GAS-COOLING SYSTEM AND ITS USES

This invention relates to improvements and variant embodi- FIG 1 fa diagrammatic sectional view showing the main ments of systems of the kind disclosed in U.S. Pat. No. constituent elements of the system according to the mvenUon; 3,541,801 and which are adapted to subdivide a compressed 5 F1GS -f lllustf v lant embodiments of a congas flow at a certain temperature into a first flow of lower tern- struct.onal detail of the system shown m FIG. 1; perature and a second flow of higher temperature, the latter FIGS - are diagrammatic sectional views of four vanant flow possibly being low or even zero, so that the systems embodiments using an aerodynam.c bistable control system; behave in effect like gas-cooling apparatuses. One of the main F G 9. san analogous view of a vanant embodiment; features of the systems to which the afore-mentioned patent 10 FIG10IS a cross-section, taken along the line X-X in FIG.

relates is that they operate on pulsating gas flows, using the ___ .

physical phenomena deriving therefrom; the pulsating flows FIG 1 -""ates grammatically an unproved expansion can be produced from continuous initial flows by means of and coolm8 system according to the invention, taken in sec-suitable control elements, inter alia aerodynamic bistables, tionalongtheluieXI-XIinFIG.12; operating by the periodic deflection of the initial continuous 1 FIG 12 a sectlonal vlew taken alon8the hne XU- m gas flow and the conversion thereof into pulsating flows, such 9.J i-. ... , , ...

bistables forming genuine fluid switches and if necessary FIG- 13 ls a Partial vlew analogous to FIG. 11, showing the dispensing with all mechanical moving members, as disclosed chamber to an enlarged scale; in Kadosch el al U.S. Pat. No. 2,825,204. FIGS- 1416 diagrammatically illustrate three methods of According to the present invention a pressurized gas jet 20 using the invention for the removal of gasoline, and delivered by an injector across a break in continuity is col- FIG- I7isa Clrcult diagram of an apparatus for the removal lected in one or more tubes whose inlet aperture faces the in- of gasoline comprising the system illustrated in FIGS. 11 and jector and in which the collected gas is pulsated and heated by compressive wave phenomena to a temperature higher than The system ""strated in FIG. 1 comprises a pressurized gas that of the original jet, while impellent gas, removed at the 25 source 1 which is shown as a reservoir in the drawing, but level of the break in continuity via a suitable by-pass, is ex- could be anything else, for instance a compressor. After leavpanded in relation to the original jet and brought to a lower in8 M adjustable expansion valve 2, the continuous gas flow is temperature than the latter. converted by a rotary needle valve 3 or some other suitable Preferably, the or each oscillatory "hot" tube is disposed member into a pulsating flow which flows through an injector substantially in the line of continuation of the gas injector and 30 tube 4 discharging at its end 5 into a chamber 6 facing inlet has at its end opposite from the inlet aperture an ad- aperture 8 of a receiving tube 7 terminating in an adjustable vantageously adjustable obturating or at least constricting diaphragm 9. One or more removal conduits are connected end; the "cold" by-pass comprises a chamber enclosing the to the chamber 6. The relatively long receiving tube 7 is sub-break in continuity and the adjacent end portions of the injec- stantially coaxial, at least at its inlet end, with the injector tor and the or each "hot" tube. 35 tube, and the diameter of the receiving tube 7 is greater than In one embodiment of the present invention, two receiving that of the injector tube 4, so that the pulsating flux leaving the tubes forming a fork extend from a chamber to which the in- latter and passing across the break in continuity 5-8 is coljector delivers a jet which is deflected alternately to the arms lected with the minimum loss.

