JPH022042B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a furnace structure that prevents ash from adhering to a hopper portion constituting the bottom of a boiler furnace.

Coal-fired boilers emit a larger amount of ash than heavy oil-fired boilers, but at the bottom of the furnace, these ash melt due to the high heat inside the furnace and flow downward. FIG. 1 shows an example of a method for removing ash. In the figure, ash is melted by the high heat of the furnace 1, flows down through the hopper section 3, flows into the ash hopper 4, is cooled, and then discharged to the outside. Since this type of boiler allows molten ash (slug) to flow down under its own weight, the hopper section 3 must have a steeply sloping structure in order to properly discharge the ash. Increases weight. However, depending on the nature of the ash, some ash is quite viscous, and in the case of such ash, simply making the hopper part with a steep slope structure is not enough to deal with it, and the ash adhesion may cause the ash hopper 4 to become clogged, or the hopper part to become clogged. This causes problems such as a decrease in the amount of heat received by the water pipes forming part 3.

The object of the present invention is to eliminate the above-mentioned problems and to provide a hopper that can remove ash content well without forming the hopper part with a steep slope.

In short, this invention provides a hopper at the bottom of a furnace having a burner on the side, and the axis of the hopper is parallel to and close to the slope of the hopper, and a part of the combustion exhaust gas sent out from the furnace is recirculated and supplied to the molten slag. The furnace is characterized in that it has ash removal means in which one or more nozzles for ejecting pressurized gas are provided on each of the slopes to promote the discharge of ash.

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

In FIG. 2, a hopper section 3 is formed at the bottom of the boiler body 10. A pressure gas injection nozzle 5 is formed at the connection between the side wall forming the furnace 1 and the hopper part 3, that is, at the upper end of the slope forming the hopper part, and the combustion gas discharged from the boiler body is recirculated as exhaust gas G. The ash is supplied as ash and blown down along the slope of the hopper section 3 to promote the flow of the ash 12 adhering to the slope. The ash flowing down the slope reaches the ash hopper 4 and is cooled. In addition, the code|symbol 2 shows the burner provided in the burner side part. In this embodiment, since recirculated gas is used to prevent ash adhesion, the effect of reducing the concentration of nitrogen oxides (NOx) in the exhaust gas can be expected. Note that it is known to supply recirculated gas into the furnace. Superheated steam temperature control by adjusting heat absorption in the furnace is sometimes very effective at low loads. In addition, the recirculated exhaust gas can be supplied at a constant rate regardless of changes in load.

By carrying out this invention, it is possible to effectively prevent ash from adhering to the hopper, and the hopper inclination angle can be made gentler, making it possible to make the entire boiler compact and lightweight.
It also has the effect of reducing Nox exhaust gas.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hopper section showing a conventional method for preventing ash adhesion, and FIG. 2 is a sectional view of a boiler hopper section for implementing the method according to the present invention. 3... Hotsupa part, 4... Atsushi hopsupa, 10
... Boiler body, 12 ... Ash content (slug), G
...Recirculated exhaust gas, A...High pressure air.

Claims (1)

[Claims] 1 A hopper is provided at the bottom of a furnace having a burner on the side, and a part of the combustion exhaust gas sent out from the furnace is recirculated and supplied with the axis parallel to and close to the slope of the hopper to discharge molten slag. A furnace having ash removal means, characterized in that one or more nozzles for ejecting pressurized gas are provided on each of the slopes.