RU151071U1 - DEVICE FOR DRYING WASTE WHEN PRODUCING FUEL BRIQUETTES - Google Patents

Abstract

A device for the manufacture of fuel briquettes from wastes of plant, organic, mineral and synthesized raw materials, containing a conveyor, an energy source, a protective chamber, characterized in that the low-potential electrodes are additionally installed on the conveyor, the role of which is played by the bottom of the loading containers at the moment of contact with the grounded base, press , the top plate of which is movable, to which a high-potential electrode is connected through an insulating gasket, connected through a power regulator to full-time RF energy.

Description

The utility model relates to devices for high-frequency drying and can be used for the manufacture of fuel briquettes from waste vegetable, organic mineral and synthesized raw materials.

Existing processing processes are associated with the processing of various wastes of plant, organic, mineral and synthesized raw materials. Due to differences in the technological processes for the production of waste, the conditions for their storage and transportation, they have various electrophysical, chemical and humidity indicators. One of the most important indicators of our time is the process of waste disposal and obtaining cheap energy. In this connection, there is a need to create drying and waste treatment devices.

A known method and device for vacuum drying of capillary-porous materials. The material is additionally exposed to the energy of mechanical vibrations of ultrasonic frequency. The device contains elements for heating the material and evacuation. The heating of the material is carried out by exposure to high-frequency electromagnetic field energy and / or the energy of mechanical vibrations of the ultrasonic frequency, while the material is heated, evacuated and the energy of the mechanical vibrations of the ultrasonic frequency is exposed to the material simultaneously (see Patent for invention RU No. 2168127, IPC F26B7 / 00, F26B5 / 02, F26B5 / 04, F26B3 / 34 declared, 07/02/1999). The disadvantage of this device is the need to create special vacuum chambers with the simultaneous supply of the energy of mechanical vibrations of ultrasonic frequency to them.

Known vacuum-dielectric drying chamber for wood, containing a sealed enclosure, a means for moving the wood stack, a vacuum system, cooling the chamber, collecting and draining condensate, as well as a high-frequency generator with a system for supplying high-frequency voltage to electrodes located in the housing half on both sides relative to side walls of the stack. The voltage supply system also includes busbars installed in contact with a large number of points in the upper part of each electrode, and the electrodes are adjacent to the side walls of the stack in its upper part and are located at an angle of 0.5-2.0 ° to the vertical with the formation between them and the side walls of the stack of gaps, the value of which increases in the direction from top to bottom (see Patent for invention RU No. 2040744, IPC F26B 3/34, F26B 3/347, F26B 5/04 claimed, 07/12/1994 g). The complex geometry of the connection of the electrodes and their large number, the presence of vacuum and the need to provide the generator with a cooling system make this device time-consuming and costly.

The closest in design features adopted as a prototype was a device for microwave drying of bulk materials (see Patent for invention RU 2073961, IPC H05B 6/64, H05B 6/80, F24C 7/02, F26B 3/32, F26B 3/34, claimed 10.08.1994 g). The essence of this device is that for microwave drying of bulk materials, microwave generators are used, connected to the heating chamber, loading and unloading tunnels connected to the heating chamber, the conveyor, consisting of sections formed by a conveyor and rectangular plates placed across the conveyor, have additional microwave generators, each microwave generator is connected through a section of the waveguide to the irradiator installed in the heating chamber above the conveyor, in a checkerboard pattern, the heating chamber is equipped with wife with quarter-wave chokes with an absorber located at the inlet and outlet of the heating chamber, the height of the rectangular plates does not exceed λ / 2, and the distance between the plates is greater than λ, where λ is the working wavelength.

The disadvantages of this device include the used microwave radiation that does not allow uniformly to dry dimensional products, because insignificant depth of penetration of microwave energy into the material. The operating mode of the microwave generator is maximum, because A feature of this type of equipment is the unregulated radiation power, which also does not depend on the electrophysical and chemical properties of the material being processed, or on its presence or on the completeness of loading of the heating chambers. The presence of chokes and absorbers, for the heating of which additional energy is expended, increases the inefficient energy consumption of the proposed device.

