JPH04252939A - Method for measuring turbidity of treated fluid - Google Patents

Abstract

PURPOSE:To stably measure turbidity over a long period of time by preventing the contamination of measuring windows by allowing a definite amount of a clean fluid to flow to the outer peripheral part of a measuring pipe to measure the turbidity thereof from a pair of measuring windows provided in coaxial relation to a measuring opening. CONSTITUTION:A cylindrical body 7 is provided to the outer peripheral part of an erected measuring pipe 2 having a pair of measuring openings 6 and a pair of measuring windows 5 are provided to the cylindrical body 7 in coaxial relation to the openings 6 and a light source 3 and a detector 4 are respectively arranged to the windows 5. A pipeline 9 feeding waste water 1 by a pump 8 is provided to the bottom part of the measuring pipe 2 and a pipeline 10 suppying a clean fluid, for example, city water is provided to the bottom part of the cylindrical body 7. When waste water 1 and city water are supplied at the almost same rising speed and drained from a drain pipeline 11, the spaces between the waste water 1 and the windows 5 are cut off by city water and the windows 5 are not contaminated. In this state, the light of the light source 3 passes through the city water layer and the opening 6 of the measuring pipe 2 to attenuate corresponding to the turbidity in the waste water 1 and passes through the opposed opening 6 and the city water layer to be detected by the detector 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring turbidity of a process fluid.

0002

BACKGROUND OF THE INVENTION Manufacturing industries use large amounts of water. For example, in the steel industry, rolling mills use cooling water, and this cooling wastewater contains rolling oil and scale. In addition, iron and steel manufacturing facilities have dust collection equipment for environmental protection, and dust collection wastewater containing dust and sludge is discharged. Most of these wastewaters are recycled at water treatment facilities and reused as return water.

[0003] At this wastewater treatment plant, turbidity is measured for water quality control. A commonly used turbidity measuring method will be explained with reference to FIG. 2. The measuring tube 2 is immersed in the wastewater 1, so that the wastewater 1 flows into the measuring tube 2. On the other hand, the light emitted from the light source 3 is attenuated within the drainage water 1 and detected by the detector 4 on the opposite side.

When turbidity measurement is performed in this manner, dirt such as oil, dust, sludge, or organic matter adheres to the part of the pair of measurement windows 5 in which the light source 3 and detector 4 are provided that come into contact with the fluid. The turbidity measurement results vary greatly depending on the amount of deposits, and it must be cleaned frequently. For this reason, long-term measurements are virtually impossible, and measurements are limited to short-time measurements. Also, no appropriate measures have been found to prevent contamination.

[0005]

[Problems to be Solved by the Invention] When measuring the turbidity of a fluid, the present invention prevents fluid dirt from adhering to the light source and detector, and appropriately measures the turbidity of the processed fluid over a long period of time. The purpose is to provide a method.

[0006]

[Means for Solving the Problems] The present invention allows a processing fluid to flow through a measuring tube having a pair of measurement holes, and measures the amount of transmitted light by applying light from a direction perpendicular to the fluid flow, thereby determining the turbidity of the processing fluid. In this method, a certain amount of processing fluid is flowed into an upright measuring pipe having a pair of measuring openings, and a certain amount of clean fluid is flowed around the outer periphery of the measuring pipe. This is a method for measuring turbidity of a processing fluid, characterized in that measurement is carried out through a pair of measurement windows provided coaxially with the pair of measurement openings on the outer periphery.

[0007]

[Operation] In the transmitted light method of measuring the turbidity of a processing fluid, the present invention surrounds the processing fluid with clear fluid, so that the processing fluid does not come into direct contact with the measurement window.

