Metering system and use thereof

A valve assembly comprising:

• (a) a valve body defining a valve chamber, an inlet port and a discharge port, wherein the inlet port and discharge port communicate with the valve chamber;
• and
• (b) a valve member in the valve chamber, the valve member comprising a passage having a first passage section and a second passage section separated by a filter having an inlet surface proximate to the inlet port and a discharge surface proximate to the discharge port, wherein the passage communicates with the inlet port and discharge port, and
• wherein the valve member is moveable to alternately juxtapose the inlet port and either the first passage section or the second passage section.

A method of feeding a particulate material, the method comprising:

• (a) providing a first amount of the particulate material in a fluid to a particulate material metering system, the particulate material metering system comprising:
• (1) a valve body defining a valve chamber, an inlet port and a discharge port, wherein the inlet port and discharge port communicate with the valve chamber;
• and
• (2) a valve member in the valve chamber, the valve member comprising a passage having a first passage section and a second passage section separated by a filter having an inlet surface proximate to the inlet port and a discharge surface proximate to the discharge port, wherein the passage communicates with the inlet port and discharge port,
• (b) retaining the first amount of the particulate material in the first passage section and discharging the fluid through the filter through the second passage section and the discharge port;
• (c) juxtaposing the valve member to place the second passage proximate to and communicating with the inlet port;
• and
• (d) providing either
• (1) a second amount of the particulate material in the fluid to the inlet port and the second passage section and retaining the second amount of the particulate material in the second passage section on the filter and discharging the fluid through the filter which flushes the first amount of particulate material through the first passage section and the discharge port, or
• (2) a quantity of the fluid to the inlet port and the second passage section that discharges through the filter which flushes the particulate material through the first passage section and the discharge port.

A method of making a polyolefin by feeding an olefin and a catalyst to a polyolefin reactor, the method comprising:

• (a) providing a first amount of the catalyst in a fluid to a catalyst metering system, the catalyst metering system comprising:
• (1) a valve body comprising a valve chamber, an inlet port and a discharge port, wherein the inlet port and discharge port communicate with the valve chamber;
• and
• (2) a valve member in the valve chamber, the valve member comprising a passage having a first passage section and a second passage section separated by a filter having an inlet surface proximate to the inlet port and a discharge surface proximate to the discharge port, wherein the passage communicates with the inlet port and discharge port,
• (b) retaining the first amount of catalyst in the first passage section on the inlet surface of the filter and discharging the fluid through the filter, the second passage section and the discharge port;
• (c) juxtaposing the valve member to place the second passage section proximate to and communicating with the inlet port;
• d) providing either
• (1) a second amount of the catalyst in the fluid to the inlet port and the second passage section and retaining the second amount of the catalyst in the second passage section and discharging the fluid through the filter which flushes the first amount of catalyst through the first passage section and the discharge port, or
• (2) a quantity of the fluid to the inlet port and the second passage section that discharges through the filter which flushes the catalyst through the first passage section and the discharge port into a polyolefin reactor;
• and
• (e) contacting the catalyst and the olefin in the reactor under conditions sufficient to form the polyolefin.