Choosing the right portable air compressor for a Cold Jet’s /Aero 2 Dry Ice Blasters (PCS 60 & PLT 60)
In choosing the right compressor to carry out dry ice blasting it is imperative knowing first and foremost the range of applications where dry ice blasting will be applied. For example, not all applications need the same “brute” force. Certain applications demand a minimal consumption of air, less than 1.5 cbm of air per minute, others demand a volume flow in excess of 3.5 cbm of air per minute reaching values of up to 5 cbm of air per minute. Such constant volumes of air can be easily achieved through a screw compressor. Piston type compressors cannot match such delivery and they tend to be much noisier.
For sure, the AERO 2 series (PCS60 and PLT60 blasters) dry ice blasters cater for such a variety of applications thanks to the fine adjustments these machines are able to offer combined with the different suite of nozzles available. These come in different shapes and sizes, starting from the precision low flow, and ranging up to the high flow units. What concerns the compressor, it is important knowing what is the maximum Free Air Delivery (FAD) of the compressor @ 5.5bar pressure (typically FAD is always quoted at the compressor’s working pressure). All compressors are pressure regulated, however the OEM sets the machine’s regulation values and it is not advisable to make changes to these. However, pressure regulation can be easily attained though the addition of an external pressure regulator at its exit flange.
Another aspect that is sometimes overlooked is the quality of air. Air, needs to come free of contaminants, free from oil (thanks to an oil filtering unit) and as much as possible free from moisture (this is a general rule for all pneumatic driven tools). All of the top brands cater for both. However different brands offer different solutions for the delivery of condensate free air without any external additional equipment. Top brands use a combination of “after-cooling” and a condensate separator making sure that the delivered air is free from condensate. Condensate free air, avoids having ice forming at the dry ice blaster’s nozzle. Icing can create a situation where small ice formations are expelled with the dry ice, something most operators would prefer avoiding for a number of reasons. With lower quality dry ice blasters, the issues become worse as partial clogging of the nozzle’s exit can occur, hindering the blasting activity.
It is also worth noting that “dry” air can only be fully attained through the use of an external air dryer (in this case desiccant air dryers). Most top brands offer the possibility of an integrated dryer, however, it is all a question of how important dry air is for the activity being carried out. Care must be taken when selecting the dryer model. It has to be matched with the compressor’s FAD, Operating Pressure, Relative Humidity and Loading Factor. A lesser capacity dryer will obviously create resistance to airflow, which is not something anyone would want.
Another aspect that may need to be considered, is whether one blaster will be used in conjunction with the same compressor. Whether it is a blaster or another pneumatic tool, the same compressed air will be shared (rarely equally) amongst the tools being used. It is important to consider whether the available air will be sufficient to drive both at an acceptable level. In some cases, an air buffer tank might be recommended to reduce the possibility of “choking” one of the tools out of air and saving the air compressor from frequent load variations. Regular load variations experienced by a compressor, imply also a higher wear and tear of the machine.
Last but not least electricity supply. Most blasters required a standard 220Vac, 4 to 6 A current. Most top brands offer an incorporated electricity generator as part of the compressor package, saving costs and space.
Ing. Robert Busuttil