Powder level measurement probe

Claim 1

In combination, a polypropylene gas phase reactor having an upper end and adapted to contain polypropylene powder therein, a rigid hollow tube means extending downwardly into said reactor from the upper end thereof, a powder probe holder mounted on the lower end of said hollow tube means and having upper and lower ends, said holder having a cylindrical recess formed in its upper end, a metal proximity sensor element in said cylindrical recess in said holder and being operatively connected to a signal device remotely from said reactor, said holder having a recessed area formed in its lower end spaced below said cylindrical recess and positioned below said sensor element, a metal plate means vertically movable mounted and pivotally movably mounted in said recessed area, and a rigid powder probe rigidly connected to said plate means and extending downwardly therefrom for contact with the powder in the reactor, said metal plate means being either vertically moved or pivotally moved towards said sensor element, to activate the same, when the powder in said reactor sufficiently moves said probe with respect to said holder, said recessed area having a circular cross-section and said plate means is disc-shaped and has a smaller diameter than said recessed area; and a support ring secured to the lower end of said holder below said plate means to maintain said plate means in said recessed area, said support ring having a central opening smaller in diameter than said plate means and said probe extending downwardly through said support ring.