WO2004018346A1

WO2004018346A1 - Liquid batching system

Info

Publication number: WO2004018346A1
Application number: PCT/TR2002/000043
Authority: WO
Inventors: Ömer YALHI
Original assignee: Yalhi Oemer
Priority date: 2002-08-26
Filing date: 2002-08-26
Publication date: 2004-03-04
Also published as: AU2002341534A1

Abstract

An integrated liquid batching system comprising an electric controlled valve suitable for serial batching of liquids in filling stations, a pulse generator which measures the liquid flow passing through said valve, an electronic control unit which is suitable for receiving signals generated by said pulse generator and on-off controlling said valve and an electronically erasable permanent memory medium which is suitable for storing batching information is disclosed. Spill liquid amounts at various flow rates are stored on said memory medium following the manufacturing process or instantly at the sight following a calibration run. Electronic control unit counts the signals originated by the pulse generator in order to measure the volume of liquid (Vcur) passing through the valve and then calculates the flow rate (Fcur). The unit compares the calculated flow rate with those stored in the said memory medium and either reads the spill volume corresponding to the calculated Fcur or makes an interpolation to determine an approximation to the actual spill volume. A microprocessor compares the sum of passed volume of liquid (Vcur) and the spill volume (Vleak) with the batch volume (Vbatch) following each pulse count and then closes the valve when said sum equals to or is greater then the desired batch volume (Vbatch).

Description

LIQUID BATCHING SYSTEM

Technical Field Of The Invention

The present invention relates to a calibrated batching system designed to operate in continuous regimes. An integrated liquid batching system comprising an electric controlled valve, an electronic control unit with a microprocessor and a water meter, a flow meter or a similar pulse generator, controls the batching process in real time and is capable of calibrating itself based on collected data. Said calibration data are stored in an electronically erasable memory medium on the control unit. These data can be loaded on said memory medium during manufacturing process as well as they can be loaded to said memory medium at the user's filling station by performing a calibration run utilizing the particular liquid proposed for mass filling in the user's end.

A batching system which enables precise and effective filling process in systems which might be accepted as "constant regimes" where slight fluctuations in the flow rate and upstream pressure occur, as well as in systems where considerable fluctuations in the same occur, is disclosed.

Background Of The Invention In many industrial fields, different types of liquids in pre-determined volumes are filled into pots or containers. Riling process of liquid products into containers is typically performed in stores of many facilities, whereas liquid products are required to be filled into containers simultaneously during manufacturing process in some facilities. As a result, it is revealed that batching process should be performed rapidly and precisely irrespective of the place and timing. Generally, electric-controlled motors or pumps are used in order to quickly fill the containers. Although rapid filling process is a requirement in view of the operational economy of an establishment, it brings the risk to of over or under filling of the containers in the accompany. Riling a container more than the predetermined amount may cause flood, contamination or result in hazardous situations. Wasting the source material is additionally a very important loss to the producer. On the other hand, filling the containers less than the predetermined amount results in utilizing the containers inefficiently and more importantiy accusation on the company for supplying the product with a quantity less than indicated amount on the container. In result, precise batching is a very important process in serial batching of liquids in filling stations. Liquid batching at the filling stations is generally realized through use of a motor- controlled valve, a flow-meter and a control interface. Among the major difficulties incurred with this type of a batching system and which generally jeopardize the accuracy of the overall batching process, one can count pressure fluctuations in the resource tank or main supply, the response/reaction time of the equipment used, the accuracy or the lag of the flow-meter. Although the system addresses the end of batching process when a signal indicating the flow of a predetermined amount through a valve, a spill amount of liquid is typically filled into the container in between the moment of receipt of the signal and the moment the valve is completely closed. Also, upstream pressure differences may further result in over or under batching as it directly affects the flow rate of liquid.

The aim of the present invention is to provide a low-cost batching system which is not affected by possible misleading pressure or flow rate fluctuations in the system, and which ensures precise filling at the filling stations with "constant-regimes" having slight fluctuations in pressure and flow rate as well as with "variable-regimes" having sharp variations in the upstream pressure and flow rate.

