ES2336177B1 - PUMP WITH DIRECT PUSH RECOVERY FOR THE IMPULSION OF FLUIDS. - Google Patents

Abstract

Pump with direct thrust recuperator for fluid drive, consisting of integrated pumping mechanisms by pistons (4) that are operated in longitudinal movement of sway, playing in each pumping mechanism the plunger corresponding (4) between two cameras (6 and 7), by one of which the passage of the fluid to be pumped is established, while in the other camera enters and exits the rejection flow of the application system, so that said rejection flow acts in direct push on the piston (4) exerting a complement action of the drive of the same.

Description

Pump with direct thrust recuperator for fluid drive

Technical sector

The object of the invention is related to the pumping of liquids in systems that have a rejection flow with an energy that can be recovered, such as desalination by reverse osmosis, proposing a pump positive displacement that includes the whole in a single unit Functional pumping and energy recovery set of rejection that is about harnessing, using said energy from rejection as a complement of direct drive thrust of the pumping.

State of the art

In the industrial field there are systems of displacement of fluids that entail a flow of rejection with a energy that can be harnessed, such as the processes of reverse osmosis desalination, in which a flow rate is supplied of salt water at a certain pressure, obtaining fresh water and a brine rejection resulting in a pressure close to that of the feed rate

In desalination by reverse osmosis is pumped 60 bar water to desalination membranes, obtaining approximately 45% fresh water and 55% brine (rejection), so that fresh water comes out without pressure (0 bar), while the rejection comes at a pressure between 1 and 1.5 bar lower than that of food, that is between 58.5 and 59 bars, leading to this rejection pressure an energy that can be harnessed.

The solutions currently used for harness the energy of the rejection flow in desalination plants, they use independent mechanisms, to act a pumping Supplementary feed:

TO)

Through Pelton turbines, which consist of pumps centrifuge, to which axis a recovery mechanism is coupled of the energy of the desalination rejection flow, so that by means of said mechanism a complementary torque is applied to the motor of the corresponding pump, which reduces the need Energy performance of the engine.

B)

Through isobaric chambers, which use the own rejection fluid to exert the necessary thrust to carry out the pumping, through a feed pump whose yield is 96-97%.

In this case, how isobaric chambers should work at 60 bars and the rejection of desalination plants goes to 58.5-59 bars, if this rejection is introduced directly on the feed pump, whose performance is of 96-97%, at its output only 58 bars are obtained; from so it is necessary to place a complementary pump that provide an increase of 2 bars, so that the power enters the isobaric chamber at the necessary 60 bars.

This provision forces the flow control supplied by the primary pump and the complementary pump, that mix in the feed, having to synchronize everything perfectly, which requires very complex controls, complicated and expensive.

It is technically admitted, on the other hand, that positive displacement systems are better performing than centrifuges, but in the current market there are no pumps positive displacement that provide large flows, so that Existing pumps of this type are not applicable in the systems of desalination

Object of the invention

According to the invention a pump is proposed positive displacement, whose realization is planned with some characteristics that allow the contribution of a large flow, therefore allowing application in systems, such as desalination and other similar, given the high performance that get.

This pump object of the invention consists of a functional set that integrates in the same structural unit the pumping system and an energy recovery system of a rejection fluid, using a plunger that is actuated by a crankshaft in scrolling game between two cameras provided with two pairs of antagonistic valves that control the closing and opening of respective inputs and outputs of said cameras, being governed those valves synchronously by it crankshaft actuator piston actuator.

A functional set is thus obtained that allows establish the passage of the fluid to be pumped through one of the chambers between the ones played by the plunger, while on the other chamber you can set the rejection flow step whose energy is about harness, so that said rejection flow energy is used to drive the advance of the plunger in the pumping action, complementing the action of the crankshaft.

In this way, the use of energy of the rejection flow is performed directly on the pump itself impulsion of the fluid to be pumped, using said flow energy of rejection as a complementary action of the pump piston, achieving a very high performance of the pumping.

