T3 Loss-in-weight Bulk Bag Unloader

For unloading by weight

Processors around the world handle dry bulk powders and ingredients in bulk bags. At Spiroflow, we specialize in high containment bulk bag filling and unloading systems – offering the most comprehensive range of standard and custom unloading equipment in the business.

Our T3 loss-in-weight bulk bag unloader allows you total control over the amount of product you wish to dispense from the bag. This can be varied for individually selected batch amounts, or fully interfaced with your plant process control for continuous batch production.

The T3 loss-in-weight bulk bag unloader incorporates all the proven features of our Universal T2 model, but the bag support dish is mounted on four load cells. This enables highly accurate weighing of your product as it is discharged from the bag. If necessary, the integral transfer conveyor can also be suspended from the weigh frame as shown opposite, to provide a totally self-contained discharge and loss-in-weight dispensing unit.

Features

  • Dust-free
  • All Bag Types
  • Total Containment
  • Controlled Dosing
  • Batch or Continuous Weight Control
  • Wide Range of Models & Accessories
  • HOW IT WORKS & FEATURES
  • MODELS & SPECIFICATIONS
  • YOUR UNLOADING REQUIREMENTS
  • COMPONENTS & OPTIONS
  • CONTROLS
  • SPECIAL APPLICATIONS

HOW IT WORKS & FEATURES

The T3 Loss-In-Weight Unloader is used when unloading by weight.

This bulk bag unloader is of all welded construction with a bag support dish that will accommodate most bottom-spout bulk bags.  The bag spout passes through the middle of the dish where it can be accessed.  The bulk bag provides the seal against the support dish for a dust free seal.  Our exclusive design mounts the four (4) load cells & summing box high on the frame between the frame & support dish, out of the way of harm, water & dirt.  The system can be used with a number of options including our various controls options. The discharge of the chute is custom made to fit the application.

How It Works

Our T3 bulk bag unloaders are simple and easy to operate.  The basic sequence of operation is as follows.

  1. A bulk bag of product is fitted with the Bag Lifting Frame.
  2. The operator lifts the bulk bag into place with a forklift.
  3. The Lifting Frame sits on the Side Tensioning Frame.
  4. The weight of the bag compresses the springs & the bottom of the bulk bag rests on the Support Dish.
  5. With the weight of the bag safely supported, the operator can now freely access the bottom spout of the bag.
  6. The operator opens the access door & unties the bag spout.
  7. As the bag empties, the springs in the side frame will keep a constant tension on the bag ensuring complete emptying of its contents.
  8. Material falls into the chute & the integral conveyor moves material to the next step in your process.
  9. When empty the operator reties the bottom bag spout & removes the bag & lifting frame.

Features

  • Batch or continuous weight control – load cells are located at the mid-section, preventing the risk of damage by forklifts and dirt/debris when located at the base of the unit.
  • Recipe management system
  • Bag tensioner ensures complete emptying of bag
  • Integral conveyor or feeder
  • Full dust control
  • Designed to discharge poor flowing materials
  • Suitable for all bulk bag types and sizes up to 6.5 ft (2 m) high and 2 tons (1.8 tonnes) in weight

MODELS & SPECIFICATIONS

The T3 bulk bag unloader is one of several designs we offer.  Features of our various models are typically mixed and matched to accommodate specific application needs.  And, of course, we regularly build custom designs.  Here is a list of our basic models.  Your Spiroflow Sales Engineer will evaluate your needs and recommend the best configuration to do the job.

