Abstract: A process and installation for the cryogenic purification of impure hydrogen, of the type in which impure hydrogen is cooled under a low pressure PO to a temperature sufficiently low to condense a predetermined proportion of the impurities, by heat exchange in a thermal heat exchange line (3) with purified hydrogen and with a residual fraction containing the expanded preliminarily condensed impurities (in 11, 12) to a low pressure P1. The remaining cold is supplied by the expansion of purified hydrogen in a turbine (8) with gas bearings and the expanded hydrogen is added to the light impurities expanded at the cold end of the heat exchange line. The turbine (8) is supplied with the gas leaving its bearings (17), after cooling of hydrogen at the labyrinthine seal (18) of the turbine is withdrawn under a pressure slightly less than the interstitial pressure Pi which prevails between the rotor (14) and the stator (16) of this turbine.

Abstract: A new ultrasonic transmission imaging apparatus is disclosed, which uses a new imaging method providing image focusing capability. The apparatus comprises an ultrasonic emitter producing substantially continuous coherent ultrasonic waves toward an object to be inspected. The apparatus further comprises an ultrasonic detectors array comprising a plurality of ultrasonic detectors receiving the object traversing ultrasonic waves to produce a plurality of series of electrical signals coming from the ultrasonic detectors, the electrical signals characterizing transmission of the ultrasonic waves through the object and being associated with series of image elements. The apparatus further comprises a signal vector components detector detecting signal vector components for each of the electrical signals. The apparatus further comprises a computer for controlling the apparatus and for receiving pairs of first and second signal vector component digital signals coming from the signal vector components detector.

Abstract: Process and apparatus for the purification of hydrogen by cryogenic treatment of a gas containing also nitrogen oxides and unsaturated hydrocarbons as two types of constituents which react together in an undesirable fashion when cooling achieves an intermediate temperature higher than the low temperature of the treatment. The process comprises cooling the gas to a first temperature higher than that intermediate temperature; eliminating from the gas one of the two types of constituents at this first temperature; and continuing the cooling of the gas to the low temperature. The elimination of one type of component is effected by washing the gas with a liquid adapted to dissolve it. This liquid contains at least one saturated hydrocarbon and is obtained by a partial condensation of an auxiliary gas which contains at least one of hydrogen and a heavy constituent whose value can be increased.

Abstract: Current pulses are conducted through an inductance by means of a switching transistor. The switching transistor is controlled by means of an amplifier and pulse shaper circuit in such a manner that a constant average direct current flows in a closed loop comprising said inductance and a recovery diode, resulting in a regulated, constant output voltage across two Zener diodes. This allows a particularly effective operation with relatively low power losses in said switching transistor as compared to the utility current at the output terminals, and the circuit operates reliably in a wide range of operating voltages.

Abstract: Process for the purification of a gas containing selectively adsorbable impurities, of the type using several adsorbers with, for each adsorber, a cycle comprising the following operating phases which are offset from one adsorber to the next timewise by a fraction 1/n of the duration of the cycle in which n is the number of adsorbers, the cycle comprising substantially isobaric production at a high pressure of the cycle, this production comprising the admission of impure gas to be treated into an adsorber at a first end of the adsorber with circulation of this gas in the adsorber and simultaneous withdrawal from a second end of the adsorber of purified gas, the direction of flow in the adsorber from the first end to the second end being cocurrent and the opposite direction being countercurrent; regeneration of the adsorber comprising a decompression of the adsorber to a low pressure of the cycle, this decompression comprising at least one stage in which a residual gas is withdrawn countercurrent from the adso

Abstract: A treatment device and a method for simultaneously applying vibrations and percussion forces to a predetermined area of a patient's body adjacent the lungs of the patient. The device comprises a housing having a handle portion. A clapping head is disposed exteriorly of the housing and connected to a reciprocable element which is imparted a set low frequency reciprocation movement by a low frequency generation device to impart a clapping action to the head. The head has a contact surface for engagement with the predetermined area of the patient's body. An independent vibrator element is also provided and has a body engaging member which is disposed in relation to the clapping head and connected to a vibration generating device capable of vibrating the vibrator element at a higher predetermined frequency than the reciprocation movement of the clapping head. Preferably, the clapping frequency is in the range of from 0.5 Hz to 2 Hz and the vibration frequency is in the range of from 40 Hz to 70 Hz.

