JPH0134040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to an automatic sugar brewing device for crystal cans used in sugar manufacturing and the like.

<Prior Art> The prior art will be explained based on FIGS. 1 and 3. FIG. 1 is a basic configuration diagram of a crystal can.

For example, as shown in FIG. 1, the sugar solution 3 to be roasted is poured into an upright crystallizer 1 having a calandria-type heating section 2 from the bottom via a regulating valve 4. Supplied. Heating steam 5
is applied to the heating section 2 in the crystal can 1 via the control valve 6. 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 7 through the valve 8. to generate crystal nuclei suitable for 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 matter 9 inside the can is discharged from the discharge valve 10. 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 adjust the concentration of white flour in the roasted sugar to an appropriate value, a difference water 11 can be supplied into the can 1 through a control valve 12. Reference numeral 13 is a hardness meter that detects the flow movement of the white bottom, and reference numeral 14 is a program controller that controls opening and closing of the sugar solution valve 4 and the differential water valve 12 based on this detection signal. The steam in the can 1 is drawn to a condenser 15 by a vacuum pump 16, and this condenser 1
5 is cooled by water 17.

18 is a pressure sensor that detects the pressure inside the can, and its output PV is led to a pressure regulator 19 as a measured value. SV is the pressure set value, MV is the adjustment output, and the opening degree of the air 22 bleed valve 21 provided in the middle of the pipe line 20 connected to the vacuum pump is controlled so that the measured value PV matches the set value SV. controlled by.

In a crystallizer having such a structure, concentration and crystal growth operations are generally performed by programmatically controlling the hardness of the bottom layer. FIG. 3 is an explanatory diagram of the operation when conventional program control is executed, and shows a part of the process of supplying a sugar solution and performing concentration in the latter half of crystal growth. (A) shows the measured value PV of the degree of vacuum inside the can, and the set value SV is maintained until time _t2 . The solid line A in (B) shows the change in the measured value e _n of the hardness meter, the dashed line B is the hardness program setting value set in steps, and the dotted line C is the hardness limit shown below that should be controlled. The set value is set in steps on this curve, which almost matches the curve. Every time the measured value of hardness matches this set value, the sugar liquid valve 3 is opened for a certain period of time and sugar liquid is supplied as shown in (C), so the hardness temporarily decreases and the sugar liquid is poured again. , and when the next set value is reached, a similar operation is performed, so that the measured value A becomes a curve that rises while each peak point remains on the curve C. When focusing on the period t ₁ and t ₂ before time t ₂ , when the measured hardness value e _n reaches the previous set value m ₀ at time t ₁ , the set value is set m ₁ higher than m ₀ by Δm. shall be. From time t ₁
At time t ₂ after T ₁ hour, the measured value of hardness is m ₁
When the set value of is reached, the set value is similarly set to m ₂ which is higher than m ₁ by Δm, and the same operation is continued thereafter. In this case, if the degree of vacuum inside the can is maintained at the set value SV, the above period T ₁ becomes almost constant, and the measured value e _n of hardness increases by stepping up the set value by Δm.
It is possible to maintain the peak at curve C and operate in the shortest possible time without degrading the quality of the crystal.

However, if the vacuum value becomes abnormal for some reason and the pressure inside the can decreases beyond the limit that can be adjusted with step 19, the hardness of the white bottom will drop significantly, so the normal step-like hardness setting will be applied. If this is continued, it takes a long time for the hardness to reach the next set value, which has the disadvantage that the hardness is significantly shifted from the hardness limit curve that should be set by the program. That is, in Fig. 3, when a disturbance occurs that causes the degree of vacuum inside the can to fall below the permissible level P _L at time _t3 ,
The measured hardness e _n is significantly reduced by this effect. Since the set value is stepped up from m ₁ to m ₂ at time t ₂ , it takes a long time for _en to reach m ₂ and reaches it at time t ₄ . From this point on, the set value increases by Δm and becomes _m3 . Therefore the measured value
The curve connecting the peaks of e _n shifts from C to C' and is significantly shifted from the limit curve C, which significantly increases the operating time and makes it difficult to obtain a product in a good crystalline state.

<Object of the Invention> The present invention provides an automatic brewing device that can programmatically control the hardness without significantly shifting the limit curve even when the degree of vacuum inside the can changes.

<Configuration of the Invention> The structural feature of the present invention is that each time the hardness of the white bottom reaches a set value, a fixed amount of differential water or sugar solution is supplied to temporarily reduce the hardness of the white bottom. In an automatic crystal can brewing device that programmatically performs an operation of lowering the set value and increasing the set value higher than the previous time, when the pressure inside the crystal can decreases below a certain value,
The setting value _{K 1 ( m 2 −} W ₂ ) (K ₁
<1) as the next hardness setting value, and set value K ₂ (m ₂ - _{m 1} ) ( _K The purpose is to further set ₂ > 1) as the next hardness setting value.

<Example> The operation of the apparatus of the present invention will be explained based on FIG. The operation up to time _t2 is exactly the same as in FIG. Constant value of allowable internal pressure at time t ₃
If it falls below P _L , the change in the measured value e _n of hardness is checked and the point in time when the rate of change of e _n reaches zero, ie the lowest level W ₂ of e _n , is stored.

Based on this memorized value, set the next firmness value m ₂₁
is set as m ₂₁ = (m ₂ −W ₂ )K ₁ (K ₁ <1) (1). m ₂ is the stiffness setting value that should be set in the next step if normal. K ₁ is smaller than 1, and the level of m ₂₁ is set to a level lower than the previous setting value m ₁ .

The white bottom is roasted sugar and concentrated toward this set value _m21 , and when this set value is reached at time _t4 , the next hardness set value _m22 is Δm′=( _m2 − _m1 )K ₂ (K ₂ > 1) (2) Set to an increased value. In this case, since K ₂ is a value larger than 1, a set value larger than the set value step Δm during normal operation is given. After the measured value of hardness reaches m ₂₂ at time t ₅ , the rising curve C' is followed by water decooking as shown in (D).
When m ₂ is exceeded, normal operation is performed, a set value m ₃ higher than m ₂₄ by Δm is given, and the same operation continues thereafter.

In the present invention, the hardness setting after the occurrence of an abnormality is made to approach the normal limit curve by using differential water decoction sugar, so the curve after returning to normal is similar to C'', which is an extension of the C curve. As a result, the length of operation time can be reduced compared to the conventional method without a large shift as in the conventional method. Also, deterioration in the quality of the crystal can be prevented.

In the above example, only the drop in can pressure is monitored and abnormal setting value processing is executed, but two conditions are considered: the drop in can pressure and the measured value of the hardness meter has fallen below a certain level. The process of the present invention may be executed when the condition is satisfied.

<Effects> As explained above, according to the present invention, the hardness program setting can be automatically changed in response to abnormal pressure inside the can, and the operating time, which is a problem with conventional setting means, can be changed. Prolongation and quality deterioration can be prevented.

In plants that use multiple crystal cans, a common vacuum pump is often used to control the internal vacuum of a crystal can, which is susceptible to fluctuations in other crystal cans, and may exceed the control capacity of the controller. Cheap. Although there is a method for manually intervening by an operator to deal with abnormal hardness settings that deal with fluctuations in the pressure inside the can, there are many cases where the abnormality is discovered too late, and the setting change operation is difficult, resulting in failure in many cases. The present invention does not have such a fear, and has the effect of significantly reducing the mental burden on the operator.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of a crystal can, FIG. 2 is an explanatory diagram of the operation of the apparatus of the present invention, and FIG. 3 is an explanatory diagram of the operation of the conventional apparatus. 1... Crystal can, 2... Heating section, 3... Sugar solution, 4... Sugar solution valve, 11... Differential water, 12... Differential water valve, 13... Hardness meter,
14...Program controller, 18...Pressure sensor, 1
9...Controller.

Claims (1)

[Claims] 1 Every time the hardness of the white bottom reaches a set value, supply a certain amount of differential water or sugar solution to temporarily lower the hardness of the white bottom and raise the set value higher than the previous time. In an automatic crystal can brewing device that performs this programmatically, when the pressure inside the crystal can decreases below a certain value, the lowest value W ₂ of the hardness of the white bottom based on this decrease and the next program under normal conditions. The set value K ₁ (m ₂ - W ₂ ) (K ₁ < 1) which is proportional to the difference in the set value m ₂ of the hardness that should be set is the next set value, and the hardness immediately before the pressure drop mentioned above is Setting value
Set value K _{2 (} m _{2 −}
m ₁ ) (K ₂ > 1) is further set as the next set value of hardness, and the operation is carried out by using differential brewing sugar until the hardness recovers to the above m ₂ due to the pressure drop. Crystal can automatic brewing device.