JPS5899612A - Furnace and its operation method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a furnace and method of operating the same. In this case, the furnace comprises at least one coal pulverizer and a first pulverizer which is provided with a classifier at the outlet end and which is supplied with hot air.
a first pulverized coal ζ group connected to the outlet end of the first classifier and into which pulverized coal is directly injected;
- It is of the form consisting of -suto attached to -suto.

Gas, oil or pulverized coal for ignition differs in consistency and/or composition from the pulverized coal supplied to It can be considered as fuel. In the case of direct injection combustion furnaces, the combustion chamber of the furnace must have a relatively high combustion temperature. This combustion temperature may vary, e.g.
This is the temperature at which Q'C is reached. With direct injection combustion, individual pulverized coal burners can only operate at partial loads of less than 60 inches.

Therefore, when operating a furnace equipped with many pulverizers and many pulverized coal 2-stocks of direct injection combustion type connected to their outlets/ends at partial load, this partial load is The powder is supplied by operating a pulverizer. The minimum mill capacity is determined not only by the way the mill operates, but also by the minimum rotational speed for the bunker feeder attached to the mill.

Furnaces with intermediate storage are also known, in which a pulverized coal funnel fed with one pulverizer flue gas and having at least one Z filter is connected at the outlet end to the mill shifter. The pulverized coal from the pulverizer is intermediately stored in this pulverized coal tanker. A number of pulverized coal nodules are connected to the exposed end of the pulverized coal tanker via adjustable feed devices. As in the case of direct injection combustion furnaces, each nozzle is attached to the pulverized coal nozzle (main and nozzle). In the intermediate storage equation, ・ζ− group unit ・
When operating a furnace with different burner heights, one pulverized coal burner group is connected after preheating. That is, the combustion room temperature must be raised to a high temperature that ensures the ignition of the main nozzle. When the load fluctuates, all ζ-groups with different heights are cut off.

The object of the invention is to provide improvements in a furnace of the type mentioned at the outset with regard to its operation and partial load.

For this purpose, the furnace according to the invention is equipped with at least one second pulverizer, which is supplied with flue gas and has a classifier connected to its outlet end. , at least one pulverized coal bunker having at least one filter is connected to the outlet end of this second classifier, and a second pulverized coal, S-type coal bunker, is connected to the outlet end of this pulverized coal bunker. These second pulverized coal groups are connected via at least one adjustable feeding device? The pilot and ζ- are connected to each other.

The invention also relates to a method of operating such a furnace, which is characterized by the following points: That is, when starting the The intermediately stored pulverized coal is supplied to at least one burner of the group of It supplies pulverized coal to the area.

Conventionally, there is no known example of using a direct injection combustion type pulverizer for pulverized coal together with an intermediate storage type pulverizer for pulverized coal in Zeila equipment. Rather, the art has opposed the simultaneous use of direct injection combustion and intermediate storage, despite the unexpected and significant operational advantages that can be achieved for variable load, six-warp plants.

According to the present invention, a pilot ζ-s is also attached to the second group of pulverized coal ζ-s (main d-s). In this case, each of the first and second groups of pulverized coal and ζ-slots can be attached with one slit nose, but the number of pulverized coals and ζ-slots can also be reduced. You can also do that. In addition, the pulverized coal nozzles of the second Sena group have 1
It is advantageous to attach two ξ pilots and ζ-s.

In the case of the furnace according to the invention, all the pulverized coals of the second S-group, S-s, can be connected in common to one adjustable feed device. Even in this minimal case, pulverized coal
As long as the pulverized coal is supplied from the pulverizer, it can be supplied to the pulverizer regardless of the operation and output of the second pulverizer.

In the maximum case, pulverized coal of the second ζ-group
- each is associated with an adjustable feeding device. In this case, after the furnace is started after reaching a low combustion chamber temperature, the pulverized coal of the second gunner group is
They can be connected continuously one by one or in small units. In this way, the consumption of fuel, such as oil, is reduced. This is because the burners can be connected one after another or in small units at a low combustion air temperature.

The first classifier is a fixed classification type mill shifter, and the second
It is particularly advantageous if the classifier is a variable classifier shifter. This is because it is possible to change the particle size of the pulverized coal used to operate the pulverized coal ζ-su, in short the main ζ-su. For example, if the first classifier operates with a residue of 25% with a particle size of 90 μm, it is appropriate to adjust the variable shifter to produce a residue of 5% to 25% with a particle size of about 90 μm. be. When using a centrifugal shifter, the classification can be changed by adjusting the rotational speed of the drive device.

