CN201686500U - A microwave rotary kiln for calcination of uranium chemical concentrate - Google Patents

Abstract

The utility model relates to a microwave rotary kiln used for calcination of uranium chemical concentrates. The equipment is mainly composed of high-level silo, feeding mechanism, discharging mechanism, microwave reaction chamber, microwave rotary kiln furnace, temperature measuring instrument, microwave power source, water cooling system, remote control system and other components. It is mainly used for calcination of uranium chemical concentrates. This equipment not only overcomes the problems of long cycle, high energy consumption, low thermal efficiency, poor product uniformity, easy occurrence of under-burning and over-burning of conventional calcination equipment, but also has uniform microwave field distribution and strong equipment stability. It is a uranium chemical Microwave equipment for large-scale and continuous production in the concentrate calcination process.

Description

A microwave rotary kiln for calcination of uranium chemical concentrate

1. Technical field

The utility model relates to a microwave rotary kiln for calcination of uranium chemical concentrates, in particular to a continuous and large-scale microwave heating equipment suitable for calcination of uranium chemical concentrates.

2. Background technology

At present, the known calcining of uranium chemical concentrates usually adopts a semi-dynamic electric calcining kiln represented by a drum. It is characterized in that heat is transferred from the outside to the inside of the material through conduction, convection, radiation, etc. Due to the uneven temperature distribution on the same section of the equipment, the production method has a long cycle, high energy consumption, low thermal efficiency, poor product uniformity, and prone to under-burning and over-burning, which will bring processing difficulties to subsequent processes. ; and more critically, the electric kiln calcining ammonium uranyl tricarbonate for a long time will lead to an increase in the threat of nuclear radiation. For example, in the process of preparing U3O8 by calcining ammonium uranyl tricarbonate provided by the patent CN1319848A, it needs to be raised from room temperature to 700-900°C at 300-500°C/hour, and the holding time is as long as 2-6 hours. Therefore, it is extremely important to develop a new type of calcination equipment that is fast, safe, and low in energy consumption.

As a green and efficient heating method, microwave can selectively heat materials through energy dissipation inside the materials. It has the advantages of uniform heating, high thermal efficiency, clean and pollution-free, etc. that cannot be compared with conventional heating methods. However, among the known microwave equipment, the refitted household microwave oven belongs to intermittent heating, has low power density and poor repeatability, and cannot carry out large-scale operations; for high-power high-temperature microwave equipment, although researches in this area have been carried out both at home and abroad, such as British EA Technology Company has established microwave high-temperature sintering equipment, and Canadian EMR Microwave Technology Company has established microwave pretreatment devices for chalcopyrite and arsenopyrite, but there are problems such as uneven distribution of microwave fields and poor airtightness of equipment. For example, the microwave sintering equipment provided by the patent CN1718790A, although it can meet the preparation of tricobalt tetroxide, has poor airtightness, single temperature field distribution in the reactor, and cannot realize the implantable calcination of uranium chemical concentrates. Therefore, the continuous and large-scale high-temperature microwave equipment that can be used for calcining uranium chemical concentrates is still blank. In addition, since the current microwave reactor power source system is mostly cooled by natural air cooling or forced air cooling, both natural air cooling and forced air cooling have low cooling efficiency and poor cooling effect, resulting in poor equipment stability and long service life. short.

To sum up, due to the lack of safe and stable dedicated microwave reactors, the scope of industrial application of microwave is narrow, and the supporting effect on the economy is not obvious. Therefore, the development of continuous and large-scale high-temperature microwave reactors plays an important role in leading the development of microwave in the nuclear energy industry in the future.

