Principle and structure of micro control

1.Principle

Bentonite in clay has a strong adsorption capacity for methylene blue. The adsorption capacity depends on the type and origin of bentonite, but it also has a certain relationship with the degree of dispersion of bentonite. Therefore, the sample must be fully dispersed before measurement. In order to more accurately determine the large amount of blue absorption of zui.

Ultrasonic dispersion treatment of bentonite samples is based on ultrasonic waves to create a "cavitation" in the liquid, that is, the liquid will produce many tiny "holes" in the high frequency ultrasonic waves. When these "holes" grow to a certain size or are subjected to pressure waves, they will quickly burst. The instantaneous collapse of these holes can generate high temperature and high pressure, causing local shock waves in the liquid, which has a strong dispersion effect. Therefore, contaminants or aggregated agglomerates attached to the solid surface are quickly separated. By using this principle, the clay in the sample can be dispersed into fine particles or peeled off from the surface of the sand to fully disperse.

When the blue amount of the sample is measured by titration, mechanical stirring is required at the same time, and the sample is sufficiently contacted with methylene blue to carry out an adsorption reaction. The sample suspension was gradually titrated with a methylene blue solution and subjected to a spot test on a filter paper. When it was found that free methylene blue began to appear in the suspension, it was concluded that the sample had reached saturation adsorption (the titration reached the "end point"), thereby measuring the amount of blue absorption of the sample.

2. Instrument structure

The methylene blue clay analyzer is mainly composed of a sample dispersing device, a mechanical stirring and a titration device. The two units are independent and can work simultaneously, with the microcomputer controlling the dispersion processing and mixing time separately. Its structure is shown in the figure below:

(1) The sample dispersion device is composed of an ultrasonic cleaner (ultrasonic disperser), an accessory, and a timer. Ultrasonic cleaner (model MJ-50) is a small desktop full-transistor circuit ultrasonic device that uses a ceramic material of pressure point - aluminum zirconate titanate transducer with high conversion efficiency, good dispersion, low noise, and power. The consumption is also small. The ultrasonic cleaner can be used alone.

(2) Titration device

The automatic titrator has two automatic burettes, a burette 1 and a burette 2. The burette 1 is controlled by a "titration switch" and a high performance anticorrosive solenoid valve DZ1 to control the titration of the methylene blue solution; the burette 2 is pressed by hand to squeeze the glass beads to titrate the methylene blue solution. When two burettes are used simultaneously, the milliliter of the titrant must be read and added simultaneously. The solution bottle can be used with a 500ML small-mouth reagent bottle or a 1000ML small-mouth reagent bottle. After adding the methylene blue solution to the reagent bottle, the high-performance anti-corrosion solenoid valve DZ2 is controlled by the “liquid-filling switch”, and the gas source is pressurized by the DZ2 to make the methylene blue solution simultaneously. Burette 1 and burette 2, when the solution is filled with the burette. Release the “Dosing Switch” and return the solution to the solution bottle. The titrant is automatically zeroed.

(3) agitator

The working time of the AC motor is controlled by a microcomputer, and the coupling shaft is connected to the stirring shaft by the coupling to sufficiently stir the test liquid.

Instrument installation

1. Before installing the instrument, check whether the components are complete, whether there is any damage, and wipe the parts clean.

2. Place the instrument on a stable platform and connect the instrument's power cord to the AC220V/10A three-pin socket. Note that the power supply must be grounded to avoid operator shock.

3. Align the centerline of the chassis on the beaker carrier with the agitator shaft. Then tighten the set screw.

4. Place the solution bottle near the instrument. There are two straight tubes on the rubber stopper. One of them must be close to the bottom of the bottle and connected to the “inlet” with a hose. The other one receives the “air outlet” and must tighten the rubber stopper. Put the rubber double ball (or a compressed air source, pay attention to the air pressure should be less than 0.05Mpa) and connect it to the “air intake” with a leather tube.

5. Insert the ultrasonic power plug into the ultrasonic designated socket on the back of the instrument and set the ultrasonic original timer to the normally open state.

6. The ultrasonic cleaner can be used alone. When plugged into the socket specified by the instrument, be sure to set the timer on the ultrasonic cleaner to a continuous normally open state.