Abstract: A personal dust spectrometer for aerodynamically classifying and collecting sub-fractions of inspirable dust, has an entry which has an entry efficiency approximating that of the human head during inhalation, and a cascade impactor comprising a stack of stages each having a flat element and a peripheral wall and gas exit holes. A connector enables a gas sampling pump to be attached to draw air through the entry and through the cascade impactor. A filter is desirably used to collect the smallest dust particles. All the dust entering the device is collected and is measurable.

Abstract: A process providing continuous or quasi-continuous sorption uses at least three fixed bed sorbent zones connectable in series by pipes, for the passage of a liquid phase containing a component to be sorbed. The approach of saturation of one or more of the zones is detected, e.g., using temperature sensors, and regeneration of the saturated zone or zones is initiated using hot gas. Compared to conventional sorption processes, energy savings, especially as regards energy consumed in blowing the hot gas through the fixed bed zone, are obtainable.

Abstract: A rotary cutter head for a mining machine is provided with a plurality of cutter tools mounted on an annular end component which defines the end of the cutter head remote from the mining machine. Ventilating means are provided comprising air flow guide passages having air flow inducing spray means, the air flow inlets to the guide passages being in an exposed zone in which the action of cut mineral and/or of the newly exposed working face tends to scour the inlets preventing the build up of damp, fine mineral particles and thereby tending to prevent blockage of the inlets.

Abstract: Sorbents used for drying organic liquid process streams can be regenerated by passing an organic liquid carrier solvent such as n-octanol therethrough at a temperature sufficient to dissolve water trapped in the sorbent, thus regenerating it, and subsequently cooling the organic liquid carrier solvent/water solution such that it separates out allowing recycle of the organic liquid. This method of sorbent regeneration allows the use of low grade heat for regeneration thus improving the viability of sorbent drying plant.

Abstract: A fluid supply system for a rotary cutter head of mining machines comprises a plurality of nozzles for directing air flow inducing sprays in the vicinity of the cutter head, and sensor means for sensing a preselected operational condition of the fluid supply to the nozzles and for deriving a signal indicative of the sensed preselected condition.

Abstract: Mining equipment for steering the cutting horizon of a mining machine cutter which is mounted on a ranging arm and which in use makes repeated traverses along the working face, comprises a boom urged into contact with the mine roof formed on a previous traverse of the machine. The boom is urged towards the mine roof by a ram hydraulically connected to a piston and cylinder device such that movement of the piston of the device is in accordance with that of the ram. Movement of the piston rod activates a flow control valve controlling operation of a ram controlling ranging of the arm.

Abstract: Catalysts of the ZSM-5 synthetic zeolite type can be prepared by heating a mixture of a precursor for an alumina hydrate, a precursor for silica hydrogel, an alkali metal hydroxide and water together with an organic templating agent selected from the group of carboxymethylcellulose, the condensation product of an alkanolamine and a fatty acid and cellulose hydroxyethyl ether and therafter heating the reaction product under autogeneous conditions. Unlike prior proposals ZSM-5 which is uncontaminated by other zeolites, is prepared in high yield.

Abstract: A control system of particulate material treatment plant comprising screening means which produces undersize and oversize fractions and which is controllable to vary one size fraction relatively to the other size fraction, preparation or dense medium washer means producing a relatively low ash oversize fraction and a relatively high ash oversize fraction and two storage bunkers for the undersize fraction and for the relatively low ash oversize fraction, respectively, the control system comprising sensor means for sensing the amounts of particulate material in each of the two storage bunkers and for deriving signals indicative of the sensed amounts, control means receive the derived signals and control the operation of the screening means in accordance with the received signals.

Abstract: Brake equipment for an underground mining machine, which in use traverses to and fro adjacent to a stationary rail extending along a longwall face and which includes a hydraulic haulage drive motor for hauling the machine along the longwall face, is activated to engage the stationary rail if other than a normal haulage condition of the drive motor is sensed, a control for the drive motor being moved into a neutral, machine non-traversing mode when the brake is applied.

Abstract: The rock cutting tip insert of a rock cutting tool comprises two layers, the front layer being harder than the backing or base layer by at least one hundred units on the Vickers Hardness scale.

Abstract: In controlling advance of an armoured conveyor in an underground mine, detector means detect the advance of different conveyor sections and control means control current and/or subsequent advances of the conveyor in relation to the detected advances.

Abstract: A portion of a beam of light directed towards a flow of particulate material is interrupted with an edge such that the edge casts a shadow across the material. The shadow profile is sensed and a signal indicative of the sensed shadow profile is derived and monitored as a function of flow velocity to determine the volume of flow.

Abstract: Equipment for retaining flowable material within a packhole has two connected sections defining two boundaries of the packhole. The sections comprise a base and a roof engaging assembly for engaging the mine roof. Each section has a flexible sheet connected to the base and roof assembly.

Abstract: The shoes on the goaf side of a longwall mineral mining machine comprise pivotally connected components so that the machine can hinge about these shoes during steering adjustments. Longitudinal pins connect components of goaf side shoes so that a pinion driven by the machine is maintained in engagement with a rack fixed to the track.

Abstract: A control for hydraulic equipment including a pressure fluid feed and a pressure fluid return, includes a spool valve arranged to sense the pressure of the pressure fluid in the return and to connect pressure fluid in the feed to exhaust should the sensed pressure fall below a preselected level.

Abstract: A leaky feeder coaxial cable has the inductance of the outer conductor altered by winding an extra conductor on the outer conductor or by physically forming the outer conductor so that it is unsymmetrical.