DE1303081B - - Google Patents

Description

1 2

The invention relates to a method for the formation of a flame, which because of their

Cast iron smelting in a cupola furnace. The _{increase in the CO 2} and water vapor content is increased

driving allows the production of a wide variety of radiation capacities and thereby a

Castings in mold casting. In particular, it is supposed to bring about better heat exchange. One stronger

machinable castings with changing prostitutes- 5 reducing atmosphere or improving the

sions are produced, with high-quality properties of the cast iron being made possible by this

shafts can be achieved very precisely as required. Procedure not achieved.

According to the method, cast iron can be used with its own. In a known cupola furnace is in the lowest

manufacture shafts through which a cyclone combustion chamber is provided for certain parts of the furnace,

Twists in place of the previously necessary medium hario in the combustion air, additional air and fuels

ten steels or alloys can be used. is blown in. These measures are without

When casting with high-quality properties, the strength of the reducing atmospheric pressure has so far resulted in numerous difficulties, ins- sphere. As with all known injection processes, especially in the production of castings with, only an improvement in the thermal strength of changing thickness is achieved. The cast iron obtained through the well-known economy and the replacement of the expensive foundry coke process is intended for processing by cheaper fuels,
processing difficult because the homogeneity and tightness It has now been found that the disadvantages of being uneven. The mediocre wear and tear known processes are avoided as soon as the properties have their cause in the heterogeneous melting process in the presence of ketenes and in the defects of the castability of the 20 will.

Cast iron, which is therefore more sensitive to the subject matter of the invention, a method for Is cracks and blisters. Numerous smelting of cast iron in cupola furnaces have already been attempted to improve the quality of the casting by means of an atmosphere with additional heating that leads to it. The composition is characterized by the fact that it is processed for example through the addition of expensive alloys as the combustion or melting zone acetone as ketene elements, such as chromium, nickel, molybdenum, etc. Even-forming substance, gaseous or liquid, continuously if an attempt has been made, the casting is introduced by special measure. This will remove the irregularities took part in the management and loading of the cupola, which eliminated the disadvantages of the known to improve ovens. One has z. B. the constant method or the errors of the products obtained Keep the successive batches very carefully.

carefully monitored. However, all of these attempts have been made according to one embodiment of the invention

a mixture of acetone and benzene in the mixture

mentioned defects can lead. Ratio of 10:90 to 90:10 introduced.

After a critical study of the known processes, the total sulfur consumption, the numerous investigations and the content can be significantly higher without the risk of suggested improvements for melting castings - a reverse white solidification. If iron has now been found that, after the start-up, the level of the smelting processes in the cupola furnaces changes in all-zone or the percentage of fuel changes in the common too strongly oxidizing atmosphere of the charge or the amount of ketene increases, can prevail and that the reduction goes too slowly from one to 40 for the total carbon and for the graphite plates. These phenomena cause different curves to be obtained. This shows, therefore, deterioration of the metal, with certain elements, that one can regulate the primary graphitization,
th burn losses and other elements, such as the fully controllable primary graphitization z. B. the phosphorus, often harmful cohesion remains with constant total carbon at conclusions or concentrations. Furthermore, work according to the invention always occurs more strongly than in the case of inferences of gases and impurities. all known melting processes. It was

It is also known that it is difficult to find that the method even at very little

reducing furnace cycle with regard to CO. Total carbon is suitable. The procedure is

All previously proposed means for regulating the even with a load of up to 100% steel

Oven corridor or the oven guide and to the bottom 50 can be carried out.

suppressing the above disadvantages are empirical. The process can be carried out in known cupola furnaces

and do not guarantee the constancy of the processes that are carried out with injection nozzles.

and the products obtained. are armed. The injectors can be in the

It is known to cast iron in a strongly reducing tuyere level or between tuyere level and

Melting atmosphere. In the known melting zone or directly at the tuyeres

however, a hot blast cupola furnace must be installed.

are turned, and the slag guide or it can, if desired, in a per se known

Composition of the slag must be blown in strictly oxygen-enriched air

be trolled. The latter as well as the generation of the will.

A hot breeze from 530 to 570 ° C requires a 60 The process can be carried out continuously increased workload and increased costs. Loading. Here, identical batches can be used for special Properties of cast iron will be abandoned with the aim of identical tapping. It this procedure is not achieved. can also be used without interrupting the furnace

It is also known that the temperature in cupola operation can be used for different batches one after the other furnace by giving up hydrocarbons, which sequentially pollute, how oil, tar, masut, naphtha residues and the like, different types of cast iron are melted, introduces in the nozzle level or below. According to each of which the respective batches submitted These additives are intended to correspond to one of these processes.

Claims (2)

3 4 To start a cupola one can be cash and that it is possible to use moldings start from a conventional cold oven and make it flawless with thickness differences of 4 to 240 mm according to the procedure up to the incapacity to operate. The results will be surprising keep, with the batches not only achieved with the usual genera, depending on what is desired. Product can be changed. However, an addition of 10% of pig iron is sufficient. also start from a known type of behavior. There is also one that cannot be overlooked driven melting process and, depending on the intentions, to see economic advantage, During the operation of the furnace on the method The casting obtained according to the invention can be a pass over the invention and vice versa be from casting with lamellar graphite or also The method of the invention relies on a conventional starting material for steel production. One after that skip driving. Process of the invention is cast iron made The method of the invention is not restricted to processing in further processing,
working of all known for the production of castings Suitable for loads. In relation to the patent claims, it allows:
known methods the production of cast 15 pieces with better mechanical properties. 1. Process for melting cast iron The castings produced according to the process are added to the cupola furnace in a reducing atmosphere a tensile strength of up to 50kg / mm ² , an additional heating, thus marked Shear strength of 50 to 55 kg / mm ² , a penetration that one in the combustion or bend of about 10 mm with 1500 kg load of a 20 melting zone acetone as a ketene-forming substance continuously introduces raw normal test specimen with a diameter of 22 mm and gaseous or liquid, a Brinell hardness up to 225, even up to 285. 2. The method according to claim 1, characterized A further advantage of the process is to be noted that a mixture of acetone and think that the casts produced have an excellent benzene mixture ratio of 10:90 to dense, fine structure, very easy to manufacture 25 90:10 is introduced.