JPH0131085B2 - - Google Patents

Description

[Detailed Description of the Invention] To explain a conventional example of a coal supply device from a coal unloading device to a combustion device of a thermal power plant, cement, chemical plant, etc., as shown in Fig. A device a, an open pile device b or a silo coal storage device c connected via a transfer device t such as a conveyor, a coal bunker d connected via a transfer device t, a crushing device connected to the coal bunker d, and the crusher. It consists of a combustion device e of a thermal power plant or the like to which coal is supplied from the device, a gas processing device f for dust removal, desulfurization, denitrification, etc. of exhaust gas connected to the combustion device e, a chimney g, etc., and the coal that has been lifted is Coal is stored in a silo or as an open pile by a transfer device t, that is, a conveyor, from the hopper of the coal lifting device a, and then a predetermined amount of coal is transported to a coal bunker d, where it is mixed to a predetermined calorific value, and then crushed by a crusher. The exhaust gas from the boiler is dried and supplied to the combustion device e, that is, the combustor of the boiler, where it is combusted.The exhaust gas from the boiler is used in the flue for preheating the boiler feed water, preheating the combustion air, etc., and then is removed from dust by the gas treatment device f. , desulfurization, denitrification, etc. are performed, and the structure is such that it is released into the atmosphere from the chimney g.

In addition, coal contains 10 to 20%wt when drained.
% moisture, of which the moisture adhering to the surface is 5 to 10 wt%, and when piled up in the open,
The amount of moisture increases due to precipitation and, in cold regions, due to freezing of precipitation, which becomes the main cause of coal adhesion, sticking, and clogging in coal storage, coal transportation, and other equipment.

However, conventional dry coal (moisture removal) is done to improve the crushing efficiency of the crusher and the combustion efficiency of the boiler, and is carried out before or during crushing. Moisture adhering during coal production or open coal storage is retained as is, causing coal adhesion, sticking, or blockage in silo coal storage equipment (c), transfer equipment (t) (conveyors, hoppers, chute, etc.), coal bunkers (d), etc., and impairing their operation. For example, as shown in Fig. 2A and B, the silo c is equipped with a high-pressure air compressor c ₁ , air piping c ₂ , operating valves c ₃ and c ₃ , and an air jetting shell c _{4 .} , c ₄ ... to inject air into the lower part and lower hopper part of silo c, or by means such as poking with a stick or hitting with a hammer at appropriate times. Therefore, measures have been taken to remove coal adhesion, sticking, blockage, etc., but the former type of equipment has the disadvantage of being large-scale and covering a wide area, resulting in significantly high equipment costs and running costs.
In addition, the latter method requires a great deal of labor and time, and there is a risk that coal adhesion may not be removed properly, resulting in blockage, and if a blockage occurs, combustion will occur because there is no other equipment with a large buffer function. This has the disadvantage that the amount of fuel supplied to the equipment (boiler) is significantly reduced and even stopped, which seriously impedes the coal supply function.

The present invention was developed in order to eliminate the above-mentioned drawbacks of conventional coal supply devices, and is a coal supply device that crushes coal with a crusher and supplies it to a combustion device such as a thermal power plant. , further upstream of the coal supply of a device such as a silo coal storage device or a coal bunker disposed upstream of the coal supply of the pulverizer in the coal supply device, the coal is dehumidified by the sensible heat of the exhaust gas in the combustion device. It is characterized by the provision of a device for removing adhering water, and its purpose is to remove adhering moisture from coal at a stage before the various devices that cause coal adhesion, sticking, clogging, etc. in the coal feeding device, and to remove the adhering water The object of the present invention is to provide a coal supply device for a thermal power plant, etc., which has an enhanced coal supply function by adding a relatively small device with low running cost by utilizing the sensible heat of combustion exhaust gas.

The present invention has the above-mentioned configuration, and the sensible heat of the exhaust gas in the combustion device is provided further upstream of the coal supply of a device such as a silo coal storage device or a coal bunker disposed upstream of the coal supply of the pulverizer in the coal supply device. Since we are equipped with a coal adhesion water removal device that dehumidifies the coal, the adhesion water on the coal in various equipment such as the silo coal storage device, transfer device, coal bunker, etc. in the coal supply equipment is significantly reduced, and the coal adhesion water in the coal supply equipment is significantly reduced. Coal adhesion and adhesion are generally and efficiently reduced, blockages are eliminated, and the coal supply function is significantly improved.Compared to conventional examples in which a device for removing coal adhesion and adhesion is installed in the above-mentioned devices, this coal adhesion water removal method The equipment is significantly downsized, and by utilizing the sensible heat of the exhaust gas, equipment costs and running costs are significantly reduced.