3. Contents of the invention

The purpose of the utility model is to provide a microwave rotary kiln for calcination of uranium chemical concentrate. In view of the disadvantages of conventional electric heating rotary kiln, such as long production cycle, high energy consumption, and poor product uniformity, and the existing microwave equipment, such as uneven distribution of microwave field, poor equipment stability, and short service life, etc., according to the large radiation hazard of uranium chemical concentrates , The airtightness of the equipment requires high specificity. The microwave rotary kiln provided is a kind of high-temperature microwave rotary kiln equipment suitable for calcination of uranium chemical concentrates, which can realize continuous and large-scale multi-stage temperature control.

The utility model is implemented according to the following technical scheme, which includes a high-level hopper 1, a feeding mechanism 2, a smoke exhaust system 3, a microwave reaction chamber 4, a microwave rotary kiln hearth 5, a discharging mechanism 6, a remote control system 7, and a microwave power Source 8, water cooling system 9, insulation layer 10, thermometer 11. The high-level silo 1 is placed at the feeding end of the microwave reaction chamber 4, and its lower part is connected with the feeding mechanism 2. The feeding mechanism adopts a spiral feeding method, and the feeding spiral is connected with the speed-regulating motor through a chain. The microwave reaction chamber 4 is The reaction chamber of a regular pentahedron, the microwave power source 8 is equipped with a water cooling system 9 arranged around the microwave reaction chamber 4, the water cooling system 9 is assembled on the microwave power source 8 using an aluminum alloy annular water cooler, and the two ends of the microwave rotary kiln furnace 5 A steel jacket is provided, and gears are mounted on the jacket. The gears are connected to the speed-regulating motor through a chain to drive the microwave rotary kiln hearth 5 to rotate. The installation slope of the microwave rotary kiln hearth 5 is 3-10 degrees. It is connected with the discharge end of the microwave rotary kiln hearth 5, and the feeding mechanism 2 and the discharge mechanism 6 are sealed with the microwave rotary kiln hearth 5 with a graphite sealing ring. The microwave rotary kiln hearth 5 is covered with an insulation layer 10, and the microwave Smoke exhaust system 3, one end is fixedly connected to the feed end, and the other end is connected to the smoke exhaust pipe. The microwave rotary kiln furnace 5 is equipped with a thermometer 11 at the discharge end, and adopts an independent PID (proportional-integral-differential) three-stage module The thermocouple for temperature control and temperature measurement adopts three-point combined temperature measurement, and the microwave rotary kiln is controlled by the remote control system 7 .

When working, put the material into the high-level hopper, turn on the in-out material switch, adjust the feeding screw speed, and the material is continuously transported into the microwave reaction chamber through the feeding screw, and the microwave is turned on after the material is covered with the microwave rotary kiln and reaches a certain thickness. The heating switch adjusts the microwave output power so that the materials are raised from room temperature to the predetermined temperature at a certain heating rate. The materials pass through the entire rotary kiln chamber slowly from the feed end of the rotary kiln, and are discharged and recovered by the discharge mechanism after microwave treatment. The gas is exhausted by the smoke exhaust system.

Advantages and positive effects of the utility model

(1) Through the simulation optimization of the microwave reaction chamber, the microwave reaction chamber adopts a regular pentahedron design, so that the cross-coupling between microwave sources is minimized, and the microwave field in the cavity is more uniform;

(2) The microwave magnetron adopts aluminum alloy annular water cooling method, which improves the stability of the equipment and prolongs the service life of the equipment;

(3) The graphite sealing ring is used to seal between the microwave reaction cavity feeding and discharging mechanism and the furnace to ensure the airtightness of the furnace;

(4) Based on the characteristics of microwave "body heating", the whole material is heated evenly, the product composition and particle size are uniform, and the production cycle is short;

(5) The microwave reaction chamber is controlled by the PLC remote control system, which avoids possible damage to the human body caused by microwave leakage.

4. Description of drawings

Fig. 1 is a structural diagram of the utility model, in which, 1 is a high-level silo, 2 is a feeding mechanism, 3 is a smoke exhaust system, 4 is a microwave reaction chamber, 5 is a microwave rotary kiln hearth, and 6 is a discharge mechanism , 7 is a remote control system, 8 is a microwave power source, 9 is a water cooling system, 10 is an insulation layer, and 11 is a thermometer.

