SU1735022A1 - Mixer-activator - Google Patents

Description

The invention relates to a mixing technique and can be used in construction, in installations of continuous action for the preparation of a cement-sand mixture.

Mixers for bulk materials are known, comprising a cylindrical body with loading and unloading ports, two shafts rotating opposite each other with paddles for mixing.

A disadvantage of the known mixers is the absence of an effective effect on the particles of the components, leading to their grinding, in connection with which there is no increase in the dispersion of the cement, and consequently, there is no residual properties of the cement.

In addition, the vertical location of the mixer leads to the concentration in the lower part of the main mass of the mixture, which impairs the process of mixing.

The closest to the claimed technical entity is a mixer-activator containing a cylindrical body with loading and unloading openings, on the inner surface of which parallel to its axis there are attached reflective elements representing a comb consisting of fingers made with longitudinal grooves , having in cross-section arcuate shape and drive shaft.

The disadvantage of this device is the absence of an effective effect on the particles of the components, i.e. mass crushing is not observed, which provides for an increased dispersion of cement, on which the binding properties of the mixture depend, which, when mixed with water, form a plastic mass that hardens into a solid stone-like body.

Thus, the greater the dispersion of cement, the greater the adhesion properties of the mixture, and hence the strength of the products, of which this mixture is an integral part.

The increased strength of the products due to the more viscous mixture makes it possible to reduce the amount of cement.

The aim of the invention is to improve the quality of activation of the mixer-activator.

This goal is achieved by the fact that in the activator mixer, which contains a horizontal cylindrical body with loading and unloading openings, on the inner surface of which parallel to its axis are reflective elements, and a drive vane shaft, each reflective element is made in the form of a plate of rectangular cross section, moreover, the distance between the plates is determined by the formula

I R sin arccos (1 - -),

TO

where I is the distance between the plates;

R is the radius of the inner surface of the housing;

h is the height of the plate section.

The implementation of reflectors in the form of plates of rectangular cross section with a specified specific distance between the plates provides intensive grinding of cement grains, i.e. increases its dispersion. In addition, these plates contribute to better mixing of the components.

These advantages of the plates are determined by a certain path of movement of the particles of the components inside the mixer.

In the process, the plates pick up the cement-sand mixture and attach

her rotational motion, the particles of the mixture under the action of centrifugal forces are shifted to the periphery, as if slipping along the blades. The separation of the mixture occurs mainly from the ends of the blades.

The mixture to the plane of the blades in steady motion is pressed under the action of the inhibited part of the mixture, which is formed from collision with particles moving from the interscapular region.

spaces, and with particles reflected from-attached to the inner surface of the body plates. As the particles move to the periphery, their linear velocity increases, since with a constant angular velocity, the radius of their rotation increases. The maximum speed and maximum energy of the particle acquire at the time of descent from the end of the blade. The linear velocity of the particles is tangential to the curved path of the end of the blades.

If these particles are given a direct elastic impact, then the probability of their destruction will be maximum. Cement particles like

less durable, subjected to intensive crushing, which is confirmed by the experiments.

Based on the above, the distance between the plates is chosen so that

The bulk of the particles with the maximum energy were struck not oblique, but close to direct.

These requirements are met, provided that the direction of the velocity vector of particles / l at the time the blade passes over

The i-th bar will pass through the point of contact (i + 1) of the plate and the body. At the same time, the bulk of the particles with high energy will not strike the wall of the body, but the plate. Graphically, this is shown in the diagram (Fig. 1).

Triangles OAB and DIA rectangular by construction, whence OC-CA R-h

OBR

Cos a

a arccos (1 -), k

AB R sin a -sin arccos (1 -),

R

CB I Ac 2 + AB 2.

Since it can be assumed that AB is approximately equal to CB due to the insignificant height of the plate relative to the radius of the cylinder body, then AB I, from here

h

I R sin arccos (1 - -U, K

where R is the radius of the inner surface of the housing;

h is the height of the plate section;

I is the distance between the plates.

Figure 1 shows the mixer-activator, a longitudinal section; figure 2 - section aa in figure 1; Fig. 3 is a diagram of a graphic image of a velocity vector.

The cement-sand mix-activator is a cylindrical case 1 equipped with a hopper 2 for loading the components of the mixture with an open damper 3 and an discharge opening A with a damper 5. Inside the housing 1 forming the mixing chamber there is a shaft 6 equipped with paddles 7 and internal 8 mixing, as well as blades 9 for protecting the bearing assembly from the penetration of abrasive particles. The shaft 6 is rotated from the engine 10 by means of a belt drive 11. On the inner surface of the cylindrical body, parallel to its axis are reflective elements in the form of plates 12 of a rectangular cross section h 20 mm with a pitch I 150 mm and a radius of the inner surface of the body R 400 mm .

Mixer-activator works as follows.

A bulk filler (cement and sand) is fed through the hopper 2. Mixing the mixture is carried out due to the action of centrifugal forces arising from the rotation of the high-speed shaft 6, and due to the location of the working surfaces of the blades 7 and 8 at certain angles of inclination to the axis of the shaft. Due to the action of centrifugal forces and the location of the plates 12 with a certain distance in the housing 1, intensive mixing and grinding of cement occurs. The blades 7 pick up the mixture flow and direct it to the zone of action of the blades 8, as a result of which there is an intensive mixing of the cement-sand mixture practically throughout the whole volume of the mixing chamber. The thoroughly mixed mixture is moved along the axis of the shaft 6, directed towards the discharge opening 4,

Compared with the known devices, the claimed device provides cement savings of 30-35% with the design strength of reinforced concrete products, and with equal quantities of cement, it increases the strength of products by 70-80% and increases the frost resistance of products by 2 times.

/

Claims (1)

Invention Formula An activator mixer containing a horizontal cylindrical body with loading and unloading openings on the inner surface of which parallel to its axis are reflective elements and a drive vane shaft, characterized in that, in order to improve the quality of activation, each reflective element is designed as a plate mongular cross section, and the distance between the plates is determined by the formula I R sin arccos (1 - Ј-), K where I is the distance between the plates; R is the radius of the inner surface of the housing; h is the height of the plate section. FIG. 2