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GC 3: Wet Dedusters

GC 3: Wet Dedusters
     Part 1: Introduction
         1 INTRODUCTION
     Part 2: State of the Art
         1 CLASSIFICATION OF WET DEDUSTER TYPES
             1.1 Description of wet deduster types
                 1.1.1 Irrigated baffle dedusters
                 1.1.2 Irrigated cyclones
                 1.1.3 Irrigated fibrous dedusters
                 1.1.4 Packed bed scrubbers
                 1.1.5 Mobile bed scrubbers
                 1.1.6 Preformed spray dedusters
                 1.1.7 Plate column scrubbers
                 1.1.8 Mechanically assisted wet dedusters
                 1.1.9 Self induced spray dedusters
                 1.1.10 Venturi scrubbers
             1.2 Novel types of deduster
                 1.2.1 Condensation scrubbers
                 1.2.2 Electrostatically augmented scrubbers
                 1.2.3 Foam scrubbers
             1.3 Hybrid scrubbers
         2 ANCILLARY EQUIPMENT
             2.1 Scrubbing liquid clarification
                 2.1.1 Equipment used in clarification
             2.2 Entrainment separation
             2.3 Corrosion and erosion of scrubbers
                 2.3.1 Corrosion protection
                 2.3.2 Erosion protection
             2.4 Spray nozzles
                 2.4.1 Pressure nozzles
                 2.4.2 Gas atomising nozzles
                 2.4.3 Sonic nozzles
             2.5 Pumps
                 2.5.1 Pumps for clarified liquor recirculation.
                 2.5.2 Pumps for liquor dosing.
                 2.5.3 Pumps for sludge discharge.
                 2.5.4 Further Pumps
             2.6 Fans
                 2.6.1 Power considerations
                 2.6.2 Corrosion, erosion and fouling considerations
                 2.6.3 Fan designs
     Part 3: State of the Science
         1 INTRODUCTION
         2 THEORETICAL MODELLING CONCEPTS FOR WET DEDUSTERS
             2.1 Inertial Collection
                 2.1.1 Inertial collection by drops
                 2.1.2 Inertial collection by fibres and cylinders
                 2.1.3 Inertial collection by bubbles
                 2.1.4 Inertial collection by impacting gas jets
             2.2 Collection by interception
             2.3 Diffusional collection
                 2.3.1 Diffusional collection by drops
                 2.3.2 Diffusional collection by fibres
                 2.3.3 Diffusional collection of bubbles
             2.4 Phoretic effects
                 2.4.1 Diffusiophoresis and Stephan flow
                 2.4.2 Thermophoresis
             2.5 Theory of droplet formation
         3 MODELS FOR COLLECTION EFFICIENCY OF DEDUSTER TYPES
             3.1 Irrigated baffle dedusters
             3.2 Irrigated cyclones
             3.3 Irrigated fibrous dedusters
             3.4 Packed beds
             3.5 Mobile bed scrubbers
                 3.5.1 Moving bed scrubbers
                 3.5.2 Fluidised bed scrubbers
             3.6 Pre-formed spray dedusters
                 3.6.1 Vertical countercurrent flow
                 3.6.2 Crossflow
             3.7 Plate column scrubbers
                 3.7.1 Sieve plate columns
                 3.7.2 Impingement plate scrubbers
             3.8 Mechanically assisted wet dedusters
             3.9 Self induced spray dedusters
             3.10 Venturi scrubbers
         4 MODELS PREDICTING PRESSURE DROP IN SCRUBBER TYPES
             4.1 Irrigated baffle dedusters
             4.2 Irrigated cyclones
             4.3 Irrigated fibrous dedusters
             4.4 Packed bed scrubbers
             4.5 Mobile bed scrubbers
                 4.5.1 Moving bed scrubbers
                 4.5.2 Fluidised bed scrubbers
             4.6 Pre-formed spray dedusters
             4.7 Plate column scrubbers
             4.8 Mechanically assisted wet dedusters
             4.9 Self induced spray dedusters
             4.10 Venturi scrubber
             4.11 The Optimisation of Venturi Performance
         5 CONCLUSIONS REGARDING THE STATE OF THE SCIENCE
         6 APPENDIX - THEORETICAL MODELS FOR SCRUBBER PERFORMANCE
     Part 4: Industrial Design of Wet Dedusters
         1 INTRODUCTION
         2 SELECTION OF WET DEDUSTERS
             2.1 Advantages and disadvantages of scrubber types
             2.2 Scrubber user`s guide
             2.3 Tender evaluation
         3 SIZING OF WET DEDUSTERS
             3.1 Grade efficiency calculations
             3.2 The cut size concept
             3.3 The contacting power concept
                 3.3.1 The effect of liquid distribution on Venturi performance
                 3.3.2 Effect of liquid to gas ratio on Venturi performance
                 3.3.3 Effect of scale on scrubber performance
                 3.3.4 An anomalous effect of particle size and the use of multiple Venturis
     Part 5: Design of Venturi Scrubbers
         1 INTRODUCTION
         2 CONCEPTUAL DESIGN
             2.1 General
             2.2 Scoping design
             2.3 Design by scaling
                 2.3.1 Miniscrubber prediction of pressure drop
         3 PROCESS DESIGN
             3.1 General
             3.2 Pre- and post quencher design
             3.3 Physical and thermodynamic properties
                 3.3.1 Humid gas density
                 3.3.2 Gas viscosity
                 3.3.3 Specific and latent heats
                 3.3.4 Saturation vapour pressure and humidity
         4 MECHANICAL DESIGN
             4.1 Selection of Venturi geometry
                 4.1.1 Method of pressure drop control
                 4.1.2 Circular vs rectangular Venturis
                 4.1.3 Means of irrigation
             4.2 Sizing of Venturis for a given pressure drop
                 4.2.1 Rectangular Venturis
                 4.2.2 Sizing Procedure
             4.3 Entrainment Separation
             4.4 Materials of Construction
         5 DETAILED USE OF MINISCRUBBER