5. Specific implementation

According to the structure shown in Figure 1, it includes a high-level silo 1, a feeding mechanism 2, a smoke exhaust system 3, a microwave reaction chamber 4, a microwave rotary kiln hearth 5, a discharging mechanism 6, a remote control system 7, and a microwave power source 8. Water cooling system 9, insulation layer 10, thermometer 11. The high-level silo 1 is placed at the feeding end of the microwave reaction chamber 4, and its lower part is connected with the feeding mechanism 2. The feeding mechanism adopts a spiral feeding method, and the feeding spiral is connected with the speed-regulating motor through a chain. The microwave reaction chamber 4 is The reaction chamber of a regular pentahedron, the microwave power source 8 is equipped with a water cooling system 9 arranged around the microwave reaction chamber 4, the water cooling system 9 is assembled on the microwave power source 8 using an aluminum alloy annular water cooler, and the two ends of the microwave rotary kiln furnace 5 A steel jacket is provided, and gears are mounted on the jacket. The gears are connected to the speed-regulating motor through a chain to drive the microwave rotary kiln hearth 5 to rotate. The installation slope of the microwave rotary kiln hearth 5 is 3-10 degrees. It is connected with the discharge end of the microwave rotary kiln hearth 5, and the feeding mechanism 2 and the discharge mechanism 6 are sealed with the microwave rotary kiln hearth 5 with a graphite sealing ring. The microwave rotary kiln hearth 5 is covered with an insulation layer 10, and the microwave Smoke exhaust system 3, one end is fixedly connected to the feed end, and the other end is connected to the smoke exhaust pipe. The microwave rotary kiln furnace 5 is equipped with a thermometer 11 at the discharge end, and adopts an independent PID (proportional-integral-differential) three-stage module The thermocouple for temperature control and temperature measurement adopts three-point combined temperature measurement, and the microwave rotary kiln is controlled by the remote control system 7 .

Claims (1)

1. one kind is used for uranium chemical concentrate incinerating microwave rotary kiln, it is characterized in that: it comprises high hopper (1), feed mechanism (2), fume exhaust system (3), microwave reaction cavity (4), microwave rotary kiln burner hearth (5), discharging mechanism (6), tele-control system (7), microwave power source (8), water-cooling system (9), thermal insulation layer (10), temperature measurer (11), high hopper (1) places microwave reaction cavity (4) feed end, its underpart is connected with feed mechanism (2), feed mechanism adopts the spiral way charging, feed auger links to each other with buncher by chain, microwave reaction cavity (4) is a regular five-hedron, microwave power source (8) configuration water-cooling system (9) be arranged in microwave reaction cavity (4) around, water-cooling system (9) adopts aluminium alloy annular water cooler to be assemblied on the microwave power source (8), microwave rotary kiln burner hearth (5) two ends are provided with the steel chuck, the centre puts and is equipped with gear, gear is connected driving microwave rotary kiln burner hearth (5) by chain and rotates with buncher, the installation gradient of microwave rotary kiln burner hearth (5) is the 3-10 degree, discharging mechanism (6) is connected with microwave rotary kiln burner hearth (5) discharge end, seal with graphite-seal ring between feed mechanism (2) and discharging mechanism (6) and the microwave rotary kiln burner hearth (5), the outer thermal insulation layer (10) that covers of microwave rotary kiln burner hearth (5), microwave rotary kiln burner hearth fume exhaust system (3) one ends are fixedlyed connected with feed end, the other end is connected with smoke exhaust pipe, microwave rotary kiln burner hearth (5) discharge end is equipped with temperature measurer (11), adopt independently PID three root module temperature controls, temperature thermocouple adopts 3 built-up type thermometrics, and the microwave rotary kiln is by tele-control system (7) control.

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