JPH0720521B2 - Control method for simulated moving bed - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for controlling a simulated moving bed in which each component in a liquid to be treated containing two or more components is individually separated. The present invention relates to a control method for controlling the flow rate of liquid supplied to and the flow rate of liquid taken out to be equal.

[Background of the Invention]

Conventionally, a simulated moving bed is known as an apparatus for continuously separating each component in a liquid to be treated containing two or more types of components.

This is an endless series connection of a number of unit-packed beds filled with a solid sorbent material having different sorption capacities for one component and another component in a liquid to be treated containing two or more components. , The liquid is circulated in one direction in the endless unit packed bed, and the liquid to be treated containing two or more components is introduced according to the flow direction of the circulating liquid, and the liquid is collected in the solid sorbent. The liquid containing a component which is difficult to be adsorbed, the eluent introduced and the liquid containing a component which is easily sorbed are taken out at intervals with respect to the endlessly connected unit packed beds, and the liquid to be treated and the eluent are separated. The respective positions for supply and removal of the liquid containing a component which is difficult to be sorbed and the liquid containing a component which is easily sorbed are intermittently moved along the flow direction of the circulating liquid.

By the way, in the simulated moving bed, if the flow rate of the liquid introduced into the circulation system and the flow rate of the liquid taken out are not equal, the pressure in the circulation system rises or conversely decreases. In order to prevent this, the flow rate of the liquid introduced into the circulation system and the flow rate of the liquid taken out must be controlled to be exactly the same, but in reality it is not possible to create a completely equal state. There is a limit to the accuracy of and it is difficult.

As conventional control methods for solving such a problem, there are JP-A-54-90072 and JP-A-60-41507.

These control methods control the flow rates of three kinds of liquids of the two kinds of liquids introduced into the circulation system and the two kinds of liquids taken out of the circulation system to set values, and circulate the flow rates of other kinds of liquids. It is controlled such that any one of the back pressures of the pump, the maximum value or the minimum value, or the average value of two or more is always constant.

However, in such a control method, since only the pressure is monitored, the original purpose is weak against the fluctuation of the flow rate caused by the pressure fluctuation when the positions of the inlet and the outlet are intermittently moved. It functions only to keep the pressure in the circulation system constant, rather than to balance the flow rate. Also, the control method is too complicated.

[Object of the Invention]

The present invention has been made to solve such a conventional problem, and is reliable even when the position of supplying liquid to the circulation system of the simulated moving bed and removing the liquid from the circulation system moves. Another object of the present invention is to provide a control method for a simulated moving bed, which controls so that the flow rate of liquid supplied to the circulation system and the flow rate of liquid taken out are equal.

[Outline of Invention]

A method for controlling a simulated moving bed according to the present invention is a unitized bed which is formed by connecting a plurality of unit-packed beds filled with a solid sorbent material in an endless series to form a circulation channel, and the unitized bed 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 the treatment liquid and the eluent, and at the same time, taking out the liquid contained in the sorbate and the liquid rich in the non-sorbate from the circulation channel to the solid sorbent are provided with the circulating liquid. In a simulated moving bed in which the positions are sequentially arranged along the flow direction and the position is intermittently moved according to a preset process, the flow rates of the two types of liquids supplied to the circulation flow path are controlled to set values, and the circulation flow is controlled. Preset flow rate for one or two liquids taken out of the channel Correct if the value on the pressure fluctuations in the circulation flow path, in which the flow rate of the liquid is taken as the flow rate of liquid supplied to the circulation flow path and controls to be constant.

Example of Invention

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

FIG. 1 shows a schematic diagram of a simulated moving bed in which the method of the invention can be effectively implemented.

In the figure, LC1 to LC12 are unit packed beds filled with a solid sorbent material, which are connected endlessly in series as shown. PR1, PR3,
PR5, PR7, PR9, and PR11 are circulation pumps, which are arranged for every two continuous unit packed beds, and circulate the liquid supplied in the unit packed beds in the arrow direction. PG1, PG3, PG5, PG7, PG9, PG11 are pressure signals P ₁ , P ₃ , P ₅ , P ₇ ,
Output P ₉ and P ₁₁ to the control device described later.

PD is a treated liquid supply pump that supplies the treated liquid D containing two or more components into the circulation flow passage, and PF is an eluent supply pump that supplies the eluting liquid F into the circulation passage. The D and the eluent F are supplied into the circulation channel at a preset flow rate.

A is a system for taking out a liquid containing a component that is easily sorbed (hereinafter referred to as sorbate liquid) R, and the sorbate taken out from the circulation channel by the sorbent liquid flowmeter FI1 provided in this system. The flow rate of the liquid R is detected and the flow rate of the sorbate liquid R is adjusted by the flow rate adjusting valve CV1. The flow rate signal F ₁ detected by the sorbate liquid flow meter FI ₁ is input to the control device, and the valve opening of the flow rate control valve CV1 is controlled by the control signal X ₁ from the control device. B is a system for taking out a liquid (hereinafter, referred to as a non-sorbate liquid) containing a component which is difficult to be sorbed, and a flow meter FI for the non-sorbate liquid provided in this system.
The flow rate of the non-sorbate liquid E taken out from the circulation channel is detected by 2 and the flow rate of the non-sorbate liquid E is adjusted by the flow rate control valve CV2. The flow rate signal F ₂ detected by the flowmeter FI ₂ for non-sorbate liquid is input to the control device, and the valve opening degree of the flow rate control valve CV2 is controlled by the control signal X 2 from the control device.

