Mineral aggregate drying and calcining equipment

Abstract

The utility model discloses mineral aggregate drying and calcining equipment which comprises a shell and a lifting mechanism installed in the shell, a feeding port and a discharging port are formed in the lower portion and the upper portion of the shell respectively, a microwave heating area is arranged between the feeding port and the discharging port, and the shell of the microwave heating area is connected with a plurality of microwave energy feedback systems. The microwave energy feedback system is connected with the microwave generator; the lifting mechanism comprises a driving wheel, at least one driven wheel, a conveying belt and a plurality of feeding hoppers. The driving wheel is externally connected with a motor and installed on the shell. The transmission belt is wound on the driving wheel and the driven wheel, and the plurality of feeding hoppers are fixed on the transmission belt. The mineral drying and calcining device is simple in structure and low in cost, when the mineral drying and calcining device is used, mineral materials are dried or calcined while being lifted to a next storage tank or a next process unit, and the problems of long technological process, large equipment size and high energy consumption and emission due to the fact that special equipment needs to be independently arranged in the mineral drying and calcining process in a conventional production method are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of mineral material processing equipment, and in particular relates to equipment for microwave drying and calcining mineral materials. Background Art

[0002] Drying and calcination are important links in the processing and application of inorganic minerals such as gypsum. Usually, technical equipment such as coal-fired or gas-fired boiling furnaces, rotary kilns or hot steam indirect heat exchange furnaces are used to dehydrate, dry or further calcine the mineral powder. These equipment and their production process methods have large production capacity and high efficiency, but there are problems such as large equipment footprint, high energy consumption, and high investment and operating costs. In addition, due to uneven heating, the mineral powder is often not completely dehydrated or over-burned after drying or calcination, and the quality is difficult to stably meet the requirements. In addition, the use of fossil fuels for heating during drying and calcination will also produce a large amount of harmful flue gas that needs to be treated, and the carbon emissions are very high. When using hot steam for heating, an external steam source pipeline is required, and the heat transfer efficiency is low, the conditions are limited, and the cost is high.

[0003] Microwave drying has been effectively applied in some industries to remove mineral moisture, but microwave direct drying or calcination of mineral powder is not ideal. Since a considerable number of inorganic minerals have poor microwave absorption, high requirements are placed on microwave drying equipment, and usually separate microwave drying and calcination equipment such as microwave tunnel kilns and push plate kilns occupy a lot of space, and the investment in processing technology is high. In order to achieve efficient moisture removal without affecting the properties of the mineral, and to effectively solve the problems of large size, high energy consumption, and large exhaust gas emissions of current mineral drying and calcination equipment, as well as the poor effect of conventional microwave equipment in treating minerals, it is necessary to innovate and improve traditional drying and calcination equipment. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a mineral material drying and calcining equipment which has a simple structure, is easy to operate, saves energy and reduces carbon, can shorten the process flow and occupies a small area.

[0005] The technical solution adopted by the utility model is: a mineral material drying and calcining equipment, comprising a shell and a lifting mechanism installed in the shell, the lower part and the upper part of the shell are respectively provided with a feed port and a discharge port, a microwave heating zone is arranged between the feed port and the discharge port, the shell of the microwave heating zone is connected to a plurality of microwave energy feeding systems, and the microwave energy feeding systems are connected to a microwave generator;

[0006] The lifting mechanism includes a driving wheel, at least one driven wheel, a transmission belt and a plurality of feeding hoppers. The driving wheel is externally connected to a motor installed on a shell; the transmission belt is wrapped around the driving wheel and the driven wheel, and the plurality of feeding hoppers are fixed on the transmission belt; the feeding hopper loads materials at a feed port and discharges materials at a discharge port; and a microwave energy feeding system irradiates materials and feeding hoppers with microwaves.

[0007] Furthermore, the bottom of the shell is fixedly mounted on the frame.

[0008] Furthermore, the vertically arranged side wall of the shell is an insulating jacket structure composed of an outer wall, an interlayer and an inner wall; a temperature measuring device is fixed on the shell of the microwave heating zone, and the temperature measuring device includes an infrared temperature measuring device and a thermocouple temperature measuring probe, and the temperature measuring device is connected to the controller of the microwave generator.

[0009] Furthermore, the microwave energy feeding system is installed on the side wall of the shell parallel to the axis of the driving wheel, and the front end of the microwave energy feeding system penetrates the side wall of the shell to irradiate the feeding hopper and materials on the conveyor belt; the irradiation is perpendicular to the facade or at an acute angle to the facade to ensure that the feeding hopper and materials are irradiated.

[0010] Furthermore, an electric auxiliary heating device is provided at the upper part and / or the lower part of the microwave heating zone, and the electric auxiliary heating device is installed on the frame or in the interlayer of the outer shell, and the electric auxiliary heating device is used for electrically assisting preheating of the feeding hopper and the material therein.

[0011] Furthermore, the single power of the microwave generator is 2-100 kW, and the frequency is 915 MHz or 2450 MHz; the single power of the electric auxiliary heating device is 2-50 kW.

[0012] Furthermore, part or all of the feeding hopper is made of wave-absorbing material, the outer wall of the shell is made of metal, the interlayer is made of aluminum silicate, rock wool or alumina, and the inner wall is made of all or part of the wave-absorbing material; the wave-absorbing material includes one or a mixture of quartz, alumina, graphite, silicon carbide, and zirconium oxide.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] (1) When the utility model is used, the hopper containing the mineral powder is conveyed upward, and under the action of microwave feeding and rapid heating, the mineral powder in the hopper is dried to free water or calcined and decomposed, and the drying or calcination treatment is completed while the mineral powder is lifted to the next storage tank or process unit, thereby solving the problems of long process flow, large equipment volume and high investment in conventional production methods, which require separate special equipment for mineral drying and calcination processes.

[0015] (2) The utility model has a simple structure and low cost. The vertical structure it adopts makes its layout compact, saves site occupation area, and also reduces microwave radiation leakage.

[0016] (3) The utility model is a continuous production method with fast temperature rise and start and stop, and adopts a synergistic heating method of internal energy and conduction. It can accurately control the dehydration temperature of mineral materials such as gypsum, and avoid quality problems caused by under-burning or over-burning during mineral decomposition.

[0017] (4) The utility model can adopt green electric energy, and does not need to deal with the flue gas pollution caused by burning coal, gas, oil and biomass fuels, thus saving energy and reducing carbon emissions, and having a significant environmental protection effect.

[0018] (5) The utility model adopts all-electric drive and electric heating, which can be easily integrated with industrial automation control and big data systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model.

[0020] In the figure: 1-frame, 2-housing, 3-feeding port, 4-discharging port, 5-microwave heating zone, 6-microwave energy feeding system, 7-microwave generator, 8-driving wheel, 9-driven wheel, 10-transmission belt, 11-feeding hopper, 12-temperature measuring device, 13-electric auxiliary heating device. DETAILED DESCRIPTION

[0021] The utility model is further described below in conjunction with the accompanying drawings.

[0022] like Figure 1 As shown, the utility model includes a frame 1, a shell 2 and a lifting mechanism installed in the shell 2, and the bottom of the shell 2 is installed on the frame 1. The lower part and the upper part of the shell 2 are respectively provided with a feed port 3 and a discharge port 4. The lifting mechanism includes at least one driving wheel 8, one driven wheel 9 (the number of driven wheels 9 can be multiple), a conveyor belt 10 and a plurality of feeding hoppers 11, and the driving wheel is externally connected to a motor and installed on the shell 2 or the frame 1. The conveyor belt 10 is wrapped around the driving wheel 8 and the driven wheel 9, and the driving wheel 8 drives the driven wheel 9 to rotate through the conveyor belt, and with the help of the feeding hopper 11 moving with the conveyor belt 10, the material is lifted from the ground and below the ground to a certain height above the ground, and then transferred to the subsequent storage bin or other unit equipment. The opening directions of the feed port 3 and the discharge port 4 are opposite. The plurality of feeding hoppers 11 are fixed on the conveyor belt 10; the feeding hopper 11 loads the material at the feed port 3 and discharges the material at the discharge port 4.

[0023] The microwave heating zone 5 is located between the feed port 3 and the discharge port 4 in the shell 2. Three microwave energy feeding systems 6 (the number of microwave energy feeding systems 6 may be less than or more than 3) are arranged on the shell 2 at the microwave heating zone 5. The microwave energy feeding system 6 is connected to the microwave generator 7. The microwave energy feeding system 6 is installed on the side wall of the shell parallel to the axis of the driving wheel 8. The front end of the microwave energy feeding system 6 penetrates the side wall of the shell and irradiates the feeding hopper 11 on the conveyor belt and the materials therein; the irradiation is perpendicular to the facade or at an acute angle to the facade to ensure that the feeding hopper 11 and the materials therein are irradiated. An electric auxiliary heating device 13 is arranged at the lower part of the microwave heating zone 5 (the electric auxiliary heating device 13 may also be arranged at the upper part of the microwave heating zone 5). The electric auxiliary heating device 13 is installed in the interlayer of the shell 2. The electric auxiliary heating device 13 is used for electric auxiliary preheating of the feeding hopper and the materials therein.

