FR2723768A1 - Pneumatic pump for solids in suspension - Google Patents

Abstract

The pneumatic pump consists of a pumping chamber (4) with an entry valve (13) connected to this chamber to allow the feed or cutting off of the feed products, a pressurisation tube (8) feeds into the chamber and is connected to a gas pressure source (20). A discharge valve (27) connects to this chamber (4) via a discharge tube (22) for the evacuation of the products. The suction of the products by the pump is obtained by the creation of a vacuum by the intermediary of a vacuum producing machine (46) joined to the upper part of the chamber by a pipe (38).

Description

 The present invention relates to a pneumatic pumping device for pumping by suction and then discharging dense products.

 The operation of this device can be continuous or discontinuous. Dense products may or may not contain a liquid.

 I1 may, for example, be sludge such as is encountered in many industrial installations, as well as in many local authority installations, in particular for the treatment of waste water.

 The pumping device can be intended to be placed on the site of pumping, that is to say in a dry dock of a ship, in sewers or industrial containers.

 It can also be intended for pumping various products contained in water such as, for example, fish in fish farms, algae, plastics, sands, pebbles, heavy fuel oil, petroleum, dust and other waste.

 A device of this type is described in French patent applications N 84.07.927 and 88.07.728 filed by the applicant.

This device includes:
- a pumping chamber,
an inlet valve in communication with said chamber in order to supply it or cut off its supply of products,
- a pressurization tube opening into said chamber and connected to a source of compressed gas,
- An outlet valve in communication with the chamber via a drain tube opening into said chamber for the evacuation of products.

 According to the invention the suction of the products by the pump is obtained by the creation of an air vacuum produced by means of a pressure-reducing device.

 The present invention also relates to the characteristics below, considered in isolation or in all their technically possible combinations.

- The pressure-reducing device is in communication with the
pumping chamber via tubing
leading to its upper part.

- On this tubing is placed a pneumatic valve
interposed between the chamber and said pressure-reducing device.

- A non-return valve is interposed between the valve
pneumatic and the pressure reducing device so that
allow the isolation of the vacuum created between the
pumping and the pressure-reducing device arranged downstream of said
valve. The latter detects the high level of liquid or
system sludge, i.e. the complete filling of the
pump body.

- A pipe connects the pressure-reducing device and the valve
non-return, pipe on which a
vacuum gauge.

- The inlet valve opens into the pumping chamber by
through a filling tube arranged in
a high point of said chamber in its upstream part.

 Furthermore, the inlet valve is connected at its upper part to a suction or filling pipe.

- The piping has, on the upper generator of its
upper part, of a pneumatic valve in connection with a
water tank suitable for automatically enabling
humidification of aspirated products when they are
dry.

- The pumping chamber has a bottom, near the
upper part, from which opens a tube
compressed air injection, from a
inlet solenoid valve.

- The pumping chamber extends towards the outlet valve
by a substantially frustoconical convergent
offset downward, in the extension of the
lower generator of the chamber and according to a
gradient such as the lowest point level, in
the upstream end of said chamber, is higher than
the level of the highest point of the downstream end of the
converge.

- The pumping chamber extends towards the outlet valve
by an elbow of diameter equal to that of said chamber and
on which a converging frustoconical shape is reported
interposed between the elbow and the valve. Such a set
being arranged to respect the same gradient cited
previously.

- The device according to the invention is paired with a second
identical device by means of
synchronization of the different suction phases by the
vacuum and discharge by compressed air, so as to obtain
continuous operation of the pump 4.

 It should be noted that the supply piping is partly rigid and partly flexible, so as to make the latter mobile in order to be moved manually or automatically in the places where sludge or solid materials are to be extracted, this is that is to say in the low point of a cleaning pit, a sewer, in a fish breeding tank in fish farming, or any other soiled place or solid matter to be pumped.

 The suction and pumping device according to the invention is of a very simple structure, since it comprises only very few mobile elements.

 The synchronization of operation of the various pneumatic elements of this pump associated with the vacuum, makes it possible to make this pump suction and discharge by using a limited number of moving mechanical parts.

