JPS60133366A - Measurement of unburned portion in coal ash - Google Patents

Abstract

PURPOSE:To enable a quick and accurate measurement of unburned portion in coal ash with a portable device less susceptible to trouble by completely burning unburned portion in coal ash with a quick heating thereof in an infrared heating furnace to detect CO2 gas generated with an infrared gas analyzer. CONSTITUTION:Coal ash 27 from a quicklime producing furnace, a coal-firing boiler or the like is weighed into a porcelain boat 28 to be placed into a quartz tube 20 and a plug 21 with a carrier gas fed glass tube 23 is provided at one end 20a of the tube while a plug 22 with a delivery glass 24 leading to an infrared gas anaylzer 26 at the other end 20b thereof and then, the quartz tube is placed into an infrared heating furnace 29. The furnace 29 is controlled with a thermocouple 31 inserted into the tube 20 employing a temperature control unit 30 and CO2 gas generated is detected with the infrared gas analyzer 26 in terms of a specified wavelength of 2,350cm<-1>, 670cm<-1> or the like and the amount of unburned portion is calculated and recorded with a recording unit 32 from an integrated value of output signal. Thus, the measurement can be done with a small portable type device quickly at a high accuracy.

Description

[Detailed description of the invention] The present invention provides raw coal, fly ash,
This invention relates to a method for measuring the amount of unresolved substances such as clinker present in coal ash.

In coal-fired boilers, measurement of unburned content is particularly important in order to understand the combustion state. Therefore,
Currently, coal ash is heated and combusted using electricity and scales, and the weight loss after heating the coal ash to 815°C in accordance with 1 Japanese Industrial Standard J I 8M8815F Analysis Test Method for Coal Ash and Coke Ash is defined as weight loss percentage. I'm looking forward to it.

However, in such a method, (1) the electric furnace is heavy and it takes a lot of effort to transport it to the vicinity of the electric ft boiler equipment;

■ It takes time to measure the sample amount before and after the test.

■ It is necessary to periodically measure the tfR' of the coal ash during heating and check from the change in the amount of electricity whether the unburned content has been completely burned, and for this purpose operations such as cooling and weighing are required. it takes time.

■　It takes time for the electric furnace to heat up.

(2) It is necessary to select the combustion conditions after confirming the unburned content, or it takes a long time to complete the combustion test because the above points (1) to (3) take time. There are other problems. In order to solve these problems, a method was developed to measure unburned content using a portable thermobalance that can rapidly measure unburned content.

The configuration of this thermobalance will be explained below with reference to FIG. 1.

In the figure, l is a balance part of a dish electronic balance, and a support tube 3 having a sample holding part 2 at its upper end is placed. A sample 4 is placed in the sample holder 2, a protection tube 5 is placed over the sample holder 2 and the support tube 3, and an infrared heating furnace 2 containing a tungsten lamp 6 is arranged outside the protection tube 5. be done. A thermocouple 8 is inserted near the sample 4. The top electronic balance unit 1 is connected to a weighing circuit 9, and the page weighing circuit 9 is connected to a recording unit 10. The thermocouple 8 is connected to a recording unit lO and a program temperature control unit) JZ, which in turn is connected to a tungsten lamp 6.

This type of thermobalance uses an infrared heating furnace 2 as the heating system and an electronic balance as the weighing system, so it is possible to quickly measure unburned matter, and it also has the advantage of being freed from the need to weigh the sample amount. Rarely.

However, even when such an improved thermobalance is used, there are the following drawbacks.

(7) Although it is an electronic balance, it uses a balance system in its detection section, so care must be taken when packaging it during local transportation. In addition, insufficient packaging may result in damage to the equipment.

(b) The balance system has parts with weak mechanical strength, so care must be taken when handling it. For example, the support tube 3 placed on the balance is very thin and easily breaks. For this reason, the support tube 3
If it is made thicker, the accuracy of the balance will deteriorate.

The present invention has been made based on the above circumstances, and includes a step of rapidly heating coal ash in an infrared heating furnace to completely burn the unburned content present in the coal ash, and a process of discharging carbon dioxide gas generated by the combustion to a downstream side. Detected by an infrared gas analyzer installed in
The main feature is that the process of recording the detection signal of this infrared gas analyzer makes it possible to measure the amount of unburned content in coal ash easily and quickly, and also to be able to handle transportation such as a thermobalance. An object of the present invention is to provide a method for measuring unburned content in coal ash that does not require troublesome kt loading.

In the method of the present invention, coal ash is heated to completely burn off the unburned content in the coal ash, and the concentration of CO produced during this combustion is measured using an infrared gas meter.

However, infrared gas analyzers are usually used in a constant gas flow (a state in which gas at a certain temperature is continuously flowing), but in this case, 00□ temporarily occurs during the combustion gap. Therefore, it is necessary to evaluate the integrated value of the infrared absorption capacity by C0.

In this case, the relationship between the integral value of the amount of infrared absorption and the amount of unburned matter is determined in advance by the relational surface Jk, and using this relational fRk, the unburned matter i? You can also find j.

Therefore, there is no need to frequently conduct electric measurements of coal ash during heating and combustion of coal ash, and since the measurement ends at the same time as heating and combustion ends, it is possible to measure the amount of unburned matter easily and in a short time. can. In addition, when measuring, we only need to measure the concentration of CO generated by heating the coal ash.
There is no need for a device 2 that is difficult to handle, such as a thermobalance.

An embodiment of the present invention will be described below. The configuration of the measuring device used in the present invention will be explained with reference to FIG.

In the figure, 20 is a quartz tube, and both ends 20 of this quartz tube 20 are
Rubber stoppers 21.22 are attached to a and 20b, and glass tubes 23.24 are attached to these rubber stoppers 21.22.

