JPS6020057B2 - Fluid mixing and shipping device - Google Patents

Description

[Detailed Description of the Invention] This invention mixes a plurality of fluids with their flow rates controlled in a ratio manner, and supplies the mixed fluids to a plurality of shipping ports having flow rate adjustment means while controlling their ratios. The present invention relates to a fluid mixing and shipping device having means for setting a total flow rate.

In a conventional fluid mixing and shipping device of this kind, as shown in FIG. 1, fluids are flowed into mixed fluid paths 11 and 12, respectively, and the flow rates of these fluids are controlled in proportion. That is, flow meters 13 and 1 are installed for the fluid volumes 11 and 12, respectively.
4 is provided, and the flow rates detected by the flowmeters 13 and 14 are input to flow rate ratio controllers 15 and 16. flow ratio controller 15,
The opening degrees of control valves 17 and 18 inserted into the fluid passages 11 and 12, respectively, are controlled according to the detected flow rate and the set ratio so that the ratio is set in advance at 16.

The controlled fluid outputs, ie, the fluids from the control valves 17 and 18, are mixed in the mixing fluid path 19. Conventionally, in order to set and control the total amount of the mixed fluid, the mixed fluid path 19
The pressure of the mixed fluid inside is detected by a pressure gauge 21, and its output pressure is supplied to a pressure regulator 22, where it is calculated with the set pressure. The output signal is converted into a frequency signal by the current frequency converter 23, and this frequency signal is given to the flow rate ratio controllers 15 and 16 as a ratio setting signal.
In this way, the total flow rate in the mixed fluid path 19 is controlled,
The fluid pressure is brought to a set point.

The fluid path 19 branches into branch paths 24, 25, and 26 and reaches shipping ports 27, 28, and 29. These shipping ports 27, 28
, 29 are each provided with means for controlling the shipping flow rate.

In other words, the flowmeters 31, 32, 33 are connected to the branch path 24,
25 and 26, and these detected flow rates are detected by controllers 34 and 26.
35 and 36 (denoted as shipping port controllers), respectively. A signal corresponding to the difference between the flow rate set and the measured flow rate is detected in these controllers, and the control valves 37 and 3 inserted into the branch paths 24, 25, and 26, respectively, are detected based on the output.
The opening degrees of valves 8 and 39 (referred to as control valves at the shipping port) are controlled, respectively. According to such a fluid mixing and shipping device,
As the number of shipping ports 27, 28, and 29 increases or decreases, it is necessary to change the setting value for the pressure regulator 22, that is, the total shipping amount.

Furthermore, even if the number of shipments is the same, when supplying mixed petroleum to lead or tank trucks, the flow rate of the mixed fluid to be supplied differs depending on the size of the tanker or tank truck.
Therefore, it was necessary to similarly change the set value of the flow rate of the mixed fluid using the pressure regulator 22. However, it has been difficult to accurately control the flow rate using pressure in this way. For example, if a long or thin branch pipe is provided from the shipping port to the mixed fluid path 19,
Since the pressure loss is large, the desired flow rate may not be obtained at the shipping port even if the control valve is fully open.

In other words, the state of the flow rate at the shipping port does not appear as the pressure in the mixed fluid path 19 due to pressure loss in the branch path and the like. Furthermore, there is also a drawback that a hunting phenomenon tends to occur if the pressure setting value is too large. An object of the present invention is to provide a fluid mixing and shipping device that is flexible when the number of shipping ports or shipping flow rate changes and can provide a desired flow rate to each shipping port.

According to this invention, the set flow rate value of the controller for the branch path of each shipping port is input to the determination circuit, and the valve opening set value is output based on the total flow rate value of the set flow rate values.

In addition, the maximum or minimum opening of the control valve in the branch path of each shipping port is detected as a valve opening measurement signal, and the valve opening measurement signal and the valve opening set value are input to the valve opening controller. ,
In order to control the flow rate of the mixed fluid in the mixing fluid path, a set value is set for each flow rate ratio controller in the mixed fluid path so that the valve relationship measurement signal approaches the valve relationship setting value. Supplied from the relationship controller. At this time, the valve opening setting value is selected so that the control valve of each branch path has an appropriate degree of control that is easy to control. In other words, if the control valve at the shipping port is fully open, the outflow volume of the mixed fluid pipe, that is, the total flow rate, is insufficient, so increase the total flow rate to the maximum opening of the control valve at the shipping port. The setting value for the controller for controlling the total flow rate may be changed so that the opening is at an appropriate opening, that is, an opening that is a certain distance from full open.

Conversely, if the total flow rate is too large, the opening degree of the control valve at the shipping port will be the minimum, so this will be detected, the total flow rate will be reduced, and the valve with the minimum opening degree will be adjusted to the appropriate opening degree. The setting value for the total flow rate may be changed so that the opening degree is a certain distance from the fully closed position. For example, FIG. 2 shows an embodiment of a mixed shipping device according to the present invention, with the same reference numerals attached to parts corresponding to those in FIG. 1.

In this embodiment, the valve opening detection circuit 41 detects the opening degree that is the most open among the control valves 37, 38, 39 for each shipping port 27, 28, 29. Further, the control state of the controllers 34, 35, and 36 for controlling the flow rate to the shipping port, that is, the set flow rate value is determined by the judgment circuit 42.
supplied to The determination circuit 42 outputs an appropriate valve opening setting value based on the total flow rate of the input set flow rate values.

For example, the flow rates Q, , Q2 for the shipping ports 27, 28, 29
, A if the setting value of Q3 is 0%, B if it is 20%, 80
%, the setting signals for the controllers 34, 35, and 36 are generally controlled sequentially by program control, and one of the above-mentioned setting signals A, B, and C is given in a predetermined order. For example, as shown in Figure 3, the controller 3
Each setting signal SP, , SP2, S for 4, 35, 36
P3 is changed. As shown as SPo in Figure 3, if the set values SP, , SP2, and SP3 of each shipping port are all A, then SPo is 0 and A', and if any of them is B and the state C is If it does not exist, it is set as B', and if any C is included, it is set as C'.

A' is assumed to be 0%, B' is assumed to be 20%, and C' is assumed to be 80%. It is obtained from the circuit 42 which determines which of A', B', and O. Depending on the state of the contact signal indicating the setting signals SP, , SP2, SP3 given from each controller 34, 35, 36, one of A', B', and O is selected. For example, the fourth
As shown in the figure, a circuit 43 that generates a voltage or current of 0% or less, a circuit 44 that generates a voltage or current corresponding to 0 to 50%, and a circuit that generates a voltage or current between 0 and 100%. 45 are provided.

Each of these circuits is selected to have an appropriate value as required, and a switch 46 is connected to the output side of any one of these circuits 43 to 45. The switch 46 is connected to circuits 43, 44, and 45 depending on the state of the contact signal from each controller, ie, A', B', or O, and generates a setting output SPo. In order to output these setting signals A', B', and C', they may be switched depending on the number of C's and the number of B's in the setting signals SP, to SP3. For example, as shown in FIG. 5, a voltage dividing resistor 49 having many taps is connected between the power supply terminal 47 and the ground, and a switch 46 is selectively connected to one of the taps. If the output voltage is the smallest, signal A is output, then signal B is output, and then according to the number of C, C, , C2, C3, C4, and the higher the number of C, the higher the voltage is output. good. Depending on the case, the output may be adjusted depending on the number of B's. Furthermore, as shown in FIG. 6, the setting values SP, ~SP3 of each shipping port are added by an adder circuit 49, and the addition result is supplied to an arithmetic circuit 51, and when there is no shipment, it is set to 0%, but the Inside, the control valves 37 and 3 at the shipping port are restricted with upper and lower limits.
It is also possible to obtain the set value SPo by limiting the values 8 and 39 to a range in which flow rate control can be easily performed.

This can also be done by similarly limiting the upper and lower limits in the case of determining in FIGS. 4 and 5. Further, an appropriate gradient may be applied depending on the upper and lower limits. That is, for example, as shown in FIG. 7, for the sum 2SP of the set values of each control valve, the output SPo of the arithmetic circuit 51 outputs a certain value even if 2SP is zero, and when ZSP is close to 100%, it is SP. is a constant value of 100% or less. In this way, the controllability is poor at the fully closed position or near the fully opened position of the control valve, but it is possible to avoid using such a position. As shown in FIG. 2, the valve opening set value SPo from the determination circuit 42 and the output PV of the valve opening detection circuit 41 are supplied to a valve relationship controller 52. In this example, as described above, the valve opening degree detection circuit 41 detects the maximum opening degree of the control valves 37, 38, and 39. The set value SPo at this time is the maximum correlation of the control valves 37, 38, and 39 at the shipping port.
The setting value of the controller for that valve is selected so that it becomes the optimum opening, and this valve opening setting value SPo
A deviation signal between and the SV is obtained by the controller 52, and a signal corresponding to this deviation signal is given to the current frequency converter 23,
From there, the ratio setting signals given to the flow rate ratio controllers 15 and 16 are changed. In other words, as described above, in the determination circuit 42, the opening degree of the valve is set to be smaller than, for example, full open, and in addition, in the valve relation detection circuit 41, the maximum opening degree, for example, fully open, is detected, and this full open is taken as a measurement value, and this is used for judgment. The controller 52 controls the circuit 42 so that it approaches the set value (in this example, a value smaller than fully open), and in this example, the total flow rate of the mixed fluid paths 11 and 12 is increased, and the control valve 37 ,38,
The fully opened valve in 39 is determined by the set value of the determination circuit 42 (
(relationship distance far from full throttle). When the set value SPo for the valve opening controller 52 is suddenly changed, the valve temporarily operates in the opposite direction to the intended purpose, and then returns to normal operation. Therefore, the rate of change of this set value SPo needs to be smaller than the response speeds of the shipping and supplying sides. Hunting is likely to occur if the control valve at the shipping port is tightened too much before shipping.

For this purpose, for example, as shown in FIG. 8, the set value SP for the total flow rate. If it is less than 15%, there is such a possibility, and when the control valves 37, 38, 39 are half open,
That is, in the state B in FIG. 3, the switches 53, 54, 55
is turned on. When all the switches 53, 54, and 55 are off, these switches 53 to 55 are input to the low level selection circuit 56, and when all these switches are off, for example, 15% + Q is output and the valve is opened. degree controller 57
is supplied to This controller 57 is supplied with a setting signal SPo, and if even one of the switches 53 to 55 is on, the output of the controller 57 becomes positive. Therefore, the controller 52 side is selected by the controller selection circuit 58 and is supplied to the current frequency converter 23. However, if all the switches 53 to 55 are off, the output of the controller 57 will be negative, that is, if each control valve is too tight, the output of the controller 57 will be at a low level, and this output will be sent to the controller selection circuit 58.
selected.

Therefore, control is performed to prevent over-tightening. As described above, the fluid mixing and shipping device according to the present invention allows the control valve at the shipping port to have the most effective control, that is, the most controllable control valve, based on the control valve with the highest degree of control. A set value for the total flow rate is controlled.

Alternatively, the setting value for the total flow rate is controlled so that the least relevant control valve is taken out and it has the best opening degree. In this way, since control is based on the control valve at the shipping port, the control range of the control valve can be expanded, and it can be applied flexibly to changes in the number of shipping ports and changes in the flow rate at the shipping port. .

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a conventional fluid mixing and shipping device, Fig. 2 is a system diagram showing an example of a fluid mixing and shipping device according to the present invention, and Fig. 3 is a diagram showing an example of how to create set values in the judgment circuit. , FIG. 4 and FIG. 5 each show an example of the determination circuit, FIG. 6 is a system diagram showing another example of the fluid mixing and shipping device according to the present invention, and FIG. A curve diagram showing an example of input/output characteristics, and FIG. 8 is a block diagram showing a main part of still another example of the fluid mixing and shipping device according to the present invention. 11, 12: Fluid path for fluid to be mixed, 13, 14
, 31, 32, 33: flow meter, 15, 16: flow ratio controller, 17, 18, 37, 38, 39: control valve, 19:
Mixed fluid path, 23: Current frequency converter, 27, 28, 2
9: Shipping port, 24, 25, 26: Branch road, 34, 35,
36: Controller, 41: Valve opening detection circuit, 42: Judgment circuit, 52: Valve function controller. Figure 1, figure 2, figure 3, figure 5, figure 5, figure C, figure 7, figure 8.

Claims (1)

[Claims] 1 A flow meter is provided in each of the plurality of mixed fluid paths,
The detected flow rate from each flow meter is supplied to a flow rate ratio controller, and these flow rate ratio controllers are inserted into the corresponding mixed fluid path according to the output of the controller so that the set flow rate is achieved. The valve opening degrees of the control valves are controlled respectively, and the fluids to be mixed flowing out from these control valves are mixed in a mixing fluid path, and the mixed fluid path is branched and supplied to a plurality of shipping ports through branch paths, and these branches Each path is equipped with a flow meter that detects the flow rate, and these detected flow rates are given to controllers whose flow rates are set individually, and the outputs of these controllers are used to control the corresponding branches so that the set flow rates are achieved. In a fluid mixing and shipping device in which the opening of the control valve in the passage is controlled, the set flow rate given to each controller of each branch passage is input, and the appropriate valve opening set value is output based on the total flow value. a valve opening detection circuit that receives a signal indicating the opening of the control valve of each branch path and outputs a signal indicating the maximum opening or minimum opening as a valve opening measurement signal; The valve opening setting value from the determination circuit and the valve opening measurement signal from the valve opening detection circuit are input, and the mixed fluid path is controlled so that the valve opening measurement signal approaches the valve opening setting value. 1. A fluid mixing and shipping device comprising: a valve opening controller that supplies a set value to each flow rate ratio controller in a fluid path to be mixed in order to control the flow rate of the mixed fluid.