Continuous-flow conveyors control

Process industries frequently need to weigh and control the flow rate of bulk material for optimum performance of such devices as grinders or pulverizers, or for controlling additives, eg, to water suppHes. A scale can be installed in a belt conveyor, or a short belt feeder can be mounted on a platform scale. Either can be equipped with controls to maintain the feed rate within limits by controlling the operation of the device feeding the material to the conveyor. Direct mass measurement with a nuclear scale can also be used to measure and control such a continuous stream of material. 

When the solid is one of the reactants, such as in ore roasting, the flow must be continuous and precise in order to maintain constant conditions in the reactor. Feeding of free-flowing granular solids into a fluidized bed is not difficult. Standard commercially available sohds-weighiug and -conveying equipment can be used to control the rate and dehver the solids to the feeder. Screw conveyors, dip pipes, seal legs, and injectors are used to introduce the solids into the reactor... 

In the continuous drying of BALL POWDER, dewatered powder is fed into a series of vibrating pan conveyors. Fresh air is preheated and blown into an air distribution manifold where tubes direct the air flow into the powder. An aerated bed is obtained by controlling the powder flow rate, the pan conveyor vibration speed, and the heated air supply. The air supplies the heat for evaporating the water. The water vapor is removed with the exhaust air by vacuum transfer. 

Ideally, the head of the material should be maintained at a height that is exposed to half of the auger and should not vary by more than 25 mm (Asphalt Institute 2007). Today, many pavers have automatic controls that continuously regulate the flow of the asphalt from the hopper through the conveyors to the augers. 

Since there is a simple relationship between sterility and, absorbed dose, sterility is controlled by the dose value, which, in turn, is usually controlled by the conveyor speed. Therefore, long-lasting microbiological tests are required only occasionally. It increases the safety of sterilization and simplifies the process. The process is continuous, allowing smooth product flow and requiring minimum human handling. 

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