EP0225416B1 - Pneumatic discontinually operating apparatus to pump charged liquids - Google Patents

Abstract

The pneumatic device for pumping a solid-carrying liquid or slurry, which operates intermittently and is continuously under load, comprises a tubular body (1) in which a flap valve (12) is mounted so that it pivots in the downstream direction on a support (8) and cooperates with a seat to close a passage port (11) at the entry of a pumping chamber (17), between the seat and the delivery port (16). A pipe (18) which allows compressed air to enter opens into the pumping chamber (17). The valve (12) is opened under the pressure of the solid-carrying liquid or slurry to be conveyed, when compressed air is not allowed to enter the chamber (17). The entry of air causes the valve (12) to close and the chamber (17) to empty. A valve (20) which is operated by a timing device (23) controls the filling and emptying sequences. The device is useful for pumping dense slurries and solid-carrying liquids.

Description

The present invention relates to a pneumatic device, operating discontinuously, for pumping charged liquids.

The invention more particularly relates to a pumping device, operating discontinuously and with compressed air, and making it possible to convey charged liquids, possibly viscous, abrasive or corrosive, such as pulp or sludge of high density having significant abrasion power.

The difficulties encountered in industry and in water treatment installations for transporting loaded liquids such as heterogeneous, abrasive or high density mud or pulps (greater than 1.6) are well known. Most of the pumps available on the market for fulfilling these functions have many disadvantages. Existing pumps, called "sludge pumps" all include at least one piston or at least one member driven in rotation by an electric motor. A lubrication installation is generally provided to reduce the friction of the mobile member (s) which generate significant overheating. In addition, the moving parts of these pumps wear out very quickly, due to abrasion phenomena.

The usual "sludge pumps" also pose sealing problems: these pumps are all fitted with packing and stuffing box which are the source of leaks and pollution, which develop over time. . Some of these pumps, in particular those which have membranes and floats, have performances which degrade over time, and, in general, the "sludge pumps" have a relatively large size, are not easy to connect to associated transport pipes and are not easily transportable. Furthermore, it is necessary during prolonged stoppages of the operation of such pumps, to carry out a cleaning of the discharge pipes, in order to avoid clogging of these pipes by the sedimentation of the transported loads. In view of the above, and since all of these known "slurry pumps" are electrically driven and driven, they are very expensive in terms of maintenance and energy consumption. Most of the existing "slurry pumps" also carry only charged liquids whose density is within a very limited density range, generally between 1 and 1.5, and, beyond a density from 1.5 to 1.6, pumping becomes difficult and the pumps that must then be used are very expensive to purchase as well as maintenance, since it is necessary to centrifuge the sludge.

Furthermore, from German patent DE-255 849, a pneumatic device for supplying bulk materials is known, comprising two identical supply containers articulated in a pendulum arrangement at the two ends of an oscillating beam, so that the containers are moved, alternately and in opposition, from a high position, in which they are filled with a material to be conveyed, to a low position, in which the load of materials is discharged from the containers. Each container comprises a tubular body inside which a filtration cartridge, retaining the dust and letting the air pass, delimits a longitudinal chamber in the upstream and downstream ends of which open respectively an inlet orifice and an outlet orifice. , which can be closed off respectively by an inlet flap valve and an outlet flap valve. In addition, two lateral pipes, one of which, upstream, is a suction pipe connected by a valve to a source of vacuum, and the other of which, downstream, is a pressurization pipe connected by another valve to a source of compressed air, open into the annular chamber delimited between the filter cartridge and the tubular body of the container.

When a container is empty and in the high position, the compressed air supply to the pressurization tubing is cut off and the outlet valve is closed. We then establish the connection of the suction pipe with the vacuum source, the inlet valve opens and the longitudinal chamber in the filter cartridge is filled, by suction, with bulk material which is brought to the inlet via a flexible pipe. During this phase, the filter cartridge isolates the suction pipe from the materials sucked into the chamber internal to the cartridge. After the suction and filling phase of the internal chamber of the filter cartridge, the corresponding container descends to the low position and the connection between the suction pipe and the vacuum source is cut. Then the connection between the pressurization tubing and the source of compressed air is established, and pressurized air is thus injected into the tubular body. The inlet valve is closed and the outlet valve is open, and the material charge contained in the chamber internal to the filter cartridge is driven out of the tubular body by the outlet orifice and discharged by a flexible pipe of evacuation.

