KR20040034444A - Oxygen lance for high temperature gasification of wastes, and also method for operating the same - Google Patents

Abstract

PURPOSE: An oxygen lens and an operating method thereof are provided to effectively prevent the diffusion of hot synthetic gas into an oxygen supply line by selecting the oxygen pressure over a partial pressure inside a high temperature reactor when operating only by burner flames. CONSTITUTION: A channel for carrying reaction oxygen is same as a channel for supplying combustion gas(II). A controller controls the supplied oxygen amount in a different inflow status. The controller contains valves to be connected with an oxygen flow in parallel. A changeable burner tip(1) is installed in the side of a reactant outlet. The burner tip is fixed by a plug-in or screw connections(31,32). Channels(I,II) are extended concentrically while locating one channel inside the other channel. Coolant channels(4,5) are installed additionally. Thereby, the diffusion of hot synthetic gas into the oxygen channel is prevented. Moreover, the explosion when the oxygen supply is restarted into a gasification layer of a reactor and the condensation of the hot synthetic gas inside the reaction oxygen supply channel are prevented.

Description

OXYGEN LANCE FOR HIGH TEMPERATURE GASIFICATION OF WASTES, AND ALSO METHOD FOR OPERATING THE SAME}

The present invention provides an oxygen lance for gasifying a non-uniform waste thermally pretreated as needed, having a reactive oxygen transport channel, a fuel supply channel, and a combustion oxygen supply channel (I, II, III); And a method for its operation in a high temperature reactor.

In order to gasify non-uniform wastes, it is known to supply oxygen by means of an oxygen lance, for example to a gasification layer in a high temperature reactor. Oxygen lance herein refers to a nozzle that is cooled by water, whereby oxygen or oxygen enriched air is generally injected into the internal combustion chamber of the gasification reactor.

German patent specification No. 195 12 249 C2 uses one or more permanently combusted pilot flames of high flame temperature and high combustion rate, so that the oxygen of the lance is accelerated at a speed at least close to the speed of sound, which is very high temperature. The use of oxygen lances that are operated in such a way as to be heated to higher temperatures is described. This allows high temperature oxygen to increase the gasification rate, and the high acceleration of oxygen decisively increases the operating range of the lance.

According to the prior art, an oxygen lance equipped with a burner for generating a pilot flame is used for this purpose. Such a combination of burner / oxygen lances can be provided with a second, separate oxygen channel, in particular in addition to the first oxygen channel for introducing oxygen into the gasification layer of the reactor, so that the oxygen of the pilot flame produced by the burner can be provided. There is a feature in.

When the oxygen supply into the gasification layer of the reactor is stopped and only the pilot flame is activated (burner operation), the hot syngas flows into the first oxygen channel where virtually no oxygen is supplied from the reactor due to the partial ultrahigh pressure in the reactor. There is a danger of spreading. This phenomenon is particularly dangerous because as soon as the oxygen supply into the gasification layer of the reactor for operating the burner is switched again, the mixture of hot synthesis gas and oxygen in the first oxygen channel can cause an explosion.

In the burner operation described above, when the hot syngas diffuses into the first channel for supplying oxygen into the gasification layer of the reactor, it is also generally due to the temperature difference between the combination of the hot syngas and the oxygen lance cooled with water. A substantial component of the syngas is at least partially condensed in the first oxygen channel being switched off.

An object of the present invention is a combination of a burner / oxygen lance; And burner operation which relates to their use in order to cope with the above mentioned risks and disadvantages with the knowledge of the prior art.

This problem is characterized in that the reactive oxygen transport channel (III) is identical to the combustion oxygen supply channel (II), and a control device for controlling the amount of oxygen supplied in at least two different inflow states is included. An oxygen lance having a fuel supply channel and a combustion oxygen supply channel (I, II, III), for gasifying the thermally pretreated non-uniform waste at high temperature as needed; And the oxygen lance is permanently operated with at least one burner flame, in which the reactant fuel and oxygen are supplied in a ratio close to the stoichiometric ratio with respect to the burner flame in the first operating mode, and in the second operating mode, oxygen is superchemical Supplied in a stoichiometric ratio such that an amount of oxygen is introduced into the high temperature reactor as a reaction partner, and the oxygen pressure is selected such that it is always selected to exceed the partial pressure in the high temperature reactor of the oxygen lance in the high temperature reactor. It is achieved according to the invention by the method of operation.

This solution has the following advantages in particular:

In the case where the reactive oxygen transport channel, i.e. oxygen introduced into the gasification layer of the reactor for the purpose of reaction, is the same as the combustion oxygen supply channel, i.e. oxygen for supplying the burner or pilot flame, the present invention provides oxygen to the gasification layer of the reactor Regardless of whether the burner / oxygen lance combination is operated using a constant flame, even if not supplied, at least the burner frame is supplied with a certain amount of oxygen (combustion oxygen) required for stoichiometric combustion. This is achieved in a particularly advantageous manner in which oxygen flow is always introduced through the oxygen channel. In this way, hot syngas cannot diffuse from the reactor into the oxygen channel, while the risk of explosion is avoided when the oxygen (reactive oxygen) supply to the gasification layer of the reactor is restarted, while at the same time within the reactive oxygen supply channel Condensation of the hot synthesis gas is excluded.

In addition, the oxygen supply to the gasification layer of the reactor as well as the connections and additional channels for the separate oxygen inlet flow to the pilot / burner flame is not necessary, which simplifies the overall configuration for the oxygen lance device with burner devices.

The amount of oxygen required, respectively, from the fact that a control device for controlling the amount of oxygen supplied in two or more different inflow states is included; A burner frame when reactive oxygen is supplied into the gasification layer; And a burner flame when no reactive oxygen is supplied into the gasification layer.

In the operating mode of "burner flame when no reactive oxygen is supplied into the gasification layer", the reactant fuel and oxygen are supplied at an appropriate stoichiometric ratio for combustion in the burner flame. In the operating mode of "burner flame when reactive oxygen is supplied into the gasification layer", in contrast, oxygen is supplied in the "hystostoichiometric ratio" to the fuel, so that the burner flame exceeds the amount of oxygen supplied in the stoichiometric ratio. The amount necessary for combustion in the furnace is supplied as a reaction partner for the combustion bed of the high temperature reactor.

In the context of this overall use the fuel can be, for example, methane gas, syngas specific to the same individual component or process, and liquid and / or pumpable contaminant-containing materials.

This effectively prevents the diffusion of the high temperature synthesis gas into the oxygen supply line, in particular in that the oxygen pressure is always chosen to exceed the partial pressure in the high temperature reactor when operating only with the burner flame.

Advantageous improvements of the invention are made possible according to the dependent claims 2 to 6 or 8 to 10, which are briefly described below.

1 is a schematic diagram showing an oxygen lance A according to the prior art for gasifying non-uniform waste at high temperatures, and an oxygen lance B according to the invention for the same purpose.

FIG. 2 shows a longitudinal section and a cross section of a detailed embodiment of an oxygen lance as an embodiment of the invention with an exchangeable burner tip. FIG.

FIG. 3 shows a control device carried out by two valves connected side by side to an oxygen flow, with an additional valve for supplying combustion gas.

An advantageous embodiment for a control device that controls the amount of oxygen supplied at two or more different inlet states is to be used as a valve connected side by side with the oxygen flow. As a result, a reliable and technically particularly simple method for forming the required inflow state is achieved with a precisely adjustable and constant inflow rate.

Another improvement of the present invention is that an exchangeable burner tip is installed at the reactor-side end of the burner / oxygen lance combination. This means, on the one hand, that the burner tip is subjected to the high temperature atmosphere of the high temperature reactor so that the burner tip has only a limited life as a wearing part, so that rapid and trouble-free exchangeability greatly reduces maintenance of the oxygen lance. This is beneficial because it simplifies. On the other hand, the exchangeability of such burner tips is due in particular to the savings of the feed channel according to the invention, and also to the structure of the burner tip which seals the burner tip and the connection between the oxygen lance and the oxygen lance on the reaction side. Is supported by the features of the present invention that greatly simplifies its configuration itself. Thus, the burner tip may be formed by a plug-in or screw connection that spatially corresponds to the channel of the oxygen lance.

An advantageous improvement to the method of operating the oxygen lance is that the control device can be switched over in a manner that is pulsed between two operating states. In this manner, the reactive oxygen introduced into the gasification layer of the reactor by the oxygen lance is introduced in the pulsed state, providing the advantage that the channels in the gasification layer that could have been formed by the oxygen beam of the lance collapse in the pulsed state. . Thus, "bridge forming" is prevented in the gasification layer.

The invention is illustrated below by means of schematic drawings and embodiments:

1 is an oxygen lance A according to the prior art for gasifying non-uniform waste at high temperature; And a schematic view showing an oxygen lance (B) as a specific example of the present invention as a comparative example.

In the case of a model according to the prior art, three tubular flow channels which are concentrically extending one inside other are produced, which are currently connected to the supply pipe connection. Is installed. In the case of the oxygen lance A according to the prior art, the outermost channel is the fuel supply channel I. An oxygen supply channel (II) for operating the pilot flame in the burner is located therein, and an oxygen supply channel (III) as a reactant is located therein in order in the combustion bed of the high temperature reactor.

In contrast, in embodiment (B) of the present invention, the fuel supply channel (I) is located inside. A single oxygen supply channel (II) surrounds the fuel supply channel, which is a combination of separate supply channels for combustion oxygen and reactive oxygen, which are known in the art.

When the combination (B) of the burner / oxygen lance is used only for burner operation without introducing oxygen as reactant into the combustion bed of the reactor, the fuel supply channel (I) and oxygen supply channel (II) are each pilots of the burner. This is accomplished by using as much fuel or oxygen as is required for stoichiometric combustion in the flame, the pressure of the oxygen on the burner being such that it always exceeds the partial pressure in the high temperature reactor, thereby increasing the temperature of the hot syngas into the oxygen source. It is chosen in such a way that penetration is excluded. In addition, if oxygen as reactive oxygen is to be introduced into the combustion bed of the reactor, a correspondingly larger amount of oxygen is fed to the oxygen supply channel (II).

As such, the supply is provided by a control device that is not shown in more detail in the figure.

Figure 2 shows a longitudinal section of a detailed embodiment of the burner / oxygen lance combination according to the invention. Also shown here is the channel I for supplying fuel and the channel II for supplying oxygen, which encloses such a channel for fuel and consequently forms a pipe in the form of one located inside the other. This point is particularly evident from the cross section along axis A-A indicated on the right bottom.

Also shown are control valves, which are currently individually configured from control valves and connections to the flow between these valves and the supply channels. Cooling by water comprising a feed pipe connection 11 and through flow channels 4, 5 also follows the main axis of the oxygen lance, after which the water is first introduced along the entire lance pipe to the burner tip 1. It is shown in such a way that it again exits in the opposite direction from the burner tip 1.

The burner tip 1 is thus fixed to the lance pipe 2 by a plug-in connection, which has a taper funnel towards the opening of the fuel supply pipe I located downward from the reactor-side end of the burner tip. A recess of the form is provided. The burner tip is thus configured such that the channel for cooling water, from which the water enters from the side oriented from the reactor towards the burner tip, is connected in a flow direction with respect to the channel for cooling water where water is introduced in the opposite direction. This is caused by the corresponding configuration of the burner tip by means of a small channel with channel walls 31, 32, which, when mounted, form an airtight seal with the channel for cooling water.

FIG. 3 shows an embodiment of the control device according to the invention, which is formed by two valves IV, V connected side by side with respect to the oxygen flow, and a valve VI for controlling a fuel supply separated therefrom.

From the stop valve 12, oxygen flows to the right distributor and splits into first and second oxygen flows. The first oxygen flow is controlled by the amount of through flow by the valve for combustion oxygen V, while the second oxygen flow is determined by its amount by the valve IV for reactive oxygen. As they pass through the valves, the two oxygen flows to recombine to form one flow and then exit the control device. By closing the opening of valve (IV) and correspondingly wide valve (V), an amount of oxygen can be administered in an amount as required for stoichiometric combustion in the burner's pilot flame, which pressure is always in the high temperature reactor. Required to exceed the partial pressure at. Therefore, in order to maintain the stoichiometric combustion ratio, the opening of the valve VI controlling the supply of the combustion gas must be set accordingly. Additional oxygen, which is supplied in a stoichiometric amount for combustion in the pilot flame and is intended to be treated as a reactant into the gasification layer of the reactor, can be added by opening valve IV. The pulsed switching between the above-mentioned first mode of operation (only performed with burner only) and second mode of operation (performed with burner and reactive oxygen source) allows the pulsed opening and closing of the valve IV in the most simplified manner. Can be generated by

With the present invention, the hot synthesis gas cannot diffuse from the reactor into the oxygen channel and the explosion risk is avoided when the oxygen supply to the gasification layer of the reactor is restarted, while at the same time condensation of the hot synthesis gas in the reactive oxygen supply channel This excluded advantage is obtained.

Claims (11)

An oxygen lance for reacting a non-uniform waste thermally pretreated as needed at high temperature with a reactive oxygen transport channel, a fuel supply channel and a combustion oxygen supply channel (I, II, III), Oxygen lance, characterized in that the reactive oxygen transport channel (III) is identical to the combustion oxygen supply channel (II), and a control device for controlling the amount of oxygen supplied in at least two different inflow states. 2. Oxygen lance according to claim 1, characterized in that the control device has valves (IV, V) connected side by side to the oxygen flow. 3. Oxygen lance according to claim 1 or 2, characterized in that an exchangeable burner tip (1) is installed on the side of the reactant outlet. 4. Oxygen lance according to claim 3, characterized in that the burner tip (1) is secured by a plug-in or screw connection (31, 32). 5. Oxygen lance according to any of the preceding claims, characterized in that the channels (I, II) extend concentrically in the axial direction in such a way that one is located inside the other. . 6. Oxygen lance according to any one of the preceding claims, characterized in that the coolant channels (4, 5) are additionally provided. A method of operating an oxygen lance according to any one of claims 1 to 6 in a high temperature reactor, The oxygen lance is permanently operated with one or more burner flames, In the first mode of operation, the reactant fuel and oxygen are supplied at a ratio close to the stoichiometric ratio to the burner flame, and in the second mode of operation, oxygen is supplied at the hyperstoichiometric ratio of the fuel such that this amount of oxygen is the high temperature as the reaction partner. Introduced into the reactor, The oxygen pressure is chosen such that it always exceeds the partial pressure in the high temperature reactor. 8. The method of claim 7, wherein a pulsed switch-over occurs between the first mode of operation and the second mode of operation. 9. A process according to claim 7 or 8 wherein methane gas is selected as fuel. The method according to claim 7 or 8, characterized in that the synthesis gas specific for the same individual component or process is selected as the fuel. 9. A method according to claim 7 or 8, characterized in that the liquid and / or pumpable contaminant containing material is selected as the fuel.