JP2004132693A - Oxygen lance for high temperature gasification of waste, and method for operating oxygen lance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combination of a burner and an oxygen lance, and a method for the combination resolving danger and disadvantages of prior art. <P>SOLUTION: The oxygen lance is for high temperature gasification of waste comprising heterogeneous matter thermally treated beforehand when necessary. A channel for transporting reaction oxygen is formed identical to a channel for supplying combustion oxygen into a common channel, and a controller is included for controlling an amount of supplied oxygen in at least two different supplying states. In the method for operating the oxygen lance, the oxygen lance is permanently operated by flame of at least one burner, reactant fuel and oxygen are supplied in stoichiometric composition for the flame of the burner in a first operating mode, and in a second operating mode, oxygen is supplied to the fuel in an excessive stoichiometric composition and this portion of the oxygen enters into a high temperature reactor as a counterpart substance of reaction. <P>COPYRIGHT: (C)2004,JPO

Description

The invention relates to an oxygen spear according to the features of the preamble of claim 1 and to a method for operating the same in a high-temperature reactor.

It is known to achieve a supply of oxygen, for example to a gasification bed in a high-temperature reactor, by means of an oxygen spear to gasify wastes composed of foreign substances. An oxygen spear or lance in the sense of the present invention is usually a water-cooled nozzle through which oxygen or oxygen-enriched air is injected into the internal combustion chamber of a gasification reactor.

German Patent Specification 195 {12 249} C2 has at least a high flame temperature and a high burn rate in such a way that the lance oxygen is accelerated to at least approximately sonic speed, so that the lance oxygen is further heated to very high temperatures It teaches the use of an oxygen spear activated by one permanently burning pilot. This allows hot oxygen to increase the rate of gasification, and the large acceleration of oxygen crucially extends the operating range of the lance.

According to the state of the art, an oxygen spear with a burner for forming a pilot flame is used for this purpose. This combination of burner and oxygen spear ensures that, in addition to the first oxygen channel serving to introduce oxygen to the gasification bed of the reactor, it supplies oxygen to the pilot formed by the burner. The difference is that a separate second oxygen channel is provided.

If the supply of oxygen to the gasification bed of the reactor is stopped and only pilot pilots are activated (burner operation), the partial overpressure in the reactor causes hot syngas to be generated. There is the danger that the reactor will diffuse into the first oxygen channel and no oxygen will be supplied to the oxygen channel. This is because the mixture of hot synthesis gas and oxygen in the first oxygen channel explodes as soon as the oxygen feed is started again to the gasification bed of the reactor for the operation of the burner. Especially dangerous.

If the hot syngas in the burner operation already described diffuses into the first channel for supplying oxygen into the gasification bed of the reactor, the combination of hot syngas and oxygen spear (this , Which is usually cooled by water), has the further disadvantage that the coagulable component of the synthesis gas at least partially coagulates in the first oxygen channel switched off. .
German Patent Specification 195 12 249 C2

It is an object of the present invention to provide a combination of a burner and an oxygen spear and a method of using this combination which can be used in burner operation and which eliminates the above-mentioned risks and disadvantages known from the prior art. That is.

This object is achieved according to the present invention by an oxygen spear according to claim 1 and a method for operating the same according to claim 7.

The present invention has the following advantages in particular.
Due to the fact that the channel for transporting the reactive oxygen, i.e. the oxygen introduced into the gasification bed of the reactor, is identical to the channel for supplying the combustion oxygen, i.e. the burner or the oxygen for supplying the pilot, the burner Irrespective of whether or not the combination of the oxygen spear and the oxygen spear is activated by a pilot flame that is constantly or without oxygen supplied into the gasification bed of the reactor. Since at least the burner flame is supplied with the quantity of oxygen required for stoichiometric combustion (combustion oxygen), it is advantageously achieved that the flow of oxygen is always guided through the oxygen channel. You. In such a process, the hot syngas cannot diffuse from the reactor into the oxygen channels and may explode when the supply of oxygen (reactive oxygen) to the reactor gasification bed is resumed. At the same time as the solidification of the hot synthesis gas in the reaction oxygen supply channel is eliminated.

Furthermore, this arrangement for an oxygen spear device with a burner device, on the one hand, eliminates the need for a connection and an additional channel for a separate inflow of oxygen for the pilot / burner flame, on the other hand. Since the supply of oxygen to the gasification bed of the reactor is not required, the entire system is simplified.

As a result of the fact that a control device is included which controls the amount of oxygen supplied by at least two different air supply conditions, the amount of oxygen required for each is two operating states, namely The supply of reactive oxygen to the burner flame and the gasification bed, and, on the other hand, the burner flame without supply of reactive oxygen into the gasification bed, is sufficient.

In the "burner flame with no reactive oxygen supply to the gasification bed" operating mode, the reactant fuel and oxygen are separated by a near stoichiometric ratio for combustion in the burner flame. Supplied with. In the "burner flame with reactive oxygen supply to the gasification bed" operating mode, in contrast, the oxygen is in excess of the stoichiometric proportion of the supplied oxygen. The part required for combustion in the flame of the burner is supplied to the combustion bed of the high-temperature reactor as a reaction partner.

Fuels throughout the present application can be, for example, methane gas, syngas specific to the process or individual components of the process and liquid and / or pumpable and contaminant-containing materials.

Thus, the pressure of oxygen, especially in the case of the single operation of the burner flame, always exceeds the partial pressure in the high-temperature reactor and effectively prevents the diffusion of hot syngas into the oxygen supply line. To be selected.

Advantageous developments of the invention are possible according to the dependent claims 2 to 6 and 8 to 10, which are subsequently described briefly.
An advantageous embodiment of the control device for controlling the amount of oxygen supplied by at least two different charge states is as a valve connected in parallel in the flow of oxygen. As a result, a technically particularly simple path for creating a robust and required air supply condition is achieved with a precisely adjustable and constantly maintained inflow.

Another development of the invention is that a replaceable burner cap is provided at the reactor end of the burner / oxygen spear combination. This, on the one hand, exposes the burner cap to the hot atmosphere of the hot reactor and therefore has only a limited life as a wear part, and consequently the quick and trouble-free exchangeability of the oxygen spear. Advantageously, maintenance is significantly simplified. On the other hand, the exchangeability of such a burner base is, in particular, due to the savings in the supply channel according to the invention, the burner base sealing the oxygen spear on the reactor side and the connection between the burner base and the oxygen spear. It is particularly preferable due to the characteristic of the present invention that the structure comprising the structure of the connecting portion is extremely simplified. Thus, the burner cap can be formed by a plug-in connection or a screw connection spatially corresponding to the channel of the oxygen spear.

An advantageous development of the method for operating the oxygen spear provides that the control device can switch between the two operating states in a pulsed manner. In this method, the reactive oxygen introduced by an oxygen spear into the gasification bed of the reactor is introduced in a pulsed manner, so that channels in the gasification bed, possibly formed by the flow of oxygen in the lance, are created. The advantage is provided that it is collapsed by a pulsed pause. Thus, "bridge formation" in the gasification bed is avoided.

Subsequently, the present invention will be described with reference to the drawings and embodiments.
FIG. 1 shows a comparison between an oxygen spear for high-temperature gasification of waste composed of foreign substances according to the state of the art (A) and an embodiment (B) of the present invention.

In the state-of-the-art model, three tubular flow channels are formed, one extending concentrically inside the other and currently having a supply pipe connection. In the case of the oxygen spear (A) according to the state of the art, the outermost channel is the channel I for supplying fuel. Inside it is arranged an oxygen supply channel II for actuation of the pilot in the burner, and then a channel III for supplying oxygen as a reactant to the combustion bed of the high-temperature reactor. It is arranged to lie down.

In contrast, in the embodiment B of the present invention, the fuel supply channel I is located inside. A single oxygen channel II surrounds fuel supply channel I, into which separate supply channels for combustion oxygen and reaction oxygen known in the prior art are coupled.

If the burner / oxygen spear combination B is used only in the operation of the burner without oxygen intended to be introduced as a reactant into the combustion bed of the reactor, the fuel channel I and the oxygen channel II each lead as much fuel or oxygen as is required for stoichiometric combustion in the burner pilot, and the oxygen pressure for the burner is reduced by the partial pressure in the high temperature reactor. More than always, the ingress of hot syngas into the oxygenator is selected to be eliminated. Furthermore, if oxygen as reactive oxygen is intended to enter the combustion bed of the reactor, then correspondingly more oxygen is supplied into the oxygen channel II.

This is provided by a control device which is not shown in more detail in this figure.
FIG. 2 shows a longitudinal section of a detailed embodiment of the burner and the oxygen spear according to the invention. Again, a channel I for supplying fuel and a channel II for supplying oxygen are shown, wherein the channel II for supplying oxygen forms a pipe, one located inside the other. So that it surrounds the fuel channel. This is particularly evident in the cross-sectional view along the line AA shown on the right hand bottom.

Furthermore, the connection valve, which is now configured separately from the control valve, and the connection for the flow between the valve and the supply channel are illustrated. Also shown is a water-cooling device comprising a supply pipe connection 11 and flow-through channels 4,5, the water-cooling device being arranged such that along the main axis of the oxygen lance, water is first passed along the entire lance pipe to a burner base. 1 and then out again from the burner base 1 in the opposite direction.

As a result, the burner base 1 is fixed to the lance pipe 2 by a plug-in connection, and has a taper from the reactor side end of the burner base toward the opening of the fuel supply pipe I which is disposed below. It has a funnel-shaped recess attached. Thereby, the burner base is connected such that the cooling water channel moving the water from the side facing away from the reactor towards the burner base flows into the cooling water channel leading the water in the opposite direction. I have. This is caused by the corresponding shape of the burner cap by means of a small channel with walls 31, 32 of the channel forming a hermetic seal with the cooling water channel in the installed state.

FIG. 3 shows a control device according to the invention formed by two valves IV, V connected in parallel to the flow of oxygen and, furthermore, a valve VI for controlling a separate fuel supply. 1 illustrates one embodiment.

Oxygen flows from the stop valve 12 into the left distributor and is split by the distributor into first and second oxygen flows. The flow of the first oxygen flow is controlled by a valve V for combustion oxygen, while the flow of the second oxygen is determined by a valve IV for reaction oxygen. After passing through the valve, the two oxygen streams recombine to form a single stream, which exits the controller. By closing valve IV and the corresponding wide opening of valve V, oxygen is supplied in sufficient quantity for stoichiometric combustion in the pilot of the burner, this pressure being It is necessary to always be above the partial pressure in the high temperature reactor. Therefore, in order to maintain the stoichiometric combustion rate, the opening of the valve VI for controlling the supply of combustion gas must be set accordingly. In addition, oxygen supplied in excess stoichiometric to combustion in the pilot flame, and thus intended to enter as a reactant into the gasification bed of the reactor, may cause valve IV to open. Can be added by The pulsing switching between the first operating mode ("burner only") and the second operating mode ("burner and reactive oxygen supply") is performed in the simplest manner by pulsing the valve IV. This can be done by opening and closing the device.

FIG. 1 shows an oxygen spear (A) for hot gasification of a foreign substance waste according to the prior art and an oxygen spear (B) according to the invention for the same purpose. FIG. 3 shows a longitudinal section and a transverse section of a detailed embodiment of an oxygen spear as an embodiment of the invention with a replaceable burner cap. FIG. 3 shows a control device provided with two valves connected in parallel in the flow of oxygen and also with further valves for supplying combustion gases.

Explanation of reference numerals

1 burner base, 2 lance pipe 4,5 through-flow channel,
11 supply pipe connection, 12 stop valve, 31, 32 channel wall,
I a channel for supplying fuel,
II a channel for supplying oxygen,
III a channel for supplying oxygen,
IV a valve for reactive oxygen,
V valve for combustion oxygen,
VI Valve for controlling the supply of combustion gas

Claims (11)

High-temperature gasification of high-temperature wastes, if necessary, of pre-heated foreign substances having channels (I, II, III) for carrying reactive oxygen, supplying fuel and supplying combustion oxygen. Oxygen spear for
The channel for delivering the reaction oxygen (III) is the same as the channel for supplying the combustion oxygen (II),
An oxygen spear comprising a controller for controlling the amount of oxygen supplied in at least two different supply states. An oxygen spear according to claim 1,
An oxygen spear, characterized in that the control device has valves (IV, V) connected in parallel in the flow of oxygen. An oxygen spear according to claim 1 or 2,
An oxygen spear, characterized in that a replaceable burner base (1) is provided on the reactant discharge side. An oxygen spear according to claim 3,
An oxygen spear, characterized in that the burner cap (1) is fixed by a plug-in connection or a screw connection (31, 32). An oxygen spear according to any one of claims 1 to 4,
Oxygen spear, characterized in that said channels (I, II) extend concentrically in the axial direction with one lying inside the other. An oxygen spear according to any one of claims 1 to 5,
An oxygen spear, further comprising a coolant channel (4,5). A method for operating an oxygen spear according to any one of claims 1 to 6 in a high temperature reactor, comprising:
The oxygen spear is permanently activated by the flame of at least one burner;
In a first mode of operation, reactant fuel and oxygen are provided in substantially stoichiometric proportions for said burner flame;
In a second mode of operation, oxygen is provided in an excess stoichiometric ratio to the fuel such that this percentage of oxygen enters the high temperature reactor as a reaction partner.
The method characterized in that the pressure of oxygen is selected to be always greater than the partial pressure in the high temperature reactor. The method according to claim 7, wherein
The method of claim 1, wherein a pulsed switch occurs between said first mode of operation and said second mode of operation. The method according to claim 7 or 8, wherein
The method wherein methane gas is selected as fuel. The method according to claim 7 or 8, wherein
A process wherein a synthesis gas specific to the process or individual components of the process is selected as fuel. The method according to claim 7 or 8, wherein
A method wherein a liquid and / or a pumpable substance containing pollutants is selected as fuel.

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