 Thus, this new device intended to draw solid, liquid, charged or viscous materials into the pump body, then to discharge these charged products, makes it possible to overcome the drawbacks of "slurry pumps" according to the state of the art, by simplifying the structure and limiting as far as possible the number of moving parts, in order to overcome the problems of friction, heating, lubrication and wear associated, as well as problems related to the drive members moving parts.

 In particular, another object of the invention is to provide a device for pumping liquids loaded with solid and powdery materials, which is by explosion-proof design (without motor or electrical connection), perfectly sealed (without cable gland, nor seal) therefore anti-pollutant, with constant performance and low energy consumption.

 Another object of the invention is to provide a suction and pumping device for loaded liquids, solid or powdery materials that are easy to transport and install, at a very economical purchase and maintenance cost.

 Another object of the invention is to provide an abrasion-resistant suction and pumping device capable of conveying heterogeneous sludge or solid or pulverulent materials containing solids whose size can be relatively large and which are immersible. .

 The device according to the invention makes it possible to completely evacuate the volume of solids or charged liquids contained in the pumping chamber through a discharge pipe which is connected to the pump body at the level of the orifice. output of this pump.

 In addition, the device according to the invention is of a structure such that after a stop, it can be put back into operation without fear of clogging of the tubular body and of the discharge pipe. Indeed, a vacuum operation of the system according to the invention does not cause any harm to the pumping apparatus. It is even advisable at the end of use of the device to send the pressurized gas alone, in order to completely drain the discharge product from the pump.

 In general, the device according to the invention allows the suction of dense products contained in water or any other liquid to a depth greater than 10.33 m, maximum suction height for any vacuum device, and also the possibility of cleaning any surface covered with solids, dust, rubble, sand or waste in the dry state or contained in a liquid. These products can be lifted up to a height of 60 m.

 Such a pump is also suitable for operating submerged, at sea, river, canals or in any tank or container. The proposed system is by explosion-proof design (without electric motor), perfectly waterproof, with constant performance for well defined delivery conditions and low energy consumption.

 It is also resistant to abrasion, capable of transporting heterogeneous sludges containing solids, the size of which can be relatively large depending on the diameter of the suction pipe used.

The invention will be further illustrated, without being in any way limited, by the following description, given with reference to the appended drawings, in which:
Figure 1 is an overview of a pneumatic pumping device according to the invention in a first embodiment.

 Figures 2 and 3 are respectively front and top views partially showing a second embodiment of the invention.

 Figure 4 is an overview of a pneumatic pumping device according to the invention in a third embodiment.

 The device shown in Figure 1 comprises a tubular body consisting of a cylindrical shell 1 whose downstream end la is welded to the upstream end 2a, having the largest cross section, of a convergent 2, extending downstream the ferrule 1. The convergent 2 has substantially the shape of a truncated cone offset downwards, so that its lower generatrix is an extension of the lower generatrix of the ferrule 1.

The welded assembly 1 and 2 slopes downstream from upstream to downstream, so that the level A of the lowest point in the upstream end lb of the shell 1 is higher than the level B of the point the above the downstream end 2b of the convergent 2. These conditions are fulfilled when the lower generatrix of the body 1 and 2 is inclined at an angle a of the order of 15 relative to the horizontal.

 The upstream end 1b of the ferrule 1 has an angular flange 3 projecting towards the outside of the ferrule 1. This flange 3 is attached by welding to the ferrule 1, which is itself fixed by bolts through the holes 5 drilled on this flange 3 to another flange 6, itself pierced with holes 5 'and added by welding to a convex bottom 7.

 The particular shape thus defined of the tubular body constitutes a pumping chamber or pump body 4, made of ordinary steel, stainless steel or steel coated internally, or also of plastic material making it possible to limit the consumption of compressed gas during the emptying of the pumping chamber 4 and guarantee its perfect emptying.

 The compressed gas admitted into this pumping body or pumping chamber 4 takes place in the convex bottom 7 through the pressurization orifice 9a, this pressurization orifice 9a is obtained by welding an injection pipe 8 which opens out in the convex bottom 7. This injection pipe 8 is tangentially connected to the convex bottom 7 and on its central part.