Prior Art A calibrated system which is designed for filling liquids in pre-determined amounts is disclosed in US 5,431,302 granted to Tulley et al. Said batching system which is especially designed for automatic-filling of beer at the bars/pubs comprises a pulse generator, a microprocessor which receives signals generated by said pulse generator and a on-off controlling valve. Microprocessor counts the signals received from said signal generator upon receipt of a "shut-off" command which is generated when the system detects the flow of predetermined amount of liquid through said pulse generator. The processor then calculates the timing at which he shall command to close said valve in order to precisely deliver predetermined amounts in the next batches. For this purpose, spill liquid volumes at each batch is monitored and each recently determined spill liquid volume is added to the previous spill liquid volumes in order to calculate average spill volume. The microprocessor then determines a new timing for sending a close command to the valve based on previously calculated average spill liquid volume and commands the valve accordingly. In a system where the source liquid is contained in a high pressure tank whose internal pressure continuously tends to decrease with frequent fluctuations, performing a real time batching calibration is essential. However, in the cases where frequent and unproportional variations in the pressure and flow rate occur, it is preferred to take average values and make corrections accordingly. Because it is possible that tiie variations in the upstream pressure and flow rate may occur gradually in a large time scale or abruptly in very short terms. Apart from long-term gradual pressure/flow rate variations, it is known that misleading pressure fluctuations in considerably short time scales may be encountered in this sort of supplies. Collecting historical values and taking average of the same may also lead to the propagation of erroneous data in the future batches as any data recorded during a misleading fluctuation will be included in the average and thus inadvertently affect almost all future batches. The aim of the present invention is to provide a high-precision batching system which covers for long-term variations as well as short term misleading fluctuations. Present invention teaches a system which monitors batched volume in real time rather than collecting historical data in order to make estimates for following batches.

The fields in which the present invention is intended to be applied are the processes with short term fluctuations in the high pressure source side like that proposed by Tulley as well as processes under "constant-regime" with gradual upstream variations in the absence of misleading short-term fluctuations. The system proposed by Tulley has the disadvantage of delivering a number of significantly erroneous batches in the presence of misleading fluctuations of constant-regimes. As short-term fluctuations may be very misleading in such flow regimes, they should be ignored to a certain extent. Further, since it is necessary to have collected a certain amount of historical data in order to operate the system, it can be said that a number of significantly erroneous batches may be delivered until enough number of historical data are available.

A similar system used in batching processes is disclosed in US 3,638,832 granted to Sauber et al. In this patent, data from a flow meter of the system is monitored and power supplied to a motor/pump of the system is decreased gradually when the volume of liquid passed through the flow-meter nears the predetermined amount. The power is completely removed when the desired amount of liquid passes through the flow-meter. One of the disadvantages of this system is the fact the process of gradually decreasing the power to the pump and removing completely when the desired amount flows through a meter is ready the exhibit different results at different flow rates and pressure ranges on the source side. Decreasing the pump power gradually typically results in different spill amounts at high and low flow rates. An additional problem is the risk of mechanical or electronic failures due to frequent alterations in the motor or pump power of the system which comprises rather expensive electronic and mechanical equipments -thus leading high operational costs and low efficient service life.

Another system relating to liquid batching process is disclosed in EP 1 132 722 of Hansen et al. Proposed system of claimed invention comprises a flow-meter, a pump or a valve and a control interface. The system makes a correlation based on the time required for reaching the constant regime after start of flow, the time required for closing the system and also changes in source pressure monitored during the flow of liquid. Although the said system seems to be similar to the batching system proposed by Tulley et al in US 5,431,301, it differs in the sense that the flow rate is monitored in real time rather than collecting historical data. As mentioned before, the system along with its high cost, has the risk of delivering erroneous batches in the case of misleading fluctuations of constant-regimes.

The aim of the present invention is to provide a low-cost batching system which is able to store its calibration data in a memory medium on an electronic control unit, and which enables instant sight calibration for updating the calibration data stored in said memory medium in order to best fit the use with a particular liquid of the sight and which is suitable for use effectively with less user intervention in filling stations with large scale variations in the flow rate and pressure.

Brief Description Of Figures

Rgure 1, shows the cross-sectional view of an integrated batch valve and control unit in accordance to the invention,

Figure 2, shows a sample work flow chart of a batching system produced in accordance to the invention.

