Blow Room Machine
UNIFLOC A 11
Overview of proceeding process
- The control of the bale laydown directly affects the performance of the UNIfloc. The number of assortments determines the maximum production rate.
- The positioning of bales should be performed to obtain consistent mixing and, ultimately, blending of the fibers
- The waste bales and bales of unusual color should be carefully located so as to avoid an undue influence on the consistency of the blend.
- Wherever possible mix the bale location in the laydown:
- Regions of origin should not be separated.
- Fiber properties should be averaged in mini-blends.
- Fiber appearance can indicate troublesome cotton.
- The presence of sticky cotton quickly contaminates the equipment. Care should be taken to control the number of sticky bales in the laydown
Principal features
The UNIfloc is a unique machine designed to remove small tufts of fiber from the top of bales in preparation for optimal cleaning, mixing and blending. The principal features are:
- Production up to 1400 kg/hr with the 2300 mm wide frame feeding from a single laydown.
- Production up to 950 kg/hr with the 1700 mm wide frame.
- Laydown length up to 50 m.
- Up to 130-bales/ laydown on each side
- A laydown “run-in run-out” program to automatically compensate for variations in bale density from top to bottom by adjusting “take off step depth” to maintain a constant production rate.
- A laydown transition program automatically swivels the tower to remove fibers from the new bales during the run-out phase of the old bales (bottom 50 cm).
- i.e. several cycles of - 8 passes on the old bales and 2 passes from the new laydown
- Minimum of 18 bales when feeding cotton or 12 bales of man made fibers are required for satisfactory mixing.
Air requirements
- Transport air from the UNIfloc: 0.85 – 1.20 m3/sec
- Suction in the pipe: 400 Pa (300 mm water)
Undesirable practices:
- Go/stop ratio - Too low. - Production rate and fiber quality affected
- Laying bale parts on top of the new laydown. - Creates chokes and loss of blend control.
- Incorrect location of waste bales. – Waste bales should not be concentrated in one area or located at the end of the laydown.
- Inadequate bale blooming time and the variation in blooming time between bales.
- Warning: Spiral pipes should not be used for fiber transportation because of excessive swirling and fiber entanglement.
- Where fiber passes through a fan, be sure that a “material-handling fan” is used.
Where fiber is transported from one building
to another it is necessary
to insulate the pipes in cold climates,
to prevent condensation in the pipes,
which causes fiber
chokes.
Start up suggestions
The production rate of the UNIfloc should meet the needs of the blowroom. It is very important to balance the delivery rate with the needs of the rest of the line. The effective running time or GO / STOP ratio should be 85% to 90%.
A starting guideline is to use the basic default values and then adjust the settings to optimize the degree of fiber opening and the production rate.
There are four settings that can be adjusted:
Take – Off – Roll penetration Controls tuft size.
For cotton bales normal settings are:
- 2 mm for low production rates with soft bales,
- 3 mm for low production rates with hard bales,
- 3 mm for high production rates with soft bales, and
- 4 mm for high production rates with hard bales.
For bales of man made fibers normal settings are 0 to 2 mm.
Arm lowering steps
Illustration of Roll Penetration
Controls the production rate and is automatically varied during the run-in / run-out program which has to programmed depending upon the variation of bale density.
A guide line of
step depths / production rates for the middle portion
of cotton bales is:
• 1 mm for 200 to 350 Kg/hr
2 mm for 350 to 600 Kg/hr
3 mm for 600 to 900 Kg/hr
4 mm for 800 to 1200 Kg/hr
5 mm for 1000 to 1500 Kg/hr
Arm traverse speed
The traveling
speed of the arm affects
the production speed. Care has to be taken to avoid overloading the opening rollers, which can cause unopened
fiber to be fed resulting in chokes in the transportation system.
Normal traverse speeds are between 9.5 and 10 m/min.
Take off roller speed
The take off roller speed can be adjusted
to feed smaller tufts, but care has to be taken to ensure that neps are not created
or the tufts are not too small. When the tufts are too small the material
is too bulky and is difficult to transport without choking in the pipes.
1500 rpm is normal for cotton
1300 rpm is normal for man-made
fibers
Suggested set up steps to increase
the production rate for cotton.
| Progressive production increase | |||||
Traverse speed | 9.5 m/min | 9.5 m/min | 10.5 m/min | 10.5 m/min | 11 m/min | 11 m/min |
Roller speed | 1600 | 1600 | 1600 | 1600 | 1600 | 1600 |
Roller penetration | 3 mm | 3 mm | 3 mm | 3 mm | 3 mm | 4 mm |
Arm step depth | 3 mm | 4 mm | 4 mm | 5 mm | 5 mm | 5 mm |
Trouble shooting
Production rate too low:
Check and adjust if necessary.
• Arm lowering step distance – too low
• Take-off roll protrusion - too low
• Traverse speed - too low.
• Run-in / run-out not optimized
• Excessive assortments or tower swings.
• Change of material, particularly bulky man made fibers such as acrylics.
Chokes in the fiber transport line:
§ Remove loose fiber from the tops of the laydown and pack it between the bales.
§ Check the air speed
in the different points in the line.
§
Check the condition of pipes. Seams, joints, surfaces
and bends can cause fiber chokes.
§
Check the condition of the fan inside the UNIfloc. All material, including
trash, pass through this fan.
§ Ensure correct
fan speeds.
§ Reduce the penetration of the take-off
roll.
§ If chokes occur after the fiber has passed from one building to another, check to see if condensation is occurring in the pipes between the buildings. Insulation
may be necessary in cold climates.
Excessive neps in the opened material:
§
Check the airflow from the UNIfloc.
Insufficient airflow can cause an increase in the nep level.
§
Check nep levels throughout the system to determine where the change
in nep level occurs.
§ Throughout the laydown and look for problematic bales,
§ Take several
samples immediately after
the UNIfloc,
§
Take several samples at the entry to the machine following
the UNIfloc.
§ Check the condition of the teeth on the take-off roll. If damaged they should be replaced.
If worn or rounded they should be replaced or sharpened if the replacement parts are not available.
§ Reduce the take-off roll speed.
Trash in the opened material is too high:
§ Check the go/stop ratio and correct
if not close to 85%.
§
Increase take-off
roll speed to reduce tuft size.*
§ Reduce the penetration of the take-off roll to
reduce tuft size.*
§ Reduce traverse
speed.
Note: Some of the above actions may reduce the production rate. Production rate of the UNIfloc should be checked for several
shifts. One check is not enough.
..................................................
UNICLEAN B-11
General Information
The UNIclean is an outgrowth of Reiter’s experience in removing trash from cotton while it is airborne as the first cleaning point in the blowroom and is consistent with the cleaning philosophy:
- a minimum number of cleaning positions
- maximum working efficiency
- optimum fiber preservation
- high raw material yield
Removal of foreign matter during the first cleaning
stage in the blowroom.
UNIclean B 11
Principal Features
Production up to 1'200 kg/h (2'600 lbs/hr)
- Selective trash removal
- High dedusting effect
- Gentle fiber treatment
- VarioSet for easy operation
- Change waste amount in a range of 1:10
Mode of operation
In contrast to conventional pre-cleaners, i.e. single-cylinder cleaners or horizontal cleaners, material transport inside the UNIclean takes place mechanically by means of special pins, independently of the conveying air. The raw material is forced over the cleaning grid bars where trash is removed and an integrated de-dusting unit to remove fine particles.
The waste is collected
inside the machine
and is automatically released to the waste suction system.
Since dust and sand cause considerable problems in the spinning operations, the UNIclean has been equipped
with an integrated dedusting unit. Dust, sand, some pepper trash and fiber fragments
are separated from the cotton by a perforated plate and released
to the filter system. Only some 0.5 cubic m/s of dust laden exhaust air has to be removed in the dedusting function.
To control
the cleaning action of the UNIclean both the “cleaning
intensity” and the “waste rate” have to be programmed into the machine.
The cleaning intensity
controls both the speed of the drum and a compensatory setting
of the grid bars. Increasing the “cleaning intensity”
increases the trash removal. The “waste rate” changes the grid angle to remove more or less material.
These setting are made on the machine control panel or in the VarioSet
program if it is available.
Fiber transportation
The material is blown to the UNIclean, and is circulated seven times inside the machine by the tines on the drum. The cleaned fiber is sucked from the machine by the transportation fan. Careful adjustment of the airflow is essential to the effective operation of the machine.
Part of the feed transport air is sucked through the perforated plate by the dust waste fan. Fine particles are removed and discharged to the filter
system.
The quantity
of air required to transport
the fiber to the next machine exceeds
that amount passing
through the machine.
To minimize
the volume of air passing through the machine, a supplementary air inlet is provided to allow extra air to be sucked into the system as needed.
Cleaning process
As the fibers enter the machine they are carried in a circular motion by the tines.
The fibers are directed
by the guide plates to make seven revolutions before leaving the machine. In each revolution the fibers pass the grid bars and the perforated plate.
The “Cleaning
Intensity” can be adjusted step-less,
to changing the rotational speed of the drum. The adjustment can be done while the machine is running. Additionally, the angle of the grid bars is automatically changed
in combination with the speed.
The
“Waste rate” can be varied by changing the grid bar angle with an electrically controlled cylinder. The settings of the cleaning
intensity and waste rate can be recalled
and used again at a later date.
