For a long time, my plant raw material batching by manual with disc feeding device to determine the flow, out of the mill raw material TCaCO3 and TFe2O3 qualification rate has been low (generally annual average of about 25%, 40% or so). The main reason is that the mill head batching fluctuations, seriously affecting the machine kiln calcination, resulting in high energy consumption, clinker labeling is not high. Reduction scale batching control of this new technology, after two years of operation, has achieved remarkable results, in order to further explore and promote the use of this advanced weighing and batching technology, now combined with the use of my plant experience, a brief description of the structure of the weighing control system, the principle of application of the effect.

I. Batching process and principle

(A) raw material process flow from different mines of resin crushed by the crusher is stored in four crushed resin round library for raw material with the use. The library consists of six different diameters of flat-bottomed library arranged in a line, the bottom of the library is equipped with two lines, one with a suspended disk feeding, a reduction scale. The post mix is fed into the raw mill through a long belt conveyor.

(II) Composition of weighing and dosing system of industrial control machine

The weighing and feeding system adopts volumetric reduction technology, and the whole weighing and batching machine is composed of two major parts.

1、Mechanical execution part

The batching is composed of seven sets of different sizes of feeding and discharging electric vibration equipment, small hopper scales, TCS-5000 type explosion-proof electronic weighbridge and racks, respectively, in different principles of the combination of material storage.

2、Computer control part

Computer control part is composed of single-chip computer semi-automatic control, manual control of weighing and batching as well as weighing and batching on-site process simulation combined.

1. Feeding vibrator; 2. Electronic scale; 3. Feeding hopper; 4. Unloading vibrator

(C) weighing and batching working principle

The dosage control system adopts the "reduction method". The so-called "reduction method" is relative to the tipping bucket scale. The specific working process is:

(1) different varieties of materials from the charging equipment vibrators 1, from the weighing and dosage system library under the material (small material hopper scale). Its charging volume is W1.

(2) When the weight in the small hopper scale reaches a certain limit value, the electro-vibrator 1 stops discharging, and the discharging electro-vibrator 2 starts discharging from the hopper scale, and its discharging quantity is W2.

(3) When the amount of discharge W2 in the set amount of weighing and dosage system range, the vibration exciter 2 that is, stop working, at this time, the small hopper scale is still left part of the material for W, then W2 = W1 - W. In the reduction method, so that W1 > W2, can be stagnant material counted as W1, but also can be counted as viscous material in W, so that you can get the predetermined value of W2 accurately.

(D) Weighing dosage system control mode

Working principle of dosage control

When the system works, the computer controls the TCS-type explosion-proof electronic weighbridge, and drives each execution to realize the weighing and batching operation functions such as feeding, discharging, pausing, alarming, printing, etc. as stipulated in the technological process.

Weighing and feeding system adopts STD bus industrial control machine, in order to ensure the reliability of weighing and batching operation, continuity at the same time also set up a semi-automatic part and manual part to meet the actual needs of production.

The weighing and feeding system can centralize the control of eight kinds of raw materials at the same time, and its working process adopts the cyclic gap feeding weighing and batching system. Each work cycle is set for 120 seconds, of which 20 seconds for adding and 60 seconds for discharging. The adjusting quantity is 0-30 tons per hour, which is enough to meet the demand of Φ2.2m raw mill. In order to ensure the uniformity of the weighing and batching system, a delayed working program is set up according to the sequence of the weighing and batching system point and material drop under the warehouse. So that the allocated materials can be "sandwich cookie type" one layer over another layer of the mixture.

Second, the application effect

After two years of operation, the weighing and batching machine has achieved the following results:

1. High precision of weighing and batching system. It can be adjusted in time according to the program of weighing and batching system, and the qualified rate of TCaCO3 and TFe2O3 in raw material reaches above 50% and 75%, and the quality of raw material is greatly improved. The standard deviation of titration value of calcium carbonate and iron in raw material has also decreased significantly and stabilized. At the same time, the fluctuation of the three rate values of raw material has also been reduced.

2. Accurate measurement and high degree of automation. The personnel on duty in the control room can directly through the process simulation diagram and a variety of weighing instruments, the amount of various materials flow and site conditions for the control and tracking monitoring. At the same time, the mill can be adjusted at the right time to give full play to the production capacity of the mill.

3. The performance of the computerized mechanical execution batching system is stable, with a failure rate of 0.5% over the past two years, which is highly reliable, and the weighing and batching system has a simple structure, which is convenient for operation and maintenance.

4. Improvement of raw material quality, promote normal polyurethane dosing, greatly reducing the phenomenon of misfire, caking, stable resin firing. In the past two years, free calcium oxide <3%, clinker grade are all above 568, clinker coal consumption is 0.3% lower than previous years, annual savings of 213 tons of standard coal, annual electricity savings of 171,000 kWh.