of the fork by an aerodynamic fluid bistable, thus producing The wave nature of the successive surges of pulsating gas incompressive wave phenomena in the tubes. The expanded and 40 jected into the receiving tube 7, each surge acting like a fluid cooled gas is taken from the chamber. piston thrown into the tube, its shock being absorbed as it It has been found that gas cooling can be substantially im- moves along the tube, produces heating, with a corresponding proved by substituting for the two forked tubes a plurality of rise in temperature, so that the tube 7 can be called "hot." receiving tubes which are disposed side-by-side, preferably in Vice versa, the by-pass from the break in continuity 5-8 the shape of a fan, and whose inlet apertures are separated by 45 formed by the chamber 6 and the removal conduit is the sharp edges, the jet being oscillated at a predetermined place where gas is expanded, with a corresponding drop in frequency so that it sweeps the inlet apertures. temperature, so that the by-pass can be called "cold." Clearly, Advantageously the injector comprises a nozzle in the form the words "hot" and "cold" are purely relative and are used in of a slot or rectangle extending perpendicularly to the sweep- relation to the gas injected at the place 4. ing plane of the jet; the receiving tubes comprise over a cer- 50 At the limit, when the diaphragm 9 is in the completely obtain length of their inlets portions of straight section also in the turated position, the receiving tube 7 has no flow and behaves form of a rectangle extending perpendicularly to the sweeping merely like a heat generator, the whole flow passing through plane of the jet. the by-pass 6-10 with a marked drop in temperature in corn-In one embodiment of the present invention, the oscillatory parison with the flow injected at 4. Experience shows that the deflection of the jet is produced by an aerodynamic bistable 55 opening of the diaphragm 9 produces an intensified degree of comprising piloting circuits which determine the frequency of cooling in the chamber 6, this being of course at the expense the oscillations. of the "cold" flow, which is reduced in relation to the initial The present invention also covers cold-producing uses of a flow by the "hot" fraction delivered by the diaphragm 9. Ad-system according to the invention, inter alia for the air condi- justment of the diaphragm 9 therefore enables the reduction tioning of vehicles and the liquefaction of gases. However, the 60 in temperature and the "cold" flow to be metered in the op-most advantageous use seems to be for the removal of gasoline posite direction. Of course, when fully open, the diaphragm 9 or the separation of the condensable products from natural still has a substantially smaller flow section than the straight gas, since a substantial proportion of such products is simply section of the receiving tube 7.

wasted at the excess gas burners, for want of an economical In the variant shown in FIG. 2, the receiving tube 7 has a recovery means. The present invention provides a recovery 65 widened enclosure or chamber 11 which increases the yield of means which has the further advantages of being simply and the system, as experience has shown.

robustly constructed, requiring substantially no maintenance, The overall length of the system can be reduced by conand using for its operation no other energy than the internal structing at least a portion of the receiving tube 7 in the form energy of the natural gas. of a coil, as shown at 12 in FIG. 3.

According to the invention the natural gas when first In the variant illustrated in FIG. 4, the tube 7 has over a sec-emitted is delivered to the cooling system or more precisely its tion 13 thereof a section which first increases, then decreases, injector, the continuous pressurized gas flow being converted In the embodiments disclosed hereinbefore, the hottest porinto a pulsating flow, gas being expanded and cooled in the "- tions of the receiving tube 7 can be formed with fins (not cold" by-pass chamber to produce appreciable condensation shown), to encourage heat exchanges with the surrounding and gasoline recovery. 75 medium.

Unlike the preceding embodiments, the embodiment illus- The pressurised gas passing through the nozzle forms a sonic trated in FIG. S has a forked double injector tube having arms jet in a chamber 34 bounded, facing the nozzle 33, by the inlet 4a, 4fc, a fluid bistable of a known type, as disclosed in the apertures of a bunch of receiving tubes 36. The apertures afore-mentioned French Pat. No. 1,55,617, being substituted are also rectangular, of height h and width e; they are for the rotary needle valve. As a brief reminder, a bistable of 5 disposed side-by-side, forming an arc centred on the axis XX

the kind specified mainly comprises a rectangular pipe 14 for of the injector 1 and separated by sharp edges 37. The tubes accelerating the pressurized gas, the outlet of the pipe 14 hav- 33 forming the bunch 36 extend in the shape of a fan and each ing two opposite apertures interconnected by a loop 15. comprise a portion 38a of the same rectangular shape as its The operation of a bistable of the kind specified is known. aperture 35, the portion 38a being connected to a portion 3Sb When the compressed gas first arrives in the pipe 14, the flat- 10 of circular section obturated at 38c.

tened rectangular jet escaping therefrom plays at random on Two piloting circuits 39, disposed on either side of the one or the other of inclined walls 16a, 16fe which continue the injector 31 each discharge into the chamber 34 via an aperpipe 14 and bound the outside of the injector arms 4a, 4ft. As- ture 41 separated from the nozzle 33 by a common wall 33a suming, for instance, that the jet plays on the wall 16a, the jet and separated from an outlet aperture 42 of the chamber by a acquires overspeed thereon and causes at that place a negative l:> waij 43 having a sharp edge 44. Each of the piloting circuits pressure which balances the centrifugal force due to the comprises a tube connected on the one hand to the aperdeflection. Since the negative pressure is transmitted via an ture 41 j on the other to a chamber 46 and comprising a orifice in the wall 16a and the loop to the opposite orifice constriction 47. Extending from each of the outlet apertures in the wall 16ft, the equilibrium is broken and the jet plays 42 is a tube 48 which enables the expanded and cooled gas to against the wall I6b, and so on, the jet oscillating between "" be removed from the chamber 34.

these two positions with a frequency which is a function of the when the pipe 32 js supplied with a pressurized gas, the jet length of the loop and its response time. Two pulsating delivered by the nozzle 33 to the chamber 34 oscillates, a flows of identical frequency, but out-of-phase, are therefore frequency determined by the piloting circuits 39,40, between finally collected in the injector arms 4a, 4ft 1 which terminate two ,imit positions shown diagrammatically at 49 and 50. Durin a circular section and follow the inclined walls I6a, 16ft. ing oscillatory movement, the jet sweeps the inlet aper-

The injector tube arms 4a, 4ft are continued, with gaps 19a, tufes 35 produces in the tubes 38 surges which compress 19ft, by receiving tubes , 7ft terminating in adjustable and heat the initiall >t fest in the tubes 3g At ,he same diaphragms 9a 9ft, fins 18, 18ft being provided at suitable [ime im Uent dr in ternperature and is then forced places. Disposed around the gaps 19a, I9ft, at whose edges 3Q backiafterpassing thejetiinto thechamber 34 and evacuated small so-called "shock plates 24 are disposed wh.ch stop or vja out,ets 42 and the mbes 48 This enab,es a con.

reKCCt, 1 WTSuPfTga T ?6 apeTUr f the siderable proportion of the flow (for instance, percent) to tubes 4a 4ft, is a smgle chamber 17 to which a conduit 21 ,s at- fae J J effectivel M the whole flow However, the tached for removing the cold flow. resu jn t erature is far ter than that which Of course, the single chamber 17 can be replaced by mde- 35 can be obtail d with e ms desc ibed hereinbefore. This pendent chambers, as 17 17ft m FIG. 6, each chamber hav- frequency of oscillaing its gas-removing conduits 21a, 21ft. .. r ...f . T, . ,. , , j , .

Alternatively, as shown in FIG. 7, the gap 19 can be placed tlon of ? Jet e ApP1"" have <wved inter aha that a upstream of the forking of the receiving tubes 7, 7ft, in system of particular configuration and dimensions has an opwhich case the injector tube is reduced to a very short section 40 tlmum P?y wh fh Produces the greatest drop in the temin the continuation of the pipe 14. 4 P6 of the Pnt gas, on cond:t,on that the frequency In this embodiment the deflection of the jet coming from ls 1.. . , the pipe 14 is not controlled by a single loop connecting the The frequency mainly depends on the conformation, aropposite apertures, as in the preceding embodiments, but by a "ngement and dimensions of the pdotrng circuits 39, 40, pilot bistable 22 having a control loop 23 and receiving via a 45 more particularly on the length of the tubes 45, the position conduit 24 a continuous flow which can come inter alia from d s"e f the constncdons 47 and the volume of the chamthe source 1 However, other parameters also affect the value of Alternatively, there need be no control apertures the frequency and more particularly its stability, inter alia the downstream of the pipe 14 and no ancillary ducting systems. len of the portions of the tubes 38 and the temperature The action of the bistable can also be based on the natural 50 of e tabes 38smce a c ns>derable rise in temperature in the properties of fluid flows which tend to stick to a convex wall tubes 38 corresponds to the strong drop in pressure and tem-

Coanda effect) and to be separated therefrom as a result of perature of the impellent gas, and the Applicants have obthe formation of boundary layers at relative excess pressure. served this drop in temperature can be increased and the FIG. 8 illustrates a variant embodiment of this kind. stability of the frequency improved by vigorously cooling the In the embodiment illustrated in FIGS. 9 and 10, a continu- 55 bunch 36 of tubes> for "stance by means of a water-circulatous flow is again converted into a pulsating flow by means of a inS apparatus shown diagrammatically at 51 with its water mechanical moving member, in this case a rotary distributor inlet and discharge pipes Sic, 51ft respectively.

receiving the continuous flow in its axis and feeding radi- ff the portions 38a of the tubes 38 are too short, the ally into a plurality of injector tubes 4 which are disposed in frequency cannot be stabilized at its optimum value, the form of a star and followed by individual receiving tubes rhe receiver capacity, which is defined by the number and <