Knowledge for the Sulphuric Acid Industry
Sulphuric Acid on the Web
Introduction
General
Equipment Suppliers
Contractor
Instrumentation
Industry News
Maintenance
Acid
Traders
Organizations
Fabricators
Conferences
Used
Plants
Intellectual
Propoerty
Acid
Plant Database
Market
Information
Library
Technical Manual
Introduction
General
Definitions
Instrumentation
Plant Safety
Metallurgial
Processes
Metallurgical
Sulphur Burning
Acid Regeneration
Lead Chamber
Technology
Gas Cleaning
Contact
Strong Acid
Acid Storage
Loading/Unloading
Transportation
Sulphur
Systems
Liquid SO2
Boiler Feed Water
Steam Systems
Cooling Water
Effluent Treatment
Utilities
Construction
Maintenance
Inspection
Analytical Procedures
Materials of Construction
Corrosion
Properties
Vendor Data
DKL Engineering, Inc.
Handbook of Sulphuric Acid Manufacturing
Order
Form
Preface
Contents
Feedback
Sulphuric Acid
Decolourization
Order Form
Preface
Table of Contents
Process Engineering Data Sheets - PEDS
Order
Form
Table of Contents
Introduction
Bibliography of Sulphuric Acid Technology
Order Form
Preface
Contents
Materials of Construction - Mesh Pads
The small wire diameter typically used in the construction of a mesh pad make corrosion resistance an important factor in selecting the matierla of construction for a mesh pad. A corrosion rate of 0.005 inches per year is not serious where the material is quite thick such as in a vessel wall. However, mesh pad wire diameters are typically 0.011 inches in diameter and a corrosion rate of 0.005 inches per year will destroy a mesh pad in 2 years or less.
Materials with superior corrosion resistance generally come at a premium cost. Thus the initial capital cost of a pad must be compared to the expected life and subsequent replacement costs.
Where a suitable metal is not available for the service, a non-metallic material may be suitable. Non-metallics often offered superior resistance to metals but are limited by high operating or upset temperatures.
Item | Material | Comments |
Mesh | 316L SS | Most economical material but shortest life |
Alloy 20 | Upgrade from 316L SS with improved life | |
LEWMET® | Estimated to last 3 to 5 times
longer than alloy 20 mesh pads. For use in 93% H2SO4 service. |
|
SX® | Estimated to last 3 to 5 times
longer than alloy 20 mesh pads. For use in 98% H2SO4 service. |
|
Alloy 66 | ||
PTFE | Mesh can be solely PTFE or PTFE can be co-knitted with one of the metal wires to form a composite pad. | |
ETFE | Material of consturction for Kimre, Inc. B-GON® mist eliminators | |
Support Grids | 316L SS | Most economical material but shortest life |
Alloy 20 | Upgrade from 316L SS with improved life | |
Tie Down Wires | Alloy 20 |
Non-metallic materials are limited by operating temperature. One disadvantage of non-metallic materials is the risk of damage to the pad if hot gases were to backflow into the tower.