It is clear that, because of the sequence operating cycle, like an airlock, which requires filling by suction and emptying by pressurization, this device must include two swinging valves necessary to delimit the chamber of the airlock, and the discharge pipe , downstream of the outlet valve, is never completely emptied. In addition, and above all, this device is designed to convey bulk products, but in no case loaded liquids or sludge, because it comprises an essential element for its operation, namely the filter cartridge, isolating the pipes from suction and pressurization of the materials conveyed and which would be very quickly clogged by sludge or other charges in the transported liquids, after several operating cycles.

For these reasons, a new device has been sought for pumping charged liquids and which makes it possible to overcome the drawbacks of the "slurry pumps" of the prior art and which have been presented above, by simplifying the structure and by limiting, as far as possible, the number of moving parts, in order to overcome the friction, heating, lubrication and wear problems associated therewith, as well as problems linked to the parts drive members mobile.

In particular, another object of the invention is to provide a pumping device for charged liquids which is, by design, explosion-proof (without electric motor), perfectly sealed (without cable gland or seal), constant performance (without an organ such as a membrane whose mechanical characteristics deteriorate over time), and with low energy consumption.

Yet another object of the invention is to provide a pumping device for charged liquids which is compact, easy to transport and install, and very economical to purchase and maintain.

Yet another object of the invention is to provide a pumping device resistant to abrasion, capable of conveying heterogeneous sludge containing solids whose size can be relatively large, and which is submersible.

• - un corps tubulaire délimitant une chambre interne dans les extrémités amont et aval de laquelle débouchent respectivement un orifice d'entrée et un orifice de sortie;
• - au moins une tubulure d'injection de gaz comprimés, tel que de l'air débouchant dans la chambre interne par au moins un orifice de pressurisation;
• - une vanne d'alimentation reliée à chaque tubulure d'injection et destinée à être reliée à une source de gaz comprimé pour assurer une alimentation sélective de chaque tubulure d'injection en gaz comprimé et;
• - un organe de commande de la vanne d'alimentation;

These aims have been achieved by means of a pneumatic pumping device for charged liquids, operating discontinuously, and intended to be constantly under load, either by immersion in a tank of charged liquids, or by connection to this tank by a pipe, and including:

• - A tubular body delimiting an internal chamber in the upstream and downstream ends of which respectively open an inlet orifice and an outlet orifice;
• - At least one injection pipe for compressed gases, such as air opening into the internal chamber through at least one pressurization orifice;
• a supply valve connected to each injection pipe and intended to be connected to a source of compressed gas to ensure a selective supply of each injection pipe with compressed gas and;
• - a control member of the supply valve;

and this device according to the invention is characterized in that it further comprises a single flap valve, mounted on a fixed support inside the internal chamber, between the inlet port and the pressurization orifice, and cooperating with a seat internal to the body, surrounding an orifice for the passage of the charged liquid, and delimiting, between it and the outlet orifice, a portion of the internal chamber which constitutes a pumping chamber, the pivoting flap valve of a leaves towards the outlet orifice, in the filling position of the pumping chamber, in the absence of injection of compressed gas by the pressurization orifice and under the pressure of the charged liquid tending to enter the pumping chamber by the passage orifice, and on the other hand, in the opposite direction, towards the seat against which the valve is applied in leaktight manner, in the closed position upstream and of the drained position downstream of the pumping chamber, under the effect of an injection through the pressurization orifice, compressed gas which drives the volume of charged liquid contained in the pumping chamber out of the latter through the outlet orifice, the lowest point of the pumping chamber at the seat of the flapper valve being at a level which n is not below the level of the highest point of the pumping chamber, substantially at the level of the outlet orifice.

The pumping device according to the invention is therefore of a very simple structure, since it comprises only one movable part, which is a flapper valve of an easy embodiment. In addition, it ensures total evacuation of the volume of charged liquid contained in the pumping chamber and in a discharge pipe which is connected to the body, at the outlet orifice, in order to transport any charged liquid. , dense and / or viscous, or a mud, up to the open air or in a container put in the open air. In addition, the device according to the invention is of a structure such that after an operation stop, it can be put back into operation without fear of clogging of the tubular body or of the discharge pipe.

In a particularly simple embodiment, the tubular body is constituted by the end-to-end mounting of two cylindrical ferrules (or sections of tube), assembled by the joining of two flanges of their adjacent ends, between which is held the valve support , in which the passage orifice is formed, the periphery of which, on the side of the outlet orifice, forms the seat of the valve, a single compressed gas injection pipe opening out through a single pressurization orifice in the upper part of the pumping chamber, delimited in the downstream ferrule (or section of tube). In this case, it is advantageous to additionally use ferrules (or sections of tube) which each have, at each of its two axial ends, a securing flange, the upstream flange of the upstream ferrule and the downstream flange the downstream shell being intended for example, for connection of the tubular body respectively to a supply pipe for the pumping device with charged liquids and to a delivery pipe for the charged liquid, outside the device.

