The dissertation is aimed at solving an important scientific and technical problem - increasing the efficiency of the process of obtaining innovative granular organo-mineral fertilizers necessary for the implementation of the principles of rational land use.
The aim of this work is to scientifically substantiate the use of a bowl rotary disperator to increase the efficiency of the granulation process of multicomponent highly concentrated liquid systems in a fluidized bed.
The principles of using a bowl rotary disperator with a perforated surface for introducing a heterogeneous liquid phase into the fluidized bed have been scientifically substantiated, which has significantly increased the size of the total dispersion zone due to liquid spraying through the side surface of the disperator and intensive movement of moistened granules.
For the first time, the hydrodynamic modes of fluid movement in the bowl of a rotary disperator were determined experimentally, in which the average droplet size in the distribution zone dcr ≤ 250 μm is controlled.
For the first time it was experimentally proved that the use of a bowl rotary disperator with a perforated side surface allowed to increase the dispersion zone at least 5 times compared to the disk disperser, which significantly increased the stability of the kinetics of the layered granulation mechanism.
In this work, the dependences for determining the mode of operation of the rotary disperator, which provides an increase in the spray zone at an average droplet size of less than 250 μm, are obtained experimentally.
Technological parameters of the process of obtaining granular humic-organo-mineral fertilizers with given properties in dehydration of multicomponent liquid systems containing up to 60% (wt.) Dry matter (bone meal, ammonium sulfate, humate and potassium chloride) are determined.
It is theoretically substantiated and experimentally proved that the use of a bowl rotary disperator with a perforated side surface allows to increase at least 6 times the size of the spray zone compared to the disk disperser and to create active circulation of granules through the disperator bowl with a frequency of 1.7 ÷ 2.0 Hz. effective distribution of moistened granules among dry and significantly reduces the risk of agglomeration
To evaluate the operation of the rotary disperator, which provides the average droplet size in the spray zone dcr ≤ 250 μm, it is proposed to use the film formation factor in the disperser bowl as the product of the film Reynolds number on the centrifugal Freud number Hg = Reпл(1)·Frmin parameter Hg = (3,8 ÷ 4,0)·104.
It is experimentally confirmed that the use of a rotary dispersant with values of
Hg = (3,0 ÷ 3,5)·104 in the dehydration of 40% (wt.) Working solutions provides a layered mechanism of granulation in the production of granular humic-nitrogen fertilizers with a granulation coefficient Ψ ≥ 90 %, the specific load of the surface of the layer on the moisture af = 0,43 kg / (m2 · h) and productivity on the granular product of 1 m2, which is 1,4 times higher than this figure for the process using a disk dispersant.
Achieving high quality distribution of the liquid phase in the fluidized bed is confirmed by a mathematical model of the granulation process, which with an error of 5.7% describes the change in temperature along the height of the layer using jet-pulsation fluidization for three hydrodynamic zones in the granulator chamber
It is experimentally proved that the use of rotary dispersant type 1 in dehydration of multicomponent heterogeneous liquid systems with a dry matter content of 60% consisting of ammonium sulfate - 27%, bone meal - 29% and humates - 1% allowed for the first time to obtain humic-organo-mineral fertilizers G: P: Ca: N: K: S = 1: 10: 19: 11: 2: 12,5 in the form of granules with a layered structure with an equivalent diameter of 2.5 ≤ de ≤ 4.0 mm, the granulation coefficient is Ψ ≥ 88%. The high efficiency of the process is confirmed by the increase in the specific load of the surface of the layer on moisture af = 0,51 kg / (m2 · h) in 2 times and in 3 times productivity on the granular product from 1 m2 of gas distribution device - 197 kg / (h · m2) in comparison with indicators for the process using a disk dispersant.
