Thayer Scale volumetric auger based feeders are used to reintroduce ground coffee that has been recovered from filters and flexible sleeves installed on grinding equipment in order to top off final ground coffee blends.
After collection, recovered material is screened and loaded into intermediate bulk-material handling containers that are in turn loaded into hopper bottom discharge stations. The intermediate bulk-material handling container discharges directly into a volumetric feeder, adding back recovered material at an extremely low rate.
Thayer Scale Equipment for Green Bean Blending
Thayer Scale’s patented volumetric feeder trough features a unique geometry that consists of a large upper “U”-shaped conditioning chamber and a lower tear-dropped shaped feed chamber.
The dimensions of the upper conditioning chamber exceed rat hole diameters and critical arch dimensions. A horizontal agitator installed in the upper conditioning chamber consists of two separate convolutions concentrically mounted to the same shaft. These convolutions simultaneously draw material from the front and rear of the trough, promoting uniform draw down of the product through the feeder. Unlike brute force agitation systems, Thayer Scale’s horizontal agitator moves through the material, conditioning the product by maintaining a uniform bulk density and attenuating aeration for reliable delivery to the metering auger. This agitator also deflects material on initial fill, diminishing material’s kinetic energy to prevent uncontrolled flushing / flooding through the metering auger eliminating the need to maintain an excessive product heel to absorb product impact between refills. The independently driven horizontal agitator conditioning action remains uniform irrespective of the metering auger speed and can be installed / removed without tools.
The deep lower feed chamber allows the metering auger submerged in “quiet” material free from surface disturbances created by the agitator turning above. The “tear-drop” shape provides a larger wrap-around angle for complete & efficient filling of each metering auger flight, promoting longitudinal flow while minimizing the effects of head pressure dependency. The feed chamber also features progressive material confinement, tapered in the direction of material flow to relieve dynamic compression forces as each metering auger flight advances towards the confined area of the discharge tube.
The volumetric feeder is capable of discharging nearly its entire contents because there is no gap gradient between the feed chamber and discharge tube.
Add back is indistinguishable from the main grind blend because the metering auger configuration conveys material with minimal product degradation. Metering auger drive shafts are engineered for easy tool-free installation / removal into the reducer’s hollow shaft bore via manual rotation of an eccentric cam lock. Should foreign debris in the material stream bind the metering screw, an inexpensive, easy to replace sacrificial shear pin mechanically decouples the metering auger from the drive shaft, preventing damage to the auger flights.
Each metering auger comes with its own set of food safe non-rotating shaft seals that are easily inspected, removed or replaced to support deep cleaning, microbiological assessment, and pathogen testing requirements whenever the metering auger is removed from the trough.
The volumetric feeder is designed for fast, easy, and thorough clean out. The feeder completely disassembles in minutes with no hand tools.
Weighing equipment for the processing of coffee
Weigh belts
- Highly-accurate for reliable, repeatable measurements and batch control
- Available with open or enclosed construction
- Designed to fit new or existing process flow streams
- Cantilevered conveyor assembly simplifies maintenance
Loss-in-weight feeders
- Auger discharge
- Vibratory pan discharge
- Feed rates from grams/minute to tons/hour
Hopper and silo material flow promotion solutions
- Provide consistent, uninterrupted material flow