In this way, with a drive energy very small outside you can get a pump with pressure necessary for reverse osmosis desalination systems, or other similar ones, taking advantage of the energy of the rejection flow itself of the system as drive pump drive energy of pumping, thus optimizing energy consumption, without the need for complicated controls such as those required by camera systems isobaric

In addition, since the recuperator acts by push, no regulation and control system is necessary to ensure the continuous balance and continuity between the flow that is it pumps with the pump and the one that is pumped by the recuperator. And by On the other hand, being the positive displacement recuperator, permanently maintains the conversion of the osmosis process Inverse, it is only necessary to act on the pumping flow if It is necessary to maintain a constant water quality, and providing more torque in the mechanical drive the progressive can be compensated increased load loss in reverse osmosis membranes with the passage of time between the cleaning processes of said membranes

The pump with direct thrust recuperator is also adapts perfectly to regime changes or revolutions, being especially suitable for working moved by variable speed drives, so that with this pump the volume of the rejection spill can be regulated at source, to the adaptation to different types of installation according to the needs, such as:

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Installation of desalination plants on the coast, with dumping of offshore rejection, where the pipes necessary involve a high cost, so that to reduce the diameter of the pipelines of the discharge pipe to the high seas, is It is necessary to return the smallest volume of rejection.

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Installation of desalination plants on the high seas, where rejections are poured directly into the sea without need of conduit pipes, the volume of the spill.

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Installation of underground desalination plants, for example under a promenade, where a large volume of rejection, so that the concentration drops and you can pour in the proximity of the coast.

The valves of the cameras between which he plays the piston of the pump are of rotary type, being acted by a common transmission that determines a demodromic distribution, constituting a synchronized system of admission and drive in each of the cameras, with synchronized relationship at the same time between the systems of both cameras.

In the assembly arrangement the piston of the pump is available with a sealing system without gasket, type ceramic, which does not require maintenance, and can be complemented with a pressure-compensated sealing system with lubrication, getting an arrangement with minimum volumetric loss and without wear

Therefore, said valve subject to invention results from certainly advantageous features, acquiring own life and preferential character, with respect to the conventional solutions, for the function to which it is destined.

Description of the figures

Figure 1 shows in perspective a practical embodiment of the pump object of the invention.

Figure 2 is a perspective from another angle, of the pump of the previous figure.

Figure 3 is a front view of the pump sectioned by the pumping body.

Figure 4 is a sectional side view of the pump assembly.

Figure 5 is a longitudinal section of a Elementary pumping mechanism of the pump.

Figures 6 and 7 represent two positions of the pumping mechanism in the suction phase.

Figures 8 and 9 represent two positions of the pumping mechanism in the drive phase.

Figure 10 is a detail of the assembly of seal-free seal of the pumping mechanism piston.

Figure 11 is a detail of the assembly of tightness with compensated pressure chamber and lubrication, of piston of the pumping mechanism.

Detailed description of the invention

The object of the invention relates to a pump intended for the impulsion of fluids in systems that produce a rejection flow with an energy that can be harnessed, such as desalination plants by reverse osmosis or similar systems, with a embodiment that includes in the same functional set the system of pumping and rejection energy recovery system.

In general, the pump of the invention it comprises, as seen in figures 1 and 2, a body (1) in the which include the pumping system and the recovery system of the energy of rejection, a body (2) in which the drive system, and a motor (3) that operates the drive

The pumping system can comprise multiple combined action mechanisms, integrated by respective pistons (4) that are operated in longitudinal displacement by a crankshaft (5) driven by the motor (3), as shown in Figures 3 and Four.

According to figure 5, each mechanism of the system pumping acts in relation to two chambers (6 and 7), among which plays the corresponding piston (4) in its displacement actuated by the crankshaft (5), so that the front part of the plunger (4) is move in one (6) of said cameras, while the back of the same piston (4) moves in the other chamber (7).

The camera (6) has an input (8) and an output (9), in which two opening valves (8.1 and 9.1) act and closing, while the camera (7) has a respective input (10) and a respective output (11), in which they act also two valves (10.1 and 11.1) opening and closing.

The valves (8.1, 9.1, 10.1 and 11.1) are of type rotary and all of them are operated in common, by means of a belt transmission (12), from the crankshaft shaft (5), so that the actuation of said valves is synchronized between them and at the same time synchronized with the movement of the piston (4) of the mechanism pumping.

Under these conditions, establishing, by For example, the passage of a fluid to be pumped, such as water Salty feed to a desalination plant by reverse osmosis, to through the chamber (6), and the passage of the system rejection flow (brine in the case of the mentioned example), through the chamber (7), when the pumping mechanism is actuated, when the piston (4) goes back, as shown in figure 6, the input (8) of the camera (6) is open and the exit (9) closed, while the camera inlet (10) (7) is closed and outlet (11) open, whereby the fluid to be pumped is sucked into the chamber (6) through the inlet (8), while the rejection fluid which is in the chamber (7) is ejected through the exit (11) of this one.

That situation remains until the plunger (4) reaches the limit of travel backwards, at which time the valves (8.1 and 11.1), which have been turning, reach the position of closure of the respective entrance (8) and exit (11), while that the valves (9.1 and 10.1), which have also been turning, reach the position to start opening the output (9) of the camera (6) and of the input (10) of the chamber (7), respectively, as see in figure 7.

When the piston (4) reaches the limit of the backward movement, its movement is reversed in forward movement, during which the entrance (8) of the chamber (6) remains closed and the output (9) open, while the input (10) of the camera (7) is kept open and the output (11) closed, as seen in figure 8.

In this phase, the piston displacement (4) causes the fluid in the chamber (6) to drive, through the exit (9), while the rejection flow arrives with the pressure it has on the chamber (7), so that the piston displacement (4), in this situation, is produced by the crankshaft action (5) and by the thrust that the rejection flow exerts in the chamber (7) on the back of the piston itself (4), so that the power of the drive to be supplied the engine (3) to the crankshaft (5) is reduced as far as the direct push action with which the rejection flow collaborates on the plunger (4).

The driving situation of the fluid to be pumped, from the chamber (6), with push collaboration by the flow of rejection, it is maintained until the piston (4) reaches the limit of the forward movement, at which time the valves (9.1 and 10.1), which have been rotating, reach the closing position of the output (9) and the respective input (10), while the valves (8.1 and 11.1), which have also been turning, reach the position to start opening the entrance (8) of the camera (6) and of the output (11) of the chamber (7), respectively, as observed in figure 9.

Thus, by scrolling in reciprocating longitudinal of the piston (4), a succession of cycles with alternating phases, suction through the inlet (8) and drive through the outlet (9), in the chamber (6), obtaining a continuous pumping of the fluid to be pumped at the same time in the chamber (7) there is a corresponding alternation of phases, arrival and evacuation of the rejection flow, taking advantage of the energy of said rejection flow to push the piston (4) as a complement to the necessary drive, thus reducing the energy that the drive motor (3) must provide, with the entire functional set, both of the system pumping, as of the energy use system of the flow of rejection, in the same structural unit.

The passage of the fluid to be pumped through the chamber front (6) and the energy use of the rejection flow in the rear chamber (7), it is a preferred form, by performance that is obtained, but without the concept of the pump as the invention is altered, the arrangement could also be conversely, since the operation is similar.

In the assembly arrangement, the piston (4) is incorporates with a sealing system (13) between the chambers (6 and 7) of the functional set of pumping and with another system of tightness (14) at the back between the chamber (7) and the body (2) of the drive mechanism, requiring between chambers (6 and 7) means of the sealing system (13) little demanding in terms of sealing, since the pressure difference between the pumping chamber (6) and the recovery chamber (7) energy of rejection, it is very small (1-1.5 pubs).

