WO2008031929A1 - Reciprocating diaphragm pump for raising a non-lubricating liquid - petrol, alcohol or liquefied gas - to a very high pressure - Google Patents

Abstract

Simple reciprocating pump intended to raise a non-lubricating liquid (petrol, alcohol, liquefied gas, etc.) to a very high pressure, of up to several thousand bar. The pump is made up of a casing (1), the interior of which is separated into two independent chambers (2) and (3) by a metal diaphragm (4) which is impermeable and sufficiently flexible, of the shim kind. The lubricating liquid in the chamber (2), the cyclic pulses of which are created by the device (12), independent of the present patent, imposes its pressure and volume variations on the non-lubricating liquid of the chamber (3) without this non-lubricating liquid being subjected to mechanical friction forces. The diaphragm does not act mechanically on the two liquids that it separates. One possible use: very high-pressure injection of petrol, alcohol, liquefied gas, etc. into internal combustion engines.

Description

 Alternative pump to put at very high pressure non-lubricating liquid: gasoline, alcohol, liquefied gas, etc. The object of this patent is an alternative pump system, intended to put at a very high pressure - up to several thousand bars - a non-lubricating liquid, such as for example gasoline, or alcohol, or a liquefied gas, or an acid, etc.

This system, setting very high pressures of a non-lubricating liquid, is composed, as shown in section 1, of a closed housing (1) capable of supporting without inconvenience the high pressures required. Housing in which, cyclically, pressure variations and volume changes of a lubricating liquid are transmitted to a non-lubricating liquid without this non-lubricating liquid being subjected to mechanical friction.

A metal membrane, like foil, or any other material of the same characteristics, separates in a sealed manner and sufficiently flexible the two liquids in the housing (1).

With reference to the accompanying drawings, the interior of this housing, FIG. 1, consists of two independent chambers (2) and (3), separated in a sealed manner by a sufficiently flexible metal membrane (4) - or in any case another material compatible with liquids which pass through, each in their chamber, the housing (1). Pipes provide the communications of each chamber: the pipe (13) communicates the accessory device (12) with the chamber (2) for the lubricating liquid.

The pipe (5) and its "anti-return" (6) put in communication the chamber (3) with its supply connected to the reservoir (10) of non-lubricating liquid. The anti-return valve (6) prevents the liquid from returning from the chamber (3) to the reservoir (10). As a demonstration and not limitation, the supply may optionally be equipped with a low-pressure pump (11) which can help to fill the chamber (3) during its suction phase and thus help the membrane (4) to return to its initial position at the end of the cycle without creating cavitation (depression reaching and exceeding the vapor pressure of the liquids used)

The pipe (7), with its anti-return (8), communicates the chamber (3) with the use chamber symbolized by (9), optionally provided with an injection head symbolized by (14). L ¹ anti-return (8) prevents the non-lubricating liquid from returning from the chamber of use (9) to the chamber (3).

The lubricating liquid occupies the entire chamber (2). Its pressure and volume variations are driven by an accessory device (12), independent of this patent and whose functions, during the cycles of the pump, are detailed below.

The non-lubricating liquid occupies the entire chamber (3). II undergoes, transmitted by the membrane (4), the pressure variations and volume variations of the lubricating liquid of the chamber (2).

The membrane (4) separates, sealingly and sufficiently flexible, the two liquid chambers (2) and (3).

The lubricating liquid in the chamber (2), for example the oil given here for demonstration and non-limiting purposes (whose cyclic pulses - flow and pressure - are implemented by the accessory device (12) independent of this patent ) imposes its pressure variations and volume changes to the non-lubricating liquid of the chamber (3), without the two liquids are in direct contact, because separated in the housing by the waterproof membrane (4).

The pulsations of the lubricating liquid, in the part (2) of the housing (1), create their exact replicas of pressures and also volumes in the non-lubricating liquid in the chamber (3) of the casing (1), without this liquid non-lubricant is subjected to equipment undergoing mechanical friction.

According to the subject of this patent, the membrane waterproof (4) is very thin metal (clicking kind), or any other material of the same characteristics, that is to say: 1 - resistant to the liquids used; 2 - flexible enough to allow small but sufficient deformations during each cycle of the pump; 3 - practically without significant elasticity over its thickness, to avoid annoying disturbances of the complementary volumes of the two liquids of the chambers (2) and (3) during each cycle.

This membrane (4) which passively and sealingly separates the lubricant liquid and the non-lubricating liquid from the housing, prevents them from mixing. In the chamber (3), the non-lubricating liquid to be injected undergoes directly the volume variations and reaches the same instantaneous variations in pressure as those of the lubricating liquid of the chamber (2) transmitted by the deformation of the membrane (4).

