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: A process for the removal of substantially chromium free sulfate from aqueous alkali metal solutions containing chromate and sulfate which includes mixing the solutions while having a pH of between about 2.5 and 4.5 with a calcium-containing material for a time and at a temperature sufficient to form a gypsum precipitate and separating that precipitate from the solutions; as well as a process for the production of alkali metal chlorate by electrolysis of alkali metal chloride including the removal of chromium free sulfate.

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: The invention relates to a device for filtering on a substantially horizontal plane, comprising a filter cloth (50) and a structure (51) for supporting the filter cloth capable of tilting about a horizontal axis (47) and comprising a peripheral groove (48) of uniform cross-section. The cloth is fastened to the support by a hollow tubular gasket (55) made of elastic or substantially elastic material, arranged to interact with the groove; the tubular gasket is designed to distort transversely between a free or contracted state in which it can be easily introduced into the groove into which the filter cloth has been inserted beforehand, and a distorted or dilated state in which it locks the cloth inside the groove by pressure.

Abstract: The present invention relates to a continuous process for the manufacture of potassium chlorate by coupling with a plant for the production of sodium chlorate by electrolysis, the said plant comprising a source of NaCl solution, (1), a loop for purification of the said solution (2--2', 3), an electrolysis device (4), a storage tank (5), if appropriate, and a crystallizer (6) in which the crystallization and the separation of NaClO.sub.3 crystals are preferably carried out, wherein circulating liquid is removed downstream of the said electrolysis device (4), a concentrated solution of potassium chloride is added to said liquid, precipitation (11) of the potassium chlorate is caused by any known means, the said potassium chlorate is separated off and the mother liquor from crystallization of the said potassium chlorate is recycled into the said purification loop (2--2', 3) of the sodium chlorate production plant.

Abstract: Mixer-settler apparatus of the reverse liquid flow type having at least one assembly which includes one or more mixers in series, each being fitted with stirrers and pumps, at least one settling tank in which liquids separate, and at least one submerged chute extending into the settling tank from a pump to convey the mixture of liquids from the pumps to the settling tank. The chute is constructed of enlarged dimensions which extend over a major portion of the width of the tank to facilitate a pre-settling action within the chute, and the chute extends a substantial distance into the settling tank to allow extended pre-settling time.

Abstract: The mass to be sprayed by the spray gun is stored in an airtight closed storage container. A cushion of pressurized air is generated above the level of the paint mass present in the storage container. This air cushion is fed by means of a manually operated piston pump projecting into the storage container. Accordingly, the mass to be sprayed and fed via the feed line extending to the spray gun is pressurized. Conclusively the feed line can be designed with a longer dimension, the mass to be sprayed can be more viscous and the distance in height between storage container and spray gun can be much larger.

Abstract: The invention relates to a process and a solvent for extraction of the chromates present in an aqueous solution. According to the invention, the aqueous phase is brought into contact with an organic phase comprising 2 to 10% by volume of a solvent selected from the group of tertiary or quaternary amines and 15 to 40% of a solvent selected from the group of esters of phosphoric acid in a diluent based on petroleum hydrocarbons. The invention is applicable to the production of concentrated solutions of chromates easily recyclable from an extraction of the chromates contained in an industrial solution.

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: In the illustrative embodiments of the invention disclosed, an installation for mixing and separating two non-miscible liquids includes, inter alia, an improved pump structure for raising the liquid dispersion from the mixing tank to the inlet level to the decanting tank, a low flat chute for conveying the dispersion from the mixing tank to the remote end of the decanting tank, height-controlling means for controlling the level of the interphase within the decanting tank, and provision for recycling the lighter liquid phase to the mixing tank.

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 flat spray nozzle head for a manually-operated spray gun for spraying a material, such as a color material or the like without compressed air, comprising a nozzle portion containing a nozzle body arranged therein and a connection portion for connection with a spray pump for spraying the material to be applied. An infeed element for the infeed of the sprayed material to the nozzle body is arranged within the nozzle portion. This infeed element is rotatably mounted in the connection portion. The nozzle portion is thereby rotatably connected with the connection portion.

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.