Investigation of High Efficiency Pulsation Filter Bottle Design
A standard pulsation bottle design for reciprocating compressors utilizes two surge volumes connected by a single choke tube. The surge volumes and the choke tube work together to provide a low-pass filter system such that amplitude of the reciprocating compressor excitation orders above the low-pass filter frequency are reduced in the associated piping system. For modern variable speed compressors, tradeoffs exist between the necessary pressure drop in the pulsation filter bottle and its effectiveness at tuning out the compressor dynamic excitation. Large speed ranges tend to make the tradeoffs even more difficult. Higher horsepower machines have resulted in higher flow velocities and dynamic pressure losses. In many systems designed to filter 1x orders and above, the API limit of 1% pressure drop is easily approached, in order to provide sufficient pulsation control. Through the GMRC 2009 research, SwRI began investigating slight modifications to the filter bottle design to improve the inlet / outlet flow losses. This effort intends to remove the associated “pressure drop tax” on an effective pulsation bottle. Borrowing concepts for the aerospace and automotive industries, a number of design modifications have been modeled. These design modifications must still maintain the classic volumechoke- volume filter style in order to be effective pulsation control bottles. This paper will review the fluid dynamic simulations of high efficiency bottle concepts and the associated pressure drop predictions. These fluid dynamic models are supported by a solid physical basis for pressure recovery evidenced in the literature. The authors will review the fluid model stream patterns as a means of understanding the pressure recovery capabilities of the various concepts. Results showed the high efficiency bottle to be capable of 50-55% pressure drop recovery through modifications to the choke tube design alone. The practical adaptation of these high efficiency bottle concepts and their impact on future pulsation bottle design theory will be presented as well.
2009 GMRC Gas Machinery Conference, Atlanta, GA, October 5-7, 2009
Gas Machinery Research Council
Broerman, E.L., Tavares, T.S., Iyengar, V., and Nored, M.G., "Investigation of High Efficiency Pulsation Filter Bottle Design," Presented at the 2009 GMRC Gas Machinery Conference, Atlanta, GA, October 5-7, 2009.