 This tubing 8 is extended upstream by a flexible or rigid pipe 8a, the connection between the pipes 8 and 8a being by union-union 9 or bolted flange. These pipes 8 and 8a are connected upstream to a channel of an inlet solenoid valve 20, in connection with a source of compressed gas via a second channel 20a and the third channel 20b of which is intended to be put in the open air, that is to say in connection with the system's decompression circuit. The valve 20 is controlled by a control box 20c comprising in particular electric, electronic or even pneumatic timers.

 Between the three-way solenoid valve 20 and the pressurized air supply pipe 8a, a pneumatic ball or sleeve valve 10 is installed, a valve which isolates the pump body from the open air, when performing vacuum in the system.

 On the cylindrical shell 1 of the pump body 4 opens at its high point and in its upstream part the orifice of the filling tube 11 of said pump. This tubing 11 is attached by welding to the ferrule 1.

 This tubing 11 has a flange 12 which is itself attached to the tubing 11 by welding.

 Upstream of the flange 12 of the filling pipe 11 is fixed on this same flange 12 a pneumatic inlet valve 13 with deformable or pneumatic sleeve, with ball, or with drawer. The fixing is carried out by bolts on the flange 12, thanks to the hole 14 provided for this purpose on the flange 12 and the holes 15 of the pneumatic valve 13.

 On the upper part of this valve 13 is fixed a suction or filling pipe 16, thanks to the holes 18 of a flange 17 of the pneumatic valve 13 and to the holes 18 'of the flange 19 added by welding to the pipe 16 , this assembly being carried out by bolts.

 At the pump outlet 4, that is to say at the downstream part of the convergent 2, a flange 21 is attached by welding. On this flange, an elbow 22 is fixed, each end of which has a flange added by welding.

 The flange 23 of the elbow 22 is fixed through the holes 24 and 24a by bolts on the flange 21 of the pump outlet.

In the upper part of this elbow 22, the flange 25 makes it possible to fix, thanks to the holes 26, also by bolts, a pneumatic, ball, slide, or diaphragm outlet valve 27, thanks to the holes 26a of the flange 28 of this valve 27.

 On the upper flange 29 of the pneumatic valve 27, a non-return valve 30 with a ball, or with a flap valve, is fixed by a bolted assembly of the flange 31 of the non-return valve and the downstream flange 29 of the valve tire 27, thanks to the holes 32 and 32a provided for this purpose.

 On the upstream flange 33 of this non-return valve 30, the delivery pipe 34 is fixed, which has at its upstream end an annular flange 35 attached by welding to the tube 34 and which is fixed by bolts to the downstream flange 31 of the non-return valve 30, thanks to the holes 36 of the flange 31 and to the holes 36a of the flange 35 welded to the delivery tube 34.

 The downstream end of the discharge pipe 34 opens directly into the open air or into a tank having a vent, or into a pressure line and / or into a pot for receiving the sludge or charged liquids , or pulverulent and expansion of the compressed gas. This tranquilizer pot 37, called a double-walled expansion pot, prevents projections of sludge or liquids loaded at the downstream end of the delivery tube 34.

 On the upper part of the cylindrical shell 1 of the pump body 4, is welded in its downstream part, a tube 38 on which is welded a flange 39. This flange 39 is fixed by bolts through the holes 40 of the flange 39 to a pneumatic ball valve or pneumatic slide valve 41, thanks to the downstream flange 42 of this valve pierced with holes 40a.

 On the downstream flange 42a of this pneumatic valve 41, a non-return valve 43 with a ball or a valve 43 is fixed by bolts thanks to the ball 44 upstream of this valve and to the holes 45 and 45a drilled respectively on the flanges 42a and 44 .

 The non-return valve 43 makes it possible to isolate the pump body 4 and a pressure-reducing device 46, which lowers the pressure, located downstream of this valve when the pump body is filled with sludge, and to maintain a pressure difference .

