ITFI20120079A1 - "APPARATUS FOR CHECKING THE START-UP AND STOPPING OF A PUMP OF A WATER DISTRIBUTION NETWORK" - Google Patents

Description

â € œEQUIPMENT FOR CHECKING THE START-UP AND STOP OF A PUMP OF AN IDRI-CA DISTRIBUTION NETWORKâ €

DESCRIPTION

Technical field

The present invention relates to the field of water distribution systems and more particularly relates to an apparatus for controlling the starting and stopping of a pump in a water distribution network. State of the art

As is known, pumps are used in water distribution systems to send the water to the users. To allow adequate control of the starting and stopping of these pumps, different solutions have been developed.

One of the most used solutions is described in the European patent EP0539721. In this patent an apparatus is visible which comprises a chamber defined in a body, having an inlet duct intended to be connected to the pump delivery, and an outlet duct intended to be connected to the water mains. A non-return valve is placed in the inlet duct, while a flow switch is placed in the outlet duct. A pressure switch is instead placed in the chamber. The inlet and outlet ducts are arranged substantially vertically.

The switching on of the pump, that is the start-up, is controlled by the flow switch and the pressure switch, according to the various cases (start-up for user opening, shutdown shutdown of users, shutdown due to lack of water, system normally in operation, system in block etc.).

The pressure switch is made up of a stem fixed to an elastic membrane and is associated with a spring. The pressure of the water in the chamber pushes on the diaphragm, overcoming the force of the spring and making the stem assume a position of equilibrium. As the pressure varies, the position of the rod also changes accordingly, which can translate horizontally (each position of the rod corresponds to a different pressure value in the chamber). A magnet is placed on the stem which generates a magnetic field. The body with the chamber has a compartment separated from the chamber at the bottom of the latter. The control electronics of the equipment are located in this compartment. This electronics includes a reed device adapted to interact with the magnet of the rod (as is known, a reed device is in practice a normally open foil switch which closes when immersed in a magnetic field of a given value). In practice, the pressure in the chamber causes the rod and therefore the magnet fixed to it to assume a certain position. When the pressure drops below a certain value, for example because the utilities have been open or because there is a leak on the network, the magnet approaches the reed and hits it with its own magnetic field. As is known, the magnetic field is much stronger as one approaches the polarization axis in the magnet, so when the magnet is close to the reed to the point of investing it with the magnetic field equal to the closing value of the reed itself, the reed, closing, closes an electric circuit that controls the ignition of the pump. The restart pressure of the pump corresponds to the position of the rod that commands the closing of the reed.

The value of the restart pressure, that is the pressure at which the pump is started, is preset in the factory, for example by adjusting the axial position of the rod with respect to the spring. Once in use, this value cannot be changed. This means that in the case of systems with pressure values that are not uniform over time or differ from the design one, the restart pressure value may not be adequate for the needs. In these cases it is necessary to replace the appliance with another one with a more adequate restart pressure value. If this is not possible, there is a risk of having a pump that runs even when it is not needed or does not run when needed.

Purpose and summary of the invention

The purpose of the present invention is to solve the problems highlighted in the apparatus for controlling the starting and stopping of a pump of a water distribution network described above, and more particularly to realize an apparatus for the control of the Starting and stopping a pump in a water distribution network that is particularly flexible in its application to various types of distribution systems.

These and other purposes are achieved with an apparatus for controlling the starting and stopping of a pump in a water distribution network as per the attached claim 1.

According to the main aspect of the invention, the appliance comprises - a chamber equipped with an inlet operatively associated with the delivery of a pump and an outlet operatively connected to the water mains, - a flow switch, capable of emitting a signal start-up for the pump when a preset flow threshold value is reached,

- a pressure switch capable of emitting a start signal for the network pump when a preset value defined as â € œ restart pressureâ € is reached in this chamber;

- electronic means for controlling and managing the operation of the device; the peculiarity of the appliance is to include a plurality of preset restart pressure values stored in the electronic control and management means, and interface means available to the user to select one of the preset restart pressure values of said plurality.

