US3183537A - Apparatus for use in the granulation of iron - Google Patents

Description

H. E. STORR 3,183,53 7

APPARATUS FOR USE IN THE GRANULATION OF IRON 4 Sheets-Sheet 1 May 18, 1965 Original Filed Aug. 16, 1961 'III lull

" HHIHIIIHHIII E Inventor b14190) [R /c 52-00? 22 z W Attorneys H. E. STORR 1 3,183,537

APPARATUS FOR USE IN THE GRANULATION OF IRON 4 Sheets-Sheet 2 May 18, 1965 Original Filed Aug. 16, 1961 Inventor fimr 6% $702? By W W '6 Attorneys y' 1965 H. E. STOR'R 3,183.;537

APPARATUS FOR USE IN THE GRANULATIQN or IRON ori inal Filed Aug. 16, 1961 4 sheets-Shea: :5

lnvenlor fihkm fP/c 5mm? Attorneys May 18, 1965 H. E. s'roRR 3,133,537

MPARA'TUS FOR USE IN THE GRANULATION OF IRON @ri ginal Fil ed Aug. 16, 1961i. 4 Sheets-Sheet 4 A ttorneys United States Patent C) 3,183,537 APPARATUS FOR USE IN THE GRANULATION F IRON Hardy Eric Starr, 21 Penfold Drive, Great Billing, Northampton, England Original application Aug. 16, 1961, Ser. No. 131,801. Divided and this application Oct. 2, 1963, Ser. No. 313,396

4 Claims. (U. 18-2.7)

' This application is a division of my copending application, Serial No. 131,801, filed August 16, 1961.

This invention relates to apparatus for use in converting molten iron to granules of smoothly contoured, or rounded or globular shape by a method comprising directing a stream of molten iron through the atmosphere, subjecting the molten iron stream to the action of jets of water to create a shower of hot iron particles and water, and collecting the falling shower in a vessel containing water through which the particles of the shower sink, the water of the jets and the water in the vessel being maintained at such high temperatures that the particles from the moment they are created are protected against chilling and cool slowly to form granules of smoothly contoured or rounded or globular shape. Such a method forms the subject of my co-pending patent application Serial Number 131,801, filed August 16, 1961. More particularly, the apparatus to which this invention relates comprises a conduit for directing a stream of molten iron through the atmosphere, a plurality of nozzles arranged below said conduit to direct jets of high-temperature water on to the molten iron stream and thereby create a shower of hot iron particles and water, a vessel for high-temperature water into which the shower falls and through which the hot iron particles sink, a collecting hopper in the vessel, and a conveyor extending from the hopper outlet, the hopper serving to direct the sinking particles on to the conveyor which serves to carry the particles from the vessel.

The use of high-temperature water to effect gradual cooling of the granules means that there is a risk of dangerous eruption of the contents of the vessel, and that the granules are relatively hot when they reach the conveyor and tend to destroy the conveyor belt by burning. Also, the smoothly contoured or rounded or globular shape of the granules deposited on the conveyor belt means that the granules tend to spill laterally from the conveyor belt into the vessel so that the eflicieney of the conveyor is reduced.

The object of the invention is to provide granulating apparatus which enables the foregoing method to be carried out continuously with a maximum of safety and efficiency, and without burning the conveyor belt.

The molten metal will usually be taken either (a) from a blast furnace tap hole, or (b) from hot metal ladles. In the case of (a) a plurality of units would normally be required to deal with the variable iron flow, from the blast furnace, the first unit automatically taking its predetermined rate of iron flow, any excess flowing on to the next unit and so on. In the case of (b) the rate of iron flow can be regulated to the maximum the unit would take.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a top plan view of an iron-granulating apparatus.

FIG. 2 is a sectional elevation on the line A-A of FIG. 1.

FIG. 3 is a fragmentary top plan view of supply means for cooling water, the piping being symmetrical about the longitudinal centre lines of the hoppers.

FIG. 4 is a transverse sectional view at the bottom of the collecting vessel.

FIGS. 5 and 6 are respectively side and end views of a metal conduit and its jet head, and

FIGS. 7 and 8 are respectively a front view and a transverse sectional view of a weir on the collecting vessel.

Referring to the drawings:

Pig-iron from a blast furnace is poured into a tipping ladle 1 which an electrical hoisting winch 2 controlled from a control room 3 causes to tip gently and regularly. The winch 2 is equipped with variable speed driving motor and gear to ensure a constant rate of iron discharge at all levels of metal in the ladle, and a quick return of the empty ladle to receiving position. The ladle discharges the molten iron into a container or surge pool 4 with side walls funnelled towards an opening through which the metal passes into the top end of a downwardly sloped sand-lined conduit 5 which divides to form pairs of sand-lined branch conduits 6 and 7. At the bottom end of each branch conduit 6, 7 is mounted a block 8 of refractory material, preferably carbon, of appropriate size and shape controlling the flow of molten iron from the branch conduit. The molten iron flows in the form of a wide ribbon 9 from the bottom end of the branch conduit and falls in a wide ribbon through the atmosphere.

Immediately below the bottom end of each branch conduit 6, 7 is a water-jet or spray head 10 containing a plurality of jet openings 11 which direct the water outwards in substantially horizontal streams. Assuming the falling molten metal ribbons to be nearly vertical, the water jets from the heads impinge on the ribbons at approximately right angles. The water jets break up the ribbons into particles and spread the particles horizontally in showers. The jet heads 10 are fed with hot water from a suitable source by a high-pressure pump (not shown), and the flow of hot, pressure water to each jet head is through a pipe 12 and a valve 13. The temperature of the hot-water jets is in the range 60 70 C.

The shower of hot metal particles and water produced by the hot-water jets fall into a tank 14 of water which is maintained at a high temperature of not less than 80 C., but not higher than 95 C. as the tank contents might then erupt. .The desired level X of hot water in the tank 14 is maintained by two weirs 15 and 16 at opposite ends of the tank. The Weir 16 includes a plate 17 secured to the weir wall by bolts 18 extending through vertical slots 19 in the plate which is thus vertically adjustable to vary the Weir level. A channel 20 delivers the overflow to a settling tank 21 from which the water is discharged to waste through a pipe 27.. A pair of collecting hoppers 23 and 24 submerged in the tank 14 and associated respectively with conduit pairs 6 and 7, are elongated in the general direction of issue of the water jets and receive the particles as they sink through the water. The hoppers have their elongated open bottoms aligned with the upper runs of a pair of upwardly sloped endless-belt conveyors 2'5 and 26 so that the particles fall though the hoppers on to the conveyors. The longitudinal side walls 27 (FIG. 4) of each hopper 23, 24 terminate closely adjacent to the longitudinal edges of its conveyors upper run 28, and a pair of longitudinal rubber strips 29 secured to the respective lower ends of the side walls maintains continuous frictional engagement with the top faces of the longitudinal marginal portions of the upper run 28 to prevent lateral spilling of the globular granules from the upper run. Each hopper has internal louvre plates 30 spaced from the side plates 27 to define upwardly extending passages for the escape of hot water upwards from the region of the conveyor so that there is free circulation of the water in the hopper.

Supply piping 31 (FIG. 3) for cooling water extends from a source of cooling water and is connected to the hoppers 23, 24 at the ends of the hoppers adjacent to the jet heads and at a level spaced below the water level in the tank 14 and lying above the submerged upper run of the conveyor. The piping discharges into the hoppers in directions across the downward paths of the heavier particles sinking through the hoppers. One or more of the following three piping arrangements are provided for the hoppers:

(1) At each hopper a pair of parallel longitudinal valve-controlled supply pipes 32, 33 communicate with a transverse manifold pipe 34 at the end of the tank adjacent to the nozzles, and cold Water is supplied from a source to the pipe 34 by a pump. The discharge ends 32A, 33A of the pipes 32, 33 converge to direct convergent streams of cooling water towards a zone 35 which is about midway of the hopper depth and at the end of the hopper adjacent to the nozzles. The streams form a cooling layerthrough which the heavy iron particles fall.

(2) At each hopper, a pair of parallel, valve-controlled supply pipes 36 and 37 open from the manifold pipe 34 and discharge parallel jets of cooling water into the hopper 24 to form a cooling layer immediately above the conveyor.

(3) For serving both hoppers, three parallel, valvecontrolled supply pipes 38 communicate with the manifold pipe 34 and slope upwards alongside the exterior of the hopper side walls. Opposed series of branch pipes 39 and 40 project through the hopper side walls to discharge into the hoppers at locations immediately above the conveyors. In an alternative shown in FIG. 4, supply pipes 41 have branch pipes 42 extending downwards behind the louvre plates 30 and discharging immediately above the conveyor.

The addition of the cooling water to the tank can be varied to suit variations in the temperature of the tank water arising during operation of the apparatus, such temperature variations being noted for instance by continuous temperature recording. Thus, the cooling water is used to prevent the tank water from becoming too hot (the temperature must not exceed 95 C.), and also to provide a layer of cooling water midway of the hopper depth and/or immediately above the conveyor, and at the end of the hopper adjacent to the nozzles, so that the heavier particles sinking through the hopper pass through, successively, a layer of high-temperature water and a layer of cooling water, cooled sufliciently by the cooling layer to prevent burning of the belt.

The conveyors 25, 26 are motor-driven through variable-speed gearing, so that the speed of passage through the water of the particles on the submerged conveyor runs is closely regulable.

By controlling the flow of cooling water and/or the speed of the conveyors, it is possible to control the cooling of the granules and so ensure that sufficient heat is retained by the granules leaving the tank to dry the granules in the course of subsequent handling.

As the metal granules settling on the submerged conveyors retain some of their heat, the conveyorbelts are made of a heat-resistant material e.g., a suitable rubber, or steel of a special woven mesh construtcion.

The granules are delivered by the conveyors 25, 26 clear of the tank, into suitable equipment for road or rail loading, or for direct belt feeding to storage bins or for stacking on the ground.

While a variety of designs of jet heads are possible, good results are obtained with jet heads each containing 7 horizontal rows of /2" diameter jet holes, the rows comprising alternately 13 and 12 jet holes. Said jet heads operate at 7 lbs/in. measured in line 4 feet from the heads. For this particular condition, the ribbon of molten iron is 6 /2 inches wide and /8 inch thick, but larger ribbon widths are used in larger capacity plants. The hoppers are at least 11 it. deep to give sutficient depth and reserve of water to accommodate the high water temperatures.

In operation of the apparatus, to obtain a product of high. bulk density and large average particle size, the tem perature of the molten iron ribbon is maintained as high as possible, and the flow-rate of the molten iron is reduced somewhat ifthere is any fall in the iron temperature, Thus, with molten iron at 1300 C., a minimum flow rate of molten iron of about 0.22 ton/minute per 1 inch width of ribbons produces spherical particles of about 0.32 inch diameter and with a bulk density of about 270 lbs/cu. ft. With molten iron at 1150 C., this flow rate requires reduction to the order of 0.195 ton/min./ inch.

It is found that the hot-water treatment of the molten metal results in a smoothly contoured or rounded or globular granule,which lends itself to easy bulk handling, whereas cold-water treatment of the molten metal results in a granule which isragged and angular.

Moreover, in one example thehot water product has a bulk density of 289 lbs./ cu. ft. as against only 2-30 lbs./ cu. ft. for thecold-water product.

Also, surprisingly, the screen size of the hot-water gran-ules is generally larger than that of the cold-water granules with respect to passage'through a sieve; and the hot-water granules are more uniform in size than the cold-Water granules.

This invention is also applicable to apparatus for use in the treatment of molten slag, and in the. following claims the term iron is for convenience used to mean iron or slag.

I claim:

1. Apparatus for use in converting molten iron to granules of smoothly contoured or rounded or globular shape comprising a conduit for directing a stream of molten iron through the atmosphere, a plurality of nozzles arranged below said conduit to direct jets of high-temperature water on to the molten iron stream and thereby create a shower of hot iron particles and water, a vessel for hightemperature water into which the shower falls and through which the hot iron particles sink, a collecting hopper in the vessel, and a conveyor extending from the hopper outlet, the hopper serving to direct the sinking particles on to the conveyor which serves to carry the particles from the vessel, wherein'a supply pipe for cooling water is connected to the hopper ata level spaced below that of the high-temperature water in the vessel, and is adapted to discharge'the cooling water into the hopper across the downward path of the particlesthrough the hopper, so that the particles sink through, successively, a layer of high-temperature water and a layer. of cooling Water.

2. Apparatus according to claim 1, the hopperv being elongated in the general direction of issue of the water jets, and the conveyor being of the endless-band type and extending along the hoppers elongated outlet opening, wherein said outlet opening has at its longitudinal sides a pair of resilient longitudinal strips frictionally engaging the longitudinal marginal portions of the conveyors upper run to prevent lateral spillage of granules from the conveyor.

3. Apparatus according to claim 1, the hopper being elongated in the general direction of issue of the water jets, and the conveyor extending along thehoppers elongated outlet opening, wherein the supply piping for the cooling water is connected to the end of the hopper adjacent to the jet nozzles so as toprovide a layer of cooling water for the heavier of the hot particles sinking towards the conveyor.

4. Apparatus for use in converting molten iron to granules of globular shape comprising a conduit for directing a stream of molten iron through the atmosphere, a plurality of nozzles arranged below said conduit to direct jets of high-temperature water on to the molten iron stream and thereby create a shower of hot iron particles and water, a vessel for high-temperature water into which the shower falls and through which the hot iron particles sink, a collecting hopper in the vessel elongated in the general di- 5 6 rection of issue of the water jets, and an endless-band con- References Cited by the Examiner veyor aligned with and extending from the elongated out- UNITED STATES PATENTS let of the hopper the hopper serving to direct the sinking 1,865,367 6/32 Gorsuch 6521 partlcles on to the conveyor WhlCh serves to carry the 2,137,931 11/38 Craven et a1 65 21 particles from the vessel, wherein the hopper has at its 5 flonglaltted outlet at tafiiir 10f reisilcilentllongitudirial strtips fric FOREIGN PATENTS 1ona y engaging e ong1u ma margma por1ons o the conveyors upper run to prevent lateral spillage of 8o0O70 8/58 Great Bntam granules from the conveyor. WILLIAM J. STEPHENSON, Primary Examiner.

Claims (1)

1. APPARATUS FOR USE IN CONVERTING MOLTEN IRON TO GRANULES OF SMOOTHLY CONTOURED OR ROUNDED OR GLOBULAR SHAPE COMPRISING A CONDUIT FOR DIRECTING A STREAM OF MOLTEN IRON THROUGH THE ATMOSPHERE, A PLURALITY OF NOZZLES ARRANGED BELOW SAID CONDUIT TO DIRECT JETS OF HIGH-TEMPERATURE WATER ON TO THE MOLTEN IRON STREAM AND THEREBY CREATE A SHOWER OF HOT IRON PARTICLES AND WATER, A VESSEL FOR HIGHTEMPERATURE WATER INTO WHICH THE SHOWER FALLS AND THROUGH WHICH THE HOT IRON PARTICLES SINK, A COLLECTING HOPPER IN THE VESSEL, AND A CONVEYOR EXTENDING FROM THE HOPPER OUTLET, THE HOPPER SERVING TO DIRECT THE SINKING PARTICLES ON TO THE CONVEYOR WHICH SERVES TO CARRY THE PARTICLES FORM THE VESSEL, WHEREIN A SUPPLY PIPE FOR COOLING WATER IS CONNECTED TO THE HOOPER AT A LEVEL SPACED BELOW THAT OF THE HIGH-TEMPERATURE WATER IN THE VESSEL, AND IS ADAPTED TO DISCHARGE THE COOLING WATER INTO THE HOPPER ACROSS THE DOWNWARD PATH OF THE PARTICLES THROUGH THE HOPPER, SO THAT THE PARTICLES SINK THROUGH, SUCCESSIVELY, A LAYER OF HIGH-TEMPERATURE WATER AND A LAYER OF COOLING WATER.

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