LU86818A1 - METHOD AND DEVICE FOR COOLING A LOADING INSTALLATION OF A TANK OVEN - Google Patents

Description

ß Q ~ ï ~ 0 ßRAND-DUCHE DE LUXEMBOURG BL-4010 Ö Ο! O. MonsieurleMinistre of March 24, 1987 (¾¾¾ of the Economy and the Middle Classes

Intellectual Property Service

Title issued LUXEMBOURG

ï

Patent Application

-.........................-....................... ......... ..............................-.......... . ............-. (U

I. Request

The so-called company: PAUL WURTH S.A., 32. rue d'Alsace. BP2233_________________________ (2) ............................................. .............................. LUXEMBOURG ................... ............................................. -.... .................................... — ............. ..

represented by: E.T.FREYLINGER & E.MEYERS, ing. -c.ons * _en -propr * -ind., (3) 46, rue du cimetière, LUXEMBOURG, agents ................... ...... ...._............

deposit (s) this twenty ..... March four thousand ..... nine ..... one hundred and four "twenty -seven -----— (41 to ... 15, 00 .... ..— hours, at the Ministry of the Economy and the Middle Classes, in Luxembourg: 1. this request for obtaining a patent for an invention concerning: ............. .................................................. .................................................. .......................-.......................... .................................................. ........................................... (5)

METHOD AND DEVICE FOR COOLING ..... OF IINF. TNSTAT.T.ATTnN DE

LOADING ..... FROM A TANK OVEN .................-.................... .................................................. ....... ........................................... ..................

2. description in French .............. language ............................. ..................... of the invention in three copies: 3 .................... ................... 3 ................ drawing boards, in three copies: 4. the tax receipt paid to the Luxembourg Registration Office on ______ 24 jnars 1987 .................; 5. the delegation of power, dated ....... Luxembourg ..........-...................... ............. on ............., 2-3 -March ..... 1987 .....-..... ..

6. the pre-cause document (authorization); declare (s) assuming responsibility for this declaration, that the inventor (s) is (are): (6). "Claims (s) for the above patent application the priority of one (s) request (s) of (7) ....................... .................................................. ..... J ............................................ ............................ filed in (8) __________________ / ._.......... ..................: ___.............

on (9) .............................................. .................................................. .................................................. ........ L__________________________________________________________________________________________________________________ under N ° (10) .................................. .................................................. ....................... L_________________________________________________________________________________________________________ on behalf of (11) .................... .................................................. ............. — .............................. L .___________________________________________________________________________________________________________ elect (elect ) domicile for him (her) and, if designated, for his representative, in Luxembourg______ ____________________ 46, ....... rue du ..... cemetery. Luxembourg__________________________________________________________ (12) requests (s) the grant of a patent for the invention for the subject described and represented in the abovementioned appendices, with postponement of this grant to ............... ........._......... eighteen __________ — ________________________________________________________ month. (13)

The deffMSfiMt / agent: .....................____________________________________________________________________________________________________________________ (14) \ · Π. Deposit Minutes

The above patent application has been filed with the Ministry of the Economy and the Middle Classes, Property Service InteUed ^ lle iTjukembourg, dated: March 24, 1987 / ff * w [§ '*%, y' · · 5 · \ Pr. The Minister of Economy and the Middle Classes.

at 15.0.0. hours I *: ’\ = § | p. d.

> ç / The head of the intellectual property department.

A68007__ EXPLANATION RELATING TO * DEPOSIT FORM.

(11 if applicable "Application for certificate of addition to the main patent, to main patent application No ............ of ........... (2) enter the last name, first name, profession address of the applicant, when the latter is an individual or corporate name, legal form, address of head office, when the applicant is a legal person - Î3 »enter the names. first name- address of professional representative, industrial property attorney, with special powers, if applicable: "represented by ........... acting as representative" *. r BL-4010 Descriptive memory filed in support of a patent application for: PROCESS AND DEVICE FOR COOLING A LOADING INSTALLATION OF A TANK OVEN.

PAUL WURTH S.A.

32, rue d'Alsace B.P. 2233 Luxembourg * BL-401Ο METHOD AND DEVICE FOR COOLING a loading installation of a shaft furnace

The present invention relates to a method and a device for cooling a loading installation of a shaft furnace, comprising a fixed supply channel arranged vertically in the center of the head of the furnace, a rotary ferrule mounted coaxially around said feed channel, a fixed external carcass mounted coaxially outside said ferrule and laterally delimiting therewith a substantially annular chamber, this chamber being separated, but not isolated, from the interior of the furnace by means of a rotary cage integral with the rotary ferrule, a distribution chute pivotally mounted in the rotary cage, a drive means for rotating, as a unit, the ferrule and the cage around the vertical axis of the oven and the feed channel, an annular feed tank fixed to the upper edge of the rotating ferrule and whose outer and inner concentric walls slide in concentric grooves of a plate fixed upper plate crossed by at least 20 a cooling water inlet pipe supplying the annular tank, several cooling coils arranged around the rotary cage and each connected by a pipe to said annular tank, a circular collector fixed to the carcass outer and 25 pipes connecting each of the coils to the collector, so that water flows between the annular tank and the collector through said pipes and the coils.

The first liquid cooling device 30 of this kind used for a loading installation of a shaft furnace is proposed in document EP-B1-0116142. Despite all the precautions and arrangements made in this known cooling device, it has been found that dust and dirt, albeit in small quantities, manage to get into the coolant. It has been found that most of the dirt is introduced through the upper edges of the feed tank, either from the central feed channel or from the annular chamber around the rotary cage. These dirt deposits in the coils and necessarily reduce the section thereof. This not only causes a reduction in the speed of circulation of the coolant and, consequently, an increase in the risks of deposition, but also by the insulating layer formed by these deposits, a reduction in the cooling power.

The object of the present invention is to improve the known liquid cooling device described above so as to reduce the penetration of dust and dirt in the cooling circuit.

To achieve this objective, the present invention proposes a liquid cooling process which is essentially characterized in that an inert gas or purified blast furnace gas is injected into the annular supply tank at a pressure greater than 25 that prevailing inside the oven and lower than the pressure for injecting water into the tank.

Thanks to this gas injection, a double result is obtained. Indeed, by creating above the level of liquid in the tank a pressure greater than that prevailing in the oven, it prevents, or at least reduces the penetration of gases charged with dust in this tank. In addition, by creating a certain pressure above the upper level of the cooling water, an increase in the height of the water is simulated, i.e. increase the speed of circulation in the coils and this results in better cooling and a reduction in the risk of deposits forming in the coils.

As an auxiliary measure, the penetration is reduced 3. .

tration of the gases charged with dust in the annular chamber using the collector as a liquid barrier between the furnace and this annular chamber. In addition, the oven gases are forced, despite everything succeeding in crossing said liquid barrier, in passing through a curtain of water which serves to wash the gases and to precipitate the solid particles.

It is advantageous to provide a settling tank in the cooling circuit to cause the deposition of solid particles of the coolant and to be able to reuse it.

The installation intended for the implementation of this process is characterized in that the annular supply tank is connected to a gas line under pressure through a gas distribution pot. The rotary cage preferably includes a peripheral lip descending to the bottom of the manifold and defining with the inner wall thereof a labyrinth of gas passage.

According to an advantageous embodiment, a circular lining of sprinklers is provided in the carcass above the manifold, these sprinklers each producing a jet of water in an open fan, directed on the lip of the rotary cage so as to form a curtain 25 of uninterrupted water above the collector.

This collector is preferably connected to the first compartment of a settling tank, which is separated from the second compartment of this same tank by a vertical partition extending from the bottom 30 to the upper region of the tank, this second compartment being connected to the auxiliary cooling water supply and to the recycling circuit.

Other particularities and characteristics will emerge from the detailed description of an advantageous embodiment, presented below, by way of illustration, with reference to the appended drawings in which: 4 jr * t Figure 1 shows a schematic view of the assembly of a cooling installation of the kind described in the aforementioned document and provided with the improvements proposed by the present invention; Figure 2 shows, in a sectional view, the details of the coolant supply tank; Figure 3 shows, in a sectional view, the details of the coolant collector and Figure 4 shows a view of the curtain of liquid formed above the collector.

FIG. 1 schematically shows the device for driving a distribution chute of a loading installation of a shaft furnace, provided with a liquid cooling device of the kind proposed in the aforementioned document.

This mechanism essentially comprises two sets of gears 14 and 16 respectively serving for the rotation of a ferrule 18 about the central axis of the furnace for the purpose of the rotation of the distribution chute, not shown in the figure, around the longitudinal axis of the oven and the angular adjustment of this chute with respect to this longitudinal axis. The transmission of the movements and the suspension of the mobile elements are re-used, in a manner known per se, by means of bearings 22, 28 (see FIG. 2) and will not be described in detail in the context of this request.

An external carcass 24 laterally delimits with the rotary ferrule 18 an annular chamber 26. This annular chamber is separated from the interior of the furnace by a suspension cage 30 of the chute, this cage being integral with the rotary ferrule 18.

As in the known liquid cooling device, the rotary cage 30 is externally lined with cooling coils 32 to prevent this cage 30 from transmitting, either by conduction or by radiation, the heat to other parts, such as eg bearings and gears. The various serpentines 32 are connected through connection pipes 38 to an annular feed tank 40 attached to the upper part of the shell 18 and therefore rotating with the latter around the vertical axis.

As in the known cooling device, the cooling water flows, by gravity, through the coils 32 in a circular collector 60 provided around the bottom of the rotary cage 30. From this collector 60, the water from cooling is recirculated through a settling tank 80, a pumping unit 82, a self-cleaning filter 84 and a cooling circuit 86 in conduits 54 supplying the annular tank 40. Reference will be made to the aforementioned document EP-B1- 0116142 for further information about details of the cooling system and its operation.

As can be seen in FIG. 2, the upper edges of the feed tank 40 evolve without contact in concentric circular grooves 46, 48 of an upper fixed plate 44 welded to the carcass 24. The feed of the tank 40 cooling water is produced through a circular groove 52 in the plate 44, into which the supply line (s) 54 open (s) (see FIG. 1).

25 As can be seen in FIG. 2, the opening between the upper edges of the tank 40 and the grooves 46, 48 has been deliberately designed as a labyrinth to reduce the risk of gas and dust passing through the tank 40 and to create a pressure drop for the sealing gas described below. Despite these labyrinth-shaped openings, dust has been penetrated into the tank 40, essentially coming from the gases rising from the interior of the oven through the shell 18.

According to the present invention, the risks of dust penetration into the tank 40 are reduced by injecting therein, through one or more pipe (s) 56, an inert gas or blast furnace gas 6 ",.

purified under pressure, eg nitrogen. This gas is injected at a pressure slightly higher than that prevailing in the shaft furnace in order to prevent the penetration of gas through the grooves 46 and 48f and at a pressure lower than the pressure of the water in the pipes. inlet 54 so as not to prevent the penetration of cooling water into the tank 40. This pressurized gas enters the tank 40 through an annular distribution pot 58 with a perforated wall.

The present invention also provides measures to reduce the penetration of dust into the annular chamber 26 so as to thereby reduce the access of dust into the tank 40 and to spare the gears and bearings from dust deposits. . In fact, there must necessarily be a circular slot between the rotary ferrule and the fixed carcass 24. Now, the pressure fluctuations inside the oven create a pumping effect between the chamber 26 and the inside of the oven through this slit, which favo-20 makes the passage of small quantities of gas charged with dust in the chamber 26.

To overcome this drawback, the collector 60 is designed in the form of a circular tank, of rectangular section integrated into the carcass 24. The lower edge 25 of the rotary cage 30 has a vertical peripheral lip 62 which extends from above from the inner edge of the manifold 60 to the bottom thereof, without however being in contact with this manifold 60. The passage formed around the inner wall of the manifold 60, 30 on the one hand, and the edge of the rotary cage 30 and its lip 62, on the other hand, is also voluntarily encumbered by a peripheral circular lamella 64 of the cage 30 which evolves, during the rotation of this cage 30, in a groove 64 arranged on the inner wall of the collar 35 reader 60. The labyrinth defined by the shape of this passage and by the lamella 64 and the groove 66 therefore opposes the passage of gases and dusts from the interior of the oven to the collector 60.

»,» 7

In addition, it is possible to provide measures to ensure a minimum level of liquid in the collector 60 so that the bottom edge of the book 62 is inside the liquid and that is formed, 5 , a liquid barrier between the interior of the oven and the chamber 26.

As an additional measure, in an advantageous embodiment, there is provided, above the external edge of the manifold 60, a circular lining of 10 nozzles 68 through which one injects, through pipes 72 connected in bypass on the main circuit (see Figure 1) cooling water. Each of the nozzles 68 forms, as shown in FIG. 4, a jet of water 70 in the form of a wide fan directed on the lip 62. The combined effect of all the nozzles 68 thus makes it possible to form a curtain of uninterrupted water covering all the collector 60 and ensuring an effective rinsing of the gases which manage, despite everything, to penetrate by the labyrinth in the collector 60.

The collector 60 is connected by pipes 74 to a settling tank 80 (see FIG. 1). This reservoir 80 is separated by means of a vertical partition 92 extending from the bottom to the upper region, into two compartments 88 and 90. The water coming from the collector 60 is introduced into the compartment 88 where solid particles can settle at the bottom, while decanted water can only pass into the second compartment 90 over the partition 92. This compartment 90 is also connected 30 to a supply line 94 for supplying of the make-up water circuit to replace the evaporated water. The water is extracted from the base of the reservoir 80 by the pump group 82 and returned, in a manner known per se, in the cooling circuit via the filter 84. The two compartments 88, 90 of the settling tank 80 can be drained by a group of valves 96, in particular to remove solid deposits from compartment 88.

*.

8

It remains to emphasize that the improvements proposed by the present invention can be easily adapted to existing installations of the kind described in document EP-B1-0116142.

Claims (8)

1. A method of cooling a loading installation of a shaft furnace, comprising a fixed supply channel (20) arranged vertically in the center of the furnace head, a rotary ferrule (18) 5 mounted coaxially around said channel (20), an outer carcass (24) mounted coaxially outside of said ferrule (18) and laterally delimiting therewith a substantially annular chamber (26), this chamber (26) being separate, but not insulated, from inside the oven by means of a rotary cage (30) integral with the rotary ferrule (18), a distribution chute pivotally mounted in the rotary cage (30), a drive means for rotating , in block, the ferrule (18) and the cage (30) around the vertical axis and the feed channel (20), an annular feed tank (40) fixed on the upper edge of the rotary ferrule (18) and whose two outer and inner concentric walls slide in concentric grooves (46, 48) of an upper fixed plate (44) crossed by at least 20 a cooling intake pipe (54) supplying the annular tank (40), several cooling coils arranged around the cage (30) and each connected by a pipe (38) to said annular tank (40), a circular collector (60) fixed to the external carcass 25 (24) and pipes connecting each of the coils to said collector (60), so that the water flows between the annular tank (40) and the manifold (60) through said pipes and coils, characterized in that an inert gas or purified blast furnace gas is injected into the annular tank (40) at a pressure higher than that prevailing inside the oven and lower than the pressure for injecting water into the tank (40). 2. Method according to claim 1, characterized in that the collector (60) is used as a liquid barrier between the oven and the annular chamber (26). 3. Method according to claim 2, characterized * - N \ \, 1 V) 10 in that one obliges the oven gases succeeding in passing said liquid barrier to pass through an uninterrupted curtain of water above the collector (60) . 4. Method according to any one of the claims 5 cations 1 to 3, characterized in that one causes a settling of the cooling water in a settling tank (80). 5. Installation for the implementation of a method according to any one of claims 1 to 4, 10 characterized in that the annular supply tank (40) is connected to at least one pipe (56) of gas under pressure through a gas distribution pot (58). 6. Installation according to claim 5, 15 characterized in that the rotary cage (30) has a peripheral lip (62) descending to the bottom of the collector (60) and defining with the inner wall thereof a passage labyrinth gases. 7. Installation according to claim 6 carac-20 terized by a circular lining of sprinklers (68) provided in the carcass (24) above the collector (60) and each producing a jet of water (70) in an open fan directed on the lip (62) of the rotary cage (30) so as to form an uninterrupted curtain of water above the collector (60). 8. Installation according to claim 6, characterized in that the collector (60) is connected to the first compartment (88) of a settling tank (80), which is separated from the second compartment (90) of this same tank ( 80) by a vertical partition (92) extending from the bottom of the tank to the upper region thereof and in that the second compartment (90) is connected to an additional supply of cooling water and to the cooling water recycling circuit.