A simple clean and energy efficient microwave process that evenly heats the whole bale to rapidly soften and expand compressed wool. Microwaved bales retain their softness much much longer than conventionally steam heated bales.

Microwaved wool is easier to open, has greatly reduced fibre breakage, has increase fibre length,better whiteness and less noilage.

Performance

The system performance per hour is indicated below and represents approximate values only, based upon a bale weight of 180kg. The presence of water will adversely impact performance.

System Performance(100kW)

Typical System Specifications

The wool bale processor consists of five major components;

1. Microwave generator(100kW)
2. Microwave cavity(designed to suit Aussie tri paks)
3. Entry conveyor (900 x 5500)
4. Weigh conveyor(900 x 1800)
5. Exit conveyor (900 x 5500)

Operation

Wool bales (single, double, or tripaks) are loaded manually via a fork lift onto the entry conveyor. Each bale is then indexed automatically to the weigh conveyor where the weight is used to determine the microwave heating time.

After weighing the bale automatically moves into the cavity and is heated to the required temperature. On completion of the heating cycle, the bale(s) is ejected from the cavity onto the exit conveyor ready for the scouring line. Bale handling functions are controlled by the use of standard industrial photo electric sensors.

The microwave generator provides the electromagnetic energy and houses most of the control devices associated with the system. Microwaves produced inside the generator are propagated along the wave guide and then into the cavity. Energy entering the cavity is then absorbed deep into the wool bale(s) causing an increase in temperature. If the bale is over heated, some carbonization(10-20grams) can occur around the steel clips, this would be subsequently removed by scouring.

Bale temperature is determined by the level of microwave power(kW) and the heating time(sec). The maximum power is dependant on the system size and is easily controlled from the front panel by adjusting the knob labeled "POWER".

The heating time is a function of the bale weight and can be scaled by adjusting the heating time multiplier (MUL).

Heating Time(sec) = bale weight(kg)x(MUL)

Generator

The generator is a stand alone device containing the magnetron, power supply, circulator and all control functions associated with the system operation. The generator can be located up to 30m away from the cavity and is linked to the cavity by wave guide and multi-core cable. It is the customers responsibility to provide a dust and contaminant free air supply to the generator.

Technical Data:

Microwave power 100kW
Motors/controls/fans 5kW
Total power consumption 133kW +/- 4%
Sources 1 off @ 100kW
Frequency 915MHz +/- 10MHz
Circulator/dummy load YES
Supply voltage 380V
Cooling water required(distilled) 20 l/min
Cabinet mild steel
Wave guide linking to cavity aluminum( 7 meters only)

Controls

All system control functions such as heating time, cycle startup and meter readings are located on an easily accessible operator friendly control panel. The control panel includes;
- key switch
- start button
- stop button
- run light
- power control(5 - 100kW)
- heat time multiplier
- E/stop
- fault indication

The system will also include a remote panel from which machine operation can be controlled.

The system uses an Allen-Bradley PLC(SLC 500 series) with a RS Linx communication package allowing seamless connection to PLC's via direct or modem connection. RS Linx will also allow remote program modification or fault finding with a minimum of effort or disruption.

Safety

In order to ensure operator safety, each door frame is fitted with a microwave choke ensuring international occupational safety limits for leakage radiation are maintained. The Wool Bale Warmer complies with Australian standard AS2772.1 -1998 "Maximum Exposure levels - 100kHz to 300GHz " and the European Committee for Electromechanical Standardisation(CENELEC) pre-standard ENV 50166-2

Machine safety is maintained by the following safety circuits and appear as fault indicators on the front panel;

- AIR monitors the flow of cooling air to the magnetron,
- WATER monitors the flow and temperature of cooling water to the magnetron
- DOORS microwaves disabled unless both doors are closed,
- E/STOP will illuminate if emergency stop is activated,
- ARC DETECT detects internal magnetron or inverter arcing,
- CONT FAULT indicates a problem within the inverters,
- P.S TEMP indicates an over temperature condition within the generator,
- AUX indicates smoke detected within the cavity,

Cavity

The cavity is capable of accommodating Aussie tri paks up to 700kg in weight. The chain conveyor inside the cavity will oscillate the bale during the heating cycle to ensure heating is homogeneous throughout. Temperature uniformity is further improved by equally distributing the available power through a minimum of four input ports.

Conveyors

The system comprises three external chain type conveyors (entry, weigh and exit) individual motor gearbox drives per conveyor.