Chemical Engineering @ChemengFiles.Com

Technip won from E. ON Ruhrgas UK North Sea Ltd. a fixed rate, worth about 32 million euros for the development of the Babbage gas field located south of the UK North Sea. Under this contract, Technip will install a system of submarine pipeline to export gas from the future platform to Babbage infrastructure existing submarine in the area of West Sole Bravo 500m, by 25 meters deep water.

The contract includes:

One of the most common elements in the chemical plant is the combination of centrifugal pumps and valves for flow control. Flow control valve opening and closing is obviously inefficient and that much of the energy supplied by the pump is lost by friction in the valve.

Thus the alternative of variable speed pumps is attractive. Using a variable speed drive using only the power required to move the fluid. This brings some other benefits due to the elimination of valves: A valve control minus isolation valves require less auxiliary piping and accessories.

This is a theoretical study of diffusion problems in transitional rarefied gases with surface dissociation and recombination reactions. The method of composite solution, which is a simplified version of the exact composite expansion theory with similarity to the mean free path method, has proved to be very successful.

Both the methods of Lester Lees and of composite solution have been used to solve the problem of simultaneous heat and mass transfer of a partially dissociated diatomic gas of transitional rarefaction from a hot fine wire to a surrounding cylinder. We have employed a sticking probability to describe the dissociation reaction of the diatomic gas at the wire but have used continuum type boundary conditions at the outer cylinder. We have also assumed a small total temperature variation and a small mole fraction of the dissociated atoms. The results obtained by both methods are identical and agree very well with the existing formulas in many limiting cases.

Owing to its simplicity, the method of composite solution was applied to the problem of a subsonic viscous flow past a sphere for small Mach number but arbitrary Knudsen number. This problem was considered both as a prerequisite for the investigation of mass transfer from a sphere to a stream of gas mixtures and as a means to acquire familiarity with the matching procedures. The result for the drag force agrees with the known formulas in both the free molecular flow limit and the continuum limit. The agreement with experimental data in the transitional flow regimes is less satisfactory.