JPS5848801B2 - bun pie bun - Google Patents

Description

[Detailed description of the invention] This invention relates to a fluidized bed furnace.

Fluidized bed furnaces operate by blowing air and a combustible mixture of O2 through a bed of refractory granular material to maintain the bed in a fluidized state.

The fuel may be solid, liquid or gaseous or a mixture;
Combustion in the bed This maintains the bed at a high temperature, for example in the range of 700 to 1800°C.

Fluidized bed furnaces have very high heat output and good heat transfer properties.

However, difficulties are often encountered when feeding liquid fuels such as fuel oil to fluidized bed furnaces.

This is because the feed nozzles tend to clog and the combustion characteristics are extremely sensitive to fuel distribution.

A distribution plate using a rising membrane for fuel oil described in the applicant's original patent, Japanese Patent No. 1062993 (Japanese Patent Publication No. 56-003484) (hereinafter referred to as the basic specification), has a fuel gas inlet and a fuel oil distribution plate. A chamber including an oil inlet and a number of air pipes passing through the chamber, the interior of the air pipe communicating with the chamber through a hole, and one end of the air pipe terminating within the head. and an outlet device is provided at the head to supply the flammable mixture to the fluidized bed furnace.

Accordingly, the description of the basic specification relates to an apparatus for supplying liquid fuel to a fluidized bed, which fluidized bed is less likely to become clogged than conventional supply apparatuses.

It is desirable to inject (D fuel oil into the fluidized bed with as much flammable air as possible and (Tll fuel oil only) into a fully fluidized bed!

This invention relates to improvements that make more air available for combustion while maintaining the bed in a fluidized state below the fuel injection location.

The present invention provides a distribution plate suitable for use in a fluidized bed furnace, the distribution plate comprising a chamber having a fuel inlet and an air pipe passing through the chamber. the inside of the air tube communicates with the chamber, one end of the air tube terminates in a head having an outlet for supplying a combustible mixture containing fuel and air to the fluidized bed furnace, and a surrounding pipe is provided in the surrounding pipe, and the surrounding pipe is provided with an air inlet button and an air outlet, the air outlet supplying air to a zone of the fluidized bed below the head for supplying the flammable mixture to the fluidized bed. It was designed to do so.

Preferably, a short surrounding tube is connected to the fuel gas supply.

Most preferably, there is another chamber with a fuel gas inlet, which communicates with the surrounding tube.

Before a fluidized bed furnace is used to combust oil, a fuel gas, such as propane, and air are combusted to preheat the bed and begin operation.

Preferably, the distribution plate consists of a number of central air tubes and short surrounding tubes.

Preferably there are 7 to 12 tubes per square foot.

The total cross-sectional area of the outlet of the entire head of the pipe section is 1 of the total area of the distribution plate.
It is preferable to set the diameter to 4φ.

Preferably, the outlet of the outlet forms a passage through the side of the central tube, the direction of this Q passage being substantially perpendicular to the wall of the central tube.

Although the invention is primarily designed for liquid fuels, it can also be used as a distribution plate for solid fuel applications.

In this case, the distribution plate simply functions as an air distribution device.

In order to introduce fuel oil into the fluidized bed, the applicant's original patent, Japanese Patent No. 1062993 (Japanese Patent Publication No. 56-00348)
The rising film technique described in Japanese Patent Publication No. 4) may also be used.

Preferably, the dimensions of the air inlet button and outlet of the outer surrounding tube are suitably selected so that the proportion of air entering the central air tube is between 30 and 70 φ of the total air supplied to the distribution plate.

The bed itself consists of mineral particles having a size range and bulk density appropriate to the velocity of the fluidizing gas.

Suitable materials are crushed refractories, sand, dolomite buttons and limestone.

This distribution plate may also be used for gasification.

That is, it is possible to vary the fuel/air ratio supplied to the bed from substoichiometric conditions to air excess conditions.

Therefore, the distribution plate may be used to produce low Btu fuel gas, which is combusted away from the fluidized bed furnace.

Next, the present invention will be described below with reference to the accompanying drawings.

The fluidized bed furnace has a high pressure chamber, a distribution plate and a mesh size of 1.
0/30 mesh and bulk density 80 per cubic foot
consisting of a fluidized bed of 100 to 100 pounds of sand.

The floor is placed in a 3 foot by 24 foot container lined with refractory material.

This distribution plate consists of a fuel gas chamber 1, an oil chamber 2 and a vertical assembly of two concentric tubes 3, 4.

The inner parts 3 of the two tubes pass through the gas chamber 1 and the oil chamber 2 and have a head 5 adapted to supply the flammable mixture to the fluidized bed furnace.
terminates inside.

A short outer tube 4 passes through the fuel gas chamber 1 and terminates in a head 6 adapted to supply combustion air to the fluidized bed (during start-up of the fluidized bed, the head 6 supplies combustion air and fuel gas). The mixture is fed to the fluidized bed.

The small holes 7 allow the fuel gas to follow from the gas chamber 1 into the air pipe 4).

The air sources for the inner and outer tubes may be common or separate.

Approximately 50% of the fluidizing air passes through the long inner tube creating a rising film of oil, and the remainder enters the gap 8 between the inner tube 3 and the outer tube 4 and emerges from the head 5 to fluidize the bed. .

The head 5 of the inner tube supplies the oil to the fluidized bed and its shape is suitably designed to ensure good distribution and mixing of fuel and air.

The particular design specifications depend on the individual characteristics of the solid to be fluidized and the liquid fuel used.

Fuel oil is supplied to the interior of the inner tube 3, ie to the inner wall of the tube 3, via a flow pedestal device 9 in the form of a length of the tube.

Other suitable flow control devices include weir plates, orifices or perforated wall tubes.

During use of the furnace, the fluidized bed is preheated by a propane-air supply, said propane being supplied from the fuel gas chamber 1.

After the bed reaches suitable operating conditions, the propane feed is tapered and the oil feed feed is started.

The inner tube 3 is controlled by a flow control device 9, e.g. a constant head device.
The oil introduced into the interior of the tube 3 is caused to rise through the tube 3 by the air flow, ie a rising film of oil is formed in the tube.

The oil eventually reaches the outlet hole in the inner tube head 5 where it is consumed in the fluidized bed, accompanied by air.

The total cross-sectional area of the outlet of the pipe head is 1 to 4 of the total area of the distribution plate.
%.

The outlet of the tube head 5 forms a passage through the side of the air tube, the direction of which is substantially perpendicular to the wall of the air tube 3.

The present invention can be summarized as follows.

(1) Consisting of a chamber having a fuel inlet and an air pipe passing through the chamber, the inside of the air pipe communicating with the chamber, and the round end of the air pipe terminating in a head having an outlet. A combustible mixture containing fuel and air is supplied to a fluidized bed furnace, a surrounding pipe is provided around the air pipe, an air inlet and an air outlet are provided in the surrounding pipe, and the air A distribution plate configured to supply air by means of an outlet to a zone of the fluidized bed below the head for supplying the combustible mixture to the fluidized bed.

(The distribution plate according to the above item 1, which connects the surrounding pipe to a fuel gas supply source.

(3) The distribution plate according to item 2, wherein the fuel gas supply source comprises a separate chamber having a fuel gas inlet, and this separate chamber is communicated with the surrounding pipe.

(4) The distribution plate according to any of the above items 1 to 3, which is comprised of a large number of air pipes having surrounding pipes.

(1) The distribution plate according to item 4 above, which prohibits the provision of 7 to 12 air pipes per square foot.

(6) The distribution plate according to any one of the above items, wherein the total cross-sectional area of the outlet of the entire head of the pipe portion is 1 to 4 times the total area of the distribution plate.

(7) Dimensions of the air inlet and outlet of the outer surrounding pipe,
The distribution plate according to any of the above items, wherein the distribution plate is selected so that 30 to 70φ of the total air supplied to the distribution plate passes through the central air pipe.

(8) The outlet according to any of the preceding clauses, wherein the outlet of the head forms a passage passing through the side of the air pipe, and the direction of the passage is substantially perpendicular to the wall of the central pipe. distribution board.

Additional related original patent No. 1 062993, (Special Publication No. 5600348
The invention set forth in claim 1, which can be clicked on in Publication No. 4), comprises a chamber provided with a fuel gas inlet and a fuel oil inlet, and an air pipe penetrating the chamber, A distribution system in which the interior of the tube communicates with the chamber through a hole, one end of the air tube terminating in a head with an outlet, and the main structure is to supply the combustible mixture to the fluidized bed furnace. In contrast, the invention according to the present application includes a chamber having a fuel inlet and an air pipe penetrating the chamber, the inside of the air pipe is communicated with the chamber, and the air pipe is connected to the air pipe. A combustible mixture containing fuel and air is supplied to a fluidized bed furnace, with one end terminating in a head having an outlet, and a surrounding pipe is provided around the air pipe, and an air flow is provided in the surrounding pipe. Relating to a distribution plate provided with an inlet button and an air outlet, said air outlet arranged to supply air to a zone of the fluidized bed below the head for supplying the flammable mixture to the fluidized bed, , the main part of the matter essential to the structure of the invention described in claim 1 of the original patent application is treated as the main part of the matter essential to the structure of the invention, and both are fluidized bed. Since the purpose of this invention is to provide a distribution plate that distributes fuel more uniformly over the entire range of the invention, it falls under the provisions of Article 31, Item 1 of the Patent Law.

[Brief explanation of drawings]

The drawing is a partial vertical cross-sectional view of a distribution plate according to the invention, the cross-section showing a single concentric tube assembly. 1... Gas chamber, 2... Oil chamber, 3... Inner pipe, 4...
...Outer pipe (air pipe), 5...Head, 6...Head,
7... Small hole portion, 8... Gap, 9... Flow rate control device.

Claims (1)

[Claims] 1 A chamber having a fuel inlet and an air pipe passing through the chamber, the inside of the air pipe communicating with the chamber, and introducing liquid fuel onto the inner surface of the air pipe to form a thin film on this surface. a distribution plate for supplying a combustible mixture containing fuel and air to a fluidized bed furnace by terminating one end of the air tube in a head having an outlet; A shorter surrounding tube is provided concentrically around the surrounding tube, and the surrounding tube is provided with an air inlet button and an air outlet, and the air outlet allows air to be supplied to the fluidized bed under the head. A distribution plate configured to feed the side fluidized bed zone.