KR850000686B1 - A burner for burning pulverized fuel - Google Patents

Abstract

A burner to burn pulverized fuel comprises a combustion chamber, an ignition chamber connected to the combustion chamber and equipped with a lighting apparatus like a distribution tube, and an apparatus to supply a mixture of fuel and compressed air, which is connected to the inside of the combustion chamber and is located between the combustion chamber and the ignition chamber.

Description

Burner for Differential Fuel Combustion

1 is a longitudinal cross-sectional view of the burner according to the present invention.

2 is a sectional view taken along the line II-II of FIG.

The present invention relates to a burner for differential fuel combustion, specifically speaking, a combustion chamber and an ignition chamber connected to the combustion chamber and provided with an ignition device, an inlet connected to the ignition chamber for supplying powder and conveying air, and an ignition chamber and a combustion chamber It relates to a burner composed of a device for supplying combustion air which is located approximately in the connection between and connected into the combustion chamber.

In such burners, long flames that could only be ignited with difficulty are eliminated by providing one or more throttles at a relatively short distance from the inlet of the feed pipe for the mixture of powder and conveying air. This throttle creates an irregular turbulence in the already ignited fuel stream, allowing the components to mix better. The use of throttles actually contributes to a significantly shorter flame, which results in a more compact device, but has the drawback that the distribution of the mixture cannot be optimally uniform when it hits the throttle. As a result of this incomplete distribution, the combustion temperature and combustion are not maximized and the flame control range is relatively small.

It is an object of the present invention to address this drawback.

According to the present invention, the burner of the above-described type is characterized in that the inlet ends in the distribution pipe, and the surface of the distribution pipe is provided with a plurality of openings.

A mixture of a small amount of powder and conveying air (eg 10%) reaches the ignition chamber through an opening in the distribution tube at the beginning of the distribution tube facing away from the combustion chamber, where a relatively small ignition flame Is ignited by This ignition propagates through the mixture supplied through the remaining openings, so that the powder is ignited in an amount stoichiometrically related to the amount of carrier air. Thus, a small amount of powder is initially heated to the ignition temperature and is ignited by the ignition flame, so that the amount of the ignited powder is then gradually increased to maintain the temperature at a high temperature. Only when the combustion chamber is reached is the remaining amount of combustion air supplied and the already ignited mixture is combusted with a relatively short hot flame. In the combustion chamber, the mixture is very disturbed so that good mixing is achieved. Optimum distribution is achieved by using a series of openings in the pipe without the control plate downstream of the pipe. Combustion can be enhanced to over 98%. The flame becomes hot and short.

The mixture flows as much as possible through the opening in the distribution tube into the ignition chamber. In particular, when the distribution tube has an open end, the inlet preferably comprises a device for imparting rotational motion to the mixture of powder conveying air along the wall of the distribution tube in which the openings are formed.

The device for imparting a rotational motion comprises a guide connected tangentially into the distribution tube. This guide does not contain moving parts to be worn. However, it is not excluded to use a rotating shaft having eggs centrally mounted in the distribution tube.

When the end of the distribution pipe facing the combustion chamber is open and fully supplied to the ignition chamber through the opening in the mixture fin distribution pipe, a suction effect occurs at the open end, and the flame enters the distribution pipe. This has a beneficial effect on ignition.

By using an exchangeable distribution pipe, the shape of the opening can be adapted to the relevant situation (the nature of the powder, the required capacity, etc.).

In order to advance the ignition advantageously, it is preferable to select the shape of the openings in the distribution pipe and to increase the surface area occupied by these openings in the direction of the combustion chamber.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Exemplary burners for burning fine fuel include a combustion chamber 1, an ignition chamber 2 connected to the combustion chamber, a distribution chamber or distribution tube 3 mounted therein, and a powder (e.g. finely divided lignite or coal). ) And a supply line 5 for supplying a mixture of air for transportation. This supply line is connected into the distribution pipe by a tangential guide 4.

