Expert ForumsPowder Handling

Topic: Re: Can you offer short-distance pneumatic conveying solutions?

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There are several options for short-distance pneumatic conveying, especially for the size of solids described.  The most common is a vacuum system.  A gas mover (fan, vacuum pump, PD blower) provides suction with a T line before the inlet (one connection goes to atmosphere or filtered air; the others connect the piping from the cyclone to the gas mover inlet).  A filter prevents dust from getting in the gas mover and is optional for a fan (assuming regulations permit).  The solids receiver is a cyclone with a flapper discharge valve (there are many manufacture of this type of cyclone).  The flapper closes on vacuum and opens when the vacuum is removed and the weight of the solids cause it to open (it is spring loaded).  The last component is the convey line and can be a hose or a hard-piped line.  Normally a timer is used to control the operation.  When the T valve is open to atmosphere, the pressure at the cyclone outlet is zero gage pressure and no solids flow from the pickup point.  With suction applied (T-valve to atmosphere is closed), solids flow to the cyclone.  A timer can be used to limit the size of the batch that is transferred.  The spring on the cyclone can be used to limit the batch size, but this is less efficient and can cause carry-over to the filter. An eductor can be used, but may cause a lot of dust in the work area without a receiver and filter.