GB2089963A

GB2089963A - Pulverulent Coal Burner

Info

Publication number: GB2089963A
Application number: GB8041063A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-12-22
Filing date: 1980-12-22
Publication date: 1982-06-30

Abstract

For complete and efficient burning coal is pulverized and fully mixed with fresh air before entering the combustion chamber 1 of the burner. By providing a conventional oil burner with a primary blower 8 which is for fully dispersing and suspending the pulverized coal in the sufficient fresh air, the improved oil burner can also use pulverized coal as a fuel. <IMAGE>

Description

SPECIFICATION Process and Apparatus for Producing Suspension of Fine-Grained Coal in Air, Acting as a Fuel for Burner The present invention is related to a process for producing a suspension of fine-grained coal in air, more particularly, to a process for producing an easily combustible gas-like fuel from the pulverized coal to be used in the burner.

Traditionally, for enhancing the burning efficiency of the coal, the coal was firstly cracked to be coarse-grained before it discharges to the combustion chamber of the burner. Because of the size of coarse-grained coal, it can not suspend in air. Therefore even with the aid of the secondary fresh air blower, the coarse-grained coal can not be burnt out completely. Therefore some of coarse-grained coal remains unburned and falls down to the bottom of the combustion chamber.

Furthermore, the burner which uses the coarse-grained coal as a fuel is relatively bulky.

According to the present invention, a process for producing a suspension of fine-grained coal in air to act us fuel for a burner, comprises the steps of, dispersing pulverized coal in sufficient flowing fresh air to make an easily combustible gas-like fuel before entering into the combustion chamber of a burner, and blowing the easily combustible gas-like fuel into the combustion chamber.

Accordingly, a primary blowing mixer which carries out the above process, is provided between a pulverized coal feeder and the combustion chamber. The blowing mixer comprise a blower which has an inlet and an outlet; a T-shaped pipe, one end thereof communicating with the inlet of the blower, the other end thereof communicating the feeding mouth of the pulverized coal feeder, another end thereof remains free for pumping in fresh air as the blower is on, as well as permitting part of the pulverized coal which is not suctioned by the blower falling out.

It is an object of the present invention to provide an easily combustible gas-like fuel, in which the pulverized coal if fully suspended in the fresh air before it enters into the combustion chamber, which can be burned more efficiently.

It is an other object of the present invention to provide an easily combustible gas-like fuel which can be handled as easily as liquefied gas.

It is another object to provide a burner, which is provided with a blowing mixer, thereby the pulverized coal can be burned more efficiently in the combustion chamber.

These and other objects of the present invention will be more apparent by illustrating preferred embodiments with reference to the following drawings, in which, Fig. 1 is an illustrating schematic view of a preferred embodiment producing and using an easily combustible gas-like fuel according to the present invention; and Fig. 2 is a perspective view of an embodiment according to Fig. 1.

As shown in Fig. 1, a blowing mixer which is provided between a combustion chamber 1 and a pulverized coal feeder 6 of coal silo 5 comprises a blower 8 and a T-shaped pipe 1 6. The outlet of the blower 8 communicates with a conical casing 10 at the intake 15 thereof and the inlet of the blower 8 communicates with one end of the Tshaped pipe 1 6. The other end of the T-shaped pipe 1 6 communicates with the mouth of the pulverized coal feeder 6. Another end 7 thereof remains free for pumping in the fresh air. A pulverized coal collector 1 7 is positioned under the free end 7. As the blower 8 starts to run, the pulverized coal which falls through the feeder 6 and the fresh air from the free end 7 will be suctioned together into the blower 8.In the blower 8, the pulverized coal will be fully suspended in the flowing fresh air before it leaves the outlet of the blower 8. As a valve 31 is regulated to decrease the flowing rate of the suspension of pulverized coal in air, part of the pulverized coal which can not be suctioned into the blower will fall down to the collector 1 7.

For illustrating the easy burning and simple operation of the suspension of pulverized coal in air, a conventional oil burner which is provided with the blowing mixer will be explained thereafter.

The easily combustible suspension of pulverized coal in fresh air which has been blown into the conical casing 10 will further discharge into the combustion chamber 1 through an annular opening 1 3. As a igniter 9 ignites, the suspension of pulverized coal in air will combust furiously. With the aid of fresh air from a secondary blower 4, it will burn further efficiently and completely.

