Refractory castable with low cement, ultra-low cement and non-cement types inherently contain deflocculant to reduce water and increase flowability. The traditional installation method is casting with vibration or self-flowing which requires the higher manpower, but installation capacity is slow. Moreover, there are some areas of furnace where formwork is difficult to install.

There is a more advanced application method for deflocculated castable called wet shotcrete - refractory castable is wet mixed and then pumped at high pressure to the nozzle, where compressed air and coagulant additive are injected for spraying refractory castable into furnace lining. This method gives high installation productivity and good gunning quality. However, this installation equipment system is often large, complicated to operate, and pipeline system deployment is time and labor consuming. Therefore, wet shotcrete is only effective for large volume projects. Since then, the need for a refractory installation method that is simpler, more compact than wet shotcrete but faster and more effective than traditional casting has arisen. Recently the dry gunning solution for deflocculated refractory castable had been applied in the few countries overseas, based on traditional dry gunite method. With a compact, simple equipment configuration, easy to move and set up, this solution is very suitable for small and medium-sized refractory work projects.

Novaref has conducted research and development on adjusting the additives and optimizing particle size distribution in low cement castable to suit the dry gunning application, improving dry material flow and wetting ability, fast coagulation, good adhesion and reducing rebound loss, early strength development. Along with that is optimizing the configuration of machine parts and adjusting the structure of the traditional dry gunite machine to increase material uniformity in the nozzle and ensure even and continuous flow of material. Trial gunning had been carried out to evaluate gunning parameters to finally establish a complete dry gunning solution for low-cement refractory, ultra-low cement and non-cement castables. On that basis, our new product range of Novagun-xxLC, Novagun-xxSC and Novagun-xxNC for dry gunning application with different material grades, properties and uses purpose had been developed, manufactured, and applied by Novaref installation team in recent years. These products are quite suitable for repair work in many locations in cement kilns, iron ore pellet furnaces, hot air ducts, reheating furnaces, power plant boilers, incinerators, etc., helping to shorten furnace repair time.