Abstract: An ultrasonic sensor is mounted on the splash skirt at the underflow outlet of a hydrocyclone to detect a change in the underflow discharge from the normal conical shape in which the discharge impacts upon the splash skirt to a more cylindrical shape associated with roping.

Abstract: Wear-detection sensor has a body of electrically insulating material with an opening through which a flowable substance can pass, and one or more electrical conductors surrounding the opening and adapted to undergo a discernable change in conductivity as the insulating material is worn away by the flowable substance.

Abstract: Coal spiral having a relatively short first stage helix for separating a slurry into clean coal, refuse and middlings splits, and a relatively short second stage helix for recleaning middlings split from the first stage. The first stage has only 3.25 turns, the second stage has only two turns, and a combination separator box and feed box delivers the middlings directly from the first stage to the second. The two helices are aligned coaxially, and are of opposite rotational sense to provide counter-rotation of the middlings in the two stages.

Abstract: Sieve bend for separating particles of differing size in a liquid slurry. The bend structure defines a passage having an inlet end and a discharge end, with a throat of decreasing cross sectional area at the discharge end of the passage, and a sieve screen for receiving slurry flowing from the discharge end of the passage. The throat is formed in part by a movable member, with means for adjusting the position of the movable member to vary the cross sectional area of the throat and means for temporarily moving the movable member to an open position to clear debris from the throat. The sieve screen is mounted in a housing associated with the bend structure, and the housing is vibrated in a resonant manner to dislodge material from the screen. A repulping box is positioned midway along the screen for supplying additional liquid to the slurry as it passes over the screen.

Abstract: Rotating hydrocyclone having an elongated cylinder with a side wall defining a separation chamber. A stationary inlet introduces a mixture of immiscible fluids into the chamber at high velocity in a tangential direction so that the mixture rotates about the axis of the chamber and produces a centrifugal force which tends to separate the fluids in accordance with their specific gravities. The cylinder is rotated about its axis to increase the rotation of the fluids and thereby increase the centrifugal force, with impeller vanes extending radially in an inward direction from the side wall of the cylinder near the inlet enhancing the rotation of the fluids with the cylinder. A first outlet is aligned with the axis of the cylinder for removing a fluid of lesser specific gravity from the chamber, and a second outlet is aligned tangentially with the cylinder for removing a fluid of greater specific gravity from the chamber.

Abstract: Hydrocyclone separator for separating liquids of different densities such as oil and water. The separator has an axially elongated chamber, a feed inlet for introducing liquid into the chamber at high velocity in a tangential directionso that the liquid rotates about the axis of the chamber, an overflow outlet for removing the less dense liquid from the chamber, and an underflow outlet for removing the more dense liquid from the chamber. A turbulence shield is positioned between the feed inlet and the axially disposed outlet for isolating the overflow outlet from the effects of turbulence produced by the liquid entering the chamber.

Abstract: An apparatus and method for monitoring the operation of centrifugal cyclones. Sensing means is disposed in the underflow spray discharge of a cyclone and is connected to electronic sensing circuitry adapted to produce a signal or alarm response when the cyclone ceases to operate in a normal manner. In one embodiment the apparatus and method employs a plurality of cyclones connected to receive feed material from a common manifolding means. Abnormal functioning of one cyclone of the group is immediately indicated by visual or audible alarm means and thereafter its sensing means may be disabled to permit the sensing circuitry to continue to be effective for the remaining cyclones. Delay means is incorporated in the circuitry to prevent a response when the abnormal condition is of short duration. One form of sensing means employs a probe which extends into the normal underflow discharge spray. Another form employs a paddle and switch assembly, with the paddle extending into the normal discharge spray.

Abstract: A hydrocyclone assembly suitable for use with high temperature feeds (e.g., hot petroleum liquids). The hydrocyclone body is made of ceramic material with one end being flanged and cooperating with an inlet head. These parts are clamped against a mounting plate by means including one or more spring members of the distorted washer type (e.g., Belleville washer). The mounting minimizes breakage of the hydrocyclone body when used with high temperature fluid feed. Some embodiments employ a plurality of hydrocyclones disposed within a common pressure vessel.

Abstract: Hydrocyclone apparatus having means for controlling the gravity of the discharging underflow which consists of a device formed of resilient material that is mounted directly below the apex opening of the hydrocyclone. The device provides a plurality of sectors which when relaxed extend inwardly toward the hydrocyclone axis, with the side edges of each sector in juxtaposition with adjacent sectors. When the hydrocyclone is operating the downward thrust of underflow material directly overlying the device causes the sectors to be deflected downwardly to so control the underflow as to maintain its density substantially constant irrespective of changes in the density of the slurry supplied to the inlet. Preferably the construction of the device is such that when the sectors are relaxed they are arched upwardly.

Abstract: Hydrocyclone apparatus having means for controlling the gravity of the discharging underflow. The means consists of a plurality of sectors formed of resilient material which are mounted below the apex opening of the hydrocyclone whereby when relaxed the apexes of the sectors terminate at the hydrocyclone axis and the side edges of each sector are in juxtaposition with adjacent sectors. When the hydrocyclone is in operation the discharging underflow material deflects the sectors downwardly and so controls the underflow as to maintain its density substantially constant irrespective of changes in the density of the slurry supplied to the inlet. Preferably the construction is such that an underflow shield is provided about the lower end of the hydrocyclone apex. The invention also includes the method employed by use of the apparatus.

Abstract: A method of removing fly ash particulates suspended in industrial waste gases generated from the combustion of fossil fuels in a totally enclosed scrubbing liquor circuit whereby an inert diluent such as Na.sub.2 SO.sub.4 is used for inhibiting the dissolution rates of the alkaline earth, silica, and clay mineral ingredients in the ash when the collected particulates are intermixed and suspended in weak acid solutions produced in the wet scrubbing process. The diluent may be added to the system or, if the waste gas contains significant amounts of sulfur oxides, it may be formed in situ.