As it is intended that the oil is burned together with the suspension of the pulverized coal in air.

The oil fuel can be injected into the combustion chamber through a nozzle 14 from an oil supply pipe 2. At the exhaust of the combustion chamber 1, a cyclone 11 with a chimney 12 is provided for cleaning the exhaust air before it puffs to the atmosphere.

The following test conditions and combustion results are obtained from the embodiment, as shown in Fig. 2 which is burning the gas-like fuel of pulverized coal suspended in fresh air according to the present invention. These results prove the suspension of pulverized coal in fresh air is an easily combustible and handled fuel, and can be used as convenient as the liquefied gas.

Test condition 1. Area of heat transfer: 46m2 2. Size of combustion chamber: diameter 840 mmxlength 2200 mm (Morrison type) 3. The blower of the blowing mixer: a. power 3 HP b. blowing quantity c.a. 1 200m3/h c. pressure of blowing 1 50 mmaq.

4. Second blower: a. power 5 HP b. blowing quantity c.a. 2400m3/h at max.

c. blowing pressure 250 mmaq.

5. Liquefied gas igniter: transient voltage 6000V 6. Quality of pulverized coal: a. size 100 meshes b. Heat capacity c.a. 6200 kcal/kg Combustion conditions 1. Regulating valve 31 to permitting c.a. 400 m3/h of blowing quantity through the intake 1 5.

2. The discharge of the suspension of pulverized coal in fresh air into the conical casing 10 is 210 kg/h (calculating based on the pulverized coal onlu) 3. The blowing quantity of the fresh air from the secondary blower 4 into the combustion chamber 1 is regulated to be 1400m3/h. (The blowing pressure of conical casing 10 is 240 mmaq., and that of the combustion chamber- is 60 mmaq. The differential pressure of the conical casing 10 and combustion chamber 1 is 180 mmaq.) 4. Temperature of the combustion chamber 1 is 80001 2000C.

5. Temperature of the exhaust air is c.a. 2300C at max.

6. CO2 content of the exhaust air is c.a. 20%.

7. Color of the flame: reddish yellow - white yellow.

8. Ash content: 1 7 kg/h from the collector of the cyclone 11. 18 kg/h from the combustion chamber 1 9. Quantity of steam generation: c.a. 1400 kg/h.

10. The exhaust of the chimney 12: slightly yellow in the beginning, turn white after 15 minutes.

By improving the conical casing and enlarging the length of the combustion chamber, the burning of the suspension of pulverized coal in fresh air can be more efficient than that of the afore-mentioned embodiment.

With the invention thus explained, it is obvious that modification and variations thereof can be made without departing from the spirit of the present invention. It is intended that the scope thereof be defined by the appending claims.

Claims

1. A process for producing a suspension of fine-grained coal in air to act as fuel for a burner, comprising the steps of, dispersing pulverized coal in sufficient flowing fresh air to make an easily combustible gas-like fuel before entering into the combustion chamber of the burner, and blowing the easily combustible gas-like fuel into the combustion chamber.

2. A process as claimed in Claim 1, in which the size of pulverized coal is preferrably smaller than 100 meshes.

3. A burner which uses a suspension of finegrained coal in fresh air as a fuel, comprising: a blower which has an inlet for pumped-in pulverized coal as well as air, and an outlet; a combustion chamber which has a fuel intake communicating with the outlet of the blower, and an exhaust; a pulverized coal feeder communicating with the inlet of the blower.

4. A burner as claimed in Claim 3, further comprising, a T-shaped pipe, one end thereof communicating with the inlet of the blower, the other end thereof communicating with the pulverized coal feeder, and the remaining end thereof communicating with the atmosphere, whereby part of the pulverized coal out of the feeder, which is not pumped into the blower, will fall out through the free end.

5. A burner as claimed in Claims 3 or 4, further comprising a cyclone which is provided at the exhaust of the combustion chamber, whereby the exhaust air is cleaned before being discharged to the atmosphere.

6. A burner as claimed in Claim 4, further comprising a pulverized coal collector positioned under the free end of the T-shaped pipe, whereby the pulverized coal falling through the free end can be collected and re-used.

7. A burner, which uses a suspension of finegrained coal in fresh air as a fuel, substantially as hereinbefore described with reference to the accompanying drawings.