The membrane does not intervene mechanically on the two liquids that it separates. It marries freely and passively their difference in volume by its deformations adapted to the amplitude of the variations of the volumes of the two liquids.

When the accessory device (12) - independent of this patent - sends a precise volume at a precise pressure of the lubricating liquid in the chamber (2) through the conduit (13), the volume of the lubricating liquid, already present in the chamber (2 ) increases. The membrane is deformed so that the volume of the chamber (2) corresponds to the volume of the lubricating liquid thus increased.

The volume of the chamber (3) containing the non-lubricating liquid must decrease by the same volume.

The non-lubricating liquid of the chamber (3) is then forced to escape through the conduit (7), provided with its non-return (8), to the chamber of use (9), possibly with the use of an injection system symbolized by (14). The pressure of the non-lubricating liquid escapes at the same pressure as the pressure, at this moment, of the lubricating liquid of the chamber (2).

The functions of the accessory device (12), independent of this patent, and necessary for the operation of the pump object of this patent are the following:

1 - In the first sequence of the cycle of the pump object of this patent, the accessory device (12) has the function of sending, under a determined pressure, a precise amount (and adjustable, according to the expected needs of use of the pump), lubricant liquid in the chamber (2) of the housing (1) through the conduit (13). This has the effect of pushing the membrane (4) to the chamber (3). The accessory device (12) may be provided with a pressure limiter to prevent destructive overpressures of all or part of the apparatus.

2 - In the second sequence of the pump cycle, the accessory device (12), independent of this patent, has the function of discharging from the chamber (2), by the pressure drop of the lubricating liquid, then by suction, the volume of lubricating liquid admitted during the first sequence of the cycle of the pump in the chamber (2). This has the effect of returning the membrane (4) to its initial position at the beginning of the cycle.

3 - The accessory device (12) also makes it possible, cycle after cycle, to adjust the quantity of lubricating liquid admitted into the chamber (2), according to the need for a quantity of non-lubricating liquid to be injected by the pump that is the subject of this patent and, controlled by the user and incidentally to compensate for any loss of liquid volume caused, for example, by possible leaks.

For demonstrative and non-limiting reasons:

To fulfill the functions of the accessory device (12), independent of this patent and according to its purpose: - One can create a specific equipment, integrated or not to the pump and performing the functions described above;

- An existing system can also be adapted to perform the functions described above.

By way of demonstration and not limitation, mention may be made of known systems that may be used: 1 - Piston pumps with fixed or variable stroke; 2 - The equipment, identical in principle, diesel fuel injection pumps for diesel engines but where the diesel is replaced in this new use by a lubricating liquid, for example oil, capable of withstanding the maximum pressures required; 3 - Very high pressure pumps-injectors for modern diesel engines;

4 - All vibration systems creating alternative movements where the vibration frequencies are adapted to the flow required for the pump object of this patent.

The complete cycle of the pump, object of this patent, is broken down into two successive sequences:

At the beginning of the first sequence of the cycle, the non-lubricating liquid and the lubricating liquid are previously sufficiently de-bubble by a conventional system. The membrane (4) is at its initial starting position of the cycle; the lubricating liquid occupies the entire chamber (2). It is, at the beginning of this sequence, its pressure and its minimum volume.

During this first sequence of the cycle of the pump, the lubricant liquid increases in volume and pressure in the chamber (2), by the supply of lubricant liquid from the accessory device (12), independent of this patent; the increase in the volume of the lubricating liquid in the casing (1) under a pressure determined by the accessory device (12) pushes the membrane (4) towards the chamber (3). The chamber (3) decreases and a volume corresponding exactly to the increase in the volume of the lubricant liquid introduced into the chamber (2). The non-lubricating liquid of the chamber (3) which is also carried at this time to the high pressure of the lubricating liquid of the chamber (2), is forced to escape from the chamber (3) via the conduit (7). ) and its non - return (8) to the use chamber (9), while the volume of the lubricating liquid lasts in the chamber (2).

It should be noted that the pressure of the non-lubricating liquid of the chamber (3) is, at each instant, substantially the same pressure as that of the lubricant liquid sent into the chamber (2) by the accessory device (12). The volume of the non-lubricating liquid of the chamber (3), injected into the use chamber (9) possibly by the injection head (14), is, in this phase of the pump cycle, practically the same. exact volume of liquid lubricant sent into the chamber (2) by the accessory device (12).

When, at the end of this first sequence of the pump cycle, the maximum volume of lubricating liquid introduced into the chamber (2) by the accessory device (12) is reached, the expulsion, under pressure, of the non-lubricating liquid the chamber (3), via the pipe (5) and its non-return (7) to the chamber of use (9), ceases.

The pressure and the volume of the lubricating liquid have reached the maximums determined by the accessory device (12) independent of this patent.

This is the end of the first cycle of the pump cycle.

