EP1411296A2 - Oxygen lance for the high-temperature gasification of waste and method of operation - Google Patents

Abstract

An oxygen lance for high temperature gasification of optionally thermally-pretreated waste has channels (I, II and III) for transport of reaction oxygen, introduction of fuel and introduction of oxygen fuel, channel (I) being identical to channel (II) and containing a device which controls the introduced oxygen in at least two flow-through conditions. An Independent claim is also included for operating the lance in a high temperature reactor by operating with a permanent flame and operating firstly with the fuel and oxygen for the flame in approximately stoichiometric ratio and secondly with the oxygen in a super-stoichiometric ratio to the fuel such that a fraction of the oxygen acts as reaction partner in the high temperature reactor, the oxygen pressure always being chosen such that it is higher than the partial pressure in the high temperature reactor.

Description

The invention relates to an oxygen lance according to the Features of the preamble of claim 1 and a method of operating the same in a high temperature reactor.

For the gasification of heterogeneous waste, it is known that Oxygenation to the gasification bed, for example in a high temperature reactor, with the help of oxygen lances to realize. Oxygen lances in the the senses referred to here are water-cooled nozzles, with which usually oxygen or oxygen enriched Air in the internal combustion chamber of gasification reactors is injected.

The German patent 195 12 249 C2 teaches oxygen lances to use with at least one permanently burning pilot flame with high flame temperature and high burning speed operated in this way be that the lance oxygen at least approximately Speed of sound is accelerated whereby the lance oxygen is also extremely heated becomes. The high temperature of the oxygen increases the gasification rate, the strong acceleration of oxygen increases the area of influence the lance is crucial.

According to the state of the art, an oxygen lance is used for this used with a burner for generation the pilot flame is equipped. This burner / oxygen lance combination stands out in particular from the fact that in addition to a first oxygen channel, the for the entry of oxygen in the Gasification bed of the reactor, a separate, second oxygen channel is provided, the supply the pilot flame generated by the burner concerned with oxygen.

Now there is no supply of oxygen into the Gasification bed of the reactor and is exclusively the pilot flame operated (burner operation), so there is the danger of hot syngas from the reactor due to the partial overpressure in the reactor in the first oxygen channel, which is now no oxygen is diffused. This is especially dangerous because of the mixture hot synthesis gas and oxygen in the first oxygen channel can lead to a deflagration as soon as the introduction of oxygen to the burner operation switched back into the gasification bed of the reactor becomes.

Diffuses hot synthesis gas in the previously described Burner operation in the first channel for feeding Oxygen in the gasification bed of the reactor, so there is also the disadvantage that due to the temperature difference between the hot synthesis gas and the one that is usually cooled with water Oxygen lance combination of condensable components of the synthesis gas in the first, turned off Condense the oxygen channel at least partially.

The object of the present invention is to provide a burner / oxygen lance combination as well as a procedure to indicate their use, in burner operation can be used while doing the appraisal the prior art dangers mentioned above and disadvantages.

This object is achieved with an oxygen lance according to claim 1 and a method to operate the same solved according to claim 7.

This solution particularly has the following Advantages on:

Because the channel for transporting reaction oxygen, that is, the oxygen that is required to react Gasification bed of the reactor is introduced, identical is with the channel for supplying fuel oxygen, i.e. the oxygen to supply the burner or pilot flame, is particularly advantageous achieved that regardless of whether the burner / oxygen lance combination with always burning Pilot flame with or without oxygen supply the gasification bed of the reactor is always driven an oxygen flow is led through the oxygen channel is because at least the burner flame with the stoichiometric combustion necessary amount of Oxygen (fuel oxygen) is supplied. To this Way can not hot syngas from the reactor diffuse into the oxygen channel and it will the risk of deflagration when restarting the oxygen supply to the gasification bed of the reactor (Reactive oxygen) avoided and at the same time that Condensation of hot synthesis gas in the reaction oxygen feed channel locked out.

Furthermore, the device-like structure of the oxygen lance simplified overall with burner device, because connections and additional channels for the separate inflow of oxygen for pilot / burner flame on the one hand and the oxygen supply to the gasification bed of the reactor on the other hand.

The fact that a control device is included which is the amount of oxygen supplied in at least controls two different pass states, becomes burner flame for the two operating states and supplying reaction oxygen to the gasification bed on the one hand and burner flame without feed of reaction oxygen in the gasification bed on the other hand the amount of oxygen required in each case dosed fed.

In the "burner flame without Reactive Oxygen Delivery to the Gasification Bed " the reactants fuel and oxygen in approximate stoichiometric ratio for the Combustion fed into the burner flame. In the Operating mode "burner flame with supply of reactive oxygen into the gasification bed " the oxygen in a stoichiometric ratio fed to the fuel so that the portion that over the amount of oxygen supplied to the stoichiometric Relationship to combustion in the burner flame is necessary goes out as a reactant the combustion bed of the high temperature reactor is fed.

Fuel in the sense of this entire application such as methane gas, in-process synthesis gas or individual Components of the same as well as liquid and / or pumpable, pollutant-containing substances his.

By always the pressure of oxygen - especially if the burner flame is operated alone - see above is chosen that it is always greater than the partial pressure in the high temperature reactor, there will be diffusion of hot synthesis gas into the oxygen supply effectively prevented.

Advantageous developments of the invention are in accordance with subclaims 2 to 6 or 8 to 10 possible and are briefly explained below:

An advantageous embodiment for a control device, which is the amount of oxygen supplied in at least two different pass states controls, is the realization as in the oxygen flow valves connected in parallel. hereby becomes a robust and technically particularly simple Path to the establishment of the required forward conditions with precisely adjustable and kept constant Passage reached.

Another development of the invention provides the reactor end of the burner / oxygen lance combination with a replaceable one To provide the burner head. On the one hand, this is advantageous because the burner head of the hot atmosphere the high temperature reactor is exposed and thus as a wearing part only for a limited service life features, so that a quick and easy interchangeability the maintenance of the oxygen lance clearly simplified. On the other hand, the interchangeability of such a burner head especially through the Property of the invention favors that by the saving of supply channels of the invention constructive construction of the oxygen lance on the reactor side final burner head and the connection between burner head and oxygen lance in their structure is significantly simplified. So he can Burner head through a plug or screw connection be realized, which in spatial agreement with the channels of the oxygen lance stands.

An advantageous development of the method for Operating the oxygen lance provides for the control device between the two operating states to switch pulsating. That way that through the oxygen lance into the gasification bed of the reactor entered reaction oxygen pulsating entered so that there is the advantage that channels in the gasification bed which are from the oxygen jet the lance may have been formed in the pulse breaks break down. Thus "bridging" avoided in the gasification bed.

Fig. 1

eine schematische Darstellung einer Sauerstofflanze zur Hochtemperaturvergasung heterogener Abfälle nach dem Stand der Technik (A) sowie einer erfindungsgemäßen Sauerstofflanze zum selben Zweck (B);

Fig. 2

einen Längs- und einen Querschnitt durch eine detailliertere Ausführungsform einer Sauerstofflanze als Ausführungsbeispiel der Erfindung mit auswechselbarem Brennerkopf; sowie

Fig. 3

eine Darstellung einer durch zwei im Sauerstoffstrom parallel geschaltete Ventile implementierten Steuervorrichtung mit einem weiteren Ventil zur Zuführung von Brenngas.

The invention is explained below on the basis of a schematic illustration and an exemplary embodiment. Show it:

Fig. 1

a schematic representation of an oxygen lance for high-temperature gasification of heterogeneous waste according to the prior art (A) and an oxygen lance according to the invention for the same purpose (B);

Fig. 2

a longitudinal and a cross section through a more detailed embodiment of an oxygen lance as an embodiment of the invention with replaceable burner head; such as

Fig. 3

a representation of a control device implemented by two valves connected in parallel in the oxygen flow with a further valve for supplying fuel gas.

Fig. 1 shows a schematic representation of an oxygen lance for high temperature gasification more heterogeneous Waste according to the state of the art (A) and as an exemplary embodiment of the present invention (B) in Juxtaposition.

There are three in the prior art model concentric, tubular Flow channels realized, in the present case with feed pipes are provided. With the oxygen lance according to the prior art (A) is the outermost channel the channel for supplying fuel gas I. Located therein the oxygen supply channel for the Operation of the pilot flame in burner II and again Channel III for feeding is located in it of oxygen as a reactant in the combustion bed of the high temperature reactor.

In contrast, in the exemplary embodiment of the invention B is the fuel supply channel I inside. It surrounds him a single oxygen channel II, to which the separate feed channels known from the prior art for fuel oxygen and reaction oxygen are summarized.

Will the burner / oxygen lance combination B only used in burner operation without oxygen as a reactant in the combustion bed of the reactor should be introduced, so the fuel channel I and the oxygen channel II each so much Fuel or oxygen, as for stoichiometric Burning in the pilot flame of the burner is needed, the pressure of oxygen for the burner is selected so that it is always above the partial pressure in the high temperature reactor, so that hot syngas enters the Oxygenation is excluded. Should be additional Oxygen as reactive oxygen in the Combustion bed of the reactor get, so will more oxygen is supplied in oxygen channel II.

