SU524780A1 - A continuous device for electrically heating ceramic and similar mixtures - Google Patents

Description

The last of the above devices is closest to the described invention.

The purpose of the invention is to provide uniform, zone-controlled heating of the mixture.

This is achieved by the fact that in the proposed device the conductive electrodes are made annular, mounted coaxially to the screws, and flat, fixed along a helical line. All electrodes are autonomously connected to a power source through a switching unit.

Electrocontact heating of ceramic and similar masses takes place at the expense of the electrically conductive properties of the material at the beginning and end of the process of stepwise or poson supplying an operating voltage of alternating current of industrial frequency to the electrodes. Volumetric heating of the mass is provided by fixing the flat electrode on the screw shaft between its blades through an insulator, which, in turn, creates the most favorable conditions for current distribution in the heated mass. The mass pushed by the screw closes the space between the electrodes and heats up as ohmic resistance, and the power lines are directed from the flat electrode from the cavities between the screw blades to the ring electrode or vice versa. A change in the direction of the current to provide equally symmetric heating of the near-electrode layers of the mixture is achieved by using a switching device with which all electrodes are autonomously connected.

FIG. 1 shows a longitudinal section of the described device; in fig. 2 shows section A-A in FIG. 1, cross section.

The device includes a mixer 1, equipped with a mixer for the preparation of the mixture and a mechanism for its forced advancement by the screw 2. A system of annular electrodes 3 of the first heating stage is mounted on the inner surface of the mixer housing. Along the screw line of the screw between its blades made of steel, a flat electrode 5 is fixed on the electrically insulating gasket 4.

To take air from the heated mass and continuously deliver it in the form of a profile of a given configuration (bar, cylinder, pipe, etc.), the device contains a vacuum chamber 6 with its mechanism of forced movement by the screw 7. In the cylinder 8 of the vacuum chamber, by analogy with the cone of the mixer is equipped with a system of annular electrodes of the second stage of heating, and along the helix of the auger between its blades made of steel, a flat electrode is also attached to the electrically insulating gasket.

To supply electricity to the flat electrodes 5, current collectors 9 and 10 are fixed on the shafts of the screws through the insulating rings.

The drawing does not show a device drive consisting of a gearbox, a speed variator and an electric motor. The temperature of heating of ceramic and similar mixtures is controlled by the device, supporting the automatic supply of the required amount of electrical power to each heating zone depending on the temperature difference at the entrance to the vacuum chamber and at the cylinder outlet.

A continuous device for electrically heating ceramic and similar mixtures is made stationary — all the mechanisms, components and control panel are placed on the frame.

The operation of the device is as follows.

The wet ceramic mass is loaded through the receiving device 11 and fed by the blades of the mixer of the mixer 1 to the screw 2, captured by its blades and mixed in the direction of the vacuum chamber 6. Locking the screw space between successively and electrically insulated ring electrodes 12 from the mixer 3 and a flat electrode 5 mounted on an electrically insulating gasket 4 on the auger, the mixture is heated under the influence of electric current to the warm-up temperature specified for each heating zone.

temperature The annular electrodes of the mixer and the flat electrode of the screw form the first heating stage. The propeller blades made of steel provide a sufficiently high performance of the device for the continuous heating of ceramic and similar mixtures up to 2.5 tons / hour.

At the entrance to the vacuum chamber 6, the mixture is cut by movable knives into tapes and falls on

bottom of the camera. In the vacuum chamber, the ribbons are vigorously agitated and subjected to vacuum. In addition, along with temperature equalization throughout the entire volume of the mixture, its plastic properties are improved. The ceramic mixture thus prepared is fed by a screw into the cylinder 8 of the vacuum chamber, in which it is subjected to final heating to a predetermined temperature. Cylinder Ring Electrodes, Flat Electrode

auger vacuum chamber form the second stage of heating. Depending on the parameters of the mixture at the entrance to the vacuum chamber and at the exit from it, the amount of electrical power supplied to each of the heating zones is automatically regulated. To provide equally symmetric heating of the moving ceramic mass, all electrodes are autonomously connected to the power source 13 through a switching device 14, the purpose of which is to ensure cyclic phase switching on the electrodes, i.e., for one separately considered electrode, three alternating current phases are alternately applied industrial frequency

A. B.C. and zero phase.

Claims (2)

1. A continuous device for electrically heating ceramic and similar mixtures, which contains mechanisms for forcing the mixture in the form of augers, conductive electrodes, and a power source, characterized in that, in order to ensure a uniform, post-controlled heating of the mixture, the conductive electrodes are annular, installed coaxially to augers, and flat, secured helix helix. 2. Device pop. 1, characterized in that all electrodes are autonomously connected to the power source through a switching unit. Sources of information taken into consideration during the examination: 1. Patent Czechoslovakia number 113924, cl. From 07c, 1965. 2. Avt. St. USSR № 343966, cl. From 0441/30. 1970 (prototype). Phi-g. t