[0008]

[Example] The method of measuring the turbidity of a processing fluid according to the present invention will be explained with reference to FIG. The measuring device A used in the turbidity measuring method of the present invention has a pair of measurement openings 6, and a cylindrical body 7 is installed on the outer periphery of the measuring tube 2, which is installed upright. A pair of measurement windows 5 are provided in this cylinder 7 coaxially with the pair of measurement openings 6, and a light source 3 and a detector 4 are installed in the windows 5, respectively. A pipe line 9 is provided at the bottom of the measuring tube 2 to supply waste water by a pump 8. A conduit 10 for supplying clean fluid, for example tap water, is provided at the bottom of the cylindrical body 7. At the upper end of the cylindrical body 7, a drainage pipe line 11 for a mixed fluid of drainage water and clean fluid is provided.

Therefore, when the waste water 1 and tap water, which are treatment fluids, are supplied from the bottom of the measuring device A at approximately the same rising speed and drained from the drain pipe 11, the distance between the waste water 1 and the pair of measurement windows 5 is The pair of measurement windows 5 will not be contaminated by the waste water 1 since they are in a state where they are blocked by tap water, which is a clean fluid. In this state, the light emitted from the light source 3 passes through the tap water layer and the pair of openings 6 in the measuring pipe 2, and then passes through the drain water layer 1.
The water is attenuated in accordance with its turbidity, and is detected by the detector 4 through the opening 6 on the opposite side and the tap water layer.

[0010] As for the supply conditions for the processing fluid and the clean fluid, in addition to the above-mentioned approximately same rising speed, if the rising speed of the clear fluid is slightly faster, the processing fluid will substantially come into contact with the measurement window 5. will disappear. Further, the clean fluid is not specified as long as it is free of impurities and does not react with the processing fluid.

In this embodiment, the measuring device A has an inner diameter of 30 mm.
, the measurement tube 2 is a cylinder with an outer diameter of 50 mm, and the opening 6 is 10 m.
m circle with an inner diameter of 80 mm at a position 15 mm from the outer circumference
A cylinder was placed. Measurement window 5 for light source 3 and detector 4
A transparent glass plate was used. This measuring device A was used to measure the turbidity of cooling water discharged from a rolling process in a steelworks. The measurement conditions were as follows: 1 liter of wastewater 1 per minute was introduced into the measuring tube 2 using a pump, and 2 liters of tap water was used as a clean fluid per minute. When measurement was carried out continuously for 10 days in this manner, there was no dirt on the measurement window 5 at all. As a comparative example, when the measurement was performed in the manner shown in FIG. 2, the turbidity measurement value gradually became higher after the start of the measurement, and began to show an abnormal value after one hour.

0012

[Effects of the Invention] According to the method for measuring turbidity of a treated fluid according to the present invention, the measurement window of the turbidity measuring device is free from dirt, so it is extremely advantageous that turbidity measurement can be carried out for a long period of time without any trouble, without the need for frequent cleaning. This is a great method.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a method for measuring turbidity of a processing fluid according to the present invention.

FIG. 2 is an explanatory diagram showing a conventional turbidity measurement method.

[Explanation of symbols]

1 Measured wastewater 2 Measurement tube 3 Light source 4 Detector 5 Measurement window 6 Measurement aperture 7 Cylindrical body 8 Pump 9 Supply pipe for wastewater to be measured 10 Clean fluid supply pipeline 11 Drainage pipe A Turbidity measuring device

Claims (1)

[Claims] Claim 1: A method of measuring the turbidity of a processing fluid by flowing a processing fluid into a measurement tube having a pair of measurement holes, applying light from a direction perpendicular to the fluid flow, and measuring the amount of transmitted light, the method comprising: At the same time, a certain amount of processing fluid is caused to flow through a measurement tube that is provided upright and has an opening for measurement, and a certain amount of clean fluid is caused to flow around the outer periphery of the measurement tube, and the pair of measurement openings are connected to the outer periphery of the clean fluid. A method for measuring turbidity of a processing fluid, characterized in that the turbidity is measured through a pair of measurement windows provided coaxially with the turbidity of a processing fluid.