MODELDESCRIPTION
T1Entry level basic frame design available in the UK & Europe
T2For unloading by volume
T3For loss-in-weight unloading
T4For unloading single trip bags
T5For discharging in low headroom areas
T6Includes an integral hoist when a forklift truck is not available to load/unload bags into/out of the bulk bag unloader
T7For unloading multiple types of containers including bulk bags, rigid bins & boxes/octabins
T8For USDA/3A applications
T9-CVFor total containment when handling volatile or explosive materials
T10 & T11For pharmaceutical applications
Flo StyleFlo Style unloaders, from our purchase of Control & Metering, have a 40º or 60º sloped hopper that supports & shapes the bag for ease of discharge. Pulse vibration, instead of massage paddles, is used to induce material flow. The bag is kept elongated via gravity throughout discharge. It can be configured as a T2, T3, T4 or T6.

Specifications

Description

The T3 Loss-In-Weight Unloader is used when unloading by weight.

This bulk bag unloader is of all welded construction with a bag support dish that will accommodate most bottom-spout bulk bags.

The bag spout passes through the middle of the dish where it can be accessed.

The bulk bag provides the seal against the support dish for a dust free seal.

The heavy-duty 3" (80 mm) square steel tube frame is welded directly to the support dish.

Our exclusive design mounts the four (4) load cells & summing box high on the frame between the frame & support dish, out of the way of harm, water & dirt.

The system can be used with a number of options including our various controls options.

The discharge of the chute is custom made to fit the application.

Standard Materials of Construction

Carbon/mild steel is standard.

Optional 304 or 316 stainless steel is available.

Pneumatic Requirements

Side Massage: 80 PSI (5.5 Bar) at 2 CFM (56.6 L)/Cycle
Corner Massage: 80 PSI (5.5 Bar) at 4 CFM (113.3 L)/Cycle
Bottom/Dish Massage: 80 PSI (5.5 Bar) at 1 CFM (28 L)/Cycle
Spout Closure Bars: 80 PSI (5.5 Bar) at 1 CFM (28 L)/Cycle
Note: If run continuously 8 L/min @ 5.5 bar
Chute/Hopper Vibrator: 80 PSI (5.5 Bar) at 3 CFM (85 L)/Cycle
Dust Collector: 80 PSI (5.5 Bar) at 35 CFM (991 L)/Cycle

Electrical Requirements

Optional Chute/Hopper Vibrator: 0.13 hp (.1 kW)
Optional Hopper Agitator: 0.33 hp (.25 kW)
Optional NEMA 4/ATEX Panel with ON/OFF Switch for Vibrator or Agitator: 0.33 hp (.25 kW)
Optional Dust Collector: 1.5 hp (1.1 kW)
Optional Level Probe: 24V DC

Dust Control/Air Displacement

Dust Extraction Port
Optional Integrated Dust Collector: NEMA 4, TEFC (Stainless Steel Only)
Optional Integrated Dust Collector: XP (Stainless Steel Only)
Optional Free-Standing Dust Collector: NEMA 4, TEFC (Stainless Steel Only)

Check out our Bulk Bag Unloader Comparison Chart 

This document compares our bulk bag unloader offerings based on design options.  Of course, our engineers will assess your application needs & recommend the optimal design.

YOUR UNLOADING REQUIREMENTS

Before purchasing a bulk bag unloader always ask these key questions:

  • Will the bulk bag unloader accept varying bag sizes?
  • Will the bulk bag unloader handle poor flowing products?
  • Is there a forklift available or is an integral hoist needed?
  • Does the bulk bag unloader provide a controlled flow when the spout is opened?
  • Does the bulk bag unloader have a bag tensioning device to ensure all product is discharged?
  • Is discharge of the bag contents required by weight or by volume?
  • Is there provision for restraining and/or removing the inner liner?
  • Is an integral take-off conveyor required?
  • Is there a height restriction?
  • Is there a way to empty small bags in case the bulk bag supply of material is interrupted?
  • Does your plant require a hygienic bulk bag unloader or USDA/FDA approved equipment?
  • What dust control features are incorporated into the bulk bag unloader?
    • When untying the bag spout
    • While the product is being discharged
    • When the inner liner is being removed
    • When the bag is removed and folded for disposal
  • Is the product or environment hazardous?
  • Is static grounding and monitoring required?
  • Is the environment covered by NEC regulations?

