GB449432A - Improvements relating to apparatus for use in conveying powdered or granular material pneumatically - Google Patents

Abstract

449,432. Pneumatic conveyers. LARSEN, O. A., Woodland Avenue, Fanwood, New Jersey, U.S.A. Oct. 7, 1935, No. 27693. [Class 78 (i)] [See also Group XXXIV] In apparatus for conveying powdered or granular material pneumatically and comprising at least one container which is filled with the material through an inlet and to which compressed air is then admitted to mix with the material and drive it out through a pipe line, one or more of the valves admitting the material or connecting to air pressure or exhaust supplies is or are operated to change them from the emptying to the filling position at a predetermined interval of time after emptying has begun. Fig. 1 shows a container 1 having a feed valve 2, air exhaust valve 3, air pressure valve 4, and delivery pipe 5. Fig. 2 depicts means for operating mercury switches 2a, 3a, 4a, which control the valves 2, 3, 4, in required sequence. A cam 6 oscillates a rock-shaft 14 carrying switch-tipping arms 2b, 3b, 4b, and is rotated by a shaft 8 carrying a disc 9 set in motion by an electromagnet 10 supplied with an alternating current. A float rising with the material filling the container 1 eventually closes a switch 17 to excite the magnet 10, and the cam 6 then closes the valves 2 and 3 and opens the pressure valve 4. The speed of rotation of the disc 9 is controlled by a permanent magnet 11, which can be turned by a handle 12 to and from the disc 9, thus determining the time which the cam 6 takes to rotate and to rock the switches 2a, 3a, and 4a back again. The current controlled by the switch 4a opens the switch 17 and stops the motor. In a modification the cam 6 rotates continuously at constant speed, and in other forms an ordinary electric motor is employed or the valves 2, 3, 4 are electromagnetically operated by a clock. Specification 305,321, [Class 20 (i)], is referred to.