JPS6364198B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for setting a program in an apparatus for automatically roasting sugar by programmatically controlling the hardness of the white undercoat in a crystallizer can.

<Prior art> For example, as shown in FIG. 1, the sugar solution F to be roasted is placed in an upright crystallization can 1 having a calandria-type heating section 2 through a sugar solution valve 3. It is supplied from the bottom via. Heating steam S
is applied to the heating section 2 in the crystal can 1 via the control valve 4. The sugar solution is concentrated by heating and evaporated, and at the same time, the sugar solution is replenished, and when a crystallization concentration that allows crystal precipitation is reached, seed sugar is added to the sugar solution from the feeder 5 through the valve 6. to generate crystal nuclei that reach each variety. After that, in order to prevent these crystal nuclei from combining with each other and from generating new crystal nuclei of undesired species (pseudocrystals), add water or sugar solution while monitoring the inside of the can. , continue concentration and crystal growth. When the crystals grow to a certain extent, the volume of the crystals per unit volume in the white (mixture of sugar solution and crystals) exceeds a certain value, and the crystals come quite close to each other, it becomes false. It becomes relatively difficult for crystals to form, and it is further concentrated, making it easier for crystals to grow, and by supplying sugar solution, the volume in the can increases to a certain value, and the grain size of the crystals grows to the required size. ,
The white bottom 7 inside the can is discharged from the discharge valve 8. The discharged white flour is separated into crystals and sugar solution using a centrifuge, and the sugar solution is repeatedly used to make decoction sugar. In order to obtain an appropriate concentration of white matter in the brewed sugar, differential water can be supplied into the can 1 through the differential water valve 9, and the condition inside the can 1 can be monitored through the viewing window 10. Steam in the can 1 is drawn to a condenser 11 via a valve 12 by a vacuum pump 13, and the condenser 11 is cooled by cooling water W passing through a valve 14.

Various methods have been proposed for controlling the crystal can, but a method that focuses on the hardness of the white bottom and increases this value programmatically is a control method that can realize stable operation. As shown in No. 41248, it is becoming common.

Reference numeral 15 denotes a hardness meter such as a rheometer, and a measurement signal e _n representing the hardness of the white underside is guided to the adjustment section 161 of the sequence control device 16 . 162 is the hardness setting value e _S
a program setting section 1 that supplies the adjustment section 161 with
Reference numeral 63 denotes a valve operation unit that controls opening and closing of the sugar solution valve 9 or the differential water valve 3 based on the output of the adjustment unit 161.

Although not shown in Figure 1, there are other
A level meter for measuring the level inside the can, pressure regulating means for maintaining a constant degree of vacuum inside the can, etc. are provided.

Next, a conventional program control method will be explained with reference to FIG. A is the measured value e _n and the set value e _S of the hardness in a specific area of the crystal growth process during which the sugar liquid decoction is being carried out.
B represents the opening/closing status of the sugar flow valve 3.

At time t ₁ , the measured value e _n increases and the hardness setting value
Since the sugar solution is supplied when the level of m ₁ of e _S is reached, the hardness of the white bottom is temporarily loosened. At the same time, the set value e _S is increased by Δm in steps to m ₂ . Sugar solution is supplied at time t ₂ when e _n reaches the level m ₂ of e _S again, and the same operation is continued at t ₃ , t ₄ , and so on. The curve shown by the dotted line C connecting the peak values of e _n shows the ideal limit curve for which the hardness should be programmed, and by controlling the hardness along this line, high quality crystals can be maintained and the shortest operation time can be achieved. One batch can be completed in one hour.

However, maintaining such an ideal curve C is possible when parameters such as temperature and pressure inside the can are kept constant; for example, when the amount of steam supplied changes significantly, If a disturbance occurs, such as when the pressure fluctuates significantly, it becomes difficult to maintain this ideal pattern for decocting sugar.

For example, if the amount of steam decreases abnormally after time _t4 , it will take a long time for the measured hardness value e _n to reach the next set value _m5 , and if the same setting method is continued, the hardness will decrease. The measured value changes as shown in e _n , and the slope of the curve connecting the peak values becomes smaller like C', and it deviates significantly from C. If roasting sugar is carried out under such conditions, the operating time for one batch will be significantly extended, making it difficult to obtain a high-quality crystalline product.

