What Is a Bridge Breaker?
A bridge breaker is a device used to eliminate bridging (powder clogging). It is mainly installed in hoppers or tanks where powdered raw materials are used.
When the powder is used, the weight and pressure of the powder itself often cause the powder to harden near the discharge port in the hopper, preventing proper discharge.
Also known as rat hole breakers, there are vibrator, knocker, aerator, blow disk, and break rod types.
Uses of Bridge Breakers
In hoppers where powder is used, there is a possibility of powder clogging called bridging, as well as other abnormalities such as ratholes, in which powder sticks to the sides or top of the hopper.
If bridging or ratholes occur, the rotary feeder at the bottom of the hopper operates, but the powder cannot be fed according to the set weight. The vibrator type is used for this purpose.
The knocker type is used to break up bridges at once by delivering a strong impact to the hopper.
The aerator type is used to prevent bridges and ratholes by supplying air to the inside of the hopper without impact or vibration.
The other type is the blow disk type, which vibrates the inside of the hopper while supplying air, and the break rod type, in which a shaft (claw) is inserted into the hopper and rotated to eliminate bridging.
Principle of Bridge Breakers
The vibrator type uses a ball vibrator or a piston vibrator. In the ball vibrator, a built-in steel ball rotates at a high speed to produce vibration. Piston vibrators are of the cylinder type, and vibrations are produced by the piston motion of the internal cylinder caused by air. Both types are mainly pneumatic.
In the case of the knocker type, the piston type is the main type. When compressed air is supplied, it is directed to a part called the valve chamber and stored in a part called the storage chamber. When exhaust air is released from the three-way valve installed in the air supply piping of the knocker-type bridge breakers, the compressed air stored in the storage chamber moves the part called the knocker’s umbrella valve upward. After the umbrella valve moves, compressed air passes through the piston section, pushing the piston up vigorously.
The blow disk type has a silicon disk that vibrates inside the hopper to eliminate bridging. The disc is pushed up by a jet of air from just below the disc, thereby producing vibration.
The brake rod type can be manually unclogged. A handle is attached to the outside of the hopper, and turning it rotates a shaft inserted into the hopper, which stirs the powder. This type has the disadvantage of being more labor-intensive than the other components that are automatically controlled, and the hopper must be small enough to be installed.