Mill Reject Hoppers
Rejected material from the coal pulverizing mill is discharged to the mill storage hopper. A relatively small unit, it is not intended for long periods of collection due to space limitations at the pulverizer. A seal on the hopper permits the unit to operate at the pressure of the pulverizer. After material is collected in the hopper, it is removed with a JETPULSION® pump and conveyed in a pipeline to either a storage/transfer tank, or to tie into the bottom ash system.
- Reduces installation and operating cost by providing intermittent operation
- Separate system permits mill rejects to be conveyed without interfering with bottom ash hopper operation
- Mill discharge gate isolates hopper during conveying mode and for safe maintenance
- Access door allows quick removal of oversize material without downtime
- Sizing grid traps material too large for pump to prevent plugging and minimize maintenance cost
- Constructed to NFPA guidelines
- Specialized water seal permits hopper to operate at the same pressure as the pulverizer
Please contact your local sales representative for more information.
Why use a Mill Reject hopper from UCC?[+]
At most coal burning plants, the rejects from the pulverizer mills are handled with the bottom ash. UCC systems provide hoppers for mill rejects to meet latest National Fire Protection Association guidelines, sized for up to eight hours of storage.
A JETPULSION pump below each hopper moves the material to a storage/transfer tank or to the bottom ash hopper. The transport pipeline beyond the pump must be sized for adequate velocity, since mill reject material have a high specific gravity. Higher conveyor line velocity is required to keep the material in motion.
In a typical pyrites transporting system, the mill rejects are moved to a tank for storage until they are taken to the bottom ash sluice pipeline system. This permits intermittent, controlled removal of the material, conserves power, and reduces the amount of time required for the system to operate. Since the larger bottom ash system is not operated continuously, water requirements are minimized.