Modifying packing rings said to improve turbine efficiency.

Modifying Packing Rings Said To Improve Turbine Efficiency

A consulting engineer here has developed a technique of modifying the packing rings on steam turbine shafts that reduces wear and can improve turbine efficiency by approximately 1 percent and generating capacity by 1 to 3 percent.

According to Ronald Brandon, an associate consulting engineer for Power Technology Inc. here, large continuously operating industrial steam turbines between 100,000 and 1 million kilowatts typically require new packing rings about every five years. Large steam turbines generally have about 50 packing rings, and about half the rings need to be replaced at any one time.

Packing rings cost about $4,000 per ring, and replacing 25 rings would cost about $200,000, he said. Brandon noted that his ring modification process, which involves remachining conventional packing rings to specific dimensions, adds between $1,000 and $2,000 to the cost of each ring.

Depending the price of fuel, the technique can save about $1,000 annually for each megawatt of power produced, and the procedure can pay for itself in one year or less, he said.

He added that the remachining procedure will ...