FR2711191A1 - Fluidic pump assembly. - Google Patents

Abstract

The invention relates to a pumping fluid assembly. It relates to an assembly which comprises at least one charge tank (1, 2), a first fluidic device (21, 24) placed between a liquid outlet (6) and the charge tank (1, 2), a second fluidic device (20, 23) placed between a liquid inlet (5) and the charge tank (1, 2), and an assembly (3) for pressurizing and depressurizing the charge tank (1, 2) alternately. The pressurizing and depressurizing assembly (3) comprises a chamber (7) communicating with the charge tank (1, 2), a piston (8) placed in the chamber, and a motor device (9, 10) intended to cause a reciprocating movement of the piston (8) without connection thereto. Application to the pumping of radioactive liquids.

Description

The present invention relates to pumped fluid assemblies.

  Fluidic pumping assemblies have been found to be suitable for the movement of radioactive or noxious fluids, as they do not include any moving parts that may require maintenance and could therefore pose a risk to maintenance personnel. An example of a known fluidic pumping assembly comprises a charge reservoir containing the liquid to be

  pump and connected to supply and evacuation tubes.

  by fluidic devices, for example vortex diodes. The charge tank is pressurized alternately with a motor gas and is then vented so that, when it is under pressure, the charge tank expels the liquid through the discharge tube, and when it is

  ventilated, it sucks liquid from the feed tube.

  A disadvantage of this known assembly is that the engine gas comes directly into contact with the pumped liquid. This phenomenon causes a possible contamination of the engine gas

  which, when broken down, should be treated for extrac-

  contamination before venting to the atmosphere. Since the engine gas streams may be essential quantities for a gas treatment plant, the treatment facility must be significantly larger and more expensive than it would have been.

been necessary otherwise.

  One method for solving this problem is the production of a liquid barrier between the engine gas and the radioactive liquid that is pumped. An example of this process is described in British Patent No. 2,220,709 according to which a secondary gas is trapped between the barrier liquid and the radioactive liquid. When a pressurized engine gas is applied to the barrier liquid, the entrapped secondary gas is pressurized to move the radioactive liquid from a displacement reservoir into a

  fluidic straightening device to an evaluation tube

  cuation. Thus, the engine gas does not come into contact with the

  radioactive liquid. However, the barrier liquid itself

  The same may be contaminated by diffusion or excessive displacement, and thus does not provide sufficient protection against indirect contamination that may allow the vented gas to be vented to the atmosphere without being subjected to at least one precautionary treatment. Another disadvantage of this pump assembly is that it is necessary to use a relatively complicated priming operation. The object of the invention is to provide a

  fluidic pump assembly having a preferred arrangement

  pressure and pressure reduction of the charge tank, which do not have the

aforementioned drawbacks.

  The invention thus relates to a fluidic pump assembly comprising at least one charge reservoir which contains a liquid to be pumped and which communicates with a liquid outlet and a liquid inlet, a first fluidic device placed between the liquid outlet and the reservoir. a second fluidic device placed between the liquid inlet and the charge tank, the first and second fluidic devices having a low resistance to the flow of the liquid in a first direction and a high resistance to the flow of the fluid. liquid in the other direction, and a pressurizing and depressurizing assembly for alternately pressurizing and depressurizing the charge tank so that, when the charge tank is pressurized, the liquid is discharged by the first fluidic device and the liquid outlet, and, when the pressure tank is depressurized, the liquid is sucked by the liquid inlet e and the second fluidic device, wherein the pressurizing and depressurizing assembly comprises a chamber communicating with the charge reservoir, a piston placed in the chamber, and a motor device for causing reciprocating movement of the connectionless piston. the displacement of the piston in the first direction causes the pressure reservoir to be pressurized, and the displacement of the piston in the other direction causes the pressure reservoir to be depressurized. The piston driving mechanism preferably comprises a solenoid winding and an electrical source for supplying the solenoid winding, so that when energizing the solenoid winding, the piston moves by magnetic attraction. Preferably, the driving device comprises a control device which may comprise at least one

  detector which detects the presence of the piston and which is intended to trigger the electrical excitation of the solenoid winding when detecting the presence of the piston.

  In a preferred embodiment of the invention,

  the training device comprises a first winding

  solenoid placed outside the chamber, near

  one end of it, and a second one

  solenoid located outside the chamber near its other end, the control device being adapted to alternately energize each solenoid coil in turn so that it causes a displacement.

alternate piston.

  The control device may comprise at least two detectors for detecting the presence of the piston, one of the detectors being placed towards one end of the chamber and the other towards the other end of the chamber, the arrangement being such that the detectors, when they detect the presence of the piston, trigger the supply of the solenoid winding to the end

  opposite to that to which the piston is detected.