However, in a preferred embodiment, which allows significant savings to be made on the volume of pressurized gas necessary to purge the pumping chamber, and at least partially, a discharge line, the pumping chamber is delimited in the tubular body consisting of an upstream part in the form of a cylindrical shell, in which a single injection pipe opens out by a single pressurization orifice, and which extends towards downstream by a convergent substantially in the form of a truncated cone offset downward.

Advantageously in this case, the upstream end of the cylindrical shell of the body has a flange for securing to a flange of the downstream end of a filling tube which opens into the cylindrical shell by delimiting the inlet opening in the body, and the flapper valve is supported by the downstream flange of the filling pipe, while the downstream end of the convergent is extended downstream by a delivery pipe having means for connection to a delivery pipe.

When the delivery line is of relatively short length, the orifice for venting the pumping chamber, necessary to facilitate filling of the latter, can be simply delimited by the downstream end of the line of repression. The compressed gas supply valve can then be a simple two-way valve. However, when the delivery line is relatively long, it is preferable for the compressed gas supply valve to be a three-way valve, one way of which allows the pumping chamber to be vented through of the injection manifold, the outlet orifice at the downstream end of the discharge line can still act as an emergency vent orifice, in the event of a valve failure.

The flapper valve can be either of a type which is pivotally mounted as a whole about a fixed axis on the support and perpendicular to the direction of flow of the liquids loaded into the tubular body, or of a type comprising a shutter mobile, intended to be applied in a sealed manner against the valve seat, a flap for fixing to the support, and a flexible part, which connects the shutter to the flap and which forms a hinge allowing the pivoting of the shutter relative to the bib.

In both cases, the flapper valve may include a rigid core, for example metallic, which is glued to or embedded in a plate of rubber material, allowing quieter operation of the device and ensuring better sealing by pressing against the seat valve.

When the device comprises flanges for fixing the constituent elements of the tubular body to each other, and / or to pipes and / or filling and / or discharge pipes, it is advantageous to allow rapid assembly and disassembly of the device, in particular for replacing the flap valve which constitutes the only consumable part of the device, that the flanges have several recesses opening in their periphery and intended to be arranged opposite one another on two adjacent flanges to be joined in order to receive, by pivoting, the threaded rods, on which are screwed nuts, of eye bolts mounted each pivoting by its eye around an axis carried by a yoke projecting outwards on the constituent element of the body, the tubing or pipe which has one of the two adjacent flanges to be secured, and so that the corresponding nut can be tightened against the other flange adjacent to s join together.

In order to allow automatic and autonomous operation of the device, the control member of the compressed gas supply valve advantageously comprises a timer triggering the filling and emptying cycles of the pumping chamber.

Finally, when the tubular body is connected downstream to a very long discharge pipe, it is advantageous to mount on the latter, at substantially regular intervals, non-return valves, each of which is preferably of the type swing valve with or without compressed gas injection pipe opening through a pressurization orifice just downstream of each swing valve, which makes it possible to evacuate the liquids charged by a discharge column subdivided into consecutive segments, delimited between two check valves - successive returns, and by achieving significant savings in compressed gas injected into the entire device to ensure pumping over a large distance, possibly up to a reception point for charged liquids and expansion of the compressed gas, and which is realized as a cyclone of relaxation.

• - la Fig. 1 est une vue schématique, en coupe verticale et axiale, d'un premier exemple de réalisation du dispositif de pompage;
• - la Fig. 2 est une vue analogue d'un second exemple de réalisation;
• - la Fig. 3 est une vue partielle et en coupe axiale d'une variante du dispositif selon la Fig. 2; et
• - la Fig. 4 est une vue partielle et schématique en coupe transversale de la variante de la Fig. 3.

Other advantages and characteristics of the invention will emerge from the description given below, without implied limitation, of two exemplary embodiments, presented with reference to the appended drawings, in which:

• - Fig. 1 is a schematic view, in vertical and axial section, of a first embodiment of the pumping device;
• - Fig. 2 is a similar view of a second embodiment;
• - Fig. 3 is a partial view in axial section of a variant of the device according to FIG. 2; and
• - Fig. 4 is a partial and schematic view in cross section of the variant of FIG. 3.

