Abstract:
The invention relates to a valve (24) comprising: a body (40) defining a cavity and provided with a first opening (60) that makes it possible to feed water into the cavity, a second opening that makes it possible to discharge water from the cavity, and a third opening that makes it possible to connect the cavity (41) with a chamber; a stopper (49) that is rotatable inside the cavity, the stopper comprising a depression (77) on the outer surface (90) thereof that contributes to the definition of a passage enabling the flow of water between the first and third openings in first angular positions of the stopper and moreover enabling the flow of water between the second and third openings in second angular positions of the stopper, a sealing device that makes it possible to ensure a sealed stopping of the first opening (60) by means of the stopper in said second angular positions of the stopper; and a second sealing device that makes it possible to ensure a sealed stopping of the second opening by means of a stopper in said first angular positions of the stopper.
Abstract:
The invention concerns a method of sulphonation characterised in that it consists in contacting a nucleophile whose nucleophilic atom is a nitrogen atom with a reagent comprising by successive or simultaneous addition: a heavy sulphonyl halide (i.e. whose atomic number is not less than that of chlorine), advantageously suphonyl chloride; and an organic base both not capable of alkylation and lipid soluble; and the organic part of said sulphonyl is perfluorinated on the carbon carried by the sulphur. The invention is applicable to organic synthesis.
Abstract:
Carbocyclic/aliphatic ethers, for example anisole, quaicol, guaethol, p-methoxyphenol and ethylene dioxybenzene, are selectively prepared, in good yield, by reacting a phenolic compound, for example a phenol, hydroquinone, pyrocatechin, naphthol, or the like, with an alcohol, for example methanol, ethanol, isopropanol, ethylene glycol, etc., in gaseous phase, in the presence of a catalytically effective amount of a trivalent rare earth metal orthophosphate, for example a lanthanum, cerium or samarium orthophosphate, optionally doped with an alkali or alkaline earth metal, preferably cesium.
Abstract:
The process for cleaving the heavy by-products derived from the synthesis of alkylchlorosilanes, in particular C.sub.1 to C.sub.6 alkylchlorosilanes, more particularly methylchlorosilanes, in particular for the cleavage of alkylchlorodisilanes, in particular methylchlorodisilanes having from one to five chlorine atoms, is carried out by treatment with hydrochloric acid in the presence of a catalytic system which comprises at least one metal phosphate, preferably associated with a basic impregnation compound.The metal phosphate may in particular correspond to the formula:M(XPO.sub.4).sub.yin which M represents a metal chosen from:monovalent metals, in which case X is 2H and y=1divalent metals, in which case X is H and y=1trivalent metals, in which case X is absent and y=1tetravalent metals, in which case X is: H and y=2pentavalent metals, in which case X is 0 and y=1.
Abstract:
Lactams, in particular epsilon-caprolactam (a basic starting material for the production of nylon 6), are selectively prepared by cyclizing/reacting the corresponding aminonitriles with water, in the presence of a catalytically effective amount of a deactivation-resistant solid metal phosphate having the general formula (II):MH.sub.h (PO.sub.4).sub.n .multidot.(Imp).sub.pin which M is a divalent, trivalent, tetravalent or pentavalent element selected from among those of Groups 2a, 3b, 4b, 5b, 6b, 7b, 8, 2b, 3a, 4a and 5a of the Periodic Table, or mixture thereof, or M=0; Imp is a basic impregnating compound which comprises an alkali or alkaline earth metal, or mixture thereof, together with an electrical neutrality-ensuing counteranion therefor; n is 1, 2 or 3; h is 0, 1 or 2; and p is a number ranging from 0 to 1/3, corresponding to the molar ratio between the moiety Imp and the moiety MH.sub.h (PO.sub.4).sub.n.
Abstract:
A process for the synthesis of fluorinated organic compounds and a reagent suitable for use in the process. The process is carried out by exchange with fluorides, while preferably agitating the reaction medium with ultrasonic sound.
Abstract:
A fuel feed circuit for an aeroengine, the circuit including a high-pressure pumping system for delivering fuel at high pressure to combustion chamber injectors, the high-pressure pumping system including first and second positive displacement gear pumps driven simultaneously by the engine. A hydraulic switch member is interposed between respective outlets of the pumps, which makes it possible, in one state, to combine outlet flows from the two pumps to deliver fuel at high pressure to the combustion chamber injectors, and in another state, to discharge some or all of outlet flow from the first pump to a low-pressure feed line, an electrical control member serving to cause the hydraulic switch member to pass from one state to the other.
Abstract:
High-pressure fuel is supplied at a controlled rate to a combustion chamber via a position-controlled valve and a variable-restriction stop-and-pressurizing cut-off valve. A value representative of the real mass flow rate of fuel as delivered is calculated by a calculation unit on the basis of information representative of the pressure difference between the inlet and the outlet of the cut-off valve and of the flow section through the cut-off valve, e.g. as represented by the position X of the slide of the cut-off valve. The position-controlled valve has a variable position that is controlled by the calculation unit as a function of the difference between the calculated value representative of the real mass flow rate and a value representative of a desired mass flow rate.
Abstract:
This invention relates to a control installation (1) of a turbo-machine, comprising: a regulation device (2), a unit (4) located remotely from the device (2) by which it is controlled, a verification system (6) of the unit, comprising: an emitting/receiving antenna (8) connected to the device (2), a passive radiofrequency identification chip (12) mounted on the unit and incorporating information concerning this unit, wherein the chip (12) is designed to emit to the antenna (8) a radiofrequency signal comprising the information, in response to a radiofrequency signal sent by the antenna (8) to verify the unit, The installation is such that the antenna (8) is mounted on the unit (4).
Abstract:
A fuel-injection device in a turbomachine, comprising a high-pressure pump (10) supplying a flow control valve (16), whose outlet is connected via a pressurization and cut-off valve (20) to a fuel-injector (18) feed pipe (22), the valve (20) being connected to the inlet and to the outlet of the pump (10) in order to define two fuel pressurization thresholds, one being used to start-up and restart the turbomachine, and the other being used for operating the turbomachine as from an idle speed and for commanding an equipment with variable geometry (24).