On the other hand, if the amount of steam increases abnormally after t ₄ , the opposite phenomenon to the above will occur, the measured value of hardness will become e _n ″, and the curve connecting the peak values will have a steep slope as shown by C″. , significantly different from C, and abnormally early.
The disadvantage is that the operation of the patch ends and the product becomes defective with many false crystals.

<Objective of the Invention> The present invention solves the problems of the conventional program control method that uses step-like setting value changes, and provides control that does not cause the measured value of hardness to deviate significantly from the limit curve in response to external disturbances. The purpose is to provide a method.

<Configuration> The feature of the method of the present invention is that when the hardness of the white bottom reaches the set value, water or sugar solution is supplied to temporarily lower the hardness of the white bottom and reduce the hardness to the above set value. In automatic brewing sugar in a crystal can, where the hardness of the white bottom is controlled programmatically by increasing the hardness, the initial value of the setting value in a specific area of the programmatic control of the hardness is the starting point and the final value is the ending point. An upper limit straight line and a lower limit straight line surrounding the hardness control limit area are determined, and the next stiffness set value after the above point is calculated by comparing the set value at the above point and the above upper limit straight line after a certain period of time has elapsed from the above point. The first straight line connecting the set value and
The second setting that maintains the set value on the above upper limit straight line.
This point is given programmatically by a straight line and a third straight line that rises along the lower limit straight line after the second straight line crosses the lower limit straight line.

<Example> Prior to describing specific examples, the concept of a new control method, which is the background of the present invention, will be explained with reference to FIG. The time point when the measured value of hardness reaches the set level m ₁ of the set value e _S at time t ₁ will be explained as a representative example. Let P ₁ be the peak point of the measured value e _n . Based on experience through various operational results, the applicant has confirmed that the limit curve is not a single one as shown in Figure 5, but that for each peak point of hardness, there is an area where the next peak point should be reached. did. This region consists of two curves starting from point _P1 , namely the upper limit curve C1 and the lower limit curve _C1 .
It is specified by the limit region R surrounded by _C2 . Strictly speaking, it was confirmed that there is an optimal pair of curves for each peak point among these two limit curves.
Therefore, when the hardness of the white bottom reaches a certain setting value,
Two curves with that point as the starting point are read from the pre-programmed memory, and the next set value is changed programmatically based on these two curves, and the peak point of the next hardness measurement value e _n is in the area. By controlling the hardness so that it falls within R, it becomes possible to maintain the measured value e _n of hardness within the limit range and advance the decoction.

Next, a specific method of program control of the set value e _S using two curves will be explained. First, when e _n reaches the set value e _S1 (hardness m ₁ ) of the previous brewing sugar cycle at P ₁ , the two curves C ₁ and C ₂ shown by dotted lines change.
When P ₁ point (time t ₁ / hardness m ₁ ) is given as the starting point, the set value for the next brewing sugar cycle is first calculated by curve C ₁
It is set as a curve that monotonically increases with time along a curve e _S21 shown by a dashed line along the curve e S21. At the point when the hardness changes by a constant value Δm from point P ₁ or when a certain time Δt has passed from point P ₁ When on C ₁ Q Along the horizontal straight line e _S22 that maintains the stiffness m ₂ at ₂₁ remains constant. The point at which this straight line e _S22 intersects the lower limit curve C ₂
When the _Q22 point is reached, the set value is set in a curve that monotonically increases with time along the lower limit curve _C2 .
This is the element that determines Q ₂₁ and Q ₂₂ points. Δm or Δt is
It is empirically set so that the predicted point of the next peak P ₂ of e _n falls on the straight line e _S22 connecting Q ₂₁ and Q ₂₂ .

Such program settings are executed every time the hardness of the underwhite area reaches a set value. The next peak P ₂ of the measured hardness value e _n is the horizontal straight line part of the program setting value
The operation corresponding to e _S22 is equivalent to the operation in which the set value is increased stepwise in the conventional method shown in FIG. However, due to changes in parameters such as temperature and pressure inside the can, the speed of roasting sugar increases and the next e _n
If the peak P ₂ of increases to hit the setting curve e _S21 along the upper limit curve C ₁ , then e _S21 increases monotonically at a level lower than m ₂ , which is different from the conventional step setting value. It has a corrective function that lowers the decoction gradient compared to the increase and shifts the next peak of e _n to the right. Conversely, if the peak P ₂ of the next e _n rises to correspond to the set curve e _S23 along the lower limit curve C ₂ due to fluctuations that delay the brewing sugar speed, e _S23
is monotonically increasing at a level higher than m ₂ and has a corrective function that increases the sugar gradient compared to the conventional stepwise increase in set value and shifts the next peak of e _n to the left.

