SE187982C1

SE187982C1 -

Info

Publication number: SE187982C1
Authority: SE
Publication date: 1963-01-01

Description

Uppfinnare: F B H van Bergen och C G Badcock Prioritet begard frem den 29 maj 1956 och den 5 mars 1957 (Storbritannien) Foreliggande uppfinning hanfor sig till inforande av olika amnen i bad av small metall, exempelvis skankar eller blandare innehallande smalt gjutjarn. Inventors: F B H van Bergen and C G Badcock Priority requested on 29 May 1956 and 5 March 1957 (Great Britain) The present invention relates to the introduction of various substances into small metal baths, for example shanks or mixers containing narrow cast iron.

Vid behandling av smalt gjutjarn for uppnaende av forbattrade hallfasthetsegenskaper tillsattas olika amnen i ugnen eller skanken. Resultatet beror harvid pa om man kan reglera tillsatserna noggrant, sa att man far onskat resultat, och de onskade egenskaperna hallas Mom snava granser. Detta har alltid varit svart att uppna i praktiken pa grund av den vaxlande upptagningen av de tillsatta amnena i gjutjarnet. When treating narrow cast iron to achieve improved hall strength properties, various substances are added to the furnace or shank. The result then depends on whether you can regulate the additives carefully, so that you get the desired result, and the desired properties are kept Mom tight boundaries. This has always been difficult to achieve in practice due to the alternating uptake of the added substances into the cast iron.

Det hr valkant, att manga legeringar och tillsatsamnen delvis ga farlorade genom oxidation, da de tillforas pa ytan av smalt metall pa vanligt salt, varigenom effekten fOrsamras, det blir nOdvandigt att tillsatta storre mangder behandlingsmedel, det bildas star mangd slagg och kostnaderna okas. Harigenom blir det aven svart att reglera reaktionen, som blir osaker till sin verkan. It is an option that many alloys and additives are partially lost by oxidation, as they are applied to the surface of molten metal on ordinary salt, whereby the effect is reduced, it becomes necessary to add larger amounts of treatment agent, a large amount of slag is formed and costs are increased. As a result, it also becomes black to regulate the reaction, which becomes uncertain in its effect.

Det har salunda i praktiken visat sig, att kiselforeningar och karbider av jordalkalimetaller aro svara att inf6ra i smalt gjutjarn pa grand av bildningen av en ytbelaggning av oxid vid upphettning i narvaro av luft. Man har forsi5kt manga olika utvagar for undanrojande av denna svarighet. I den brittiska patentskriften 727 707 beskrives sMunda ett salt att avhjalpa denna olagenhet. Alla hittillsvarande metoder innebara emellertid fOrbrukning av storre mangder av amnena och aro svara att genomfora. Thus, it has been found in practice that silicon compounds and carbides of alkaline earth metals are likely to introduce into narrow cast iron due to the formation of a surface coating of oxide when heated in the presence of air. Many different choices have been made to eliminate this responsibility. British Patent Specification 727 707 discloses a salt to remedy this illegality. All methods hitherto involved, however, involved the consumption of large quantities of the substances and were difficult to implement.

F8religgande uppfinning hanfor sig nu till en anordning for infOrande av pulver- eller kornformiga amnen i ett bad av smalt metall. The present invention now relates to an apparatus for introducing powdery or granular substances into a narrow metal bath.

Denna anordning omfattar flera behallare for de amnen, som skola inforas, medel for att mata ut en separat reglerbar mangd amne fran var och en av behallarna till en gemensam mottagningsbehallare, medel med hjalp av vilka en reglerad mangd tryckgas kan inforas i behallaren och utmatningsmedlet, samt en ledning fran mottagningsbehallaren anordnad att inf8ras under ytan pa den smalta me: tallen i badet. This device comprises several containers for the blanks to be introduced, means for discharging a separately controllable amount of blanks from each of the containers to a common receiving container, means by means of which a regulated amount of compressed gas can be introduced into the container and the dispensing means, and a conduit from the receiving container arranged to be inserted below the surface of the narrow metal in the bath.

