System and technology used for double furnace double kettle stripping flash evaporation production of modified asphalt

Abstract

The invention relates to a system and technology used for double furnace double kettle stripping flash evaporation production of modified asphalt. The system comprises a reaction kettle No.1, an overflow buffer tank No.1, a tubular furnace No.1, a first asphalt circulation loop, a reaction kettle No.2, an overflow buffer tank No.22, a tubular furnace No.2, a second asphalt circulation loop; flexible blocking plate are arranged in the reaction kettle No.1 and reaction kettle No.2; the first asphalt circulation loop is provided with the overflow buffer tank No.1; and the second asphalt circulation loop is provided with the overflow buffer tank No.2. According to the system, a side feeding and lower discharging mode is changed to be a side feeding and overflowing discharging mode, the overflow buffer tanks are arranged behind the reaction kettles, reaction kettle flow out amount is controlled by maintaining the asphalt liquid level in the overflow buffer tanks to be stable, and at last, accurate control on reaction retention time is realized through controlling the liquid levels in the reaction kettles to be constant, and asphalt production long term smooth operation is realized.

Description

technical field [0001] The invention relates to the technical field of metallurgy and coking, in particular to a system and process for producing modified asphalt by stripping and flashing with double furnaces and double kettles. Background technique [0002] Coal tar processing generally produces about 50% to 60% of asphalt, which is a bulk product of tar processing. The larger the processing scale, the more asphalt output. Modified asphalt is currently the main downstream product of asphalt, which is mainly used in the electrolytic aluminum industry to produce prebaked anodes, prepare battery rods or electrode binders. [0003] At present, domestic production of modified asphalt mostly adopts thermal condensation polymerization method, which can be divided into kettle heating method and tube furnace heating method according to the heating method. [0004] The modified asphalt production process of kettle heating method uses medium temperature asphalt as raw material, the ...

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Problems solved by technology

[0006] The modified asphalt production process of the tube furnace heating method has become the mainstream of the modified asphalt production process due to its large design capability and flexible reaction control. However, there is a big problem that is difficult to solve, that is, the modification of the modified asphalt reactor. The problem of liquid level measurement, because the modified asphalt reactor achieves the purpose of asphalt modification by controlling the residence time and reaction temperature of the reactants, and the residence time is controlled by controlling the liquid level height of the reactor, so the liquid level measurement is a reaction key to process control

[0007] The traditional method of remote measurement of the liquid level of the reactor generally adopts the measurement method of pressure difference, which is converted into the liquid level height through the calculation of the density of the liquid. Due to solid suspensions such as polymers, liquids with high viscosity and easy to solidify, and asphalt smoke with large volatilization and easy condensation, the asphalt is easy to solidify and block at the liquid pressure measurement interface of the instrument, resulting in the failure of the measuring instrument

If a displacer liquid level gauge is used, the buoy and the deflector or the guide wire are likely to stick together and are not easy to float up and down, resulting in the failure of liquid level measurement

In addition, there are also attempts to use a float level gauge, but because the liquid level of the reactor is as high as 10m or more, the traditional float level gauge has a liquid level indicator at the same height as the liquid level, resulting in the float level gauge lifting rod being too large. Long, the liquid level indicator is too high on the top of the kettle and it is difficult to realize, and it also has the problem that the float and the guide tube or the guide wire are easy to stick together and not easy to float up and down

In addition, the asphalt smoke is easy to enter the liquid level indicator along the liquid level indicator lifting rod to condense, causing the liquid level indicator to block

If a radar level gauge is used, the short-term measurement effect is still possible, but because the asphalt smoke is easy to condense on the radar level gauge, it will soon cause the radar electromagnetic wave reception to fail, resulting in frequent maintenance

[0008] In the pressurized double furnace double kettle stripping flash process introduced from France, the liquid level height control of the reactor does not use the liquid level measurement method, but uses the weighing module to convert the liquid level height, by controlling the overall weight of the reactor To control the liquid level, and the number of measurement points of the weighing module is the key to the accuracy of the weight measurement. Generally, 2 measurement points are more accurate. The lugs of large reactors are usually 6 or 8. The measurement is not accurate, and often Affected by the wind load and the error of the weighing module, the weight measurement is unstable and fluctuates greatly, causing the converted liquid level to be unstable, causing the outflow of modified asphalt to fluctuate greatly, thus affecting the quality control of modified asphalt

At the same time, due to the huge shape of the reactor equipment, it is very difficult to overhaul and replace the weighing module, and the overhaul takes a long time, seriously affecting normal production

[0009] To sum up, the current production process of modified asphalt by the tube furnace heating method has not solved the problem of liquid level measurement in the reactor, so the automatic control of this process needs to be improved, and the process and equipment need to be improved.

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