In practice, the appliance according to the invention is an electronic pressure flow switch, that is a device designed to drive a water pump, turning it on and off according to the pressure conditions of the hydraulic system in which it is It is inserted and at the water flow requested by the user.

Both the system pressure and the required flow are detected with a system that detects the presence or absence of both the above parameters (pressure, flow), identifying whether they are above or below a certain threshold value. The threshold pressure is called restart pressure.

In particular, the pump is turned on in conjunction with the transition below this pressure value.

Normally, as specified above, appliances of this type, as described in EP0539721, are characterized by a single restart pressure value, which is predetermined at the factory level and maintained for the entire period of use of the appliance (e.g. example 1.5 bar).

A peculiarity of the invention is in practice that of making available to the user a set of restart pressure values, of which the user will subsequently choose one based on the conditions of his hydraulic system (for example 3 levels: 1.5, 2.0, 2.5 bar).

In a preferred form of the invention, the restart pressure is detected by means of a system comprising, in its basic elements, a magnet (mounted inside the mobile stem of the apparatus), whose position is variable along a axis, based on the system pressure, and a reed device, mounted on the electronic board of the device, whose position is fixed. During the system pressure drop phase, the magnet moves, approaching the reed: when the position is such that the magnetic field is strong enough, the reed contact closes, generating a signal that is interpreted from the electronic circuit as restart pressure, thus activating a relay that switches on the pump.

The value of the restart pressure depends on the â € œsensitivity â € of the reed contact to the field generated by the magnet; according to the invention, to vary this value one intervenes on the magnet-reed system. To achieve this goal, an embodiment provides that on the electronic board of the device according to the invention, for example, two polarizable coils or inductances (i.e. capable of generating a magnetic field) are inserted, which interact magnetically on the magnet system. reed, with the consequence of modifying the behavior of the reed itself.

In this example, the coils are placed as close as possible to the reed, in a fixed position on the electronic board; consequently the magnet remains the only moving element of the whole system.

The coils are driven by a special electronic circuit, which sets the polarization level (i.e. the intensity of the magnetic field generated) suitable to obtain the desired restart value: the higher the polarization value, the greater the effective sensitivity of the reed, and consequently also the restart pressure.

A certain level of polarization corresponds to a certain restart value, which is kept constant as long as the selection is not modified by the user; when a different value is chosen by the user, the polarization is modified bringing it to a new level. The choice of the restart pressure value, or, in the preferred embodiment, the polarization level of the coils, is performed by the user by simply pressing a button, displaying the selection for example by means of a LED indicator.

The polarization levels are predetermined during the manufacturing step, by comparison with a reference pressure sensor, and kept in the memory of the device indefinitely.

Preferably, when the appliance is powered off, the device keeps the last selection set in memory.

Brief description of the drawings

Further characteristics and advantages of the invention will become clearer from the description of a preferred but not exclusive embodiment thereof, illustrated by way of non-limiting example in the attached drawings, in which

Figure 1 represents a front view of the apparatus according to the invention;

Figure 2 is a schematic front view of the board on which the pump activation reed and the coils that regulate the sensitivity of this reed are arranged;

figure 3 represents the schematic top view of the board of figure 2, with the position of the reed activation magnet highlighted;

figure 4 represents a side view of the apparatus of figure 1, in section, in which the pump is stopped and in the chamber of the apparatus there is the maximum pressure;

figure 5 represents the view of figure 4 in which the apparatus is shown at a first restart pressure;

figure 6 represents the view of figure 4 in which the apparatus is shown at a second restart pressure;

figure 7 represents the view of figure 4 in which the appliance is shown at a third restart pressure.

