Disclosed is a valve for use in particulate material processing. The valve has a rotatable closure member having a convex sealing surface and a resilient sealing ring moveable between a first configuration in which the sealing ring forms a seal around a circumference of the convex sealing surface; and a second position in which a circumferential gap is defined between the convex sealing surface and the sealing ring. The valve body defines a fluid-directing surface extending around the fluid passage between the inlet and the sealing ring to define an annular clearance which tapers towards the sealing ring and becomes narrower than the annular gap. When there is a pressure drop across the valve and before the closure member is moved to fully open the valve, material flowing through the valve experiences a dynamic pressure rise towards the circumferential gap, decreasing flow velocity and wear.

Disclosed is a valve for use in particulate material processing. The valve has a rotatable closure member having a convex sealing surface and a resilient sealing ring moveable between a first configuration in which the sealing ring forms a seal around a circumference of the convex sealing surface; and a second position in which a circumferential gap is defined between the convex sealing surface and the sealing ring. The valve body defines a fluid-directing surface extending around the fluid passage between the inlet and the sealing ring to define an annular clearance which tapers towards the sealing ring and becomes narrower than the annular gap. When there is a pressure drop across the valve and before the closure member is moved to fully open the valve, material flowing through the valve experiences a dynamic pressure rise towards the circumferential gap, decreasing flow velocity and wear.

A pressurized tank is provided in which no air flows back from a piping for conveying powder to the pressurized tank. A pressurized tank (A) is used for a device (B) for intermittently feeding a predetermined amount of powder to a piping (7) for conveying the powder when the powder is conveyed in a plug flow through the piping (7) by means of compressed air. The tank (A) has a first pressurized room (6) that is a pressure vessel and that has a funnel-shaped upper partition (3) that has an opening and a funnel-shaped lower partition (4) that also has an opening, a first check valve (9) that is provided beneath the opening of the upper partition (3) of the first pressurized room (6) and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the upper partition (3), a second check valve (10) that is provided beneath the opening of the lower partition (4) of the first pressurized room (6) and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the lower partition (4), and an elastic body (24) to upwardly bias the second check valve (10).

A pressurized tank is provided in which no air flows back from a piping for conveying powder to the pressurized tank. A pressurized tank (A) is used for a device (B) for intermittently feeding a predetermined amount of powder to a piping (7) for conveying the powder when the powder is conveyed in a plug flow through the piping (7) by means of compressed air. The tank (A) has a first pressurized room (6) that is a pressure vessel and that has a funnel-shaped upper partition (3) that has an opening and a funnel-shaped lower partition (4) that also has an opening, a first check valve (9) that is provided beneath the opening of the upper partition (3) of the first pressurized room (6) and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the upper partition (3), a second check valve (10) that is provided beneath the opening of the lower partition (4) of the first pressurized room (6) and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the lower partition (4), and an elastic body (24) to upwardly bias the second check valve (10).