Avara Manufacturing Industry Utility Steam Improvemets

At Avara Pharmaceutical Services, located in Arecibo, Puerto Rico, the manufacturing facility is comprised of a heating system from which a vital utility for the process is obtained, referring to vapor. The mainstay technology used to generate the high-pressure, high-temperature utility steam is a diesel oil fire tube boiler, whose efficiency is currently compromised by several factors, some of which are thermal losses experienced by the system and parameters controlled by the equipment that precedes do not benefit the process. Thermal losses in the form of radiation and convection, as well as the effectiveness of the heat exchanger is accounted for in the determination of the boiler overall efficiency, also denominated fuel-to-steam efficiency. For this heating system design, the primary concern is the operating cost of the plant; which is mostly dependent on the energy source of the boiler, referring to the diesel oil.
The overall boiler efficiency represents the difference between the energy input and energy output of the system. A fire tube boiler that has been operating over a period of twenty years may have a maximum efficiency of 85%; however, typical efficiency values range between 65% to 75%; through calculation the efficiency of the fire tube boiler was found to be 71%. For this case, 29% of the energy input exits through the equipment’s chimney with no appreciable benefit. Several energy saving considerations where proposed to the client, where the heat recovery from the flue gas through the implementation of a four-coil rectangular economizer would make the process feasible. Implementing the economizer would increase the efficiency of the equipment to 76%, lower the diesel consumption to 364,000 gal/ year, which reflects an annual saving of $69,000 from which Avara Pharmaceutical Services would benefit.

Author(s):

Roxanna Vazquez    
Chemical Engineering
Polytechnic University of Puerto Rico
Puerto Rico

Heidy Sierra    
Chemical Engineering
Polytechnic University of Puerto Rico
Puerto Rico

Jenmarie Acevedo    
Chemical Engineering
Polytechnic University of Puerto Rico
Puerto Rico