Enligt en annan utforingsform av uppfinningen omfattar en anordning for inmatning av korn- eller pulverformiga aninen i ett had av smalt metall flera behallare fOr de amnen; som skola inmatas, en tryckkammare, flera doseringsanordningar, som aro placerade i kammaren och anordnade att var och en taga emot amnet fran en av behallarna och att mata fram en avmatt mangd amne fran behMlaren till en gemensam mottagningsbehallare, medel for installning av var och en av ma:tar, anordningarna oberoende av de andra, sa att man kan reglera den fran varje behallare frammatade mangden, medel genom vilka tryckgas kan inforas med reglerbar hastighet i behallarna och i tryckkammaren, samt en led ning, som gar fran mottagningsbehallaren och hr anordnad att inforas under ytan pa den smalta metallen i badet. According to another embodiment of the invention, a device for feeding the granular or powdered anine into a narrow metal cap comprises several containers for the substances; to be fed, a pressure chamber, several dosing devices, which are placed in the chamber and arranged to each receive the item from one of the containers and to supply a dispensed amount of item from the container to a common receiving container, means for installing each of means, the devices independently of the others, so that the quantity fed from each container can be regulated, by means of which pressurized gas can be introduced at an adjustable speed into the containers and into the pressure chamber, and a line, which leaves the receiving container and arranged here. to be inserted below the surface of the molten metal in the bath.

Uppfinningen omfattar aven ett forfarande for infOrande av korn- eller pulverformiga amen i ett bad av smalt metall, varvid amnena under gastryck ledas till en gemensam mottagningsbehallare med reglerad tillfarselhastighet, vilken kan regleras f6r vane amne, varjamte gas inforas i den gemensamma motL tagningsbehallaren med reglerbar och install - bar stromningshastighet, sh att man kan upp Dupl. kl. 18 b: 2 2-- — ratthalla varje onskat forhallande mellan am-net och gasen, varjam.te amnena av den strommande gasen foras fran mottagningsbehallaren genom en ledning och inblasas under ytan pa den smdlta metallen. The invention also comprises a process for introducing granular or powdered amen in a bath of narrow metal, wherein the amines under gas pressure are led to a common receiving container with a controlled supply rate, which can be controlled for a conventional item, and gas is introduced into the common receiving container with controllable container. and install - bar flow rate, sh that you can up Dupl. at 18 b: 2 2-- - steering wheel holds any desired relationship between the furnace and the gas, each of which the substances of the flowing gas are passed from the receiving tank through a conduit and blown under the surface of the molten metal.

Om tillsatsamnena inforas i smalt gjutjarn med inmatningsanordningen enligt foreliggande uppfinning, är det mojligt all uppna starkt forbattrad effektivitet och att darigenom bibringa gjutjdrnet speciella egenskaper med en noggrannhet, som icke kan uppnas elj est. Inmatningsanordningen gor det icke endast mojligt att uppna forbattrad reaktionseffektivitet utan ben att utba exakt kontroll over den mangd legering eller reagens, som infores i den smalta metallen. Denna kombination av effektiv reaktion och exakt reglering av materialmangden är av storsta betydelse for uppnaende av den noggranna metallurgiska kontroll, som är nodvandig for effektiv drift. If the additives are introduced into narrow cast iron with the feed device according to the present invention, it is possible to achieve greatly improved efficiency and thereby to impart to the cast iron special properties with an accuracy which cannot be achieved otherwise. The feed device not only makes it possible to achieve improved reaction efficiency without bones to provide precise control over the amount of alloy or reagent introduced into the molten metal. This combination of efficient reaction and precise control of the amount of material is of the utmost importance for achieving the precise metallurgical control, which is necessary for efficient operation.

Uppfinningen kommer i det foljande att beskrivas narmare med hanvisning till bifogade ritning, vilken som exempel visar nagra utforingsformer. Fig. 1 är en vy framifran av en anordning konstruerad enligt foreliggande uppfinning. Fig. 2 är en sidovy. Fig. 3 är en schematisk planvy. Fig. 4 visar en detalj i en modifikation. The invention will be described in more detail below with reference to the accompanying drawing, which shows, by way of example, some embodiments. Fig. 1 is a front view of a device constructed in accordance with the present invention. Fig. 2 is a side view. Fig. 3 is a schematic plan view. Fig. 4 shows a detail in a modification.

Den pa ritningen visade anordningen omfattar tre behallare, 1, la och lb for det eller de amnen, som skola infOras i den smalta metallen. De tre behMlarna lianas under tryck medelSt tryckgas, lampligen kvavgas, som tillfores frau en icke visad källa medelst en ledning 2, som kr ansluten till byre anden av vardera behallaren. Ett langstrackt ftinster 3 av genomskinligt material Or lampligen anordnat pa framsidan av varje behallare, sa att man kan observera behallarens fyllnadsgrad. The device shown in the drawing comprises three containers, 1, 1a and 1b for the substance or substances to be introduced into the molten metal. The three containers are pressurized by means of compressed gas, suitably nitrogen gas, which is supplied from a source (not shown) by means of a line 2, which is connected to the byre spirit of each container. An elongated window 3 of transparent material is suitably arranged on the front of each container, so that the degree of filling of the container can be observed.

Vid nedre linden stracker sig varje behMlare in i en utmatningsanordning, omfattande en tryckkammare 4, som genom en grenledning 2a Or ansluten till ledningen 2, sa att kammaren sates under tryck med samma tryckgas som behallama. Amnena ledas genom ett utlopp vid nedre linden av varje behallare till en elektriskt driven matare 5 med vibrerande OW. Denna matare verkar som doseringsanordning och matar ut en given mangd per tidsenhet. Matningshastigheten kan regleras medelst en reostat 6, eller nagot annat don, som Or installbart Iran en utvandig, icke visad instrumenttavla. Mataren 5 matar amnena fran varje behallare till en gemensam mottagningsbehallare 7, frau vilken de av gasen ledas genom en ledning 8, som overgar Si ett eldfast rOr 9, som kan placeras i badet av smolt metall i en icke visad skank. Ett lock 10 Or anordnat for skydd av anordningen mot vdrmet frail skanken. Tryckkammaren 4 har ett fOnster 11 for overvakning av matningen. En utloppsventil 12 är anordnad i roret 8 for reglering av fl6det av gas och amnen till den smalta metallen. En ma nometer 13 Or kopplad till tryckkammaren 4, sO att man kan overvaka trycket i kammaren och behallarna. En strOmningsmdtare 14 for gasen Or ansluten till inloppsledningen 2 eller till nagot annat lampligt stalle for angivande och underlattande av kontrollen av den gasvolym, som ledes in i den smalta metallen. At the lower winding, each tank extends into a discharge device, comprising a pressure chamber 4, which is connected to the line 2 by a branch line 2a Or, so that the chamber is pressurized with the same pressure gas as the tanks. The blanks are led through an outlet at the lower winding of each container to an electrically driven feeder 5 with vibrating OW. This feeder acts as a dosing device and dispenses a given amount per unit time. The feed rate can be controlled by means of a rheostat 6, or some other device, such as Or installbart Iran an external, not shown instrument panel. The feeder 5 feeds the items from each container to a common receiving container 7, from which they are led by the gas through a line 8, which exits Si a refractory tube 9, which can be placed in the bath of molten metal in a shank (not shown). A lid 10 Or arranged for protection of the device against the heat from the shank. The pressure chamber 4 has a window 11 for monitoring the supply. An outlet valve 12 is provided in the tube 8 for regulating the flow of gas and the substances to the molten metal. A manometer 13 Or connected to the pressure chamber 4, so that you can monitor the pressure in the chamber and the containers. A flow meter 14 for the gas Or connected to the inlet line 2 or to some other suitable stable for indicating and facilitating the control of the volume of gas which is led into the molten metal.

Det hela Or anordnat pa ben 15 och kan placeras p0 ldmpligt aystand fran ugnen eller skanken under anvandning av ett ror 8 med lamplig langd. The whole Or is arranged on legs 15 and can be placed at a suitable distance from the oven or shank using a tube 8 of suitable length.

Det at icke nodvandigt att doseringsanordningarna utgoras av matare 5 av vibrerande typ, eftersom man kan anvanda nagon annan anordning, som medger exakt reglering av matningen. Sasom visas i fig. 4 kan materialet matas Iran behallarna genom en roterande kugghjulsmatare 16. It is not necessary for the dosing devices to be made of feeders of the vibrating type, since any other device can be used which allows precise control of the feeding. As shown in Fig. 4, the material can be fed to the Iran containers through a rotary gear feeder 16.

Under driften sdttas behallarna 1 och kammaren 4 under tryck med hjalp av kvavgas eller nagon annan lamplig gas, som tillfores under tryck genom roret 2. Ett tryck av 0,5 at anvandes normalt, och det Or viktigt, att trycket Mlles konstant, sa att man far ett likformigt forhallande material till gas. F6re igangsattningen fyllas behallarna 1, varefter dessa och kammaren 4 stangas och sattas under tryck. Locket 10 placeras i sitt Edge, varefter utmatningsventilen 12 oppnas delvis, sa att gasen borjar att stromma ut. Det eldfasta roret 9 nedfOres sedan langsamt i den smalta metallen i skanken genom ett hal i locket 10 och lases i sitt lOge. Ventilen 12 oppnas sedan till sitt driftldge, varefter man kopplar in doseringsanordningarna 5 eller 16, som Oro installda pa den onskade matningshastigheten. Sedan metallen har behandlats under erforderlig tid, kopplas doseringsanordningarna 5 eller 16 ur, strypes ventilen 12, drages det eldfasta roret 9 upp och stanges ventilen 12. During operation, the containers 1 and the chamber 4 are pressurized with the aid of nitrogen gas or any other suitable gas which is supplied under pressure through the tube 2. A pressure of 0.5 is normally used, and it is important that the pressure is constant, so that a uniformly proportioning material is obtained for gas. Before starting, the containers 1 are filled, after which these and the chamber 4 are closed and pressurized. The lid 10 is placed in its Edge, after which the discharge valve 12 is partially opened, so that the gas begins to flow out. The refractory tube 9 is then slowly lowered into the narrow metal of the shank through a hall in the lid 10 and read in its lodge. The valve 12 is then opened to its operating day, after which the dosing devices 5 or 16 are connected, which are set at the desired feed rate. After the metal has been treated for the required time, the dosing devices 5 or 16 are disconnected, the valve 12 is throttled, the refractory tube 9 is pulled up and the valve 12 is closed.

Mataranordningen Or kalibrerad att halla en sadan utmatningshastighet for det material, som skall regleras, att en reglerbar mangd av material avges per tidsenhet. Det onskade materialflodet och gastrycket beraknas genom kalibrering av anordningen i luft under tilldgg av det tryck, som erfordras fOr att Overvinna det ferrostatiska trycket Iran den smalta metallen i badet. The feed device is calibrated to maintain such a discharge rate for the material to be regulated that a controllable amount of material is delivered per unit time. The desired material flow and gas pressure are calculated by calibrating the device in air while applying the pressure required to overcome the ferrostatic pressure in the molten metal in the bath.

En fordel med mataranordningen enligt föreliggande uppfinning Or, att inmatningen och regleringen av tillflodet av behandlingsmaterial regleras med ett enda gastryck i stallet for med de olika gastryck, som vanligen anvandas och som innebdra noggrann avsiagfling av trycket p0 tillsatsmaterialen mot inblasningstrycket i utmatningsroret. Harigenom fOrenklas i hOg grad regleringen av fOrhallandet tillsatsmaterial till gas, vilket Or sa viktigt vid reglering av metallbehandlingen. An advantage of the supply device according to the present invention is that the supply and control of the supply of treatment material is regulated with a single gas pressure instead of with the different gas pressures which are commonly used and which involve accurate sensing of the pressure of the additives against the supply pressure in the discharge pipe. This greatly simplifies the regulation of the ratio of additives to gas, which is so important in regulating the metal treatment.

En annan fordel med foreliggande uppfinning Or, att man kan reglera tillforseln av behandlingsmaterialet exakt. Normalt upp&Oda svarigheter vid frammatning av en for- — 487 982 —3 utbestamd mangd material med. given tillforselhastighet med hjalp av en skillnad mellan gastryck. I anordningen enligt uppfinningen regleras gasflodet och materialtillforseln oberoen.de av varandra, sa att det blir mojligt att uppria ett bestamt forhallande material till gas och en bestamd strOmningshastighet. Another advantage of the present invention is that the supply of the treatment material can be precisely controlled. Normally up & Oda responsibilities when feeding a pre- - 487 982 —3 determined amount of material with. given supply speed by means of a difference between gas pressure. In the device according to the invention, the gas flow and the material supply are regulated independently of each other, so that it becomes possible to raise a certain relative material to gas and a certain flow rate.

En annan fordel med foreliggande uppfinning är, att den gör det mojligt att infora till- satsmaterialen i den smalta metallen anting- en separat eller blandade i onskade proportioner. For detta kan man installa doseringsan- ordningarna 5 eller 16 under flagon eller alla behallarna 1 pa samma eller olika matningshastigheter alltefter forhallandena. Detta in- nebar ett avsevart framsteg betraffande an- passbarheten och effektiviteten, emedan det harigenom blir mojligt att samtidigt tillfora olika tillsatsmaterial och att tillfora varje Onskad blandning av materialen alltefter behovet for de metallbad, som skall behandlas, och detta utan avbrott i tillforseln av material En spcciell fordel med mataranordningen enligt foreliggande uppfinning är den mojlig- het, som den erbjuder for exakt reglering vid framstallning av kvalitetsgjutjarn. I den brittiska patentskriften 590 344 beskrives ett for- farande for reglering av gjutjarnets egenska- per genom bestamning av dess konstitutionella karbidkilvarde och grafitisering av smattan till ett forutbestarnt varde alltefter gjutgod- sets onskade egenskaper och dess sektionstjocklek. Med mataranordnignen enligt fore- liggande uppfinning uppnas med stone sakerhet, att tillsatsmaterialen reagera effektivt med den smalta metallen, sa. 'att man far en noggrannare kontroll Over behandlingen av denna. Another advantage of the present invention is that it makes it possible to introduce the filler materials into the molten metal either separately or mixed in desired proportions. For this, the dosing devices 5 or 16 can be installed under the flake or all the containers 1 at the same or different feed speeds, depending on the conditions. This entailed considerable progress in terms of adaptability and efficiency, as it thereby made it possible to simultaneously supply different additive materials and to supply each desired mixture of materials according to the need for the metal baths to be treated, and this without interruption in the supply of materials. A particular advantage of the feeder device according to the present invention is the possibility which it offers for precise control in the production of quality cast iron. British Patent Specification 590 344 describes a procedure for regulating the properties of cast iron by determining its constitutional carbide wedge value and graphitizing the mat to a predetermined value according to the desired properties of the cast iron and its section thickness. With the feeder device according to the present invention, it is achieved with stone certainty that the additive materials react effectively with the molten metal, said. 'that one gets a more accurate control Over the treatment of this.

Foreliggande uppfinning innebar en f orbattrad metod for genomforande av det satt for framstallning av gjutjarn, som beskrives i den brittiska patentskriften 742 168. Salunda inmatas kiselforeningar och fluorider av jordalkalimetaller i mottagarbehallaren med exakt reglerad hastighet och inforas under ytan pa den smalta metallen genom ett ror, sá att man far effektiv reaktion med ett minimum av behandlingsmaterial, och den smalta metallens konstitutionella karbidvarde minskas i anpassning efter det karbidvarde, som erfordras pa grund av gjutgodsets sektion och de onskade fysikaliska egenskaperna. The present invention provided an improved method of carrying out the cast iron production method described in British Pat. No. 742,168. , so that an efficient reaction is obtained with a minimum of treatment material, and the constitutional carbide value of the molten metal is reduced in adaptation to the carbide value required due to the casting section and the desired physical properties.

En ytterligare fordel med foreliggande uppfinning är, att specialbehandlingar for avlagsnande av fororeningar i smalt gjutjarn aro latta att genomfora. En gjutjarnssmalta innehallande 0,138 % svavel behandlades salunda med kalciumkarbid tillford genom en mataranordning enligt foreliggande uppfinning, varvid 2,5 % kalciumkarbidpulver tillf8rdes genom inblasning under 3 min. Efter behandlingen visade det sig, att svavelhalten hade sjunkit till 0,006 %. Vid en annan avsvavling behandlades gjutjarn innehallande 0,117 % svavel med 1,8 % kalcimnkarbid under 5 mm, varvid svavelb.alten efter behandlingen blev 0,006 %. En annan behandling av gjutjarn med 0,028 % svavel genom inblasning av 2 % kalciumkarbid under 2 min gay en slutlig svavelhalt av 0,003 %. A further advantage of the present invention is that special treatments for the removal of contaminants in narrow cast iron are easy to carry out. A cast iron malt containing 0.138% sulfur was thus treated with calcium carbide fed through a feeder according to the present invention, 2.5% calcium carbide powder being added by blowing for 3 minutes. After the treatment, it was found that the sulfur content had dropped to 0.006%. In another desulfurization, cast iron containing 0.117% sulfur was treated with 1.8% calcium carbide below 5 mm, the sulfur content after treatment being 0.006%. Another treatment of cast iron with 0.028% sulfur by blowing 2% calcium carbide for 2 minutes gay a final sulfur content of 0.003%.

Ett annat .exempel utgor en inblasningsbehandling med mataranordningen enligt foreliggande uppfinning for forandring av grafitens form, sá att grafiten far nodular struktur och h8g hallfasthet uppnas. Pa senare tid ha flera metoder foreslagits fOr att overfora grafiten frail fjallig form till kulor eller sfarer. Tvâ saclana forfaranden beskrivas i de brittiska patentskrifterna 659 928 och 727 707, en7. ligt vilka grafitens form andras genom be-handling med olika material, sasom jordkalimetaller eller kiselforeningar eller karbider av sadana. Det har visat sig, att det forfarande som beskrives i dessa patentskrifter, kan genomfOras effektivare med mataranordningen enligt foreliggande uppfinning och med noggrannare reglering. Another example is a blowing treatment with the feeder device according to the present invention for changing the shape of the graphite, so that the graphite has a nodular structure and a high half-strength is achieved. Recently, several methods have been proposed for transferring the graphite from the scaly form to spheres or spheres. Two saclana processes are described in British Patents 659,928 and 727,707, en7. which the shape of the graphite changes by treatment with various materials, such as earth potassium metals or silicon compounds or carbides of such. It has been found that the process described in these patents can be carried out more efficiently with the feeding device according to the present invention and with more precise control.

Vid det forfarande, som beskrives I den brittiska patentskriften 649 928 infOrdes sa, lunda det metakarbidstabiliserande amnet i den smalta metallen med reglerad mangd och stromningshastighet frau en av behallarna, sá att smaltan vid gjutning far hagelsatt till helvit struktur. Ett grafitiseringsmedel tillf 0- res sedan fran en annan behallare i en mangd och med en hastighet, som Or installd for att ge det kilvarde, som erfordras I forhallande till gjutningssektionen. Denna behandling genomfordes med gjutjarn framstallt i en kupolugn med surt foder och med foljande sammansattning Totalt kol3,66 Kisel1,52 Mangan0,46 Svavel0,112 Det smalta jarnet tappades i en skank och avsvavlades fOrst, varefter det behandlades ph det satt for framstallning av nodulart jam, som beskrives i den brittiska patentskriften 659 928.Det bildade jarnet analys och egenskaper: hade foljande Totalt kol 3,37 Kisel 2,8 Mangan 0,42 Svavel 0,002 Brottgrans 70,1 kpinam2 Forlangning (gjutet) 4,4% Det ma understrykas, att den speciella fordelen med fOreliggande uppfinning är den exakta reglering, som den mojliggor vid tillverkning av jam med speciella egenskaper, aven om jarnet har framstallts genom vanlig sraaltning i en. kupolugn med surt foder. Genom detta forfarande kunna kostnaderna sankas avsevart, emedan man icke behtiver smal- 4— — ta i specialugnar, som elektriska ugnar eller kupolugnar med basiskt foder. Vidare behover man icke smalta stora satser i ugnen, dá endast smarre mangder jam erfordras for det gjutgods som skall framstallas. In the process described in British Pat. A graphitizer is then supplied from another container in a quantity and at a speed which is installed to give the wedge value required in relation to the casting section. This treatment was carried out with cast iron made in a dome furnace with acidic lining and with the following composition Total carbon3,66 Silicon1.52 Manganese0.46 Sulfur0.112 jam, as described in British Pat. It is emphasized that the particular advantage of the present invention is the precise control which it makes possible in the manufacture of jams with special properties, even if the yarn has been produced by ordinary milling in one. dome stove with acidic feed. By this procedure the costs can be reduced considerably, since it is not necessary to narrow in special furnaces, such as electric furnaces or dome furnaces with basic lining. Furthermore, it is not necessary to melt large batches in the furnace, as only small amounts of jam are required for the casting to be produced.