Detailed Description Of The Invention

The invention will be described by way of presenting an example shown in Fig. 1. The flow meter (or pulse generator) is omitted in the cross-sectional view for simplicity. The liquid to be batched enters into the valve from the liquid inlet (1) located at the lower part in the Rg. 1 and leaves the valve from liquid outlet (2) to be filled into a container upon batching. The main parts forming the valve, the lower body (3) and the upper body (4) are connected to each other by means of bolts connecting the membrane. Although the type or dimensions of the valve is of no importance for application of the invention, the valve should have commutation means for adequately being controlled by an electronic control unit with a microprocessor. This type of commutation unit can be provided through use of a solenoid (6) and a pilot (5) shown on the upper body. The commutation unit and the feed card (18) which feeds the control unit and the electronic control unit, the pulse inlet channel (17) and the power inlet (16) located placed onto the case cover installed on the upper body (4). Other parts of the control unit such as membrane (20), orifice (19) and clamp (21) are used to control the liquid to be batched passing through the valve.

The control panel (9) in which controlling means and a display are located, is installed right above the shell (8) connected to the case cover (7). In the example shown in the figure 1, the control panel can freely rotate 180° around the central axis. In this way, the keyboard (14) and LCD (12) indicator can be adjusted to suit for easy visualization to the operator at the filling station. Further, it is also possible to remove the control panel (9) from the shell (8) and transfer it to a desired separate control room. In such a case, the connection of the control panel (9) with the valve and the control unit is provided by means of a cable whose one end is connected to a terminal under the control panel (9) and the other to a terminal on the shell (8). The batching system thereby enables for the establishment of remote controlling, provides the advantage of operating the batching system in environments without human beings.

A tristore card (15) located on the shell (8) converts the mains supply and provides low voltage direct current required for the operation of the electronic control unit. Use of any device which provides AC-DC conversion for the same purpose can easily be appreciated by whose skilled in the art. LCD display (12), LCD card (13) and the key board (14) on the control panel (9) which enables the operator to monitor and control the batching system, are connected on said control panel by means of an electronic card holder (10) and a frame (11). Components shown in figure 1 such as the valve, control unit, solenoid, LCD board, tristore card, membrane and clamp, are not essential features of the invention and it is obvious to those skilled in the art that various types of similar devices may be used for the same purpose.

EXAMPLE An example of the integrated batching system produced according to the invention is shown in Rg. 1 and a simplified flowchart of the software installed on the electronic control unit of said example is illustrated in g. 2. According to the example, the process the microprocessor implements at each batching process initiates with the opening of the valve. Then, pulses from a pulse generator (22), which is omitted in the figure in order to avoid complexity, is expected. A flow-meter, a water-meter or a similar device may be used a pulse generator.

Method Of Calibration:

The maximum flow-rate of the batching system is divided into 10 separate portions in this example. Spill liquid (V_)βak) volume which passes through the valve following the receipt of "shut off' command at each of these 10 portions, is stored on an electronically erasable permanent memory medium (23) (e.g. EEPROM). Measuring spill volumes at each of the flow-rates is repeated 8 times in this example and all date are transferred into a two dimensional series. Spill liquid volumes at different flow rates collected in the series are stored on said memory medium (23). Upon completion of the process, the average volume of spill liquid (Vie* ) is then calculated by taking the average of 8 measurements at each 10 distinct flow rates. Each flow rate and the average spill liquid (Vie*) volume corresponding to known flow rate are then stored on the permanent memory (23) of the batching system.

During batching process, the volume of liquid (VO*) passed through the flow-meter is determined and the flow rate (Fcur) is calculated using this value and the time elapsed. A new value for the sum of passed volume of liquid ( O,) is updated each time a pulse is received from the flow-meter (or from a pulse generator which monitors the liquid flow) and a new flow rate (Foe-) is calculated accordingly. In this system, the possibility of batching errors due to sudden pressure or flow-rate fluctuations is quite low as the total volume of liquid passing through the valve is continuously monitored whether there is a fluctuation or not. Another way of eliminating misleading fluctuations is to decrease the sensitivity to the fluctuations by way of changing the frequency of readings from the pulse generator or comparing each reading with its neighboring readings in order to detect and discard inconsistent readings.

