Big bag systems · Discharge

BSB big bag discharge stations

Dust-free, quick and safe discharge of bulk bags filled with bulk solids. We design every station individually: from the dimensions of the frame and the flow aid system to the way the bag is loaded and the process interface that suits your line.

Explore the BSB station Hoist or fork-lift truck?

up to 2,000 kg bag lifting capacity up to 2500 mm bag height FDA · ATEX · GMP compliance of the build

What dust-free big bag discharge is

Discharge without dust, losses or risk to the operator

Emptying big bags by hand means dust in the plant, losses of expensive raw material, a risk to operators’ health and no control over how much material has been issued. BSB discharge stations, also called big bag emptying stations or bulk bag unloaders, enclose the whole process in a sealed, dust-tight system: from lifting the bag to discharging the material into the process.

Unlike catalogue products, every station is designed from the ground up: an integrated electric hoist on an overhead rail does away with the fork-lift truck, pneumatic massagers assist the flow of poor flowing materials without disturbing their structure, and the dust-tight docking module seals the bag to the station. The modular construction allows the station to be extended later, as process requirements change.

2,000 kg

maximum lifting capacity, with a lifting frame carrying the bag’s 4 loops

2500 mm

maximum height of big bag handled

1500 × 1500 mm

typical frame footprint; height matched to the application

The BSB station in brief

+Dust-free emptying of big bags weighing up to 2,000 kg and up to 2500 mm tall
+Loading by integrated electric hoist on an overhead rail, or by fork-lift truck
+Flow aids: pneumatic massagers, a support table with a vibrator, spout stretching
+A dust-tight, double-ring docking module with adjustable lid pressure
+ATEX, FDA, GMP and HACCP builds; painted carbon steel or AISI 304 / 316L
+Integration with feeders, pneumatic conveying and the plant control system

The BSB discharge station

A structure tailored to the application

BSB big bag discharge station with an integrated electric hoist on an overhead rail

BSB station installations (click to enlarge)

Two-station big bag discharge unit for granola, with gentle feeding and a tubular disc conveyor — Discharging granola

Four big bag discharge stations with electric hoists above the feeders at a food production plant — Food production plant

Two big bag discharge stations with screw feeders and docking modules at a sugar factory — Sugar factory

A multi-station big bag discharge system with ingredient weighing and pneumatic conveying — Multi-ingredient batching line

A BSB station consists of a supporting frame, a bag loading system, a flow aid system and a dust-tight docking module. We match the frame dimensions, the lifting capacity and the equipment to the size of the bags, the properties of the material and the space available. We do not offer a single standard model.

The frame is of powder-coated carbon steel or, in the hygienic build, of AISI 304 / AISI 316L stainless steel. Every part in contact with the material is always stainless steel.

Key BSB station specifications

Lifting capacity: up to 2,000 kg (lifting frame carrying the bag’s 4 loops)
Bag height: up to 2500 mm
Frame: approx. 1500 × 1500 mm; height matched to the application
Hoist beam: 2800 mm long, lifting capacity 1,000 or 2,000 kg
Materials: powder-coated carbon steel; AISI 304 / AISI 316L optional
Parts in contact with the material: always AISI 304 or AISI 316L stainless steel
Docking module: double-ring, dust-tight, with adjustable lid pressure
Options: load cell weighing, dust filter, pneumatic spout closing, automatic bag tensioner, liner tensioner, roller conveyor, disposal of empty bags
Builds: ATEX (dust or gas zone), hygienic FDA / GMP / HACCP

Downloads

BSB station data sheet (PDF) BSB station questionnaire (PDF)

How the bag is loaded

Integrated hoist or fork-lift truck?

The BSB station comes in two loading variants: with an integrated electric chain hoist on an overhead rail, which forms part of the station, or in a version loaded by fork-lift truck. Both use the same frame, lifting frame and docking module.

Criterion	Integrated hoist on an overhead rail	Fork-lift loading
Handling the bag	The operator raises the bag at the push of a button; the trolley guides it along the beam exactly over the docking point	The bag is brought in from above on the forks with a lifting frame
Operator safety	✓ Lifting from the side or the rear of the station, with no crushing risk	Manoeuvring a heavy truck in the working area
Space required	✓ Less, with no manoeuvring area for a truck	An additional manoeuvring area beside the station
Risk of damage	✓ The forks never touch the structure	The frame can be damaged by the forks
Capital cost	Higher (hoist and travelling gear are part of the station price)	Lower, since it uses the plant’s existing equipment
When to choose it	Frequent bag changes, restricted space, high safety requirements	Occasional discharge, with a truck and manoeuvring space available

The higher-safety option

A loading-area enclosure with interlocked doors

Raising the bag and carrying it over the station is the most dangerous moment of the whole operation. A load of as much as two tonnes travels overhead, and loops hung wrongly or damaged fabric can let the bag fall. It is therefore worth enclosing the bag’s whole path in a guard that nobody can enter while it is moving.

The optional loading-area enclosure is a full-height panelled mesh guard with doors that are electromechanically interlocked with the hoist controls. The interlock works both ways: the hoist cannot be started while a door is open, and the doors stay locked until the bag has been set down safely in the docking position. The control pendant is brought outside the guard, so the operator handles the bag from beyond the danger zone. More and more customers ask for this, not least as part of a risk assessment and of the machine’s conformity documentation.

01Doors locked while the bag is raised and travels, with no access beneath a suspended load
02The hoist locked out while a door is open, through the mutual interlock of the two functions
03Controls and the emergency stop outside the guard, within the operator’s reach
04Full-height panels, with the guard shaped to the station’s footprint and to the access to the docking module
05Drives below the discharge point, such as a feeder or conveyor, cut off when a door opens

Big bag discharge station with the optional loading-area enclosure: mesh panels with interlocked doors and the controls brought outside

Flow aids

Massagers, a vibrator or spout stretching?

Bulk solids compact inside the bag during transport and storage, forming bridges and rat-holes that stop the material flowing. We match the flow aid system to the properties of the material, not the other way round.

Pneumatic massagers

Poor flowing materials

+gently massage the material, breaking up bridges and rat-holes
+leave the structure of delicate products intact — granules, flakes, crystals
+transmit no vibration to the structure, which means less noise and lower fatigue loading
+low energy consumption, minimal maintenance

Support table with a vibrator

Moderately flowing materials

+the bag rests on a vibrating table, which fluidises the material
+a simple, proven and inexpensive solution
+sufficient for materials without strong cohesion
+selected individually to suit the product

Spout stretching device

Stretching the bag spout

+tensions the bag spout, keeping the discharge cross-section fully open
+improves flow and empties the bag completely
+improves hygiene, since the spout does not hang into the flow of material
+an automatic tensioner keeps the bag taut throughout emptying
+combined with massagers or a vibrator in one station

Flow aid selection table

Character of the material	Recommended flow aid
Free flowing: granules, granulated sugar, pellets	None, or a support table with a vibrator
Moderately flowing, slightly caking: sugar, salt, groats	Support table with a vibrator, optionally a bag tensioner
Cohesive and dusty: flour, milk powder, pigments, lime	Pneumatic massagers with a spout stretching device
Delicate, easily damaged: flakes, granola, blends	Pneumatic massagers at reduced force, with no vibration
Heavily caked after long storage	Massagers and spout stretching, with a lump breaker below the discharge if needed

The table is a guide. We confirm the final choice on a sample of the actual material.

Not sure which flow aid to choose? We confirm the choice from the properties of the customer’s actual material — particle size, cohesion and tendency to cake — not from catalogue data alone.

Ask about selecting a BSB station

Dust containment

The dust-tight docking module

The heart of the BSB station is the double-ring docking unit. The operator opens the lid, draws the bag spout through the inner ring and closes the lid, forming a dust-tight connection. Only then is the spout opened and the material flows within a closed system.

The pressure of the docking lid is adjustable, which allows the seal to be matched to spouts of different types and sizes. The station can optionally be fitted with dust extraction at the rear and a connection to the plant’s central dust extraction system.

Bag connection: double-ring, dust-tight, with adjustable lid pressure
Spout closing: a pneumatic closing system that allows partial emptying and the storage of part-used bags
Dust extraction: optional extraction at the rear, or a filter integrated into the station; it draws dusty air out of the bag before it is removed
Control of material consumption: optional weighing of the bag on load cells

BSB big bag discharge station: view of the dust-tight docking module with its double-ring docking unit

Integration with the process

Part of a larger system, not a separate machine

The lower frame of the station is adapted to the requirements of the installation, which makes the discharge station an integral link in the process line: from receiving the raw material, through feeding and conveying, to delivering the material into the process. We offer full design support in selecting the interface and the associated equipment.

