JPS6157058B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid mixing device used for mixing fluids from a plurality of inlet channels and shipping the mixture to a lorry or transferring it to another tank, and particularly relates to The present invention relates to a device that controls the mixing ratio of fluids in an inlet channel according to the properties of the fluids.

For example, it has been proposed to mix multiple types of petroleum and automatically change the mixing ratio of the petroleum in the inflow passage so as to maintain the sulfur content of the mixed petroleum at a constant level. In this conventionally proposed method, the sulfur content in the mixed petroleum is detected, and based on this value, the flow rate of the fluid in each inlet channel, and its sulfur ratio, a computer is used to set the ratio setting controller for each inlet channel. Calculating the ratio. Although such control can be performed accurately, it is expensive because it uses an electronic computer. We also proposed an integral deviation control method that compares the integral product of the flow rate and detected sulfur with the integral product of the flow rate and the target sulfur value, and controls the flow rate ratio of the inflow channel according to the deviation. has been done. Since this method is based on integral value control, the time constant is large, and this method has the disadvantage that hunting is likely to occur. Furthermore, a sampling control method has been proposed, but this method requires changing the sampling period every time the flow rate or ratio is changed, making the change cumbersome.

An object of the present invention is to provide a fluid mixing device that can be constructed at a relatively low cost, is less prone to hunting, and is easy to handle.

According to this invention, each inlet flow path is provided with a ratio setting controller that controls the flow rate of the fluid, and the properties of the fluid flowing through the mixing flow path, such as sulfur, octane number, and clay, are detected, and the detected values are instantaneously transmitted. The operating property controller performs adjustment calculations with the set value, the controller output and the master pulse are multiplied by a multiplier, and the multiplication output is supplied to the ratio setting controller in the input flow path as the master pulse. In this way, since an instantaneous action controller is used without using an expensive electronic computer, hunting does not occur because the control time constant is relatively small, and furthermore, when changing the flow rate of mixed fluid or changing the set value of properties. Easy to operate.

Next, an embodiment of the fluid mixing device according to the present invention will be described with reference to the drawings.

Figure 1 shows the case of mixing five component fluids.
Each fluid is supplied to the inlet channels 11 to 15,
The fluids in the inlet channels 11 to 15 are supplied to a common mixing channel 16 and mixed with each other. Each inlet channel 11
-15 are provided with flow meters 17-21, respectively, to detect the flow rate of the fluid flowing through the flow path, and each detected flow rate is input to ratio setting controllers 22-26. Each controller 22 to 26 has a changeover switch 2.
A master pulse is input from 7 to 31, the pulse is multiplied by the ratio setting value set to each controller 22 to 26, and the multiplied output pulse and the flow rate signal from the corresponding flow meter are used for adjustment calculation. is,
Based on the calculation results, the control valves 32 to 36 inserted into the inlet channels 11 to 15 are controlled, and the inlet channels 11 to 15 are controlled.
15 to the mixing channel 16 are mixed at a set ratio.

In this embodiment, when petroleum is mixed and a sulfur component is detected as a property of the mixed fluid in the mixing channel 16, a sulfur detector 37 is attached to the channel 16, and its detection output is detected by a calculator 38. The amount of sulfur is calculated. This calculated amount of sulfur is adjusted and calculated in the property controller 39 with the sulfur set value from the terminal 41. This property controller 39 operates at least instantaneously.

Furthermore, in this embodiment, when the dead time of the sulfur detection system in the mixing flow path 16 is relatively large, the dead time compensation circuit 42 performs compensation calculation for the controller 39.

The output of the property controller 39 and the master pulse from the terminal 43 are multiplied by multipliers 44 and 45. In this embodiment, feedback control can be selectively performed on one or more of the inlet channels 11 to 15, and various types of control can be selected. That is, each switching terminal a of the switches 27 to 31 is connected to the terminal 43, and when connected to this terminal a, the switch operates as a normal ratio mixing device without any feedback control. The switching terminal b of the terminals 27-31 is connected to the output side of the multiplier 45, and when connected to this terminal, the output pulse of the multiplier 45 is supplied to each controller 22-26 as a master pulse. Switch 27-31
The switching terminal c is connected to the output side of the multiplier 44,
Further, the switching terminal d is connected to the output side of the adding circuit 47. Each detected flow rate signal from the flowmeters 17 to 21 is inputted to the adding circuit 47, and a pulse proportional to the sum thereof is outputted. Therefore, when the switches 27 to 31 are connected to the terminal d, the mixture is mixed at the set ratio with respect to the actual flow rate. The switches 27 to 31 can be independently set to any of the switching terminals a to d. The output of the adder circuit 47 is also supplied to a batch controller 48. This controller 4
8 is controlled by a batch sequencer 49 to send a master pulse to a terminal 43 so that only a predetermined amount can be shipped.

The pressure of the fluid is measured by a pressure gauge 51 in the mixing flow path 16.
The detected pressure is input to a pressure regulator 52 and adjusted and calculated with the set pressure, and the output of the regulator 52 is converted into a pulse signal by a current pulse converter 53. When the terminal 43 is switched from the batch controller 48 to the pulse converter 53 side by the switch 54 and the switches 27 to 31 are connected to the terminal a, the inlet channels 11 to 1
The flow rate of 5 is controlled to maintain the set mixing ratio.

