Abstract: The rotor of a cutter for removal of ore from mine faces has several external material removing bits which are mounted in holders at the exterior of the rotor, and the holders have sockets for discrete spray nozzles which discharge streams of highly pressurized water against the mine face and/or against the bits. The nozzles receive water from discrete conduits whose discharge ends are threadedly connected with the respective nozzles and whose intake ends are connected to the outlets of manifolds which are installed in the interior of the rotor. The conduits extend from the outlets of the respective manifolds and through holes which are provided therefor in the rotor. The sockets in the holders receive spherical joints which allow for changes in orientation of the nozzles with reference to the adjacent bits.

Abstract: A sectorial sprinkling device for coal mining includes, in the central portion of a cutting drum of a cutting machine, a plurality of concentric piping systems which are connected to water delivery means. An interior piping system is permanently connected to the picks of the shearing disc of the drum, but the other two piping systems open via radial ducts into sectorial chambers whose angular extent corresponds to that of the active sectors of the lateral face of the cutting drum, depending on whether the cutting drum is in the high or low cutting position.

Abstract: A vertical conduit closed at one end by a head wall and connected at its opposite end to a fluidization gas delivery means is provided with side blowing nozzles longitudinally spaced in planes. A shutter is movable inside the conduit so that the bed in which the conduit is disposed in use can be progressively brought into a state of fluidization by supplying fluidization gas to the nozzles successively and cumulatively starting from the top. The invention obviates the need for the introduction via the bottom of the fluidized bed of compressed air at a high pressure when starting up the fluidization of the bed.

Abstract: The rotor of a cutter for removal of material from a mine face has a large number of externally mounted bits each of which is adjacent to a discrete spray nozzle serving to discharge one or more streams of water at a pressure in the range of several thousand bars. The nozzles receive water from conduits which are installed in an annular chamber between the skirt of the substantially cup-shaped rotor and the adjacent end portion of the drive shaft for the rotor. Groups of conduits receive pressurized water from manifolds which are installed in the chamber and each such manifold receives pressurized water from a discrete conduit which, in turn, receives pressurized water from a distributor rotating at the discharge end of a stationary pipe in an axial bore of the shaft.

Abstract: Hearth and process for the fluidized bed treatment of a fuel consisting of solid particles. The grid (1) for conveying gaseous fluidization and/or forcing fluid to a treatment chamber (2) comprises two separately supplied circuits of channels, respectively a first circuit of channels (11) with orifices widened towards the top, for the fluidization of a particulate material, and a second circuit of tubular channels (14), opening out above widened orifices, for forcing the particulate material.

Abstract: A fluidized-bed apparatus with a heat exchanger and an additional-air blowing network. The heat exchanger comprises upright tubes extending from a lower header which is slightly inclined to the horizontal, to an upper header. The lower header consists of an internal duct which is connected to the tubes and an external duct which has blowing nozzles and is connected to an additional-air supply line in order to alter the height of the bed in which the upright tubes are immersed.

Abstract: The internal absorbent layer (9) of the casing delimits an internal volume (10) around the drill (1), which volume is divided on either side of the exhaust orifice (3) by two transverse partitions (13A, 13B) into three successive expansion chambers (11A, 11B, 11C) between the exhaust orifice (3) and the outlet opening (12) to the air outside the casing.

Abstract: A valve for the pneumatic distribution of fluidizable material comprising a main compartment with a fluidization grid and with an overflow pipe supplied with fluidizable material via a pipeline. The main compartment is put into communication by means of a passage with several auxiliary compartments with a fluidization grid and with an overflow pipe, the fluidized material leaving via any one of the overflow pipes, as desired.

Abstract: A process of remote transmission of signals issued by at least one sensor over a transmission line, wherein the power necessary to supply the sensor is transmitted by that line in the form of an alternating current signal of approximately constant intensity, and wherein the line fulfills the triple function of supplying power to that sensor, of transmitting interrogation signals from a central station to that sensor and of transmitting data signals in response to that interrogation signal from the sensor to the central station. A device for incorporating this process is also disclosed.

Abstract: Apparatus for supplying gas to a fluidization grid which has two separate supply circuits, one for compressed air and one for fluidizing air, the orifices of each circuit ending at the pyramids of the grid. The orifices of each circuit, are arranged in groups, and are connected by pipes to a stator cylinder in which a rotatable rotor tube extends. A motor is arranged to rotate the rotor tube to a number of predetermined positions. The rotor tube is connected to a supply pipework and is pierced with passage openings which are arranged upon rotation of the rotor tube to correspond to the pipes.