COMPONENTS & OPTIONS

T3 Bulk Bag Unloader Components

Standard Components
Bulk Bag Unloader Support Dish & FrameThe T3 Loss-in-weight Bulk Bag Unloader is used when weighing of the bulk bag is required for inventory or for proportioning by weight. It is of all welded construction with a bag support dish that will accommodate most bottom-spout bulk bags. The bag spout passes through the middle of the dish where it can be accessed. The bulk bag provides the seal against the support dish for a dust-free seal. The heavy-duty 3 in./ 75mm square steel tube frame is welded directly to the support dish.

Our exclusive design mounts the four (4) load cells & summing box high on the frame between the frame & support dish, out of harm's, water & dirt.

The system can be used with a number of options including our various controls options.
WeighingLoad cells & junction box included.
Weigh display (no set points) available as an option.
Loss-in-weight controls, weight display & batch controller available as an option.

Options

T3 Loss-in-weight Bulk Bag Unloaders are designed to accommodate a combination of design options to meet your specific unloading application needs.

Optional Components
Bulk Bag Spout Closure BarsTwin opposing “V” shaped bars, mounted on pneumatic pistons, are used to untie the bag spout while maintaining dust containment. They are also used to close & retie the spout of a partially emptied bag.

It includes a manual hand actuated pneumatic control for extend & retract and a safety interlock to prevent operation of the spout closure bars when the untie chamber door is open.
Dish Cover AssemblyPneumatically operated cover for the dish. To protect the internals of the Bulk Bag Discharger from contaminates when no bag is present.
Integral Bag Dump StationThe Integral Bag Dump Station, fitted with an oversized welded bar working grid, allows the operator to add small bags of materials by accessing the hopper under the bulk bag unloader. This can be done even with a full bulk bag in place provided that the spout closure bars option has been installed.
Portable DesignOur mobile bulk bag unloader has additional cross-bracing of the support legs & heavy-duty castors.
Dust Seal Options
Rubber Membrane Dust SealThe rubber membrane dust seal is located in the support dish.
Peripheral Dust SealThe peripheral dust seal provides a double seal for single-trip bags that contain dusty or hazardous materials.
Lifting Frame & Liner Options
Bulk Bag Lifting FrameThe lifting frame is used to safely lift & move most bulk bags to & from the discharging station & is designed for use with either a forklift or our optional electric hoist.
The lifting frame is made of all-welded tubular steel. This lifting frame is compact, easily handled & weighs only 120 lb (.45kg).

It is rated to 4,400 lb (1,996kg) for forklift use & 2,200 lb (100kg) lifting load for hoist use.
Heavy-duty Bulk Bag Lifting FrameThe lifting frame is used to safely lift & move most bulk bags to & from the discharging station & is designed for use with either a forklift or our optional electric hoist.

The lifting frame is made of all-welded tubular steel. It is compact & is easily handled.
It is rated to 4,400 lb (2000kg) lifting load for hoist use.
Bulk Bag Liner ClampThe bulk bag liner clamp is mounted on the bag lifting frame. The liner clamp prevents the liner from collapsing, falling into the bag & fouling the discharge outlet.

This provides a positive method of securing the bag liner while the bag's contents are emptied.
Manual Hand Wheel Bag Liner TensionerThe manual hand wheel liner tensioner is mounted on the bag lifting frame. The liner clamp prevents the liner from collapsing, falling into the bag & fouling the discharge outlet.

The method of tensioning is done via a lockable hand crank.

This provides a positive method of securing the bag liner while the bag's contents are emptied.
Pneumatic Rack & Pinion Style Bulk Bag Liner TensionerMounted on the bag lifting frame, the pneumatically actuated liner tensioner retracts approximately 24” (610mm) of liner as the bag is being emptied.