- At the beginning of the second cycle of the pump cycle, the withdrawal of the lubricating liquid from the chamber (2), by the action of the accessory device (12), reduces the pressure of the lubricating liquid in the chamber (2) until 'to its minimum value. During the removal of liquid lubricant of the chamber (2), which can return to the reservoir (17) through the conduit (18), a depression is installed in the chamber (2). This depression recalls the membrane (4) at its initial position of beginning of the cycle. By the return of the membrane to its initial position, this depression is communicated at the same time to the non-lubricating liquid of the chamber (3) which then sucks a corresponding volume of non-lubricating liquid, from the reservoir (10), by the conduit (5) and its non-return (7). The volume sucked of non-lubricating liquid is equal to the volume of the lubricating liquid removed from the chamber (2) by the accessory device (12). The volumes of the two liquids each return to their starting volume of the cycle. And the membrane returns to its initial position at the beginning of the cycle.

This is the end of the second cycle of the pump cycle.

Unless the pump stops, a new complete cycle of the pump begins.

Possible embodiments of the subject of the present patent, variants given here for demonstrative and non-limiting purposes, are illustrated by the corresponding figures. The useful surface of the membrane can be: - Circular as shown in Figure 2, front view;

- Ovoid as Figure 3, front view;

- Square or rectangular, possibly with rounded corners, as shown in Figure 4, front view.

The housing (1), Figure 1, is adapted to the shape of the simple geometric shape of the membrane, if necessary planar.

Another possible embodiment of the subject of the present patent, a variant given here for non-limiting and demonstrative purposes, is illustrated in sectional view in FIG. 5, in which the membrane (4) has a profile which has a single bellows around its periphery. or a multiple bellows whose profile is illustrated in section by the example figure 6.

This particular embodiment allows the bellows membrane greater ability to deform, that is, say allows the pump, subject of this patent, to have larger liquid flow rates for the same external size of the housing (1) than in the case of a single membrane of larger flat surface which would then require larger dimensions of the housing (1).

This particular embodiment allows, on the other hand, a smaller size of the pump housing, object of this patent, for the same flow rates of liquids as in the case of a single membrane of flat surface. In a variant, the return of the membrane to its initial starting position of the pump cycle can be assisted by any known or innovative system.

As a demonstration and not limitation, a variant shown in Figure 7 may provide the return of the diaphragm assisted by one or more springs (19) which may be helical or flat spiral type.

As a demonstrative and non-limiting example, in another variant illustrated in FIG. 8, the return of the membrane, when it is metallic and magnetizable, may be assisted by a magnetic field applied to it, assisted if necessary by a light central plate ( 20) fixed on the membrane and sensitive to the magnetic field.

An electrical circuit (21), which may consist of one or more coils external to the chamber (2), creates at the appropriate moment, the electromagnetic force assisting the return of the membrane to its initial position.

In a variant of the pump, object of this patent, illustrated in FIG. 9, it may be advantageous to provide a bearing surface of the membrane (4) when it is at its maximum deformation, that is to say when the difference in volume between the two lubricating and non-lubricating liquids is high and that the volume of one of the two liquids is at its maximum and then plates, by its pressure, the membrane on the bottom of the housing, which corresponds to the maximum permissible deformation of the membrane.

This support system serves as a limit support and avoids excessive deformation of the membrane (4), preventing it to exceed its modulus of elasticity when it is at its maximum deformation. This support system can be on one side (22) or the other (23) in the housing (1), or on both sides (22) and (23) in the housing (1). This support, at the bottom of one or the other chamber (2) or (3), or at the bottom of the two chambers (2) and (3), marries the exact profile on the whole surface, of the membrane (4). ), in its maximum allowable deformation; this support profile is adapted, as the case may be, to the profile of the simple membrane FIG. 9, when the membrane has a flat profile, it can be adapted to the more complex profile of a bellows membrane as indicated in FIG.

The support (s) may be an integral part of the housing or may be removable and constructed separately from the housing.

A non-illustrated variant given here, by way of demonstration and not limitation, by a particular arrangement of the pump, object of this patent, allows the pump to operate normally at high temperatures or, in other applications, at very low temperatures. low, one can use one or more temperature exchangers, such as: a heating or cooling by any known or innovative adaptable system, meeting the requirements for maintaining an average temperature within limits compatible with all components of the pump system, or only with some of them, and also adapted to the liquids of the pump object of this patent, that is to say, according to the possibilities concerning the following constituents: - The housing (1) and its membrane (4);

- the two liquids;

- The various pipes and possibly their anti-return;

- The accessory device (12). A variant, not shown, provides a maximum pressure limiter designed to prevent accidental overpressure in the circuits of the pump, object of this patent and which can be integrated: - Or to the room (2);

- Or to the room (3);

- Or to the ducts (13);

- Or ducts (5) and (7) with each their anti-return; - Or integrated in the functions of the accessory device (12);

- Or in the operation of the injection schematized by (14).

