RU2158183C1 - Installation for electrostatic treatment of binding material - Google Patents

Abstract

FIELD: processes realized with use of electron and ion beams for hanging material properties and controlling product quality. SUBSTANCE: installation includes arranged in housing: zones for atomizing and charging particles of binding material, electrodes connected with power source, inlet and outlet ducts. Three concentrically arranged cylindrical drums are mounted in housing. Intermediate metallic drum is connected with voltage source. Outer and inner drums are made of dielectric material. Intermediate and outer drums are mounted with possibility of rotation. Ring shaped electrodes are not insulated and they are arranged along the whole surface of outer drum. At outlet of charging zone in housing there are electrically conductive members for cleaning and grounding electrodes. Through-type mutually communicating cavities are provided in walls of inner drum along its whole length. Voltage source is placed inside inner drum. EFFECT: enhanced efficiency of electrostatic treatment of binding material, increased strength of products with such binding material. 4 cl, 2 dwg

Description

 The invention relates to the field of engineering and technology using electronic and ion beams for directionally changing the properties of materials, controlling product quality.

 One of the promising areas of the use of electric energy in technological processes is electron-ion technology (EIT), which is based on the effect of strong electric fields on particles of dispersed bulk material. EIT has a number of obvious advantages over traditional types of processing (mechanical, chemical, and others), in particular, the direct effect of the electric field on the raw materials without intermediate energy transformation, the locality and selectivity of the effect while maintaining the purity of the starting material, the absence of mechanical effects on the material during processing, and the ability to control processes and the fundamental possibility of exposure to all types of materials. All this points to the promising use of EIT equipment in workshops and laboratories of modern production facilities.

 A known installation of electrostatic dedusting / 1 /, equipped with a channel for the input of contaminated gas to be cleaned, a system of corona electrodes and collector electrodes connected to a high voltage source, a device for shaking off dust particles deposited on the collector electrodes, channels for removing dust particles and exit purified gas.

 However, in such an installation, charged dust particles, settling on the collector electrode, lose their charge and are sent to the output channel in the form of agglomerates from flakes firmly adhered to each other.

 A device for a quiet discharge that implements the method of electrostatic treatment of cement / 2 /. The device is made in the form of a horizontal prismatic pipeline and consists of a chamber for spraying cement and a chamber for charging cement particles interconnected by a spring-loaded corrugated tube. A DC and AC power source is connected to the charging chamber. An electromagnet is connected to the spray chamber in order to realize oscillatory movements by the camera. The cement grain charging chamber is equipped with two alternating groups of electrodes arranged in the form of compact batteries and connected respectively with alternation to a constant high voltage source and an alternating voltage source. The electrodes of both groups are made in the form of rods with ceramic insulation. Cement powder in the spraying chamber turns into a cement-air mixture, and in the charging chamber it undergoes monopolar ionization and additional shaking with an alternating electric field, which results in an increase in the strength of cement-concrete products.

 However, such a device has a low bandwidth and, therefore, low productivity, which is associated with the inability to increase the distance between the electrodes without simultaneously weakening the electric field, and hence reducing the efficiency of the device. In addition, the electromechanical shaking provided in the device does not completely exclude the shielding of the electrodes by cement particles, which also reduces the efficiency of the device. The temperature, the increase of which leads to a sharp decrease in the concentration of ions in the charging chamber, has a negative effect on the stability of the effect of electrostatic treatment.

 The basis of the invention is the creation of such a device design, which would provide an increase in the efficiency of electrostatic treatment of a binder, resulting in an increase in the strength of products based on a processed binder.

 The problem is solved in that the installation for electrostatic processing of binder material, comprising spraying and charging zones of binder particles located in the housing, electrodes connected to a voltage source, input and output channels, according to the invention, is equipped with three concentric cylindrical drums installed inside the housing, one of which, the middle one, is made of metal and connected to a voltage source, and the inner and outer are made of a dielectric, the middle and outer bar They were installed with the possibility of rotation, ring-shaped electrodes were not isolated and placed over the entire surface of the outer drum; in addition, electrically conductive elements for cleaning and grounding the electrodes were installed in the housing at the exit from the charging zone, while through the walls of the inner drum were made through cavity, and the voltage source is installed inside this drum.

 To create a uniform electric field, the electrodes on the surface of the outer drum are arranged uniformly with a step equal to 3H / 2, where H is the height of the ring electrode.

 To protect the electrodes from mechanical damage, the elements for cleaning and grounding the ring electrodes are made soft.

 For effective cooling of the electrodes, the through cavities are made communicating, for example, by means of holes.

 The location inside the installation case of three cylindrical drums in the above way allows us to ensure that all particles of the binder to be treated are exposed to an electric field created between the middle metal drum and the ring electrodes by a high voltage source, which results in an increase in the efficiency of electrostatic processing of the binder material.

