2. Storage, transport and milling of particulate solid Flashcards
For what type of materials is screw conveyor used?
Granular, slurry, pasty materials (rotating part needs special coating), loose materials
How does disk feeder work?
As the disk rotates, material from the bin falls onto the disk and is transported to the edge of the disk by centrifugal force. Then the material is being discharged
How hydraulic transport work in order to move substances? What is it used mostly for?
It is moving solid materials (such as powders, granules, or larger particles) suspended in a liquid, typically water, through a pipeline or channel. Also there has to be enough pressure to move the slurry from the pipes. Velocity- high enough.
Its used for self-igniting materials and suspensions.
Hydraulic transport capacity (kg/h) What does it depend on?
pipe cross section, material flow rate, specific weigth of material, dispersion.
Pneumatic transport. How does it work?
Air/gas is used for moving.
What are the differences between negative conveying and positive conveying?
Negative conveying-vacuum conveying. here vacuum pump creates a suction (negative pressure). Material pulled through the pipeline by the suction force created by the vacuum. Vacuum systems prevent dust here.
Positive conveying (pressure)
Uses pressurized air to push material through the pipeline. Potential for dust.
Why dust is wrong in conveyers?
If dust particles are dispersed in the air at a high enough concentration and an ignition source is present (such as static electricity, heat, or a spark), a dust explosion can occur. Also inhalation (health risks).
Why is it important to create non-conductive environment in material transport systems?
When materials flow through pipelines in pneumatic or mechanical conveying systems, friction between the particles and the surfaces of pipes or other system components can generate static electricity.If this static charge accumulates, it can discharge in the form of a spark, which is especially dangerous in environments where flammable gases, combustible dust, or volatile chemicals are present. A small spark can ignite dust or gases, leading to fires or explosions. If this static charge accumulates, it can discharge in the form of a spark, which is especially dangerous in environments where flammable gases, combustible dust, or volatile chemicals are present.
