOMIC ASPECTS206

Effect of purity or type of atmosphere206

Capital and operating costs of purification plants206

Comparison of recirculation with purging commercial gas210

Efficiency factors in plant operation211

Important factors affecting costs214

Central purification plant215

11．FUTURE DEVELOPMENTS217

Inert gas requirements217

Circulation aspects217

Means of purification220

APPENDIX226

SUBJECT INDEX229