For use with loose liners.
Bulk Bag Tensioning FrameThe spring-loaded frame is designed to stretch the bulk bag as it is emptied to promote complete discharge of all solids.

The frame will accommodate most bulk bag sizes & is adjustable both in height & spring tension.
Material Flow Aid Options
Bulk Bag Bottom Massage SystemTwin pneumatic pistons with large pusher plates are used to massage the bottom of the bulk bag to promote the flow of compacted materials.

It includes a manual hand actuated pneumatic control for extend & retract.
Bulk Bag Side Massage SystemTwin pneumatic pistons, mounted on the bag tensioning frame, with large pusher plates are used to massage the sides of the bulk bag to promote the flow of compacted materials.

It includes a manual hand actuated pneumatic control for extend & retract.
4 Corner Bulk Bag Massage SystemFour pneumatic pistons, mounted on the bag dish assembly, with large pusher plates are used to massage the corners of the bulk bag to promote the flow of compacted materials.

It includes a manual hand actuated pneumatic control for extend & retract.
Level Activated Massage ControlThe level activated massage control provides for automatic activation of the massage system on detection of low level in the hopper & stops upon detection of high level or if the unit times out.
Chute/Hopper Vibrator (Electric or Pneumatic)The electric chute/hopper vibrator is used to aid the flow of materials that can bridge in the hopper. This vibrator is NOT used to aid in the flow of material from the bulk bag - refer to the massage systems options.
Solimar Air Pad SystemThree aeration pads installed through hopper walls to inject & pulse air into the product to prevent bridging, ratholing and compacting of dry bulk materials.
Dish VibratorFLO 60 MODELS: An electric or pneumatic dish vibrator vibrates the dish to promote the flow of solids from bulk bag.
Hopper AgitatorThe hopper agitator is mounted across the lower section of the discharge chute/hopper.
It is used to promote the flow of materials & break up most soft agglomerates before entering the conveyor.

Motor starter controls are available.
NEMA 4 Panel with On/Off SwitchA NEMA 4 panel with an ON/OFF switch for a vibrator or an agitator.
Discharge Outlet Options
Discharge Chute/HopperLocated directly below the bulk bag support dish, the discharge chute provides an enclosed environment for accessing the bag spout & as a buffer hopper for up to 3 ft3 (.08m3) of material.

Access to the bag spout is through a side door which includes a dust tight seal, key lock, & viewing window. If fitted with the optional spout closure bars an interlocking limit switch will be provided.

The chute is provided with a vent port for connection to a central dust collector (by others). The chute/hopper is available with outlet connections to suit individual requirements.
Rotation AdapterThis is a 360° connection to downstream equipment.
Internal Polish for Discharge Chute/HopperThe discharge chute above with #4, 120 grit minimum internal surface & welds ground smooth & crevice free for internal surfaces only.
Level Probe Options
Hopper Level Probe (NEMA 4)A NEMA 4 Level Probe can be mounted through the side of the chute/hopper to indicate low and/or high solids level in the hopper.

It can be used to start & stop a conveyor.
Hopper Level Probe (Intrinsically Safe)The Intrinsically Safe Level Probe is mounted through the side of the chute/hopper to indicate low and/or high solids level in the hopper. Barrier by others.

For use in XP classified areas.

This can be used to start & stop a conveyor.
Dust Containment Options
Dust Extraction PortFor connection to plant dust extraction system.
Hygienic Bag Spout ConnectionThe Hygienic Bag Spout Connection is used to provide a sanitary connection between the bag spout & discharge chute/hopper. This will reduce the chance of getting contaminants that may be on the bag bottom from entering the solids stream. It includes an inner shelf in the discharge chute/hopper, center spout connection & quick connect clamp.
Integrated Dust Collector (NEMA 4, TEFC, or XP)This dust collector is integrated into the discharge chute & has 3 polyester membrane filter cartridges (45 ft2 / 1.27m2), a self-cleaning air pulse jet assembly with control circuit board, motor & fan.

