Melt core casting

Procedure. Core floods were carried out in horizontally mounted Berea sandstone cores of length 61 cm and diameter 5 cm. Porosity varied from 18 to 25% and brine permeability from 100 to 800 Jim2. The cores were coated with a thin layer of epoxy and cast in stainless steel core holders using molten Cerrobend alloy (melting point 70°C). The ends of the cores were machined flush with the core holder and flanges were bolted on. Pore volume was determined by vacuum followed by imbibition of brine. Absolute permeability and porosity were determined. The cores were initially saturated with brine (2% NaCl). An oil flood was then started at a rate of lOm/day until an irreducible water saturation (26-38%) was established. 

Impellers shall have solid hubs. Impellers made from a cored pattern are acceptable if the core is completely filled with a suitable metal that has a melting point of not less than 260°C (500°F) for pumps with cast iron casings and not less than 540°C (1000°F) for pumps with cast steel casings. 

The principal impurities in item (1) were the undesirable isomers of TNT DNT their presence lowered the mp (Setting Point) of a-TNT from 80.75° to 80.2° (Specification grade) and could lower it much more. On castin g TNT in the shell, the outside of the cast solidified first because or the cooling effect produced by the metal walls of the shell, while the center portion of the cast solidified last, because it was somewhat insulated. As the result of this cooling, the mixture that sol i di f i ed - a C the outside contained a large proportion of high melting components, while the portion that solidified in the center core contained the bulk of the impurities because they solidified at a lower temperature. 

In the Watertown Arsenal method, the metal is melted in batch lots of the required weight in high-frequency induction furnaces and poured into a horizontally mounted mold rotating at 1300rpm while it is cooled on the outside with water. The mold is made of heavy cast iron and machined inside to the desired shape of the exterior of the gun to be produced. The finished casting has a hollow core and can be easily bored out to the desired internal diam of the gun(Ref 3)(See also Ref 2a)... 

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