Considerations regarding Ex d IIB + H2 method of protection for flameproof electrical equipment

MATEC Web of Conferences ◽

10.1051/matecconf/202235400042 ◽

2022 ◽

Vol 354 ◽

pp. 00042

Author(s):

Mihai Magyari ◽

Lucian Moldovan ◽

Marcel Rad

Keyword(s):

Electrical Equipment ◽

Round Shape ◽

Standard States

The flameproof enclosure type of protection is still one of the safest because it is based on a very simple and, therefore, unlikely fallible technology. If an explosive atmosphere penetrates an enclosure producing a trigger, the explosion occurs, but it remains confined within the enclosure. Engineers settled the concept that, for IIC areas, have to be necessarily used equipment with cylindrical flame paths, which usually feature a round-shape body that make more complicated the construction of panel boards. EN 60079-1 standard, states that flanged flame paths are allowed in the presence of hydrogen, therefore, in recent years, started the production of “Ex d” explosion-proof enclosures which are usable, as well as with gases of Group IIB, even in the presence of hydrogen. This means that the equipment can be used in an environment containing explosive atmosphere with hydrogen. Acetylene is, therefore excluded, but it has to be considered that the environments with the presence of hydrogen are much more frequent than those with acetylene. The purpose of this paper is to assist manufacturers design flameproof equipment that satisfies the requirements of the standard for group IIB and hydrogen applications in order to smooth the path for certification.

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Electrical equipment in aircraft: survey of past and present practice and future trends in design

Proceedings of the IEE Part A Power Engineering ◽

10.1049/pi-a.1956.0003 ◽

1956 ◽

Vol 103 (1S) ◽

pp. 4

Author(s):

S.F. Follett

Keyword(s):

Electrical Equipment ◽

Future Trends ◽

Present Practice

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Drilling and plombage (core decompression) of a femoral head avascular necrosis

Osteologie/Osteology ◽

10.1055/s-0037-1619921 ◽

2010 ◽

Vol 19 (01) ◽

pp. 36-39 ◽

Cited By ~ 1

Author(s):

P. Chládek ◽

V. Havlas ◽

T. Trc

Keyword(s):

Surgical Treatment ◽

Femoral Head ◽

Core Decompression ◽

Effective Treatment Option ◽

Simple Method ◽

X Ray ◽

Large Femoral Head ◽

Press Fit ◽

Round Shape ◽

Late Stages

SummaryThe treatment of femoral head necrosis of adults is still rather problematic. Conservative treatment has been reported relatively unsuccessful and surgical treatment does not show convincing results either. The most effective seems to be a surgical treatment in early stages of the disease, however, the diagnosis still remains relatively complicated. For the late stages (2B and above) the most effective treatment option is represented by core decompression and vascular grafting. However, drilling and plombage (especially when using press-fit technique) seems to be successful, although not excellent. The authors describe their own method of drilling and plombage of the necrotic zone of the femoral head in 41 patients with X-ray detected necrotic changes of the femoral head. The pain measured by VAS was seen to decrease after surgery in all patients significantly. The Jacobs score was also observed to have increased (from fair to good outcome). We have not observed any large femoral head collapse after surgery, moreover, in some cases an improvement of the round shape of the femoral head was seen. It is important to mention that in all cases femoral heads with existing necrotic changes (flattening or collapse) were treated. Although the clinical improvement after surgery was not significantly high, the method we describe is a safe and simple method of diminishing pain in attempt to prepare the femoral head for further treatment in a future, without significant restriction of the indication due to necrosis (osteochondroplasty, resurfacing, THR).

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