Process for discharging bulk material from a silo
AssigneeSpitzer Silo-Fahrzeugwerk KG
InventorsArtur Spitzer, Hartmut Biedert, Fritz Gramlich, deceased
Life of this patent
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Abstract
During evacuation of the contents of a silo through a pneumatic product conveyor line, the internal pressure is controlled continuously. The internal pressure rises in the event of clogging. As soon as the internal pressure exceeds a critical value, an additional volume of air is admitted into the clogged area to break up the accumulation.
Claims8
A process for evacuating pneumatically conveyable bulk material from the downwardly tapering hopper of a silo into a pneumatic conveyor line whose capacity to effectively convey material from the silo is limited by a predetermined maximum quantity of air flowing therethrough per unit of time and which communicates with a foraminous portion of the hopper, comprising the steps of continuously admitting compressed air through the foraminous portion of the hopper at a first rate per volume to loosen the material in the hopper and to effect the entry of material into and the evacuation of material through the conveyor line as long as the pressure in the silo is between a predetermined maximum and a predetermined minimum value;
- closing the conveyor line when the pressure in the silo drops below said minimum value, particularly as a result of bridging of material in the silo and/or the formation of chimneys;
- admitting into the silo compressed air at least at one location above the foraminous portion of the hopper for an interval of 0.5 to 1 second and at a second rate which is between ten and twenty times said first rate, the maximum quantity of air which is admitted into the silo on the time average basis being at most equal to said predetermined quantity;
- and opening the conveyor line when the pressure in the silo rises above said minimum value.
Dependencies are inferred from the claim text.