JPS58139704A - Device for controlling detection of boundary of waste resin liquid - Google Patents

Abstract

PURPOSE:To detect the liquid boundary between org. resins and unnecessary waste liquid surely by measuring the conductivity of the waste liquid between a recovering tank for waste resin liquid and a three-way valve for recovering of org. resins, and controlling the three-way valve and a two-way valve for discharging the unnecessary waste liquid in accordance with the measured value. CONSTITUTION:Waste phenolic resin liquid is separated and settled in a tank 2 to unnecessary waste liquid 9 such as water and recovered resins 10. A three-way valve 3 for recovering resins is connected to the tank 2, and a two-way valve 4 for discharging the unnecessary waste liquid is connected to the three-way valve. A conductivity meter 5 is provided between the tank 2 and the three-way valve 3 and the conductivity of the waste resin liquid is measured. The measured value is put into a deciding device 6 in which the upper and lower limits of the conductivity are set. The value obtd. by adding a safety factor to the difference between the min. conductivity of the liquid 9 and the max. conductivity of the resin 10 is set in an operator 7 for change rate. The outputs of the device 6 and the operator 7 are inputted to a sequence controller 8 which controls the valve 3 and the valve 4. The boundary surface is detected surely by the above-mentioned control and the org. resins and the unnecessary waste liquid are separated and recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin waste liquid interface detection and control device that recovers phenol resin from #4Vi resin waste liquid and discharges unnecessary waste liquid.

Conventionally, a specific gravity change detection method has been used to separate and recover phenol liquid, which is an organic resin, and unnecessary waste liquid. Ta. There were also nine other methods using optical cecily. In this case, the color of the liquid was inconsistent and could not be used. Another method is the capacitance method, but the problem is that the conductivity of the liquid is too high, making it difficult to detect changes in capacitance.

The present invention has been provided in view of the above points, and is capable of reliably detecting an interface between an organic resin and an unnecessary waste liquid even when the interface detection cell is contaminated, the liquid temperature changes, and the liquid flow condition is detected. It is an object of the present invention to provide a resin waste liquid interface detection and control device that can separate and recover organic resin and unnecessary waste liquid.

Inside (2) is a tank in which the phenol resin △ liquid is allowed to settle from the phenol resin reaction vessel.In this tank (2), water (9) which is an unnecessary waste liquid and phenol (1O
) and are allowed to separate and settle. (3) is a three-way valve installed below the tank (2) for recovering phenol (l(2)). (4) is a nine-way valve connected to one side of the three-way valve (3). This allows unnecessary waste liquid to be discharged.

(5) is a conductivity meter placed between the tank (2) and the three-way valve (3), which measures the conductivity of the phenol resin waste liquid. (6) is a +lJ meter that determines the phenol (101) to be recovered after setting the upper and lower limits of the electrical conductivity of the phenolic resin. In other words, the lower limit of the electrical conductivity is set with an upper limit of 20μυ/1M and a lower limit of 111υ/1M, taking into account liquid temperature and zero-point variations. (7) is the minimum conductivity of unnecessary waste liquid and phenol (10
) is a change amount calculator that presets a value that takes into account a safety factor to the difference in the maximum conductivity of
The maximum conductivity of is 250, the safety factor is 1°3, and (250
Set 185μTJ/6R in -9,65)÷1.3. However, the safety factor H1 is set to 0 to 1.5. This set value is set using the grading slope setting digital switch 0. !
8) The open/close signal for the two-way valve (4) and the three-way valve (3) are determined based on the values from the tI′i determiner (6) and the change amount calculator (7).
The three-way valve (3) and the two-way valve (
4) to recover phenol (lO) and water (9).
It discharges.

Then, the phenol resin waste liquid is received from the phenol resin reaction vessel into the tank (2), and the waste liquid is allowed to stand still for a time required for sedimentation. And when settling is complete (standing time has elapsed),!
If the conductivity of the waste liquid is determined by the I'll meter (6) to be between the upper and lower limits, it is determined that the conductivity meter (6) is normal and sedimentation is complete, and the three-way valve (3) is turned to the collecting phenol tube side. Switch to If the judgment of the judgment device (6) is larger than the upper limit set value, it is judged that the sedimentation is not completed or that there is an abnormality (5), and an inspection instruction is notified to the operator. Also, if the judgment of the judgment device (6) is If it is smaller than the lower limit, it is determined that the conductivity meter (6) is dirty or malfunctioning, and an inspection instruction is sent to the operator. If the amount of change is greater than the set value, the three-way valve (3) is switched to the unnecessary waste liquid discharge side.At this time, the two-way valve (4) is in the closed state.In this state, the amount of change calculator (7
) is larger than the change amount setting value, and the judgment output of the judge (6
) is greater than the upper limit for several minutes, the two-way valve (4) is opened and the sterile waste liquid is discharged. The above several minutes are the separation time of water (9) and phenol (10),
One culm per minute for simple stirring and mixing! almost separated by li. If the outputs of the determiner (6) and the change amount calculator (7) change within a few minutes, it is determined that the conductivity meter (6) is abnormal and the operator is notified. Next, the output of the change amount calculator (7) is greater than the set value, and the output of the determiner (6) is greater than the upper limit value. (take a time lag to prevent residue)) If it is output, the end time is T for 1 g of phenol recovery. The outputs of the determination device (6) and the change amount calculation device (7) are input to the sequence controller (8) to control the three-way valve (3) and the two-way valve (4). In this way, the output value of the conductivity meter (5) is judged in real time according to the sequence of sedimentation separation operation of phenol+101, and the output value of the conductivity meter (5) is determined in real time.
5) It is what made the abnormality possible. Furthermore, by employing a conductivity meter (6) as the boundary surface detector, the influence of the flow state of the liquid is eliminated. As a method for detecting the boundary surface from the conductivity measurement signal, we not only calculate the magnitude of the conductivity value, but also calculate the change value, and by detecting the boundary surface, we can calculate the temperature of the precipitated phenol liquid and the phenol concentration detection cell. This prevents detection problems due to dirt.

The experimental results are shown below.

0 Recovered phenol electrical conductivity (liquid temperature: 26°C) 0 Liquid temperature - electrical conductivity (in the case of Linzuru A) Waste liquid generation as shown in L 0
However, the conductivity changes depending on the liquid temperature.

0 Electrical conductivity of unnecessary waste liquid (liquid temperature: 26°C) Of course, it is also possible to detect not only phenol but also organic substances such as methanol and formalin at the interface.

This engine #4 consists of the following: a three-way valve, a two-way valve, a conductivity meter, a judge, a change amount calculator, and a search system D-
Since the conductivity meter is configured as described above, and the detector is a conductivity meter, there is no difference between the fluid state and the static state, and the interface By performing detection, gradual changes due to discharge cell contamination can be ignored, interfaces can be reliably detected, organic resin components can be recovered, and unnecessary waste liquid can be discharged.

[Brief explanation of drawings]

The figure is a configuration diagram of an embodiment of the present invention. (2) Ketashiku, (3) is a three-way valve, (4) is a two-way valve, (
5) is a conductivity meter, (6) is a determiner, (7) is a variation calculator, and (8) is a sequence controller. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) A tank that separates and settles resin waste liquid containing organic resin into unnecessary waste liquid and recovered resin, a three-way valve that recovers the organic resin from this tank, and a two-way valve that is connected to one side of the three-way valve to discharge the unnecessary waste liquid. A conductivity meter is installed between the valve, the tank, and the three-way valve to measure the conductivity of the resin waste, and the upper and lower limits of the conductivity are set in advance based on the measured value signal from the conductivity, and the recovered resin is measured. ”, a change amount calculator that presets a value by adding a safety factor to the difference between the minimum conductivity of unnecessary waste liquid and the maximum conductivity of recovered resin, and a change amount calculator that determines the amount of change after starting to take out the recovered resin. In addition to controlling the three-way valve to the unnecessary waste liquid discharge side according to the value of the computing unit, the system also includes a sequence controller that controls the two-way valve to discharge unnecessary waste liquid according to the value of the determiner in this control state. Resin waste liquid interface detection control device.