It may be assumed that the flow rate (Fc_ur) calculated during batching will generally be inexistent within the table (recorded flow rates vs. corresponding average spill volumes) stored on the permanent memory. In this case, the volume of spill liquid (Vie*) corresponding any actual flow rate (Four) is calculated through interpolation. In this example:

( cur) Flow Rates in the Permanent (Viea Volume of Spill Liquids

Memory (It/h) corresponding the Flow Rate (It)

300 10,20

600 13,50

900 15,30

1200 17,80

1500 21,12

1800 25,63

2100 27,47

2400 33,24

2700 36,10

3000 38,96

where ; F_d : is the flow rate (found in the permanent memory ) nearest to the actual flow rate

Vc is the volume of spill liquid corresponding to F_d.

Vcur Volume of liquid passed since batching started ' cur Row rate v.** Volume of spill liquid

Vbateh Volume of liquid to be batched

If we assume that the instant flow rate during batching is F_α, = 1673 It h, the volume of spill liquid (V_)eak) may simply be calculated as follows:

V_Ieak = (21,12 x l673) / 1500 V_leak = 23,56

Since the interpolation method described above has given quite satisfactory results, this interpolation method was used in the illustrated example. It is obvious that different interpolation techniques may also be employed in order to calculate the volume of spill liquid (Vie*). Following the final reading from the meter (23), the microprocessor questions the following ;

Vcur + V|eak > Vbatch ?

and if the volume of the batch is yet not reached, the software returns to the start of the flowchart. If the above questions return a positive result, the solenoid is activated by giving "shut off" command to the valve. The sum of the volume of liquid passed from the beginning of the cycle and the volume of liquid which is going to pass until the valve is completely closed may be accepted as being equal to the batch volume with a high accuracy.

The calibration date in the example described above were determined during manufacturing process of the batching system and supplied to the user on the permanent memory of the batching system. Alternately, the software and the microprocessor of the system enables the end-user to conduct his own calibration runs utilizing his particular liquid to be filled. The calibration values of the batching system may be evaluated by the operator in the desired range of flow rates and desired number of runs. These are then stored on said electronically erasable memory and used in the batohing process.

Although the exemplified batching system produced according to the invention can be used as a compact system comprising the three fundamental units, it has the advantage of using date from external device measuring the flow and being remotely controlled. Proposed batching system enables rapid and precise fliling at serial filling stations using the advantage of his simple inexpensive structure operating based on simple routines. Since it does not require rpm modulation of a pump or a motor and/or it does not require use of a proportional valve, it has the superiority in providing long service life with high accuracy.

Claims

CLAIMS :

1.) An integrated liquid batching system suitable for serial batching of liquids comprising an electric controlled valve, a pulse generator which measures the liquid flow passing through said valve, an electronic control unit which is suitable for receiving signals generated by said pulse generator and on-off controlling said valve and an electronically erasable permanent memory medium which is suitable for storing batching information, characterized in that;

- said memory medium stores a predetermined number of values representing spill liquid amounts corresponding to predetermined flow rates of the batching system,

- said electronic control unit of the system monitors real-time signals generated by said the pulse generator in order to evaluate the volume of passed liquid (Vcur) and thereby calculates the flow rate (F_cur) in real-time, - said electronic control unit compares the calculated flow rate (Four) value with flow rate values stored on said permanent memory medium and evaluates the spill liquid volume corresponding the calculated flow rate by way of an interpolation in between the stored values and the calculated flow rate,

- a microprocessor of the unit compares the sum of passed volume of liquid (Vcur) and the calculated volume of spill liquid (Viea with the batch volume (V_baω,) following each reading and then commands the valve to close when the former equals to or is greater then predetermined batch volume (Vbat*).

2.) The integrated liquid batching system as set forth in Claim 1 wherein said pulse is a flow-meter.

3.) The integrated liquid batching system as set forth in Claim 1 wherein a cable connection is installed in between a terminal under the control panel and a terminal on the shell in order to establish remote control of the batching system.

4.) The integrated liquid batching system as set forth in Claim 1 wherein the calibration date on the permanent memory medium is erasable and re-writable when an operator of the system performs a series of calibration runs in desired flow rates and with desired liquids.

5.) The integrated liquid batching system as set forth in any of the preceding claims wherein the control panel of the system freely rotates 180° around its center axis.

6.) The integrated liquid batching system as set forth in any of the preceding claims wherein the system comprises a keyboard on the control panel suitable for entering batching date.

7.) The integrated liquid batching system as set forth in any of the preceding claims wherein the system comprises an indicator panel on the control panel to display the batching date.

8.) The integrated liquid batching system as set forth in any of the preceding claims wherein the batching liquid is water.