  In a preferred embodiment of the invention, the first and second fluidic devices comprise

each a tourbillon diode.

  It is advantageous that the fluidic pump assembly comprises two load receptacles, one which communicates with a first end of the chamber and

  the other with the other end of the chamber, so that the reciprocating movement of the piston alternately causes the pressurization and depressurization of each of the charge tanks, in opposition to the phase.

  Preferably, each of the charge tanks communicates with the liquid outlet via a first diode

  vortex and communicates with the liquid inlet by a second vortex diode, the vortex diodes

  at one of the charge tanks and the vortex diodes associated with the other charge tanks

  forming a bridge fluidic rectifier.

  The chamber may be disposed vertically and may have a solenoid coil positioned outside the chamber toward its upper end, whereby the piston is lifted upon excitation of the solenoid coil and falls back under the action of the solenoid coil. from gravity to the lower end of the chamber when winding

solenoid is de-energized.

  The liquid to be pumped may contain

radioactive substances.

  Other features and advantages of the invention

  tion will emerge more clearly from the following description

  examples of embodiments, with reference to the accompanying drawings in which: Figure 1 is a schematic representation of a fluidic pump assembly in a preferred embodiment of the invention; and FIG. 2 is a schematic representation of a

  fluidic pump assembly in another embodiment of the invention.

of the invention.

  In FIG. 1, a fluidic pump assembly comprises two load tanks 1, 2, an alternating pressurizing and depressurized assembly 3, and a vortex diode bridge rectifier 4. The liquid to be pumped enters the assembly through a feed inlet tube and is discharged through an outlet tube 6. The pressurized and depressurized assembly 3 comprises a cylindrical chamber 7 placed horizontally and containing a piston 8 which contains a magnetic material which is adjusted so that it can slide easily

  in the box. An external winding 9, 10 of solenoid is placed at each end of the chamber 7. A first end of each of the windings 9, 10 is connected to a first terminal of a power supply 11 which can be a storage battery as shown .

  Other sources of electrical energy providing continuous AC power may be used where appropriate. The other end of each solenoid winding 9, 10 is connected to the contacts of a switch

  12 which is itself connected to a second terminal of the

  11. A series of detectors 13, 13a, only two of which are shown, is placed near the outer surface of the chamber 7 for detecting the position of the piston 8. Various types of detectors may be used, examples being those who put in

  acoustic, magnetic or

  tive. A possible type of detector can be operated by measuring the influence of the piston 8 on the reactance of the solenoid windings 9,10. The detectors 13, 13a are connected to a member 14 for controlling the operation of the switch 12 in such a way that the windings 9, 10 are excited alternately, so that the piston 8

  moves in translation as described below.

  The interior of room 7 communicates with

  1 through a tube 15 from the chamber to an end adjacent to the solenoid winding 9. The chamber 7 also communicates with the interior of the tank 2 charge by a tube 16 from the other end of the chamber. A liquid L, for example a radioactive hazardous liquid or of another type, forming part of the liquid to be discharged through the outlet tube 6, is contained in each of the charge tanks 1, 2. A coupling fluid F or gas is placed in the chamber 7 on each side of the piston 8, the coupling fluid also filling the tubes 15, 16 and the load tanks 1, 2 above the level of the liquid L. The coupling fluid may advantageously be kerosene when the liquid to be pumped is aqueous or, in some cases, it may include the feed liquid itself. In circumstances where compression losses may be tolerated, the coupling fluid may be air or an inert gas. When the coupling fluid is a liquid, it can be introduced into the

  tubes 15, 16 by shunt connections, not shown

  which are then closed and do not participate in

pump operation.

  At the far end of the tube 15, the charge tank 1 communicates with the rectifier 4 in diode bridge

  to a vortex tube 17. Similarly, at the end

  aunt of the tube 16, the charge tank 2 communicates with the bridge rectifier 4 by a tube 18. The tube 17 from the charge tank 1 separates to a tube 19 which interconnects the two fluidic devices 20, 21. Similarly, the tube 18 leaving the charge tank 2 separates forming a tube 22 which connects the additional fluidic device 23, 24. The fluidic devices

  , 21, 23, 24 form vortex diodes which allow

  put an easy flow of the liquid in one direction but have a high resistance to the circulation in

  the other way. Thus, the tourbillon diodes have a function

  similar to that of check valves, but differ in that they have no moving parts

  and therefore require no maintenance. This is particularly

  advantageously when the liquid L that has to be moved is radioactive and when the exposure of the personnel

maintenance must be avoided.

