Development and Testing of a New Thermal-Acoustic Industrial Insulation

Abstract

This article grew out of a project to investigate the feasibility of applying current engineering technology to the control of noise exposures in modern electric generating plants. In the course of the project, a new insulating product, which successfully combines both acoustical and thermal insulating properties, was developed and operationally tested in an electric generating plant. The product consists of a composite of several materials selected to provide attenuation of noise and process heat. The result is a reusable, flexible insulating blanket that can be custom fitted to any shape of process equipment.

Following laboratory tests of several candidate materials, one was selected for full-scale tests on high-speed boiler-feedwater pumps in an electric power plant. The field tests showed a noise reduction of 10 to 30 decibels in the frequency range of 250 to 4000 Hz. It is thought that at least 10 decibels of mid-frequency noise attenuation can be achieved on noisy process equipment such as high-speed pumps, turbines, and control valves. Heat stress conditions in the area of the pumps were also alleviated as the result of a temperature reduction of 6°K (10°F) dry-bulb. An investigation is being conducted to determine if this represents a significant thermal energy gain in the process feedwater—a factor which could offset the cost of the insulation. The insulation is asbestos-free, and the removal and replacement of individual components are achieved without generation of excessive airborne dust. Trayer, David M.; Thornton, C. C.; Lehman, C. B.: Development and Testing of a New Thermal-Acoustic Industrial Insulation. Appl. Ind. Hyg. 4:45–49; 1989.