Liq. vol. measuring and dispensing mechanism - uses light beam detector at desired level and solenoid valve reversing air flow

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Patent Board

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The Netherlands @ ATerinzagelegging 0 8400518 @ NL

Volumetric dosing device.

Int.CI⁴.G01F3 / 36.

Applicant: Herman Vanderheyden in Aalter, Belgium.

Av .: Ir. PN Hoorweg et al. Patent Office Arnold &amp; Siedsma Willemstraat 13 4811 AH Breda.

Application no. 8400518.

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Filed February 17, 1984.

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-0 Laid for inspection 16 September 1985.

The print of the description with claim (s) and any drawing (s) attached to this sheet contains deviations from the documents originally submitted; the latter can be viewed at the Patent Office upon request.

Hw / Mv / 1 Vanderheyden

Volumetric dosing device

The invention relates to a device for volumetric dosing of a liquid, consisting of a storage tank for said liquid, via a line connected to the tank for measuring temporarily a predetermined volume of liquid and a discharge line connected to the measuring vessel.

Many volumetric dosing devices are known in the art, with the disadvantage that either the dosing must take place manually, that is to say that the user must always check whether the measuring vessel contains the correct amount of liquid, after which the user must stop the supply of the liquid or a complex control equipment is required, which takes over the aforementioned function from the user. The fairly expensive control equipment can be affected, in particular with aggressive liquids, for example chlorine.

The invention has for its object to provide a dosing device of the above-mentioned type which, in addition to being highly accurate, remains reliable even with aggressive liquids and can thereby be manufactured simply and inexpensively.

The device according to the invention is distinguished in that the measuring vessel is sealed in a gas-tight manner, wherein pump means which are connected to the measuring vessel via a pressure or vacuum line and control means controlled by a level sensor are arranged for periodically successively bringing the measuring vessel under vacuum or pressure .

The invention uses the application of pressure differences in the measuring vessel to transport the liquid therein and therefrom. This makes it possible to keep all pumping and control equipment entirely outside of the liquid circuit, whereby the device is protected against the pressure

-2 aggressive effect of that liquid. The dosing device can therefore be manufactured inexpensively because the parts coming into contact with the liquid are limited, namely the supply and discharge conduit and the measuring vessel itself. The dosing can take place precisely because only the vacuum time determined by the level sensor is important.

The above-mentioned pumping means are preferably designed as a nozzle-type pneumatic pump, which pump is provided with a channel which acts as a vacuum and pressure line and communicates with the vessel, as well as an outlet channel in which a controlled valve member is arranged for closing off of that channel. With these means the measuring vessel is brought under vacuum or pressure in a particularly simple manner, because only the valve in the outlet channel has to be opened or closed.

In the preferred embodiment, the valve is connected to a floating body included in the measuring vessel. The valve is hereby directly controlled by the floating body displaceable vertically by the liquid in the measuring vessel, which displacement is transferred to the valve displacement.

The desired dosage of the liquid in the vessel can be achieved by providing the discharge pipe connected to the measuring vessel with a riser pipe that can be slid vertically through the lid. By inserting the riser pipe more or less deeper into the measuring vessel, more or less liquid is dosed per dose.

The above-mentioned and other features of the invention will be further elucidated in the figure description below of a number of exemplary embodiments.

In the drawing:

FIG. 1 a schematic overview of the device according to the invention,

FIG. 2 is a schematic overview of the measuring vessel usable in the device of FIG. 1, but provided with a pump of the nozzle type,

FIG. 3 is a schematic overview of a third embodiment of the device in which a mechanical

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-3 serving valve is installed at the pump.

The device according to Fig. 1 consists essentially of a storage tank 1, in which the liquid to be dosed is stored. This storage tank can, for example, be the commercial package, in which case provision must be made such that a pipe 2 can be brought to the bottom of the vessel 1. The line 2 leads to a measuring vessel 3, which is completely sealed in a gas-tight manner. The measuring vessel 3 is provided on the top with a closure, for example a detachable lid 4, in which a number of through-openings are accommodated, on the one hand for passing through the other end of the pipe 2. The lower end of the pipe 2 is preferably flat. passed above the bottom of the measuring vessel 3, in order to ensure a uniform inflow of the liquid into the measuring vessel 3, which prevents foaming.

A second opening serves to receive a discharge conduit 5, which is vertically adjustable in height, which is explained in more detail below. The discharge line 5 leads to any machine where the determined amount of liquid is needed. You can think of a washing machine.

The numeral 6 generally indicates the pumping control means with which the measuring vessel 3 can be filled with the liquid to be dosed or can be pressed for discharge of the liquid from the measuring vessel 3 through the discharge line 5.

The pumping and control means 6 consist of an air pump 7, the suction side of which is connected via line 8 to the upper side of the measuring vessel 3 or the cover 4, respectively. Similarly, the pressure side of the pump 7 is connected to the cover 4 via line 9. A controlled valve 10 is arranged in the vacuum or pressure line 8, 9, which valve is controlled by a level sensor 11. The level sensor 11 shown here is of the optical type, that is to say a light-sensitive member 12 is illuminated by a lamp 13 on the other side of the measuring vessel 3. The light-sensitive member 12 is connected to a solenoid via any suitable circuit 8400518 14, the core 15 of which is mounted on the slide rod of the valve 10. A compression spring 16 ensures the return of the valve 10.

The device described above works as follows.

As soon as a desired quantity of liquid has to be introduced from the storage tank 1 into the measuring vessel 3, the pump 7 is energized, which can take place by converting a switch (not shown), with which the pump 7 is connected to the electrical network. The valve 10 is in the position shown, whereby the suction side of the pump 7 is connected to the vessel via line 8. The pressure side 9 opens in the area. A vacuum is hereby brought into the measuring vessel 3, as a result of which the liquid is sucked from the storage tank 1 via the line 2 into the measuring vessel 3. As soon as the level of the liquid interrupts the light beam from lamp 13, the light-sensitive element 12 will be switched via the circuit. 13 energize the solenoid, thereby changing valve 10. As a result, the suction side of the pump 7 will be connected to the environment and the pressure line 9 to the vessel 3. The supply of liquid from the tank 1 is immediately stopped, the liquid being pushed away by the increased pressure in the measuring vessel 3 via line 5 to the place of use. It is to be noted here that the circuit 13 comprises an RC time circuit known per se, so that when the level falls down in the measuring vessel 3 no change of the solenoid 14 takes place. The time circuit is sufficient to empty the vessel 3 so that the level reaches the bottom of the riser 4. Once the liquid level 30 has reached this, further air will be blown through the line 5, so that the exact dosing of the liquid is guaranteed. The volume is of course determined by the horizontal section of the measuring vessel 3 and the distance between the bottom of the riser 5 and the level determined by the sensor 11. This distance is shown in FIG. 1 indicated by h.

As soon as the circuit 13 relaxes the solenoid 15, the spring 16 will reset the valve 10, whereby

The aforementioned first condition is obtained and the dosing can be repeated immediately if the pump 7 is not stopped.

FIG. 1 shows an alternative embodiment in which the same reference numerals are used for the same parts. The pump used in this embodiment is designed as a pneumatic pump 20 of the nozzle type. To this end, a nozzle 21 is accommodated in the pump housing, which nozzle is connected to an air line 22 which can be closed by an electric valve 23. A switch 24 provides for the actuation of the valve 23.

The pump housing is furthermore provided with a connecting channel 25 serving as a vacuum or pressure line, which channel opens into the measuring vessel 3. The discharge channel 26 associated with the pump 20 can be closed by a controlled valve 27. The valve is controlled by a solenoid 28 to be energized. and a return spring 29.

The level sensor 11 is here embodied as a body 30 that can be floated on the liquid, and a ring 31 sensing that body, which is connected to an RC circuit 32.

The embodiment shown works as follows.

By energizing the air pump 20 by opening the valve 23 after the switch 24 has been closed, a reduced pressure will arise in the measuring vessel 3 due to the blasting action, because air is discharged from this channel via the outlet 25 through the outlet channel 26. The valve 27 in this state is open.

The liquid is sucked in again via the line 2 and the level in the measuring vessel 3 will rise while taking the floating body 30. As soon as the floating body 30 has reached the ring 31, the RC circuit 32 which energizes the solenoid 28 is driven. The valve 27 is reversed, whereby the outlet channel 26 is closed. The suction action 35 of the pump 20 ceases immediately, and the air supplied via line 22 will pressurize the measuring vessel 3 via channel 25. the liquid contained therein is pushed away via the riser 5 and discharged. Once the bottom end of the 8400518

Riser line 5 has been reached, the drainage of the liquid ceases. The dosing of the liquid is therefore again determined by the height h between the ring 31 and the lower end of the riser 5. The amount of liquid to be dosed can be adjusted by moving the ring 31 along the measuring vessel 3 in the vertical sense, respectively by moving the riser 5 up and down.

It is clear that in the embodiment shown in Fig. 2 the control means have already been considerably simplified.

FIG. 3 shows an embodiment in which the same parts are indicated by the same reference numeral. In this embodiment it can be seen that the pneumatic jet pump 20 is included in the cover 4 screwed onto the vessel 3. Hereby the channels for the air pump are drilled from the material of the cover 4 and a jet pipe 21 is only inserted into the bore as a separate part mounted, opposite the bore is a thin. connecting channel 40 which leads to a valve chamber 41. At the top the valve chamber is provided with an outlet opening 42, which is connected to the outlet channel 26. In the valve chamber 41, the valve 43 is movable up and down, such that the opening 42 can be closed in the upper position. Attached to the valve 43 is a stem 44 which is connected to a floating body 45. The cover 4 is designed in such a way that it has a part 46 extending into the space of the measuring vessel 3, in which a recess 47 is arranged for receiving the floating body 45.

The embodiment shown works as follows. When air is supplied to the pneumatic pump 20 on the left-hand side of the cover 4, the air will end up in the outlet channel 26 via the channel 40. As a result of the nozzle 21, an underpressure or vacuum is generated in the vessel 3, whereby the desired liquid is drawn in from the storage tank 1. As soon as the level of the liquid has reached the floating body 45, this body 45 will move upwards with a rising liquid level, taking the valve 43 with it. The valve 43 goes up until the opening 42 8400518

7 is closed due to the upward force of the floating body 45 on the liquid. When the opening is closed, the vacuum action of the pump 20 is immediately converted into a pressure action via the channel 25 in the lid 24, so that the liquid in the measuring vessel 3 is pushed away via the riser line -5.

The lowering of the liquid level in the measuring vessel 3 has no influence on the position of the valve 43, which, due to the air pressure against the underside of the valve, continues to close the opening 42. Thus, the emptying of the measuring vessel 3 can take place as long as air pressure is supplied to the pump 20.

Pressing out stops as soon as the liquid level has reached the lower end of the riser 5. With continued supply of air, therefore, no additional liquid will be dispensed, so that the dosage remains strictly accurate to the liquid column between the underside of the floating body 45 and the underside of the riser 5. As soon as the air supply to pump 20 is stopped, the valve 43 will fall back to the drawn position under the influence of gravity, after which the dosing process can be repeated.

The accuracy and fast operation of the valve 43 is guaranteed thanks to the recess 47 in the lid which ensures that with a rising liquid level the surface of the measuring vessel 3 at the underside of the hanging part 46 is considerably reduced so that with the same liquid supply the liquid level is rapidly rises, resulting in a rapid rise of the valve 43.

In all embodiments, the non-return valve in the suction line 2 and pressure line 5 ensure that no undesired backflow of liquid takes place.

It will be clear that in the embodiments described above, all pumping and control means remain outside the actual liquid circuit. the liquid but only cause air losses because those densities are always above the liquid level in the measuring vessel 3.

If the dosing device is used in washing machines, the control of air to the pump 20 can take place simultaneously with the supply of water to the washing machine. Before the detergent or other liquid such as chlorine reaches the laundry, sufficient water has already been supplied to the washing machine to prevent damage to the laundry. After all, it takes some time for the measuring vessel 3 to be filled up and depressed.

In all embodiments, the amount of liquid to be metered can be adjusted in a very simple manner, either by moving the photosensitive member 12 in the vertical sense, including the ring 31, or moving the riser 5 in the vertical sense.

The invention is not limited to the embodiments described above.