[0024] The single power of the microwave generator 7 is 20 kW (a microwave generator of 2-100 kW can be selected), and the frequency is 2450 MHz. The vertically arranged side wall of the outer shell 2 is a jacket structure consisting of an outer wall, an interlayer and an inner wall. The outer wall is made of metal 316 stainless steel, the interlayer is filled with thermal insulation materials such as aluminum silicate or rock wool insulation, and the inner wall is made of silicon carbide and quartz absorbing materials. The absorbing material is one or a mixture of quartz, alumina, graphite, silicon carbide, and zirconium oxide. The power of the electric auxiliary heating device 13 is 10 kW (a 2-50 kW electric heating device can be selected), and several groups of electric heating rods of the electric auxiliary heating device 13 are installed in the interlayer of the outer shell 2 to realize the electric auxiliary preheating of the feeding hopper and the material therein. The temperature measuring device 12 adopts optical infrared temperature measurement, and the temperature measuring probe is inserted into the microwave heating zone 5. Its temperature signal is connected to the microwave transmitter 7 to realize temperature monitoring and microwave power input adjustment. The feeding hopper 11 is entirely made of silicon carbide wave absorbing material (the feeding hopper 11 may also be only partially made of silicon carbide wave absorbing material). The utility model adopts a power supply method that combines coal-fired power industrial power grid and new energy power grid such as industrial green microgrid, and can flexibly switch between the two power grids. During normal production, green electricity such as photovoltaic and wind power is used, and coal power is used as a supplement, thereby achieving significant energy-saving and carbon-reducing effects in the production process.

[0025] Working principle of the utility model: When the utility model is used to dry or calcine the powder of the ore, the motor drives the driving wheel 8 to rotate, so that the transmission belt 10 drives the driven wheel 9 to realize the upward and downward movement of the feeding hopper 11. The powder of the ore enters from the feed port 3, is received by the feeding hopper 11 from bottom to top, and enters the electric auxiliary preheating zone as the feeding hopper 11 is lifted vertically upward, and enters the microwave heating zone 5 after being preheated by the electric auxiliary heating device. The microwave generator 7 feeds microwave energy to the feeding hopper and the powder of the ore contained therein through the microwave energy feeding system 6 and its front end, excites the high-frequency vibration and heat release of the internal energy of the wet ore molecules, and at the same time, the absorbing material of the feeding hopper also absorbs the wave and releases heat and conducts the heat to the powder of the ore, the temperature of the powder of the ore rises rapidly, and the free water evaporates and dries. When the temperature reaches and exceeds the critical temperature, the ore crystals decompose. By temperature monitoring and control of the power input size of the microwave generator, the free water content in the ore can be accurately controlled. The powder of the ore after drying or calcination is sent out from the discharge port 4 and enters the silo or the next process unit. The wet steam and water are discharged from the discharge port 4 at the top of the equipment or the additional outlet.

Claims

1. A mineral material drying and calcining device, comprising a housing (2) and a lifting mechanism installed in the housing (2), wherein a feed inlet (3) and a discharge outlet (4) are respectively provided at the lower part and the upper part of the housing (2), wherein: A microwave heating zone (5) is provided between the feed port and the discharge port, the shell (2) of the microwave heating zone is connected to a plurality of microwave energy feeding systems (6), and the microwave energy feeding systems are connected to a microwave generator (7); The lifting mechanism comprises a driving wheel (8), at least one driven wheel (9), a conveyor belt (10) and a plurality of feeding hoppers (11); the driving wheel is externally connected to a motor and is mounted on a housing (2); the conveyor belt (10) is wrapped around the driving wheel and the driven wheel; the plurality of feeding hoppers (11) are fixed on the conveyor belt (10); the feeding hopper (11) loads material at a feed port (3) and discharges material at a discharge port (4); and a microwave energy feeding system (6) irradiates the material and the feeding hopper (11) with microwaves.

2. The ore drying and calcining equipment according to claim 1 is characterized in that: The bottom of the housing (2) is fixedly mounted on the frame (1).

3. The ore drying and calcining equipment according to claim 1 is characterized in that: The vertically arranged side wall of the shell is a heat-insulating jacket structure composed of an outer wall, an interlayer and an inner wall; a temperature measuring device (12) is fixed on the shell of the microwave heating zone, and the temperature measuring device includes an infrared temperature measuring probe and / or a thermocouple temperature measuring probe, and the temperature measuring device (12) is connected to the controller of the microwave generator.

4. The ore drying and calcining equipment according to claim 1 is characterized in that: The microwave energy feeding system (6) is mounted on a side wall of the housing parallel to the axis of the driving wheel (8), and the front end of the microwave energy feeding system (6) penetrates the side wall of the housing to irradiate the feed hopper and materials on the conveyor belt; the irradiation is perpendicular to the vertical surface or at an acute angle to the vertical surface, ensuring that the feed hopper and materials are irradiated.

5. The ore drying and calcining equipment according to claim 1 is characterized in that: An electric auxiliary heating device (13) is arranged at the upper part and / or the lower part of the microwave heating zone. The electric auxiliary heating device (13) is installed in the interlayer of the outer shell. The electric auxiliary heating device (13) is used for electrically assisting preheating of the feeding hopper and the material therein.

6. The ore drying and calcining equipment according to claim 3, characterized in that: The single power of the microwave generator is 2-100 kW, and the frequency is 915 MHz or 2450 MHz; the single power of the electric auxiliary heating device is 2-50 kW.

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