Detailed description of an embodiment of the invention

With reference to the aforementioned figures, an apparatus for controlling the starting and stopping of a pump in a water distribution network is indicated as a whole with the number 10.

This device comprises a casing 11, which defines a first chamber 12 equipped with an inlet 13 operatively associated with the delivery of a pump (not shown in the figures) and an outlet 14 to be connected to the distribution network (also not shown in the figures).

The casing 11 also comprises a second chamber 15, hydraulically isolated from the first chamber 12 by a wall 16. This second chamber houses inside at least part of the electronic management and control means of the appliance, and in particular a board 17 with mounted electronic components, some of which are described below.

At the outlet 14 there is a system for detecting and / or measuring the flow of water through it, such as, in this example, a flow switch 18 of a known type, which comprises for example a slider 19 slidably arranged in the vertical section of outlet 14 and can be moved upwards by the flow of water, when present, counteracting its own weight force. When there is no flow, the spool 19 remains lowered to close the outlet 14. The head 19A of the spool has a given hydraulic seal with the outlet 14 and is dimensioned in such a way that at the sufficient pressure to overcome the weight of the slider corresponds to a minimum predetermined capacity.

The flow switch also comprises a first magnet 20A fixed on one side of the slider 19 and close to the wall 16, and a first reed switch 20B arranged on the board 17. When the flow is lower than the preset flow threshold value which allows the lifting of the slider, the magnet interacts with the reed switch, which is closed. When the slider is raised, the magnet magnetically disengages from the switch, which opens, with which a signal is generated to enable the pump to start.

On the vertical section of the inlet 13 there is a non-return valve 20 for the water from the first chamber towards the pump.

In the first chamber 12 there is a device 21 for detecting and / or measuring the pressure in the chamber itself, such as for example a pressure switch, capable of emitting a start signal for the pump when a preset value defined is reached - pressure restartâ €.

According to the invention, the apparatus 10 comprises a plurality of preset restart pressure values stored in the electronic control and management means, so that the user is able to choose, according to the needs, the value of restart pressure more suited to the real plant situation.

To choose the most appropriate restart pressure value, the appliance is equipped with interface means available to the user to select one of the preset restart pressure values of said plurality. In this example, such interface means comprise for example a panel Q arranged on the outside of the casing 11, on which selection commands and other operating indicators are available. With reference to figure 1, panel Q has three LEDs Q1 which indicate which restart pressure value is currently in use (in the specific example, 1, 5/2 / 2.5 bar) and a button Q2 which allows you to choose , with multiple presses, the most suitable value.

Preferably, this device 21 for detecting and / or measuring the pressure in the chamber 12 comprises sensor means 22, better described hereinafter, sensitive to the magnetic field and capable of producing an effect or a signal when the magnitude of the magnetic field which strikes the same sensor means, exceeds a given operating value, the value to which the restart pressure corresponds and therefore the effect or signal generated by said sensor means 22 is correlated to the actuation of the pump.

The device 21 also comprises a body 23 sensitive to the pressure in the first chamber 12, which is movable along a direction as a function of the pressure value in the same chamber 12 in such a way that a portion 23A of it approaches or moves away from the sensor means 22 on the basis of the pressure in the chamber.

For example, this body 23 is a stem constrained to translate in a predetermined direction (for example horizontal). According to a configuration of a known type per se, this stem 23 is fixed to a membrane 24 and interacts with a spring 25 in such a way that the stem is able to assume an axial position inside the chamber in function of the pressure present in the chamber. When the pressure increases, the stem is dragged by the membrane in a direction of compression of the spring 25, moving away from the wall 16 which divides the first chamber from the second chamber with the card 17 and the sensor means 22; when the pressure drops, the spring 25 pushes the stem in the opposite direction (towards the wall 16).

It should be noted how the terminal end 23A of the stem 23 is able to enter a recess 16A defined on the wall 16 which develops inside the second chamber 15; the card 17 has a through hole 17A to allow the arrangement of the recess 16A.