Embodiments of the present invention will be described below with reference to the drawings.

A first embodiment of the present invention is shown in FIGS. 3 and 4,
This embodiment is a case where a silo coal storage device (including indoor coal storage) is installed, and in the figure 1 is a coal lifting device, 2 is a coal storage device.
3 is a coal adhering water removal device, 3 is a silo coal storage device, 4 is a coal adhering water removal device,
5 is a coal bunker, a crushing device, and a combustion device; 5 is a gas processing device for exhaust gas dust collection, desulfurization, and denitrification; 6 is a
is a chimney, and a transfer device 7 consisting of a conveyor, hopper, chute, etc. is provided between each of the devices,
The pumped coal is sent by a transfer device 7 from the coal lifting device 1 to a coal adhering water removal device 2, a silo coal storage device 3, a coal bunker, a crushing device, and a combustion device, that is, a boiler 4, in this order. At the same time, the exhaust gas from the combustion device, that is, the boiler, is supplied from the gas treatment device 5 to the coal adhering water removal device 2 through the pipe 8, and its sensible heat is used for removing the coal adhering water, and then the exhaust gas is recycled again. The structure is such that it is introduced into the gas treatment device 5 through a pipe line 9.

In addition, as shown in FIG. 4, in the coal adhesion water removal device 2, the coal transported by a transfer device 7, that is, a conveyor, is once stored in a hopper 21, and then transferred in the direction of the arrow (to the right in the figure). It is cut out onto a conveyor 22 made of a lattice, moves in the direction of the arrow, and is sent to the rear transfer device 7 on the right side of the figure.
The coal on the conveyor 22 is stored in a first chamber A, a second chamber B, and a third chamber, which are divided in the length direction surrounding the conveyor 22.
It passes through the hood 23 forming chamber C, is heated in the first and second chambers A and B to remove attached moisture, and is heated in the third chamber.
The exhaust gas from the combustion device passes through the pipe 8 and enters the lower inlet 23.
It enters from a and rises in the second chamber B to reach the discharge port 23b, and from the discharge port 23b the lower inflow port 23
C, it rises inside the first chamber A and reaches the discharge port 23d.
During this time, the coal is heated and its adhering water is removed, and the exhaust gas from the exhaust port 23d is introduced into the cooler 24 at the inlet 23e provided at the lower side of the third chamber and cooled. Afterwards, the coal being transported is cooled by rising inside the third chamber C and discharged to the discharge port 23f.
The structure is such that the gas is discharged through the pipe 9 and introduced into the gas treatment apparatus shown in FIG. 3 for gas treatment.

Incidentally, the exhaust gas from the combustion device flows from the pipe 8 to the inlet 23c, the outlet 23d, the inlet 23a, and the outlet 2.
It is also possible to send them in the order of 3b.

The first embodiment shown in Figs. 3 and 4 has the above-mentioned configuration. For example, in a 100 x 10 ⁴ KW thermal power plant, coal with a calorific value of about 6000 Kcal/Kg is consumed at about 400 t/h. The amount of exhaust gas is
3.5×10 ⁶ Nm ³ /h (however, the amount discharged from the coal bunker or silo is about 1000t/h), and the exhaust gas is often released into the atmosphere at a temperature of about 150°C. In addition, the exhaust gas contains about 10% moisture and has a dew point of about 70 to 130 degrees Celsius.
The sensible heat possessed by the exhaust gas has a specific weight of 1.3Kg/
Nm ³ and specific heat of 0.32 Kcal/Kg°C per 1°C is 3.5×10 ⁶ ×1.3×0.32 = 14.5×10 ⁵ (Kcal/h°C).

The coal used has 10-20% moisture,
The moisture content on the surface of coal, which causes blockages in coal transportation, coal storage, and other equipment that is the problem of this invention, is 10%.
If it is within 5% or less, the blockage can be eliminated. Therefore, the amount of heat required to remove about 5% of the moisture from the amount of consumed coal is 1000 x 10 ³ x 0.05 x 570 = 28.5 x 10 ⁶ Kcal/h, assuming the enthalpy required for evaporation is 570 Kcal/Kg. be.

Therefore, if the entire amount of exhaust gas is used, it is only necessary to lower the exhaust gas temperature by 20℃, and if the temperature drop of the exhaust gas is 100℃, approximately 20% of the exhaust gas, or 7.0×10 ⁵ Nm ³ /h, will be reduced. In this case, approximately 20% of the amount of exhaust gas released into the atmosphere is extracted, the exhaust gas is guided to the inlet 23a in FIG. 4, and sent to the gas treatment device 5 again. The desired objective can be achieved by simply lowering the exhaust gas temperature on the 5th side by 9°C.

