Ammonia Compressor Packs: Bitzer US Inc.
Bitzer is now offering a range of compressor units for use with the natural refrigerant ammonia (R717). The Bitzer ammonia compressor packs (ACP) are available with a capacity range of 100 to 450 TR. The modular compressor units comprise up to three compressors. For higher capacities, as many as three compressor packs can be connected (up to 9 compressors) and connected to a single controller, increasing the overall capacity up to 1,200 TR. The company says this is ideal for industrial systems.
The primary compressor is equipped with a frequency inverter and insures optimal part-load performance. Bitzer officials said the compressor units are extremely efficient, as individual compressors can be turned on and off depending on requirements. In addition to the Bitzer compressors, the system also offers two new developments: both the oil separator and the controller were specifically developed for the ammonia compressor units.
The company explained that multiple Bitzer ammonia screw compressors increase the operating reliability compared to a single industrial compressor in the same performance class. Both the controller and the primary sensors are redundant to increase system reliability. The ammonia compressor packs are designed for use in areas subject to stringent requirements in terms of operating reliability. System downtime in the food and chemical industries, for instance, can result in high costs. The ACPs ensure greater reliability here in particular.
The frequency-regulated primary compressor features an insignificant starting current peak. With automatic start unloading, the second and third compressors in the unit boasts lower starting current peaks compared to similar individual compressors providing the same overall cooling capacity. As a result, the starting current peaks are reduced by approximately one-third. Because the starting peak load is lower than that of conventional systems, components such as cables and contactors can be smaller, reducing installation costs. Monitoring the application limits with alarm and shut-off limits and operating parameters ensures maximum reliability. If the operating parameter limit is exceeded, the controller automatically takes countermeasures.