This type of construction of the second classifier, ie the second shifter, is particularly advantageous in the following embodiments. Thus, according to this embodiment, the gas outlet of the filter attached to the pulverized coal tanker is provided with a pulverized coal filter connected at the outlet end, the pulverized coal outlet of the pulverized coal filter being connected to at least one pulverized coal filter. It is connected to the pulverized coal
This ultra-fine coal burner itself is connected via at least one feeding device to at least one of the pulverized coal main burners, or is integrated in or close to one of these pulverized coal main burners. The pulverized coal is connected to at least one pulverized coal slot located at the In the case of such a configuration, by adjusting the classification of the chic attached to the second pulverizer, the distribution of pulverized coal to the pulverized coal pile and the ultra-fine coal pile can be determined, for example, 80 to 90 pulverized coal.
% by weight can be distributed to the pulverized coal bunker, and 20 to 10% by weight can be distributed to the pulverized coal bunker as ultrafine coal for ignition. The ultrafine coal thus has a particle size of 90 μm and a residue of less than 10 μm.

If extremely pulverized coal is used as the fuel for the pulverized coal/ζ-su as the main ζ-su, the required combustion air temperature can be lowered even further.

After starting the furnace, pre-ignition of the ζ-su by direct injection combustion can be carried out during operation. For this purpose,
The entire pulverized coal .zeta. group of the second .zeta. group can be operated in small units, preferably one at a time, with pulverized coal, very pulverized coal or mixtures thereof.

If several pulverizers with direct injection combustion are attached to a second pulverizer with intermediate storage, satisfactory operation of the furnace is also possible.

In this case, the height of the burners of the second burner group is the same as the height of the burners of the first burner group of the direct injection combustion type and the height of the burners of the third burner group of the direct injection combustion type.
・It should be located between the height of the path and the height of the ζ− group.

The invention will now be explained with reference to the illustrated embodiment.

The four pulverized coal burner groups 3, 4, 5.6 each have eight pulverized coal burners and are mounted in the combustion chamber 1 of the I-burner 2. The pulverized coal burners of the pulverized coal, V-S group 3.4.6 are numbered 7, and the pulverized coal burners of the pulverized coal burner group 5 are numbered 8. As can be seen from FIG. 2, the pulverized coal burners 7.8 of the pulverized coal groups 3, 4, 6.5 are arranged at different heights vertically, and one pulverized coal burner 7.8
- Half of the burners in the group are arranged on the front wall 2a of the zeira 2, and the remaining half of the burners are arranged on the back wall 2b of the zeira 2. The height of pulverized coal group 5 is located between the height of pulverized coal group 6.

The pulverized coal tanks 7, 8 are equipped with a common fuel tank 9 designed as an oil burner.

The flame path gases from the combustion chamber 1 are discharged by a suction blower 13 via a superheater 10, a hot gas valve 11 and an electrostatic precipitator 12. A portion of the flame path gas at a temperature of about 420'C is taken out from between the superheater 1o and the hot gas valve 11 by a branch circuit 14 and sent to the centrifugal shifter 16 as drying and deactivation reservoir gas for the grinding reservoir. The powder is supplied to a pulverizer 15 equipped with a pulverizer 15. The outlet of this pulverizer 15 is a centrifugal shifter 1°6
It is connected to the. For the pulverizer 15: ff-rudnka 1
Coal is supplied from 7 to a supply device 18.

The same applies to another fine powder machine 20 equipped with a mill shifter 21.
- Coal is supplied via a supply device 19 to the lupanka 17 and a separate nocturnal force 17'.

Dry air for grinding is supplied to the pulverizer 20 in the following manner. Fresh air is sucked in by a fresh air blower 22 and supplied to a booster blower 24 via a duct 23.

A part of the air stream is fed directly to the pulverizer 20 via the duct 25, and the remaining air stream is supplied to the duct 2 after being preheated in the preheater 26 and then further heated in the hot gas valve 11.
7 through the duct 25. supplied within.

The ratio of cold fresh air to heated fresh air is adjusted so that the heat content of the dry air for pulverization supplied to the pulverizer 2o corresponds to the amount of coal to be pulverized in the pulverizer 20. be done. The temperature inside the duct 27 may be approximately 320°C.

