The MSV Pellet Feeder is the newest member of Thayer Scale’s Loss in Weight Feeder Range.
With over 75 years of experience, Thayer Scale offers the largest range of loss in weight feeders of any manufacturer. Thayer Scale’s range of loss in weight feeders includes vibratory feeders, screw feeders and ingredient batching systems. The loss in weight feeders incorporate a volumetric feeding subsystem designed to provide consistent, reliable metering of the target material at desired flow rates. The MSV Pellet Feeder, a screw feeder, is compact, easy-to-clean and economical. The MSV Pellet Feeder offers precise feed-rate control for free-flowing pellets and granules.
Loss in weight feeders are used extensively in many market segments including many of Australia’s growing heavy industries. Offering precise, continuous mass flow control in harsh operating environments they are commonly used equipment in mining operations to provide accurate blending and feeding of materials. The cement industry demands recipe accuracy and regulatory compliance where precision dosing of additives is critical. Australia’s heavy industry relies on loss in weight feeders as process critical equipment providing numerous performance requirements like cost control, compliance, precision dosing and automation in demanding remote and high-cost labor environments.
Thayer Scale’s Loss in Weight Screw Feeders
Thayer Scale’s Loss in Weight Screw Feeders include a Compact series, offering precision dosing performance, designed to fit where other feeders can’t, the General Purpose range, incorporating Thayer Scale’s proven cable suspension architecture and the newest member of the line, the MSV Pellet Feeder, an economical compact feeder for pellets, granules and other free-flowing materials.
MSV Pellet Feeder
The MSV Pellet Feeder pairs a rugged, economical volumetric feeder with a low-profile, mass-counterbalanced scale, resulting in a gravimetric feeder that provides highly responsive feed-rate control and accuracy in a small form-factor package. The cable scale features a robust, highly stable micro-lever system that delivers higher accuracy, fast responsiveness, longer gravimetric cycles and higher turn-down.
The higher load-cell utilization provides numerous benefits including higher accuracy, typically 0.25% of feed rate, fast responsiveness to changes in set point or material density fluctuations.
Higher load-cell utilization also enables the MSV Pellet Feeder to operate with longer gravimetric cycles, requiring fewer refills and less time operating in volumetric or “settling” mode and significantly higher turn-down. The system is designed to operate with the Thayer Scale Differential Screw solution, enabling consistent, pulse-free delivery of material across a wide operating range.
The gravimetric cycle
The gravimetric cycle is the time from the beginning of Gravimetric Feeding through the Refill Operation and Settling stage. The timing of the Gravimetric Cycle depends on the feed rate and the type of refill operation being employed. It can vary from a few minutes to an hour or more. Ideally, Gravimetric Feeding represents >80 per cent of the total feeding cycle.
Within the Loss-in-weight cycle, the feeder discharges material under closed-loop control during the “gravimetric feeding” portion of the cycle. Once the load sensed by the scale drops to the “initiate refill” sequence, a refill signal is initiated by the controller, and material flows from the storage hopper into the weigh hopper. During this time, the feeder operates in volumetric mode (or, in some cases an enhanced volumetric control if a dynamic setpoint is employed). The feeder settles once the refill is complete and then resumes gravimetric material delivery.
The controller monitors and controls the live load to deliver a consistent feed rate. During Refill, the live load data is unavailable and the controller PID control loop is temporarily bypassed resulting in a consistent screw motor speed. The Thayer Scale Loss-in-Weight controllers operate in a mode called VOLM which enables the feed rate to respond to setpoint changes.
Thayer Scale’s industry leading range of Loss-in-Weight Feeders is used in a wide variety of segments around the world including numerous installations in Australia. Their operating advantages satisfy the demanding operating conditions in the region, including remote sites, high labor costs where automation is essential, harsh conditions, high quality and compliance standards, energy controls and waste reduction. To learn more or to discover which Thayer Scale Loss-in-weight feeder is right for your application please contact Thayer Scale at Sales@thayerscale.com or www.thayerscale.com and a member of the team will reach out to you.
