An apparatus and a method is disclosed for determining the crushing strength of pellets of a powdered material by compressing individual pellets between one pellet-contacting face on a force-exerting means and another pellet-contacting face on a force-measuring transducer. The transducer provides an output current at a voltage which varies in correspondence to the compressive force that is applied to a pellet during the crushing thereof. Accordingly, a pellet is first placed between the aforesaid pellet-contacting faces and the force exerting means is then driven toward the transducer at a controlled rate for compression and crushing of the pellet. Current voltage from the transducer is recorded permanently on a chart or else temporarily by means of a peak voltage remembering module in conjunction with a voltmeter having a digital read-out.
A cam plastometer in which deformation compressive forces are applied to a specimen by a cam follower engaging a cam which is rotated by a hydraulic motor. By rotating the motor at a predetermined speed, and employing a particular profile of the cam periphery, deformation forces can be applied which vary with time in a desired manner, to simulate actual conditions which occur during industrial pressing and forming operations. The plastometer also is capable of torsional testing of specimens.
An accurate method for testing the strength of nuclear fuel particles. Each particle includes an upper and lower portion, and is placed within a testing apparatus having upper and lower compression members. The upper compression member includes a depression therein which is circular and sized to receive only part of the upper portion of the particle. The lower compression member also includes a similar depression. The compression members are parallel to each other with the depressions therein being axially aligned. The fuel particle is then placed between the compression members and engaged within the depressions. The particle is then compressed between the compression members until it fractures. The amount of force needed to fracture the particle is thereafter recorded. This technique allows a broader distribution of forces and provides more accurate results compared with systems which distribute forces at singular points on the particle. 00000000000000000460000000000000000000000000000000000000000000000000000000 000098
A method and apparatus are provided for measuring the crushing strength of an abrasive, comprising particles, used in a lapping process. Embodiments include a crushing strength tester having a cup for holding the abrasive; a first motor for rotating the cup in a first direction; a piston having a face for rotatably fitting within the cup and contacting the abrasive; a second motor for rotating the piston in a second direction opposite the first direction; and a press for pressing the piston against the abrasive and crushing the particles while the first and second motors are rotating. An initial particle size distribution for the particles is determined, then the abrasive is subjected to a crushing force approximately equal to that of the lapping process using the crushing strength tester. A post-crushing particle size distribution for the particles is determined, and the initial and post-crushing particle size distributions are compared.
A pellet stack length recording switch, for use in a measurement system having a movable measuring head and a measuring device for measuring a length of a nuclear fuel pellet stack segment, includes a probe for contacting and applying a compression force to an end of the pellet stack segment, a compression spring having a predetermined compression force and cooperating with the measuring head and the probe, a pin mechanism attached to the probe, and a sensor for sensing a position of the pin mechanism and outputting a position signal for triggering a measurement by the measuring device of the length of the pellet stack segment when the compression force applied by the probe is at least equal to the predetermined compression force. The probe may include a slider block, for compressing the spring, and a probe member attached to the slider block. The pin mechanism may include a trip screw for tripping the sensor. The slider block may have a bore running therethrough for positioning the pin mechanism and the spring therein, and the measuring head may have a leg and a bore running therethrough for positioning a shaft of the pin mechanism therein. The sensor may be a Fiber optic sensor having a light beam which is broken by the pin mechanism. The switch may further include a foot switch cooperating with the sensor for triggering a measurement by the measuring device whenever the foot switch is closed and the light beam of the fiber optic sensor is broken.
Supplying method of powder paints wherein powder paint pellets are manufactured and stored as they are at the manufacture site and, when ordered, they are shipped and transported to the coater, and, at the coater site, they are stocked, and pulverized and classified into a sprayable powder upon powder coating thereby enabling to control the particle size of the powder paint while continuing the powder coating. A powder coating machine therefor pulverizes and classifies powder paint pellets into a sprayable powder at the coater site while continuing powder coating using the pulverized powder paint.