The pulverized coal outlet from the mill shifter 21 leads to a two-outlet type branch junction box 28', and the outlet of this branch junction box 28' is connected to the pulverized coal via four-outlet type branch junction boxes 29' and 30'. It is connected to the pulverized coal burner 7 of the mana group 3. For the sake of simplicity, the branch connection box is omitted in FIG. 2, and the pulverized coal burner 7 is shown as if it were directly connected to the pulverizer 30. The pulverized coal burner groups 6, 4 are similarly supplied with pulverized coal from the pulverizers 30, 31 via branch junction boxes 28 and 29 (see FIGS. 1 and 2). Fine powder machine 2
0.30.31 is a direct injection combustion type.

The pulverized coal outlet from the centrifugal shifter r6 is connected to four pulverized coal separators 33 (only one of which is shown in FIG. 1. If the coal separator 33 can process the entire amount of pulverized coal, other pulverized coal separators are not necessary). This pulverized coal separator 33
The outlet of the pulverized coal is connected to the main pulverized coal 9-inker 35 through a two-wheel valve 34 to maintain the deactivation of the pulverized coal.

For optimal operation of the furnace according to the invention, this main pulverized coal bunker 35 is provided with a large number of outlets 36, the number of which is equal to the number of pulverized coal burners 8 of the pulverized coal mana group 5. Compatible. In other words, when the number of pulverized coal marches in the pulverized coal burner group 5 is eight, eight outlets of the main engine pulverized coal 7 burner 35 are also required (see FIG. 1). This outlet 36 is then connected via a supply device 37 to a primary air stream 38 which leads to each pulverized coal burner 8 .

As can be seen in FIG. 1, fresh air is supplied by one primary air blower 39 for each of the four primary air .xi. blades 38.

FIG. 2 shows a low-output embodiment according to the present invention, in which the two pulverized coal burners of the pulverized coal burner group 5 each have a primary air supply device 38 and a supply device (see FIG. 2). (not shown) to the main pulverized coal bunker (not shown in FIG. 2) and therefore, unlike in the embodiment of FIG. In the embodiment shown in FIG. 2, the pulverized coal marches 8 are controlled in pairs.

A duct 40 branches off from between the packet wheel valve 34 and the main pulverized coal bunker 35 , and this duct 40 communicates with a pulverized coal storage bunker 41 .

The gas outlet of the pulverized coal separator 33 is connected to a gas filter 43 via a compressor 42, and this gas filter has two very pulverized coal outlets as shown. This ultra-fine coal outlet is connected to an ultra-fine coal bunker 45 via a duct 4. The ultra-fine coal bunker 45 includes a duct 46, a supply device 47, and one two-outlet branch junction box 47'.
It is connected to the primary air/ξ Eve 38 via. The number of supply devices 47 corresponds to the number of supply devices 37, or more than one primary air ξ iso can be connected to the outlet of the supply device 47. Furthermore, the supply device 47 supplies primary air
Through another duct 38' guided from the pulverized coal, the pulverized coal was installed. eIlot, w
- The ultra-fine coal may be grafted into the pulverized coal into the separate section of the pulverized coal/march 8 (integral with the .xi. pilot) as fuel ultra-fine coal. This no ξ
1] is shown in FIG. moreover,
It is also possible to guide ultra-fine coal to pulverized coal, which is not integrated with the two-wheeled coal.

The filtered gas passes through the gas filter 4 at a temperature of approximately 100°C.
3 through duct 48 to duct 1, where it is mixed with the hot flame gas in duct 14. Fine powder machine 15
The temperature of the drying gas supplied into the grinding tank is 420℃.
The desired temperature is adjusted between 100°C and 100°C. If necessary, part of the gas from the gas filter 43 ix branch pipe 9
The gas is supplied to a gas nozzle (not shown) through the gas nozzle (not shown). Furthermore, this gas is pulverized coal? It is also possible to supply pulverized coal to one of the groups 3, 4, 5 and 6/2.

In order to deactivate the main pulverized coal bunker 35 and the pulverized coal storage bunker 41, the hot flame gas at approximately 130°C is taken out from the downstream of the suction blower 13, and the inert gas pipe 50 and another suction blower 51 are taken out. It is also possible to supply the pulverized coal to the pulverized coal storage bunker 41 via the pulverized coal storage bunker 41.

Furnace air is supplied through a duct 52. connected to the fresh air blower 22. Via the preheater 53 and the hot gas valve 11 it is fed to the combustion chamber l or to the pulverized coal burner group 3, 4, 5.6. Corresponding ducts are not shown for simplicity.

The centrifugal shifter 16 is equipped with a drive motor 16', so that the classification of the centrifugal shifter 16 is adjustable by varying the rotational speed. For example, the classification operation of the centrifugal sifter 16 can be adjusted so that the particle size is 90 μm and the residue is 5 to 25%.

