M.N. MOSKOVSKIY
MODELING OF THE  FRACTIONATION THE STRAW HEAP  IN THE ASPIRATION CHAMBER

 

During a combine harvesting we have a significant amount of a straw, which is a potential raw material for the production the  bedding material (litter) in the livestock and the  poultry. Fractionation with the air flow is one of the main processes of the producing litter.
The aim of this research is to develop a new math model of the separation straw heap in the aspiration chamber by using the air flow. We consider a vertical aspiration canal ACPK with given geometric characteristics: wide BK, depth SK  (Figure 1a). Supply  of  the straw heap is carried out with a known or defined   probabilities density  on the width of the input side and  on the depth  [1].We consider an arbitrarily located (below the entry of the granular material in AcPK) section ABC with the limited size of the chamber (Fig.1b).

              

                              а)                                    b)

Figure. 1. Vertical aspiration  chamber
a- diagram of the input material, b-section ABCD,  ground mik, in the vertical aspiration canal  with the width BK and depth SK 


We define the air flow speed  by the using the triple integral of the function φ (x, y, z) in accordance with the adopted assumptions [1] and locations of a rectangular ground  ik-profile section (A ≤l≤J, J≤b≤D) on the plane xOy, coinciding with the ground of section ABCD of the aspiration chamber.

(1)

For every ik-ground bounded by the size of lb, we defined supply   of the some straw heap containing different fractional xj-components. The value of the specified delivery site is determined by the probability density separation of the filing of cross-sectional area of  the size of the aspiration chamber Q, the coordinate H-section under consideration, the way the input material K.
                                                                                 (2)
There  is post  the straw heap with   q1, q2, … ,qj of the j-th component for every ik-ground  (i = 1,2,3, ..., j) with BK the width of the aspiration chamber, that we defined by  a probability density separation  of the random.

 The values of  the Q and Bk the width of the chamber, and the separation of the j-th component in  Sk the depth of chamber for each i-th site (i = 1, 2, 3, ..., N)  defined by the density distribution of the probability of filing for a depth of i-th site. Completeness of the  passage  η of the n-th component of the heterogeneous granular medium in the purified fraction of  the straw on the mik-th ground  depends on the average operating speed of the air flow at the  ground.  

Speed depend on the probability P (V) Jn a random separation of probabilistic sense, the statistic  value for the n-th component in the J-th class of values  of variable V   , J = 12, 23, ..., (i-1) i, (Fig. 2)   and  defined by probability density function Λn(V)  characteristic Vb light components, and supply qin, qi  of the n-th and all n-x components mik-th ground, the laws Rηn (V) complete separation of light n-th component of the granular medium, depending on their velocities fall velocity, the probability density (Fig. 2):

 

 

Figure.  2.  Graphics dependence of the completeness Rηn (V)  passage and release   NηnP (V) passage  of the n-th component   through   mik-th   cross section   depending on the height H of the location of the cross section and the velocities  Vn   components at a constant average speed of air flow   

 

The found regularities and estimates of numerical characteristics of size quantities of fission sign ik-th component of the straw heap  at the ground of  the aspiration chamber allow to define new numeric characteristics of the final material after air separation. These numerical characteristics account the specific   the numerical characteristics of the numerical velocity fс.в()i; Мс.в()i; σс.в()i  and the known patterns of functioning aspiration chamber during  applying of the straw heap [2].

REFERENCES

1.                 Моделирование процесса фракционирования соломистого вороха в аспирационном пневмоканале с вероятностными характеристиками распределения соломистого вороха и воздушного потока. Инженерный Вестник Дона.- №1 -2011. //www.ivdon.ru/magazine/latest/n1y2011/349/]

2.                 Московский М. Н. Интенсификация процесса сепарации семян зерновых в зерноочистительных агрегатах : дис… канд. техн. наук: 05.20.01 – Технологии и средства механизации сельского хозяйства / М. Н. Московский ; ДГТУ.- Ростов н/Д, 2005. –с.47-60