PUMPS

References

1.0 INTRODUCTION

Pumping issues are among the most discussed topics in the mechanical recovery field today. In most cases the problems are with pumping a high viscosity, sometimes emulsified and debris-laden product. The search for suitable pumps for spill response is almost always focused on high viscosity fluids: highly weathered oils, emulsified crude oils, and Bunker C. Added to this list in recent years are emulsified fuel oils such as Orimulsion.

Efforts have been made in recent years to develop or adapt pumps to handle these highly viscous products. Archimedean screw pumps are a popular choice for this application, and have been added to several skimmers that had experienced problems pumping a highly viscous product during the Valdez spill and have performed very well. Peristaltic, or hose pumps are also effective in pumping viscous products and are becoming more widely used. Piston pumps also show evidence of effective operation even with the most troublesome forms of debris, and this is described in greater detail in the section on piston pumps.

Another approach has been to try to reduce backpressures and friction heads when pumping viscous fluids over long distances. The application of steam heating, annular water injection, and demulsifying chemicals have all been attempted with some success.

But with these exceptions, very little has been done to meet the pumping requirements of oil spill recovery. An apparent reason for this is that most pump manufacturers do not perceive the oil spill equipment market as being significant and therefore developing special pumps is not worth the investment. This perception is probably largely true. Until a substantial market for oil spill recovery pumps can be identified, there is not likely to be much effort devoted to producing these devices. There are a tremendous number of pump manufacturers in the U.S. that offer a dizzying number of types and models, but few of these are identified as being produced for oil spill response operations.

Not only are there few pumps that are identified for use in oil spill operations, there are also very few tests that have evaluated pumps for that purpose. In addition, the pump test information that is available is old. The most significant set of tests were performed in the summer and fall of 1977 by Environment Canada. At that time a contractor tested eleven pumps to rate their effectiveness for oil spill response [1]. This was followed by two much smaller test programs in 1979 and 1981. These reports, along with the Ohmsett tests summarized in 3.4, are the only body of literature known on the application of a range of pumps specific to oil spills. Many pumps tested during these studies are still available and used. However, most types with the greatest potential for success were not available when the above tests were performed. As a result, most information on newer pumps comes from reports of their application in actual spill situations, individual test programs, verbal reports of spill response managers, and product literature.

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(Twelve pages of text and references followed by twelve pages of pump data listings)