JPH078321B2 - Control device for simulated moving floor - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a simulated moving bed controller for individually separating each component in a liquid to be treated containing two or more components.

(Background of the Invention) A simulated moving bed is conventionally known as an apparatus for continuously separating each component in a liquid to be treated containing two or more components.

This is an endless series connection of a plurality of unit-packed beds filled with a solid sorbent having different sorption capacities for one component and another component in a liquid to be treated containing two or more components. Then, the liquid is circulated in one direction in the endless unit packed bed, and the liquid to be treated containing two or more kinds of components is supplied in accordance with the flow direction of the circulating liquid, to the solid sorbent. The liquid containing a component that is difficult to be sorbed, the supply of an eluent, and the liquid containing a component that is easily sorbed are taken out at intervals in the endlessly connected unit packed beds, and the liquid to be treated and the eluent are treated. Of the liquid containing the component which is difficult to be sorbed and the liquid containing the component which is easily sorbed are intermittently moved along the flow direction of the circulating liquid. .

By the way, in such a simulated moving bed, in order to compensate for the pressure loss that occurs when the liquid to be treated and the eluent circulate in the endlessly connected unit packed beds, a circulation pump is installed in the circulation passage. Although it is provided, if only one circulation pump is installed, the discharge pressure of the circulation pump is the sum of the back pressure and the pressure loss of all unit packed beds, so the discharge pressure is very large. Since the unit packed bed must be a pressure vessel that can withstand this discharge pressure, multiple circulating pumps should be installed and the pressure loss in the unit packed bed should be equally shared and compensated by each circulating pump. A proposal has been made.

On the other hand, the physical properties and flow rate of the liquid flowing through each unit packed bed in the simulated moving bed are not uniform because the viscosity of the fluid changes due to the concentration change of each component in the liquid to be treated, etc. It is said that the control of the circulation pump occupies a large proportion in terms of the efficiency of component separation, because the control of the circulation pump cannot be performed under the conditions and the cavitation must be suppressed while controlling the circulation pump.

Japanese Patent Laid-Open No. 60-41507 discloses a method for controlling a circulation pump in such a simulated moving bed.

This control method is composed of four or more unit-packed beds filled with a solid sorbent and arranged in series, and the front end and the rear end are connected by a fluid passage to form an endless packed bed. Fluid in one direction, and the raw material fluid and the desorbent fluid are introduced into this circulating fluid, and at the same time, the fluid rich in non-sorbate and the fluid rich in sorbate are extracted, and the inlets for the four types of fluids are introduced. In the chromatographic separation device in which the discharge ports are sequentially arranged along the flow direction of the circulating fluid, and the positions are intermittently moved, a circulation pump equipped with a rotation speed control device between two or more unit packed beds and each circulation. A pressure detector that detects the back pressure of the pump is installed, and the flow rate of 3 kinds of fluids of the 4 kinds of liquids that are introduced into the floor and extracted is controlled to the set value, and that of the other 1 kind of fluid is controlled. Flow rate is an average of 1 or 2 or more of the back pressure of the circulation pump. Is controlled so that it is always constant, and the rotation speed of each circulation pump is individually controlled to control the flow rate of the circulating liquid and the back pressure of each circulation pump to a low level. .

That is, the rotation speed is controlled so that the circulation flow rate of one circulation pump becomes a set value, and the rotation speeds of the other circulation pumps are controlled so that the back pressure of one circulation pump installed downstream is as low as possible. Controlled.

However, in such a control method, since the back pressure is not controlled in one circulation pump that is controlling the flow rate, an abnormal increase in pressure or negative pressure may occur in the subsequent stage of this circulation pump. It is easy to raise, and when the liquid outlet comes to that position, the fluid is sucked in reverse from the outlet. In addition, when the liquid inlet came to that position, the pressure was too high and injection was difficult.

In a circulation pump that controls back pressure, the lowest pressure in the system is included in the components that make up the back pressure, so the back pressure can be adjusted no matter how the circulation pump is adjusted. It may not be possible to control to the target pressure, and it tends to become unstable due to the influence of the error in the other system internal pressure control device. In addition, the flow rate control targets only one circulation pump. The ability is slow. In order to improve this, increasing the gain of the control system (narrowing the proportional band, shortening the integration time) often leads to runaway, and it was difficult to achieve that purpose.

[Object of the Invention]

The present invention has been made to solve such a conventional problem, and is capable of properly compensating for the pressure loss of each unit packed bed and accurately and promptly controlling the flow rate. By so doing, it is an object of the present invention to provide a simulated moving bed control device capable of separating each component in the liquid to be treated with high efficiency.

[Outline of Invention]

A control device for a simulated moving bed according to the present invention is a unitized bed filled with a solid sorbent, which is connected in an endless series to form a circulation channel, and the unitized bed is provided in the circulation channel. A plurality of one circulation pumps are arranged for each one or a plurality of them to circulate the liquid in the circulation flow path in one direction, and the circulation flow path further contains two or more components. An inlet and an outlet for introducing a treatment liquid and an eluent, and at the same time taking out a liquid rich in sorbate and a liquid rich in non-sorbate from the circulation flow path to the solid sorbent In a simulated moving bed, which is sequentially arranged along the flow direction and whose position is intermittently moved according to a preset process, pressure adjusting means for adjusting the inlet pressure of each circulation pump, and a flow rate in the circulation passage. Flow rate detector to detect the pressure and inlet pressure of each circulation pump A pressure detector for detecting each, a flow rate value from the flow rate detector and a control means for individually controlling each of the pressure adjusting means using the pressure value from each of the pressure detectors as an input signal, and the control means A flow rate control signal based on a difference between the flow rate value and a preset flow rate target value, and a respective pressure control signal based on a difference between the average pressure value obtained by averaging the pressure values and the pressure values. It is characterized in that each control signal consisting of the sum of the above is output to each of the pressure adjusting means of the circulation pump corresponding to the pressure value.

Example of Invention

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 1 is a schematic view showing an embodiment of a simulated moving bed according to the present invention.

In the figure, 101 to 108 are unit packed beds filled with a solid sorbent material, which are connected endlessly in series as shown. A1 to A8 are circulation pumps, which are respectively arranged between the unit packed beds and circulate the liquid supplied in the unit packed beds in the arrow direction. RC1
RC8 are rotation speed controllers that control the rotation speeds of the circulation pumps A1 to A8, and control the rotation speeds of the circulation pumps A1 to A8 by signals from a control means described later. PG1 to PG8 are circulation pumps
A pressure detector that detects the inlet pressures of A1 to A8 inputs the detected pressure value to the control means. The FIC is a flow rate detector that detects the flow rate in the circulation flow path, and the detected flow rate is input to the control means. a is the liquid to be treated,
b is a liquid containing components that are difficult to sorb (hereinafter referred to as non-sorbate liquid), c is an eluent, d is a liquid containing components that are easily sorbed (hereinafter referred to as sorbate liquid), and In the state shown in the figure, the liquid to be treated a is introduced from the inlet side of the circulation pump A4, the non-sorbate liquid b is taken out from the discharge side of the circulation pump A6, and the eluent c is introduced from the inlet side of the circulation pump A8. ,
The sorbate liquid d is taken out from the discharge side of the circulation pump A2.

Reference numeral 1 is a control means composed of, for example, a microcomputer,
Input flow rate detector Flow rate value from FIC and preset flow rate target value and input pressure detectors PG1 to PG8
Based on the pressure detector from, the control signals for determining the individual rotation speeds of the respective circulation pumps A1 to A8 are respectively supplied to the rotation speed control device RC.
Output to 1 to RC8. The control signal output from the control means 1 is the sum of the flow rate control signal and the pressure control signal, and the flow rate control signal is the difference between the flow rate value from the flow rate detector FIC and the preset flow rate value. The pressure control signal is calculated from the pressure detection values from the pressure detectors PG1 to PG8, and the average value of the inlet pressure of all circulation pumps A1 to A8 is calculated.The average value is used as the target value for the pressure adjustment calculation. It is calculated from the difference with the pressure value.

FIG. 2 shows a basic configuration of a control circuit in the control means 1 for controlling the circulation pump A1.

F ₁ is a flow rate signal from the flow rate detector FIC, S ₁ is a predetermined flow rate set value, P _{1 to} P ₈ are pressure signals from the pressure detectors PG 1 to PG ₈ , X is a control signal, I _{1 to} I ₅ Is a code converter, AI _{1 to} AI ₆ are adders with a code converter, II _{1 to} II ₂ are integrators with a code converter, and PO _{1 to} PO ₃ are potentiometers.

Adder AI ₁ -AI ₂ Code converters I ₁ , I ₂ , integrator II ₁ , potentiometer P0 ₁ constitute a flow controller, which is calculated from the difference between the detected flow rate and the preset flow rate. The flow rate control signal is input to one of the adders AI ₃ .

On the other hand, the pressure signals P _{1 to} P ₈ from the pressure detectors PG ₁ to PG ₈ are added by the adder AI ₆ , and the total circulation pump A 1 is added by the potentiometer PO _3.
Average pressure of the inlet pressure ~A8 is determined, the average pressure of the inlet pressure and the inlet pressure P ₁ of the circulation pump A1 adder AI
Compared with _4, the pressure control signal is calculated from the difference is input to the other adders AI _3, the control signal X obtained by adding a flow control signal and the pressure control signal from the adder AI ₃ is It is output to the rotation speed control device of circulation pump A1 and RC1.

The other circulation pumps A2 to A8 are similarly added with the flow rate control signal and the pressure control signal and controlled by the control signal.

That is, since all the circulation pumps A1 to A8 have their rotation speed controlled by the control signal including the flow rate control signal, the flow rate control follows quickly and has a small error. Even if the positions for supplying and removing the liquid b, the eluent c, and the sorbate liquid d are moved to the next process position, the liquid in the circulation channel can be quickly circulated at a preset flow rate. .

In addition, the rotation speed of all circulation pumps A1 to A8 is controlled by a control signal including a pressure control signal, so that the inlet pressure of all circulation pumps can be made equal to the pressure average value, and It is possible to smoothly introduce the liquid to be treated and the eluent into and to take out the non-sorbate liquid and the sorbate liquid from the circulation channel.

Each cycle when the mixed solution of fructose and glucose was used as the liquid to be treated and water was used as the eluent to separate the fructose (sorbate liquid) and glucose (non-sorbate liquid) by the device shown in Fig. 1. Table 1 shows the pressure values of the pumps A1 to A8.

Further, in the apparatus shown in FIG. 1, each circulation pump when the same liquid to be treated and eluent are separated by the conventional control method (JP-A-60-41507) without using the control means 1. Table 2 shows the pressure values.

In the above embodiment, the flow rate and pressure are controlled by adjusting the rotation speed of the circulation pump, but as shown in FIG. 3, pressure control valves are provided on the discharge sides of the circulation pumps B1 to B8, respectively. CV1 to CV8, this pressure control valve CV1 to C
V8 may be controlled by a control signal from the control device 1, in which case each circulation pump B1 to B8 is rotated at a constant rotation speed.

Further, in each of the above embodiments, one circulation pump is provided for one unit packed bed, but one circulation pump may be provided for a plurality of adjacent unit packed beds.

〔The invention's effect〕

As described above, according to the present invention, the inlet pressure of all circulation pumps is controlled according to the fluctuation of the flow rate in the circulation flow path and the fluctuation of the inlet pressure of each circulation pump. The control followability is fast, the pressure balance can be maintained well, various components can be efficiently separated from the liquid to be treated, and the practical advantage thereof is great.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention, FIG. 2 is a block diagram, and FIG. 3 is a schematic view showing another embodiment of the present invention. 1: Control means 101 to 108: Unit packed bed A1 to A8, B1 to B8: Circulation pump PG1 to PG8: Pressure detector FIC: Flow rate detector RC1 to RC8: Rotation speed controller CV1 to CV8: Pressure control valve AI ₁ ~ AI ₆ : Adder, II ₁ , II ₂ : Integrator I ₁ ~ I ₅ : Code converter P0 ₁ ~ P0 ₃ : Potentiometer

Claims (1)

[Claims] 1. A unitized bed filled with a solid sorbent is used in an endless series to form a circulation flow path, and one or a plurality of the unitized beds are provided in the circulation flow path. 1 for each
A plurality of pedestal circulation pumps are arranged to circulate the liquid in the circulation flow path in one direction, and a liquid to be treated and an eluent containing two or more components are introduced into the circulation flow path, and the circulation is performed at the same time. An inlet and an outlet for taking out a liquid rich in sorbate and a liquid rich in non-sorbate from the flow path to the solid sorbent are sequentially arranged along the flow direction of the circulating liquid, and their positions are set. In a simulated moving bed that is intermittently moved according to a preset process, pressure adjusting means for adjusting the inlet pressure of each circulation pump, a flow rate detector for detecting a flow rate in the circulation flow path, and each circulation pump. A pressure detector for detecting the inlet pressure of each, and a control means for individually controlling each of the pressure adjusting means with the flow rate value from the flow rate detector and the pressure value from each of the pressure detectors as an input signal, The control means is A flow rate control signal based on the difference between the quantity value and a preset flow rate target value, and a respective pressure control signal based on the difference between the average pressure value obtained by averaging the pressure values and the pressure values. The control device is configured to output each control signal consisting of the sum of the above to the pressure adjusting means of the circulation pump corresponding to each pressure value.