  The inlet tube 5 of the feed liquid separates into a tube 25 which forms a connection between the two diodes 20, 23. A tube 26 from which the outlet tube 6 forms a connection between the two diodes 21 , 24. The pump assembly operates as follows. The assembly is primed so that the liquid L to be pumped partially fills each of the charge tanks 1, 2. The coupling fluid F fills the volume

  remaining reservoirs 1, 2, tubes 15, 16 and the

  1 of the solenoid windings, for example the winding 9, is excited by transmission of electrical energy from the power supply 11 via the switch 12. magnetic material of the piston 8 is attracted by the magnetic field established by the excited winding 9, so that the piston moves towards the left end of the chamber 7 in Figure 1. With the fluid F coupling, the reservoir of charge 1 is put under pressure so that the

  Liquid L is hunted. The flushed liquid is evacuated essen-

  The diode 21 allows the passage of the liquid to the outlet tube 6, but the diode 20 is resistant to the passage of the liquid towards the outlet pipe 6, through the tube 17, the diode 21 and the tube 26. tube

input 5.

  Simultaneously, the load vessel 2 is depressurized when the piston 8 moves towards the winding 9 so that the coupling fluid F flows in the tube 16 to the chamber 7. This causes the suction of the feed liquid by the inlet tube 5 in the charge tank 2 through the tube 25, the diode 23 and the tube 18. The diode 23 allows the passage of the liquid in the charge tank 2, but the diode 24 s opposes

  passage of the liquid from the outlet tube 6.

  When the piston 8 approaches the winding 9, its position is detected in the detector 13 which emits a signal intended for the control member 14. Accordingly, this member 14 triggers the operation of the switch 12 so that the transmission of electrical energy by the power supply 11 causes the excitation of the winding 10 while the winding 9 is de-energized. This causes a reversal of the displacement of the piston 8 so that it then moves under the action of the winding 10 towards the right end of the chamber 7 as shown in FIG. 1. Thus, thanks to the coupling fluid F the charge tank 2 is then pressurized. Part of the liquid L is expelled from the tank 2 and discharged through the outlet tube 6 via the tube 18, the diode 24 and the tube 26. The diode 24 allows the circulation of the liquid 10 in this direction, but the diode 23 opposes the circulation of the

liquid to the inlet tube 5.

  At the same time, the charge tank 1 is depressurized so that supply liquid is sucked

  through the inlet tube 5 into the tank 1 through the

  of the tube 25, of the diode 20 and the tube 19 and 17. In this case, the diode 20 allows the passage of the liquid in the charge tank 1, but the diode 21 opposes the passage of the liquid from the tube of output 6. The presence of the piston 8 in the vicinity of the winding 10 of the solenoid is detected by the detector 13a which triggers the supply of the other winding 9 so that the pumping cycle is repeated. The number, the location and the connections to the control member 14 of the series of detectors 13, 13a are such that the reciprocating movement of the piston 8 is maintained. Thus, the two load tanks 1, 2 are alternately pressurized and depressurized. Thanks to the anti-phase operation, the two charge tanks, in cooperation with the rectifier 4, maintain a virtually constant flow of liquid

in the outlet tube 6.

  FIG. 2 represents another embodiment of the invention in which the references corresponding to those of FIG. 1 designate analogous parts. In this other embodiment, the chamber of the set of

  pressurized and depressurized is arranged vertically

  and has a single solenoid winding 10 placed at

  the outside of the chamber, towards its upper end.

  During operation, the winding 10 is energized by the electrical power from the power supply 11 and transmitted through the switch 12. The piston 58 is then raised towards the upper end of the

  chamber 7 by the magnetic attraction established by the winding

  10 who is excited. This causes the pressure reservoir 2 to be pressurized and the simultaneous setting

  off the pressure tank 1.

  When the piston 8 approaches the solen winding 10, its presence is detected by the detector 13a which emits a signal to the control member 14. This control member 14 triggers the operation of the switch 12 so that the winding of the solenoid is de-energized. This allows the piston 8 to fall under the action of the gravitational force towards the lower end of the chamber 7, so that the load tank 1 is pressurized and

  the load tank 2 is simultaneously switched off

  if we. When it reaches the lower end of the chamber 7, the piston is detected by the detector 13 and the aforementioned pumping cycle is repeated. Thus, as in the embodiment described with reference to FIG. 1, an alternating liquid pressure is applied to the rectifier 4 so that it creates a continuous stream of liquid in the

outlet tube 6.