Volume III provides a comprehensive guide to wet deduster technology and science and covers virtually all of the major types of wet deduster.

Part 1 Introduction
Part 2 State of the art
Part 3 State of the science
Part 4 Industrial design of wet dedusters
Part 5 Design of Venturi scrubbers

Volume GC III   Part 1 Introduction.

This part gives a brief introduction to wet dedusting including the main advantages and disadvantages of the technology.


Volume GC III   Part 2 State of the art.

Part 2 describes the operation and uses of all of the major types of wet dedusters. Guidance on the clarification of scrubbing liquids and the use of ancillary equipment is also provided.


Volume GC III   Part 3 State of the science. 

This part is divided into three principle sections. In the first the fundamental principles and mechanisms of particle capture in wet dedusters are described. The second describes how these principles have been used to derive models for the prediction of collection efficiency for a wide variety of scrubber types. The third part deals with the prediction of pressure drop in scrubbers, again a wide variety of scrubbers are considered: including irrigated baffle, irrigated cyclone, packed bed, mobile bed, pre-formed spray, plate column, mechanically assisted, spray induced and Venturi scrubbers.


Volume GC III   Part 4 Industrial design of wet scrubbers.

In this part, basic guide-lines are given on the selection and sizing of scrubbers and a practical, rather than theoretical approach is adopted. It includes a scrubber users guide and a tender evaluation check list.


Volume GC III   Part 5 Design of Venturi scrubbers.

This part gives details of a design method for Venturi scrubbers developed as a result of an extensive research programme in this area. Simple scoping design methods are given, based on the assumption that estimates of the particle size distribution are available. Grade efficiency data is supplied as a function of pressure drop and this can be used to interpolate the design value. Such grade efficiency calculations are, however, inherently inaccurate and for installations where the maximum accuracy is required it is recommended that the SPS design of mini-scrubber be used. This unit, which may be attached to most standard sampling trains, provides an estimate of the required pressure drop to within a few percent.

The procedure is now available as an SPS Gas Cleaning software package "VENTURI", which has now been updated and rewritten for Windows as an AEA-ToolKit application.