Structure of tubular reactor

A continuous operation reactor in the shape of a tube with a large aspect ratio. This reactor can be very long, such as propylene dimerization reactor tube length in kilometers. The structure of the reactor can be a single tube or multiple tubes in parallel; it can be an empty tube, such as a tubular cracker, or a filled tube filled with granular catalyst for multiphase catalytic reactions, such as a columnar-tube fixed-bed reactor. Usually, when the reaction stream is in a turbulent state, the length-to-diameter ratio of the empty tube is greater than 50; the ratio of the length of the filled section to the particle size is greater than 100 (for gas) or 200 (for liquid), and the flow of the material can be approximated as a flat push flow.

①Tube reactor. Composed of empty or filled tubes of relatively large length and diameter, it can be used to realize gas-phase reaction and liquid-phase reaction.

②Kettle reactor. By a relatively small diameter cylindrical container, often equipped with mechanical stirring or air stirring device, can be used for liquid-phase single-phase reaction process and liquid-liquid phase, gas-liquid phase, gas-liquid solid-phase multi-phase reaction process. Used for gas-liquid phase reaction process is called bubble stirring kettle (see bubble reactor); used for gas-liquid solid phase reaction process is called stirred kettle slurry reactor.

3) reactor with a bed of solid particles. Gas or (and) liquid through a fixed or moving bed of solid particles in order to realize the multiphase reaction process, including fixed bed reactor, fluidized bed reactor, moving bed reactor, trickle bed reactor, etc..

④Tower reactor. Used to realize the gas-liquid phase or liquid-liquid phase reaction process tower equipment, including filling tower, plate tower, bubble tower, etc.

1, water-heated reactor

When the temperature requirements are not high, can be used in this way of heating. There are two kinds of heating system: open type and closed type.

Open type is simpler, it consists of circulating pumps, tanks, pipes and control valves regulator. When high pressure water is used, the mechanical strength of the equipment requires high, the outer surface of the reactor kettle is welded on the snake tube, the snake tube and the kettle wall has a gap, so that the thermal resistance increases, and the heat transfer effect is reduced.

2, steam heating kettle

Heating temperature below 100 ℃, can be heated by steam below one atmosphere; when the heating range is 100-180 ℃, saturated steam; when the temperature is higher, high pressure superheated steam can be used.

3, other media heating reactor

If the process requirements must be operated at high temperatures, or to avoid the use of high-pressure heating system, can be used in place of other media to replace water and steam, such as mineral oil (275-300 ° C), benzene ether mixture (boiling point of 258 ° C), molten salts (140-540 ° C), liquid lead (melting point of 327 ° C) and so on.

4, electrically heated reactor

The resistance wire wound in the reactor barrel insulation, or installed in the reactor from a number of distances from the ad hoc insulator, you can use electricity to heat the reaction. The first three methods to obtain high temperatures are required in the kettle body additional jacket, due to temperature changes in the magnitude of the kettle jacket and shell to withstand temperature changes and temperature difference pressure.

When electric heating is used, the equipment is lighter and simpler, the temperature is easier to adjust, and there is no need for pumps, furnaces, chimneys and other facilities, and it is very simple to start, the danger is not high, and the cost is low, but the operation cost is higher than other heating methods, and the thermal efficiency is less than 85%, so it is suitable for the heating temperature of less than 400 ℃ and the price of electric energy is low.