Discharge into a buffer hopper or reactor

Direct gravity discharge of the material into the process.

Intermediate vessel with a feeder

Controlled delivery by screw, vibratory or belt feeder.

Dilute phase pneumatic conveying

Connection through a rotary valve.

Dense phase pneumatic conveying

Discharge into the sending vessel of a pressure conveying system.

Vacuum conveying

A direct connection to vacuum conveying.

Operation on demand from the process

Discharge started by a level sensor in the receiving hopper or by a signal from the higher-level control system.

Inclined screw conveyor

Mechanical delivery of material to equipment higher up.

Screener or lump breaker

Protection of the process against lumps and foreign bodies right after the discharge: a lump breaker or a check screener.

Industries and typical materials

Applications in key industries

Big bag discharge station at a food industry plant

Food and animal feed

Flour, sugar, starch, milk powder, premixes, feeds. A hygienic build (FDA, HACCP, GMP), easy cleaning and profiled frames that leave nowhere for product to lodge.

Process installation at a chemical plant with big bag discharge

Chemicals

Pigments, resins, plastics granules, salts and fillers. An ATEX build for dust and gas zones, together with the dust-tight docking module.

Discharge of pharmaceutical raw materials in compliance with GMP

Pharmaceuticals

Active substances (APIs) and excipients. A GMP build in AISI 316L steel, surfaces that are easy to clean and validate, and control of raw material consumption by weighing.

Construction and minerals

Cement, lime, gypsum, silica sand, fly ash. A structure that stands up to heavy, abrasive materials. An option to connect to pressure pneumatic conveying.

FAQ

Frequently asked questions

What are the advantages of an integrated hoist over a fork-lift truck?+

An integrated electric chain hoist on an overhead rail does away with manoeuvring a heavy truck in a confined space. The operator raises the bag at the push of a button and the trolley guides it along the beam exactly over the docking point. The bag is lifted from the side or the rear of the station, which improves safety considerably, since there is no crushing risk. The station also needs less working space, because no manoeuvring area for a truck is required, and the hoist removes the risk of the forks damaging the structure.

Why are massagers better than a vibrator in a big bag station?+

Pneumatic massagers gently massage the material inside the bag, breaking up the bridges and rat-holes that form through caking or the cohesion of the powder. Unlike a vibrator they transmit no vibration to the whole structure, which means less noise and less fatigue loading, and they leave the structure of delicate products intact: granules, flakes or crystals. They also use less energy and need minimal maintenance. For moderately flowing materials a support table with a vibrator is enough; we select the solution case by case.

What does a tailored structure mean, and what does it bring?+

Every BSB station is designed from the ground up for one particular application: we match the frame dimensions to the space available and to the size of the bags, choose the flow aid system to suit the material, design the process interface — feeder, buffer hopper, pneumatic conveying — and take account of the requirements of the industry (ATEX, FDA, GMP). The station fits into the existing line without rebuilding its surroundings, and the modular construction allows it to be extended later, for instance with weighing, a dust filter or a roller conveyor.

Does a BSB station allow a bag to be emptied only partly?+

Yes. The optional pneumatic spout closing system allows the bag spout to be closed without dust at any point during discharge. Part of the material can be drawn off, the bag closed and stored for later use, which is useful for precise portions and for discharging different recipe ingredients in sequence. Combined with optional load cell weighing, the operator has full control over how much material is issued.

How is dust contained during discharge?+

Dust is contained by the double-ring docking unit. The bag is raised to the station by the hoist, the operator opens the docking lid, draws the spout through the inner ring and closes the lid, forming a dust-tight connection. Only then is the spout opened and the material flows within a closed system. The lid pressure is adjustable, and the station can optionally have dust extraction at the rear and a connection to the plant’s central dust extraction system.

Why InterProcess

Why choose our solutions?

A tailored structure

Every station designed from the ground up for the customer’s application.

Dust-free handling

A dust-tight docking module with adjustable lid pressure.

Integration with the process

Feeders, pneumatic conveying, weighing, controls.

Experience across many industries

Food, chemicals, pharmaceuticals and construction.

Safety and hygiene

ATEX, FDA, HACCP and GMP builds, and guards with interlocked doors.

Technical support and service

With a fast response, 24/7 if required.

Need a big bag discharge station?

Get in touch and we will design a station matched to your material, your process conditions and the space available, integrated with feeders, conveying and the plant control system.

Send an enquiry