Print this page Pneumatic Conveying Systems
A. Bhatia, B.E.
Course Outline
From pebble lime to peanuts, from coal to baby powder - and everything in between – pneumatic conveying has long been a popular choice for moving bulk materials, either from storage facilities to a process unit, or between process units. In reference to this, there are two types of pneumatic operations, the dilute phase and the dense phase.
Selecting the correct pneumatic conveying regime for your requirements is a vital decision for a successfully designed system. This 5 -hour course presents an overview of pneumatic material handling system and summarizes the main hardware and technology for efficient conveying.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
At the conclusion of this course, the reader will:
- Understand the advantages of pneumatic conveying systems over mechanical conveying;
- Understand the characteristics and limitations of dilute phase, dense phase and air activated gravity conveying;
- Understand the fundamental design differences of dilute phase and dense phase conveying;
- Understand the various types and applications of dilute phase conveying systems – positive pressure, negative pressure and combination systems;
- Understand the design approach and typical specifications of positive pressure, vacuum and combination pull-push dilute phase conveying systems;
- Understand the system design objectives for new projects and the expansion/retrofit projects;
- Understand the factors influencing the performance of pneumatic conveying systems and learn how conveying rates are influenced by type of materials and affected by distances;
- Understand the terms “saltation” and “choking” as applicable to pneumatic systems;
- Learn by example – the methodology for selection of prime mover for a dilute phase pneumatic conveying systems;
- Gain understanding of pneumatic conveying system components such as fans, airlocks, separators, piping and filters;
- Understand the material intake and discharge methods;
- Understand the three key reasons to use dense phase systems;
- Learn the applications of the different modes of dense phase conveying including fluidized dense phase, low velocity slug flow, low velocity plug flow, extrusion flow and bypass conveying;
- Learn top ten tips for the design of dilute and dense phase conveying systems; and
- Learn how to estimate pressure drop in dilute phase conveying system.
Intended Audience
Process/production personnel, mechanical and chemical engineers, operation and maintenance engineers in the following industries will benefit from the information provided in this course: chemical, petrochemical, agro-chemical, and specialty chemical, biotechnology, pharmaceuticals and cosmetics, food processing, mining/mineral processing, plastics processing, bulk storage, pulp and paper.
Benefit to Attendees
It will help you determine the current limitations of your existing system and guide you through the process towards finding the best solution, including:
- Improving the existing system
- Designing a new system.
Course Introduction
Pneumatic conveying specifically refers to a process by which solids are moved by a gas stream through pipes, which can either be horizontal or vertical. The solids themselves may be suspended in the gas, if they are small particles, or the pressure of the gas stream may just force them along, if they are present in larger molecules. In fact, part of the reason why pneumatic conveying is popular is that it works for a large range of sizes of solids, from fine powder and pellets to much larger particles.
There are broadly two types of pneumatic conveying systems, 1) dilute phase and 2) dense phase pneumatic conveying. Dilute refers to solids that can be conveyed in suspension, while dense refers to those which are bigger. The final distinction lies within the properties of the solids themselves.
This course describes the main hardware and technology considerations for efficient conveying.
Course Content
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Course Summary
Essentially, the two most distinct categories of pneumatic conveying can be described as either low pressure (dilute phase) or high pressure (dense phase) systems. The choice between dilute and dense phase operation is typically dependent on the material properties. In general, bulk materials with poor air retention capabilities are less suited for dense phase system and granular products with narrow particle size distribution have good air permeability and are well suited for dense phase conveying.
In addition, dense phase operation (with its relatively low velocities) is usually preferable if the conveyed material degrades easily or is highly abrasive. Dense phase conveying can handle high throughputs over long distances while requiring smaller line sizes than either dilute-phase or vacuum conveying. A drawback of the dense phase option is that dense-phase conveying is essentially a batch process, which is less convenient for most chemical process operations than is the continuous mode used by dilute phase and vacuum systems.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
