The BATEMAN Pneumo-Drier full-scale test facility, also capable of all modes of pneumatic conveying.

The BATEMAN Pneumo-Drier dries a particulate solid while conveying it. This is achieved simply by introducing the wet particulate material into a pneumatic-conveying system driven by heated air.

The BATEMAN Pneumo-Drier

• Controls drying - handles moisture levels of up to 25 %, depending upon the nature of the material. All parameters are monitored continually to ensure effective and efficient drying.
• Saves cost - a simple, robust system with few components, it replaces the dual systems used currently to dry and transport the material.
• Enhances security - securely encloses the material being conveyed from time of entry until delivery.
• Is compact and flexible - requires far less headroom than existing systems, whether it is a new or replacement system.
• Is environmentally friendly - completely encloses the conveyed product, thus preventing contamination of either the product or the surrounds.
• Has optimum availability - requires minimal maintenance.
• Specifications - the Pneumo-Drier can convey up to 20 tonne/h and, depending on the thermal properties of the material, will dry at up to 350° C.

Wet material from dewatering bins is discharged into the BATEMAN Pneumo-Drier
through twin vertical surge hoppers mounted on load cells that interlock with
pneumatically-actuated
pinch valves.

A small amount of blower discharge air is bled off to the feeder sub-system, to protect the rubber pinch valves and compensators from over heating, and then re-enters the system via the feeding tee.

A vibrating-tube feeder then batch-feeds the material through the feeding tee into the
conveyor pipe.

The material is dried while being transported to the knockout bin, where it cools as it free-falls in a large volume of low-velocity secondary air.

The BATEMAN Pneumo-Drier system installed recently at an Anglo Platinum mine near Rustenburg is the first full scale plant to be used in the platinum industry to simultaneously convey and dry particulate solids. With a total conveying capacity of 96 t/h it is, to date, the largest Pneumo-Drier system to be supplied by BATEMAN.

The order for the system was placed by Hatch Africa Project Managers following a successful pilot plant trial at another site. The system comprises two separate trains, each feeding 48 t/h of material to the converter-slag and the furnace-matte plants. Each train contains two parallel BATEMAN Pneumo-Driers with a capacity of 24 t/h. With parallel units, production losses will be minimised if either one fails. Approximately 4 MW of installed power is used to reduce the moisture content of the 96 t/h feed of platinum matte and slag from 15 % to zero.

The BATEMAN Pneumo-Drier dries a wet particulate solid while conveying it along a pneumatic-conveying system driven by air heated up to 350°C, depending upon the properties of the solid. The material is enclosed from the time of entry until rapid delivery, with few handling stages, enhancing product security and preventing contamination of either the product or the surrounds.

A Roots-type positive displacement blower with variable speed drive propels the conveying / drying air into the inline heater (electrical or heat exchanger) and to the feeding tee. A small amount of blower discharge air is bled off to the feeder sub-system, to protect the rubber pinch valves and compensators from over heating, and then re-enters the system via the feeding tee.

The wet material from the dewatering bins is discharged into the Pneumo-Drier through twin vertical-surge hoppers mounted on load cells that interlock with pneumatically-actuated pinch valves. This arrangement provides the necessary airlock between system overpressure and ambient conditions. A vibrating-tube feeder then batch-feeds the material through the feeding tee into the conveyor pipe where it is dried while being transported to the knockout bin, where it cools as it free-falls in a large volume of low velocity secondary (ambient) air. The latter is extracted from the bin into either a dust-filtration system or wet / dry-scrubber system, while the dry material is conveyed pneumatically to the storage silos.

Used predominantly in the diamond industry to handle kimberlite (diamondiferous ore), alluvial diamond ore and marine silica, the BATEMAN Pneumo Drier has also successfully conveyed and dried other materials such as coal, foundry sands, salt and crushed rubber.

In many instances it has replaced traditional rotary, infrared and fluidised-bed driers because of its capital, operating-cost and downtime advantages. It is simple, robust and compact, requiring less headroom than conventional drying systems. The flexibility of the pipe routing allows for easy retrofitting into the existing establishments. Continuous on-line temperature monitoring and accurate product dosage maintain system efficiency.

 

BATEMAN has recently supplied several systems for conveying diamonds and diamondiferous concentrate to mines in Botswana. At Jwaneng Diamond Mine two Pneumo-driers have been installed to handle wet recovery concentrate at a rate of 20 tonne/h and bulk sampling concentrate at a rate of 1 tonne/h.