Classification work of mill shifter 21: Particle size: 90 μm f25%
This is done in such a way that a residue of This is a constant size as the classification function of the pulverizer with shifter changes in relation to load, coal composition and pulverizer wear.

In an advantageous adjustment of the centrifugal shifter 16, 80% of the feed coal is fed as main pulverized coal to the main pulverized coal bunker 35 and/or pulverized coal storage bunker 41, and 20% to the very pulverized coal bunker 45.
is supplied as ultra-fine coal to

The furnaces described above offer various possible starting methods.

Firstly, by actuating one of the feed devices 47 the temperature of the combustion chamber l can be raised to such an extent that the ultra-pulverized coal fed to one of the pulverized coal burners 8 can be ignited. . When one of the pulverized coal marches 8 is ignited, the temperature of the combustion chamber 1 rises, and then the remaining pulverized coal marches of the pulverized coal burner group are sequentially connected. If the ignitability of the pulverized coal supplied into the main pulverized coal bunker 35 is extremely good, one pulverized coal burner 8 of the pulverized coal burner group 5 may be used, even if extremely pulverized coal is not used at a relatively high combustion chamber temperature. Can be fired in sequence. moreover,
It is also possible to supply the primary air sieve 38 with a mixture of ultra-fine coal and main pulverized coal.

The supply of main pulverized coal, very pulverized coal or a mixture of both is independent of the operation and/or efficiency of the pulverizer 15.

The operation of the pulverizer 15 is started when the required amount of flame path gas at the required temperature is obtained.

Advantageously, the pulverizer 30 injects pulverized coal directly into the pulverized coal manna 7 of the pulverized coal burner group 6 after the temperature of the combustion chamber has further increased by the pulverized coal burners of the pulverized coal burner group 5.
is activated first.

Then the pulverizer 20.3 for pulverized coal burner group 5 or 4
1 is still connected. In that case.

The mills 20, 30, 31 are preferably driven with 20% mill air.

In the embodiment shown in FIG.
Marches 8 are connected in pairs.

Whether each pulverized coal burner 8 of the pulverized coal burner group 5 is supplied with pulverized coal via its respective feeding device 37 (maximum)
, or whether pulverized coal is commonly fed (minimum) through a single feeding device 37, this is done independently of the operation and efficiency of the pulverizer 15, and in either feeding type there is no pulverized coal in the pulverized coal bunker. Charcoal is stored.

When the load changes from full load to partial load, if the pulverized coal bunker 35 is fully filled, first
The pulverizer output must then be adjusted to match the pulverized coal burner output, and if a pulverized coal storage bunker is provided, this pulverized coal storage bunker is fully filled.

In a furnace according to the invention with at least one pulverizer 15 of intermediate storage type and at least one pulverizer 2°, 30 or 31 of direct injection combustion type, an auxiliary ignition from pulverized coal burner group 5 is provided. This provides significant advantages in the operation of the zeira.

The main pulverized coal burner cannot operate at less than 60% of its efficiency, so in the case of pure direct injection combustion,
When the required load change for a single pulverized coal burner and one level falls below 60%, the pulverized coal burners of all levels must be shut off. Pulverizer 15. By storing the pulverized coal for an intermediate period in the pulverized coal manpower 35 and supplying it to the pulverized coal 9-8 unrelated to the pulverizer, the pulverized coal can be stored without shutting off all the pulverized coal burners 8 of the pulverized coal burner group 5. Auxiliary ignition is provided by a single pulverized coal burner or by a small unit of pulverized coal burners of the charcoal burner group 5.

The direction of the gas flow at the branch junction box of the duct is advantageously regulated for each line individually by a regulating valve (not shown).