The device 21 for detecting and / or measuring the pressure in the first chamber also comprises magnetic means 26 integral with the portion of the stem 23 which approaches the sensor means 22. These magnetic means 26 are suitable for producing a magnetic field, hereinafter referred to as a magnetic field primary, whose field lines are indicated with the letter M1.

Preferably, the sensor means 22 can take the form of a second reed device (hereinafter also indicated with the number 22) and the magnetic means 26 into a magnet (hereinafter also indicated with the number 26), in order to which when the magnet 26 approaches the second reed device, the reed switch closes and a start signal is generated for the pump. It is clear that the value of the primary magnetic field M1 which strikes the sensor means 22, i.e. the reed device, is correlated to the pressure value in the chamber, since the position of the stem 23 with respect to the reed device 22, i.e. the distance of the magnet 26 from this reed device, it is a function of the pressure in the chamber.

Conveniently, the pressure detection and / or measurement device 21 comprises means 27 suitable for creating at least one secondary magnetic field (for example two secondary magnetic fields, but which can also be seen as components of a single secondary magnetic field), distinct from primary magnetic field produced by the magnet 26, suitable for investing the second reed device 22. Therefore this second reed device 22 is hit by at least one secondary magnetic field and, when the rod 23 moves approaching the magnet 26 to the reed, in thanks to a negative pressure variation, also from the primary magnetic field M1 generated by the magnet 26. Therefore, the operating value of the magnetic field that produces on the reed device 22 the closing of the switch and the generation of the signal / effect that allows the ™ activation of the pump, is given by the sum of the value of the secondary magnetic fields and the value of the primary magnetic field that affects the sec ondo reed device 22.

In this configuration, at each preset restart pressure value the plurality of values that can be selected by the user (in the example of the figures, three values, respectively 1.5, 2 and 2.5 bar; it goes without saying that in other examples such values may be only two or even more than three) corresponds to a correlative value of the secondary magnetic field (or secondary magnetic fields) which strikes the second reed device 22.

In practice, the presence of a secondary magnetic field modifies the â € œsensitivityâ € of the second reed device 22, that is, a lower value of the primary magnetic field (compared to the case without a secondary magnetic field) is sufficient to make it close, realizing the ™ effect / signal that activates the pump; a lower value of the primary magnetic field corresponds to a position of the magnet 26 farther away from the second reed device than in the case of absence of the secondary magnetic field, ie a position of the stem 23 corresponding to a higher restart pressure. Figures 5, 6 and 7 show the different positions of the rod 23 with the magnet 26 with respect to the second reed device 22, respectively corresponding to restart pressures equal to 2.5 - 2 - 1.5 bar. The sensitivity of the second reed device 22 is indicated in the figures by an activation area S within which the flux lines of the main magnetic field M1 of the magnet must enter. Depending on the value of the secondary magnetic field, this area S has a larger or smaller size.

Preferably, the lowest restart pressure corresponds to the case in which the secondary magnetic field is substantially zero, ie corresponding to the traditional case.

According to the preferred embodiment, the means 27 which realize the secondary magnetic field are realized in at least one coil or inductance through which electric current circulates, thus generating a magnetic field which strikes the second reed device 22. In this example there are two coils 28, arranged on the board 17 with their axis parallel to each other which generate two secondary magnetic fields; in particular they are arranged on the same side of the board where the reed is present but on opposite sides of the reed, as shown in figures 2 and 3 (for example with the reed 22 which is mainly included in the space defined between the two coil axes). The movement of the magnet is preferably orthogonal or almost orthogonal to the axis of the coils and to the board (and, preferably, orthogonal to the board).

The electronic control and management means of the appliance preferably comprise a voltage stabilizer inside the circuit (not shown), a microcontroller processing circuit, in which the management program of the whole appliance is inserted (not shown ), a user interface (the panel Q), a circuit for driving the pump (not shown), the first reed contact 20B for detecting the flow, the second reed contact 22 for detecting the pressure; a pair of coils (inductors) 28.

Conveniently, the electronic management and control means also comprise means which vary the electric current circulating for the coils 28, not described here but of a type well known to those skilled in the art. For example, these variation means can be activated by operating on the button Q2 of the panel Q. In practice, by pressing the button Q2, the current circulating for the coils and therefore the total secondary magnetic field affecting the second device is varied by means of an appropriate driving circuit. reed 22, varying the sensitivity as described above. Therefore, each restart pressure corresponds to a given value of electric current circulating for the coils (which can also be equal to â € œ0â €).

As already said, the value of the hydraulic pressure for which the second reed 22 is activated is called restart pressure; the characteristic of the appliance is to make available a set of restart pressure values, which means that the user can adjust it.

The restart pressure value depends first of all on the primary magnetic field generated by the magnet 26 (and therefore on its position with respect to the second reed device 22). According to the preferred example, the device allows you to adjust the value of the restart pressure by modifying the magnetic field that strikes the reed 22 induced by the insertion of two coils (one or more) in a position adjacent to the reed device itself .

The following describes the typical sequences of actions that are performed while using the appliance.

Standard operation, with non-polarized coils, i.e. without passing current (as if they were not present). The typical sequence of actions is as follows:

or we start from the situation in which the hydraulic system is under pressure (for example 5 bar)

o the magnet is in the â € œrest positionâ € (position A1 in figure 3);

o the polarization level of the coils is equal to L1 (preferably zero, ie no current circulates and the secondary magnetic field produced by them is zero);

o the magnetic field produced (of small value or zero) is not sufficient to activate the reed, therefore the contact is open and the pump is not activated;

o the hydraulic pressure begins to decrease, consequently the stem 23 starts to move, with the magnet 26 starting to move in the direction of the reed 22 (according to the direction z);

o when the magnet 26 reaches position A2, the reed contact closes, and the microcontroller interprets it as consent to start the pump;

o the pump restart pressure, at position A2, is called P1 (for example 1.5bar).

Operation with regulated restart pressure (with polarized coils, i.e. generating a secondary magnetic field). The typical sequence of actions is as follows:

o It starts from the situation in which the hydraulic system is under pressure (for example 5 bar);

o the magnet is in the â € œrest positionâ € A1;

o the bias level of the coils is brought to a (non-zero) value equal to L2 (L2> L1):

o the magnetic field is not in any case sufficient to activate the second reed 22), therefore the contact is open and the pump is not activated;

o the hydraulic pressure begins to decrease, consequently the magnet begins to move in the direction of the second reed 22;

o for the reed contact 22 to close, now it is sufficient for the magnet 26 to reach position A3, as the presence of the additional contribution of the secondary magnetic field generated by the coils 28 has increased the overall value of the magnetic field acting on the reed 22;

o the pump restart pressure, at position A3, is called P2 (P2> P1, for example 2 bar).

It is evident that the sequence of actions in the two cases is the same, what changes is the polarization level applied to the coils (ie the current that circulates in them and consequently the value of the magnetic field they generate).

The number of polarization levels corresponds to the number of restart pressures to be made available to the user.

The values are preloaded into the memory of the electronic media, and determined during the calibration of the device.

It is understood that what has been illustrated represents only possible non-limiting embodiments of the invention, which may vary in forms and arrangements without departing from the scope of the concept underlying the invention. The possible presence of reference numbers in the attached claims has the sole purpose of facilitating the reading in the light of the above description and the attached drawings and does not in any way limit the scope of protection.