Since the combustion chamber 1 is elongated, it forms a concentric annular channel 6 with respect to the ignition chamber 2, which serves as a supply conduit for combustion air to the combustion chamber 1. An annular plate 7 is provided between the combustion chamber 1 and the annular channel 6, in which a plurality of discharge tubes 8 are mounted, oriented at an angle with respect to the axis.

The ignition burner 9 extends through the outer wall of the annular channel 6 and the wall of the ignition chamber 2, by which the tangential ignition flame can be generated in the ignition section of the ignition chamber.

A plurality of openings 11 are provided on the wall surface of the distribution pipe 3, and the size of these openings becomes larger toward the combustion chamber 1 direction.

Burner's action is as follows.

A mixture of undifferentiated carbon chamber material (eg lignite or coal) and transport air (eg 10%) is supplied to the distribution chamber 3 via a conduit 5 such that rotational motion is tangentially guided 4. Imparted to the mixture. The mixture subjected to rotational movement along the wall of the distribution chamber 3 gradually flows through the opening 11 into the ignition chamber 2. At the beginning of the distribution chamber a relatively small amount of mixture flows into the distribution chamber through the relatively small opening 11. Therefore, the ignition flame in the ignition burner 9 must be small to raise this small amount of temperature to the ignition temperature. The small amount of powder ignited in this way raises the temperature so that the remaining portion of the mixture supplied into the ignition chamber 2 through the remaining opening is gradually ignited.

Gradually the ignited and well-distributed mixture flows into the combustion chamber 1 and becomes very disturbed by the combustion air supplied through the discharge tube 8. This very disturbing state contributes to good mixing. At high temperatures, short flames are formed. Combustion is substantially complete (at least about 98%). Ignition is simplified due to its gradual nature.

Of importance is a uniform distribution, which is achieved by using a distribution tube 3 in which the opening 11 is formed. In this uniform distribution, a beneficial role is also provided by the rotational movement of the mixture along the wall of the distribution tube.

The surface area occupied by the openings 11 is preferably such that the amount of powder supplied reaches the ignition chamber 2 completely through these openings. In this case, an inhalation effect occurs at the open end of the distribution chamber 3 to introduce flame into the distribution chamber 3, which is beneficial for the temperature of the mixture.

The scope of the present invention also includes having a distribution tube in which the end facing the combustion chamber is closed and rotational motion is not imparted to the mixture of powder and carrier air therein. The distribution tube may also be of a non-cylindrical structure, for example with a venturithroat. The wall of the distribution pipe may be provided with a stiffener. The distribution hole may be in a special form. In addition, the distribution pipe may be in an expanded form up to both ends thereof.

The distribution pipe 3 can be exchanged so that the shape of the opening can be adapted to the situation involved.

The combustion air supplied into the combustion chamber through the channel 6 and the discharge tube 8 may be supplied laterally in a variant in which the channel 6 is produced.

Various other modifications may be made within the scope of the present invention.

However, these modifications are consistent with conditions where a small amount of powder reaches the ignition temperature with air and is ignited and the amount of ignited powder is gradually increased with uniform distribution.

Claims (1)

Delivering a mixture of powdered fuel and compressed carrier air to a combustion chamber, an ignition chamber connected to the combustion chamber, a device for supplying combustion air to the combustion chamber at a location between the ignition chamber and the combustion chamber, a distribution tube in the ignition chamber, and one end of the distribution tube. 12. A burner constructed with a device for discharging, wherein the dispensing device includes a device for imparting a rotational motion to the fuel and air mixture such that the fuel and air mixture flows along the walls of the distribution pipe, the distribution pipe comprising the fuel and air mixture. It has a plurality of openings circumferentially distributed circumferentially along the wall so that it gradually flows outwardly of the distribution tube into the ignition chamber as it flows axially through the tube, and the end of the distribution tube disposed away from the delivery device is the combustion chamber. And the ignition in the ignition chamber flashes the mixture as the fuel and air mixture exits the distribution line through the opening. Burner for pulverized fuel as characterized by the arrangement of the outward pipe to the combustion.

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