One glass tube 24 is further connected to an infrared gas analyzer 26 via a rubber tube 25. A porcelain board 2B on which a sample 22 is placed is inserted into the quartz tube 20. An infrared heating furnace 29 is arranged around the quartz tube 2θ, and the infrared heating furnace 29 is connected to a temperature control unit 30. Further, a thermocouple 31 is inserted into the quartz tube 2O near the sample 22, and the thermocouple 3t is further connected to the warm control unit 5ovc.

An infrared gas analyzer 26 and a temperature control unit 30 are connected to a recording unit 32. Further, a rubber tube 33 is connected to the infrared gas analyzer 26.

Next, one embodiment of the method of the present invention using such an apparatus will be explained in terms of steps.

■ Take a certain amount of sample 2r on a scale and place it on the porcelain board 28.

■ After inserting the quartz tube 20 into the porcelain bow) 28, insert the rubber plugs 2j, 22 and the glass tube 23.2 at both ends.
Attach the 4th etc. and make the configuration as shown in Figure 2.

■ Carrier gas (usually Cot) is passed through the glass tube 23.
The temperature inside the infrared heating furnace 29 is raised and maintained at a predetermined temperature (usually 815° C. and 10° C.) while flowing the removed air).

(2) When the sample 22 is heated and the unburned matter therein is combusted, CO is generated, and the infrared rays disposed on the downstream side of CO are emitted through the Nu analyzer 26f. At this time, since CO8 selectively absorbs infrared rays of specific wavelengths (2350α-', 670 crn-', etc.), Go and l can be determined by measuring the amount of absorption of this infrared ray. Note that the infrared gas analyzer 26 is normally used to measure the gas concentration in a steady flow (here, C0, concentration), but here we aim to measure the total Co, fi generated due to combustion. Therefore, the integral value of the output signal of the infrared gas analyzer 26 is measured. In an actual infrared gas analyzer, this output signal is usually obtained as a DC voltage of 0 to 1V.

■ A calibration curve created in advance from the integral value of the above output signal (relationship curve m between the integral value of the output signal and the amount of unburned material)
Measure the unripe volume using k. This calibration curve is obtained by measuring the total amount of unburned matter on the same sample using the method specified in the Japanese Industrial Standards and the method of the present invention described above, and determining the relationship between these measurement results. If this calibration curve is prepared in advance, there is no need to create it for each measurement.

The following is an example of an experiment conducted to confirm the accuracy of the method of the present invention.

■ Coal A, coal in a coal combustion test furnace.

C charcoal, D charcoal, coal, and coal are burned under various conditions to produce coal ash (fly ash) each having a different amount of unburned content.

■ Take 500 ql of the obtained coal ash and load it into the measuring device described above.

■ Rapidly raise the temperature of the infrared heating furnace to a predetermined temperature (usually 815°C) while flowing carrier gas.

(2) The Co11 infrared gas analyzer 2e24 generated with the combustion of unburned matter - the output signal (change in DC voltage) of the infrared gas analyzer 26 at that time is recorded in the recording unit 32.

■ The entire measurement chart obtained is shown in Figure 3. Here, since the peak of the output signal due to pressure is due to the combustion of unburned matter in the coal ash, the peak area 8 is proportional to the amount of unburned matter. Therefore, this peak mochi-like B (area of the portion shown in diagonal letters) is calculated for each sample.

■ Contain the same sample as above and add it to the unburned content t' using a different method (in this case, the JIS method). Figure 4 shows a diagram γv in which the amount of unburned matter measured by this alternative method corresponds to the aforementioned peak area and t. As a result, there is a good linear relationship between the bevel surface I and the amount of unburned matter.

As mentioned above, the present invention rapidly heats coal ash in an infrared heating furnace to completely burn the unburned content present in the coal ash,
The CO generated during this combustion is recorded as the output of an infrared gas analyzer. Then, from the integral value of this output signal, calculate the amount of unburned content in the coal ash? It is calculated.

Therefore, when heating coal ash, since an infrared heating furnace is used, it is possible to raise and lower the temperature of the heating furnace in a short time, which in turn leads to a reduction in measurement time. In addition, there is no need to frequently perform direct measurements of coal ash during heating and combustion.
Furthermore, since the measurement ends at the same time as the heating combustion ends, the amount of unburned matter h+ll can be determined easily and in a short time. Furthermore, during the measurement, CO generated.

Since it only measures the output signal of an infrared gas analyzer (actually equivalent to this), it has great effects, such as eliminating the need for equipment that is difficult to handle, such as a thermobalance.

According to the present invention, the amount of unburned content in coal ash can be measured easily and in a short time, and the amount of unburned content in coal ash can be measured easily and in a short time. We can provide a minute measurement method.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional thermobalance, Figures 2 and 2 are block diagrams of a measuring device according to an embodiment of the present invention, and Fig. 3 is a characteristic diagram showing changes in the output signal of the above device with respect to heating time. Figure 4 is a characteristic diagram showing the relationship between the amount of unburned content in coal ash and the peak area. 2O...Quartz tube, 26...Infrared gas analyzer, 22
... Sample, 28 ... Porcelain boat, 29 ... Infrared heating furnace, 30 ... Temperature control unit, 31 ... Thermocouple, 32 ... Recording unit. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] There is a process in which coal ash is rapidly heated in an infrared heating furnace to completely burn out the unresolved components present in the coal ash, and carbon dioxide produced by the combustion is detected by an infrared gas analyzer installed downstream. 1. A method for measuring unresolved matter in coal ash, comprising the step of recording a detection signal of a gas analyzer.