Detail publikace

Influence of Water Temperature on The Cooling Intensity of Mist Nozzles in Continuous Casting

Originální název

Influence of Water Temperature on The Cooling Intensity of Mist Nozzles in Continuous Casting

Anglický název

Influence of Water Temperature on The Cooling Intensity of Mist Nozzles in Continuous Casting

Jazyk

en

Originální abstrakt

Small mist nozzles used in continuous casting were tested for heat transfer intensity. These nozzles are used in the secondary cooling area of a steel slab casting machine. Impact pressure distribution was measured first. Laboratory measurements of cooling intensity (heat transfer coefficient distribution) were performed with a variable water temperature. A temperature range from 20 degree C to 80 degree C was used in the tests. Surprisingly, the water temperature was found to have a strong influence. The most noticeable effect is a shift of the Leidenfrost temperature to low temperatures. Changing the water temperature from 20 degree C to 80 degree C caused a change of the Leidenfrost temperature of 130 degree C. This can be significant and can change the cooling character in the continuous casting machine. It is interesting that with an increase of the cooling intensity with a growing water temperature in a high temperature region (above Leidenfrost temperature), there is a small difference about 30 W/m2K. Surprisingly high differences in the Leidenfrost temperature were found for an intensive cooling where a difference of only 20 degree C in the coolant temperature makes a difference of about 100 degreeC in the Leidenfrost temperature. The results of the experiments performed with an elevated water temperature showed a high sensitivity of the cooling intensity to this parameter. The decreasing effect of the cooling intensity with the water temperature is more important for spray cooling of high intensities.

Anglický abstrakt

Small mist nozzles used in continuous casting were tested for heat transfer intensity. These nozzles are used in the secondary cooling area of a steel slab casting machine. Impact pressure distribution was measured first. Laboratory measurements of cooling intensity (heat transfer coefficient distribution) were performed with a variable water temperature. A temperature range from 20 degree C to 80 degree C was used in the tests. Surprisingly, the water temperature was found to have a strong influence. The most noticeable effect is a shift of the Leidenfrost temperature to low temperatures. Changing the water temperature from 20 degree C to 80 degree C caused a change of the Leidenfrost temperature of 130 degree C. This can be significant and can change the cooling character in the continuous casting machine. It is interesting that with an increase of the cooling intensity with a growing water temperature in a high temperature region (above Leidenfrost temperature), there is a small difference about 30 W/m2K. Surprisingly high differences in the Leidenfrost temperature were found for an intensive cooling where a difference of only 20 degree C in the coolant temperature makes a difference of about 100 degreeC in the Leidenfrost temperature. The results of the experiments performed with an elevated water temperature showed a high sensitivity of the cooling intensity to this parameter. The decreasing effect of the cooling intensity with the water temperature is more important for spray cooling of high intensities.

BibTex


@article{BUT93125,
  author="Miroslav {Raudenský} and Milan {Hnízdil} and J.Y. {Hwang} and S.H. {Lee} and S.Y. {Kim}",
  title="Influence of Water Temperature on The Cooling Intensity of Mist Nozzles in Continuous Casting",
  annote="Small mist nozzles used in continuous casting were tested for heat transfer intensity. These nozzles are used in the secondary cooling area of a steel slab casting machine. Impact pressure distribution was measured first. Laboratory measurements of cooling intensity (heat transfer coefficient distribution) were performed with a variable water temperature. A temperature range from 20 degree C to 80 degree C was used in the tests.
Surprisingly, the water temperature was found to have a strong influence. The most noticeable effect is a shift of the Leidenfrost temperature to low temperatures. Changing the water temperature from 20 degree C to 80 degree C caused a change of the Leidenfrost temperature of 130 degree C. This can be significant and can change the cooling character in the continuous casting machine. It is interesting that with an increase of the cooling intensity with a growing water temperature in a high temperature region (above Leidenfrost temperature), there is a small difference about 30 W/m2K. 
Surprisingly high differences in the Leidenfrost temperature were found for an intensive cooling where a difference of only 20 degree C in the coolant temperature makes a difference of about 100 degreeC in the Leidenfrost temperature. 
The results of the experiments performed with an elevated water temperature showed a high sensitivity of the cooling intensity to this parameter. The decreasing effect of the cooling intensity with the water temperature is more important for spray cooling of high intensities.",
  address="Institute of Metals and Technology",
  chapter="93125",
  howpublished="print",
  institution="Institute of Metals and Technology",
  number="3",
  volume="46",
  year="2012",
  month="june",
  pages="311--315",
  publisher="Institute of Metals and Technology",
  type="journal article in Web of Science"
}