On the other hand, the plunger configuration (4) it is determined with the back that goes out towards the body (2) of the drive mechanism, with a noticeably reduced diameter in comparison with the piston (4) proper, which favors the action of the complementary thrust by the rejection flow, while that the means of the sealing system (14) are arranged in a small circumferential dimension, so the loss zone They must close is very small.

In order to minimize the problems of wear of materials caused by seawater, areas of the outer periphery of the plunger (4) that must contact the sealing systems (13 and 14), are structured with materials high hardness and corrosion resistance, such as aluminum oxide, silicon carbide, tungsten carbide, etc.

And for that same purpose, the systems of tightness (13 and 14) are structured with ceramic rings (15), as in the example of figure 10, determining a tightness partial controlled in terms of its dimensions and therefore in the percentage of leaks, which help slippage and act as a refrigerant

The sealing systems (13 and 14) can also be structured as in the embodiment of figure 11, with a ceramic ring (15) with controlled partial sealing, and a additional closure complement consisting of a double set of seals (16) with an intermediate chamber (17) that pressurizes through an external supply of lubricating fluid.

In this case the chamber (17) is pressurized to a pressure equal to or somewhat higher than the chamber pressure (7) of energy recovery of the rejection flow, bringing the level of leakage through the seal is minimal or zero.

This results in a sealing system adapted to the conditions of a very corrosive and abrasive fluid, as is sea water, leaving the responsibility of closure with respect to the exterior in charge of the boards (16) but with the lubrication of the chamber fluid (17), so that the service life of said joints (16) is similar to that achieved in the oil-hydraulic systems.

Although the description has assumed the use of the recommended pump in desalination systems by reverse osmosis, is just an example of application, not limiting, since that said pump object of the invention can be applied in the same conditions in any system that requires a fluid in movement and causing a residual flow endowed with a certain energy, such as the hydraulic drive of a turbine, from where the drive flow is dislodged to the channel of drainage with an energy that could be used to help pump the same water to the level from where the actuator flow falls of the turbine.

Claims (5)

1. Pump with direct thrust recuperator for the flow of fluids, of the type comprising one or more pumping mechanisms formed by respective pistons that are actuated in longitudinal reciprocating motion, for the impulsion of a feed fluid to a system in the that a rejection flow is provided provided with an energy that can be harnessed, characterized in that each pumping mechanism includes in the same structural and functional unit the pumping system and the energy recovery system of the rejection flow, by means of a piston (4 ) that plays between two chambers (6 and 7), through one of which the passage of the fluid to be pumped is established, while in the other chamber the rejection flow susceptible to energy use enters and exits, which exerts a direct thrust on the piston (4), acting as a complement to its actuation in the pumping action. 2. Pump with direct thrust recuperator for fluid delivery, according to the first claim, characterized in that the chambers (6 and 7), between which the piston (4) plays, have respective inputs (8 and 10) and respective outputs (9 and 11), in which corresponding rotary valves (8.1, 9.1, 10.1 and 11.1) of opening and closing act, said valves being operated in a synchronized manner by a common transmission, to determine alternate phases of admission and expulsion in the pumping chamber and alternating phases of exit and inlet of the rejection flow in the energy use chamber, in combination with the piston displacements (4). 3. Pump with direct thrust recuperator for fluid delivery, according to the first claim characterized in that the piston (4) is established with a sealing system (13) between the chambers (6 and 7) and with a system of tightness (14) of exit to the outside by the back, incorporating the sealing system (14) on a posterior extension of smaller diameter than the body of the piston that plays between the chambers (6 and 7). 4. Pump with direct thrust recuperator for fluid delivery, according to the third claim, characterized in that the sealing systems (13 and 14) of the piston (4) are determined with ceramic rings (15), establishing a partial sealing controlled by leaks that help slip and coolant. 5. Pump with direct thrust recuperator for fluid delivery, according to the third claim, characterized in that the sealing systems (13 and 14) of the piston (4) are determined with a ceramic ring (15) of controlled partial sealing , and an additional closure complement composed of a double set of seals (16), with an intermediate chamber (17) that is pressurized by external supply of a lubricating fluid.