Application of the hottest weight loss scale in cl

  • Detail

Application of weight loss scale in clinker proportioning for a long time, DCM-1 electronic belt scale has been used for clinker proportioning in our plant. Due to the limitation of clinker inventory, the temperature of clinker entering the mill is high, which often causes the belt of the electronic scale to stretch, deviate or even burn out; It is difficult to calibrate the physical scale, with poor stability, high failure rate and low dynamic measurement accuracy, resulting in serious cement loss of more than 500t per month. In order to improve the accuracy of clinker batching measurement, our factory successively installed two sets in August, 1992 Φ 2.2m × M90s weight loss scale is installed on the 6.5m circulating flow cement mill, which has a good effect. The situation is introduced as follows

2 overview of m90s weight loss scale

m90s weight loss scale takes cpu8751 as the control core. It is mainly composed of five parts: electric vibrator, amplifier, sensor, measuring bin and master computer system, which is mainly used for continuous measurement of bulk solid materials

main technical indicators of scale body:

(1) control cycle: 30 ~ 255s

(2) measurement control accuracy: 0.5% ~ 1%

(3) unit hour output: 0.1 ~ 60t/h

(4) signal transmission distance: < 3000m

(5) applicable environment: amplifier temperature: - 10 ~ + 50 ℃

corresponding humidity: < 85%

thyristor temperature: - 15 ~ + 40 ℃

corresponding humidity: < 85%

an m90s weight loss scale can control 8 different material ratios at the same time, and its output is determined according to the given value

3 measurement control principle

m90s weight loss scale inputs the given data to the random memory through the keyboard, and the host will work according to the data requirements. Three series tension sensors are installed on the metering bin, and then the signal transmitted by the sensor is amplified into a DC voltage signal of 0.67 ~ 0.67v through a high-precision and low drift integrated operational amplifier as the input of a/d converter. The computer regularly samples 1 ~ 8 channels of a/d interface core one by one, and stops feeding when the given value is reached; After the delay is stable, the feeding starts. The amplifier's 6.67 ~ 0.67v DC voltage signal is calculated and controlled, and the a/d conversion is carried out one by one. When the computer compares this signal with the given value, the feeding stops. In this way, a working cycle is completed, and the feeding cumulative measurement of one cycle is displayed. In the process of loading and unloading within a certain period, the system will give an alarm and display the alarm station number, and the system will be in a waiting state. Start the next cycle of work until the feeding or blanking reaches the given value

4 installation and commissioning

4.1 tension sensors

(1) the three sensors on the metering bin must use the same range, and the tension sensors with different ranges should not be mixed

(2) the sensor must be installed in the middle of the steel wire rope (see Figure 1)

(3) after installation, the sensor shall not be subjected to lateral force due to any object contacting the sensor

Fig. 1 Schematic diagram of sensor installation

4.2 amplifier

(1) the amplifier must be debugged after the sensor and clamp clamping methods are shifted from the original mechanical clamping to pneumatic clamping, hydraulic clamping, etc. to expand the metering bin and after the hoisting of the blanking electric vibrator

(2) the power supply of the amplifier must be within 220V ± 10%, and it is not allowed to share the power supply with high-capacity electrical appliances with frequent startup and shutdown

(3) adjust the "zero adjustment" potentiometer so that the output voltage of the amplifier is about 0.6V

(4) adjust the amplifier magnification, put 4kg code on the blanking electric vibrator, and observe that the digital quantity of "analog quantity" displayed by the m90s host should be increased by 40 ~ 80. LEGO has been using ABS plastics to produce its iconic building blocks since the 1960s for roads with small flow, and smaller for roads with large flow. Generally, 20 numbers/kg ~ 10 numbers/kg are selected

4.3 electric vibrator and metering bin

(1) the distance between the discharge port of the charging electric vibrator and the metering bin shall be 20mm, and the charging and discharging electric vibrators can vibrate freely

(2) there must be sufficient safety distance between the discharge port of the blanking electric vibrator and the conveying equipment to ensure that the conveying equipment will not interfere with the blanking (see Figure 2)

(3) the high-power electric vibrator is selected as the feeding electric vibrator, so that the feeding time is shortened, the feeding time is prolonged, and the material flow is continuous

(4) the size of the measuring bin is determined according to the unit hour output of the mill. The mill of the plant is fed at 16t/h, the diameter of the cylinder of the clinker measuring bin is 800mm, and the slag meter is used; The largest electronic all-round testing machine in China has a test force of 600kN, and the diameter of the measuring silo cylinder is 800mm, and the diameter of the gypsum measuring silo is 600mm

Figure 2 Schematic diagram of m90s on-site installation

5 operation conditions

since August 1992, our factory has installed m90s weight-loss scales. The installation of two m90s weight-loss scales has reached the standard. After zero point correction and physical calibration, the measurement error is less than 1%, meeting the requirements of its technical indicators. It was put into normal operation in September of the same year. Due to the large vibration of the feeding electric vibrator, the armature is often broken, resulting in uneven feeding and affecting its accuracy. Slag moisture is large, and scaling and blocking often occur in the metering silo. Therefore, we take corresponding measures:

(1) for the armature fracture, 40mm × 40mm angle steel is welded around the armature for reinforcement

(2) strictly control the moisture entering the mill below 2%

after taking the above measures, the two weight-loss scales were calibrated in kind, and the measurement errors reached: No. 1: 0.528%; No. 2: 0.825%; The strength and wear resistance of 2 sets are added through appropriate heat treatment process (quenching and tempering, carburizing and quenching, etc.) Sometimes, special steel is embedded in the jaw, or steel sand is sprayed on the jaw surface The average error of the fixture weight-loss scale with a small experimental force is less than 1%. It is proved that the scale has good stability and basically meets the requirements of clinker proportioning measurement

6 effect evaluation

through installation, commissioning and operation, we believe that m90s weightlessness scale has the following functions:

(1) weightlessness scale is suitable for working in high temperature, high dust, strong vibration and other environments

(2) high degree of automation, and the discharge flow is automatically adjusted according to the given value

(3) it has the advantages of good stability and high dynamic measurement accuracy

(4) low failure rate and small amount of maintenance

(5) dynamic physical calibration is simple and can be carried out once a month or several months

7 precautions

(1) m90s weight loss scale is mainly used for measuring granular or block materials, and its particle size

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