EP0922773A1 - Method and device for pneumatic conveyance and blowing of bulk material in a metallurgical melting furnace - Google Patents

Abstract

The material is mecanically extracted from the bottom end (2b) of the pressure vessel (2) and fed into the conveying pipeline (9). The melting reactor (1), pipeline (9), unit (8) and pressure vessel (2) are connected to one another and form an open pressure system. Automatic pressure equalization takes place at least between the top end (2a) and the material entry chamber (12) into the pipeline (9).

Description

The invention relates to a method and a System for the pneumatic conveying and blowing of bulk material that is difficult to flow and tends to solidify, especially of essentially granular plastic material, Secondary material or the like, in at least one metallurgical smelting reactor, accordingly according to the preamble of claim 1 or the generic term of claim 8.

It is already known that hydrocarbon Waste plastics, secondary recyclables or the like in metallurgical smelting reactors introduced and there especially as a reducing agent for metallurgical Melting can be used, i.e. from collections originating plastics and secondary recyclables not just burned in this way, but them can be used as chemical reducing agents in metallic Melting can be used and thereby part of the otherwise necessary reduction coal and others for reduction replace the hydrocarbons used. This However, old plastics, secondary recyclables, etc. must previously in a pneumatically conveyable and in melt reactors inflatable bulk at least sufficient crushed and / or processed in a corresponding manner become.

Accordingly, it is known from EP-A-622 465 Waste plastic in shredded, fluidized form pneumatic to the nozzles or wind forms of a metallurgical To promote shaft furnace (blast furnace) and there distributed blowing, in a similar way as other reducing agents, e.g. Coal dust or oil. Suitable waste plastics (e.g. packaging cups, Plastic films and the like). In this known version these substances are supposed to be crushed, shredded and / or thermal processing to a particle size from about 1 to 10 mm, in particular about 5 mm, processed and then introduced into an injection or pressure vessel become. This is prepared in this pressure vessel Bulk plastic by blowing one Fluidizing gas (by means of a blower and over Lines) fluidized, discharged at the lower end and a separate metering device, e.g. a mechanical one Screw dosing device, supplied from where dosed into a pneumatic conveyor pipe fed in and blowing points in the form of lances is required, via which it is gassed in the Blast furnace is blown in, the prevailing in the blast furnace Back pressure must be overcome.

To the in this known version (EP-A-622 465) Sufficient plastic material in the injection vessel (pressure vessel) To be able to fluidize this material in are sufficiently fine-grained or powdery, which means a correspondingly high size reduction or Not to mention processing costs that the injection vessel with appropriate Fluidizing devices must be equipped.

The invention is based on the object of a method according to the preamble of claim 1 and a system according to the preamble of the claim 8 in such a way that with reliable dosing of the bulk material as well as with a relatively small construction Effort also relatively coarse Bulk goods of various types reliably pneumatic conveyed and into a metallurgical smelting reactor can be blown.

On the one hand, this task (procedural) by the characterizing features of claim 1 and on the other hand (system engineering) through the labeling features of claim 8 solved.

Advantageous refinements and developments of Invention are the subject of the dependent claims.

According to the method according to the invention, the bulk material, in particular plastic material, secondary recyclable material or the like, initially in essentially fine to coarse-grained condition using a combined discharge and metering device mechanically the lower end or lower part of the pressure vessel conveyed out and dosed into the pneumatic conveying pipeline fed. Here, melting reactor, Delivery pipeline, discharge and dosing element as well Pressure vessel with the formation of an open pressure system connected with each other. And at least between the upper end or upper part of the pressure vessel and the good feed point into the conveyor pipeline automatic pressure compensation established.