Material containing 10 % moisture is fed via tubular feeders and in-line heaters of propriety design into these Pneumo-driers. The conveyors are designed for optimum product drying within the conveying lines and ensure trouble-free storage and discharge. This has been proven to be by far the most efficient product drying process and is unique in that it permits the possibility of drying a particulate material while it is being conveyed.

Two positive pressure pneumatic conveying systems have also been supplied to Jwaneng for handling X-ray machine waste discharge and sort-house products. BATEMAN's long involvement in the diamond industry has enabled it to optimise this type of conveying system.

At Orapa Diamond Mine, some 400km north of Jwaneng, BATEMAN's expertise in turnkey-engineered vacuum conveying systems can be seen in two such applications which handle incoming plant concentrate. The advantage of this type of system is its simplicity and reduced operator involvement.

For the past decade BATEMAN has successfully applied its in-house pneumatic conveying technology to diamondiferous materials and has installed systems throughout sub-Sarahan Africa and as far afield as Canada. This in-house expertise covers both positive and negative pressure pneumatic conveying as well as the patented Pneumo-drier; more than ten of the latter installations are already operating successfully in the diamond processing industry.

Material is fed through a tube feeder into a typical BATEMAN dilute-phase pneumatic conveyor. Security is high and dust release minimal, due to a fully sealed and contained system.

 
Pressure and vacuum systems

BATEMAN systems collect and discharge granular material from one or many points and are particularly economic and efficient for conveying relatively low tonnages over short routes.

• Use pressure systems for multi-discharge point-transfer systems.
• Use vacuum systems for multi-collection point-transfer systems.
• Convey food, plastics, chemicals, powders, wood chip, sawdust, tobacco, cement, scrap metal, ores, etc.

BATEMAN dilute-phase conveyors

• Are hygienic - vital for food products.
• Have optimum availability - require minimal maintenance.
• Specifications:
  • throughputs from a few kilogrammes per hour to over 50 tonne/h
  • handle particle sizes from 1 mm to 40 mm
  • conveying routes may be horizontal, vertical and tortuous, from a few metres to
    over 200 m
  • the propelling force is provided by Roots-type blowers;
    • pressure systems typically use a maximum pressure of 60 kPa (g)
    • vacuum systems typically use a maximum vacuum of -40 kPa (g)

 

A Cyclonaire pneumatic bulk-conveying system.

 
These systems provide the optimum solution for the medium-rate transfer of aeratable abrasive or friable materials.

• Specifications:
  • capacities of up to 80 tonne/h are possible through various modes of loading and unloading
  • air is delivered via a Roots-type blower at pressures up to 120 kPa (g).

 

 

Compressed air is fed from the booster line into the conveying line via adjustable injectors

These systems utilise the low-velocity and high-pressure conditions ideal for the high-rate conveying of aeratable or non-aeratable abrasive or friable powdered materials.

BATEMAN boosted dense-phase pneumatic conveyors

• Minimise pipeline wear
  - due to the ultra-low conveying velocities.
• Specifications:
  • capacities of a few tonne/h to more than 400 tonne/h can be achieved through either top discharge or bottom discharge conveyor vessels
  • distances of up to 2 kilometres can be achieved utilising the 'Cyclonaire' injector technology
  • the motive force is a high-pressure, low-volume air supply. Pressures are typically in the range of 100 kPa up to 600 kPa.

Cyclonaire Injectors

Injectors are fitted to BATEMAN dense-phase pneumatic-conveying systems handling powdered materials which tend to pack under pressure. The small particle size of powdered material usually prevents any air from flowing through slugs of such a material in the pipeline.

When the length of a 'non-porous' slug becomes too long, the friction against the pipe wall becomes greater than the available force (pressure) pushing it along the pipe. At this point the slug becomes a plug and blocks the pipe.

The injectors control slug lengths in the pipe, preventing blockages and making it possible to re-start the flow of material when the line is full. They are typically set up to operate at 120 kPa above the conveying-line pressure.

 

 

Cross-section through a
BATCAT capsule.

A BATCAT docking station

BATEMAN's high-security capsule / tube-mail system gently transports valuable and friable materials.
Use the BATCAT to transport diamonds, diamond and precious metal concentrates, pharmaceuticals, chemical products and other precious materials.

The BATEMAN BATCAT

• Has high levels of security:
  
  
  • no direct personnel access to transported material during commissioning, operation or maintenance
  • fully automated, remotely-controlled system, robust and tamper resistant
  • self-cleaning operation, with no material hang-up or spillage at transfer points.
    
    
• Transports gently and caringly:
  
  
  • minimal inter-particle abrasion or impact during encapsulated point-to-point transport
  • gravity drops of no more than 100 mm at transfer points.
    
    
• Is versatile - adaptable to virtually any project size.