En annan fordel med foreliggande uppfinning är, att man icke behover uppsatta beskickningar med olika sammansattning i kupolugnen. Det har tidigare varit nodvandigt att vid gjutning andra sammansattningen av den beskickning, som uppsattes i ugnen, alltefter de olika typer gjutgods, som skola framstallas. I ett gjuteri kan man salunda pa en och samma dag behova olika typer av gjutjarn fran mjukt gjutjarn med lag hallfasthet upp till tatt gjutjarn med hog hallfasthet. De olika blandningarna for framstallning av mjukt eller hart gjutjam ha tidigare mast innehalla varierande mangder tackjarn, kol, koks och liknande, vilket har inneburit en invecklad ugnsdrift flir att materialen skulle beskickas i exakta proportioner. Vidare har det alltid varit svart att halla isar de olika typerna small metall, da de ha kommit fram till kupolugnens utslagshal och att anvanda blandningarna vid Overgang fran en typ till en annan. Man behover nu endast framstalla en typ av gjutjarn, av vilket man genom be-handling i skank med mataranordningen enligt foreliggande uppfinning, kan erhalla varje erforderlig typ av gjutjarn. Another advantage of the present invention is that one does not need set up missions of different composition in the dome furnace. It has previously been necessary, when casting, for the second composition of the charge placed in the furnace, according to the different types of castings to be produced. In a foundry, one can thus in one and the same day need different types of cast iron from soft cast iron with low half-strength up to cast cast iron with high half-strength. The various mixtures for the production of soft or hard cast iron have previously had to contain varying amounts of pig iron, coal, coke and the like, which has meant an complicated kiln operation so that the materials would be loaded in exact proportions. Furthermore, it has always been black to ice the different types of small metal, as they have reached the dome of the dome furnace and to use the mixtures at Transition from one type to another. It is now only necessary to produce one type of cast iron, from which, by treatment in shank with the feeding device according to the present invention, one can obtain any required type of cast iron.

Kupolugnen kan salunda drivas med en standardbeskiclming, som efter smaltningen ger ett gjutjarn med foljande sammansattning och egenskaper: Totalt kol2,9 % Kisel1,5 " Mangan0,8 " Brottsgrans 37,8 kp/mm2 Brinellhardhet vid 25,4 mm tjocklek 2 Ur detta material kan man nu med mataranordning enligt foreliggande uppfinning erhalla varje typ av gjutjarn ned till det mjukaste gjutjarn, som kan behovas. Man kan salunda framstalla en mellankvalitet och med mataranordningen enligt uppfinningen samtidigt satta kol och ferrokisel till den smalta metallen i skanken, sa all man far en brottgrans av 28,4 kp/mm2 och en brinellhardhet av 200. Pa grund av franvaron av oxidering och pa grund av den hoga reaktivitet, som uppnas, absorberas erforderlig mangd kol oeh kisel i metallen. The dome furnace can thus be operated with a standard coating, which after melting gives a cast iron with the following composition and properties: Total carbon2,9% Silicon1,5 "Manganese0,8" Fracture margin 37.8 kp / mm2 Brinell hardness at 25.4 mm thickness 2 From this material, one can now with any feeding device according to the present invention obtain any type of cast iron down to the softest cast iron that may be needed. It is thus possible to produce an intermediate quality and with the feeder device according to the invention simultaneously added carbon and ferro-silicon to the molten metal in the shank, so that all have a breaking limit of 28.4 kp / mm2 and a brinell hardness of 200. Due to the absence of oxidation and pa Due to the high reactivity achieved, the required amount of carbon and silicon is absorbed in the metal.

Av den ursprungliga metallen iir det aven mojligt att framstalla ett mjukt gjutjarn enligt foljande specifikation: Totalt kol3,5 % Kis el2,5 " Mangan0,8 " Brottgrans 18,9 kp/mm2 Brinellhardhet vid 25,4 mm tjocklek 1 Detta resultat kan ocksa latt upnas genom reglerad tillforsel av kol och ferrokisel med mataranordningen enligt uppfinningen. Det är aven majligt att framstalla ett hart, slitstarkt gjutjarn av den ursprungliga metallen genom inblasning av ferrolegeringar, sasom ferrokrom, sä att man far en brinellhardhet Over 500. From the original metal it is also possible to produce a soft cast iron according to the following specification: Total carbon3,5% Kis el2,5 "Manganese0,8" Fracture 18.9 kp / mm2 Brinell hardness at 25.4 mm thickness 1 This result can also can be opened by controlled supply of carbon and ferro-silicon with the feeder device according to the invention. It is also possible to produce a hard, durable cast iron from the original metal by blowing in ferro-alloys, such as ferrochrome, so that a brinell hardness of over 500 is obtained.

De ovan beskrivna regleringsforfarandena Ora det mojligt att astadkomma en reglerad framstallning av varje typ av gjutjarn pa ett satt, som icke har varit mojligt tidigare. Bland de uppnadda fordelarna kunna namnas av behovet av uppsattning av olika blandningar pa ugnen, hog regleringsnoggrannhet, minskade kostnader pa grund av anvandning av billigare ramaterial och mojligheten att framstalla ett start antal olika me-taller i de sma mangder, som erfordras for olika typer av gjutgods. The control methods described above make it possible to achieve a controlled production of each type of cast iron in a manner which has not been possible before. Among the advantages obtained can be mentioned the need to set up different mixtures on the furnace, high control accuracy, reduced costs due to the use of cheaper raw materials and the possibility to produce a starting number of different metals in the small quantities required for different types of castings.

De ovan beskrivna utforingsformerna kunna modifieras, utan att man argir overskrider uppfinningens ram. The embodiments described above can be modified without arguably exceeding the scope of the invention.

Claims

Patent claim:

Device for feeding powdery or granular substances into a bath of narrow metal, designed by several containers for the substances to be fed, means for feeding a separately controllable amount of each substance from each of the containers into a common receiving containers, by means of which a controlled amount of gas under pressure can be introduced into the containers and into the feeding devices, as well as a conduit which leaves the receiving container and is arranged to be inserted below the surface of the narrow metal in the bath.

Device according to claim 1, characterized by a pressure chamber, several dosing devices, which Oro placed in the chamber and each Or arranged to receive an item Iran one of the containers and to advance a dispensed amount of the item from the container to a common receiving container, and devices for separate installation of each dosing device independently of the others for controlling the amount of substance supplied from each container.

3. Device according to claim 2, characterized in that the containers with their lower spirit open inside the chamber above the dosing devices and that the receiving container extends out to the bottom of the chamber of Iran, that a line Or is arranged to direct pressurized gas from each of the containers and that a branch line from the said pipe is arranged to lead compressed gas to the chamber.

4. Device according to patent claim 2 or 3, characterized in that the dosing devices are of the type with vibrating shell - - and each 5 is arranged to supply a given amount of substance per unit time.

5. The method of feeding powder or granular blanks into a small metal bath using the device according to claim 1-4, characterized in that the blanks are introduced under the influence of compressed gas into a common receiving container with a supply speed which can be installed for habit gas, that gas is introduced into the common receiving container at an adjustable and controllable flow rate, so that one can maintain the habit in a limited relationship between the particles and the gas, and that the particles of the gas stream are passed with the frail receiving container through a conduit and inserted under the narrow metal surface. Cited publications: U.S. Patent Nos. 1,842,409.