 The use of non-insulated ring electrodes allows in the space between the electrodes to obtain a zone of monopolar charging of the binder particles in order to increase the dispersion of the binder material, which results in acceleration and increase the degree of hydration of the binder during mixing with water and, as a result, increased strength of products based on the treated binder.

 The implementation of through cavities in the walls of the inner drum allows the electrodes to be cooled by passing coolant through, for example, cold water, in order to increase the number of ions in the interelectrode gap, which results in an increase in the efficiency of the installation.

 The use of ring-shaped electrodes allows cleaning the electrodes without damaging the latter, while cleaning the electrodes of binder particles adhering to them prevents the screening (weakening) of the electric field.

 A known installation for the extraction of substances and particles from suspensions and solutions / 3 /, which uses the principle of the edge effect of the electrodes. However, the operation of such a device designed for processing liquid materials will be ineffective and unacceptable for processing loose binder, since both electrodes and the material to be processed are structurally separated by a dielectric layer that weakens the electric field.

 The invention is illustrated by drawings, where in FIG. 1 shows the construction of the installation in a section perpendicular to the axis of rotation of the drum; FIG. 2 - installation design in section along the axis of rotation of the drums.

 The installation is made in the form of a horizontal prismatic pipeline placed above the mixer, and contains cylindrical drums installed concentrically in one another in the housing 1: an inner drum 2 of a dielectric, in the walls of which through holes 3 communicating through the openings 3 are made through holes 3 for passing refrigerant, the middle metal drum 5 and the outer dielectric drum 6. The middle and outer drums are interconnected with the possibility of simultaneous rotation and with a drive for rotation I drum 7. Inside the drum 2 is stationary voltage source 8, which is the same as the actuator 7 is connected to the network. On the entire surface of the drum 6, ring electrodes 9 are located perpendicular to the axis of rotation thereof. Inside the housing 1, electrically conductive elements are installed for cleaning the electrodes 10. In the upper part of the housing 1 there is an input channel 11 for supplying a binder, and in the lower part an output channel 12 for output processed cementitious material.

 Installation works as follows. The source material (binder) through the inlet channel 11 enters the spray zone A. From zone A, the binder particles move to the surface of the drum 6 under the influence of gravitational forces. Before the binder particles reach the surface of the drum 6, they enter the charging zone B created by the drum 5, which is connected to one pole of the high voltage source 8, and ring electrodes 9 grounded through the conductive elements 10. The electric field in the installation zone B at the surface of the outer drum 6 is created due to edge effects to ring electrodes 9, while there is a field gradient with increasing intensity at the surface of the drum 6. Since the drum 5, which acts as a high voltage electrode, is isolated, and the ring electrodes 9 are not isolated, a large number of ions are formed in the space between the electrodes as a result of air ionization one sign. These ions create a unipolar charge for the binder particles, passing through which the previously neutral binder particles polarized by the electric field acquire an excess charge by trapping the ions of zone B, that is, they are charged. For large particles, such as binder powder particles, the main role during charging belongs to the process of directed movement of ions to a binder particle under the influence of electric field forces. Then, the charged binder dispersed powder reaches the surface of the drum 6, during rotation of which the treated binder particles are removed from its surface either by gravitational forces or mechanically using elements 10. The processed binder is removed from the device through the outlet channel 12.

 This installation for the electrostatic processing of binders can be used in the manufacture of any products based on binders (gypsum, lime, cement), for example, for housing and industrial construction, in the foundry industry in order to increase the strength of molds for casting jewelry, compressor wheels etc.

SOURCES OF INFORMATION
1. F. Tanesescu, R. Kramaryuk. Electrostatics in technology. - M.: Energy, 1980, p. 2018.

 2. RF patent N 2073362, C 04 B 40/00, decl. 6.10.94, publ. 02/10/97. The method of electrostatic processing of cement.

 3. RF patent N 2098193, B 03 C 7/06, application. 07/26/95, publ. 12/10/97. Installation for the extraction of substances and particles from suspensions and solutions.

Claims (4)

 1. Installation for electrostatic processing of binder material, comprising spraying and charging zones of binder particles located in the housing, electrodes connected to a voltage source, input and output channels, characterized in that it is equipped with three concentric cylindrical drums installed inside the housing, one of which , middle, made of metal and connected to a voltage source, and the inner and outer are made of dielectric, the middle and outer drums are installed with the possibility rotations, ring-shaped electrodes are not isolated and placed on the entire surface of the outer drum, in addition, at the outlet of the charging zone, electrically conductive elements are installed in the housing for cleaning and grounding the ring electrodes, while through cavities are made in the walls of the inner drum along its entire length, and A voltage source is installed inside this drum.  2. Installation according to claim 1, characterized in that the electrodes on the surface of the outer drum are evenly spaced with a step equal to 3H / 2, where H is the height of the ring electrode.  3. Installation according to any one of paragraphs.1, 2, characterized in that the elements for cleaning and grounding the ring electrodes are made soft.  4. Installation according to any one of claims 1 to 3, characterized in that the through cavities of the inner drum are made communicating.

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