Abstract: A light component of the compressed mixture is separated by permeation. The remaining heavy fraction is condensed with water, sub-cooled and expanded. The light component, cooled at the same temperature, is added to the sub-cooled condensate, and the whole is vaporized under low pressure to produce the required refrigeration.

Abstract: Methanol is catalytically cracked (at 4) then the essential portion of the components other than CO is removed by washing with water (at 5), selective adsorption (at 7) and permeation (at 8). The process and apparatus has application to the production of moderate quantity of carbon monoxide.

Abstract: The invention relates to a brake booster of the type for motor vehicles comprising a casing and a diaphragm which divides the interior of the casing (5) sealingly into a front chamber and a rear chamber, a hollow piston (10) movable in the casing, an input member (14, 16) intended to be connected to a brake pedal (18), an output assembly (20, 26) intended to be connected to a piston of a master cylinder, and a reaction disk (32) made of a deformable material and arranged between the hollow piston (10) and the output assembly (20, 26), in order to receive the output force of the booster when it is put into operation, the output force causing a first deformation of the reaction disk (32), this deformation tending to push back the input member (14, 16). According to the invention, the output assembly (20, 26) is formed in two parts, one movable relative to the other counter to a spring means (36), in order to act on a reduced surface of the reaction disk ( 32).

Abstract: The gas to be treated is cooled and partly condensed in two steps (3-4, 5-6), and the condensed fractions are distilled in a column (9). A part of the condensed liquid at the top of the column is subcooled in the second exchanger 5, expanded, and vaporized in counter-current to the gas to be treated. This permits the obtainment of cooling temperatures on the order of -80.degree. C. by means of a refrigerating unit (13, 20) operating at a temperature on the order of -30.degree. to -40.degree. C. Application to the recovery of a mixture of propane, butane and pentane from a petroleum refinery residual gas.

Abstract: This process is of the type in which there is compressed in at least two stages 2, 6 a mixture of cooling fluids composed of constituents of different volatilities and in which, after the last stage 6 and after at least an intermediate compression stage 2, the mixture is partly condensed, the condensed fractions are expanded and vaporized in heat exchange with the fluid to be cooled before being compressed again. According to the invention, at least one of the condensation stages is carried out by sending to a distillation column 7 the mixture issuing from the corresponding stage of the compressor. This enables the thermodynamic irreversibility to be decreased and consequently permits a reduction of the specific cooling energy.

Abstract: The starting gas is partly condensed in an exchanger 1. The refrigerating power is supplied, on one hand, by the free expansion of the liquid fraction and, on the other hand, by expansion in a gas-bearing turbine of the vapor fraction rich in hydrogen. A small part of this vapor fraction is used to feed auxiliary gases to the turbine, then is cooled in the exchanger 1, expanded and injected into the expanded liquid fraction so as to obtain a sufficiently low bubble point. The invention is useful in recovering hydrogen from purge gases of apparatus for ammonia synthesis, the purge gases being composed of hydrogen and less volatile components.

Abstract: Method and apparatus for liquefying a gas such as natural gas, utilizing at least one cycle fluid comprising a refrigerating mixture, with at least one first principal cycle fluid under a low pressure in countercurrent heat exchange with the gas which is to be liquefied and with at least one second principal cycle fluid under a high pressure. At least one secondary cycle fluid is obtained by withdrawing a portion in liquid phase from the refrigerating mixture at the high pressure and is expanded to the low pressure and is then added to the first principal cycle fluid.

Abstract: This invention relates to the reheating of a cold cryogenic fluid by heat exchange with a warm liquid, commonly water. The cold cryogenic fluid first flows into a descending tube and then into a rising tube whereas the water trickles along the tubes and from an upper supply, as far as a base manifold. The invention is particularly applicable to the reheating and revaporization of liquified natural gas.