Claims (10)

â € œEQUIPMENT FOR CHECKING THE START-UP AND STOP OF A PUMP OF AN IDRI-CA DISTRIBUTION NETWORKâ € CLAIMS 1) Apparatus for controlling the starting and stopping of a pump in a water distribution network, comprising - a chamber (12) equipped with an inlet (13) operatively associated with the delivery of a pump and an outlet (14) operatively connected to the water mains, - a system (18) for detecting and / or measuring the water flow through said outlet (14) able to emit a start signal for the pump when a preset flow threshold value is reached, - a device (21 ) for the detection and / or measurement of the pressure in said chamber (12) capable of emitting a start signal for the network pump upon reaching a preset value defined `` restart pressure '', - electronic means (17) for controlling and managing the operation of the device, characterized in that it comprises a plurality of preset restart pressure values stored in said electronic control and management means, and interface means (Q) available to the user for selecting one of the preset restart pressure values of said plurality. 2) Apparatus according to claim 1, wherein said device for detecting and / or measuring the pressure (21) in said chamber (12) comprises - sensor means (22), sensitive to the magnetic field, able to produce an effect / signal when the magnitude of the magnetic field that strikes said sensor means (22), exceeds a given operating value, said effect / signal being correlated with the € ™ operation of said pump, - a body (23) sensitive to the pressure in said chamber (12), movable along a direction as a function of the pressure value in said chamber (12) in such a way that a portion of it (23A) approaches or moves away from said means sensors (22) on the basis of the pressure in said chamber (12), - magnetic means (26) integral with said portion (23A) of mobile body, suitable for producing a magnetic field, defined as primary magnetic field (M1); the value of the primary magnetic field (M1) which strikes said sensor means (22) and is correlated to the pressure value in said chamber (12), being the position of said body (23), or the distance of said magnetic means (26) by said sensor means (22), a function of the pressure in said chamber (12). 3) Apparatus according to claim 2, wherein said sensor means (22), sensitive to the magnetic field, comprise a reed device. 4) Apparatus according to claim 2 or 3, wherein said magnetic means comprise at least one magnet (26) integral with said body (23). 5) Apparatus according to one or more of claims 2, 3 or 4, wherein said device for detecting and / or measuring the pressure (21) in said chamber (12) comprises means (28) suitable for creating at least one secondary magnetic field, distinct from the primary magnetic field (M1) produced by said magnetic means (26), suitable for investing said sensor means (22), said at least one secondary magnetic field investing said sensor means (22) with a value such as not to produce said effect /signal; the operating value that produces said signal / effect being given by the sum of the value of the secondary magnetic field that affects said sensor means (22) and of the value of primary magnetic field (M1) that affects the same sensor means (22), to each said preset restart pressure value of said plurality of values selectable by the user, corresponding to a correlative value of said at least one secondary magnetic field which strikes said sensor means (22). 6) Apparatus according to claims 3, 4 and 5, wherein said means for realizing said at least one secondary magnetic field comprise at least one coil or inductance (28) capable of generating a magnetic field which strikes said reed device (22). 7) Apparatus according to claim 6, wherein said means for realizing said at least one secondary magnetic field comprise means for varying the current circulating along said coil / inductance (28) associated with said electronic means and with said interface means (Q) on wherein there is present at least one command able to vary the quantity of said current in said at least one coil (28). 8) Apparatus according to claim 6 or 7, comprising an electronic board (17) in which said reed device (22) is arranged and at least one coil (28) generating said at least one secondary magnetic field arranged on the same side of said board ( 17) with respect to said reed device (22). 9) Apparatus according to claim 6, 7 or 8, comprising at least two coils (28) generating said at least one secondary magnetic field arranged with their polarization axes (x) parallel to each other; the polarization axis of said at least one magnet (26) being orthogonal to the plane on which the axes of said coils (28) lie; preferably the direction of movement of said at least one magnet (26) being orthogonal to the plane on which the axes of said coils (28) lie; preferably the plane on which the axes of said coils (28) lie being substantially parallel to said electronic card (17). 10. Apparatus according to claim 9, wherein said reed device (22) is included in a space defined two parallel planes on which the axes of said coils (28) lie.