JPS5912714B2 - Improvements in or relating to coal gasification plants - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coal gasification plant, and more particularly, the present invention relates to a coal gasification plant, and more particularly, the present invention relates to a coal gasification plant, in which coal or other carbonaceous fuel is fed into the top of a cylindrical gasification reactor through tuyeres adjacent to the fuel bed. A type of gasification at high pressure and high temperature using oxygen and water vapor delivered to the
The present invention relates to a burner and quench chamber arrangement for use in a slagged coal gasifier (hereinafter referred to as the type specified in the specification).

Residual ash collects as molten slag and iron in the furnace of the gasification reactor and is periodically discharged from the gasification reactor through a slag tap outlet hole or orifice in the furnace and downwardly into water maintained in a quench chamber. (commonly called slug tapping).

This pool of molten slag and iron is removed from the furnace by regulating the flow path of thermal combustion products from the burner towards the tap orifice, which is typically located below the slag tap orifice to retain the slag and iron above in the furnace. Keep inside.

Reducing the pressure in the quench chamber by stopping or reducing the output of the burner and controlling the exhaust to the atmosphere through the exhaust device to create a pressure difference between the quench chamber and the gasification reactor. to initiate and control tapping of molten slag and iron.

Examples of such slagging gasification plants include British Patent Specification No. 977122, the Ga5Counsil Research Communication
5earch Communication) GC50
and GC112.

Among the shapes of slag tap burners designed for use in such gasifiers are the tangential nozzle mixing type (
tangential nozzle m1xtype
).

That is, the type in which the combustible products are fed separately to the burner and mixed outside the burner to form a stable flame.

The use of this type of burner is problematic in that some of the flame is also directed into the zone above the water in the quench chamber below, causing overheating of the quench chamber walls and other zones above the chamber. Difficulties have been encountered in the upper zone above the water surface.

Another difficulty encountered with such burners is that the combustion products from the burner flow over the water surface before passing through the slag tap holes, allowing the products to cool and thus melt as they pass through the tap holes. The point is that the slag is cooled to produce a solid slag in the tap.

One of the objects of the invention is to provide an improved quench chamber and burner arrangement which is less subject to the above-mentioned disadvantages.

According to the present invention (e), in a method of operating a coal slagging gasifier of the type specified in the above specification, which comprises a burner in a quenching chamber in contact with the bottom surface of a slag discharge orifice, A secondary feed of combustion sustaining gas containing at least a portion of the required oxygen is provided above the water surface in the chamber and at a distance from the burner so that the flow path of the combustion sustaining gas is connected to the tap. A slag of the combustion sustaining gas is also configured to flow through the space within the quenching chamber between the water surface and to form a layer of gas interposed between the chamber wall and the combustion products from the burner. A method of operating a coal slagging gasifier as described above is provided, characterized in that the upward flow towards the tap orifice regulates the downward flow of combustion products from the burner and cools the quench chamber wall. Ru.

It is an advantage that the burner can be operated with combustion sustaining gas supplied remotely from the burner.

In this case, it is preferred that the combustion sustaining gas contains 10-90% of the oxygen required for combustion in the burner.

The burner can be operated with the combustion sustaining gas being a mixture of carbon dioxide and oxygen or air, and with the gas being supplied at about room temperature.

A device for performing the operation comprises a burner in contact with the bottom surface of the slag discharge orifice in the quench chamber;
A device for supplying the combustion sustaining gas to the burner in a flow path flowing through the space within the chamber is preferably included.

However, the latter shall be located within the chamber above the water surface and away from the burner.

It is an advantage that the combustion sustaining gas flows over the entire length of the space between the water surface and the slug tap, so that the combustion sustaining gas is in contact with the vessel wall of the chamber and has a positional force ζ just above the water surface. It is preferable to supply from

Preferably, the combustion sustaining gas is supplied from a supply device consisting of a mounting ring with a number of outlet holes equidistantly spaced along the surface.

Further, it is preferable that the mounting ring is located in the chamber in contact with the vessel wall and above the water surface.

During the slag tapping operation, the ring must not be contaminated by falling slag, and it is therefore preferable to shield the ring from falling slag during the tapping operation when operating with the gasifier.

Preferably, the burner is of the ring nozzle mixing type.

It is also preferred that the burner consists of separate chambers for the fuel gas and primary air supply, each chamber having at least one inlet and a number of outlet holes arranged along the inner circumference of the ring.

Furthermore, the inner periphery of the ring burner has an inclined wall through which the outlet hole is formed so that the fuel gas and the primary air supply converge in the space defined by the ring. Preferably, the arrangement is such that there is an air flow.

