Position: Dry Soda Ash Weight Feeder
Dry soda ash can be continuously fed based on volume or weight. Weight feeders are not subject to error when material density changes as are volumetric weight feeders with a belt weigher. Continuous feeding is different from simple conveying or batching because the flow of material must be maintained at a controlled rate. Almost any type of conveyor can be a weight feeder if it has a reasonably uniform discharge rate that can be varied by changing conveyor speed or amplitude or by throttling the flow to the Weighing feeder. Some of the better known Weighing feeders are: variable speed screw feeders; rotary pocket, star and vane feeders; belt weigher or apron weight feeders; oscillating tray, pan or undercut gate feeders with adjustable throws; vibratory feeders; and revolving table or disk feeders with adjustable scraper blades. These volumetric feeders can be calibrated by measuring discharge over a set time and are subject to error when the density of the material varies.
Gravimetic feeders measure the material being continuously fed to the process and have an endless conveyor partially or entirely supported on a scale. Scale position is transmitted to a primary feeder controlled to keep the weight of the material on the belt constant. Belt speed controls the discharge rate. The amount discharged is measured by integrating the travel of the belt.
The loss-in-weight feeder is a special case. This weight hopper scale has a discharge mechanism controlled by the scale beam that always keeps it in balance. A controllable drive moves the poise down the weigh-beam at a predetermined rate, which continuously unbalances the scale. Balance is restored by controlling the hopper's discharge rate. When the hopper is nearly empty, discharge ceases while the hopper is refilled. This system requires dual units for continuous flow. weight feeders should be checked dynamically by calibrating their delivery against a scale of known accuracy.
Feeding Solution about Dry Soda Ash
Soda ash solutions have uniform physical characteristics and are much simpler to meter than dry ash. When concentration, which is readily determined, is known, measurement can be made by volume as easily as weight. As a result, most liquid metering systems are volumetric.The metering equipment chosen depends on the feeding accuracy required. The concentration of batch quantities can be determined by its level in a tank, although the design should consider possible scaling effects and crystallization tendencies. A manual or automatic valve in the pipeline followed by a pressure gauge can be used to detect variations in flow (a rough correlation exists between pressure and flow rate).
Volumetric or proportioning pumps are commonly used when flow rate is low and measurement is secondary to flow control. This can involve any positive-displacement pump, such as a gear pump. Precision feeding usually calls for a special diaphragm pump (proportioning pump) that has an adjustable stroke and is protected by a strainer.
Various volumetric flow weight controller, such as rotameters, orifices, magnetic flow meters and turbine meters, indicate flow directly and continuously. They also can integrate quantity to provide direct or auxiliary control. Displacement meters, similar to those used for water and similar liquids, integrate flow quantity but may not give flow rate directly. Consult the meter manufacturer when procuring such equipment. Mass flow meters can measure flow rate, mass (weight), specific gravity and temperature. These meters can be alarmed to indicate changes in flow rate, mass flow (two phase flow caused by crystallization) and changing liquid concentration.
