Lances

A laboratory demonstration of this operation is far better than any written description. The tubes may be bought from many dealers e.g., A. Gallenkamp r Co. Ltd., Technico House, Christopher Street, London, EC2P 2ER, and Victoria House, Widnes, Lancs also The Scientific Glass- Blowing Co., 41 Upper Brook Street, Manchester 13), but students should learn to make their own c.apillary tubes. 

SIROCLEAR Siroc method Siroflash process Sirolan CF Siroscour Sirosmelt lance SIROSWDTS Sisal SISD... 

Other uses of oxyacetylene flames in mill operations are in building up or hardfacing metal, lancing (piercing a hole in a metal mass), and a variety of metal cleaning procedures. A minor but interesting fuel use of acetylene is in flame spectrophotometry where oxygen and nitrous oxide are used as oxidants in procedures for a wide variety of the elements. 

Isasmelt bath Patch process ak-cooled lance from top oxidation and reduction vessels connected by a launder... 

Bohden Kaldo flash and some bath reactions top-blown vessel using a water-cooled lance vessel rotates during smelting and reduction, and can be tilted for tapping... 

Dried lead concentrate, flux, and return dust are added to the converter through a lance during the smelting cycle. Oxygen enriched air is injected at the same time to carry out the smelting reactions and maintain the temperature. Once smelting is completed, the air is shut off and the reduction carried... 

The high lead slag from the smelting furnace is tapped continuously and transferred down a heated launder directly into the reduction furnace through a port in the side of the vessel. Lump coal for reduction is fed continuously to the furnace by conveyor and dropped direcdy into the bath. Heating for the endothermic reduction reactions is provided by oil injected down the lance. The combustion air stoichiometry is set at 95% of that required for complete oil combustion. Air is injected into the top of the furnace to afterbum the volatile materials from the coal and provide additional heat to the top of the furnace. Reduction temperatures range from 1170 to 1200°C to maintain slag duidity. 

Technology has developed for time to stabilize soil at a considerable depth (20). The U.S. method is called time slurry pressure injection, with time slurry being injected in situ to 3—6.6 m depth through lances on a grid-pattern but there is no mixing of time and soil. Both Japan and Sweden have developed techniques using specially constmcted machines to inject dry quicklime and then mixing the time, soil, and water to depths of 11 m or more under critical hydraulic conditions. 

A jet of gaseous oxygen is blown at high velocity onto the surface of a bath of molten pig iron and scrap at the bottom of the furnace by a vertical water-cooled retractable lance iaserted through the mouth of the vessel (Fig. 4). The furnace is mounted ia a tmnnion ring and can be tilted backward or forward. 

Fig. 4. Sketch of a basic-oxygen steelmaking furnace, where an oxygen lance is iaserted through the mouth of the furnace (1).

Refractory lining life was at one time an important maintenance cost, but developments using a nitrogen lance to splash slag over the walls have increased lining life by a factor of -- 10 (2000 to 20,000 heats). 

Fig. 11. Crimp terminal contigurations (a) straight battel, 90° tongue, where wine without insulation is crimped in the battel, (b) Open battel having insulation-piercing lances, (c) Nylon or poly(vinyl chloride) preinsulated terminal accommodating and supporting wine insulation. Wine without end insulation is insetted in the terminal and is crimped. The terminal sleeve is not broken but conforms to the shape of the crimp indent, (d) Quick disconnect...

The inside of the convection tubes rarely foul, but occasionally the Hquid unsaturates in feedstocks tend to polymerize and stick to the walls and thus reduce the heat transfer. This soft coke is normally removed by mechanical means. In limited cases, the coke can also be burnt off with air and steam. Normally, the outside surface of the convection section fouls due to dust and particles in the flue gas. Periodically (6 to 36 months), the outside surface is cleaned by steam lancing. With Hquid fuel firing, the surface may require more frequent cleaning. 

Combustible masking materials such as organic char may be partially or completely removed by periodic elevations of the catalyst bed temperature. Noncombustible masking materials may be removed by air lancing or aqueous washing generally with a leaching solution (20,21). 

Chemical Treatment. The most iavolved regeneration technique is chemical treatment (20) which often follows thermal or physical treatment, after the char and particulate matter has been removed. Acid solution soaks, glacial acetic acid, and oxalic acid are often used. The bed is then tinsed with water, lanced with air, and dried ia air. More iavolved is use of an alkaline solution such as potassium hydroxide, or the combination of acid washes and alkaline washes. The most complex treatment is a combination of water, alkaline, and acid washes followed by air lancing and dryiag. The catalyst should not be appreciably degraded by the particular chemical treatment used. 

Coil coaters operate equipment continuously and, in most cases, operate catalytic fume abaters 6000—7000 h/yr. Under these conditions the anticipated catalyst life is years, with an aimual aqueous solution cleaning. However, the catalyst may last no more than two years if frequent maintenance is needed, such as in-place air lancing every 60 to 90 days to remove noncombustible particulates. Erequent maintenance may be needed if coatings such as sihconized polyester (15—40% siUcones) comprise 30% of the coatings put through the system. 

The vessel cover is free of drive components, allowing space for additional process nozzles, manholes, explosion venting, etc., as well as a temperatrrre lance for direct, continrrorrs prodrrct-temperatrrre... 

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