The technical task of the proposed utility model is to create a device for more complete drying and manufacture of fuel briquettes from waste of various sizes, vegetable, organic, mineral and synthesized raw materials

The technical solution of this problem is a device for drying and manufacturing fuel briquettes from waste of plant, organic, mineral and synthesized raw materials, having a radio frequency range generator connected to a heating working chamber, loading and unloading containers, connected alternately to the generator contacts in the working heating chamber, conveyor consisting of sections formed by a conveyor with installed loading and unloading containers located along the conveyor but of a useful model, an additional device for controlling the heating power (for example, a variable condenser), a press for preliminary dehydration (before drying) and subsequent (during the drying) crimping for direct formation of the fuel briquette are installed.

The technical result of the utility model is the ability to control the heating power, preliminary dehydration, uniformity of drying, reduction of energy consumption with ease of manufacture.

The specified technical result is achieved in that the device for the manufacture of fuel briquettes contains an RF generator that allows without additional elements (chokes and absorbers) to organize the transfer of energy through a coaxial line to the electrodes in direct contact with the processed material and located in the working chamber, where the energy is high frequency consumed only for heating the raw materials available between the electrodes, and the device is equipped with an RF energy regulator, which can be reduced or increased depending on production needs, while, unlike microwave processing, the RF heating process is selective and self-regulating (first of all, only moist material is heated, with a decrease in the moisture content of which its conductivity decreases and the RF heating process stops), moreover, HF radiation differs from microwave uniformity and a greater penetration depth, and the press installed in the working chamber performs preliminary pressure testing to dewater the material.

The essence of the device is illustrated by the drawing, where figure 1 shows a structural diagram of a device for drying and manufacturing of fuel briquettes from small fraction waste of plant, organic, mineral and synthesized raw materials.

The device comprises: a hopper-dispenser 1 for filling with the source material 2, loading and unloading containers 3, made in the form of prefabricated structures consisting of walls (in the form of a cylinder or other geometric shape from non-conductive materials) 4 and the bottom 5 made of perforated from a conductive material, installed in turn, with an interference fit into the technological openings 6 of the conveyor 7, the containers being installed along the entire length of the continuous conveyor (for example, circular) at a step distance L protected by a screen 8 made from aluminum sheet with metal strips 9 mounted in it for holding it in a closed position by means of electromagnets 10, a working heating chamber, 11, which in turn consists of a press 12 located in it, the rod 13 of which is connected to a movable plate 14, which the insulating gasket 15 is connected to the perforated plate 16 in size and shape entering the loading container, in close contact with its walls 4, and this plate through the flexible bus 17 and the coaxial cable 18 is connected indirectly through the regulator a power generator 19 with a high-frequency generator 20 and at the same time serves as a high-potential electrode, the lower part of the working chamber 21 is the base of the device, made of aluminum alloy, grounded and simultaneously performs the role of a low-potential electrode.

The operation of the device for drying waste in the manufacture of fuel briquettes is as follows.

After filling the loading and unloading tank with waste from the metering hopper, the conveyor is switched on and cycled along with the filled tank into the open working heating chamber. The displacement cycle V is determined by the distance L, which ensures the alignment of the loading and unloading tank of figure 2 and the upper perforated plate of figure 3. It should be noted that the loading and unloading tanks are made in the form of prefabricated structures consisting of walls (in the form of a cylinder or other geometric figure made of insulating materials) 4 and bottom 5 made of perforated from conductive material. The perforated bottom 5, made of copper alloy, the wall of a cylindrical shape 4, is made of insulating cardboard brand EVT, GOST 2824-86, a thickness of 0.4 mm. The walls are fastened with sliding clamps of a suitable diameter 23. This wall design allows you to increase the tolerances of misalignment of the loading tank 3 and the upper perforated plate figure 16, because the walls of the loading vessel made of insulating cardboard are flexible enough and compensate for misalignment errors during operation.

The upper perforated plate 16 in size and shape exactly corresponds to the cross-sectional shape of the loading and unloading tank 3 in the plane of the perpendicular axis and is connected to the movable upper plate 14 of Nressa 12, 13 through the insulating gasket 15, which, when turned on, tightly contacts its walls acts as a piston 16 providing pressure transfer to remove excess moisture from the processed material. Moisture removal is mainly carried out through the perforated bottom 23 of the prefabricated loading and unloading tank. The operating time and press force F is determined experimentally, at the end of intensive moisture separation and depends on the feedstock 2. According to experimental data (depending on the moisture content of the material), up to 10% of moisture is removed by pressing.

