SU1183162A1 - Powder dispenser - Google Patents

Abstract

1. DISPERSANT, containing a vertical case, along the axis of which a drive shaft is placed with profiled radial blades and fixed radial profiled knives located between them, fixed to the wall of the case, and a shifting device placed in the lower part of the case, similar to the fact that In order to increase the degree of dispersion, the mixing device is made in the form of a diagonal pump, including an impeller placed on the drive shaft and a casing whose inlet is matched with the wall of the housing and connected to the outlet pipe through a pipeline, I 2. A disperser according to claim 1, characterized in that the blades (L of the pump impeller have a super-wedge profile with a wedge shape with a sharp leading edge.

Description

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9) About

11183

The invention relates to the dispersion, gyroscopic and homogenization of food semi-finished products, in particular for the production of homogeneous pulps from fruit, year and grapes in the food industry, as well as for the preparation of finely dispersed suspensions, emulsions in other areas of industry, for example, chemical and petrochemical .

The purpose of the invention-and-the increase in the degree of dispersion with a decrease in energy consumption.

FIG. 1- shows a dispersant, a longitudinal section; FIG. 2 is a section A-A in FIG. one; in fig. 3 - section 5-B in FIG. one; in fig. 4 is a section B-B in FIG. 2; in fig. 5 is a cross section of G-Gnafig. 3; in fig. 6-blade impeller, cross section along profile chord .20

The disperser comprises a vertical body 1 consisting of an upper cylindrical part 2 serving as a macro-dispersing chamber, with an inlet nozzle 3, a middle part extended in the form of a condenser 4, and a lower part in which a mixing device is placed, which is filled in the form of a diagonal pump 5, which includes a knuckle 7 placed on the drive shaft 6 30 and a casing 8 whose inlet 9 is connected to the wall of the housing and connected to the outlet 10 by means of a pipe 11 on which the flow regulator 12 35 is installed. At the same time, the blades 13 of the impeller 7 have a supercavitating profile of a wedge-shaped form with a sharp leading edge 14. It is the impeller of the diagonal pump 40 that has the blades of the supercavitations profile to create cavitation modes at a sufficiently high pressure.

A sufficiently high pressure is required in order to enhance the degree of cavitation dispersion. As the cavitation bubbles collapse in the zone of increased pressure, behind the blades 13 of the supercavitating profile, the speed of cumulative streams is much higher than at lower pressure, and the intensity of cavitational dispersion is Auger Bbmie.55

In addition, high pressure is necessary to pump the dispersible mass through the circulation pipe.

recycling pipe 11 if an even greater degree of dispersion is needed, i.e. to control the degree of dispersion and to supply a dispersible mass for further processing. The impeller 7 is installed in the narrow part of the confuser 4 (representing the inlet of the pump 5) in order to facilitate the occurrence of cavitation modes on its blades, since in the narrow part of the confuser the speed of the mixture is maximum and the pressure is minimal, therefore the formation of cavities occurs with minimum energy costs.

To reduce the resistance (energy consumption) and prevent cavitation of the walls of the confuser 4, it is made up of a length of 1-1.5 times the diameter of its wide part, i.e. cylindrical part 2 of case-1, with a generatrix as a function of sine. Such a length and profile of the confuser ensure, as shown by comparative tests of confusors of various shapes (Bitoshevsky, Butsa, Qing), its minimum resistance and minimum discharge peak at the point of maximum curvature in the narrow part, preventing its walls from cavitating. Therefore, the length of the inlet of the centrifugal pump 5, made in the form of a confuser 4, determines the most advantageous position of the impeller 7 at a distance of 1-1.5 times the diameter of the cylindrical part of the housing 1 from the profiled knives 15, the profile of the confuser forming a sinus function, prevents cavitation of the walls and ensures its minimal resistance.

In the cylindrical part 2 of the housing 1, profiled radial blades 16 with sharp edges 17 are fixed to the drive shaft .6, and fixed radial profiled knives 15 with sharp edges 18 located between the radial blades 16 are fixed to the housing wall.

