Research of heat stresses in components of blast furnace tuyere

Using computer simulating in Deform 2D it was researched the effect of insert thickness and air gap size, separating it from the internal cylinder, on temperature pattern and stresses in the insert and the internal cylinder. It was shown, that with the increase a clearance between the insert and the internal cylinder and with increase the insert thickness, weight average values of voltage decrease in it. They have been more evenly spread with increases of insert thickness. In tuyere design it was offered increasing it thickness to 13 mm for hardening. Key words: tuyere, blast furnace, insulation insert, internal cylinder, temperature pattern, stress.

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The relationship of blast furnace tuyere failure to tuyere heat transfer capabilities

JOM ◽

10.1007/bf03378680 ◽

1968 ◽

Vol 20 (3) ◽

pp. 53-57 ◽

Cited By ~ 4

Author(s):

C. M. Sciulli

Keyword(s):

Heat Transfer ◽

Blast Furnace ◽

Blast Furnace Tuyere ◽

Relationship Of ◽

The Relationship

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Do air-gaps behind soft body armour affect protection?

Journal of the Royal Army Medical Corps ◽

10.1136/jramc-2016-000759 ◽

2017 ◽

Vol 164 (1) ◽

pp. 15-18 ◽

Cited By ~ 2

Author(s):

Lee Tilsley ◽

D J Carr ◽

C Lankester ◽

C Malbon

Keyword(s):

Ceramic Composite ◽

Air Gap ◽

The Body ◽

Gap Size ◽

Soft Body ◽

Air Gaps ◽

Body Armour ◽

Ballistic Protection ◽

Back Face ◽

Full Metal Jacket

IntroductionBody armour typically comprises a fabric garment covering the torso combined with hard armour (ceramic/composite). Some users wear only soft armour which provides protection from sharp weapons and pistol ammunition. It is usually recommended that body armour is worn against the body with no air-gaps being present between the wearer and the armour. However, air-gaps can occur in certain situations such as females around the breasts, in badly fitting armour and where manufacturers have incorporated an air-gap claiming improvements in thermophysiological burden. The effect of an air-gap on the ballistic protection and the back face signature (BFS) as a result of a non-perforating ballistic impact was determined.MethodsArmour panels representative of typical police armour (400x400 mm) were mounted on calibrated Roma Plastilina No 1 and impacted with 9 mm Luger FMJ (9×19 mm; full metal jacket; Dynamit Nobel DM11A1B2) ammunition at 365±10 m/s with a range of air-gaps (0–15 mm). Whether or not the ammunition perforated the armour was noted, the BFS was measured and the incidence of pencilling (a severe, deep and narrow BFS) was identified.ResultsFor 0° impacts, a critical air-gap size of 10 mm is detrimental to armour performance for the armour/ammunition combination assessed in this work. Specifically, the incidences of pencilling were more common with a 10 mm air-gap and resulted in BFS depth:volume ratios ≥1.0. For impacts at 30° the armour was susceptible to perforation irrespective of air-gap.ConclusionsThis work suggested that an air-gap behind police body armour might result in an increased likelihood of injury. It is recommended that body armour is worn with no air-gap underneath.

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Experimental study of heat and moisture transfer in vertical air gap under protective clothing against dry and wet heat exposures

International Journal of Clothing Science and Technology ◽

10.1108/ijcst-06-2020-0091 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Yun Su ◽

Miao Tian ◽

Yunyi Wang ◽

Xianghui Zhang ◽

Jun Li

Keyword(s):

Natural Convection ◽

Protective Clothing ◽

Moisture Transfer ◽

Heat Exposure ◽

Air Gap ◽

Gap Size ◽

Heat And Moisture Transfer ◽

Content Type ◽

Wet Heat ◽

Heat And Moisture

PurposeThe purpose of this paper is to study heat and steam transfer in a vertical air gap and improve thermal protective performance of protective clothing under thermal radiation and hot steam.Design/methodology/approachAn experiment-based model was introduced to analyze heat and moisture transfer in the vertical air gap between the protective clothing and human body. A developed test apparatus was used to simulate different air gap sizes (3, 6, 9, 12, 15, 18, 21 and 24 mm). The protective clothing with different air gap sizes was subjected to dry and wet heat exposures.FindingsThe increase of the air gap size reduced the heat and moisture transfer from the protective clothing to the skin surface under both heat exposures. The minimum air gap size for the initiation of natural convection in the dry heat exposure was between 6 and 9 mm, while the air gap size for the occurrence of natural convection was increased in the wet heat exposure. In addition, the steam mass flux presented a sharp decrease with the rising of the air gap size, followed by a stable state, mainly depending on the molecular diffusion and the convection mass transfer.Originality/valueThis research provides a better understanding of the optimum air gap under the protective clothing, which contributes to the design of optimum air gap size that provided higher thermal protection against dry and wet heat exposures.

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