Abstract: A self-regulating spray nozzle is provided which includes a chamber for receiving both product to be sprayed and a driving fluid. A moveable component is provided for selectively varying the cross-sectional area of an opening provided in an output passage from the chamber in response to pressure developed within the interior of the chamber. A mechanical counter-force is exerted on the moveable component to tend to close the output passage opening of the chamber against the force of the pressure developed in the chamber, and which at least partially overcomes the force of the pressure developed within the interior of the chamber to thereby maintain the pressure drop through the output passage opening substantially constant.

Abstract: A soundproofing device for a drill which has an elongate shaft extending between a bit and a forged collar for attaching it to a pneumatic hammer comprises a sheath formed by a semi-rigid tube of plastics material adapted to surround the shaft without touching it. This sheath extends between sealed first mounting ring near the bit and second mounting ring near the hammer. These mounting ring are free to move relative to the shaft in rotation and in translation. Tests show a reduction in the noise level 5 m from the drill from 102 dBA to 89 dBA.

Abstract: The exchanger is placed in a fluid of elevated temperature and comprises tubes connected to an inlet header and to an outlet header. The exchanger comprises a plurality of panels (4) constituted by tubes (41 to 48) extending below two inlet headers and two outlet headers, to which they are connected at the upstream and downstream ends, and forming two semi-panels which are imbricated one inside the other, each semi-panel comprising a subheader tube (41 or 42) connected to an inlet header (21 or 22) and being divided into at least one tube (43,44,45 or 46, 47, 48) which is coiled into a laced configuration so that the two sub-header tubes (41 or 42) extend vertically within the envelope of said tubes having a laced configuration and they support them through cantilever supports (411, 421). This exchanger may be in particular employed in a fluidized bed apparatus or for the recovery of the heat of gas or fumes.

Abstract: A process for deodorizing polluted air, wherein the air to be deodorized is washed in a washing apparatus with an aqueous solution of hydrogen peroxide. The solution is circulated in a closed circuit while ozone is introduced either directly into the air to be treated or directly into the aqueous solution which is thus regenerated. The initial weight percentage of hydrogen peroxide in the aqueous solution is within the range of 0.5% to 10%.

Abstract: A boiler comprising a fluidized bed combustion chamber which communicates with an exchange enclosure containing water tubes heated by the combustion tubes and within which is arranged an exchange and dust removal chamber equipped with water tubes and containing a vertical internal partition dividing it into two half chambers communicating with one another. One of these half chambers communicates with the upstream part of the enclosure through an inlet orifice situated at the top part and constrains the fumes to follow a descending path along the partition, while the other communicates with the downstream part of the enclosure through an outlet orifice situated at the top part and constrains the fumes to follow an ascending path.

Abstract: A method and a device for determining explosivity rate of a gaseous medium with a detecting filament which is heated in said medium by an electric current flowing therethrough. Said detecting filament is ignited through connection to a power supply and power supplied to said filament is regulated so as to maintain constant the resistance thereof. At some successive moments value of a quantity U significant for power supplied to said filament is taken into account. An exponential curve is extrapolated from such values; parameters thereof are identified and introduced in a process function adapted to deduce therefrom an estimation of the initial explosivity rate of said gaseous medium independently of the nature of the explosive gas(es) present therein.

Abstract: The invention relates to the geometry of drill bits for jet assisted rotary drilling. According to the invention there is used a drill bit comprising platelets of small radial dimension disposed about a central burster in a discontinuous peripheral crown axially extending said drill bit, channels for supplying pressurized fluid opening from the crown close to the platelets. Said platelets are preferably separated from one another by rectilinear discharge ramps. A drill bit in accordance with this invention can be manufactured e.g. by turning or milling. It can be applied for drilling rock formations in mines, and other hard materials.

Abstract: An individual portable dust collector includes a ring of filter foam arranged to retain dust of a size in the range 5 microns to 0.5 micron. This ring is accommodated in a rotatable cup and has an exposed lateral surface located in a transverse plane. A cover surrounds the cup and has an air inlet orifice which is also located in said transverse plane. Outlet holes are provided in two diametrically opposed locations in said cover and are spaced from the transverse plane. A cowl caps the inlet orifice and contains a prefiltration block arranged to retain particles of a size greater than 5 microns.

Abstract: A process for hydrogenating coal in the liquid phase in the presence of a catalyst comprising an iron oxide obtained by decomposition of an iron compound in a flame, in particular in the flame of a torch. A co-catalyst, such as SnO.sub.2, also prepared by decomposition of a metal compound in a flame, may be added to the iron oxide.

Abstract: The present invention relates to a process for modifying the properties of a swelling coal, to an installation for carrying out the process and to a chamber for treatment by fluidization and crushing. A percussion-type crusher is installed in a fluidization chamber at about 1 meter above the zone of connection between a duct for conveying coal by pneumatic transport and the chamber. A combustion chamber produces gases for transport and fluidization, having an oxygen content of at least 10%.