SU141142A1 - Continuous Dosing Mixer - Google Patents

Description

The design of the mixers, having parallelly arranged with respect to each other screws, placed in a common housing, are known. Such machines are used in blending and kneading various thermoplastic polymeric materials. Designs of mixers and electric dozatori are also known, having two pairs of screws arranged opposite to each other and enclosed in a common building. However, these constructions used for technical purposes do not have elements for controlling the basic parameters (pressure and productivity) and, as a rule, they are intended for well-defined processes and substances with certain properties.

The known constructions do not allow changing the conditions of treating substances according to a predetermined program, complicate the transition to treating substances with different properties, and in many processes cannot provide optimal conditions for the technological process.

The proposed continuous batch mixer differs from the known ones in that a pair of screws in it is equipped with an individual electric drive providing independent control of the rotational speed of each pair of screws. Such a design allows a quick readjustment of the metering blender to work, which corresponds to the optimum technological regime when processing various bulk or semi-solid materials.

The proposed metering mixer, the circuit diagram of which is shown in the drawing, consists of two twin screws / and 2, rotating in the housing 5 with the loading hopper 4 and the discharge pipe 5. The housing in cross section A-A has a geometric shape

No. 141142- 2 two intersecting circles. Each pair of worms / and 2 is set so that the turns of one worm go into the hollows between the other, parallel, and parallel worm. In each pair, the worms rotate in the same direction. A Caleda pair of screws is driven by an individual drive consisting of a gearbox and a DC motor or hydraulic motor.

In order to maintain a constant number of revolutions of a pair of W /, the electric motor for it is adopted with a rigid characteristic of the number of revolutions, for example, with a compound winding.

For a pair of screws 2, on the contrary, the electric motor is selected with a steep characteristic of the rotational speed, depending on the load, for example of the series type. As practice has shown, parallel-arranged screws, in the presence of material back-up at the outlet, have 100% filling of the turns of the material being processed and can develop a pressure that depends only on the strength of the screw, drive power and material properties. With sufficiently thick materials, the pressure developed by the twin worms can reach several hundred atmospheres.

Dosing mixer works as follows.

The substance to be processed from the hopper 4 is fed with a worm gear pair 2 to worms 1, which can be given a smaller number of turns than worms 2, with the same other parameters. Worm-intake / material is discharged through nipple 5.

The adjustment of the revolutions is carried out by introducing resistance into the winding of the DC motors or regulating the pressure when driven by the hydraulic motor. With a smaller number of revolutions, a worm pair /, as compared with a worm 2, the material to be processed is compressed in order to a greater degree, the more the difference between the revolutions of the worm pairs.

The pressure in the pressing zone is achieved by using a worm gear pair 2 to drive a serial motor, which, with an excess supply of material and an increase in pressure above the established rate, reduces the number of revolutions, and if there is a shortage of material, it increases the number of revolutions. By this, the system is regulated relative to a predetermined pressure in the zone of compaction of the material.

The indicated property of the mixer batch can be used for various purposes, for example:

1. For continuous dosing of bulk materials. At the same time, before volumetric dosing with a worm gear pair 1 having a stable rotational speed, the material is compressed with a screw 2 to a strictly defined bulk weight. This principle is used to create continuous mass dosing dispensers of the type with a dosing accuracy of 0.5-2%.

2. When semi-solid masses are displaced, for example, granular substances, with a liquid, due to the use of a blender dispenser with two paired shnekami, it is possible to choose the optimal mode of backwater, and hence the displacement. This dispenser-mixer allows a continuous displacement process for small batches of materials, since its re-adjustment is very simple (moving the sliders of the rheostats).

3. The mixer-blender allows for the extraction of solids from the liquid component, under a strictly defined pressure, regardless of the amount of material supplied.

4. The mixer blender allows filtration of thick slurries at a strictly defined pressure. During the processes of pressing and filtering, the housing of the dispenser-mixer (see the second variant in the drawing) is made of separately placed plates (pallets) with gaps from 0.1 to 0.3 mm. Application areas of the mixer blender:

a) continuous dosing of bulk substances with a high degree of accuracy;

b) squeezing liquid components from solids (anthracene oil from naphthalene, liquids from pyroxylin and colloxylin, as well as from alkaline cellulose and for other processes);

c) mixing the components, followed by spinning.

Subject invention

A continuous batcher-mixer, consisting of a bed, a loading hopper, two pairs of opposite worm screws enclosed in a common housing, rotated by means of an electric drive, a worm speed control and speed control system, characterized in that quick changeover of the mixer-dispenser corresponding to the optimum technological mode when processing various bulk or semi-solid materials, each pair of screws is equipped with an individual electric drive, both Squeezing independent adjustment of its rotational speed.

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Option I