The device shown in FIG. 1 comprises a tubular body 1, constituted by the end-to-end and coaxial assembly of two cylindrical ferrules 2 and 2 ', substantially identical but arranged symmetrically with respect to the transverse connection plane. Each ferrule 2 or 2 'is in one piece, at one of its two axial ends, with an external radial peripheral flange 3, in the form of a beaten collar, while another radial and external peripheral flange 4, in annular crown shape, was added by welding on its other axial end. Due to the head-to-tail arrangement of the ferrules 2 and 2 ', the downstream flange of the upstream ferrule 2 and the upstream flange of the downstream ferrule 2' are the two flanges in beaten collars 3 arranged facing one of the other, while the upstream flange of the upstream ferrule 2 and the downstream flange of the downstream ferrule 2 'are the flanges in added crown 4. The flanges 3 and 4 are, in the usual manner, drilled in the axial direction, with holes such as 5, for the passage of bolts such as 6 on which nuts such as 7 are screwed, tightened against the flanges to ensure their attachment to each other or to other members. A support 8, in the form of a metallic annular disc, is held by pinching between the two flanges 3, tightened towards one another and against the peripheral parts of the opposite faces of the support 8, which is held in position during assembly by the passage of at least some of the bolts 6 in holes drilled in external radial lugs 9 of the support 8. The support 8, which extends transversely in the internal chamber 10, delimited in the ferrules 2 and 2 ′, also has a central and circular passage orifice 11, the passage section of which is substantially less than the internal section of the ferrules 2 and 2 '. A flapper valve 12 is pivotally mounted in one piece on the downstream face of the support 8. This valve 12 has, for example, the shape of a disc of larger diameter than the circular orifice 11, and the upper part of which is integral with a sleeve 13 by which the valve 12 is mounted journalling about a horizontal and transverse axis 14, carried by a yoke projecting from the downstream face of the support 8. The valve 12 pivots between an open position of the orifice 11 (represented in the position in broken lines in FIG. 1), and in which it is raised downstream, and a position for closing the orifice 11 (represented in solid lines in FIG. 1 ), and in which it is applied, in a sealed manner, against the seat formed on the downstream face of the support 8, on the periphery of the orifice 11. This valve 12 is metallic or preferably, with a metallic core embedded in a material rubbery (natural or synthetic rubber, silicone elastomer, etc. The upstream flanges and t downstream 5 of the body 1 respectively surround the inlet 15 and the outlet 16 of the internal chamber 10, and the valve 12 pivots in the portion of the chamber 10 which is delimited downstream, between the support 8 and the outlet orifice 16, which constitutes a pumping chamber 17. A pipe 18 for injecting compressed air opens out through a pressurization orifice 19 in the pumping chamber 17, above the level of the most bottom of this chamber 17, at the base of the valve seat, which is itself above the level of the highest point of the chamber 17, in the immediate vicinity of the outlet orifice 16, due to the inclination from top to bottom and from upstream to downstream which is given to the body 1. The tubing 18 is connected to a channel of a three-way inlet valve 20, another channel of which is connected by the tubing 21 to a source of compressed air, and the third channel of which is vented through the nozzle 22. The valve 20 is controlled by a control box nde 23, comprising in particular an electric, electronic or even pneumatic timer, and controlling the selective communication of the pipe 18, either with the pipe 21 to admit compressed air into the pumping chamber 17, or with the nozzle 22 for venting the pumping chamber 17. Through the flange 4 of its upstream end, the body 1 is connected to the downstream end of a filling pipe (not shown) connected to the lower part a tank for storing a loaded liquid or a decanter or thickener for sludge to be pumped. But it is also possible that by this upstream flange 4, the body 1 is kept immersed on the bottom of such a tank or decanter, so that the device will always be in charge. By the flange 4 of its downstream end, the body 1 is connected to the flange 25 of the upstream end of a discharge pipe 24, the downstream end of which opens directly into the open air, or into a tank at l 'free air, or in a container for receiving the sludge or charged liquids and for expanding the compressed air, of the double-walled cyclone type of expansion which prevents splashes of mud or liquid.

This device operates as follows: at the start of an operating cycle, the box 23 controls the valve 20, so that the tubing 18 and the pumping chamber 17 are brought to the open air by the nozzle 22. As the body 1 is constantly in charge, by the principle of communicating vessels, the charged liquid which enters through the inlet orifice 15 into the chamber 10, pushes the valve 12 back into the open position and fills the pumping chamber 17 , passing through the orifice 11 of the support 8. The box 23 then controls the valve 20, so that the tube 18 is placed in communication with the source of compressed air. Air under an initial pressure of about 0.6 MPa is then injected into the pumping chamber 17. Under the effect of this pneumatic pressure, the flap valve 12 is pushed against its seat on the support 8, in position closing the passage orifice 11, which isolates the pumping chamber 17 from the reservoir of sludge or charged liquid to be pumped. Simultaneously, the volume of sludge or charged liquid which is present in the pumping chamber 17 and possibly over a certain length in the discharge pipe 24, is expelled towards the outside by the discharge channel 24. If the duration of the compressed air injection is sufficient, the chamber 17 and the discharge line 24 are emptied, then the box 23 again controls the valve 21 to ensure the venting of the pumping chamber 17 and one is found at the beginning of the cycle.

Depending on the initial air pressure injected, the volume of the pumping chamber 17 and the discharge line 24, therefore its length, as well as the height of the discharge, and the charge pressure of the tubular body 1, therefore also the density of the charged liquid to transport, the setting of the timer of the control box 23 makes it possible to adjust the filling and emptying sequences of the device and their frequency.

This pumping device, the body 1 of which is made of mild steel, coated or not, of stainless steel, of sheet metal (an alloy resistant to corrosion by the liquids transported) or even of elastomer, allows pumping at low flow rate (from 1 at 10 m ³ / hour) of loaded liquid and high density mud (from 1.3 to 2.2 or even more) with delivery heights from 10 to 50 m and delivery lengths from 20 to 100 m.

The device of FIG. 2, which operates in the same manner as that described above with reference to FIG. 1, is essentially distinguished from the latter by the fact that the tubular body 31 consists, in its upstream section, of a cylindrical shell 32 whose downstream end is welded to the upstream end, having the largest cross section, of a convergent 33 constituting the downstream section of the body 31. The convergent 33 has substantially the shape of a truncated cone offset downwards, so that the wall of its lower part is substantially in the extension of the wall of the lower part of the shell 32, parallel to the inclined direction of the body 31, declining from upstream to downstream and from top to bottom, so that the level A from the lowest point in the upstream end of the ferrule 32 is higher than the level B of the highest point in the downstream end of the converging 33.

In this example, this is obtained when the lower generatrix of the body 31 is inclined by an angle a of the order of 15 ° on the horizontal. This particular shape of the body 31, made of sheet steel 4 mm thick for example, makes it possible to limit the consumption of compressed air admitted into the body 31 through the pressurization orifice 19, through which the injection tubing 18 opens into the upper part of the shell 32, this tube 18 being connected, as in the previous example, to the three-way valve 20 controlled by the timer box 23.

At its upstream end, the ferrule 32 has an annular flange 34, projecting radially outwards, attached by welding, and which is fixed by bolting, thanks to the holes 35 to a flange 38 attached by welding around a tube of filling 36, near the downstream end of the latter which opens into the upstream end of the shell 32. At its upstream end, the filling tube 36 which has substantially the same inclination as the body 31, is integral with a flange 37, substantially vertical, therefore inclined by the angle a on a transverse plane perpendicular to the axis of the tube 36. The flange 37 enables the device to be fixed by bolting directly to the outlet of a liquid storage tank responsible for transporting or keeping the device in the submerged position in this tank, or even for connecting it to a substantially horizontal loading pipe. In this example, the downstream end of the pipe 36 delimits the passage orifice 41 which can be closed by the flapper valve 42. The seat of the valve is formed by the front face of the downstream end of the pipe 36, and the valve 42 consists, on the one hand, of a rubber plate 43, fixed by bolting its upper part against a boss 39 projecting from the flange 38 towards the inside of the ferrule 32, and intended to close, sealingly, the orifice 41 and on the other hand, a metal disc 44 bonded to the downstream face of the plate 43, in order to stiffen it in the portion of the latter which forms the shutter itself, so that between the covered portion of the metal disc 44 and the portion fixed to the support 39, the rubber plate 43 has a flexible zone forming a hinge, and allowing the pivoting of the shutter part of the valve 42 between, on the one hand, the orifice 41 open position (shown in broken lines in Fig. 2), so us the thrust of the charged liquid penetrating, through the inlet orifice 45 delimited by the upstream flange 37, into the chamber 40 internal to the tube 36, and when the pumping chamber 47, which is delimited in the body 31, is vented through the tubing 18, the valve 20 and the nozzle 22, and, on the other hand, the sealed closing position of the orifice 41 (shown in solid lines in FIG. 2), under the pneumatic pressure of the compressed air which is admitted into the pumping chamber 47 by the pipe 18, the valve 20 and the pipe 21, to drain this room 47. The downstream end of the converging 33 is connected by welding (or by flange) at the upstream end of a short delivery pipe 48, the downstream end of which delimits the outlet orifice 46 of the device and is surrounded by a flange 49 added by welding. This last flange allows the connection of the device to a discharge pipe (not shown). When this discharge line is very long and in order to save on compressed air consumption, check valves can be fitted at regular intervals along the discharge line, for example every 50 m . In this way, the discharged column is subdivided into adjacent segments, which are successive and repel each other gradually during the emptying phases of the pumping chamber 47 of the device, during which the check valves are open, the segments adjacent to the pumped column being on the other hand separated by the non-return valves, when the latter are closed, during the filling phases of the pumping chamber 47 of the device.

As check valves, flapper devices such as that shown in FIG. 1, without absolutely having to give them the inclination of the device of FIG. 1. In addition, it is not necessarily necessary in this application, to use the tubing 18 for injecting compressed air from the device of FIG. 1. An injection of compressed air slightly downstream of each non-return valve is only justified if the total length of the discharge pipe and / or the system pressure losses are significant. By cons, in this case, the venting of the pumping chamber 47 of the device is imperatively ensured, for filling, by the corresponding valve 20.

In the two examples described above with reference to Figs. 1 and 2, the connections of the constituent elements of the tubular body to each other and / or to pipes or to filling or discharge pipes, are ensured by fixing flanges which are bolted in pairs using bolts passing through the opposite holes drilled in the flanges.

In order to allow faster assembly and disassembly of the device, both at the level of these connections to pipes and at the level of the support of the flapper valve, in particular to replace the latter, which constitutes the only wear and consumable part of the device, it is advantageous to use the flange fixing mechanism which is shown in the variant of FIGS. 3 and 4, at the valve flange.

In Figs 3 and 4, we find, as in the example in Fig. 2, the shell 32 of the tubular body, the tubing 18 for injecting compressed air, and an upstream flange 34 'of the ferrule 32 as well as the filling pipe 36 with its upstream flange 37 and a downstream flange 38 ', near its downstream end which opens into the shell 31 and delimits the passage orifice 41 which can be closed off by a flap valve 42'. In this variant, the valve 42 'comprises a circular rubber disc 50, of diameter slightly greater than that of the circular orifice 41, and stiffened by a metal washer 51 forming a core embedded in the disc 50, which thus forms a shutter . This disc 50 is extended, at its upper part, by a rectangular rubber flap 52, which has three holes through which it is mounted on the threaded rods of three bolts 53 with head embedded in the parallelepipedic support 39 'welded against the downstream face of the flange 38 ', and the flap 52 is clamped between the support 39' and a pressure plate 54, under the effect of the tightening of the nuts 55 on the bolts 53. The portion 56, located between the flap 52 and the disc 50, thus constitutes a flexible zone forming a hinge for pivoting the flap valve 42 '.

On their periphery, the flanges 34 'and 38', between which a seal 57 is disposed, each have six radial recesses 58, with rounded bottom, which open outwards and are regularly distributed over the periphery. A short distance downstream of each recess 58 of the flange 34 ′, a yoke 59, open towards the outside and the two branches of which are spaced apart from the width of the recess 58 and in the extension of the edges of this recess 58, is welded against the external face of the ferrule 31. A transverse axis 60 extends between the two branches of the yoke 59, and an eye bolt 61 is mounted swiveling by its eye 62 in the yoke 59, around the axis 60. An eye nut 64 is further screwed onto the end of the threaded rod 63 of the bolt 61. Consequently, after having positioned the two flanges 34 'and 38' so that their recesses 58 are grouped in pairs of facing recesses, it is possible to tilt the bolts 61 around the axes 60, so that their rods 63 are each housed in two recesses 58 opposite the two flanges 34 'and 38', and then to screw the nuts 64 onto the rods 63 for tightening the flanges 34 'and 38' towards each other. Conversely, the unscrewing of the nuts 64 makes it possible to quickly disassemble the two flanges by then rocking the bolts 61 around the axes 60, towards the outside and towards the ferrule 31. The flap valve 42 ′ is therefore thus easily accessible.