In a particular use, not illustrated, a pumping system may be composed of several interconnected pumps, each of which is in accordance with the subject matter of this patent, for practically allowing the continuous supply of a common circuit under pressure of the liquid. non-lubricant, known as the general term "common-rail".

Claims

1) Device for putting a non-lubricating liquid at a very high pressure. Characterized in that a closed housing (1), capable of withstanding without difficulty the high pressures required and in which, created cyclically by an accessory device (12), independent of this patent; the pressure variations and the volume variations of a lubricating liquid, due to the lubricant liquid introduced and then removed cydically, are transmitted thereto to a non-lubricating liquid by a metal membrane (4), which is foil-like, or any other material of same characteristics, that is to say practically without elasticity in its thickness - which passively separates - in a sealed manner and sufficiently flexible - the lubricating liquid and the non-lubricating liquid in the housing (1). The volume and the pressure of the lubricating liquid, successively introduced at the beginning of each cycle in the first chamber (2) of the casing (1) by the accessory device (12), independent of this patent, directly determine the volume and the pressure of the liquid. non-lubricant injected by the second chamber (3) of the housing (1) in the use chamber (9). One or more ducts (13) connect the first chamber (2) of the housing (1) to the accessory device (12) independent of this patent. A pipe (5), which may be provided with an anti-return valve (6), allows the non-lubricating liquid from its reservoir (10) to feed the second chamber (3) of the housing (1). Another pipe (7), which can be provided with a non-return valve (8), allows the non-lubricating liquid of the second chamber (3) of the housing (1) to be led to the enclosure of use (9) or optionally to one or more injectors (14). 2) Device according to claim 1 characterized in that the useful surface of the membrane can be: - Circular (24); Ovoid (25); - Square (26) or rectangular (27), possibly with rounded corners. 3) Device according to claims 1 or 2 characterized in that the membrane has a profile having on its periphery, a single bellows (28) or a multiple bellows (29). 4) Device according to any one of claims characterized in that the interior of the housing (1) has a shape adapted to the shape and profile of the membrane (4) which separates it into two chambers (2) and (3) ). 5) Device according to any one of the preceding claims, characterized in that the return of the membrane to its initial pump start position can be assisted by any system, known or innovative, as one or more springs (19) which can be helical or spiral flat. 6) Device according to any one of claims characterized in that the return of the membrane, when the membrane is metallic and magnetizable, may be assisted by a magnetic field applied thereto, aided if necessary by a light central plate (20). ) fixed on the membrane and sensitive to the magnetic field that an external electrical circuit (21) creates, at the appropriate time. 7) Device according to any one of claims characterized in that a bearing surface of the membrane, when it is at its maximum deformation, that is to say, plated by the pressure of the liquid on a bottom of the housing (1), either on the side of a chamber (22), or on the side of the other chamber (23), or successively on the bottom of the two chambers (22) and (23), serves as a limit support by prohibiting the membrane (4) to exceed its modulus of elasticity. This support (22) or (23), at the bottom of one or the other chamber (2) or (3) or the bottom of the two chambers (2) and (3), marries the exact profile over the entire surface the membrane in its maximum allowable deformation; this support (22) or (23) is adapted, as the case may be, to the profile of the simple membrane, when the membrane has a plane profile; it is adapted to the more complex profile of a bellows membrane. The support or supports may form an integral part of the housing (1) or be removable and constructed separately from the housing (1). 8) Device according to any one of claims characterized in that a maximum pressure limiter is intended to prevent accidental overpressure in the pump circuits, object of this patent. This pressure limiter can be: - Integrated with the first chamber (2); - Or to the second chamber (3); - Or to the ducts (5); (7); (13) causing the liquid from each of the chambers (2) and (3) of the housing (1) to come in or out; - Or integrated in the functions of the accessory device (12), independent of this patent; - Or in the operation of the injection of the chamber of use (14). 9) Device according to any one of claims characterized in that the pump can operate normally at high temperatures or, in other applications, at very low temperatures; one or more temperature exchangers can be used, for example: a heating or cooling by any known or innovative adaptable system, meeting the requirements of maintaining an average temperature within limits compatible with the constituents of the system of the pump and liquids the pump object of the present patent, that is to say, to one or more of them, and depending on the case: - The housing (1) and its membrane (4); - the two liquids; - The various pipes (5); (7); (13) and their anti-return (6); (8); - The accessory device (12), independent of this patent. 10) Device according to any one of the claims, characterized in that a pumping system can be composed of several interconnected pumps, and each one conforms to the subject of this patent, to allow, practically, the continuous feeding d a common circuit for feeding under pressure a non-lubricating liquid.