JPH0779719B2 - Sugar liquid filter flow controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to improvement of flow rate control in a filtration process in a sugar factory.

<Prior Art> An example of flow rate control in the cleaning step will be described with reference to FIG.
Reference numeral 1 is a magma mixer, and 2 is a sugar washing separator that cuts out raw sugar in the magma mixer into a low liquor tank 3. W and R are sweet water and redissolved sugar solution supplied to the low liquor tank 3.

4 is the level sensor of the low liquor tank, PV ₁ is the measured value. 5 is a level controller, measured value PV
The level of the low liquor tank is controlled to the set value by operating the sugar wash separator 2 with the operation output MV ₁ that controls and calculates the deviation between ₁ and the set value SV ₁ .

The sugar solution output from the low liquor tank is the first flow rate control means.
Guided by C ₁ . In this flow rate control means C ₁ , 6 is a flow rate sensor, PV ₂ is its measured value, 7 is a control valve, 8 is a flow rate controller, and an operation output that controls and calculates the deviation between the measured value PV ₂ and the set value SV _2. MV ₂ is supplied to the control valve 7. Reference numeral 9 is a selector for supplying the set value SV ₂ of the sugar liquid flow rate.

The sugar solution output from the first flow rate control means passes through the carbonate satiety tank 10 after the lime milk has been added, and is guided to the satiety solution tank 11 after the satiety process is executed. 12 is the level sensor of the saturable liquid tank, and PV ₃ is its measured value. The sugar solution output from the saturable liquid tank is guided to the second flow rate control means C ₂ .

In the second flow rate control means C ₂ , 13 is a flow rate sensor PV ₄
Is a measured value, 14 is a control valve, 15 is a flow controller, and an operation output MV ₄ that controls and calculates the deviation between the measured value PV ₄ and the flow set value SV ₄ from the selector 16 is supplied to the control valve 14. Adjust the flow rate to the set value SV ₄ .

The sugar solution output from the second flow rate adjusting means passes through the primary filter 17 and is guided to the brown liquor tank 18. 19 is a brown liquor tank level sensor, and PV ₅ is its measured value. The output sugar solution of the brown liquor tank is guided to the third flow rate control means C ₃ .

In the third flow rate control means C ₃ , 20 is a flow rate sensor PV ₆
Is a measured value, 21 is a control valve, 22 is a flow controller, and is an operation output that controls and calculates the deviation between the measured value PV ₆ and the flow set value SV _6.
Supply MV ₆ to the control valve 21 to adjust the flow rate, and set the flow rate to the set value S
Adjust to V ₆ .

The output sugar liquid of the third flow rate control means C ₃ passes through the bone charcoal adsorption tower 24 for decolorization and is guided to the decoloring tank 25.

Further, the sugar solution output from the decoloring tank is sent to the crystallization step through a processing step such as a ceramic filter means, an ion exchange resin tower, and a condensing can as necessary.

Each element of each process described above may be called by another name by the factory.

Reference numeral 26 is a means for setting the amount of dissolved sugar, and sets the amount of sugar to be treated by weight. 27 is a capacity conversion means, which converts the weight set value W _s into the flow rate set value F _s .

Reference numeral 28 denotes an addition means, which adds the flow rate setting value F _s to the flow rate measurement value PV _R of the return sugar solution R to the low liquor tank to transmit the flow rate setting value F _o .

29,30,31 are the 1st, 2nd, 3rd which inputs the flow rate set value F _o in common
It is a brix correcting means, and the first flow rate set value F _c1 and the second flow rate set value are obtained by multiplying F _o by the brix measured value BX.
F _c2 and 3rd flow rate set value F _c3 are respectively set to the 1st, 2nd and 3rd selectors.
Send to 9,16,23.

In normal operation, these selectors select the first flow rate set value F _c1 , the second flow rate set value F _c2 , and the third flow rate set value F _c3, and respectively select the first flow rate control means C ₁ and the second flow rate control. Means C ₂ ,
Supply to the first flow rate control means C ₃ .

With such a configuration, the set value of the amount of dissolved sugar is supplied to the first flow rate control means C ₁ , the second flow rate control means C ₂ , and the first flow rate control means C ₃ simultaneously in parallel.

Next, other input signals of the selectors 9, 16 and 23 will be described.

In addition to the set value F _c1 , the selector 9 outputs the level measurement value PV ₁ of the low liquor tank 3 and the output PV ₃ ′ of the function calculating means 32.
Is input and the minimum signal of the three is the set value SV ₂
Is selected as. The function calculating means 32 has a characteristic that the measured value PV ₃ of the level sensor 12 of the saturable liquid tank is input, and when PV ₃ approaches 100%, its output is reduced.

Therefore, the selector 9 selects PV ₁ or PV ₃ ′ when the level of the low liquor tank 3 falls below a certain value or when there is a risk of overflow of the saturated liquid tank 11, respectively, and selects the cascade set value SV of the flow rate. _It has the function of ₂ .