Therefore, the peak of e _n is controlled by this correction operation so that it hits the horizontal part of the set curve, and the decoction can be automatically advanced so that the increase in hardness is within the limit region R. Even when the parameter fluctuations inside the can are quite large and last for a long time, the measured hardness value e _n is small, and it is possible to programmatically control the hardness on the upper or lower limit curve. It is possible to prevent a significant shift from the curve and the generation of defective products.

The basics of the control method explained above is to determine and provide two limit curves in real time for each peak of the measured value below the white, and to define two ideal curves for various movements of the peak point. The algorithm to do this is complex, requires the introduction of computer calculations, and the shift burden is considerable.

The present invention provides an improvement that can further simplify the setting value program setting method while maintaining the effects of the basic control method described above.

A specific method of the present invention will be explained based on FIG. First, divide the crystal growth process into multiple areas, and set the initial value of the hardness setting value in each specific area to m ₁ and the final value to
Let it be m _o . The time t ₁ when the measured value e _n of hardness reaches m ₁
The starting point is the peak P ₁ of l _n formed in , and the ending point is
A limit region R is determined by two straight lines D ₁ and D ₂ having a level of m _o . Let D ₁ be the upper limit straight line and D ₂ be the lower limit straight line. Program control of the next set value after time _t1 is executed as follows.

First, until a certain period of time Δt has passed from t ₁ , (t ₁ + Δt)
The first straight line shown by the dashed-dotted line connecting point Q ₂₁ on the upper limit straight line D ₁ at the point in time and P ₁ (coincides with D ₁ in this case)
e _S21 is given as the setting value. If the hardness level at point Q ₂₁ is m ₂ , the setting value after point Q ₂₁ is
It is given by a second straight line e _S22 shown by a dashed line that maintains the level of m ₂ constant. Next, after the point _Q22 where this second straight line intersects with the lower limit straight line _D2 , the set value is given by a third straight line _eS23 shown by a dashed line that rises in line with the second straight line. In this way, the set values after _t1 are given programmatically by the combination of the three straight lines.

Next, the measured value of hardness rises again due to the roasting sugar and coincides with the second straight line e _S22 at time t ₂ , and the peak P ₂ formed when it reaches the level of m ₂ is the setting for the next roasting sugar cycle. This is the starting point for program control of the value. In other words, the point that gives the hardness level m ₃ on the upper limit straight line D ₁ at (t ₂ + Δt) after a certain period of time Δt has passed from this time t ₂
A straight line e _S31 shown by a chain of two dots connecting Q ₃₁ and P ₂ gives the first straight line of the set value of this decoction cycle. From point Q ₃₁ , a straight line e ₃₂ shown by a two-dot chain line that maintains the hardness level m ₃ constant gives a second straight line, and from point Q ₃₂ onwards, where this second straight line intersects the lower limit straight line, the second straight line D A two-dot chain line e _S33 that rises in line with ₂ gives the third straight line.

If the point of agreement between the measured hardness e _n and the set value in this roasted sugar cycle occurs on the second straight line e _S32 as shown by R ₃ , the first straight line of the next roasted sugar cycle can be calculated using the same method. It is given as a three-dot chain line e _S41 , and the second and third straight lines are also given in the same way.

The feature of the method of the present invention lies in the function of the first straight line.
That is, for example, let's focus on the position of the peak _P2 of _en that occurs at time _t2 . Now, if the roasting sugar speed increases abnormally after t ₁ and P ₂ comes on the first straight line e _S21 , the first straight line e _S31 of the next roasting sugar cycle will also be set on the upper limit straight line D ₁ . , the slope of the first straight line is the upper limit straight line D ₁
is determined by the slope of and does not change. However, the peak
When P ₂ occurs on the second straight line e _S22 or the third straight line e _S23 , the first straight line e _S31 of the next brewing sugar cycle is
P ₂ points and the point on the first straight line at time (t ₂ + Δt)
Since it is given by the straight line connecting Q ₃₁ , the more the _two points P shift to the right, the more the first straight line e _S31 of the next cycle
The slope becomes steeper.

That is, depending on the position of the peak point in the previous brewing sugar cycle, the tendency for the brewing time to be delayed is determined by the position of point _P2 , and the slope of the set value for the next sugar brewing cycle is changed to adjust the peak point. Perform corrective action to get closer to the upper limit straight line. Generally, disturbances often occur in the direction of extending the brewing sugar time, so the correction function according to the method of the present invention effectively executes correction to the brewing sugar within the normal limit range.

FIG. 4 is a flowchart illustrating the operation of a specific process of decoction sugar by computer using the method of the present invention.
After starting the process, the initial conditions determined by the type of sugar and the zone of roasted sugar, i.e. the initial value of hardness, final value, upper limit straight line,
Read and set the lower limit straight line, Δt, etc. from an appropriate memory. Next, three straight lines are calculated to give the set values for the first sugar brewing cycle, and sugar brewing is started. Each time the measured value of the hardness meter reaches a set value, the set straight line group for the next cycle is calculated, and when the measured value of hardness reaches the final value, the process is terminated.

In the above example, program control is performed for specific areas of the roasted sugar, but if the limit area can be determined using two straight lines over the entire process of making the roasted sugar, the entire process can be controlled without dividing into multiple areas. It is also possible to apply the method of the present invention as a target.

<Effects> According to the method of the present invention described above, the following effects can be expected.

(1) Abnormal operations caused by deviations from the hardness limit due to abnormal parameters such as temperature and pressure inside the crystallizer can be significantly reduced, and operational efficiency can be significantly improved.

(2) When there is an abnormality in the parameters in the can, the settings are switched to manual and the operator continues to boil sugar manually, but it is extremely difficult even for experienced operators to return to the normal limit curve. . In the present invention, as long as the abnormal situation does not reach a fatal level, the self-correcting action automatically controls the hardness to return to the limit range without manual intervention, so that only a skilled operator can There is no need for constant monitoring, and the mental burden on the operator can be significantly reduced.

(3) To set the program, it is only necessary to provide two straight lines that define the initial value and final value of hardness and the limit area as initial conditions, and all subsequent set values are determined by the straight lines, so the program can be set. It is extremely simple, and even in the case of computer control, the burden on software is extremely small, making it possible to realize a control device at low cost.

[Brief explanation of drawings]

Figure 1 is a general configuration diagram of a sugar brewing device using a vacuum crystallizer, Figure 2 is an explanatory diagram of the basic control method that is the background of the method of the present invention, and Figure 3 is a diagram of the sugar roasting method to which the method of the present invention is applied. FIG. 4 is a flowchart illustrating the operating procedure for making roasted sugar according to the method of the present invention, and FIG. 5 is an explanatory diagram showing the conventional method for making sweetened sugar. 1...Crystal can, 2...Heating part, 3...Sugar liquid valve,
7... White bottom, 9... Difference valve, F... Sugar solution, W...
Difference water, 15...hardness meter, 16...sequence control device, 161...adjustment section, 162...program setting section, 163...valve operation section, e _n ...hardness measurement value, e _S ... Set value, _D1 ...Upper limit straight line, _D2 ...Lower limit straight line, R...Limit area.

Claims (1)

[Claims] 1 When the hardness of the white bottom reaches the set value, supply water or sugar solution to temporarily lower the hardness of the white bottom and increase the set value. In automatic brewing sugar for crystal cans in which the hardness of white bottom is controlled by a program, the hardness control limit area starting from the initial value of the hardness setting value and ending at the final value in a specific area of the hardness program control is defined. The enclosing upper limit straight line and lower limit straight line are determined, and the next hardness set value after the above point is determined by the first hardness line that connects the set value at the above point and the set value on the above upper limit straight line after a certain period of time has elapsed from the above point. A straight line, a second straight line that maintains the set value on the upper limit straight line, and a third straight line that rises along the lower limit straight line after the second straight line intersects the lower limit straight line. A method for programmatically controlling a crystal can, characterized in that the temperature is given programmatically.