PROVEMENT OF CONSTRUCTIVE PARAMETRES OF SPIRAL-SCREW DOSING UNIT WITH DOSE REGULATOR BY VARYING SPIRAL REVOLUTION TURNOVER NUMBER
For dosed delivery of combined fodder to animals in a range of 0.5 to 1.5 on farms massive dosing units are used, a spiral screw one is one of them (SSDU). An accuracy of delivery of a preset dose depends on frequency of rotating of screw spiral, which may vary in a time at varying strain and loading on a drive. For exclusion of this disadvantage it is suggested to conduct discrete dosing, setting spiral revolution number (a number of doses obtained at one turnover). At Perm State Agricultural Academy a laboratory installation has been created. Its drive permits a shaft of screw spiral to fix\ stop at one position independently of an amount of the revolutions performed by it. For determining parameters of SSDU a non-composition plan of second order of Box-Behnken was used. A dosing unit was investigated at spiral diameter of 49m 73, 97 mm, at spacing of 0.75d, 1d, 1.25d and clearance between spiral and cover of 2.5, 5, 7.5 mm. Equations of regression for working power, specific material feeding at one spiral revolution were obtained and so was got a coefficient of variation of some constructive parameters. The surfaces of response were built up with the help of these equations. Dry material delivery at one spiral revolution varied from 16.9 to 254.3 gram per revolution, consumed power was in the limits of 40-47 volt. Standard deviation of dosing crumbled shorts comprised 1 - 3.5 % and 1.2 - 5.5 % for granules of 5 mm. There were established the optimum parameters for qualitative performance of SSDU: spiral diameter - 49 mm, spiral spacing - 1d and clearance - 5 mm. At these parameters relative deviation of dosing does not exceed 1.7% that is 2 times lower in comparison with dosing at continuous performing of SSDU.