An improved apparatus for elevating the shot used in cleaning the tubes of boilers, economisers, and other heat exchangers

摘要

995,293. Cleaning heat-exchangers. PARKER MITCHELL ENGINEERING CO. Ltd., and W. J. PARKER. Oct. 17, 1963 [Oct. 19, 1962] No. 39594/62. Heading F2N. Apparatus for cleaning the tubes of, e.g. heat-exchangers, by the impingement of shot comprises a shot collecting receptacle, a pneumatic valve controlling the inlet to said receptacle, an elevated shot receiving receptacle from which shot is discharged to the heat exchanger, this receptacle having a pneumatic discharge valve, a pipe between the foot of the shot collecting receptacle and the elevated shot receiving receptacle, the two ends of the pipe being curved, and a compressed air receiver so connected and controlled that shot which has passed through the heat-exchanger is forced from the shot collecting receptacle through the pipe to the elevated shot collecting receptacle whence it drops again into the heat-exchanger. The sequence of operations is controlled by a rotating electrical contact which completes circuits to a timer valve 23 in the air line 21, a timer valve 30, in an air line 26 from the air line 21 to a valve 25 which is operated pneumatically to control the passage of shot from the receptacle 24, and to an electromagnetic device, between the hopper 28 and the receptacle 10, which, when energized, magnetizes the shot and interrupts its flow. Periodically the timer valve 23 supplies compressed air to the receptacle 10, thus propelling shot in the receptacle through a pipe-line 12 into the elevated receptacle 24. Also the timer valve 23 supplies compressed air to a cylinder 19, causing its piston rod 18 to rise and close a valve 15, stopping the admission of shot into the receptacle 10. Before the raising of the valve 15 the shot is magnetized to prevent the valve being jammed. Immediately the shot has been elevated to the receptacle 24 the time valve 23 operates to permit the valve member 15 to drop and to cut off the passage of compressed air to the receptacle 10. The valve 25 is operated, by the timer valve 30, to permit shot to pass from the receptacle 24 into the heat exchanger 9, which is cleaned by the falling shot. The shot, after passing through the heat exchanger, lands on a vibrator 27 by which dirt is separated from the shot and drawn off by a fan 27awhile the shot is directed by a hopper 28 and shoot 29 to the receptacle 10. When shot has collected in the receptacle 10 the operating cycle may be repeated. In a modification, a smaller quantity of shot may be circulated repeatedly, in which case the hopper 28, valve 25 and electromagnetic control are no longer required. Specification 832,253 is referred to.