LWF-15L-V Loss-In-Weight Vibratory Feeder
Thayer Scale Loss-In-Weight Feeders are designed to provide precision class accuracy and repeatability even in the harshest of industrial environments. They range in capacity from grams per minute to tons per hour.
These are the most versatile feeders in the industry. At the heart of each Loss-In-Weight Feeder is a THAYER scale that has been designed exclusively for the stringent requirements of Loss-In-Weight feeding.
Thayer Scale offers a powerful set of proprietary add-on accessories that are designed to defeat the problematic flow issues encountered by industry such as bridging, flushing, adhesion and cohesion. Comprehensive process solutions that can only come from a company with over sixty years of experience.
LWF-15L-V “Spiralator” Loss-In-Weight Vibratory Feeder
The LWF-15L-V “Spiralator” Loss-In-Weight Vibratory Feeder is designed to operate over a very wide operating range (typically 100:1), while assuring uniform, non-pulsating flow of difficult-to-discharge materials, whether they be fine cohesive powders or fragile interlocking particles of irregular shape. A slowly rotating (typically 2 rpm), non-agitating, conical wire-spiral within the hopper counteracts the material’s tendency to pack under its own weight by virtue of its “lifting” action throughout the stored material. The resulting reduction in consolidation pressures throughout the material mass assures that the stored material will not develop sufficient strength to form stable arches that can cause erratic flow or complete flow stoppage. The combination of this unique material conditioning system and a vibrating pan feeder assures that the material will be handled reliably and gently throughout the entire feeding range.
Two Feed Tray Designs
- Standard Mirror finished stainless steel tray is used for non-cohesive pellets, granules, fibers and flakes
- Optional, Patented elastomer membrane vibrating tray insert for cohesive/adhesive powders
- Patented insert creates a multiple node, standing (vibrating) wave which acts to shed any material that has a tendency to adhere to the conveying surface
Two Types Load Cells to Choose From
THAYER LVDT Load Cell
The LVDT Load Cell was specifically developed as the ideal adjunct to THAYER’S “reverse-action” Force Measurement Suspension System. It is essentially a precision and extremely durable “tensionstyle” force transducer that is manufactured in a fine series of force ranges to produce scale capacities from 10 to 500 lbs depending on the application. The LVDT is the ideal load cell for ” light loading” applications where mechanical tare loads represent as much as 10 to 40 times the net material load and provides unparalleled overload protection at 1000% of rated output.
THAYER Strain Gauge Load Cell
The Strain Gauge Load Cell is available in force ranges from 25 to 500 lbs with an overload protection of 300% of rated output.
Weight Measurement System
The heart of any gravimetric feeder is its scale system. The LWF-15L-V incorporates a unique flexure suspension scale designed exclusively for use on Loss-In-Weight Feeders:
- High efficiency “dead load” counterbalancing
- Non-tilting platform design
- Tolerant of shocks and overloads
- Mechanical force “summing” to a single load sensor
- Full range sensor utilization = maximized resolution
- Low mechanical resonance frequency
Flexure plate system eliminates all wearing parts, such as bearings, pivots and knife edges and is not susceptible to vibration. Flexure suspension system transfers all loading forces to a single load transducer, which accurately measures load regardless of load position. Most platform scales are not designed to be immune to side loading and/or tortional loading caused by the plant environment and by the movement of the feed screw, agitator, etc. These factors can cause poor accuracy and poor calibration stability. Thayer’s flexure system cancels all horizontal force vectors and also allows heavy tare loads (weight of feeder and hopper) to be completely mass counterbalanced , permitting load cell sizing based on net rather than gross weight.
- Accurately measures load regardless of load position
- Immune to support structure deflections and process vibrations
- Inherently self aligning to gravity
- Nulls out heavy tare loads
- 1,000% over load capacity
- Scale may be suspended from above or supported below
- Immune to shock or impact loads
- Easily accessible load cell can be accessed without removing the feeder