In addition, the exhaust gas in the combustion equipment, i.e., the boiler's feed water preheater (not shown), is about 400℃, so the temperature drop is 300℃, and when air is extracted from that part, the amount of extracted air is 1/3 of the above value, or about 6%. The coal adhering water removal device can be further downsized. The coal in the third chamber C is cooled to a temperature at which there is no risk of spontaneous combustion.

Therefore, according to the first embodiment, the coal adhering water removing device 2 is provided at the upstream side of the coal supply, that is, at the previous stage of the silo coal storage device 3, and in order to remove the adhering water from the coal by the device 2, the coal adhering water removing device 2 is installed. By reducing the moisture content of the coal, it is possible to efficiently reduce coal adhesion and sticking in the transfer device 7, silo coal storage device 3, coal bunker, and crushing device 4, thereby preventing clogging and significantly improving the coal supply function. The coal adhesion water removal device 2 is significantly smaller in size than the conventional example, and utilizes the sensible heat of the exhaust gas, so equipment costs and running costs are significantly reduced. Therefore, the combustion device, ie, the boiler, can operate smoothly and its efficiency is greatly improved.

Next, FIG. 5 shows a second embodiment of the present invention, which is a case of open pile coal storage.
In the case of this embodiment, a coal lifting device 1, a transfer device 7, an open pile coal storage device 30, a transfer device 7, a coal adhering water removal device 2, a transfer device 7, a coal bunker, a crushing device and a combustion device 4, a gas processing device 5 , and the arrangement of the chimney 6. In addition to the specific example shown in FIG. 4, the coal adhering water removal device 2 of this embodiment may also have a structure as shown in FIGS. 6 and 7. .

FIG. 6 shows another embodiment of the coal adhering water removal device, in which coal is supplied from a feed pipe 41, introduced onto the lattice floor 42 of the tank 40, and supplied from the pipe 8 into the inlet 43 on the lower side of the tank 40. The discharged exhaust gas is transferred to the tank 4.
The coal rises through the coal in the 0, flows through it, heats it, removes water, and then is sent to the gas treatment device 5 via the upper exhaust port 44 and the pipe 9. On the other hand, the water-removed coal flows through the exhaust port 45. It has a fluidized bed structure where it is taken out from the water.

In addition, FIG. 7 shows another embodiment of the coal adhesion water removal device, in which coal is supplied from an upper chute 51 into a tank 50, and is banded and flowed down into a lower hopper.
The exhaust gas from the pipe line 8 is supplied from the header 52 into the lower part of the coal in the tank 50, and after the coal is heated and water removed, it is discharged from the exhaust port 54 and sent to the gas processing device 5, while the water is removed. Coal is in the lower damper 55
It has a hopper type structure that allows it to be taken out.

Therefore, in the other embodiments shown in FIGS. 6 and 7, the same effects as in the first embodiment shown in FIGS. 3 and 4 can be obtained except for the cooling function. Note that the devices shown in FIGS. 6 and 7 can also be applied to the coal adhesion water removal device 2 shown in FIG. 3.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

Figure 1 is a mechanical diagram showing a conventional coal supply device for a thermal power plant, etc., Figure 2 is a mechanism diagram showing an example of a device for removing coal adhesion and sticking in the silo coal storage device shown in Figure 1, and Figure 3 is a mechanical diagram showing an example of a device for removing coal adhesion and sticking in the silo coal storage device shown in Figure 1. FIG. 4 is a mechanism diagram showing an embodiment of the coal adhering water removal device shown in FIG. 3; FIG. 5 is a mechanism diagram showing a second embodiment of the invention. Mechanism diagram of coal supply device, No. 6
Fig. 7 and Fig. 7 are mechanical diagrams showing other embodiments of the coal adhering water removal device. 1: Coal lifting equipment, 2: Coal adhesion water removal equipment, 3:
Silo coal storage device, 4: Coal bunker, crushing device,
Combustion device, 5: Gas processing device, 7: Transfer device,
8, 9: Pipeline, 30: Open pile device.

Claims (1)

[Claims] 1. In a coal supply device that crushes and supplies coal to a combustion device such as a thermal power plant using a crusher, a device such as a silo coal storage device or a coal bunker installed on the coal supply upstream side of the crusher in the coal supply device A coal supply device for a thermal power plant or the like, further comprising a coal adhering water removal device for dehumidifying the coal by sensible heat of the exhaust gas in the combustion device, on the upstream side of the coal supply.