Local experimental studies of the fertilizer uptake process into suction pipelines of pumping stations with a jet apparatus

Determination of the total energy in the suction pipeline of a four-component mixer of fertilizers and water in an experimental way, for the possibility of its use in various schemes of cropsirrigation has been performed. Materials and methods: The research was carried out at an operating pumping station LLC “Rassvet” Kuibyshevsky district of Rostov region on a specially made installation using calibrated control and measuring devices in accordance with GOST 24028-80 “Research tests”. The experimental results’ processing was carried out according to the recommendations of V.N. Voznesensky on the theory of experiment planning. The experiments were carried out in two stages, the first to determine the factors influencedegree: В1– mixer vacuum value, accepted values 0÷9 m, В2 – vacuum value in the suction pipe of a centrifugal pump, assumed values 0÷5 m, H1 – the head of the jet pump, taken within 0÷25 m, at full energy in the suction pipe of the mixerS (pressure + velocity head), which subsequently determined all the hydraulic parameters of the mixer suction line (pipe diameters, distance of mixture transportation, head loss in the suction pipeline. According to the first stageresults, the influencedegree of the factors on the criterion was determined - the mixer head is 66.37%, the mixer head mixer pipeline 26.32%, mixer vacuum 7.3% The second stage was carried out with the two most significant factors, the mixer head HIand vacuum in the suction pipe of the pump В2. Based on the results of the second group of experiments, an equation, the analysis of which made it possible to determine the value of the variationstudied intervals criterion was obtained.


Introduction
Method of fertilizing using mobile transport (Table 1). Each of the above-mentioned methods has its own advantages and disadvantages. In this paper, two methods of fertilization using an annular four-component two-surface jet mixer (Figure 3) are considered as the most progressive and economical mixer that has been pre-tested during irrigation process [3].     Both methods shown in the diagrams were used at pumping stations with a positive suction height and with forced introduction of fertilizers using a jet mixer capable of creating a vacuum in the suction zone up to 9 m and a pressure in the delivery zone up to 20 m.In addition, when using a jet mixer, it is possible to regulate the fertilizer supply.

Materials and methods
To identify possible values of the mixer feeds, the experiments at a pumping station LLC "Rassvet" using the theory of experiment planning were carried out [4] according to the scheme ( Figure 8) for determining the potential energy (referred to the unit of weight and expressed in meters of pumped liquid -water) as factors were used: is the amount of vacuum in the mixer housing, the accepted values is the value of vacuum in the suction pipe of the centrifugal pump, taken within is the head of the jet pump, taken within m 20 0  . The potential energy per unit weight of the pumped liquid in meters in the suction line of the jet mixer was determined as a criterion (see Figure 8) , by which all the hydraulic parameters of the suction line of the jet mixer were subsequently determined. A centrifugal pump was used to supply working water to the mixer D 320-70. The pressureflow characteristic is shown in Figure 9.  In field studies, two groups of experiments were carried out. The first is to determine the influence degree of each factor by the amount of energy S in the suction pipe of the mixer. For research at the first stage, a threefactor plan was adopted. Factors and intervals of variation are shown in Table 1 and assigned based on a previous literature review [5,6,7,8,9].  Table 2.    (   3  2  23  3  1  13  2  1  12   2  3  33   2  2  22   2  1  11   2  3  33   2  2  22   2  1  11  3  3  2  2  1 1 0 Compiled dependence with actual values: According to the dependence 2, a ranged curve of the influencedegree of the mixer pressure factors Н, vacuum in the suction pipe of the pump В2and vacuum in the mixer body В1 (picture 10)is built.  Figure 10 shows that the maximum effect on the value of potential energy in the suction pipeline of the mixer S exerts mixer pressure H-66.37 %,minimum -vacuum in the mixer body В1=7,30 %. In addition, to compare the experimental and calculated data for the dependence 2, the values of the criterion S were calculated and are shown in Figure 11, from which it can be seen that the highest potential energy value of 15.6 m was obtained at the maximum vacuum values in the mixer body (-8 mand 18 m) and medium vacuum in a centrifugal pump (-3 m).  Table 3. The planning matrix and the results of the second group of experiments are shown in Table 4.
the dependence is written in natural values (4), according to which the maximum and minimum values of the criterion (total energy) S2 in the suction pipe of the mixer (table 5). ' The analysis of the second group experiments'results on the calculated values of the potential energy values according to the dependence 4 is shown in Table 5 and in Figure 11.
The calculated values of the criterion S in the mixer suction pipe are calculated according to the dependence 4.  experimental data (Tables 2.4) and calculated according to the obtained equations (2,4), fluctuates within 10-20 m, which makes it possible to calculate the hydraulic parameters of the fertilizer supply system to the suction pipelines of pumping stations, regardless of the hydromechanical equipmentcharacteristics.

Conclusion
As a result of the experimental studies, mathematical dependences were obtained for the development of the foundations for calculating the possibility of determining the place of the fertilizer mixer installation on the pumping station territory.