The RF generator is turned on after the pressing time has passed. The energy from the RF generator 20 through the power regulator 19, the coaxial cable 18 and the flexible bus 17 is transferred to the upper perforated plate 16. The electrothermal RF heating of the processed material, significantly exceeding the microwave heating in depth and intensity (Fig. 2), leads to removing the steam-water mixture from the processed material, the unhindered exit of which is mainly carried out through the upper perforated plate 16, which, after switching on the RF generator, acts as a high-potential electrode. The force F of the press is not removed, which ensures reliable contact of the perforated bottom 23 of the loading container 3 with the grounded base of the device 21 made of aluminum alloy, which allows the bottom 23 to simultaneously serve as a low-potential electrode.

The time of HF drying with simultaneous prepress forming a fuel briquette can be preliminarily determined based on the description of the Poiseuille fluid flow (1):

where r is the radius of the capillary, Δp is the pressure difference at the ends of the capillary, μ is the viscosity of the liquid, l is the length of the capillary.

Studies have established that, at speeds of 0-8 cm / s, the filtration flow has a laminar regime. At speeds of more than 8 cm / s, the laminar motion regime changes to turbulent mode, and the capillary resistance rises sharply. This shows the difficulties in performing calculations using this technique for practical use, therefore, the time of RF drying with simultaneous prepress was determined experimentally, taking into account the peculiarity of electrothermal heating using RF frequencies (for example, 27.12 MHz), the drying process is selective and self-regulating, when heating more intensively occurs in places with a high moisture content and stops automatically when it is removed.

For example, when pressing fuel briquettes from wood-sawdust pulp with a drying time of 17 seconds (using UZP 2500 equipment and anode current mode of operation 0.35 A and a pressure of 200 kg), fuel briquettes 20 mm thick were obtained. without the addition of any binders.

By pressing with high-frequency drying, modified fuel briquettes with the addition of polyethylene chips were obtained at a drying time of 29 seconds (using UZP 2500 equipment and anode current mode of operation of 0.35 A and a pressure of 200 kg), fuel briquettes 25 mm thick were obtained. To reduce the cost of the material, polyethylene chips were made from polyethylene waste that had already undergone repeated recycling, which underwent significant destructive changes during operation or was contaminated with non-toxic compounds that interfere with traditional methods of processing

Determination of the time of RF drying and dehydration of samples with a height of more than 50 mm was carried out using hydrolysis lignin as an example. Hydrolytic lignin has high humidity and has not yet been used. The starting material was heterogeneous; the sizes of individual particles reached 20–30 mm. The drying time was 40 seconds (on the equipment UZP 2500 and the mode of operation of the anode current of 0.35 A and a pressure of 200 kg).

The inclusion of the press is preceded by the mandatory lowering of the protective screen 8 while simultaneously holding it by magnetizing the plates 9 to the included electromagnets 10, which are de-energized after the end of the high-frequency drying and pressing process. Opening the screen 8 is carried out by a spring or other mechanism (not shown in the figure). Raising the screen to the upper position gives a signal for lifting the press and cyclic movement of the V conveyor 6 to a distance L, which allows loading and unloading tank 3 to be removed from the heating chamber 11 already with the finished fuel briquette 22 and at the same time to be introduced into the working chamber of the heating 11 filled loading and unloading tank 3. Removing the finished briquette is carried out in the cyclic time of pressing and high-frequency heating. The volume of briquettes 22 after drying is reduced and its removal from the loading and unloading tank 3 does not require additional devices.

For better moisture removal, the electrodes are made in the form of perforated plates, in the upper electrode 16, it is justified to increase the number and diameter of holes evenly distributed over the area for intensive removal of drying products. Using the basic laws of hydro- and aerodynamics and knowing the physical parameters of liquids and gases obtained during the drying process, it is possible to determine the optimal total cross-section of the holes for intensive removal of the drying products. Depending on the purpose of the fuel briquettes 22 and the conditions of their storage and transportation, various fillers can be included in the feedstock serving as an initiating substance for intensive and more complete combustion, or as a binder necessary to create a strength frame.

Claims (1)

A device for the manufacture of fuel briquettes from waste vegetable, organic, mineral and synthesized raw materials containing a conveyor, an energy source, a protective chamber, characterized in that the conveyor is additionally equipped with low-potential electrodes, the role of which is played by the bottom of the loading containers at the moment of contact with the grounded base, press , the top plate of which is movable, to which a high-potential electrode is connected through an insulating gasket, connected through a power regulator to full-time RF energy.

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