System for acoustically detecting and/or removing jams of flowable material in a chute, and air hammer for performing the removal
First Claim
1. A method for detecting the presence of and removing jams in a chute used for transporting a flowable material including solids, the chute having an entrance for receiving a flow of the material and an exit, the chute including a jam breaking device located therein for breaking up material jams which occur in the chute, the jam breaking device initially located near the chute exit, and an acoustic detector for detecting acoustic signals associated with movement of the material through the chute, the method comprising the steps of:
- (a) periodically detecting an acoustic signal in the chute with the acoustic detector;
(b) processing the acoustic signal to determine whether material is flowing through the chute or whether material is not flowing through the chute due to a jam in the chute, and if a jam is detected;
(c) operating the jam breaking device for a fixed period of time to attempt to break up the jam;
(d) detecting and processing a new acoustic signal after the fixed period of time to determine whether the new acoustic signal indicates that the jam is still present;
(e) moving the jam breaking device a predetermined distance toward the chute entrance; and
(f) repeating steps (c), (d) and (e) as long as each new acoustic signal indicates that the jam is still present.
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Accused Products
Abstract
A method for detecting the presence of and removing jams in a chute used for transporting a flowable material includes a jam breaking device which travels within the chute. An acoustic detector detects acoustic signals associated with movement of the material through the chute and compares the acoustic signal to a stored acoustic signature representative of an unjammed chute. If a jam is detected, the jam breaking device is operated for a fixed period of time to attempt to break up the jam. After another fixed period of time, a new acoustic signal is detected and processed to determine whether the jam is still present. If so, the jam breaking device is moved a predetermined distance along the chute and operated again. These steps are repeated as long as each new acoustic signal indicates that the jam is still present. The jam breaking device is an air hammer which includes a fluid inlet, at least one fixed block of mass in the housing, a piston powered by fluid from the fluid inlet and a plurality of fluid outlet ports circumferentially spaced around the housing for expelling a stream of high pressure fluid compressed by the piston. The piston reciprocates within the housing, repeatedly striking the fixed block of mass and causing the air hammer to vibrate. The vibration and stream of air operates to pulverize material near the air hammer.
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Citations
26 Claims
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1. A method for detecting the presence of and removing jams in a chute used for transporting a flowable material including solids, the chute having an entrance for receiving a flow of the material and an exit, the chute including a jam breaking device located therein for breaking up material jams which occur in the chute, the jam breaking device initially located near the chute exit, and an acoustic detector for detecting acoustic signals associated with movement of the material through the chute, the method comprising the steps of:
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(a) periodically detecting an acoustic signal in the chute with the acoustic detector; (b) processing the acoustic signal to determine whether material is flowing through the chute or whether material is not flowing through the chute due to a jam in the chute, and if a jam is detected; (c) operating the jam breaking device for a fixed period of time to attempt to break up the jam; (d) detecting and processing a new acoustic signal after the fixed period of time to determine whether the new acoustic signal indicates that the jam is still present; (e) moving the jam breaking device a predetermined distance toward the chute entrance; and (f) repeating steps (c), (d) and (e) as long as each new acoustic signal indicates that the jam is still present. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for detecting the presence of and removing jams in a chute used for transporting a flowable material including solids, the chute having an entrance for receiving a flow of the material and an exit, the apparatus comprising:
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(a) an acoustic detector for periodically detecting at least one acoustic signal in the chute; (b) a processor for receiving and processing the detected acoustic signal by comparing the detected acoustic signal to a prestored acoustic signature, wherein a detected acoustic signal similar to the stored acoustic signature indicates that the material is flowing through the chute and thus no jam is present, and a detected acoustic signature significantly different than the stored acoustic signature indicates that material is not flowing through the chute and thus a jam is present; and (c) a jam breaking device movable between the chute entrance and chute exit for breaking up jams identified by the acoustic processor. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification