Blow-torches

Hot work on plant, or in areas where flammable materials are handled, e.g. arc or gas welding (see also Eigure 5.4), flame-cutting, use of blow torches, grinding chipping concrete, introduction of non-sparkproof vehicles. 

A warning about glass blowing The flame of a glass blowing torch should never be directed into the neck of a flask because the mixture of air and unburnt gas is very likely to explode violently. 

A 48-year-old painter is referred for evaluation of recent onset of severe abdominal pains, headaches, and myalgias. For the last week, he has been removing old paint from an iron bridge using grinding tools and a blow torch. His employer states that all the bridge workers are provided with the equivalent of "haz-mat" (hazardous materials) suits. What tests should be carried out Assuming positive test results, what therapy would be appropriate ... 

Reverse-Rumford. As noted in Sidebar 3.1, Count Rumford observed that the work performed by a horse on the cannon-bore was exactly compensated by the heat expelled from the cannon-bore to the surroundings, demonstrating the heat/work equivalence demanded by the first law. Imaginably, the process might have occurred in the opposite direction, with heat added to the cannon-bore (e.g., from a blow-torch) appearing as equivalent work performed on the horse (e.g., driving it backward in its hoofprints), in equal harmony with the first law. Yet such a reverse-Rumford process has never been observed. 

Oxy-acetylene flame is a very useful tool in modem industry as it can cut through steel slabs and weld them together again. In the oxy-acetylene flame, oxygen and acetylene from separate cylinders are fed into a blow torch. The gases are mixed thoroughly and burnt at the tip of the blow torch. The products of this combustion are carbon dioxide, water vapour and heat. 

The bonnet opening of the disabled valve body below Tank No. 7 provided a steady stream of fuel to create a blow-torch like flame aimed beneath Tanks Nos. 5, 6, and 7, which threatened the equipment. Within a short length of time, safety relief valves on these tanks opened with a loud shrill sound to cope with the heat-induced rising pressure in the tanks. 

The form of furnace to be recommended for this work is represented in Fig. 6. It consists of a cylinder of fire clay, 7 inches high and 7 inches in external diameter, which is surrounded by a sheet-iron casing. It is heated, as shown, by a blast lamp introduced through an opening in the lower part of one side. If a suitable air blast is not available, a gasoline blow torch (such as is commonly used by plumbers) is serviceable. 

There are two types of solders soft and hard. Soft solders usually consist of a mixture of lead and tin and the heat required to melt them is supplied by a soldering iron. Hard solders include brass (copper-zinc alloys) solders, silver solders, copper solders, nickel-silver solders, and solders for light alloys the heat to melt them is usually supplied by a blow torch. 

Butane is used as a fuel in lighters, small blow torches, and camping stoves. It is also used in calibrating instruments and as a food additive. In addition, it is a raw material for organic synthesis. 

Thallium metal (m.p. 303°) is available from Alfa Inorganics in the form off in. rods. A clean section of it is grasped in tongs and melted with a propane blow torch and the molten metal let fall into a 2-1. beaker full of cold water. 

OTHER COMMENTS used as a gasoline additive for automotive, aviation and farm equipment used in solvent extraction processes, as a general laboratory solvent, and as a medium solvent for polymerization reactions used in the synthesis of amyl chlorides for intermediates in manufacture of paint, lacquer solvents, hydraulic fluids, paint removers, and miscellaneous petrochemicals used in the synthesis of polychlorocyclopentanes as intermediates in manufacture of fire-resistant polyester resins and paints, dye intermediates, and plasticizers use as a heat-exchange medium, a component of lighter fluids and blow-torch fuel, and in the manufacture of polystyrene beads for styrofoam production. 

When all the nitrogen dioxide has been collected, remove the receiver from the freezing mixture, take the delivery tube out of it, and let it warm up to a little below the boiling point of nitrogen dioxide then seal the tube at the constriction, using a small blow-torch flame. This operation calls for a little skill, since the... 

Blow-torches NG, LPG, C2H2, H2 Welding and cutting of metals... 

Natural gas, LPG, acetylene and hydrogen are used as fuels for blow-torches. 

The burners described here are meant to obtain temperatures of the order of 1000-1200°C. But a whole range of burners also exists, which are meant to produce lower temperatures of the order of 500 as well as blow-torches for very different uses machine blow-torch, oxy-arc cutting, soldering, glass blowing, jewellery. 

Heat the sodium using either the hottest part of a roaring Bunsen flame (the tip of the blue cone) or the kitchen blow torch until it catches fire. 

Light the magnesium ribbon with the tip of the blue cone of a Bunsen flame or with a kitchen blow torch. Stand back. 

A UK inventor, Michael Keenan, has developed additives that are said to make PU foams resistant to a blow torch. The technology is being commercialised by Brandingplus Ltd. 

Bolt fixings may be corroded and the use of a blow torch to free them may not be permitted in the area. 

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