One or more pulverizers 15 can be provided as direct injection combustion pulverizers.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of one embodiment of the invention, and FIG. 2 is a diagram of another embodiment of the invention. 1... Combustion chamber, 2... Ive, 3, 4, 5.6...
・Pulverized coal burner group, 7, 8...Pulverized coal burner, 9...
・Pilot burner, lO... superheater, 11... thermal waste valve, 12... precipitator, 13... suction blower, 1
4... Branch circuit, 15... Fine powder machine, 16... Centrifugal shifter. 17, 17'...Call Banka, 18.19...
Supply device, 20... Fine powder machine, 21... Mill shifter,
22... Fresh air blower, 23... Duct, 24...
Booster Zorowa, 25...Duct, 26...Preheater, 27...Duct, 28.28'...2 outlet type branch connection box. 29.29', 30'...4 outlet type branch connection box, 3
0.31... Pulverizer, 32... Raw outlet type branch connection box, 33... Pulverized coal separator, 34... 2-butt wheel valve, 35... Main pulverized coal bunker, 36 ... Outlet, 37... Supply device, 38... Primary air/ξ Eve,
39... Primary air blower, 40... Duct, 41...
...Pulverized coal storage bunker, 42...Compressor, 43...
Gas filter, 44... Duct, 45... Ultra-fine coal bunker, 46... Duct, 47... Supply device, 47
'...2 outlet type branch connection box, 48...Duct, 4
9... Branch pipe, 50... Inert gas pipe, 51...
Suction blower, 52... duct, 53... preheater

Claims (1)

[Claims] 1. At least one call hole/force and a first
a first pulverizer connected to the classifier and supplied with hot air, and a first pulverized coal connected to the outlet end of the first classifier into which pulverized pulverized coal is directly blown. - the pulverized coal d-slot is equipped with at least one second high-temperature flue, which is supplied with a pulverized coal pulverizer and at least one pulverized coal feeder with at least one filter connected to the outlet end of the second classifier; 2. at least two controllable feeding devices; is connected to the exit end of the pulverized coal tanker, and a specific number of the second group of pulverized coal tanks are connected to the outlet end of the feeding device. 3. The furnace according to claim 1, wherein a controllable feeding device is attached to each pulverized coal cell of the second group of pulverized coal cells. Furnace 04 according to claim 2, the first classifier is a fixed classification type mill-sick, and the second classifier is a variable classification type mill-sick, according to claims 1 to 3. 5. The furnace according to any one of claims 4 to 5, wherein the second classifier has a classifying member rotatable by a variable rotation speed drive device.
Furnace described in section. 6. A pulverized coal filter is connected to the gas outlet of the filter installed in the pulverized coal ζ/force, and the pulverized coal outlet of the pulverized coal filter is connected to at least one ultra-fine coal bunker, The amount of powdered coal itself is small (both 1
connected to at least one pulverized coal tank via one supply device, or at least one pulverized coal tank located in or near the pulverized coal tank.
The two pulverized coals are connected to one another,
A furnace according to any one of claims 1 to 5. 7. Pulverized coal, Zoirot, ζ-Suga 2nd pulverized coal, ζ-
7. The furnace according to any one of claims 1 to 6, wherein the furnace is arranged in the main ζ-space of the group. 8. The furnace according to any one of claims 1 to 7, wherein the pulverized coal storage/S 7 units are arranged in parallel to the pulverized coal storage unit. 9. In addition to the first and second pulverizers and pulverized coal powder group, multiple direct injection combustion type pulverizers and pulverized coal/ζ
9. Furnace according to any one of claims 1 to 8, comprising a group of -. 10. Any one of claims 1 to 9, wherein the pulverized coal nozzle group belonging to the pulverizer is of an intermediate storage type.
Furnace described in section. 11. The pulverized coals of the same group are arranged at the same height, and the second pulverized coal, ? The intermediate rail between the first pulverized coal ζ group rail of the direct injection combustion type and the level of another pulverized coal ζ group of the direct injection combustion type. A furnace according to any one of claims 1 to 10, wherein the gas discharged from the filter is guided to a second pulverizer or a gas burner. The furnace according to any one of items 1 to 5. 13. At the time of starting the furnace, the pilot ζ-gas is first ignited, and then, after reaching a certain combustion chamber temperature irrespective of the operation and output of the second pulverizer, at least one of the second pulverized coal nozzles is ignited. The intermediately stored pulverized coal is supplied to one - A method of operating a furnace, characterized in that pulverized coal is supplied to the ζ-s of the ζ-s group. 14. The ζ-s of the second pulverized coal ζ-s are operated individually one after the other via the associated feeding device or in sub-groups consisting of a specific sena number, according to the patent claim. Range 13th
015 of the method of operating the furnace described in Section 015, the method of operating the furnace described in Section 015 is based on at least one outlet of the small (second pulverized coal when operating with two direct injection combustion type pulverized coal S groups) ζ group. 15. A method for operating a furnace according to claim 13 or 14, which ignites an illot flame. 16. Supplying the pulverized coal, extremely pulverized coal, or a mixed coal thereof drawn out from the first pulverizer to the burners of the second 97th group;
A method for operating a furnace according to any one of claims 13 to 15.