In addition to the set value F _c2 , the selector 16 is supplied with the level measured value PV ₃ of the saturable liquid tank 11 and the output PV ₅ ′ of the function calculating means 33, and the smallest signal of the three is the set value SV ₄ Is selected as. The function calculation means 33 has a characteristic that the measured value PV ₅ of the level sensor 19 of the brown liquor tank is input, and its output is reduced when PV ₅ approaches 100%.

Therefore, the selector 16 controls the PV ₃ or PV ₅ ′ when the level of the saturated liquid tank 11 drops below a certain value or when the brown liquor tank 18 is in danger of overflowing, respectively.
Has the function of selecting the flow rate cascade setting value SV ₄ .

The selector 23 inputs the set value F _c3 , the level measurement value PV ₅ of the brown liquor tank 18 and the output PV ₇ ′ of the function calculating means (not shown) in the next step, The smallest of them is selected as the setpoint SV ₆ . The function calculating means of the next stage has a characteristic that the measured value PV ₇ of the level sensor of the tank of the next stage is input, and when PV ₇ approaches 100%, its output is reduced.

Therefore, when the level of the brown liquor tank 18 drops below a certain level or when there is a risk of overflow of the tank in the next stage process, the selector 23 respectively sets PV ₅ or PV ₇ ′.
Has the function of selecting the flow rate cascade setting value SV ₆ .

With such a configuration, normally, the flow rate control based on the set value of the sugar liquid amount is executed by the first to third flow rate control means,
When the tank level at the front stage of each flow rate control means decreases or when there is a risk of overflow of the tank level at the next stage of each control means, the cascade control is automatically switched to the cascade control by the measured value related to the tank level. Short circuit or overflow is prevented.

<Problems to be Solved by the Invention> The means such as the primary filter 17 or the ceramic filter in the subsequent stage in the flow rate control in the cleaning process described above is usually realized in a multi-stage parallel configuration, and therefore is provided in the front stage of each filter. The flow rate control means is realized by a plurality of parallel adjusting means corresponding to each filter. Therefore,
As for the load distribution of each adjusting means, if the capacity of each filter is equal, the total flow rate set value from the selector may be evenly distributed to each adjusting means. When the above flow rate setting is made, the filtration pressure becomes high, the filter is damaged, the flow rate control as a whole becomes impossible, and there is a risk of overflow of the upstream tank and short circuit of the downstream tank.

An object of the present invention is to provide a sugar solution filter flow rate control device capable of solving such problems.

<Means for Solving Problems> A structural feature of the present invention is that a plurality of stages of parallel configuration filter means provided during the cleaning process and a plurality of stages of parallel configuration provided corresponding to these filter means are provided. Flow rate control means, and distribution setting means for supplying a distribution set value based on the total filter liquid flow rate set value to the plurality of flow rate control means,
Required amount calculation for calculating the required amount from the total of the measured values of the low flow rate control group having a negative deviation between the average value of the flow rate control means and the distribution set value and the total filter flow rate set value Means and the demand amount are supplied to the distribution setting means so that the distribution set value of the flow rate control group having a high capability in which the deviation is not negative is increased.

<Operation> According to the present invention, the total filter liquid flow rate set value is distributed and set to the flow rate control means of the multiple-stage parallel configuration provided corresponding to each filter means, and the average of the measured values of each flow rate control means is set. The required amount is calculated from the total of the measured values of the low flow rate control group having a negative deviation from the distribution set value and the total filter liquid flow rate set value, and the requested amount is supplied to the distribution setting means to obtain the deviation. Allocate the increase to the distribution set value of the flow control group having a high non-negative capacity.

<Example> An example of the present invention will be described with reference to FIG. In this embodiment, the second filter for controlling the flow rate of the primary filter in FIG. 2 is used.
It is applied to the flow rate control means, and the same components as the components described in FIG. 2 are denoted by the same reference numerals and the description thereof will be omitted.

17 _1, 17 ₂ ... 17 _n is a plurality of stages connected in parallel primary filter, 13 _1, 14 ₁ is the flow rate sensor and control valve corresponding to the filter 17 _1. 15 ₁ , 15 ₂ ... 15 _n are flow controllers corresponding to the respective filters, and the controller 15 ₁ is a sensor 13 ₁
The difference between the measured value PV ₄₁ and the set value SV ₄₁ is calculated, and the operation output MV ₄₁ is transmitted.

The total filter flow rate set value SV ₄ transmitted from the selector 16 is the distribution setting means 32 ₁ corresponding to each filter,
It is supplied to 32 ₂ ... 32 _n, and the flow rate set values SV ₄₁ , SV ₄₂ ... SV _4n suitable for the processing capacity of each filter are calculated, and the selector 35
_It is supplied to and held by the set value holders 36 ₁ , 36 ₂ ... 36 _n via ₁ , 35 ₂ ... 35 _n . The selectors 35 ₁ , 35 ₂ ... 35 _n have set values SV _L1 , SV for limiting the upper limit of the distribution set values.
_L2 ... SV _Ln are given.

