The Walair 4-way Drum-separator is separating one waste stream in 4 waste streams, a heavy, middle and light and very light fraction.
Not many people know that Walair is producing a 4-way Drum separator.
This is the big brother of our 3-way Drum separator and is made with 3 drum separators. With our 4-way Drum separator it is possible to separate one waste stream in four partial waste flows. A heavy, a middle weight fraction, a light and a very light stream
For example stones, wood, paper, plastic, light paper and foils.
Frequently the Walair 4 way separator is used for processing Alternative Fuels (RDF).
But the Walair 4-way Drum separator can be used for several waste streams. Frequently the light and very ligt waste is transported to secondary shredders. The shredders are feeded directly and the feeding amount of light waste is regulated by the drum separators.
RDF is a fuel that is normally produced of waste with high calorific value. The original waste comes from households, industry and commerce and is processed for energy extraction; it is meant for co-incineration plants and replaces standard fuels (e.g. coal) in production plants for cement, power plants or other co-incineration plants.
In order to produce Refuse Derived Fuels with defined qualities and guaranteed specifications, multi-level processing is required that mainly includes the following stages:
1. Primary shredding
2. Separation of extraneous material by Walair Drum separators
3. Secondary shredding
4. Finalization (e.g. through screen basket)
Processing of RDF usually takes place in the following RDF value categories:
low calorific RDF
average calorific RDF
high calorific RDF
The 4 way Drum separator is made in several width sizes the fan separators are made in capacities from 20.000m3/h till 45.000 m3/h.
The three separating drums are made in a diameter from 1000 mm and 650 mm.
The conveyor width from the unit are made from 1200 mm till 2000 mm. The unit can handle waste streams until max. 70 tons/hour (250 kg/m3).
Working principle of the 4-way Drum separator
After the screen with discharge conveyor the input fraction will be imported to a fast running speedup conveyor.
The conveyor is adjustable in a horizontal and vertical position and in an angle.
We advise to supply the conveyor with a frequency regulator, so the speed can be adjusted between 1 – 2.2 m/sec.
Below the conveyor a blow mouth is installed. The blow mouth is adjustable in a horizontal and vertical position and in an angle. To adjust the air flow, the blow mouth is executed with 2 air regulation valves and can be adjusted in angle.
The speedup conveyor is air tide connected to a separation room with a rotating heavy metal drum with a diameter of 1000 mm.In the separation room, using the blowing capacity of the blow mouth and the suction capacity above the separating drum, the heavy fraction is removed from the middle heavy and the light fraction.
Both the inlet, as the distance to the drum till the discharge chute to the expansion room, can be adjusted in height and angle.Along the front of the drum, the heavy fraction is, by means of a chute, discharged to a discharge conveyor.
In the separation room the middle heavy and the light fraction is blown and extracted over the drum and discharged into the first expansion room.
In this expansion room the air is separated from the middle heavy and the light fraction.
Under the expansion room a discharge conveyor transports the middle heavy and the light fraction to a second drum separator.
This separator also consists of a separation drum and a blow mouth .
The middle heavy fraction is, by means of a chute, discharged to a discharge conveyor .
The light fraction is separated in the separation room and blown and extracted over the drum and discharged in the second expansion room. Below this sedimentation room a discharge conveyor transports the light fraction to a third drum separator.
The light fraction is, by means of a chute, discharged to a discharge conveyor . The very light fraction is separated in the separation room and blown and extracted over the drum and discharged in the third expansion room Below this expansieonroom a discharge conveyor transports the very light fraction to the outlet of the separator
To create a suction flow above three the separation drum, the expansion rooms are executed with 2 extraction ducts which are, by means of two suction ducts connected to three fan separators. One fan for each separator The fans extract for 100% the air out of the two expansion rooms.
In the fans the air is separated in an air dust flow of approx. ± 20%, and a blow air flow of ± 80%.
With the blow air flow the fraction is pushed against and over the separation drum.
The air dust flow (20%), containing the dust, is discharged to the dust filter.
The three fan separators are executed with two regulation valves. These valves determine the amount of air to the blow mouth and the amount of air which must be discharged to the dust filter.
We advise to supply the fan separators with frequency regulators, so the airspeed can be adjusted.
By using these possibilities and the adjustments on the speed-up conveyor of the drumseparator and adjustment possibilities on the second drumseparator, the 4-way separator can easily be adjusted for different input flows and fraction sizes.
The special fan separators allow the installation to work with a relatively small dust filter, due to the circulation of ± 80% of the total air capacity.