Compared to the known one described above Process (EP-A-622 465) is in the inventive Process aware of fluidization of the bulk material dispensed in the pressure vessel, which is a clear one Structural simplification of the pressure vessel (including without Fluidization devices) and the other advantage brings with it that also relatively coarse-grained Bulk materials are metered reliably and conveyed pneumatically can be. The latter is mainly due to the use of the combined discharge and dosing device, that the fine to coarse-grained bulk material, i.e. Bulk material with a relatively large grain spectrum, continuous mechanically conveyed out of the pressure vessel or discharges and accordingly in the pneumatic Feeding pipeline. This combined discharge and dosing device thus works within the Pressure vessel in the full bulk so that it is this Bulk material loosens in an advantageous manner and thereby a risk of constipation, for example through Bridging, effectively countered. This favors thus also the discharge and dosing of poorly flowing and relatively coarse-grained, which tends to solidify Material such as appropriately shredded or processed Plastic material from waste plastics, e.g. from packaging and film materials, as well as secondary materials or similar. This handling of relative coarse-grained material has the further advantage with the fact that crushing, shredding, agglomeration or other processing with a - compared to the known method described above - relative low system and process costs are operated can.

In this method according to the invention also form Melting reactor, production pipeline, discharge and Dosing device and pressure vessel an open pressure system, and this is at least between the top of the Pressure vessel and the feed point into the delivery pipeline automatic pressure compensation is established. This can be the pressure vessel and the feed point the delivery pipeline by an appropriate Pressure equalization line to be connected. Can within the mentioned open printing system equalize pressures unhindered by gas flows in all directions depending on the current Pressure ratios are allowed. The bulk material inside the pressure vessel allows at least because of it partial coarseness and the associated high gas permeability of the bulk material an unimpeded gas exchange within the actual Blowing apparatus with pressure vessel, discharge and Dosing device and pneumatic delivery pipeline. Of the Conveying pressure for pneumatic conveying arises automatically to the required pressure level on. A separate regulation of the overpressure in the upper Part of the pressure vessel and the pressure difference between Pressure vessel and delivery pipeline - as with known ones Versions - omitted in the invention. At this Execution according to the invention thus arises in the the blowing apparatus mentioned at any time from the reactor counterpressure and pressure losses due to conveyor technology (Friction, acceleration, etc.) resulting delivery pressure on. The delivery rate in this invention Process depends only on the mode of operation, especially the speed of the combined used here Discharge and dosing device from and not - how in the known versions - from the top pressure of the Pressure vessel.

According to the invention, the corresponding bulk material can also be used a grain or piece size of up to about 25 mm conveyed and blown into the melting reactor.

In a further embodiment of the invention, this can Bulk at least partially in the form of agglomerates or pellet processed plastic material used and as a reducing agent in a molten metal be blown in.

What is to be pumped and blown into a smelting reactor As far as bulk goods are concerned, this is the case preferably in accordance with comminuted or processed Waste plastic material, especially because of its Hydrocarbon content especially as a substitute for the use of commonly used reducing agents how coal and oil is suitable. About that this bulk material can also be trade other materials, such as Shredder light fractions from automobile recycling, filter dust, Mill scale and the like. To be mentioned in in this context also secondary materials from material collections, that after appropriate preparation meaningful recycling and not simply destruction or combustion should be supplied.

Metallurgical smelting reactors in the sense of the present Blast furnaces, electric furnaces, cupola furnaces, Reactors for direct reduction (e.g. shaft, rotary tube and Fluidized bed furnaces) and reactors for smelting reduction (e.g. meltdown gasifier, iron bath reactors) be. To be blown into these smelting reactors Bulk goods are used in the melting of pig iron mainly raw material (for the generation of reducing gas) and to a certain extent thermally (release of heat). It is therefore a matter of reducing substances or reduction substitutes that - as above mentioned - especially from collected, sorted and appropriately processed secondary materials become. With the method according to the invention these bulk goods an economical and ecological reasonable recovery supplied.

A system according to the invention, in particular for Implementation of the invention described above The process is determined or designed through the sensible combination of the characteristics of the Claim 8 specified features.

The mechanical is particularly advantageous here Discharge and dosing device like a dosing screw trained with adjustable speed drive.

Fig.1

ein grobes Fließschema eines ersten Ausführungsbeispieles der erfindungsgemäßen Anlage;

Fig.2 und 3

je eine Teil-Schemaansicht mit Gutzuführschleusen und Druckgefäßen von zwei weiteren Ausführungsbeispielen der Erfindung.

Further details of the invention result from the following description of some exemplary embodiments with reference to the drawing. Show in this drawing

Fig. 1

a rough flow diagram of a first embodiment of the system according to the invention;

Fig. 2 and 3

each a partial schematic view with material feed locks and pressure vessels of two further exemplary embodiments of the invention.

Before moving on to the various embodiments is received, it should be noted that in the 1 to 3 essentially only the system parts schematically are illustrated or indicated, which for Explanation of the system according to the invention or of it operable process are considered necessary, i.e. the usual fittings necessary for the operation of pneumatic conveyors generally required are assumed to be known per se and therefore essentially not explained and illustrated in more detail.

The example of the invention illustrated in Fig.1 System serves - like the examples according to Fig. 2 and 3 described later - generally for pneumatic Pumping and blowing in hard flowing and bulk material that tends to solidify described type in at least one metallurgical Melting reactor 1, for example - as indicated in Fig.1 - Formed by a blast furnace or the like becomes.

This plant, i.e. the system example according to Fig.1, contains approximately similar to a known pressure vessel conveyor formed pressure vessel 2 with an upper End 2a and a lower end 2b. This pressure vessel 2 has an essentially cylindrical, upright Circumferential wall 3 and an upward, outwardly curved Top wall 3a and one that is curved downwards and outwards Bottom wall 3b, the top wall and bottom wall being fixed the peripheral wall 3 are connected and with this Form pressure vessel 2. On the upper top wall 3a of the Pressure vessel 2 is provided with a shut-off valve 4 Feed pipe 5 connected, the other, upper end with a goods feed lock, container-like pressure lock 6 is connected. That on this way connected to the pressure lock 6 upper End 2a of the pressure vessel 2 is also connected to a compressed gas line 14a connected.

The lower end closed off by the bottom wall 3b 2b of the pressure vessel 2 has a product outlet opening 2b ' with which a mechanical to be explained in more detail later Discharge and metering element 8 of a metering device communicates.

As can be seen in part from the illustration in Fig. 1 lets stand in this plant the melting reactor 1, the delivery pipe 9, the discharge and metering element 8 and the pressure vessel 2 to form an open Printing system in connection with each other, i.e. within This pressure system can pressures unhindered compensate (as already partially mentioned above). Here is a pressure equalization line 7 with the upper one End 2a of the pressure vessel 2 and the good feed point 12 of the delivery pipe 9 connected such that a automatic pressure equalization at least between the upper end of the pressure vessel 2 and the good feed point 12 in the delivery pipe 9, but expedient overall between pressure vessel 2, discharge and metering element 8 and the good feed point 12 is.

According to FIG. 1, a suitable compressed gas or Compressed air source 10 to which the above mentioned Compressed gas line 14a and the pneumatic Delivery pipeline 9 via another compressed gas line 14 is connected, which is a suitable flow control valve 15 contains. The pneumatic delivery pipeline 9 is on the one hand via the mechanical discharge and metering device 8 of the metering device with the good outlet opening 2b 'of the pressure vessel 2 and on the other hand with at least one blowing point, preferably with several Injection points 1a, 1b, 1c, at the counterpressure metallurgical melting reactor 1 connected. Out this is why this pneumatic conveying pipeline 9 at least one multi-way distributor 11 installed, which is any suitable and known from practice Execution, i.e. the distributor can be both static (without moving parts) and also dynamic (with movable fittings) be. From this multi-way distributor 11 leads then a corresponding number of branch conveyor lines 9a, 9b, 9n to each one blowing point 1a, 1b, 1c of the associated melting reactor 1.

The dosing device contains at least one combined mechanical discharge and metering element 8, the designed as a metering screw conveyor or metering screw 8 is. This dosing screw 8 has one in the lower end 2b of the pressure vessel 2 protruding inner End section 8a and one outside the pressure vessel 2 located outer end portion 8b, the with the good feed point 12 of the pneumatic conveying pipeline 9 is connected. The dosing screw is useful 8 motorized by a drive device 13 driven, their speed adjustable is the discharge and dosing performance of this dosing screw 8 to be able to control.

Since in this embodiment according to Figure 1 the pneumatic Delivery pipe 9 after the multi-way distributor 11 contains a plurality of branch conveyor lines 9a, 9b, 9n, each for one injection point 1a, 1b, 1c of the melting reactor 1 lead, it is appropriate to each of these branch conveyor lines one with a flow control valve (As indicated) provided compressed gas sub-line 19a or 19b or 19n to connect to a uniform Distribution of the bulk material to be conveyed to each branch conveyor To be able to ensure 9a, 9b, 9n. These compressed gas sub-lines 19a, 19b, 19n are over a compressed gas line 19 also with the compressed gas source 10 connected. This pressurized gas source 10 thus serves for common care (with appropriate branching) the compressed gas line 14a, the compressed gas line 14 and if necessary also the further compressed gas line 19th

During the pneumatic conveying of the bulk material the corresponding delivery pressure can thus change set correctly that the pressure vessel 2, the dosing screw 8 and the pneumatic conveyor pipe 9 with their feed housing 12 under pressure equalization in the Open printing system mentioned above are integrated. in the Pressure vessel 2 automatically forms an overpressure, to overcome the back pressure in the melting reactor 1. The through the compressed gas line 14 and the compressed gas line 14a (via pressure vessel 2) into the delivery pipeline 9 Quantities of compressed gas are fed in through the flow control valve 15 set. In a way, in the bypass for this purpose, 19 partial quantities each on the compressed gas sub-lines 19a, 19b, 19n distributed to differently increased back pressure at the injection points 1a, 1b, 1c of the melting reactor 1 to be able to compensate. During funding generally most of the compressed gas over the Pressurized gas line 14a into the upper end 2a of the pressure vessel 2 - and partly in the compressed gas line 14 - in supplied in a regulated manner. So that becomes a constant large flow of gas flow through the delivery pipe 9 ensures that constipation the delivery pipeline 9 and the branch delivery lines 9a, 9b, 9n can be prevented. In the course of pressure equalization between pressure vessel 2, dosing screw 8, feed housing 12 and delivery pipeline 9 flows Partial quantity of the compressed gas via the pressure compensation line 7 to the feed housing 12 of the delivery pipeline 9.

For the formation and function of the dosing screw 8 it is also expedient if at least its outer End section 8b is a substantially pressure-tight, tubular Has screw housing 8b ', which - as in Fig.1 can be seen - in the feed housing 12 laterally flows directly. It also opens into this feeder housing 12 essentially from above the pressure compensation line 7, and further to this Feed housing 12 the feed end of the pneumatic Delivery pipe 9 - preferably the confluence of the Pressure equalization line 7 approximately opposite - connected is.

The screw conveyor element 8c of the metering screw 8 can in any suitable manner within the pressure vessel 2 be stored and supported or freely inside protrude (cantilevered), it also being more suitable Shape (paddling, wings or the like) is designed to the bulk material in the pressure vessel 2 in the required Mechanically loosen up and out of the To discharge or discharge pressure vessel 2. For particularly difficult to flow and solidifications bulk goods that tend to form bridges also be advantageous, the screw conveyor element 8c inside the pressure vessel 2 with additional mechanical Loosening elements - as indicated in Fig.1 - equip, which are, for example a loosening spiral, enlarged auger paddles can act or wings.

It is also particularly expedient if the metering screw 8 - as indicated in Fig.1 - approximately radially from the peripheral wall 3 into the interior of the pressure vessel 2 and thus protrudes into the bulk goods.

With the embodiment previously described with reference to FIG. 1 the system is therefore possible to use several Injection points 1a, 1b, 1c of the metallurgical melting reactor 1 simultaneously or alternatively bulk goods the pressure vessel 2 via the multi-branched compressed gas delivery pipeline 9 - preferably in the same size, controllable partial quantities - to be blown in. The filling the pressure vessel can be continuous or discontinuous from the pressure lock 6 - via the feed pipe 5 and the shut-off valve 4 arranged therein. Since this pressure lock 6 also in the manner of a Pressure vessel can be executed, it will also be appropriate to the upper end of this pressure lock 6 shows a branch line 16 indicated by dash-dotted lines Introduce compressed gas line 14a. A suitable one Way connected to the Guteinspeisstelle 12, dash-dotted lines indicated compressed gas sub-line 7a is for Pressure equalization between pressure lock 6 and pressure vessel 2 to initiate the refill process from this Pressure lock 6 in the pressure vessel 2 advantageous. To the upper end of this pressure lock 6 can then in known manner provided with a shut-off valve Gutzuführrohr 17 and possibly a pressure relief line 18 connected.

2 and 3 are two more below Described embodiments in which it are essentially two versions in Area of the pressure vessel to that previously described with reference to FIG. 1 Embodiment is. For this The basic components are the same as those shown in Fig.1 are in Figures 2 and 3 with the same reference numerals, but with the addition of a dash or a double line, so that structural details generally not described in more detail Need to become.

According to the embodiment shown in Figure 2, two or more similarly designed pressure vessels 2 ' a common pressure lock 6 'by one with each a supply pipe 5 'provided with a shut-off valve 4' and simultaneously or alternately with Bulk goods can be filled. Each of these can also Pressure vessels 2 'operated independently of the other be, and each pressure vessel 2 'is with blowing points at least one associated metallurgical smelting reactor via an associated pneumatic delivery pipe 9 'connected, as in principle with reference to Fig.1 in individual has been explained. Each of these two Pressure vessels 2 'is also in the same way as in the pressure vessel 2 of the first embodiment (Fig.1) with a mechanically discharging the bulk material and metering dosing screw 8 '.

3 is the only pressure vessel 2 '' with at least two identical, however, can be operated and regulated separately from one another Dosing screws 8 '' equipped, each one pneumatic conveying pipeline 9 '' with not here injection points illustrated in more detail at least one Melting reactor are connected, also after the same principle, as explained in more detail with reference to Fig.1 has been. Over the pressure vessel 2 '' is again a pressure lock 6 '' arranged (similar to the previous examples).

Finally, it should be mentioned that all pressure vessels on their bottom wall with a suitable - known per se and therefore not illustrated in more detail - floor or Residual emptying device can be provided.

Claims (15)

Process for the pneumatic conveying and blowing of bulk material which is difficult to flow and tends to solidify, in particular of essentially granular plastic material, secondary recyclable material or the like, into at least one metallurgical melting reactor (1), the bulk material from the lower end (2b) being pressurized with compressed gas at excess pressure Pressure vessel (2, 2 ', 2'') fed into at least one pneumatic delivery pipeline (9, 9', 9 ''), conveyed therein to at least one injection point (1a, 1b, 1c) of the melt reactor under pressure and into this melt reactor is blown in
characterized by the following features: a) the bulk material is mechanically challenged from the lower end (2b) of the pressure vessel (2, 2 ', 2'') using a combined discharge and metering element (8, 8', 8 '') and metered into the delivery pipe ( 9, 9 ', 9''); b) melting reactor, delivery pipeline, discharge and metering element and pressure vessel are connected to form an open pressure system, c) wherein at least between the upper end (2a) of the pressure vessel (2, 2 ', 2'') and the feed point (12) in the conveyor pipe, an automatic pressure compensation is established. A method according to claim 1, characterized in that the bulk material with a grain size or piece size conveyed by up to about 25 mm and in the Melting reactor (1) is blown. A method according to claim 2, characterized in that the bulk material is at least partially in the form of to agglomerates or pellets processed plastic material used and as a reducing agent in a molten metal is blown in. A method according to claim 1, characterized in that the bulk material within the pressure vessel (2, 2 ', 2 '') through the discharge and metering element (8, 8 ', 8 '') is loosened mechanically at the same time. A method according to claim 1, characterized in that at several injection points (1a, 1b, 1c) one metallurgical melting reactor (1) simultaneously or alternatively bulk goods from the pressure vessel (2, 2 ', 2 '') via the multi-branched delivery pipe (9, 9 ', 9' ') is blown in. A method according to claim 1, characterized in that from a pressure vessel (2 '') several metallurgical Melting reactors simultaneously or optionally via a delivery pipe (9 '') with bulk material be supplied. A method according to claim 1, characterized in that from several operated in parallel Pressure vessels (2 ') pneumatically the bulk material promoted metallurgical smelting reactors and is injected in doses there. System for the pneumatic conveying and blowing of bulk material which is difficult to flow and tends to solidify, in particular of essentially granular plastic material, secondary material or the like, containing at least one metallurgical melting reactor (1) a) wengistens a pressure vessel (2, 2 ', 2''), which is connected at its upper end (2a) to a material feed lock (6, 6') and a compressed gas line (14a) and one at its lower end (2b) Good outlet opening (2b '), b) at least one pneumatic delivery pipe (9, 9 ', 9'') connected to a compressed gas source (10), which on the one hand has a mechanical metering device with the product outlet opening (2b') of the pressure vessel and on the other hand has at least one blowing point (1a, 1b, 1c) is connected to the metallurgical melting reactor (1) which is under counterpressure,
characterized by the following features: c) the metering device contains at least one combined mechanical discharge and metering element (8, 8 ', 8'') which has an inner end section (8a.) projecting into the lower end (2b) of the pressure vessel (2, 2', 2 '') ) and has an outer end section (8b) connected to a feed point (12) of the delivery pipeline (9, 9 ', 9'') and can be driven in a controllable manner; d) Melting reactor (1), conveying pipeline (9, 9 ', 9''), discharge and metering element (8, 8', 8 '') and pressure vessel (2, 2 ', 2'') form an open one Pressure system in connection with each other, wherein a pressure equalization line (7) connected to the upper end (2a) of the pressure vessel connects this upper end (2a) of the pressure vessel to the good feed point (12) of the conveying pipeline with the production of an automatic pressure equalization. System according to claim 8, characterized in that the mechanical discharge and metering device according to Art a dosing screw (8, 8 ', 8' ') with in its Speed-adjustable drive (13) is formed. Installation according to claim 9, characterized in that at least the outer end portion (8b) of the dosing screw (8, 8 ', 8' ') an essentially pressure-tight, has tubular screw housing (8b '), that directly into the infeed point of the Delivery pipeline (9, 9 ', 9' ') forming Feed housing (12) opens, which also essentially from above with the pressure compensation line (7) communicates and to the feed end the delivery pipeline - the confluence of the pressure compensation line (7) approximately opposite connected. Installation according to claim 9, characterized in that the screw conveyor element (8c) of the dosing screw (8, 8 ', 8' ') inside the pressure vessel (2, 2', 2 '') with additional mechanical loosening elements Is provided. The system of claim 9, wherein the (each) pressure vessel (2, 2 ', 2' ') an essentially cylindrical, upright Has peripheral wall (3) and outwardly curved bottom and top walls (3a, 3b), characterized in that that the dosing screw (8, 8 ', 8' ') approximately radially from the peripheral wall (3) into the interior of the pressure vessel (2, 2 ', 2' ') protrudes and that on the top cover wall (3a) of the pressure vessel with a Shut-off valve (4, 4 ') provided feed pipe (5, 5 ') is connected, the other end with a pressure vessel-like pressure supply forming the feeder lock Pressure lock (6, 6 ', 6' ') is connected, preferably also via a branch line (16) connected to the compressed gas line (14a) is. Plant according to claim 12, characterized in that at least two similarly designed pressure vessels (2 ') to a single pressure lock (6') by one Good feed pipe provided with a shut-off valve (4 ') (5 ') connected and simultaneously or alternately can be filled with bulk material, each Pressure vessel (2 ') can be operated independently of the other and with the injection points of at least one metallurgical one Melting reactor via an associated pneumatic Delivery pipe (9 ') is connected. Installation according to claim 9, characterized in that in every pneumatic conveyor pipe (9, 9 ', 9' ') at least one multi-way distributor (11) is installed, of the branch conveyor lines (9a, 9b ... 9n) each a blowing point (1a, 1b, 1c) of the associated Guide the melting reactor (1) to all branch feed lines one with a flow control valve Provided compressed gas partial line (19a, 19b, 19n) for a controlled addition of feed gas to each branch feed line connected. Installation according to claim 9, characterized in that the pressure vessel (2 '') with at least two of the same type trained, but can be operated separately from each other and adjustable dosing screws (8 '') is, each via a pneumatic conveyor pipe (9 '') with the injection points at least one Melting reactor are connected.

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