SE452669B - PROCEDURE AND DEVICE FOR AUTOMATIC DELIVERY OF AN INJURED QUANTITY LIQUID WITH AN INJURY TEMPERATURE - Google Patents

Description

452 669 The French invention consequently operates in a cumbersome manner and causes a severe wear on the valves and their control means. SUMMARY OF THE INVENTION The object of the present invention is to improve a device and a method of the kind described in FR 2 575 806 therefor, to receive clean in a smooth manner and by only a few operating operations of the valves of the supply lines can be provided with a liquid body of the desired quantity and with the desired temperature 'without the deviation between the final temperature of the liquid body obtained in the receiver and the desired temperature being unacceptable. This object is achieved in an inventive manner by a method and a device according to the following claims 1 and 4Q, respectively. In that the device according to the invention comprises means for measuring the amount of liquid currently supplied to the receiver by the control unit being arranged to first control one of the valves to supply the receiver certain amount of liquid of a first temperature, as a measure of the measuring means, then controlling a second valve to effect a supply of liquid with a second temperature, which is likewise measured by the measuring means, while comparing the amount of heat remaining to be supplied to the receiver at any given moment. with the amount that could be supplied to the receiver if from the moment in question only the first liquid stream with the first temperature would be supplied to the receiver until the desired quantity of liquid is obtained in the receiver, and by the control unit when this comparison meets the criteria specified in claim 1 and 4 controls the second valve to be closed and the first to be opened for supplying the remaining amount of liquid, it is possible to obtain in the receiver a liquid body, the temperature of which has a slight deviation from the desired temperature, at the same time as the valve devices only need to be operated a few times. An important feature of the device according to the invention is that it is not necessary that the temperatures of the liquid streams in the various lines are known in advance exactly, nor is it necessary to know the flow of these liquid streams, but this may well be completely unknown. Thus, by the method according to the invention, it is sufficient to switch only twice between the supply of one and the other liquid stream, and this despite the fact that the exact temperatures of these liquid streams are known in advance.

BRIEF DESCRIPTION OF THE DRAWINGS The various aspects of the invention will now, by way of example only, be described with reference to the accompanying drawings in which Fig. 1 illustrates in a semi-schematic manner a liquid measurement and temperature control system according to the invention, Fig. 2 is a flow chart for the control algorithm, Figs. 3 and 4 are water heat weight diagrams of the system when in operation, Fig. 5 is a flow chart illustrating how the system may be used in a bread making plant, and Fig. 6 illustrates a modification of the system shown in Fig. 1.

DETAILED DESCRIPTION OF Dm Fönmnmcgvl Urröngunmm Fig. 1 illustrates a liquid measurement and temperature control system 1 for supplying water to a receiver 11 which is later fed to a bread dough mixer. The system 1 comprises a chamber in the form of a mixing line 2 with an inlet 2a and an outlet 2b, supply lines 3, 4 and 5 for supplying pressurized water at different temperatures to the inlet 2a of the mixing line 2 and valve means comprising solenoid valves 6, 7. and 8 for regulating the flow of water through each of the supply lines. The system 1 further comprises means in the form of a sensor 9 which is sensitive to changes in the temperature of the water in the mixing line 2 and which via a controller or control device 10 is operative to set the valves 6, 7 and 8, together with means comprising a weight sensing sensor 12 for measuring the water supplied by the chamber / mixing line 2 and which is also operative to set the valves 6, 7 and 8 via the controller 10, whereby the receiver is finally provided with a body of water of the desired quantity and temperature.

The controller 10 and the sensors 9 and 12 consist of electronic components. The controller 10 includes a conventional form of microprocessor-based single-panel computer comprising MZPU, RAM; ROM and EAROM memories, input / output devices, etc., containing a program arranged to fit the system 1. The temperature-sensitive sensor 9 consists of a high-precision platinum resistance thermometer (Gr-ade 1). The weight sensitive sensor 12 consists of a wire strain gauge based load meter.

The receiver 11 comprises a weighing vessel.

The sensors 9 and 12 are connected to the controller 10 via input signal lines 20 and 21 and generate continuous, ie pulse-free voltage outputs during operation. The solenoid valves 6, 7 and 8 are connected to the controller 10 via output control lines 22, 25, 24. The controller can be programmed using external controls (not shown). 452 '669 The water in the supply line 3 is present at "normal" or "room" temperature (say 1500). The water in line 4 is relatively hot, say 5500, and the water in line 5 is relatively cold, say 500; The temperature is not critical and need not be known to an operator. However, the required temperature of the water in the receiver 11 must be between the warmer and colder temperatures. The assumption that a batch of dough is to be mixed will work the required weight and temperature. of the water necessary for the mixture to be first noted and the controller 10 automatically connected accordingly, taking into account any previous faults as well as the required water temperature and weight.

