SU1813544A1 - Vertical planetary mixer - Google Patents

Description

The invention relates to the field of chemical industry, in particular to the designs of vertical planetary mixers for highly viscous (over 1000 Pa-s) explosive and fire hazardous products.

Known vertical mixer [l]. The mixer is equipped with two curved paddle mixers (low-speed and high-speed), moving along the cycloid. The gear ratio of the stirrers is 1: 2. Each of the mixers has two spiral blades formed by the attacking concave surface and the rear convex surface, connected by an external peak. The high-speed mixer, in contrast to the slow-moving one, is equipped with a central window, which allows the mixing of highly viscous compounds to provide an additional mass flow and to exclude the influence of the plow effect when voids remain behind the mixer. Component loading, including chys _; le loose, carried out through the pipe at the top of the mixer. > A disadvantage of the known designs is that the blades are made in the form of spiral curved rectangles, while the upper edges have a slight slope and a significant area, as a result of which

1813544 A1 '

when highly viscous materials are mixed, powdered components precipitate on them during loading. This leads to the formation of stagnant zones and g can distort the percentage of components in the composition. In addition, studies have shown in the processing of highly viscous materials containing components with increased adhesion to metal, the formation of stagnant zones on the attacking concave surface of the blades of high-speed mixers is noted. In these zones, after the mixing process, the presence of a mass not corresponding to the given formulation was noted.

The aim of the invention is to improve the quality of mixing by eliminating stagnant zones. 20

Figure 1 shows the design of the upper edges of the mixer; in FIG. 2 shows a section along the upper edge of the mixer; FIG. 3 shows a section along a plane perpendicular to the axes of the mixers (the mixer 1 shown in FIGS. 1 and 3 is high-speed and the mixer 2 is slow-moving); figure 4 shows the interaction of self-cleaning mixers in the process of operation of the mixer. thirty

The proposed design of the upper part of the mixers allows to avoid settling of components, especially powder ones, when loading the components. The value of the angle of inclination o6 = 40 ... 35

50 ° of the upper edge 3 is assigned in such a way as to ensure the draining of the components and at the same time to preserve the active zone of the mixers as much as possible. For a similar purpose, bevel 4 is made with an inclination angle β '= 40 ... 50 ° (in the section Λ-A).

The profile of the blade in the cross section of a high-speed peripheral mixer equipped with a window is formed by the rear surface 45 and the attacking surface 6.

Used in the prototype cross-section l'opasta high-speed mixer (shown in dotted line in Fig. 3) led to the appearance of stagnant zones on the concave attacking surface. The implementation of this surface flat and at a certain angle y = 15 ... 25 allows you to form an incident mass flow in such a way that it is a constant mass exchange. At the same time, the flow, passing along the surface of the danger, enters the window of the mixer, without forming stagnant zones. An important role is played by the angle of inclination of the surface (in each section perpendicular to the axis of the mixer) to the line connecting the opposite; the most distant one from the other, the cross-section points a and a \ So, at an angle of less than 15 °, the resistance of the mixed material to rotation of the mixer sharply increases, which is associated with an increase in drive power. This reduces the intensity of the movement of the material from the wall to the inner part of the volume of the mixer. With an increase in the angle of more than 25 °, the cross section of the feather of the blade decreases and, therefore, the mechanical strength of the mixer.

The profile of the blade of a low-speed mixer is formed from the conditions for ensuring a constant gap between the mixers. In FIG. 4 shows one revolution of a high-speed mixer when it interacts with the blade b of a low-speed mixer. After this, the mesh-1 interaction process is repeated cyclically.

The conducted experimental work showed the effectiveness of the proposed con- _; mixer structure. When mixing a highly viscous polymer composition (1000 Pa s) with a finely divided powdery filler (with a specific surface of 1500 ± 500 cm ² / g), there was no powder sticking to the surfaces of the working bodies and lifting of the mixed material to the nodes, seals in the upper part of the mixers.

Claims (1)

Claim' Vertical planetary mixer, comprising a housing, low-speed and high-speed paddle screw self-cleaning paddle mixers with upper edges and a convex rear surface, and a window made in a high-speed mixer, a concave attacking surface of the low-speed mixer and with a gear ratio of rotation 1: 2, characterized in the fact that, in order to improve the quality of the product by eliminating stagnant zones, the upper edges of the agitator blades are located with a negative slope at an angle of 40-50 ° C and have bevels made under angle. 40-50 ° to the surface of the blade, at. this attacking surface of the blade of the high-speed mixer is made flat with an angle of inclination in each section, 5 ‘1813544 6 perpendicular to the axis of the stirrer to the line, [from another cross-section point equal to 15 connecting the most distant one 25 °.