In order that the invention may be more clearly understood, one embodiment of the invention will be described with reference to the accompanying schematic drawings, which are merely examples.

Referring first to FIG. 1, the gasifier has a refractory-lined pressurized gasification chamber 1 into which coal is fed from the top.

Oxygen and water vapor are introduced into the chamber 1 through the tuyeres 2 to promote gasification of the coal.

In use of the present gasifier, a pool of molten slag collects in a tilting furnace 3 and is periodically pumped through a slag tap 4 into a sump 5 maintained in a quench chamber 6.

,@, The molten slag is rapidly cooled in the cold chamber 6 and sent to a lock hopper (not shown) in the form of a finely ground frit.

This quench chamber 6 is connected to the bottom end of the gasification chamber 1 with a spacer member or sandwich flange 7 in between.

Further, referring to FIGS. 2 and 5, a metal tube 8 is fixed upward from the flange 7,
At its upper end it is fixed to an annular metal block 9, which supports a ring-shaped burner 10 located below and concentrically with the slug tap 4.

The burner is of the nozzle mixing ring type (described in detail below) and includes a gas ring 11 with gas outlet holes 12 and an air ring 13 with air outlet holes 14.
It is preferable to consist of.

The burner is supported by a metal ring 19 including a flange 20.

This flange 20 (and thus the ring 19) is removably fixed to the metal block 9 by means of bolts 21.

In use of the present gasifier, a secondary combustion sustaining gas or gas mixture is supplied to the burner 10 from a mounting ring 15 having outlet holes 16 located at any suitable equidistant intervals along the mounting ring.

These gas flow paths flow upward toward the burner 10, forming a flow path as shown in FIG.

This gas or gas mixture flows through the upper part of the quench chamber 17 and through the zone 18 .

Zone 18 is a zone defined by sand inch flange 7 and metal tube 8 .

In conventional gasifiers, a portion of the combustion products from the slag tap burner flows down into zones 17 and 18;
The problem was that the vessel walls surrounding these zones were overheated.

A portion of the combustion products from this burner flows downward into the third
It is shown in the figure.

According to the invention, the upward flow of gases and gas mixtures from the mounting ring 15 restricts the downward flow of combustion products from the burner, so that heating of the vessel walls around zones 17 and 18 is considerably avoided. be done.

Furthermore, the gas flow from the mounting ring 15 has a cooling effect on these vessel walls.

A preferred arrangement of the slag tap burner 10 described above is shown in FIG.

This is an annular gas and air passage 23 arranged above and below.
and 24, the passage 2
3 and 24 are supplied with gas and air via inlets 25 and 26, respectively.

The inner annular sloped wall 28 of the burner structure 22 has a number of spaced apart gas and air outlet holes 12 and 14 in two rows, one above the other, each row having a respective gas or air passageway 23. 24.

During the slug tapping operation, the slag falls through the slug tap orifice 27 and passes through the center of the burner 10.

In the past, the problem was that this slag fouled and damaged the burner.

In the preferred ring burner described above having the sloped surface 28 out of the path of the molten slag, fouling of the burner does not occur.

Another advantage of the present invention is that the burners can be installed to operate in an independent manner, or in other words, can be operated from gas-rich mixture conditions to oxygen-rich mixture conditions.

When the burner is operated with an oxygen-deficient gas mixture, carbon formation occurs, which means that the flame forms a carbon layer on the bottom of the slag tap, forming a protective coating, which covers the bottom surface formed during the gasification process. It is useful in that it prevents attacks from iron.

Yet another advantage of this device is that when the burner is in an oxygen-rich condition, this excess oxygen reacts with the carbon dissolved in the slag to create an exothermic reaction, thereby reducing the amount of melted products in the furnace. This is due to an increase in temperature.

It is clear that this increases the reactivity of the reactants in the gasification process.

Another advantage of this device is that when the burner flame is reduced before the slag tapping operation, the primary air supplied through the air outlet hole 14 is reduced to the limit necessary to maintain combustion in the burner 10. It is preferable that the oxygen is supplied by the secondary combustion sustaining gas ring 15.

This is preferred because supplying air to the burner from the primary air supply causes excessive thrust up through the slag orifice, resulting in dispersion of the slag flow during the slug tapping operation.

If oxygen is supplied from the secondary gas supply ring 15, this dispersion can be greatly reduced.

