Top blow

KHD-Contop [from the German company, KHD Humboldt Wedag, and Continuous top blowing] A steelmaking process. 

In the blow and blow process the gob is dropped into an open blank or parison mould. The neck is formed by top blow and then the parison or blank is blown from the base (Figure 6.2). The blank shape supported by the transfer ring is then transferred to the finishing mould where it is blown into the final shape. This blow and blow process is the major process employed—usually with IS (i.e. independent or individual section) machinery Other machines include Roirant R7, S10 and Lynch 44. IS machines may have 4, 5, 6, 8, 10 or 12 stations. For small containers double, triple or quadruple gobbing may be employed. The last can give speeds of over 400 containers per minute. 

Steel is made from pig iron chiefly by the open-hearth process (by which over 80% of that produced in the United States is made), the Bessemer process, and the oxygen top-blowing process. In each process either a basic or an acidic lining may be used in the furnace or converter. A basic lining (lime, magnesia, or a mixture of the two) is used if the pig iron contains elements, such as phosphorus, that form acidic oxides, and an acidic lining (silica) if the pig iron contains base-forming elements. 

The extractor consists of a glass cylinder A, terminating at the base in the open tube B. Fused within the top of A as shown is another tube C, having a small hole D blow n in the side a fine glass tube leads from the base of C, rises about two-thirds of the height of the cylinder to E, and then returns past F into the open tube B. 

Ether. The most satisfactory method for the removal of (diethyl) ether is either on a steam bath fed from an external steam supply or by means of an electrically-heated, constant-level water bath (Fig. 77, 5, 1). If neither of these is available, a water bath containing hot water may be used. The hot water should be brought from another part of the laboratory under no circumstances should there be a free flame under the water bath. It caimot be too strongly emphasised that no flame whatsoever may be present in the vicinity of the distillation apparatus a flame 10 feet away may ignite diethyl ether if a continuous bench top lies between the flame and the still and a gentle draught happens to be blowing in the direction of the flame. 

Answer Figure 15.5.2-1 shows the "percolator" scheme. At the top of the a reactor vessel, presumably the hottest location, is a diaphragm that blows out if the reactor exceeds the maximum allowable pressure. It is attached by an alloy that melts at that the... 

A very delicate and useful piece of apparatus, which is leadily made with the blow-pipe, is Perkins modification of Sprengel s pyknometer. It is especially adapted for small quantities of liquid and for the moie volatile ones. The apparatus (Fig. 46) consists of a U l ube to hold from 2 to 10 c.c., drawm out at each end into a fine capillary. The one capillaiy limb, a, is bent outwards and is furnished with a small bulb the other, b, is bent at a right angle with the first. On the limb a, between the bulb and the top of the U-tnbe a mark is etched. The... 

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