The feed is from that in this figure Control device not shown provided.

Fig. 2 shows a longitudinal section through a more detailed Embodiment of an inventive Burner / oxygen lance combination. Here too the channel for supplying fuel gas I and the channel to supply oxygen II, which is the channel for Fuel surrounds, so that pipes inside each other arise. This becomes particularly clear in the cross section shown along the right Axis A-A.

Furthermore, the connection valves, which are separate here to the control valves and the flow connection between the valves and the feed channels shown. Also shown is the water cooling system, consisting of a supply nozzle 11 and feed-through channels 4 and 5 such that the water along the main axis of the oxygen lance first of all along the lance tube to the tip of the burner 1 inserted and then from the burner tip 1 in the opposite direction.

The burner tip 1 is through a plug connection attached to the lance tube 2 and has a funnel-shaped Sinking on which is from the reactor side End of the burner tip to the lower one Mouth of the feed pipe for fuel I tapered. The burner tip is designed so that the cooling water channel that separates the water from the Spends reactor side facing the burner tip is connected in terms of flow to the cooling water channel, which the water in the opposite direction leads. This is achieved through an appropriate design the burner tip through small, with the cooling water channels tightly fitting when plugged in Channels with channel walls 31, 32.

Fig. 3 shows an embodiment for an inventive Control device, which by two in Valves IV and V connected in parallel with oxygen flow is realized and also a valve VI for control the separate fuel supply.

From the shut-off valve 12, the oxygen flows into the left distributor and divides into a first and a second stream of oxygen. The first flow of oxygen is in its flow rate from the valve controlled for the fuel oxygen V during the second flow of oxygen in its quantity through the valve is determined for the reaction oxygen IV. After passing the valves, they unite two oxygen flows back to a current that then exits the control device. It can by closing valve IV and that accordingly wide openings of the valve V the oxygen in of the amount to be dosed as for stoichiometric Burning in the pilot flame of the burner is required is, this pressure always above the partial pressure must be in the high temperature reactor. to Preservation of the stoichiometric combustion ratio must therefore open the valve VI, which Supply of fuel gas controls, set accordingly become. Additional oxygen, which is related to the Combustion in the pilot flame in superstoichiometric Amount supplied and thus as a reactant in the Gasification bed of the reactor should get through Opening valve IV can be added. The pulsating Switch between the aforementioned first operating mode ("burner only") and the second operating mode ("Burner and reaction oxygen supply") can by pulsating opening and closing of the valve IV can be realized in the simplest way.

Claims (11)

Oxygen lance for high-temperature gasification of possibly thermally pretreated heterogeneous waste, with channels (I, II, III) for the transport of reaction oxygen, for the supply of fuel and for the supply of fuel oxygen,
characterized in that
the channel for the transport of reaction oxygen (III) is identical to the channel for the supply of fuel oxygen (II) and a control device is included which controls the amount of oxygen supplied in at least two different passage states. Oxygen lance according to claim 1, characterized in that the control device has valves (IV, V) connected in parallel in the oxygen flow. Oxygen lance according to one of claims 1 or 2, characterized in that a replaceable burner head (1) is provided on the reactant outlet side. Oxygen lance according to claim 3, characterized in that the burner head (1) is fastened by a plug or screw connection (31, 32). Oxygen lance according to one of claims 1 to 4, characterized in that the channels (I, II) run concentrically one inside the other in the axial direction. Oxygen lance according to one of claims 1 to 5, characterized in that coolant channels (4, 5) are additionally provided. Method for operating an oxygen lance according to one of claims 1 to 6 in a high-temperature reactor,
characterized in that
the oxygen lance is operated permanently with at least one burner flame and in a first operating mode, the reactants fuel and oxygen are supplied in an approximately stoichiometric ratio for the burner flame, in a second operating mode, the oxygen is supplied in a stoichiometric ratio to the fuel, so that this portion of the oxygen reaches the high-temperature reactor as a reactant, whereby the pressure of the oxygen is always chosen so that it is greater than the partial pressure in the high-temperature reactor. A method according to claim 7, characterized in that there is a pulsing switch between the first operating mode and the second operating mode. Method according to one of claims 7 or 8, characterized in that methane gas is selected as fuel. Method according to one of claims 7 or 8, characterized in that process-specific synthesis gas or individual components thereof are selected as fuel. Method according to one of claims 7 or 8, characterized in that liquid and / or pumpable, pollutant-containing substances are also selected as fuel.

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