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Oxygen-Deficient and Oxygen-Enriched Atmospheres
Published in John F. Rekus, Complete Confined Spaces Handbook, 2018
Investigators found an oxy-propane torch inside the space at the scene of the fire. Since it was not needed for the job, they suspected workers used it to ward off the early morning chill. When they no longer needed it for heat, they apparently used its high-pressure oxygen jet to blow scale off the wall. Oxygen accumulated and when one of the men lit a cigarette, he was immediately engulfed in flames. The second man tried to help him, but he was also engulfed in flames.
Engineering materials and heat treatment
Published in Roger Timings, Engineering Fundamentals, 2007
This produces a shallow case on simple components as shown in Fig. 4.16. The component is raised to red heat using a gas torch and brazing hearth.The red-hot component is then plunged into a case-hardening powder. This consists of carbon rich compounds plus an energizer as previously described.The component absorbs the powder onto its surface. This ‘carburizes’ the surface of the metal and increases its carbon content.The heating and dipping can be repeated several times to increase the depth of carbon infusion.Finally, the component is again heated to red heat and plunged immediately into cold water. If the case-hardening powder has done its job, there should be a loud ‘crack’ and any surplus powder breaks away from the surface of the metal.The surface of the metal should now have a mottled appearance and it should be hard. The component is now case hardened.Because this technique results in only a fairly shallow case, it is referred to as ‘superficial hardening’. The case is not deep enough for finishing by grinding processes, although polishing is permissible.Bright-drawn steels do not absorb carbon readily unless the drawn surface is removed by machining. Wherever possible use a case-hardening quality steel which is formulated and processed to suit this treatment.
Behavior of fly ash geopolymer as fire resistant coating for timber
Published in Journal of Sustainable Cement-Based Materials, 2019
Faiz Uddin Ahmed Shaikh, Sharany Haque, Jay Sanjayan
The geopolymer coated timber plates were subjected to direct fire test and the schematic of the fire testing is shown in Figure 4. As can be seen a portable butane gas torch is used to apply the fire continuously on geopolymer coating side. A temperature of about 1100 °C was developed on the geopolymer coating very quickly which was measured using a thermocouple as shown in Figure 4. In addition, two thermocouples were also used to measure the temperature on far side of the timber plate and approximately 2-3 mm behind the geopolymer coating by drilling a small hole, detail of which is illustrated in actual test setup in Figure 5. A silicon based heat sink compound was used to facilitate the heat transfer from the geopolymer coating to the thermocouple. It should be noted that the flame was kept 30 mm away from the geopolymer coating and maintained for about 10 minutes during which about 1100 °C temperature was generated as measured by the thermocouple on the coating side.
Effect of a sweeping air stream and gas–phase aspect ratio of an isothermal Stefan diffusion column on the experimental estimation of binary gas diffusivities
Published in Chemical Engineering Communications, 2019
Mya E. Graniela, Carlos A. Ramírez
The T-tube diffusion column (henceforth referred to as “T-tube” or “T”) was assembled from two standard 10 ml borosilicate glass pipettes with 0.1 ml graduations. A glass cutter (DB-100™ Mini Band Saw with Diamond Blade; Inland Craft, Westmont, IL, USA) was used to cut both ends of one of the pipettes leaving a length of 16 cm. This would later become the T’s horizontal leg. The second pipette (the T’s vertical leg) was cut to a length of 23.5 cm including the tip. All cut ends were fire-polished with a laboratory propane torch. The inside diameter of both sections was measured with a caliper (Digimatic CD-6” ASX Caliper; working range 0–150 mm; resolution 0.01 mm; accuracy ±0.02 mm; Mitutoyo Corporation, Kawasaki-shi, Kanagawa, Japan). Using a hand drill with a diamond-coated burr, a circular hole with diameter close to the inside diameter of the tube was made at a location 10.5 cm from one end (air inlet) of the horizontal leg. The two pipe sections were then flush-fused perpendicularly with the propane torch to make the T. The tip of the vertical section was also torch-sealed to prevent leakage. The T was set on a benchtop and allowed to cool at room temperature. Marine grade epoxy (PC-11® All Purpose White Epoxy Paste; working time 30 min; curing time 24 h; Protective Coating Company, Allentown, PA, USA) was then applied externally to the glass junction for support and to render it impermeable.
Experimental investigations on the stabilization of lifted kerosene spray flames with coflow air
Published in Combustion Science and Technology, 2018
Umesh Potdar, Omkar Pawar, Raghav Sikka, Sudarshan Kumar
The field-of-view of the camera, which is in pixels, needs to be converted into physical units, hence scaling is required. The focal plane between microscope and diffuser is decided by attaching the light torch to the microscope in shadowgraphy technique. The beam of torch is focused by adjusting the focal length with the help of adjusting screw of the microscope. A ruling scale in µm unit is placed in the focal plane. This scaling is applied to the image to convert pixel scaling to µm in the image in vertical and horizontal directions. The dimensions of the field of view are approximately 4 mm × 3 mm. The images are taken in the single frame mode in shadowgraphy. A similar procedure is applied for PIV measurements. The vertical ruling scale is focused with the help of lens and image is captured to scale the field of view. The FOV for PIV is approximately 50 × 45 mm. Once scaling is done, the experiments are conducted with the same setting between camera and region of interest.