• - ils constituent des dispositifs de pompage volumétriques; à chaque cycle, l'air comprimé chasse un volume de liquide chargé ou de boue qui est égal à la somme utile de la chambre de pompage et de la canalisation de refoulement (le volume utile de cette dernière ne dépendant que de la hauteur de charge et de sa section).
• - le débit horaire est fonction du nombre de cycles par heure, commandés par la minuterie du coffret de commande 23, et ce débit est égal au nombre de cycles multiplié par le volume défini ci-dessus.
• - ces dispositifs de pompage ne comprennent qu'une seule pièce mobile, le clapet battant.
• - ces dispositifs de pompage utilisent de l'air comprimé comme fluide moteur; selon les conditions d'utilisation, la pression de l'air peut varier entre 0,6 et 0,3 MPa.
• - la commande du débit et de ses variations est très simple: la minuterie du coffret 23 commande la vanne trois voies 20, les fréquences de mise à l'atmosphère, le temps de remplissage de la chambre de pompage et la durée d'injection d'air comprimé, qui fixent le débit horaire du dispositif de pompage.
• - les causes de panne de ce dispositif de pompage sont limitées: elles peuvent être une panne de l'alimentation en air comprimé ou une baisse de pression dans le réseau d'alimentation, le blocage d'un corps entre le clapet battant et le siège, ce qui ne permet pas d'isoler la chambre de pompage du réservoir de liquide chargé à pomper, mais dans tous les cas, le démontage du dispositif en vue de sa remise en état de fonctionnement, ne demande que quelques minutes.
• - le dispositif de pompage ne comporte ni moteur, ni presse-étoupe, ni installation de graissage.
• - le dispositif de pompage est d'une étanchéité totale (aucune pollution à craindre).
• - le coût de ce dispositif de pompage est très intéressant par rapport à ceux des "pompes à boues" de l'état de la technique.
• - le dispositif de pompage permet de véhiculer des boues contenant des corps étrangers durs, abrasifs, et autres éléments divers que ne supportent pas les pompes centrifuges ou à vis.
• - ce dispositif de pompage peut véhiculer des boues épaisses de densité égale ou supérieure à 2, et contenant des billettes métalliques.
• - l'entretien d'un tel dispositif de pompage est simple et peu onéreux.
• - la consommation en air comprimé, bien que fonction des conditions d'utilisation, reste économiquement intéressante.

The devices according to the invention have the following advantages:

• - they constitute volumetric pumping devices; at each cycle, the compressed air drives out a volume of charged liquid or sludge which is equal to the useful sum of the pumping chamber and the discharge pipe (the useful volume of the latter depending only on the charge height and its section).
• - The hourly flow is a function of the number of cycles per hour, controlled by the timer of the control unit 23, and this flow is equal to the number of cycles multiplied by the volume defined above.
• - These pumping devices comprise only one moving part, the flapper valve.
• - These pumping devices use compressed air as the working fluid; depending on the conditions of use, the air pressure can vary between 0.6 and 0.3 MPa.
• the control of the flow rate and of its variations is very simple: the timer of the box 23 controls the three-way valve 20, the frequencies of venting, the filling time of the pumping chamber and the duration of injection d compressed air, which set the hourly flow rate of the pumping device.
• - the causes of failure of this pumping device are limited: they can be a failure of the compressed air supply or a drop in pressure in the supply network, the blocking of a body between the flapper valve and the seat , which does not make it possible to isolate the pumping chamber from the reservoir of liquid loaded to be pumped, but in all cases, disassembly of the device with a view to returning it to operating condition requires only a few minutes.
• - the pumping device does not include a motor, cable gland, or lubrication system.
• - the pumping device is completely sealed (no pollution to fear).
• - The cost of this pumping device is very interesting compared to those of the "slurry pumps" of the prior art.
• - The pumping device makes it possible to convey sludge containing hard, abrasive foreign bodies, and other various elements which are not supported by centrifugal or screw pumps.
• - This pumping device can convey thick sludge of density equal to or greater than 2, and containing metal billets.
• - The maintenance of such a pumping device is simple and inexpensive.
• - compressed air consumption, although a function of the conditions of use, remains economically attractive.

Claims (12)

1. Intermittently operating pneumatic pumping device for a solid-carrying liquid and intended to be under a continuous load, and comprising: a tubular body (1, 31) defining an inner chamber with an entry port (15,45) and a delivery port (16, 46) opening into the upstream and downstream ends, respectively thereof; at least one injection line for a compressed gas (18), such as air, opening into the inner chamber via at least one pressurization port (19); a supply valve (20) connected to each injection line (18) and intended to be connected to a source of compressed gas (21) to provide a selective supply of compressed gas to each injection line (18); and a means of controlling (23) the supply valve (20), and additionally comprising a single flap valve (12, 42) mounted on a support (8, 39) fixed inside the inner chamber, between the entry port and the pressurization port, and cooperating with a seat internal to the body, surrounding a passage port (11, 41) for the solid-carrying liquid, and defining, between it and the delivery port, a part of the inner chamber which constitutes a pumping chamber (17, 47), the flap valve (12, 42) pivoting, on the one hand, towards the delivery port (16, 46), in a position in which the pumping chamber is filling, in the absence of injection of compressed gas via the pressurization port (19) and under the pressure of the solid-carrying liquid which tends to enter the pumping chamber (17, 47) through the passage port (11, 41), and, on the other hand, in the opposite direction, towards the seat against which the valve (12, 42) is applied in a leakproof manner in a position in which the pumping chamber (17,47) is closed upstream and is emptied downstream under the effect of an injection, via the pressurization port, of compressed gas which expels the volume of solid-carrying liquid held in the pumping chamber, out of the latter, via the delivery port, the lowest point of the pumping chamber in the region of the flap valve seat being at a level which is at least as high as the level of the highest point of the pumping chamber in the region of the delivery port.

