The reason being primarily because of the narrow operating window in which the systems will perform with stability. It is necessary to constantly change the gas amounts for varying conditions in the system. Therefore, the heart of all dense phase systems is the gas control device. It must be flexible and accurate. A lack of training by the customer can have negative results on system performance.
Much information is needed for proper design.
Dense phase systems are not as flexible as dilute phase systems when it comes to varying product transfer capacities, varying products, or varying product grades that result in dissimilar physical product characteristics. Even product temperature variations need to be known at the design stage and incorporated into the system design. The system designer can build in some additional flexibility, but they need to know the customer's process and process requirements for the transport system. It is extremely important for the system designer to have an understanding of the total process leading into and out of the conveying system. Many systems are working great.