Thermal conductivity of nickel superalloy MAR-M247

The paper presents the narrow connection between γ’ phase dissolving and values of thermal conductivity. In annealing process the free space among γ’ particles (blocks) changes in certain cycle from fine to rough and back to fine. This is accompanied by decrease and subsequent increase of thermal conductivity as well as the sample density. The results of thermal conductivity coarse are supported by image analysis

Thermal conductivity of nickel superalloy MAR-M247

The paper presents the narrow connection between γ’ phase dissolving and values of thermal conductivity. In annealing process the free space among γ’ particles (blocks) changes in certain cycle from fine to rough and back to fine. This is accompanied by decrease and subsequent increase of thermal conductivity as well as the sample density. The results of thermal conductivity coarse are supported by image analysis

Smanjvanje troškova proizvodnje željeza promjenama parametara vjetra visoke peći

The blast-furnace wind from hot-blast stoves is a significant factor of the blast furnace functioning. The technology was analyzed in which the hot wind from hot-blast stoves is not mixed with the cool wind to a constant wind temperature, but is blown directly into the blast furnace. However, it is necessary to compensate for the changes of the theoretical temperature of burning in blast furnace as a consequence of non-stabilized wind temperature, by changing composition of the wind. This can be done by adding different media into the wind with different results from the operational and economical viewpoints. Essentially, the following types of media are used in blast furnaces: steam, oxygen, substitution fuels, nitrogen, and waste gas.Vjetar visoke peći i peći za zagrijavanje značajno utječe na rad visoke peći. Analizirana je tehnologija kod koje se vrući vjetar iz peći za zagrijavanje ne miješa s hladnim vjetrom do postizanja konstantne temperature nego se direktno upuhuje u visoku peć. Međutim, potrebno je promjenama sastava vjetra kompenzirati promjene teorijske temperature izgaranja u visokoj peći uzrokovane nestabiliziranom temperaturom vjetra. Ovo se može obaviti dodavanjem različitih medija u vjetar uz postizanje različitih rezultata s pogonskog i ekonomskog gledišta. U biti, kod visokih peći se koriste sljedeći mediji: vodena para, kisik, zamjenskog goriva, dušika i otpadnih plinova

Kontrola točke staljivanja na aglomeracijskoj traci

The paper describes the control of burn-through point for sinter on the agglomeration belt. This control is based on mathematical modelling of agglomeration process. The mathematical models and algorithms are derived from basic models of physical and chemical processes of agglomeration belt and they are based on directly and indirectly measured quantities of agglomeration belt. The feed-forward control is based on the quantity of the gas combusted in the ignition furnace and on the quantity and composition of the raw mix. This value is corrected according to the identified burn-through point. Output from the control system is the required value of turbo-exhausters operating speed.U radu se opisuje kontrola točke staljivanja sintera na aglomeracijskoj traci. Ta se kontrola zasniva na matematičkom modeliranju aglomeracijskog procesa. Matematički modeli i algoritmi su izvedeni iz temeljnih modela fizičkih i kemijskih procesa na aglomeracijskoj traci i osnivaju se na izravno i neizravno izmjerenim količinama na aglomeracijskoj traci. Kontrola kretanja naprijed se zasniva na količini plina izgorenog u potpalnoj peći i na količini i sastavu sirove mješavine. Ta veličina se ispravlja prema utvrđenoj točki staljivanja. Izlaz iz kontrolnog sustava je tražena vrijednost operativne brzine turbo-puhala

Smanjvanje troškova proizvodnje željeza promjenama parametara vjetra visoke peći

The blast-furnace wind from hot-blast stoves is a significant factor of the blast furnace functioning. The technology was analyzed in which the hot wind from hot-blast stoves is not mixed with the cool wind to a constant wind temperature, but is blown directly into the blast furnace. However, it is necessary to compensate for the changes of the theoretical temperature of burning in blast furnace as a consequence of non-stabilized wind temperature, by changing composition of the wind. This can be done by adding different media into the wind with different results from the operational and economical viewpoints. Essentially, the following types of media are used in blast furnaces: steam, oxygen, substitution fuels, nitrogen, and waste gas.Vjetar visoke peći i peći za zagrijavanje značajno utječe na rad visoke peći. Analizirana je tehnologija kod koje se vrući vjetar iz peći za zagrijavanje ne miješa s hladnim vjetrom do postizanja konstantne temperature nego se direktno upuhuje u visoku peć. Međutim, potrebno je promjenama sastava vjetra kompenzirati promjene teorijske temperature izgaranja u visokoj peći uzrokovane nestabiliziranom temperaturom vjetra. Ovo se može obaviti dodavanjem različitih medija u vjetar uz postizanje različitih rezultata s pogonskog i ekonomskog gledišta. U biti, kod visokih peći se koriste sljedeći mediji: vodena para, kisik, zamjenskog goriva, dušika i otpadnih plinova

Reduction of costs of iron production by changing parameters of the mixed blast-furnace wind

The blast-furnace wind from hot-blast stoves is a significant factor of the blast furnace functioning. The technology was analyzed in which the hot wind from hot-blast stoves is not mixed with the cool wind to a constant wind temperature, but is blown directly into the blast furnace. However, it is necessary to compensate for the changes of the theoretical temperature of burning in blast furnace as a consequence of non-stabilized wind temperature, by changing composition of the wind. This can be done by adding different media into the wind with different results from the operational and economical viewpoints. Essentially, the following types of media are used in blast furnaces: steam, oxygen, substitution fuels, nitrogen, and waste gas

Thermal conductivity of nickel superalloy MAR-M247

The paper presents the narrow connection between γ’ phase dissolving and values of thermal conductivity. In annealing process the free space among γ’ particles (blocks) changes in certain cycle from fine to rough and back to fine. This is accompanied by decrease and subsequent increase of thermal conductivity as well as the sample density. The results of thermal conductivity coarse are supported by image analysis

Are nonisothermal kinetics fearing historical Newton's cooling law, or are just afraid of inbuilt complications due to undesirable thermal inertia?

Relations between the magnitude of the change of the ratios of crystallization and melting temperature with glass transition temperature, that is Tc/Tg and Tm/Tg, determine the order of the values of relative change of glass stability (GS) parameters dKH/KH, dKW/KW and dKLL/KLL. The linear correlation of new GS parameters FK and FKA which include fragility and reduced glass transition temperature with logRc is a better correlation of KLL. The stretching exponent increases as a linear function of T/Tg in the interval 1≤T/Tg<1•1 for given values of the dynamic fragility parameter m. As result, it follows that the kinetic term in fragility can be neglected. The thermodynamic term, which has a dominant role in fragility can be determined by the expressions for configurational entropy and configurational heat capacity. We compared Sc(T) a function of temperature dependence of configurational entropy which was obtained by Sipp et al and ScVFT (T) a function proposed by Yue. Both Sc(T) and ScVFT (T) have the same temperature dependence and almost overlap. Therefore, using either Sc(T) or ScVFT (T) we will get the same value of fragility index. From the dependence of lnSc(T) versus lnT it is possible to successfully predict the relations between the values of m for different glass formers