Reference is now further made to the flow chart of Fig. 2 which shows how the operation begins (100) ° First, (101) the "normal" water control valve 6 is opened by the control device 10. Water is allowed to flow through the supply line 3 for a period of let say one second ( 102) and then the heat flux of the controller 10 is calculated as the product of the weight gain during the time period and the temperature during this time period (105) s. This heat flux value is added to the sum of total heat.If the total weight of the water discharged into the vessel 11 does not exceed the required weight (104 ) and does not exceed a certain fixed proportion of the required weight, say an eighth (106), then an additional period of time is allowed to pass and the calculations are performed electronically again When the weight of the water in the vessel 11 is equal to this proportion of the required weight (106), the temperature of the incoming water (107) is stored.If the "flag" or marking HCIN, which indicates that hot or cold water is already if not set (108) svstangs (109) the valve 6 which regulates the flow of "normal" water.

If the required temperature is now greater (110) than the stored temperature (107), hot water (111) is selected using the solenoid valve 7. On the other hand, if the required temperature is less than the stored temperature, cold water (116) is selected with using the solenoid valve Bt 452 _669 The weights and temperatures of the water continue to be measured periodically (112, 117) and total amounts of heat are calculated (115, 118) until a calculated reference point is reached (114, 119).

The basis for calculating this point, with respect to the heated web, is that the "heat to go" (required heat minus-total heat) will be less than the heat that could be introduced with "normal" water. ((Required VT weight) x normal temperature).

The basis for calculating this point, with respect to the cold water path, is that the "heat that is to go" becomes greater than the heat that could be introduced with normal water.

At this point (115, 120) the control valves 7 and 8 for hot and cold water, respectively, are closed. The program in the control device 10 is such that when the "flag" Holm is set (121), which indicates that the hot or cold water is now in, the control device causes the "normal" water control valve 6 to open again (101). The flow chart will again follow the operating path 102, 103, 104, 104, 107, 108. Upon reaching this point, the system returns to operation 102, since HCIN is now set. This loop will continue until the weight of the water in the vessel 11 reaches the required weight (104).

At this point, the "normal" water control valve 6 closes. The vessel 11 will now contain the required amount of water at the required temperature.

Figures 3 and 4 show the sum of total heat with the increase in water weight as well as the three phases of the mixture ("normal", "warm", "normal"; or "normal", "cold", "normal").

It should be noted that the system, due to its continuous accumulation of heat and storage of water at "normal" temperature after an appropriate delay, allows all constantly recurring temperature variations in the supply to be compensated while eliminating the need to remove excess water, which also wastes energy.

In summary, the water is thus fed into the weighing vessel / receiver 11 via the mixing line 2, whereby a continuous measurement of its temperature is performed by the temperature sensor 9 and a voltage proportional to its temperature is transmitted to the controller 10 via the signal line 20. 452 669.

Initially, "normal" water is selected on a fixed periodic basis and the weight of the water in the weighing vessel 11 and the temperature of the water discharged therein are read or measured. The heat present during each time period is calculated and a continuous summation of the weight and heat of the water in the vessel 11 is performed.

When the weight of the water in the vessel 11 becomes equal to a smaller proportion, say one-eighth, of the required total weight, the "normaN supply is switched off using the solenoid valve 6 and either hot or cold water is selected depending on whether the required temperature is above or below the "normalU temperature.

The second water supply is maintained until the total summed heat reaches a reference point calculated by the system. At this point, the supply of "normaP water" is reinstated. When the total weight reaches the required weight, the solenoid valves' 6, 7 and 8 are switched off.

The system has the advantageous possibility of modifying the required temperature and compensating for temperature errors in previous weighings.

As previously pointed out, the water temperatures in the supply lines 5, 4 and 5 need not be known to an operator.

The system provides for continuous measurement of the water temperature and weight and for mixing of water supplies on the basis of heat integration.

The system can use analogue circuits or digital circuits.

Three sources of feed water are preferred, although two (relatively hot and relatively cold) can be used if three cannot be provided.

A pump can be arranged in the landing line 2 if so. required and can be started and stopped by means of the control device 10.

Figures 5 and 4 are heat / weight diagrams for the system.

In Fig. 3, heat is the product of weight and temperature of the water (calories). The slope of the curve represents the temperature of the water.

During the normaN phase it can be seen that the additional heat falls below the imaginary line joining 00 and the required heat / weight point (this line obviously represents the required temperature). 452 669 Consequently heated water is selected next. This can vary in temperature and consequently The slope varies in this phase, however, it is generally steeper than the desired temperature line and it possibly crosses the line that is extrapolated back from the "target" at the "normal" water slope.At this point the heated water is switched off and "normal" "the water is turned on again.

This then proceeds to the line for the required weight.

Fig. 4 represents the sequence of events that takes place in the "normalzkyltz normal" case.

Fig. 5 is a flow chart showing how the system 1 can be used in combination with a bread dough mixer 200, a bread dough processing apparatus 201 and a baking oven 202 for producing bread 205.

The mixer 200 is preferably of the embodiment described in British Patent Application 2015562A and used in a system described by British Application 14997/77 (published as South African Patent 78/2119).