2. Pneumatic device according to Claim 1, characterized in that the tubular body (1) is formed by the end-to-end mounting of two cylindrical shells (2, 2'), which are assembled by joining together two flanges (3) of their adjacent ends, which hold between them the valve support (9) in which the passage port (11) is provided, the periphery of which, on the delivery port (16) side, forms the valve seat, a single compressed gas injection line (18) opening, via a single pressurization port (19), into the top part of the pumping chamber (17) defined in the downstream shell (2').

3. Pneumatic device according to Claim 1, characterized in that the pumping chamber (47) is defined in the tubular body (31) which consists of an upstream part in the shape of a cylindrical shell (32), into which a single injection line (18) opens via a single pressurization port (19), and which is extended in the downstream direction by a funnel (33), having substantially the shape of the frustum of a cone offset downwards.

4. Pneumatic device according to Claim 3, characterized in that the upstream end of the cylindrical shell (32) of the body (31) has a flange (34) for coupling to a flange (38) at the downstream end of a filling pipeline (36) which opens into the cylindrical shell (32) for defining the entry port (41) into the body (31), the flap valve (42) being supported by the downstream flange (38) of the filling pipeline (36), and the downstream end of the funnel (33) being extended in the downstream direction by a delivery pipeline (48) incorporating means for coupling (49) to a delivery line.

5. Pneumatic device according to one of Claims 1 to 4, characterized in that the compressed gas supply valve (20) is a three-way valve, one of the channels of which permits the pumping chamber (17,47) to be connected to the open air (22) by means of the injection pipeline (18).

6. Pneumatic device according to one of Claims 1 to 5, characterized in that a port for connecting the pumping chamber (17,47) to the open air is defined by the downstream end of a delivery line coupled to the outlet of the tubular body (1, 31).

7. Pneumatic device according to one of Claims 1 to 6, characterized in that the flap valve (12) is mounted so that it pivots as a whole around a shaft (14) fixed to the support (8) and perpendicular to the flow direction of the solid-carrying liquid in the tubular body (1).

8. Pneumatic device according to one of Claims 1 to 6, characterized in that the flap valve (42') comprises a movable shutter (50) intended to be applied against the valve seat in a leakproof manner, an apron (52) for fixing to the support (39'), and a flexible part (56), connecting the shutter (50) to the apron (52) and forming a hinge permitting the pivoting of the shutter relative to the apron.

9. Pneumatic device according to one of Claims 1 to 8, characterized in that the flap valve (42') comprises a rigid core (51) glued to or embedded in a plate (50) made of a rubbery material.

10. Pneumatic device according to one of Claims 1 to 9, characterized in that it comprises flanges (34', 38') for attaching the constitutent parts (31) of the tubular body to each other and/or to the filling and/or delivery pipelines (36) and/or lines, the said flanges (34', 38') having several cavities (58) opening into their periphery and intended to be arranged facing each other on two adjacent flanges (34', 38') in order to receive, by pivoting, the threaded stems (63) of the eyebolts (61) onto which the nuts (64) are screwed, and each of which pivots via its eye (62) around a shaft (60) carried by a yoke (59) projecting outwards over the part forming the body (31), the pipe (36) or the pipeline which carries one of the two adjacent flanges (34', 38') to be assembled, so that the nut (64) can be clamped against the other adjacent flange.

11. Pneumatic device according to one of Claims 1 to 10, characterized in that the means (23) for controlling the compressed gas supply valve (20) comprises a timing device which starts the filling and emptying cycles of the pumping chamber (17, 47)

12. Pneumatic device according to one of Claims 1 to 11, characterized in that the tubular body (31) is connected in the downstream direction to a delivery line, in which at least one non-return valve is mounted, and preferably a plurality, at regular intervals, if the delivery line is of great length, each of these non-return valves being, preferably, of the flap-valve type (12) with or without a compressed gas injection line (18) opening via a pressurization port (19) immediately downstream of each flap valve (12).

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