1 is a control device composed of, for example, a microcomputer,
Pressure signal from pressure detector PG1, PG3, PG5, PG7, PG9, PG11
P _1, and _{P 3, P 5, P 7} , P 9, P 11 and the flow signal F ₁ of the sorbate fluid for flow meter FI1, non-sorptive substance for liquids flowmeter FI2 flow signal F ₂ of a preset Based on the circulation system pressure target value PS, the preset flow rate target value FS _{1 of the} sorbate liquid R, and the preset flow rate target value FS ₂ of the non-sorbate liquid E,
A control signal X ₁ for adjusting the valve opening of the flow rate control valve CV1 and a control signal X ₂ for adjusting the valve opening of the flow rate control valve CV2 are output.

Next, the operation of the control device 1 will be described with reference to the block diagram used in the analog computer shown in FIG.

Drawing, AI ₁ ~AI ₉ is adder signed converter, I ₁ ~I ₅ is transcoder, II ₃ ~II ₃ integrator dated transcoder, PO1 is a potentiometer, AMP1~AMP ₃ Indicates an amplifier for determining the P band, and a pressure system controller 10 is constituted by the adders AI ₂ , AI ₃ , the integrator II ₁ and the sign converter I _3, and the adders AI ₅ , AI ₆ are also provided.
, The integrator II ₂ and the sign converter I ₄ constitute a flow rate controller 11 for the sorbed liquid, and the adders AI ₈ , AI ₉ and the integrator II ₃ and the sign converter I ₅ are non-sorbing. A liquid flow controller 12 is configured.

The pressure system controller 10 receives the pressure average value in the circulation system and the pressure target value PS in the circulation system that have been added by the adder AI ₁ and averaged by the potentiometer PO ₁ and are input to the pressure difference. A corresponding signal is sent via adder AMP ₁ to adder AI ₄ and adder AI ₇
Entered in. The flow rate target value FS ₁ of the sorbate liquid is input to the adder AI ₄ , and the corrected flow rate target value corrected by the signal from the pressure system controller 10 is used as the flow rate controller 11 of the sorbate liquid. The control signal X ₁ is output so that the flow rate F ₁ matches the corrected flow rate target value.

Similarly, the flow rate target value FS ₂ of the non-sorbate liquid is corrected by the adder AI ₇ , and the corrected flow rate target value is input to the flow rate controller 12 of the non-sorbate liquid. The control signal X ₂ is output so that the flow rate F ₂ coincides with.

That is, when the pressure in the circulation system increases, the flow rate control valve CV1, which increases the flow rates of the sorbate liquid and the non-sorbate liquid
CV2 is controlled, and conversely, when the pressure in the circulation system becomes low, the flow control valves CV1 and CV2 are controlled so as to reduce the flow rates of the sorbed liquid and the non-sorbed liquid. The flow rate of the liquid to be discharged and the flow rate of the liquid to be taken out are controlled to be equal.

Therefore, it is possible to always take out the separated liquid at a constant flow rate even if the introduction position and the take-out position of the liquid move.

In the above-described embodiment, the preset flow rate target values for the two types of liquids, the sorbate liquid and the non-sorbate liquid, are corrected according to the pressure fluctuations in the circulation passage. Controls the flow rate of one of the sorbate liquid and the non-sorbate liquid to a set value in the same manner as the two types of liquids supplied into the circulation flow path. Only the flow rate target value of the other liquid of the sorbate liquid may be corrected according to the pressure fluctuation in the circulation flow path.

〔The invention's effect〕

As described above, according to the present invention, the flow rate of the liquid supplied to the circulation flow path and the flow rate of the liquid taken out,
Even if the liquid supply position and the liquid take-out position are moved, it can be maintained constant, various components can be efficiently separated from the liquid to be treated, and its practical advantage is great.

[Brief description of drawings]

FIG. 1 shows a schematic diagram of an apparatus for carrying out the method of the present invention, and FIG. 2 shows a block diagram. 1: Controller 10,11,12: Controller LC1 to LC12: Unit packed bed PR1 to PR11: Circulation pump PG1 to PG11: Pressure detector PD, PF: Supply pump FI1, FI2: Flow rate detector CV1, CV2: Flow rate Control valves AI _{1 to} AI ₉ : Adder, I _{1 to} I ₅ : Code converter PO ₁ : Potentiometer AMP _{1 to} AMP ₃ : Amplifier

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, the flow rates of two kinds of liquids supplied to the circulation flow path are controlled to set values, and one or two kinds of liquids taken out from the circulation flow path are controlled. On the other hand, by correcting the preset flow rate target value according to the pressure fluctuation in the circulation channel, the flow rate of the liquid supplied to the circulation channel and the flow rate of the liquid taken out are controlled to be constant. Control method for simulated moving bed characterized by