Method and apparatus for dispensing a fluidizable solid from a pressure vessel

Claim 2

In a process for dispensing fluidizable solid from the lower portion of a pressure vessel having a weighing device at which said solid is dispensed, a closable supply, a discharge, a source of three gas flows, one of which is applied within the vessel at a level above the solid to be fluidized at a pressure P2, a second of which is applied within said vessel in the lower portion of said vessel at a pressure P1, a third of which is applied within the discharge orifice at a pressure P3, said discharge orifice terminating in a chamber maintained under a pressure P4, the improvement which comprises determining the amount of solid dispensed at said weighing device, determining the throughflow quantity of gas flow, said throughflow quantity of gas flow being the sum of the amount of gas having a pressure P1 and the amount of gas having a pressure P3 and regulating the amount of gas and amount of solid to maintain a predetermined constant gas/solid dispensed ratio under conditions such that P1>P2>P3>P4.

Claim 3

An improvement according to claim 1 wherein the ratio of gas to solid dispensed is regulated by varying the pressure of the gas at pressure P2.

Claim 4

An improvement according to claim 2 wherein the throughflow quantity of gas is controlled in response to the throughflow quantity of solid determined to have been dispensed at said weighing device.

Claim 5

A method according to claim 1 wherein the throughflow quantity of the gas flow is controlled by varying only the gas flow at pressure P3 and maintaining the gas at pressure P1 at constant pressure.

Claim 6

A method according to claim 1, wherein the solid is in powder form and is dispensed into a metal melt.

Claim 7

A method according to claim 5, wherein a desulfurizing agent is fluidized and dispensed from said vessel at a rate between 40 and 250 kg/min, the gas/solid ratio is maintained at a value in the range from 2 to 20 N1/kg and said agent is directed into a pig iron desulphurization process through an immersion lance.

Claim 8

A method according to claim 6 wherein the desulfurizing agent is calcium carbide.

Claim 9

A method according to claim 6 wherein the solid throughflow rate is between 100 and 140 kg/min and the gas/solid ratio is between 4 and 10 N1/kg.

Claim 10

In an apparatus for dispensing a fluidizable solid from the lower portion of a pressure vessel having a weighing device, a closable supply, a discharge, a source of three gas flows, a first of which terminates within the vessel at a level above the solid in an upper portion thereof, a second of which terminates within the vessel in a lower portion thereof, a third of which terminates in said discharge, said discharge connected to a chamber, the improvement which comprises means in association with said weighing device to determine the amount of a solid dispensed into said vessel, means for determining the amount of gas throughput of the gases from second and third gas sources, and regulating means for regulating the gas and solid to maintain a constant gas/solid ratio.

Claim 11

In an apparatus for dispensing a fluidizable solid from the lower portion of a pressure vessel having a weighing device, a closable supply, a discharge, a source of three gas flows, a first of which terminates within the vessel at a level above the solid in an upper portion thereof, a second of which terminates within the vessel in a lower portion thereof, a third of which terminates in said discharge, said discharge connected to a chamber, the improvement which comprises means in association with said weighing device to determine the amount of a solid dispensed into said vessel, means for determining the amount of gas throughput of the gases from second and third gas sources, and regulating means for regulating the gas and solid to maintain a constant gas/solid ratio.

Claim 12

An improvement According to claim 9 wherein said regulating means is in operative association with a flow controlling means on the third gas source.

Claim 13

An improvement according to claim 9 wherein means are provided in association with the first gas source to regulate the pressure thereof, said means responsive to an actual value measured by weighing device for solid dispensed.

Claim 14

An improvement according to claim 7 wherein a control device is provided to regulate the quantity of the gas throughflow which device is responsive to the actual value of quantity of solid dispensed.

Claim 15

In a device for dispensing a fluidizable solid from a pressure vessel having a weighing device, said vessel having in its upper portion a closable feed aperture and a gas line having a first controllable gas pressure source of pressure P2, said vessel having in the lower portion thereof a loosening bottom and a closable discharge opening, said discharge opening having a discharge line, said discharge line discharging into a chamber of pressure P4, said vessel having in the loosening bottom and in the discharge line a second and third line discharge having a second controllable gas pressure source for a gas stream of pressure P1 and a third controllable gas pressure source at pressure P3, the improvement to maintain a gas quantity/solid quantity ratio constant which comprises a first regulating means for the solid quantity which first regulating means is operable to compare the actual value of the solid quantity measured by means of the weighing device which has a preset desired value, which first regulating means is operable to adjust the pressure of the gas stream of pressure P2 by means of said first controllable gas pressure source by synchronous adjustment thereof, a second regulating means for the gas quantity of the respective gas streams of pressures P1 and P3, which second regulating means receives the actual value of the gas quantity and the actual value of the solid quantity measured by the weighing device and, in the event of deviation from the gas quantity/solid quantity ratio to be maintained constant, adjusts the quantity by means of said second controllable gas pressure source to a constant preselected value, said device having magnitudes of pressure such that the following relationship is maintained: P1>P2>P3>P4.

Claim 16

In a device for dispensing a fluidizable solid from a pressure vessel having a weighing device, said vessel having in its upper portion a closable feed aperture and a gas line having a first controllable gas pressure source of pressure P2, said vessel having in the lower portion thereof a loosening bottom and a closable discharge opening, said discharge opening having a discharge line, said discharge line discharging into a chamber of pressure P4, said vessel having in the loosening bottom and in the discharge line a second and third line discharge having a second controllable gas pressure source for a gas stream of pressure P1 and a third controllable gas pressure source at pressure P3, the improvement to maintain a gas quantity/solid quantity ratio constant which comprises a first regulating means for the solid quantity which first regulating means is operable to compare the actual value of the solid quantity measured by means of the weighing device which has a preset desired value, which first regulating means is operable to adjust the pressure of the gas stream of pressure P2 by means of said first controllable gas pressure source by synchronous adjustment thereof, a second regulating means for the gas quantity of the respective gas streams of pressures P1 and P3, which second regulating means receives the actual value of the gas quantity and the actual value of the solid quantity measured by the weighing device and, in the event of deviation from the gas quantity/solid quantity ratio to be maintained constant, adjusts the quantity by means of said second controllable gas pressure source to a constant preselected value, said device having magnitudes of pressure such that the following relationship is maintained: P1>P2>P3>P4.

Claim 17

A device according to claim 13 wherein said second regulating means is responsive to a measuring device arranged following the second controllable gas pressure source and adjusts the gas quantity of gas at pressures P1 and P3, respectively, through control valves.

Claim 18

A device according to claim 13 wherein said second regulating means adjusts only the gas quantity of the gas stream at pressure P3 by means of a control valve.