Sinter plant batching melt additive raw materials is the use of quicklime, due to the quicklime particle size less than 3mm, the use of belt scales pollution, therefore, in order to improve the batching accuracy and reduce the pollution of the production environment, the use of scales dense group of better, higher batching accuracy of the electronic spiral feeding scales, a better solution to the problems that exist in the quicklime batching and additive for the production of high-quality, high-yield, low-consumption of sintered ore has laid a solid foundation. The scale is a good solution to the problem of quicklime dosing.

2 scale installation and working principle

2.1 Scale installation

Spiral feeding scale consists of spiral weighing frame, weighing module, speed sensor and spiral feeder. The main part of the spiral weighing frame is composed of a screw feeder and a counterweight frame. Under the scale body, it is connected by a set of cross reeds, which constitutes the support point for the transmission of the scale's body force. The balance of the scale is adjusted by the counterweight block on the counterweight frame.

2.2 Measuring Principle of Electronic Spiral Scale

2.2.1 Working principle

Spiral scale body operation, in the unit time, the weight of the material in the spiral tube, the instantaneous weight of the material on the unit length of the spiral body, the spiral body running speed, only need to measure the instantaneous weight of the material on the unit length of the spiral body and the speed of the spiral body running can be derived from the total weight of the material in the unit time. Screw feeding scale is a combination of gravity weighing principle and screw conveying method to realize dynamic continuous measurement of electromechanical integration weighing device, compact structure, easy to use.

2.2.2 Screw scale speed sensor

Electromagnetic sensors are used to detect the instantaneous running speed of the spiral feeder, and such sensors are characterized by reliable detection, smooth operation and small maintenance. The sensor is installed in the head of the spiral shaft, composed of oscillator, trigger circuit and switching signal output device 3 parts.

The power supply of the sensor is DC24V, after the power supply is turned on, the oscillator starts to oscillate and produce a specific current, so that the oscillating coil installed on the ferrite generates an electromagnetic field, which is concentrated on the surface of the sensor sensing surface. If the test target is made of a magnetically conductive material, eddy currents are generated within the magnetic field as it approaches the sensing surface, consuming the oscillator's energy and causing the oscillation to decay. The amplitude of the oscillator thus decreases to a specific value, and the post-trigger circuit starts to work, outputting a pulse signal.

2.2.3 Measurement of instantaneous material quantity

Using the German-made HBMSQ500kg weighing module to measure the instantaneous value of the material, the load cell's rated load of 500kg, the sensitivity of 3mV/V (sensitivity for the measurement of a technical indicator of the module, when the load cell for the bridge voltage of 1V, plus the full load of its output is 3mV), the sensor per mV for 500kg/3mmV = 166.7kg/mV, then Spiral scale of the amount of timed material N (kg / h) = 166.7 (kg / mV) sensor output (mV) / time (h)

3 system hardware

This dosage system uses the ISP integrated weighing module. The weighing device includes: a special weighing module, a weighing display unit, a process control program, a weighing module, a speed sensor, a junction box and so on.

The measurement input channel of the weighing module is connected to one or more weighing modules, each of which provides a counting value related to the weight of the measurable material, and the module collects data 50 times per second. The module has two high speed discrete outputs, which trigger a continuous response time operation when the threshold voltage reaches a certain value, with a sealable digital connection, usually displaying the instantaneous weight on an external display unit, which can be inserted in the PLC chassis by means of a card slot. The weighing module has functions such as calibration 0-point preset, automatic tare, zero tracking and transient measurement, and also provides different data related to the weighing pan, including gross weight, net weight, measurement of the instantaneous flow related to stability, 0-point, overload, underload, manual, tare and other data, discrete outputs, tare value storage, preset value storage.

4 Application effect

Spiral feeding scale in the sintering production melt batching successfully applied to realize the automatic weight of the melt (quicklime) with the addition, thus greatly improving the batching accuracy, reduce the post environmental pollution, to improve the sintered minerals, quality and process energy consumption reduction has played a positive role, has a good application prospects and promotion value.