SU1413497A1 - Method of determining moisture and ash content of coal - Google Patents

Abstract

This invention relates to a heat power industry. The purpose of it is to reduce the time. The purpose of it is to reduce the time to determine the humidity and ash content of the fuel while maintaining the accuracy of the determination. The analyzed sample is heated at a constant speed in air in two stages, the first is from 20 to 150 ° C at a pressure of (20-50) 10 Pa, the second is more than 150 ° C at a pressure of 100- Pa with continuous recording of temperature and sample mass. The subsequent determination of moisture and ash content is carried out by calculation. 2 silt, 1 tab.

Description

WITH

4 X)

The invention relates to a power system and can be used in the analysis of coal in thermal power plants, industrial and heating boilers.

The aim of the invention is to reduce the detection time while maintaining accuracy.

FIG. 1 shows a diagram of a device that implements the proposed method; in fig. 2 - auxiliary schedule.

The essence of the invention is that in the proposed method, heating the angle from 20 to 150 ° C at a pressure of (20-50) X X O Pa leads to an intensification of moisture removal in the temperature range of 60-80 ° C due to a decrease in the boiling point of water. removal of moisture ends in early. than in the known method (at (Hchnpakova heating rate). With an equal increase in heating rate and in the known method, the process of removing moisture stops the noc; i.e. the beginning of the process of burning out the organic mass of coal (when the temperature reaches 200 ° C) what It causes a decrease in the accuracy of determination of humidity. In the proposed method, the process of removing moisture ends before the start of the process of burning out the organic mass (until the temperature reaches 150 ° C), which allows to accurately determine the moisture of the coal. When the sample is heated to complete burning (t; 700 ° C), the proposed the method makes it possible to more accurately determine the humidity with equal accuracy in determining the ash content at a higher heating rate, which in the final

this results in a shorter determination time while maintaining accuracy.

Conducted laboratory tests allow us to choose the proposed conditions for determining the humidity and ash content. At a temperature of more than 150 ° C, coal begins to burn out the organic mass (release of volatile substances), therefore, the moisture removal process must be completed before the temperature reaches 150 ° C. With a pressure of (50-100) -10 Pa, an insignificant decrease in the temperature of the most intensive removal of moisture is observed and the process of removal of moisture does not have time to finish before the process of burning out the organic mass of coal begins. With a pressure of (20-50) -10 Pa, the most intensive removal of moisture occurs in the temperature range of 60-80 ° C and the removal of moisture ends before the organic mass begins to burn out (which makes it possible to accurately determine the humidity). A further decrease in pressure does not lead to an increase in the accuracy of ; 1st

A device for carrying out the proposed method consists of vacuum thermal weights, including the heating chamber 1 of the heater 2, the scale 3, and the dish-shaped holding Tc. ib 4 with built-in thermocouple 5, system

we are 6 pumping out air, valve 7 and recorder 8.

Way

five

0

Q

5 and ash

implemented next time.

A sample of coal with a mass M is placed on the disc holder 4, the air exhaust system 6 is turned on (with the valve 7 closed) and the recorder 8. When the pressure in the heating chamber 1 is lowered, the heater 2 is turned on increasing the temperature according to a predetermined program. As the temperature rises, moisture is removed from coal, especially intensively in the temperature range of 60-80 ° C, after which the moisture removal rate decreases and when the temperature reaches 130-150 ° C, the moisture removal stops (dot t on the recorder 8 in Fig. 2 ). At this time, the valve 7 opens, the pressure in the heating chamber 1 rises to 100X XU Pa, and the temperature rises further in a flow-through air environment at a pressure of 100-10 Pa. The temperature is increased until the organic coal mass is burned out (point then on the tape of the recorder 8 in Fig. 2), then the heater 2, the air extraction system 6, the recorder 8 are turned off, and the valve 7 is closed.

Using temperature curves and sample mass loss (sample mass loss rate), the humidity is calculated by calculation.

and ash content

C7 .Wl

M

100%;

(one)

0

five

100%.

(2)

five

five

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,

M,

Example. The determination of the moisture and ash content of a laboratory sample of the Irbas-Borodino coal was carried out using the proposed method. Humidity and ash content of the sample, determined by the standard method, were respectively 28.9 and 7.1% (table, methods 11 and 12).

A sample weighing 49.51 mg was heated at a rate of 0.167 deg / s (10 deg / min) in the temperature range 20-150 ° C at a pressure of 20-10 Pa, and above 150 ° C - at a pressure of 100-10 Pa.

The mass of the remote moisture mi is 14.40 mg (Fig. 2), the total loss of mass, 06 mg, the full analysis time is 4200 s (70 min) with regard to the injection.

According to the formula (1) calculated the humidity of the sample

14 40

.%

By the formula (2) the ash content of the sample was calculated.

, l 49,51-46,06 A - -49-757 -100 “%

The deviation of the values obtained from the values determined by the standard method is within acceptable limits.

(12).

The results of the determination of moisture and ash content are tabulated.

Analysis of the data presented in the table shows that the minimum time for determining the moisture and ash content of coal according to the accuracy condition for the proposed method is reduced by 3 times.

The proposed method makes it possible to estimate the content of external and colloidal moisture within the humidity of the sample, since these types of moisture are removed in various

and also provides an increase in the labor productivity of the personnel of the chemical laboratories of the TPP.

Claims (1)

Invention Formula The method for determining the moisture and ash content of coal by heating the sample under analysis at a constant speed in an air environment until complete burnout, continuous recording of the temperature and mass of the sample during heating, followed by determining the moisture and ash content by calculation, characterized in that the temperature ranges ( outer 60- g of the dyeing time of determination with preserved- 80 ° C, colloidal 100-110 ° C). According to the accuracy of the determination, the heating of the sample is carried out in two stages: at the first - from 20 to 150 ° C at a pressure of (20-50) X X10 Pa, at the second - above 150 ° C at a pressure of 100-10 Pa. Using the proposed method allows you to adjust the mode of operation of boilers for the quality of the coal being burned. and also provides an increase in the labor productivity of the personnel of the chemical laboratories of the TPP. Invention Formula The method for determining the moisture and ash content of coal by heating the sample to be analyzed at a constant speed in air to complete burnout, continuously recording the temperature and mass of the sample during heating, followed by determining the moisture and ash content by calculation, characterized in that preserved  dyeing time determinations with preserved According to the accuracy of the determination, the heating of the sample is carried out in two stages: at the first - from 20 to 150 ° C at a pressure of (20-50) X X10 Pa, at the second - above 150 ° C at a pressure of 100-10 Pa. 12 800-25 -7.1 13200 7800 130 2400 40 13200 220 d H2 4/7 1 t: c beats go speed -800 temperature -600 -Sh -200 about shh / 772 WCfW