An analysis of the efficiency of the ginning of cotton fibers with two saw cylinders has been carried out. In comparison to a one-cylinder machine, the 2 cylinder approach can help to preserve the natural characteristics of cotton fiber and seeds. This technology allows economizing electricity and decreasing damage to fiber and also increases the productivity of the machine.
The effective analysis has been held on efficiency of removing the fibers from the teeth of two cylindrical saw through a brush drum. By doing this, the natural properties of cotton fibers are preserved.
Brush drums are installed for removing fibers stuck on the saw surface while coming out of the grid bar net. The drum should provide complete collection of fibers from the saw teeth without damaging seeds or saw teeth in case hard subjects appear in the zone [
The efficiency of a brush drum is characterized by the quantity of raw cotton which is collected from the surface of the saw cylinder and is estimated with a collection coefficient.
where is the quantity of raw cotton collected from the brush drum and the quantity of raw cotton remaining on the surface of the saw. Intensity of processing the surface of saw cylinder by the brush drum is characterized the coefficient of influence [
where: z—quantity of collecting sections on the brush drum;—area of the work surface of saw cylinder with a section of brush drum;—length of the circle of saw cylinder, when the brush drum rotate once.
The greater the indicator, the higher the efficiency of the brush drum.
According to Figures 1 and 2, the length of bow of the first saw drum equals
the length of bow of the second saw drum equals where:—radius of the saw cylinder;—angle speed of saw cylinder 1;—type of time quantity of saw cylinder when turned to the angle;
where—radius of the saw cylinder;—ngle speed of saw cylinder 2;—type of time quantity of saw cylinder when turned to the angle;
where:—angle speed of brush drum;—angle speed of saw cylinder 2.
Then,
а = 4 - 5 mm—thickness of the layer of raw cotton;
L = r1 + R2—distance between the centers of saw and brush drums;
The size of the angles & determined in
From which
where: R1—radius of saw drum taking into account the thickness of the layer of coming out raw cotton.
The length of the bow of the saw cylinder circle, made per rotation of brush drum.
where,
—time of one rotation of the brush drum.
So as Then
Putting the value of S0 and in formula (2) we get,
For non-stop removal of fibers of raw cotton from the saw surface it is necessary that
Changing the angle speeds in the formula corresponding to circumferential speeds and transforming them, we get the formulas of the relation of the speeds of the brush and the saw drum, which correlates all kinetic elements of the working unit of the drum brush [
In known values of the size it is possible to define the required quantity of the planks of brush drum stemming from the condition that in rotating the saw drum to the angle of brush drum for collecting fibers, located in point A, should rotate to the angle of. So as the rotation time of saw drum to the angle of and the rotation time of brush drum are equal, it can be written
Or
In
α is an indication of angle of section between two brush.
Required quantity of planks on brush drum
In
Efficiency of brush drum increases with the increase in
the coefficient of influence, which depends on the diameter and surrounding speeds of brush and saw drums. By the increase of the speed of brush drum or increase in its diameter the coefficient of influence increases, and with the decrease of the speed of saw drum fiber collecting surface increases. In
In
In
Based on two-saw cylinder the quantity of taking a fiber increases and this leads to the improvement of productivity. The fiber taken from a first—saw cylinder through brush drum touches the next fiber in the teeth of second—saw cylinder and in this case, the fiber is taken carefully through brush drum preserving its natural features with no damage to it. This creates the opportunity of getting a fiber in good quality.
In
The influential coefficiency—is received for brush drum working in normal work regime. When there is an increase of humidity of cotton, it is necessary to increase the influential coefficiency. If it is w = 6%,
is received. If it is w = 8%, then is received.
According to the indication of graph in
In
Using the indication of
In conclusion, we have got the optimal result of the least medium and high level of productivity of work and this is indicated in schedule.