  If necessary, the assembly 3 of pressurizing and depressurizing can be realized so that it controls a simpler pumping assembly ensuring intermittent evacuation of the liquid, with, during the phase without distribution of each cycle, a limited circulation in

  opposite direction depending on the functional characteristics

  vortex diodes. In such an assembly only one charge tank and a pair of complementary vortex diodes are required. For example, the charge reservoir 1 may have a pair of associated vortex diodes 20, 21, but the charge reservoir 2 and associated vortex diodes 23, 24 may be omitted. A tank connected to the tube 16 is intended to receive the coupling fluid F expelled by the piston 8 during the depressurizing stroke and to return the fluid, due to unavoidable leaks in the annular space placed between the piston 8 and the internal surface of the chamber 7. The coupling fluid F used for pressurizing and depressurizing the charge tanks is

  fully enclosed. As a result, it is not necessary

  to regularly treat the fluid in a

  active treatment, in contrast to certain prior art assemblies in which it is necessary to provide regular evacuation of air

  engine so that it undergoes such treatment.

  It is understood that the invention has been described and shown only as a preferred example and that any technical equivalence can be provided in its

  constituent elements without departing from its scope.

he

Claims (10)

  A fluidic pumping assembly, comprising at least one charge tank (1, 2) which contains a liquid (L) to be pumped and which communicates with a liquid outlet (6) and a liquid inlet (5), a first fluidic device (21, 24) placed between the liquid outlet (6) and   the charging tank (1, 2), a second fluid device   (20, 23) between the liquid inlet (5) and the   tank (1, 2), the first and the second   fluidic agent with low resistance to   liquid in one direction and a high resistance to the flow of the liquid in the other direction, and an assembly (3) for pressurizing and depressurizing the charge reservoir (1, 2) alternately pressurized and depressurized so that, upon pressurization of the charge tank, the liquid (L) is discharged by the first fluidic device (21, 24) and the liquid outlet (6), and, when depressurizing the charge tank, the liquid (L) is sucked by the liquid inlet (5) and the second fluidic device (20, 23), characterized in that the assembly (3) for placing under   pressure and pressure comprises a chamber (7)   nicking with the charge tank (1, 2), a piston (8) placed in the chamber, and a driving device (9, 10) for causing reciprocating movement of the piston (8)   without mechanical connection to it, so that   piston (8) in the first direction causes the   pressure of the charge tank (1, 2), and the displacement   piston (8) in the other direction causes the load tank pressure.   2. Fluidic pump assembly according to claim   cation 1, characterized in that the driving device   of the piston comprises a solenoid winding (9, 10)   and a power source (11) for power supply   solenoid winding, so that when energizing the winding of the solenoid, the piston   moves by magnetic attraction.   3. Fluidic pump unit according to claim 1 or 2, characterized in that the drive device comprises a control device which comprises at least one detector (13, 13a) for detecting the presence of the piston (8). and trigger the excitement   solenoid winding when detecting the presence of the piston.   4. Fluidic pump assembly according to claim   cation 3, characterized in that the driving device   The first winding (9) of the solenoid   outside the chamber (7) near a first end   mite thereof, and a second solenoid winding (10) placed outside the chamber (7) at its other end, the control device being for alternately feeding the solenoid tower windings   in turn so that they cause an alternating movement native piston (8).   5. Fluidic pump assembly according to claim   cation 4, characterized in that the control device comprises at least two detectors for detecting the presence of the piston (8), one of the detectors (13) being arranged towards a first end of the chamber (7) and   the other detector (13a) being disposed towards the other end   of the chamber (7), the pressurizing and depressurizing assembly being such that the detectors, when detecting the presence of the piston, trigger the excitation of the solenoid winding of the end of the chamber   opposite to that at which the piston is detected.   6. Fluidic pump assembly according to any one   conque of the preceding claims, characterized in that   that the first and second fluidic devices (20, 21,   23, 24) each comprise a vortex diode.   7. Fluidic pump assembly according to any one   conque of the preceding claims, characterized in that   that the assembly comprises two load tanks (1, 2), one of which communicates with a first end of the chamber and the other with the other end of the chamber, so that the reciprocating displacement of the piston causes   alternating pressurizing and depressurizing each of the charge tanks in opposite phase. 8. Fluidic pump assembly according to claim   cation 7, characterized in that each charging tank   (1, 2) communicates with the liquid outlet by a first   first vortex diode (21, 24) and communicates with the liquid inlet via a second vortex diode (20,   23), the vortex diodes associated with one of the reservoirs   charge ports and vortex diodes associated with the other charging tanks forming a rectifier fluidic (4) bridge.   9. Fluidic pump assembly according to claim   cation 2, characterized in that the chamber (7) is arranged vertically and is provided with a solenoid winding (10), placed outside the chamber towards its upper end, so that the piston (8) is raised towards the upper end of the chamber during excitation of the solenoid winding and falls under the action of gravitational forces towards the lower end of the chamber during the de-energizing of the winding of the solenoid. 10. Fluidic pump unit according to one   any of the preceding claims, characterized in that   the liquid (L) to be pumped contains radioactive substances.