To adjust the gaps between the blades 16 and the blades 15, eccentric mechanisms 19 are installed in the wall of the housing 1, allowing the gaps between the blades to vary from the maximum in the upper pair of working elements to the minimum in the lower pair. 3 In front of the blades 16 and the blades 15, movable knives 20 are pre-crushed at the entrance to the cylindrical part 2 of the housing 1. Knives 20 are installed when using a dispersant to grind coarse fractions of a dispersible product, such as whole blocks. Before the blades 20, on the supports 21 of the upper bearing assembly 22 are axially displaced, guide plates 23 are rotated to adjust the clearance. Shaft 6 is rotated by an electric motor 24 mounted on frame 25. In order to provide different modes of operation, the dispersant is provided with an outlet nozzle 26 with a valve 27. The dispersant operates as follows. Dispersible product through the inlet pipe 3 enters the cylindrical part 2 of the case 1 of the dispersant. When the shaft 6 rotates, the knives 20, together with the guide plates 2, preliminarily grind the product of dimensions 2–8 mm, then the movable blades 16 and the stationary knives 15 crush the product to a homogeneous liquid mass. Moreover, this grinding is purely mechanical, based on multiple interactions of the blades with the particles of the product and the kinematic collision of the particles of the product with each other. There is a rotary pulsation grinding of the product. However, the destruction of biological cells of the product does not occur in this case, since reducing the gap between the lower pair of working sjieMeHTOB to sizes smaller than 0.2 mm is technically very difficult, and in devices of high productivity (dimensions) it is almost impossible. In this case, the specific energy consumption for dispersion increases very sharply. Therefore, the minimum gap between the lower pair remains rather large, not less than 0.5-1 mm, and the gap of the leading pairs is correspondingly large. The resulting homogeneous liquid mass with a particle size of 0.2-0.7 mm (200-700 microns) is accelerated into a confuser. up to the speed of 5-10 m / s. When the impeller 7 rotates on its blades 13, cavitation cavities are formed along 624 the entire flow area of the annular channel, which are closed in the fluid flow behind the blade 13 of the supercavitating profile due to the increase in pressure due to the centrifugal action of the blades. When caverns are closed, the floor of the cavitation microbubbles is formed, which collapse in the same zone. At. Microbubble collapses form cumulative micro jets of 5–25 µm in size with velocities of the order of 1000 m / s. When a microjet collides with a dispersible particle of gas, local shock pressures occur on the order of 10,000 atm and the particles are destroyed. The cell structures and the cell walls themselves are destroyed. . This contributes to an increase in the output of cell sap, for example, when obtaining block or grape pulps from juices, and also has a grinding, mixing, dissolving microkinetic effect on the treated substances. Then, the dispersible mass under the pressure of 3-5 atm created by the impeller enters the outlet 10 of the pump 5 and then (if necessary even more dispersing to particle sizes of 0.55 µm) enters the wide part of the confuser A. The regulator 12 the flow rate allows one to control the degree of dispersion within fairly wide limits from particle size of 150-500 µm to 0.5-5 µm by increasing or decreasing the circulation ratio. The device can operate both in continuous mode with open valve 27 installed in the outlet nozzle 26, with a degree of recirculation (dispersion) set using the regulator 12, and in a periodic mode with the valve closed 27. Cavitation resistance of blades of a supercavitating profile wedge-shaped with a sharp front edge is 5-10 times lower than resist. Stinging trapezoidal blades. In addition, the impeller is diagonal. The pump has a pumping effect and creates a pressure of 3-5 atm at the pump outlet, which allows not only to recirculate the dispersed mass, but also to apply it to further technological treatment without additional pumps.

The zone of cavitation bubbles cavities in the proposed apparatus is limited to the annular channel of the pump and is strictly limited due to the increase in pressure behind the impeller blades,

which protects the walls of the apparatus from cavitation destruction. In addition, at a higher pressure, the intensity of the cavitation – kzt positive effect is higher, increasing the pressure from 1 to 5 atm increases the intensity of the effect by 20–25%.

FIG. g

1183162

5-6

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Claims (2)

1. dispersant comprising a vertical body axis of which is placed a drive shaft with radial blades shaped races and laid between the fixed profiled radial blades fixed on the housing wall, and a stirring device arranged in the lower housing portion of t ^e l ichayuschiysya in that, in order to increase the degree of dispersion, the mixing device is made in the form of a diagonal pump, including an impeller and a casing located on the drive shaft, the inlet of which is paired with the wall of the housing and is connected to the outlet pipe by means of a pipeline. 2. Dispersant pop. 1, on t and - § characterized in that the impeller blades of the pump have superkayyutikiy profile wedge-shaped with a sharp leading edge. 00 oo X