US-12618814-B2 - Monitoring system and monitoring method

US12618814B2US 12618814 B2US12618814 B2US 12618814B2US-12618814-B2

Abstract

A system for monitoring the alkalinity of a treatment liquid in a treatment tank includes a reaction tank; an indicator burette which drops an indicator into the reaction tank; a reagent burette which drops an acidic reagent into the reaction tank; a probe-type absorptiometer to be inserted into the reaction tank; a measuring device which analyzes the transmittance of a solution detected by the absorptiometer to calculate the alkalinity; a first system that collects the treatment liquid from the treatment tank for storing and supplies the treatment liquid to the reaction tank; a control device which controls the operation of the first system so as to supply the treatment liquid to the reaction tank, outputs a completion signal to the measuring device, and controls a discharge system so as to discharge the treatment liquid in the reaction tank, when the calculation of alkalinity by the measuring device is completed.

Inventors

Masaru Chiyomaru
Hiroaki MIKAWA
Yuichi OKUZAKI

Assignees

MITSUBISHI HEAVY INDUSTRIES, LTD.

Dates

Publication Date: 20260505
Application Date: 20200804
Priority Date: 20191004

Claims (7)

1 . A monitoring system comprising: a reaction tank to which a solution is supplied; an indicator burette that drops an indicator into the reaction tank; a reagent burette that drops an acidic reagent into the reaction tank; an absorptiometry detector that is immersed in the solution; a measurement device that controls the indicator burette, the reagent burette, and the absorptiometry detector, and analyzes transmittance of the solution detected by the absorptiometry detector to measure an alkaline degree of the solution; a first system that collects a sample of alkaline treatment liquid from a treatment tank storing the treatment liquid and supplies the sample to the reaction tank as the solution; a discharge system that discharges the solution from the reaction tank to a waste liquid container; and a control device, wherein the first system includes: the treatment tank; a measuring pipe; a diluted solution container; the reaction tank; a first pipe connecting the treatment tank and the measuring pipe; a second pipe connecting the measuring pipe and the reaction tank; a third pipe connecting the measuring pipe and the waste liquid container; a fourth pipe connecting the measuring pipe and the waste liquid container; a first pump that is provided to the first pipe, and draws in the treatment liquid from the treatment tank and sends out the treatment liquid to the measuring pipe; a second pump that is provided to the third pipe, and draws in the treatment liquid sent out from the first pump to the measuring pipe; a third pump that is provided to the fourth pipe, and draws in a diluted solution stored in the diluted solution container and sent out the diluted solution to the measuring pipe; the control device operates the first pump, and further operates the second pump for a predetermined time to draw in a predetermined amount of the treatment liquid required for measurement to the measuring pipe, and thereafter, by operating the third pump to send out the diluted solution to the measuring pipe, provides the treatment liquid drawn in to the measuring pipe and the diluted solution to the reaction tank as the solution through the second pipe, and outputs a completion signal to the measurement device when supply of the solution to the reaction tank is completed, and controls the discharge system to discharge the solution from the reaction tank when measurement of the alkaline degree by the measurement device is completed, wherein the solution is monitored based on the alkaline degree of the solution which is measured.
2 . The monitoring system according to claim 1 , further comprising: a second system that supplies a standard alkaline solution having a known alkaline degree to the reaction tank, wherein the measurement device measures an alkaline degree of the standard alkaline solution, and the control device evaluates measurement accuracy by the measurement device based on the alkaline degree of the standard alkaline solution measured by the measurement device.
3 . The monitoring system according to claim 2 , wherein the control device operates the first system and stops the second system to monitor the alkaline degree of the treatment tank, and intermittently stops the first system and operates the second system while the first system is intermittently stopped to evaluate the measurement accuracy by the measurement device.
4 . The monitoring system according to claim 1 , further comprising: a third system that supplies pure water to the reaction tank, wherein the control device evaluates measurement accuracy by the measurement device based on an alkaline degree of the pure water measured by the measurement device.
5 . The monitoring system according to claim 2 , further comprising: a third system that supplies pure water to the reaction tank, wherein the control device evaluates measurement accuracy by the measurement device based on an alkaline degree of the pure water measured by the measurement device.
6 . The monitoring system according to claim 3 , further comprising: a third system that supplies pure water to the reaction tank, wherein the control device evaluates measurement accuracy by the measurement device based on an alkaline degree of the pure water measured by the measurement device.
7 . A monitoring method of a monitoring system including a reaction tank, an indicator burette, a reagent burette, a probe-type absorptiometry detector, a first system that collects alkaline treatment liquid from a treatment tank storing the treatment liquid and supplies the treatment liquid to the reaction tank, and a discharge system that discharges the treatment liquid from the reaction tank to a waste liquid container, wherein the first system includes: the treatment tank; a measuring pipe; a diluted solution container; the reaction tank; a first pipe connecting the treatment tank and the measuring pipe; a second pipe connecting the measuring pipe and the reaction tank; a third pipe connecting the measuring pipe and the waste liquid container; a fourth pipe connecting the measuring pipe and the waste liquid container; a first pump that is provided to the first pipe, and draws in the treatment liquid from the treatment tank and sends out the treatment liquid to the measuring pipe; a second pump that is provided to the third pipe, and draws in the treatment liquid sent out from the first pump to the measuring pipe; a third pump that is provided to the fourth pipe, and draws in a diluted solution stored in the diluted solution container and sent out the diluted solution to the measuring pipe, the monitoring method comprising: causing the monitoring system to; operate the first pump; operate the second pump for a predetermined time to draw in a predetermined amount of the treatment liquid required for measurement to the measuring pipe, operate the third pump to send out the diluted solution to the measuring pipe, provide the treatment liquid drawn in to the measuring pipe and the diluted solution to the reaction tank as the solution through the second pipe, operate the first system to supply the treatment liquid to the reaction tank, operate the indicator burette to drop an indicator into the reaction tank, operate the reagent burette to repeatedly drop an acidic reagent into the reaction tank, detect transmittance of the treatment liquid each time the reagent is dropped by the absorptiometry detector, measure an alkaline degree of the treatment liquid based on the transmittance, and control the discharge system to discharge the treatment liquid in the reaction tank when measurement of the alkaline degree is completed.

Description

RELATED APPLICATIONS The present application is a National Phase of International Application Number PCT/JP2020/029813 filed Aug. 4, 2020 and claims priority from Japanese Application Number 2019-183795 filed Oct. 4, 2019. TECHNICAL FIELD The present disclosure relates to a monitoring system and a monitoring method of an alkaline degree. The present application claims priority based on Japanese Patent Application No. 2019-183795 filed in Japan on Oct. 4, 2019, the contents of which are incorporated herein by reference. BACKGROUND ART In a line for performing a surface treatment of aircraft members such as aluminum or titanium, there are treatment steps such as degreasing, washing, etching, and coating. In each treatment step, it is necessary to manage concentration of a chemical in treatment liquid. For example, in an alkaline degreasing treatment step, an alkaline degree in the treatment liquid is measured by using a manual neutralization titration method, and a concentration management of the treatment liquid is performed. PTL 1 discloses a method for measuring the alkalinity of each substance in treatment liquid in a surface washing step of a semiconductor substrate. In the measuring method of PTL 1, a light emitting substance that chemically emits light in response to a specific substance in the treatment liquid is added to the treatment liquid to emit light, and the alkalinity of the specific substance is measured based on the light emitting lightness. CITATION LIST Patent Literature [PTL 1] Japanese Unexamined Patent Application Publication No. 7-306146 SUMMARY OF INVENTION Technical Problem As described above, the alkaline degree is often measured by using a manual analysis. In order to maintain the alkaline degree in the treatment liquid within a predetermined range, continuous and consecutive alkaline degree monitoring is required. However, manual alkaline degree measurement takes time, and even when the alkaline degree measurement is performed regularly, continuous monitoring is difficult. The alkaline degree in a degreasing treatment tank is affected by the number of treatments of a target product, treatment time, and other treatment steps on an upstream side. For example, when the number of treatments of the product increases rapidly, the alkaline degree of the treatment liquid also changes rapidly. However, the manual alkaline degree measurement may not be able to cope with such changes. The present disclosure provides a monitoring system and a monitoring method that can solve the above problems. Solution to Problem According to the present disclosure, there is provided a monitoring system including: a reaction tank to which a solution is supplied; an indicator burette that drops an indicator into the reaction tank; a reagent burette that drops an acidic reagent into the reaction tank; an absorptiometry detector that is immersed in the solution; a measurement device that controls the indicator burette, the reagent burette, and the absorptiometry detector, and analyzes transmittance of the solution detected by the absorptiometry detector to measure an alkaline degree of the solution; a first system that collects a sample of alkaline treatment liquid from a treatment tank storing the treatment liquid and supplies the sample to the reaction tank as the solution; a discharge system that discharges the solution from the reaction tank; and a control device, in which the control device controls an operation of the first system and outputs a completion signal to the measurement device when supply of the solution to the reaction tank is completed, and controls the discharge system to discharge the solution from the reaction tank when measurement of the alkaline degree by the measurement device is completed. According to the present disclosure, there is provided a monitoring method of a monitoring system including a reaction tank, an indicator burette, a reagent burette, a probe-type absorptiometry detector, a first system that collects alkaline treatment liquid from a treatment tank storing the treatment liquid and supplies the treatment liquid to the reaction tank, and a discharge system that discharges the treatment liquid from the reaction tank, the monitoring method including: causing the monitoring system to operate the first system to supply the treatment liquid to the reaction tank, operate the indicator burette to drop an indicator into the reaction tank, operate the reagent burette to repeatedly drop an acidic reagent into the reaction tank, detect transmittance of the treatment liquid each time the reagent is dropped by the absorptiometry detector, measure an alkaline degree of the treatment liquid based on the transmittance, and control the discharge system to discharge the treatment liquid in the reaction tank when measurement of the alkaline degree is completed. Advantageous Effects of Invention According to the above-mentioned monitoring system and the monitoring method, it is possible to