Flow controller 15 ₁ , 15 ₂ ... 15 _n each operation output MV ₄₁ , MV ₄₂ ... MV
_4n is supplied to the selectors 37 ₁ , 37 ₂ ... 37 _n and compared with the operation outputs MV ₈₁ , MV ₈₂ ... MV _{8n of} the pressure controllers 38 ₁ , 38 ₂ ... 38 _n , and the operation output of the flow controller increases. If it exceeds the operation output of the pressure controller, the opening of the control valve is controlled by the operation output of the pressure controller, and the input fluid of the primary filter is controlled to a constant pressure, which prevents damage due to the application of excessive pressure to the filter. ing. SV ₈₁ is the pressure setting for the pressure adjusting meter 38 ₁ are given the same settings for other pressure controller.

39 ₁ , 39 ₂ ... 39 _n are moving average calculators, and controllers 15 ₁ , 15
₂ ... 15 measurements PV ₁ from _n, PV ₂ ... enter the PV _n, transmits the moving average PV _1, PV ₂ ... PV _n of a period of time of each measurement value, the required amount computing unit 40 ₁ this, Supply 40 ₂ ... 40 _n .

The required amount calculator inputs the average calculation output from the moving average calculator and the flow rate set values SV ₁ , SV ₂ ... SV _n of each filter from the set value holders 36 ₁ , 36 ₂ ... 36 _n and the required amount DM Is calculated and supplied to the distribution setting means 32 ₁ , 32 _2, ... 32 _n .

The distribution setting means 32 is composed of the passage filter information generating means 33 ₁ , 33 ₂
... 33 liquid passing filter information f ₁ from _n, f ₂ ... enter the f _n and the calculated demand DM, distribution setting to load sharing increases the flow rate setting value of the high capacity filter is executed.

Next, an example of the requested amount and distribution setting calculation will be described. When the capacity of the filter decreases, the set value with respect to the set value decreases, and the deviation (measured value-set value) increases in the negative direction.

The required amount calculator 40 ₁ , 40 ₂ ... 40 _n monitors the deviation of the moving average of the set value of the controller corresponding to each filter and the measured value, and reduces the capacity of the filter whose deviation is below a negative fixed value. Therefore, the sum of the moving averages of the flow rate measurement values of the filter with reduced capacity is subtracted from the total filter flow rate set value SV ₄ and the required amount D
Calculate M and send to distribution setting means.

In the distribution setting means, the one having a non-negative deviation among the passage filters is considered to have high capacity (there is more room to flow), and the required flow rate is obtained by dividing the required amount DM by the number of filters having high capacity. Add to the flow rate setting value of the filter to decrease, and reduce the flow rate setting value of the filter whose capacity has decreased.
Appropriate set values are distributed so that SV ₄ is set as a whole.

As described above, for the filter in which the operation output to the control valve is increased by such distribution control, the selector 37
₁ , 37 ₂ ... 37 _n selects the operation output of the pressure controller,
The filter is under constant pressure control, and destruction is prevented.

The above embodiment is an example in which the present invention is applied to the flow rate control means of the primary filter, but it can be applied to other filter means in the cleaning step as well.

Furthermore, the constant pressure control loop of the filter by the pressure regulator is not an essential requirement and can be omitted.

<Effects of the Invention> As described above, according to the present invention, the flow rate control of a multi-stage filter is performed by load distribution without increasing the filtration pressure even if there is a variation in the capacity of each filter, thus controlling the total flow rate. Can be performed, and the controllability of the entire cleaning process can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part showing an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an example of a conventional technique. 1 ... Magma mixer, 2 ... Sugar wash separator, 3 ... Low liquor tank, 4, 12, 19 ... Level sensor, 5 ... Level controller,
6,13,20… Flow sensor, 7,14,21… Control valve, 8,15,22…
Flow controller, 9,16,23… Selector, 10… Carbonate filling tank, 1
1 ... Carbonated satiety tank, 17 ... Primary filter, 18 ... Brown liquor tank, 24 ... Bone charcoal adsorption tower, 25 ... Decoloring tank,
26 ... Sugar amount setting means, 27 ... Solution conversion means, 28 ... Addition means, 29, 30, 31 ... Brix correction means, C ₁ , C ₂ , C ₃ ... First,
Second and third flow rate control means, 32 ... Distribution setting means, 35, 37 ... Selector, 36 ... Set value holding means, 38 ... Pressure controller, 39 ...
Moving average calculator, 40 ... Demand calculator

Claims (1)

[Claims] 1. A plurality of stages of parallel configuration filter means provided in a cleaning process, a plurality of stages of parallel flow rate control means provided corresponding to these filter means, and a total filter for the plurality of flow rate control means. Distribution setting means for supplying a distribution set value based on the liquid flow rate set value, and a measured value of a low flow rate control group having a negative deviation between the average of the measured values of the flow rate control means and the distributed set value. A demand amount calculating means for calculating a demand amount from the total and the total filter liquid flow rate setting value, and a demand setting amount supplying means for supplying the demand amount to the distribution setting means to obtain a distribution set value of a flow rate control group having a high capability in which the deviation is not negative. A sugar liquid filter flow rate control device characterized by increasing the share.