Cleaning intensity
|
Production |
Setting |
Drum speed |
|
Up to 1'200 kg/h |
0.0 (low) |
480 rpm |
|
Step-less adjustment to |
||
|
1.0 (high) |
960 rpm |
|
Relative waste rate
Setting «1» (Low): Setting «10» (High):
Grid closed, lowest waste rate Grid open, highest waste rate
dark waste composition light-colored waste composition
Cleaning characteristic diagram
The typical
amount of waste to be removed by varying the settings is shown in the following chart. The influence of the cleaning intensity
setting increases as the waste rate is increased.
As a guideline, the following table gives values of the cleaning intensity
and the waste rate according
to the trash content of the cotton
to be cleaned.
|
Trash in cotton |
Applications |
Cleaning intensity |
Waste rate |
|
0.5 to 2,0 % |
Clean cotton fine
combed yarns |
0.5 to 0.9 |
0.5 – 0.8 % |
|
1.0 to 3.5% |
Ring spun carded yarns |
0.6 to 0.9 |
0.8 – 1.5 % |
|
1.5 to 4.5% |
Rotor yarns Ne 10/1 to 24/1 |
0.7 to 0.9 |
1.0 – 2.0 % |
|
3.0 to 6.0% and more |
Rotor yarns coarse counts |
0.2 to 0.7 |
1.5 – 4.0 % |
Waste disposal
The waste is removed
periodically through the airlock roller.
The interval is determined by the waste transport system.
The waste extraction
roll incorporates an airlock, which seals the waste chamber to prevent
Determining the amount of waste
o determine the amount of waste extracted, the waste has to be removed by hand, weighed and compared with the production rate to calculate waste %.
Follow the instructions on how to isolate the trash chamber
from the suction system and manually operate the air lock roller to remove
the trash
Take at least three (3) tests, each of at least half an hour.
(For a provisional test, collect the waste for more than one complete
cycle of the UNIfloc.) Record the running
time of each test.
Calculate the production (kg) during the test time =
Carding production rate from the line kg/h x test time in min 60
Waste % = Amount of waste removed x 100 ÷ Production during test + waste
Note:
The system should be operating with an acceptable
stop/go ratio otherwise
when the system is optimized
the actual waste % will vary from the tested value.
Stop/go ratio = Running time of the UNIfloc (operating hours counter)
Actual time
Trouble shooting
Neps too high in the material downstream
Neps can be created at many points. Carefully check the nep levels throughout the system.
- Immediately after the UNIfloc.
- At the entry to the UNIclean.
- At the exit of the UNIclean
- At the entry to the UNImix.
- Check and correct the volume and speed of the airflow in the system.
- Check the condition of the fans
- Frequently a nep increase occurs in the transportation pipes because of,
- Rough pipe surfaces,
- Tagging and roping,
- Rolling of stock,
- Bad joints
Trash too high after the UNIclean
- First check the cleaning effectiveness of the UNIclean. Normal levels depend upon the type of cotton and the amount of trash in the cotton.
- Check and correct the stop/go ratio of the UNIfloc. If it is too low then the instantaneous fiber flow rate through the UNIclean will be too high.
- Adjust the cleaning settings of the UNIclean.
- Check to see if there is trash being pulled back from the waste chamber through the grid bars and into the cotton. If so correct, 1) the airflow through the UNIclean or, 2) the trash extraction system.
- Check the bale laydown to see if there is a grouping of bales with a high level of trash or waste. This produces surges of material with high trash content that can appear to be a problem with the UNIclean. Distribute the bales throughout the laydown.
Blockages in the system
- Incorrect airflow in the system – check air speed and volume.
- A backpressure from the UNImix can occur if it is too full.
- Check the air pressure switch on the UNIfloc.
- Check the condition of the fiber transport fans, they could be loaded, damaged or not running at the correct speed.
- Be sure that the fan belts are in good order and tight.
- The air opening for the supplementary air may not be set correctly and allowing excessive false air into the pipes.
- The pipes may be damaged or contaminated causing the fibers to stick and choke. Long transportation distances and/or multiple pipe bends are problematic.
- Check the stop/go ratio of the UNIfloc. If it is too low, then the actual material flow rate can overload the system and cause chokes. It is important to maintain a ratio of 85 to 90%
- Check the performance and settings of the UNIfloc to be sure that it is not over feeding un-opened, large pieces, of cotton from soft bales or bale tops.
Waste not being removed from the trash chamber
The waste extraction roll does not turn, the drive system may be jammed,
- The control from the filter system may be out of order,
- The filter may be overloaded and a back pressure built up,
- Waste exhaust fan may not be operating correctly.
- Note: If a damaged waste extraction roll has to be replaced: the plant must continue to operate without one, using continuous waste removal, it is necessary to close the grid bars to prevent excessive fiber being pulled out with the waste. This is only a temporary measure.
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