Paper industry used in coatings and other batches, intermittent operation of the preparation of chemical measurement. Using three shear beam sensor, dedicated connection module and a balanced circuit board with a dedicated junction box composed of field weighing station. Paper Making Chemical To ensure the stability of the weighing tank, the limit device will be installed. Like paint preparation often used multi-material a scale measurement, feeding weighing using "cumulative method." The components of the material according to the recipe requirements set in advance. In the instrument control began to feed the weighing, to the formula set value, the first feeding end, the instrument clear and back to zero, ready to feed the next kind of material weighing, all materials added, the instrument Returns the "total weight" status.
The whole process is under PLC or DCS control. The scale of the electronic scale for the paper industry is ± 2 kg, so it can only be used for the measurement of large components in the recipe. Paper Making Chemical The material of the small component will be measured by means of flowmeter and metering pump.
(1) the plane of the sensor must be kept horizontal, the roughness within the specified range; between the sensor elevation error within the specified range;
(2) the sensor can not bear the lateral force or super [Received date: 2011-08-04] set, installed to prohibit oblique hanging, twisted, the selected hanging point should be kept level; screw to withstand the sensor arm, should be vertical ; Should be installed limit device;
(3) the sensor can not be damp, due to moisture will make the sensor insulation worse, resulting in internal short circuit, performance degradation. In the open air, where the humidity is large, should be installed in the sensor moisture cover;
(4) to prevent the sensor electric breakdown, after the installation of the sensor with a soft connection wire will scale body and device active body shorted to avoid the scale body on the welding work.
The rotor flowmeter is a commonly used flow meter consisting of two components: a tapered tube extending from bottom to top and a rotor placed in a conical tube and movable freely up and down along the centerline of the tube. When the fluid flow is measured, the measured fluid flows from the lower end of the cone, and the flow of the fluid impinges on the rotor and produces a force on it. When the flow is large enough, Paper Making Chemical the force acts to hold the rotor and lift it up high. At the same time, the measured fluid flows through the annular cross section between the rotor and the tapered tube wall and flows from the upper end. When the measured fluid flow on the rotor force, Paper Making Chemical just equal to the weight of the rotor in the fluid (called the display weight), the rotor force is in balance and stay at a certain height. The position height of the rotor in the conical tube has a corresponding relationship with the flow rate passing therethrough. Therefore, the corresponding flow rate value can be obtained by observing the position height of the rotor in the conical tube.
Electromagnetic flowmeter can be used with the computer to achieve system control, with the hand valve, switch valve with the use, but each time to change the recipe also use the hand valve to adjust, and with the control valve can be used in the control room Adjustment. Flowmeter requires the measured fluid must have a certain conductivity, conductivity ≥ 5μS / cm, so some of the low conductivity of the fluid must be used to measure the mass flow meter, the price is relatively expensive.
In the installation and use of the flow meter should be noted that must be installed at the lowest point of the pipeline or the vertical section of the pipeline, Paper Making Chemical the fluid medium from bottom to top through the flow meter, Paper Making Chemical can not be installed in the highest position of the pipeline, this position easy to accumulate bubbles, and Must be full of circumstances. Paper Making Chemical The requirement for straight pipe is between the front 5D and the 3D (D is the diameter). In order to ensure the stability of the fluid in the measurement area and the accuracy of the measurement, it is possible to increase the length of the straight pipe section before and after, and then reduce the diameter to reduce the cross section of the measurement point. If necessary, use a flow stabilizer.