A vacuum surface flashover switch is being considered for > 10 kHz operation in a 250 kV, 10 ohm, 40 ns coaxial water Blumlein. Various possible switch designs are compared, and two promising ones selected for tests in the switch test facility at LLL. The initial test configurations are described.

Pulverized coal has been an increasing important source of energy over the past century. Most large utility boilers, all modern coking plants, and many industrial boilers and blast furnaces employ pulverized coal as a major feed stream. In periods of oil shortages, such as during World Wars I and II, the concept of adding powdered coal to oil for use in combustion equipment originally designed for oil has been actively pursued but rarely used. Over this same period of time, there have been attempts to use air suspensions of coal dust in diesel engines in Germany, and in turbines in various countries. The economic advantages to be enjoyed by substitution of powdered coal in oil are not generally realized. Oil costs at $30/bbl represent a fuel value of about $5.00/10/sup 6/ Btu; coal at $25/ton is equivalent to approximately $1.00/10/sup 6/ Btu. Although capital costs for the use of coal are higher than those associated with the use of oil, coal is clearly becoming the least costly fuel. Not only are considerable cost advantages possible, but an improvement in balance of payments and an increase in reliability of fuel supplies are other potential benefits. It is therefore recommended that increased …

The 5MW(e) Dual Boiling Cycle Geothermal Power Plant, hence referred to as the Raft River plant, is being developed for DOE by EG and G, Inc., Idaho Falls, Idaho. This pilot power plant is of the binary concept and utilizes isobutane as the working second fluid. The plant will demonstrate the feasibility of power generation from an intermediate temperature ({approx} 290 F) resource. The plant is schematically diagrammed in Figure 1. During the final design phase and after the major components were specified to be made of carbon steel, and ordered, various conditions forced the power plant design to switch from surface water to geothermal fluid for the condenser cooling loop make-up water. Because the geothermal fluid contains significant concentrations of chlorides and sulfates, about 1000 ppm and 65 ppm respectively, aeration in the cooling tower causes this water to become extremely aggressive, especially in the pitting of carbon steel components. Although essentially all of the condenser cooling loop materials are carbon steel, the isobutane condenser and turbine lube oil cooler are the most vulnerable. These components are tubed with carbon steel tubes of 0.085 and 0.075 inch wall thickness. These two components are extremely leak critical heat exchangers. For …