 On the downstream flange 47 of this non-return valve, is fixed by bolts a flange 48, itself welded on the upstream part of the piping 50. This flange 48 of the piping 50 is fixed by bolts on the flange 47 of the valve non-return, thanks to the holes 49 of the flange 47 and to the holes 49a of the flange 48 provided for this purpose.

 This pipe 50 is connected to the pressure-reducing device 46. On this pipe 50 in vacuum, an electric contact vacuum pressure gauge 51 detects an increase in the vacuum in the pipe 50 when the pump body is filled. This pressure gauge 51 is installed on a threaded end piece 52, itself attached by welding to the pipe 50.

 The vacuum or vacuum device has the following operation. When the ball of the non-return valve 43 isolates the pump body from the vacuum and the pressure switch 51 cuts off the production of vacuum, a pneumatic ball valve 53 screwed onto a sleeve 54, itself added by welding to the piping 50 allows to raise the pressure in this piping. This valve 53 operates at the opening and closing of the pneumatic valve 27 located at the delivery of the pump body.

 The valve 53 establishes the connection with the open air when the valve 27 opens (system emptying phase) and closes at the same time as the valve 27 (system filling phase).

 In fact, when the filling of the pump body 4 is detected by the operation of the non-return valve 43, the vacuum rate increases in the piping 50 located between the non-return valve 43 and the pressure-reducing device 46; the pressure gauge 51 detects the decrease in pressure and establishes an electrical signal which actuates the closing of the pneumatic valves on the circuit producing the vacuum on the suction or filling piping 16 of the pump body 4 and also causes a venting free of piping 50 via pneumatic valve 53.

 The electrical signal also feeds the coil of the three-way solenoid valve 20 for the supply of pressurized air into the pump body 4 via the tube 8a, 8 fixed tangentially to the convex bottom 7. This air drains the pump body through delivery piping, the pneumatic valve 27 with sleeve, ball, or slide valve was also controlled in the open position by the signal established by the vacuum pressure gauge.

 At the end of emptying, the compressed air inlet solenoid valve is closed and establishes communication with the outside, so as to decompress the pump body 4 for a given time. A timer then controls the closing of the pneumatic ball or diaphragm valve 10 located on the compressed air circuit between the three-way valve 20 and the tubing 8 in communication with the bottom 7 of the pump 4. At this time, also closes the pneumatic ball valve 27 or slide or membrane located at the pump outlet.

 Conversely, this timer controls the opening of the valve 13 located on the sludge suction pipe, as well as the opening of the valve 41 of the vacuum circuit which again creates the vacuum in the pump body. Automatic and autonomous operation of the device is possible thanks to an electronic control unit in which relays and timers act on the control members of the various pneumatic valves, namely valve 41 located on the vacuum circuit, valve 13 located on the suction circuit, the valve 10 located on the pressurization circuit and the isolation valve 27 located on the discharge pipe at the pump outlet.

 According to an improvement of the invention, the fixed suction pipe 16 is extended by assembly by flange or quick connector of the firefighter type by a flexible or articulated pipe 26 resistant to vacuum. This flexible tubing is for example manually manipulated by an operator using a handle 57 and another handle 58. The operator has the possibility of manually or automatically actuating a manual valve or pneumatic valve 59 fixed by flange or crimped end piece on the piping articulated 56. This valve 59 will be extended by a pipe 60 fixed to the valve 59 by flange or crimped end. In the case of automatic operation of the valve 59, this valve will be installed upstream at the end of the pipe 16, the operator being able to remotely control the opening or closing of the valve. The nozzle 60 will be equipped at its downstream end with a suction nozzle 61, of the vacuum cleaner type, nozzle easily removable by fireman connection or other attachment system. This nozzle is modular according to the needs of the user. This assembly allows the operator to draw in solid or liquid waste thanks to the vacuum created in the pump body and thus to fill the pump body 4.

 On the pipe 16 is disposed on its upper part and on its upper generator a tube 62 attached by welding to the pipe 16. On this tube 62 is attached on its downstream part a flange or union-fitting 62 itself connected to a pipe rigid or flexible 64.

