Dry and liquid flow rate sensing, combined with rapid response ratio control, provides an unusually high degree of accuracy. In addition to process monitoring and control, the unit provides an on screen read out of process events, and stores process data.
A product surge bin with high and low level indicators is used in conjunction with the control system so unit will run only when dry product is available.
Product is conveyed by a drag bar to ensure even, non-surging flow into the spray chamber or directly into the blender. The rate of flow is easily changed by raising or lowering a bed leveling plate or adjusting feeder with the VFD. Self cleaning feeder is wide enough so that only a thin bed of material will feed into the spray chamber. For gravimetric arrangements, the feeder inlet is positioned above the fulcrum point and product flow is measured by a load cell for optimum accuracy.
The dry flow is baffled into a thin stream which free falls through the spray chamber. The product stream is sprayed from both sides to assure maximum coating. The use of air assist spraying ensures penetration, even if the liquid is too low to generate an adequate spray pattern, and allows the use of spray nozzles with large orifices to minimize plugging caused by foreign material.
Liquid is delivered via a pump with a VFD drive and a flow meter. For gravimetric arrangements a mass flow meter is used with the meter and VFD drive controlled by the system’s main controls providing maximum accuracy and rapid response time.
A continuous blender is positioned under the spray chamber to facilitate additional particle-to-particle coating. The blender can be low, medium, or high intensity depending on process requirements.