Fig. 6 illustrates a modified system 1a in which a chamber / mixing line 2 does not exist. Instead, supply lines 3, 4 and 5 supply water directly to the receiver / weighing vessel 11. In this modified system, the only temperature-sensitive sensor 9 has been replaced by three similar sensors 9a, 9b and 9c with input lines 20a, 20b respectively. 20c.

The weight sensor 12 can be replaced by other measuring means. For example, a water flow meter may be provided in the chamber / mixing line 2 to read or measure the volume of water passing therethrough and to give the controller 10 corresponding signals.

The invention is in its application not limited to measuring and temperature control of water or, certainly not to the bakery industry.

The term "set" as used in this specification obviously includes fully opening or closing the valve devices (valves 6, 7 and 8) as well as operating them so that they occupy intermediate positions between fully opened or fully closed positions.

Claims (6)

452 669 Patent claims A method of automatically delivering a desired quantity of liquid at a desired temperature by feeding a receiver with liquids of different temperatures, at least one of which is higher and one lower than the desired mixing temperature, in different streams and controlling the flows of the streams. characterized in that the liquid supply takes place in three phases, namely: a) a first phase during which a predetermined amount of liquid with a first, not necessarily exactly known temperature is fed to the receiver, the temperature of this liquid being measured, b) a second phase during which a liquid with a second, not necessarily exactly known temperature, which is on the opposite side of the temperature scale if the desired temperature against the first temperature, is fed to the receiver while measuring its temperature and the amount of liquid ÖGSS and, by knowing the amount of liquid supplied during the first phase and its temperature, thereby the amount of heat which the liquid supplied to the receiver contains the liquid, the receiver being fed with the latter liquid until the difference between the desired total amount of heat of the desired quantity of liquid and the amount of heat supplied to the receiver becomes less than the amount of heat remaining to be supplied by the liquid with the first temperature in case the first temperature is lower. than the second temperature and greater than the amount of heat remaining to be supplied by the liquid with the first temperature in case the first temperature is higher than the second temperature, c) a third phase during which liquid with the first temperature is supplied until the receiver has received the desired quantity of liquid. 452 669 A method according to claim 1, wherein the streams with different temperatures are three in number, namely one hot, one cold and one with intermediate temperature, characterized in that the liquid with the first temperature consists of the liquid stream with the intermediate temperature, and that depending on whether the desired temperature is lower or higher than the temperature of the liquid supplied to the receiver during the first phase, the cold and the hot liquid stream, respectively, are selected to constitute the liquid with the second temperature. 3. A method according to claim 2, characterized in that the liquid supplied to the receiver consists of water and the intermediate temperature corresponds to the temperature possessed by neither cooled nor heated tap water. 4. .4. Device for delivering a desired quantity of liquid with a desired temperature, comprising at least two lines (3, 4, 5) for supplying liquid streams with different temperatures to a receiver (11), wherein at least one liquid stream has a lower and at least a higher temperature than the desired one, valve means (6, 7, 8) arranged to open and restrict the supply from the respective line (3, 4, 5) to the receiver (11), a means (9) for measuring the temperature of the currently the liquid supply to the receiver, and a control unit (10) arranged to control the valve means (6, 7, 8) of the supply lines, the temperature measuring means being arranged to supply the measured temperature value to the control unit (10), characterized in that the device comprises means (12) for measuring the amount of liquid currently supplied to the receiver (11) and delivering this measured value to the control unit (10), that the control unit (10) has means for submitting data a about the desired amount and temperature of the liquid to be delivered to the receiver (11), and that the control unit (10) is arranged to, after recording this data, select a first valve device belonging to a first line with a liquid flow with a first temperature and open it while the others are closing, to close this valve device when the liquid quantity measuring means (12) has notified the control unit that a predetermined quantity of liquid has been supplied to the receiver (11), to open a second valve device belonging to a second line with a liquid stream with a second temperature located on the opposite side of the temperature scale of the desired temperature to the first temperature, to calculate from the information supplied from the temperature measuring means (9) about this second temperature the amount of heat currently remaining to be supplied to the receiver (11 ) and compare this calculated amount of heat with the amount of heat that can be supplied to the receiver in order to achieve the desired amount of liquid in the receiver. a liquid stream with the first temperature, to close the second and open the first valve device as soon as the calculated amount of heat exceeds or falls below the amount of heat that can be supplied to the receiver via the liquid stream - with the first temperature depending on whether the second temperature is lower resp . higher than the first, and closing the first valve device when the desired amount of liquid is present in the receiver (19). Device according to claim 4, characterized in that the lines (3, 4, 5) are three in number, that each line is arranged to conduct hot, cold and a liquid stream with intermediate temperature to the receiver (11), that the the first line is arranged to conduct the liquid stream with the intermediate temperature, and that the control unit (10) is arranged to compare the information it receives from the temperature measuring device (9) about the temperature of the first liquid stream with the desired temperature and to select the line with the hot or cold liquid stream as the second line depending on whether the first temperature is lower or higher than the desired one. 452 669 '11 Device according to claim 5, characterized in that the pipes (3, 4, 5) are arranged to lead water to the receiver (11), and that the first pipe (3) is arranged to lead water tap water which is neither cooled nor heated.