Yet another advantage of the device is that in burners supplied with oxygen by primary and secondary supply devices, the flame from the burner is more stable and has a more stable appearance.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a portion of the slagging gasifier. FIG. 2 is an enlarged longitudinal sectional view of the upper zone of the quench chamber. 3 and 4 are schematic diagrams showing the flow pattern of gas circulating in the upper part of the quench chamber. FIG. 5 is a side sectional view of the burner.

Claims (1)

[Claims] 1. A burner is provided in the quenching chamber adjacent to the bottom of the slag discharge orifice, and coal or other carbonaceous fuel is delivered to the top of the cylindrical gasification reactor and passed through the slag near the fuel bed. In a method of operating a coal slagging gasifier of the type that gasifies at high pressure and high temperature using oxygen and water vapor supplied, combustion sustaining gas containing at least a portion of the oxygen necessary for combustion in the burner is heated to the water surface in a quenching chamber. By supplying the combustion sustaining gas secondarily from a position located above and away from the burner, the flow path of the combustion sustaining gas flows in the space within the quenching chamber between the slag tap and the water surface, and an intervening gas layer between the vessel wall and the combustion products from the burner, and the upward flow of the combustion sustaining gas toward the slag tap orifice suppresses the downward flow of combustion products from the burner. A method of operating the coal slagging gasification apparatus, characterized in that the method comprises controlling the temperature and cooling the wall of the quench chamber. 2. The method of claim 1, wherein the combustion sustaining gas contains 10-90% of the oxygen required for combustion in the burner. 3. The method according to claim 1, wherein the combustion sustaining gas is a mixture of carbon dioxide and oxygen. 4. The method according to claim 1, wherein the combustion sustaining gas is air. 5. The method according to claim 1, characterized in that the combustion sustaining gas is supplied from a position in contact with the wall of the quenching chamber and immediately above the water surface within the chamber. 6. The method according to claim 1, characterized in that the combustion sustaining gas is supplied at approximately room temperature. 7. A cylindrical reactor and a device for feeding coal or other carbonaceous fuel to the top of the reactor and introducing oxygen and water vapor into the reactor for gasifying the fuel within the reactor. a furnace for collecting the molten slag and iron produced during the gasification of said combustion, provided that said furnace has a slag tap orifice for periodically discharging the slag downwardly; a quench chamber located below the slag tap orifice for quenching slag discharged through the slag tap orifice, provided that the quench chamber is constructed and constructed to retain a quench liquid therein; a burner located within the quench chamber to regulate the flow of hot combustion products adjacent to the bottom of the slag tap orifice to retain the slag and iron in the furnace; Coal slag with a device for stopping or reducing the output and for starting tapping of the molten slag consisting of a device for reducing the pressure in the quenching chamber with respect to the pressure in the gasification reactor In a converter-gasifier, a secondary supply of combustion sustaining gas containing at least a portion of the oxygen required for combustion in the burner in the quench chamber is provided above the level of the quench liquid held in the quench chamber. A coal slagging and gasifying apparatus as described above, further comprising a device for feeding from a position within the quench chamber remote from the burner in the quench chamber. 8. Device according to claim 7, characterized in that the feeding device is in the form of a tubular ring with a number of outlet holes located equidistantly along the surface. 9. The device according to claim 7, wherein the supply device is disposed at the bottom of the chamber space, just above the water surface in the chamber and in contact with the wall of the chamber. 10 Claim 9, characterized in that the tubular ring is arranged so as to be shielded from falling slag.
Apparatus described in section. 11. Apparatus according to claim 8, characterized in that the burner is a nozzle mixing ring type burner. 12 The burner is characterized in that it consists of separate chambers for the fuel gas and the primary air supply, each chamber having at least one inlet and a number of outlet holes arranged along the inner circumference of the ring. An apparatus according to claim 11. 13 The inner periphery of the ring forms an inclined wall through which the outlet hole is formed and in use a fuel air stream consisting of fuel gas and a primary air supply in the space defined by the ring. 12. Apparatus according to claim 11, characterized in that it is arranged to supply. 14 The combustion sustaining gas supply device is located above the water surface in the chamber and at a distance from the burner, the supply device being made of a tube with a number of equally spaced outlet holes along its surface. is in the form of a ring, and the burner is a nozzle mixing ring type burner consisting of an annular structure having separate fuel gas annular chambers and primary air annular chambers, each of which has fuel gas and primary air into its chambers respectively. a plurality of outlet holes arranged in the inner circumferential wall of the burner structure and communicating with respective passages, through which the fuel gas flow and the primary air flow pass. Claim 7, wherein the mixture is mixed in the center of the space defined by the annular structure, and the inner wall slopes downward and outward from the top of the structure. equipment.