Web Tech

Designers & Manufacturers of Weighing & Feeding Solutions

  • Ph: 1800 777 906

Loss-In-Weight (LIW) Feeders

Web-Tech Australia Pty Ltd
Ph: 1800 777 906
www.web-tech.com.au

Head Office, Brisbane
11 Electronics St,
Eight Mile Plains, Qld, 4113
Australia
Ph: (07) 3841 2844
International
+61 7 38412844
Fax: (07) 3841 0005

Sydney Office

11/5-7 Anella Avenue,
Castle Hill, NSW 2154
Ph: 1800 777 906

Web Tech designs and manufactures feeders and control systems for the dry material handling industry. In dry materials handling, the physical properties of the material directly affect the efficiency of the processing equipment, which ultimately affects the quality of the end product. Web Tech has designed its feeders according to the scientific concepts that govern material flow. The gravity flow feeders deliver a controlled, continuous and uniform flow across the entire outlet of the hoppers. The result is consistent material application providing consistent product quality. Web Tech has 30 years of experience with a wide range of feeding applications, from powders to developing highly specialized equipment for extremely hard to handle fibrous materials.Web Tech AutoWeigh manufactures a complete range of loss-in-weight/gain–in-weight feeders. These are available as Screw, vibratory and belt types, depending on the application. We can also custom manufacture for special applications. Loss-in-weight feeders can be used for a wide range of applications; however the accuracy and model required will depend on:

  • Material flow characteristics
  • Material bulk density
  • Material pre-feed
  • Particle size
  • Moisture content
  • Material aeration
  • Plant layout

You can view a material bulk density chart here.

LIW Integrator

LIW Material Bulk Density
Material Bulk Density 

Screw Type LIW Feeder 

Vibratory Loss in Weight Feeders

Belt Type LIW Feeders

Loss-In-Weight /Gain-in-Weight Feeder Categories

Web Tech loss­-in-weight feeders can be supplied for the following application types:

  • Loss-­In-Weight “Continuous”
  • Loss-In-­Weight “Batching”
  • Gain-In-­Weight “Batching”

Gain-in-weight feeding systems, as opposed to loss-in-weight, are used to deliver bulk solids into a batch process as a gain in the weight rather than a loss of the weight.

Loss-In-Weight Screw feeders

* Accuracies in the order of ±0.25% to ±0.5%.

Vibratory Loss-In-Weight Feeders

* Accuracies in the order of ±0.25% to ±0.5%.

Belt Type Loss-In-Weight Feeders

When a product cannot be fed through a screw or vibratory type feeder due to particle size or damage to the product, a belt type feeder can be a suitable alternative.

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.

multiple loss-in-weight feeder setup

 

*WebTech Volumetric type feeders can also be upgraded to loss-in-weight type if an increase in accuracy is required. The model of loss-in-weight feeder required depends on the material properties, application, and plant layout requirements. So that we can recommend the right feeder for your application, it is important that we know as much as possible about your application. Please complete our Loss-In-Weight Feeder Application Data Sheet and include as much information as is known. We also offer in-house testing of your product before recommending the best solution.

Example Materials

Absorbent powder, Alumina, Aspartame, Bauxite, Boric acid, Bran flakes, Bran flour, Calcium carbonate, Calcium sterate, Carbon black, Carbon fibres, Cellulose, Cereal, Chocolate, Detergent, Dextrose, Diatomaceous earth, Egg powder, Fibreglass, Flour, Fly ash, Fumed silica, Hydrated lime, Herbs, Kaolin clay, Microspheres, Oat flour, Phenolic Resin, Plant Material Polyester, Polypropylene, Psyllium, Salt, Silica gel, Soybean meal, Spices, Starch, Sugar, Sulphur, Talc, Teflon, Titanium dioxide, Rubber pellets, Vanilla powder, Whey powder, Zinc oxide & sterate.

Fibrous Materials can include

Carbon fibres, Cotton linters, Flock fibres, Graphite fibres, Chopped steel wool, Wet or dry chopped fibreglass, Synthetic fibres and Wool.

Loss-In-Weight/Gain-In-Weight Feeding Principles

A loss-in-weight feeder is a gravimetric feeder that receives material from a pre-feed device and accurately doses the material into a process at a pre-determined feed rate.

A loss-in-weight feeder operation is regulated by the amount of live load that is lost when product is discharged continuously.

In order to do this effectively, the loss-in-weight feeder receives constant feedback from a load cell and weighing controller. This ensures that an accurate amount of variations and vibrations provide repeatable accuracy

The loss-in-weight function does not directly impact on the material flow, therefore it is essential that the design of the storage vessel or pre-feed is correct and a suitable method of material transfer is selected.

The pre-feed must be sized to contain sufficient material to avoid variation in product flow when a low level is reached. The hopper capacity or pre-feed also defines the minimum flow rate that can be achieved from the loss-in-weight system.

Gain-in-weight feeding systems, are used to deliver bulk solids into a batch process as a gain in the weight.

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