CN1055907C - Cement fully black raw meal heating control technique - Google Patents

Abstract

The present invention provides a cement black raw material heat allocation control technology which relates to a material sampling and analyzing method. The method of the present invention is mainly used for maintaining the stability of the raw material heat productivity in the cement black raw material preparation process. Through a designed blocky raw material sampling device and an oxygen bomb coal sample ash content measuring method, the raw material heat allocation fluctuation is controlled at 1.13%; compared with that of the existing conventional method, the raw material heat allocation fluctuation is improved by more than 4 times; the control lag time is obviously shortened. The method of the present invention has the great significance to clinker quality stabilization, vertical kiln yield improvement and energy saving.

Description

The cement fully black raw material are joined heat control method

The present invention relates to a kind of material sampling and analytical technology, belong to the manufacture of cement analysis technical field.

Black meal can make coal be evenly distributed in the raw material, and then makes coal ash can really become the mineral of grog.Thereby black meal shaft kiln calcination technology has many original advantages.Be widely used in shaft kiln cement plant at present.Because measurement of coal in black raw meal cooperates jointly to go into mill with raw material, thereby the operative employee on the kiln can't in time adjust coal according to the situation of burning till of kiln, and therefore, raw material are joined the stable of heat and suited most importantly, and it is the basis and the prerequisite of black meal calcining technology.

At present, the heat control method of joining of cement black meal is to adopt the coal in the finished product raw material is measured, according to the proportioning of the adjustment of the coal content in raw material coal, to keep the stable of coal content.This is actually the control to raw material coal content.Because the difference of ature of coal, identical coal content does not also mean that to have identical calorific value.With regard to the measuring method precision of present coal, general absolute error is 0.5%.Because error at measurment causes the degree of kiln temperature fluctuation and is calculated as follows:

Coal content is 10% in the setting raw material, and then the relative error of coal assay is in the raw material: $\frac{0.5\%}{10\%}\×100\%=5\%$

Therefore, the relative error that causes heat consumption of clinker also is 5%.

The setting heat consumption of clinker is 4180KJ/kg, the then calorific value of heat consumption of clinker fluctuation, and promptly absolute error is:

4180KJ/Kg×5％＝209KJ/Kg

Looking into relevant handbook knows: the specific heat of grog is 1.045KJ/kg. ℃, so the kiln temperature that causes of calorific value fluctuation is changed to thus: 209/1.045=200 ℃.Calculation result shows, under the situation of not considering the heat radiation of kiln body, because the error of coal measuring method can cause the kiln temperature to produce 200 ℃ fluctuation.

Thinking of the present invention not with the coal content in the raw material as controlling index, also not with the coal content results of raw material as the foundation of adjusting the coal proportioning, but directly measure the calorific value of bottom of the reservior coal, and determine to go in the raw material proportioning of coal-grinding, thereby in raw material, allocate the calorific value of setting exactly into according to the calorific value of bottom of the reservior coal.

The objective of the invention is to design a kind of analytical procedure and corresponding sampling unit, so that determine to go in the raw material proportioning of coal-grinding according to the calorific value of bottom of the reservior coal.

The calorific value of coal adopts the technical analysis method.According to present technical analysis precision level, the error at measurment of ash A, moisture content W and fugitive constituent V is respectively less than 0.5%, 0.5% and 1%, and the thermal value of establishing coal is 25000KJ/kg, and the degree of the kiln temperature fluctuation that above-mentioned error causes is calculated as follows:

Get by thermal value formula Q=K-384A-359W-100V differential

dQ＝-384dA-359dW-100dV

|dQ|＝(384dQ)+(359dW)+(100dV)

Relative error to heating-value determination is $\frac{\left|\mathrm{dQ}\right|}{Q}=\frac{1}{Q}\left(384\mathrm{dQ}\right)+\left(359\mathrm{dW}\right)+\left(100\mathrm{dV}\right)$

Q=25000KJ/kg; DA=0.5%; DW=0.5%; The dV=1% substitution gets $\frac{\left|\mathrm{dQ}\right|}{Q}=1.13\%$

The relative error that is heating-value determination is 1.13%, and correspondence causes that the relative error of the calorific value of heat consumption of clinker also is 1.13%.

The hear rate of still establishing grog is 4180KJ/kg, the then calorific value of heat consumption of clinker fluctuation, and promptly absolute error is: 4180 * 1.13%=47.23KJ/kg.The kiln temperature that causes of calorific value fluctuation is changed to thus

Calculation result shows that under the situation of not considering the heat radiation of kiln body, raw meal heating control technique of the present invention can make kiln temperature fluctuation range reduce 4.4 times.

In actual production process, for same coal piling moisture content fluctuation 0.5%, the cycle of fugitive constituent fluctuation 1% is very long, accordingly also can be longer to the cycle of moisture content and fugitive constituent control.In this cycle, moisture content and fugitive constituent can be considered constant to the influence of coal calorific value, thereby the thermal value formula of coal can be reduced to Q=K-384A, can record its calorific value by the ash of measuring coal.

Key problem in technology of the present invention is obtaining and its quick Check of Dust Element into the coal-grinding sample.

The present invention adopts special-purpose " lumpy material sampling unit " to obtain the sample into coal-grinding.Accompanying drawing is that " lumpy material sampling unit " of the present invention constitutes synoptic diagram, as shown in drawings, " lumpy material sampling unit " is made of first tripper 3, sub-material passage 4, crusher 5, second tripper 6, sub-material passage 7, disc type mill the 8, the 3rd tripper 9, sub-material path 10 and sample box 11.As shown in drawings, during sampling, at first enter first tripper 3 by 1 coal that gets off 2 at the bottom of the coal-hole, get an amount of coal in 4 minutes through the sub-material passage and send into crusher 5, after entering second tripper 6 by the coal sample after crusher 5 fragmentations, divide again through sub-material passage 7 and to get an amount of coal and enter disc type mill 8, grind 8 levigated coal samples by disc type and get an amount of sample by the 3rd tripper 9 and sub-material path 10 branch and enter sample box 11 and fall into main belt 13 under the coal-hole respectively, and send into raw mill 12 for measuring coal after getting with above-mentioned each tripper branch.

The present invention gets coal sample with the lumpy material sampling unit at the bottom of coal-hole, adopt oxygen bomb to record the ash of coal sample, and then the calorific value of calculating coal, described lumpy material sampling unit is made of first tripper (3), sub-material passage (4), crusher (5), second tripper (6), sub-material passage (7), disc type mill (8), the 3rd tripper (9), sub-material passage (10) and sample box (11), and the ash of described coal sample is the residue and the SO that burns and form after being burnt in oxygen by coal sample ₃Form.

The present invention adopts oxygen bomb to measure the ash of coal.With weight is that the coal sample of G is put into the nickel matter crucible of constant weight, and packs into together and fill in the oxygen bomb of 10ml water, and after the oxygen bomb oxygenation, coal sample is ignited in the electricity consumption sparking, treats (about 5-10 minute) behind the coal sample all burnt, and G1 is counted in the residue weighing after burning.Compare with the ash condition determination of standard, temperature raises rapidly during owing to the coal sample burning, makes the part sulphur in the coal be converted into gas SO, and then water-soluble generation HSO, with the HSO in the NaOH standard solution titration oxygen bomb, can obtain the volatile quantity G2 of SO in the ash, the ash of coal is calculated as follows: $A=\frac{G1+G2}{G}\×100\%$

Major advantage of the present invention has:

1. control accuracy is higher, is more than 4 times of present method therefor.

2. significantly shorten the lag time of control, be the control sense cycle maximum lag time. And the at present control of routine Be control sense cycle and material time of staying sum in raw mill lag time processed.

3. " lump material sampler " of the present invention can be applied directly to the sampler of the materials such as lime stone In, the raw material rate value qualification rate is significant for improving.

The present invention is applied to the preparation of cement fully black raw material, can effectively stablize raw material and join heat, and then stable shaft kiln is forged Burn and clinker quality, avoid unnecessary waste of fuel, energy savings. There is thousands of shaft kiln cement plants in China, The application of complete black meal calcining technology is comparatively general, utilizes the present invention will produce bigger economy and social benefit.

Claims (1)

1. cement fully black raw material are joined heat control method, it is characterized in that: at the bottom of coal-hole, get coal sample with the lumpy material sampling unit, adopt oxygen bomb to record the ash of coal sample, and then the calorific value of calculating coal, described lumpy material sampling unit is made of first tripper (3), sub-material passage (4), crusher (5), second tripper (6), sub-material passage (7), disc type mill (8), the 3rd tripper (9), sub-material passage (10) and sample box (11), and the ash of described coal sample is the residue and the SO that burns and form after being burnt in oxygen by coal sample ₃Form.

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