Motor starter controls are available.
Free Standing Dust CollectorOur carbon/mild steel free standing dust collector has a hopper and pulse-jet filter blow down. It also has three (3) 30” (762mm) polyester membrane cartridges & can be provided with a collecting hopper with butterfly valves on legs.

Motor starter controls are available.
Explosion Proof/Hazardous Options
Static Monitoring SystemSpecifically design for use with Type 'C' conductive bags & a resistance range of 500 to 1x108 Ohms.
Glove BoxA glove box is an enclosed area that allows an operator to untie the bag with total containment.
A dust port, located at the rear with a dust sock on, can be connected to an extraction system fitted to the operator access door. The dust enclosure is equipped with a pair of heavy-duty long reach gauntlets. These allow the operator to gain access to the inside of the unit while being protected by the gauntlets.
If required, an outer secondary safety cover door is fitted over the opening to the glove box to prevent operator access through the gauntlets. This is required if the discharger is to be fitted with spout closure bars or to prevent operator access to moving parts.

Bag Massagers

Bag massagers aid the consistent flow of difficult materials from a bulk bag and are located either in the base of the support dish, at the corners or on the side frame. They are actuated by pneumatic cylinders and their position and frequency of actuation is fully adjustable. They are particularly effective if the material has been compacted from storage or when traditional (and noisy) vibration causes further compaction and hinders unloading.

Patented Spout Closure Bars

Spout closure bars have several functions: they prevent dust by allowing untying of the bag without product release; their aperture can be set to control the flow rate from the bag; they can close off the spout if used in a batch weighing operation, and they allow the bag to be re-tied and removed from the discharging frame.

Metering Feeders

Using our own flexible screw conveyor technology, or proprietary equipment, we are able to offer a comprehensive range of gravimetric and volumetric metering feeders for the reliable and accurate dosing of ingredients or additives into mixers, reactors, process vessels or liquid flows.

Spout Stretcher

Our pneumatic stretching and sealing device assists the flow of poor flowing or very light product through the bag spout and into a downstream vessel, valve or conveyor. It also provides total dust containment of dusty or noxious products.

Sieve

An integral vibratory sieve provides assurance that product from a bulk bag is suitably screened for lumps and other impurities before entering the discharge chute.

Mobile Frame

A robust mobile frame, with a towing facility if required, provides a versatile arrangement for processors who need to discharge bulk bags at several locations. (This option is not available for the T6 Bulk Bag Unloader with Integral Hoist).

Lifting Frame Liner Clamp

Bulk bags are often supplied with long inner liners which must be clamped at the top to prevent fouling the take-off conveyor.

Liner Remover and Tensioner

Liners can be removed from the bulk bag after unloading and contained without dust emissions with the use of this powered retraction device and compaction facility.

Bag Folding Table

A bulk bag folding table provides a practical solution to bag disposal problems and allows residual product extraction from the bulk bag.

Static Protection

Designed for use in hazardous atmospheres with a Type C static dissipative bag, the ground monitoring device automatically checks that the bag is correctly grounded before discharging can begin.

Bag/Sack Dump Door

We can supply a large bag/sack dump door so that if your supply of bulk bags is interrupted, smaller bags of raw materials can be emptied into the unloader.

Check out our Bulk Bag Unloader Comparison Chart 

This document compares our bulk bag unloader offerings based on design options.  Of course, our engineers will assess your application needs & recommend the optimal design.

CONTROLS

Our T3 bulk bag unloaders can be provided with controls with or without a VFD.  Motor starter controls are available to operate a dish vibrator, hopper agitator or dust collector. Of course, full loss-in-weight, weight display and batching controls are available.

Please share your controls needs with your sales engineer for full specifications.

SPECIAL APPLICATIONS

Although we have an extensive line of bulk bag unloaders we often design custom equipment for our customers.  Here are a few of our more unusual designs: