System for feeding pulverulent material into a pressurized air conveyor pipeline

A system for moving pulverulent material from a line of receiving hoppers into a pressurized air conveyor pipeline conprising, in combination:

• auger transfer conveyor means beneath said line of receiving hoppers which may receive material constantly from all said hoppers;
• pressure auger conveyor means which has an effectively airtight, substantially horizontal casing, a material inlet pipe attached to the top of the casing communicating with the interior of said casing and with one end of the transfer conveyor means, a material outlet pipe attached to the bottom of the casing remote from said inlet pipe, said outlet pipe communicating with the interior of the casing and with the air conveyor pipeline through the top thereof, and a continuously operating auger conveyor in said casing to move material through said casing from said inlet pipe to said outlet pipe;
• primary valve means in said inlet pipe to control movement of material into the casing;
• secondary valve means in said outlet pipe to control movement of material from said casing into the air conveyor pipeline;
• means for varying the air pressure in said casing between a low pressure close to atmospheric and pipeline pressure;
• and control means producing a continuous cycle in which the primary valve means is first opened while the secondary valve means is closed to feed material from said auger transfer conveyor means into the casing of the pressure auger conveyor means at said low pressure until said casing is effectively full, and in which the primary valve means is then closed, the pressure in said casing is raised to pipeline pressure, and the secondary valve means is then opened to permit the auger conveyor in the casing to empty said casing while the auger transfer conveyor means moves material toward the material inlet pipe.

Pressure mechanical conveyor means for a system for moving pulverulent material from a receiving hopper into a pressurized air conveyor pipeline, said pressure mechanical conveyor means comprising, in combination:

• an effectively airtight casing;
• first and second material inlets in the top of said casing near opposite ends thereof, each of said inlets being adapted for attachment to a material transfer conveyor to receive material therefrom;
• a material outlet in the bottom of the casing between said inlets, said outlet being adapted for attachment to the pressurized air conveyor pipeline to deliver material thereto;
• a mechanical conveyor in the casing to move material simultaneously from both said inlets toward said outlet;
• and gas receiving and venting connections on said casing adapting said casing to have its internal pressure varied between a lower pressure close to atmospheric and a higher pipeline pressure.

A system for moving pulverulent material from two receiving hoppers into a pressurized air conveyor pipeline comprising, in combination:

• pressure mechanical conveyor means which has an effectively airtight casing, two material inlets in the top of said casing adjacent its ends, a material outlet in the bottom of the casing between said inlets, said outlet communicating with the top of the air conveyor pipeline, and a mechanical conveyor in said casing to move material from both said inlets toward said outlet simultaneously;
• first and second transfer conveyor means each operatively connected to the bottom of one of the two receiving hoppers and to one of the two material inlets of the pressure mechanical conveyor casing, said transfer conveyor means including a material confining pipe and a mechanical conveyor in said pipe;
• primary valve means to control movement of material through said inlets;
• secondary valves means to control movement of material through said outlet;
• means for varying the air pressure in said casing between a lower pressure chose to atmospheric and higher pipeline pressure, said means including a pressure air line which communicates with the casing at each of said inlets, air vent lines which connect both inlets with the material receiving hopper and an air vent line which connects an area of the casing immediately adjacent the outlet with the material receiving hopper;
• and control means including a valve in each of said pressure lines and in each of said air vent lines, and means for closing said pressure line valves and said vent line valves alternately so said casing is filled at said lower pressure and emptied at said higher pressure in a continuous cycle.

In a system which includes a line of precipitator receiving hoppers which are filled by material that drops from a gas stream moving along said line so that the hoppers receive progressively less material from the most upstream hopper to the most downstream hopper, means for moving pulverulent material from said hoppers into a pressurized air conveyor pipeline comprising, in combination:

• transfer conveyor means extending longitudinally beneath said line of hoppers and operatively connected to the bottoms of all said hoppers, said transfer conveyor means including a material confining pipe and a mechanical conveyor in said pipe;
• pressure mechanical conveyor means which has an effectively airtight casing, a material inlet in the top of said casing which is operatively connected with said material confining pipe at the end portion thereof that is nearest to the most upstream hopper, a material outlet in the bottom of the casing remote from said inlet, said outlet communicating with the top of the air conveyor pipeline, and a mechanical conveyor in said casing to move material from said inlet toward said outlet;
• primary valve means to control movement of material through said inlet;
• secondary valve means to control movement of material through said outlet;
• means for varying the air pressure in said casing between a lower pressure close to atmospheric and higher pipeline pressure;
• and control means for filling said casing at said lower pressure and emptying said casing at said higher pressure in a continuous cycle.