Screw Type Loss in Weight Feeders

• A supply hopper
• Variable speed Screw Feeder mounted on a scale platform
• Web-Tech’s “Optimus Plus” microprocessor based electronic controller. The electronic controller measures the “loss in-weight” of material as it is metered out of the screw feeder. It then calculates the actual discharge rate (expressed in kg/hr, tonnes/hr, lbs/hr or tons/hr) which is continuously compared to the desired set point, with any deviation corrected by the controller. When the material in the supply hopper reaches a predetermined level, the screw speed remains constant whilst the hopper is refilled. After the fill operation is completed and the weight reading is settled, the controller goes back into the “loss-in weight” mode.Should you require a proposal from us for any application you may have, please complete as much of our “LIW Feeder Application Data Sheet” as is known, and we would be pleased to provide our recommendations.*Web Tech Volumetric type feeders can also be upgraded to Loss-In-Weight type if an increase in accuracy is required.We also offer in-house testing of your product before recommending the best solution.

Model “LIW1500”

The “LIW1500” is ideal for all applications that require consistent and accurate metering of powders, pellets and granules.

It is suitable for industries such as Plastics, Food, Chemicals, Building Products, Water Treatment and many others.

• Easily disassembled for cleaning purposes.
• Mild steel powder coated or stainless steel construction.
• Internally polished options available (stainless steel).
• Optional polished screws for food grade applications.
• High performance polymer sealing options.
• Optional agitation.
• Multiple extension hopper options.
• Flexible silicon bellow connections available.
• Accuracies in the order of ±0.25% to ±0.5%.

Brochure

Model “LIW2000”

The model “LIW2000” is one of Web Tech AutoWeigh’s medium capacity Loss-In-Weight feeders. It is suitable for applications including powder and granular materials.

• Available in both single and twin screw configurations.
• Up to 4 m³/hr capacity.
• Easily disassembled for cleaning purposes.
• Mild steel powder coated or stainless steel construction.
• Optional polished screws for food grade applications.
• High performance polymer sealing options.
• Optional agitation.
• Precision stainless steel shear beam load cells.
• Multiple extension hopper options.
• 10:1 turndown, other options available.
• Flexible silicon bellow connections available.
• Accuracies in the order of ±0.25% to ±0.5%.

Brochure

Model “LIW3000”

The model “LIW3000” is one of Web Tech AutoWeigh’s large capacity Loss-In-Weight feeders.
It is suitable for applications including powder and granular materials.

• Up to 30 m³/hr capacity.
• Easily disassembled for cleaning purposes.
• Mild steel powder coated or stainless steel construction.
• Internally polished options available – stainless steel only.
• Optional polished screws for food grade applications.
• High performance polymer sealing options.
• Optional agitation.
• Precision stainless steel shear beam load cells.
• Multiple extension hopper options.
• 10:1 turndown, other options available.
• Flexible silicon bellow connections available.
• Accuracies in the order of ±0.25% to ±0.5%.

Metering screw type is selected based on the application.

The size and pitch of the augers are selected to provide a minimum of 110% of the required throughput. Should you require a proposal from us for any application you may have, please complete as much of our “LIW Feeder Application Data Sheet” as is known, and we would be pleased to provide our recommendations.

Brochure

“EASYFLOW Fibreglass” Loss-In-Weight Feeder

Web Tech AutoWeigh manufactures a special version of its range of “EasyFlow” vibratory feeders.

The unique design makes it suitable for fibrous materials such as chopped fibreglass, typically used in the building products industry.

Chopped fibreglass is a difficult material to handle and feed.

Web Tech AutoWeigh has designed a special, fully contained system, which is now used by a number of companies in this industry.

The feeder size is determined by the type of fibreglass and the flow rates required.

In-house testing determines the geometry of the feeding element that best suits the material and ensures consistent throughput.

The “EasyFlow Fibreglass” Loss-In-Weight feeder is normally supplied as fully enclosed. Other features include diversion chutes to allow stored product to be diverted away from the process stream.

• Available as “continuous” or “batching” types.
• Ideal for “batching” type applications due to the smooth output and instant material shut off when stopped.
• Custom designed to suit the material properties to ensure the minimum of vibration for the material to start discharging. LIW Rev F 2015-01 7
• Ideal for delivering toppings or seasonings over its full width.
• All stainless steel construction for durability.

Special Applications

Apart from our standard designs, we also design and manufacture Loss-In-Weight Feeders for “special” applications, where our standard designs are not suitable. These designs have previously included:

• Individual designs in 3D CAD to fit into existing line layouts.
• Custom engineered pre-feeders.
• Supply of ancillary equipment such as valves.

Loss-In-Weight Controller

Web Tech AutoWeigh designs and manufactures its own range of electronic integrators and controllers that can be used with all of our Loss- In- Weight Feeders. Our standard model for Loss-In-Weight applications is the model “Optimus Plus” integrator and controller.

Features include:

• Automatic calibration.
• 64 x 240 pixel graphics LCD display.
• Remote Setpoint.
• Control outputs for refill.
• 4-20mA rate output.
• Excessive “Refill Time” alarm.
• “Deviation” alarms and “Hopper Low Level” alarm.
• Optional serial communications.
• Power supply 65-260 VAC, 50/60Hz (optional 24VDC)
• IP66/Nema4X Reinforced Polyester Enclosure

Brochure

Gain-In-Weight and Loss-In-Weight Batching Systems

For specialized Gain-In-Weight and Loss-In-Weight “batching” applications, we recommend the Rice Lake Weighing range of “920i” controllers.
Rice Lake 920i features include:

• Large backlit LCD graphical display.
• Customized display features.
• Display up to four scale channels per screen.
• 10 programmable display screens.
• Selectable A/D measurement rate up to 60 /second.
• Control of multiple scales Address
• 32 scale accumulators
• Multiple set points
• 4 communication ports
• NEMA 4X/IP66 stainless steel enclosure

Should you require a proposal from us for any application you may have, please complete as much of our “LIW Feeder Application Data Sheet” as is known, and we would be pleased to provide our recommendations.

Web Tech can also supply the ancillaries associated with Loss-In-Weight equipment such as:

• Silicon Bellows
• Augers and Screws
• Load cells