This piping 64 is connected at its downstream part by flange or union connection 65 to a pneumatic ball valve or pneumatic valve with deformable sleeve 66 fixed by thread or by flange on an end piece attached by welding 67 at the base of a reservoir 68 automatically filling with water or any other fluid when the suction and discharge pump pumps dry products and waste. By adjusting the water flow rate at the inlet of the reservoir, water is thus injected via the tube 16, into the pump body, so as to obtain a solid mixture plus water which can be easily pumped according to the principle of emptying the pump.

 This dilution system in water or any other liquid fluid is used when the products sucked in at the nozzle 61 are dry or insufficiently humidified.

 The assembly of this suction and discharge pump is fixed on a base 69 attached to the elements 1 and 2 of the pump body 4 by welding point. This base 69 can be fixed on a mobile cart or placed on the floor.

 A lifting ring 70 is welded to the body 1 of the pump 4, which allows the lifting of the system or its immersion.

 This type of suction and pressure pump can be submerged, for certain depths ballasting is necessary and fixed on the base 69. This pump is suitable for taking samples from the bottom of a body of water, a canal, a river or at sea. For certain types of pumping of dense, viscous products, two nozzles 70 and 70a are added to the lower generator of the cylindrical element 1 of the pump body 4 after drilling of the body 4 by welding on the element 1 and element 2. These tappings are made and positioned so that the downstream orifice, that is to say inside the body 2 of the pump 4, are "covered" or protected against possible blockages. Protections of the perforated capsule type 71 and 71a are added by welding to the downstream end of the end pieces 70 and 70a.

 Downstream of these two tappings 70 and 70a, is attached by welding, a flange or union fitting 72 or 72a making it possible to adapt a non-return valve or pneumatic valve with deformable sleeve 73 and 73a. These pneumatic valves 73 and 73a being connected by union or by flange on an air inlet pipe 74, itself connected in this position on the pipe 8a for injecting air into the pump body 4. This sending of compressed gas in this piping 74 makes it possible to effect efficient mixing between the fluid coming from the liquid fluid reservoir 68 and the solids sucked through the piping 16, 56 and 60.

 According to a variant known as the second embodiment shown in FIGS. 2 and 3, when the products to be extracted are mainly solids, pebbles, gravel, and any other solid, the pump body 4 is given a different shape, in that sense that the convergent 2A, that is to say the offset frusto-conical part is replaced by an elbow 75 of diameter equal to the diameter of the ferrule 1. This elbow 75 varies from 60 to 90 depending on the type and size of the solid materials to convey.

 This elbow 75 is attached by welding at its upstream end to the downstream end of the cylindrical part 1. The part 2A, that is to say the convergent, is attached by welding from its upstream part to the downstream part of the elbow 75. The flange 21 welded to the downstream part of the convergent 2 is as previously connected by bolts to the elbow 22 and the mounting of the discharge pipe is the same as that described above. The purpose of elbow 75 is to avoid, during filling, an accumulation of solid towards the outlet of the pump. An accumulation at the outlet could be the cause of blockage. The outlet of the pump ending in the flange 21 is located at level B ', so that the level A at the lowest point of the upstream end of the shell 1 is higher than the level B 'from the highest point of the downstream end of the converging 2.

 In a third embodiment of the invention shown in Figure 4, for facilities in the production of boilermaking and to obtain a minimum space requirement of the system, the pipes 11 for filling with products and the vacuum pipe 38 can be differently attached to the pump body while retaining the same functions.

 In this Figure 4 elements similar to those of the first embodiment as shown in Figure 1 have the same references.

 On the cylindrical shell of the pump body 1 and at its top point of its upstream part, a ferrule 120 is reported, the lower part of which is attached by welding to the pump body 1. On its upper part, a metal ring 121 is attached by welding on the upper end of this ferrule 120. In the center of this ring, it will also be reported by welding the filling pipe 11 of the pump. The downstream part of this tubing 11 is terminated by a flange 12 itself added by welding to the downstream end of the tubing 11.

 On the vertical part of the ferrule 120, the tube 38 for the arrival of the vacuum is connected by welding perpendicular to the ferrule 120, a flange 39 is connected by welding in its downstream part.