As the dead time compensation circuit 42, a known one can be used. For example, as shown in FIG.
A first-order lag (time constant) T is set between 0 and 2 minutes and inputted from the terminal 56, and a dead time L including the entire flow path and control loop is set and inputted between 0 and 10 minutes. , compensation coefficient (sensitivity) from terminal 57
_K1 is set and input between 0 and 2 minutes. Furthermore, the output MV of the controller 39 and the set value (sulfur target value) SP of the controller 39 are input, and E=1−e〓/1+TS
(S is a Labrasian operator) and SP' = SP - K ₁ E are performed, and as a result, SP' is input to the controller 39 as a compensation value, and an adjustment calculation is performed using this SP' as a set value. It will be done.

When the input, that is, the amount of detected sulfur, matches the target value, the property controller 39 outputs, for example, the center of the output change range of the controller 39. In other words, in the case of an output of 4 to 20 mA, if the input matches the target value, it will output 12 mA, and on the other hand, it can be changed by 50% to the positive side or to the negative side.

In the multipliers 44 and 45, when the output i of the controller 39 is 12 mA, that is, 50%, the input and output pulses are 1:1, and for each input master pulse P ₀ of the multipliers 44 and 45, each output pulse P ₁ and P ₂ are set as follows.

P ₁ = P ₀ {100+1(i-50)} = P ₀ (i+50) P ₂ = P ₀ {100+1(i-50)} = P ₀ (150-i) When the target value SP is smaller than the measured value PV When the controller output i increases, i>50 and P ₁ >P ₂ . Conversely, when SP>PV and i decreases, i<50 and P ₁ <P ₂ . Therefore, when SP<PV,
Since it is sufficient to increase the amount of low-sulfur oil and decrease the amount of high-sulfur oil, the output _P1 of the multiplier 44 is used as a master pulse for low-sulfur concentration oil, and a large amount of this low-sulfur concentration oil is flowed, and the output P of the multiplier 45 is increased. ₂ is used as a master pulse for high sulfur concentration oil to flow less high sulfur concentration oil. In this way, SP=PV, and i
=50. In this way, if the master pulses are reversely controlled by the multipliers 44 and 45 and both low sulfur concentration oil and high sulfur concentration oil are controlled simultaneously, the target value can be reached at a high speed, but the multiplier Only one of 44 and 45 may be provided and only one of them may be controlled. In any case, the property controller 39 operates instantaneously and does not perform integral control, so it has a small time constant, operates without delay, and there is no risk of hunting.

At startup, the output of the property controller 39 is controlled by the timer means for a certain period of time, 12 mA (i=
50), and when the fluid in the mixing flow path 16 reaches a steady state, the controller 39 adjusts to the new set value.
It is preferable that the output of

By instantaneously controlling the sulfur concentration, it is possible to control the sulfur concentration without delay or hunting, but if you also want to keep the integrated value of sulfur constant, for example, as shown in FIG. The measured value and the sulfur target value from terminal 41 are supplied to multipliers 61 and 62, respectively, and multiplied by the master pulse from terminal 63, resulting in a number of pulses proportional to these measured values and the target value. These pulses are detected by the integrated deviation detection circuit 64, which detects the difference between the integrated values of both pulses, and the analog value of the difference between the integrated values is supplied to the correction arithmetic circuit 65, and the terminal 41
A correction calculation is performed on the sulfur target value from , and the output thereof is supplied to the controller 39 as a set value.

As described above, according to the present invention, in a mixing device that performs normal ratio control, the properties of the mixed fluid are detected, this and the target value are added to the instantaneous value control controller, and the output is used to determine the ratio. Since the master pulse is increased/decreased for control, the response is fast and hunting does not occur. In the case of sampling control, when changing the mixing ratio, that is, changing the sulfur concentration or changing the flow rate, for each shipment or transfer, it is necessary to change the sampling cycle for each change, making handling difficult. It's troublesome. However, the present invention is not affected by such changes; for example, even if the flow rate is changed, the sulfur concentration remains the same. Furthermore, if configured as in the above embodiment, the output of the property controller at startup or switching is set to the value when the measured value matches the target value, or the changeover switches 27 to 31 are switched to terminal a. Works as a normal mixing device.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a fluid mixing device according to the present invention, Fig. 2 is a block diagram showing an example of its dead time compensation circuit, and Fig. 3 is a block diagram showing an example in which integrated deviation control is added to a property controller. It is a diagram. 11~15: Inlet flow path, 16: Mixing flow path, 17~
21: Flowmeter, 22-26: Ratio controller, 32-
36: Control valve, 37: Property detector, 39: Instantaneous value operation property controller, 42: Dead time compensation circuit, 4
3: Master pulse terminal, 44, 45: Multiplier.

Claims (1)

[Claims] 1. In a fluid mixing device that supplies fluids from a plurality of inlet channels to a mixing channel to mix the fluids, a ratio setting controller is provided in each of the inlet channels and controls the fluid flow rate. and a means for detecting the properties of the fluid in the mixing flow path; a property controller that operates at least instantaneously, into which the detected value is input, performs adjustment calculations with the set value, and outputs the property controller; first and second multipliers that multiply the output by the master pulse to output pulses whose pulse rates are controlled inversely to each other, and supply these to different ratio setting controllers as master pulses, respectively; A fluid mixing device comprising: