Undercut Gates are generally used to control the flow of large (+4?) material. They are generally of very robust construction to withstand the high impact loads and wear. Undercut gates can be designed to easily close through a column of large material without jamming. This is because the tolerances can be made large and the pinch point at the closed position easily eliminated. Undercut gates are not applicable for metering flow, are difficult to seal, and require more headroom than some other gate designs.
Applications Some typical applications include: • Mass flow gates are installed on the discharge of mass flow silos, bins and hoppers to regulate the discharge without disturbing the mass flow characteristics. • Some bulk material storage stockpiles are equipped with mass flow reclaim hoppers to prevent arching and rat holing and to increase the amount of material that can be reclaimed by gravity. These reclaim hoppers can be discharged by mass flow gates.
Actuators The actuators available for use on mass flow gates are: • Hydraulic • Pneumatic • Electric over Hydraulic • Electric
Actuators Mass flow gates can be fabricated from or equipped with a wide range of construction materials depending on the characteristics of the bulk material being handled.
Some examples of construction materials for different applications are: • Carbon Steel with polished stainless steel or low friction plastic liners to promote flow can be used for most applications. • Stainless steel can be used in all areas in contact with acidic material to prevent corrosion. In some instances it may be necessary to fabricate the entire gate from stainless steel.
Position Indication Since mass flow gates are used to regulate flow, it is essential to have a method of determining the position of the gate blade Some of the devices available to determine the gate blade position is: • A limit switch can be used to detect whether the gate is closed, open or any pre-set intermediate position. • A proximity switch can be used to detect the closed, open or any preset intermediate position. • A sensor can be used to continually detect the gate blade position. • Integral position indication is available from actuator manufacturers to indicate the gate blade position.
HMA Group | Specialty Industrial Equipment
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