 Finally, it should be noted that for delivery heights greater than 40 m, it is possible on certain installations to install non-return valves between flanges on the delivery piping at regular intervals, for example every 35 m. These non-return type ball or flapper or deformable sleeve valves are installed between the flanges on the discharge pipe. Downstream of each non-return valve, a compressed gas injection pipe opens into the sludge discharge pipe. When the non-return valve is closed, compressed air is injected through this injection orifice, which makes it possible to evacuate the liquids charged by a discharge column subdivided into consecutive segments, delimited between two successive non-return valves and by achieving significant savings in compressed gas injected into the entire device to ensure pumping over a very long distance, possibly to a sludge receiving tank and compressed gas expansion which can be several kilometers and depending a delivery height greater than 35 m.

 The reference signs inserted after the technical characteristics mentioned in the claims, have the sole purpose of facilitating the understanding of the latter, and in no way limit their scope.

Claims (12)

 1. Pneumatic pumping device for pumping by suction, then discharging dense products and comprising in particular:  - a pumping chamber (4),  an inlet valve (13) in communication with said chamber (4) to supply it or cut off its supply of products,  - a pressurization tube (8) opening into said chamber (4) and connected to a source of compressed gas (20),  - an outlet valve (27) in communication with the chamber (4) via a drain tube opening into said chamber for the evacuation of the products, characterized in that the aspiration of the products by the pump ( 4) is obtained by creating an air vacuum produced by means of a pressure-reducing device (46).  2. A pneumatic device according to claim 1, characterized in that the device (46) is in communication with the pumping chamber (4) by means of a tube (38) opening on its upper part.  3. Pneumatic device according to claim 2, characterized in that a pneumatic valve (41) is interposed between the chamber (4) and said pressure-reducing device (46).  4. Pneumatic device according to claims 2 and 3, characterized in that a non-return valve (43) is interposed between the pneumatic valve (41) and the pressure-reducing device (46), so as to allow the isolation of the vacuum created between the pumping chamber (4) and the pressure-reducing device (46) arranged downstream of said valve (43).  5. A pneumatic device according to claim 4, characterized in that a line (50) connects the pressure-reducing device (46) and the non-return valve (43), line on which is placed a vacuum pressure gauge (51).  6. Pneumatic device according to one of the preceding claims, characterized in that the inlet valve (13) opens into the pumping chamber (4) by means of a filling pipe (11) arranged at a point top of said chamber (4) in its upstream part.  7. A pneumatic device according to claim 6, characterized in that the inlet valve (13) is connected at its upper part to a suction or filling pipe (16).  8. A pneumatic device according to claim 7, characterized in that the piping (16) has, on the upper generator of its upper part, a pneumatic valve (66) in connection with a water tank (68) capable of automatically allow the humidification of aspirated products when they are dry.  9. Pneumatic device according to one of the preceding claims, characterized in that the pumping chamber (4) has a bottom (7), near the upper part of which opens a tube (8) for injecting compressed air. , from an intake solenoid valve (20).  10. Pneumatic device according to one of the preceding claims, characterized in that the pumping chamber (4) extends towards the outlet valve (27) by a convergent substantially frustoconical shape offset downward, in the extension of the lower generatrix of the chamber (4) and according to a slope such that the level A of the lowest point, in the upstream end of said chamber, is higher than the level B of the highest point of the downstream end of the converge 2.  11. A pneumatic device according to one of claims 1 to 9, characterized in that the pumping chamber (4) extends towards the outlet valve (27) by an elbow (75) of diameter equal to that of said chamber and on which is attached a convergent (2) frustoconical shape, interposed between the elbow (75) and the valve (27), such an assembly being arranged to respect a slope such that the level A of the lowest point of the end upstream of the chamber (2) is higher than the level B 'of the highest point of the downstream end of the converging 2A.  12. A pneumatic device according to any one of the preceding claims, characterized in that it is paired with a second identical device by means of synchronization means of the various phases of suction by vacuum and discharge by compressed air, so as to obtain continuous operation of the pump (4).