The invention provides a kind of simple method that suppresses to vaporize on the restriction.
For achieving the above object, hydrocarbon feed pyrolytic process according to the present invention comprises: heating raw under the temperature range of the pressure range 0.2 to 5Mpa and 390 to 530 ℃; Raw material is sent into reaction chamber; Logistics from reaction chamber is separated into light product stream and heavy product flow; To weigh product flow and send into vacuum tower, so that heavy product flow is separated into different fractions under the temperature range of 1 to 10kpa pressure range and 320 to 400 ℃, wherein, provide heavy product flow to comprise to vacuum tower: heavily restriction is crossed in products in circulation, upwards through vertical tube, the length of vertical tube should make vertical tube end fluid pressure energy suppress the vaporization of vertical tube lower end, heavy product flow then flows into vacuum tower through transfer lime, and the structure of transfer lime should make its exit hydrodynamicpressure equate with hydrodynamicpressure in the vacuum tower.
Word in specification sheets and claims " structure of transfer lime " be used to refer to transfer lime help to produce characteristics along the pressure drop of transfer lime, resemble size and the bend pipe in other flow resistance such as the transfer lime or the turnover of U type of transfer lime.
By example the present invention is described in more detail referring now to accompanying drawing, wherein,
About accompanying drawing 1.The flow process of the method according to this invention comprises process furnace 1 that has roasting kiln 2 and chimney 3 and the heating tube 4 that places process furnace 1.Heating tube 4 is connected on inlet tube 7 and the outlet pipe 9.
Outlet pipe 9 is connected on the inlet of reaction chamber 15.Reaction chamber 15 has more clearly been described among the European patent No.7656.The outlet of reaction chamber 15 is connected on the separating device by managing 17, and promptly cyclonic separator 20.
Cyclonic separator 20 has two outlets, and one is light product outlet 21, and another is heavy products export 24.Light product outlet 21 is connected to the equipment (not shown) that is used for further handling light product by the pipeline (not shown).Heavy products export 24 is connected on the vacuum tower 30 by piping 26.
Vacuum tower 30 has 32, one intermediate product cuts of 31, one heavy product resistates outlet pipes of outlet pipe outlet pipe 33 that is connected on the vacuum pump (not shown).Suitable backflow is provided and provides the equipment of stripping medium not express to vacuum tower 30 tops to vacuum tower 30 bottoms.
Piping 26 comprises and is provided with the pipeline section 35 that restriction is a flowrate control valve 36, is connected in the vertical tube 38 on the pipeline section 35 and feeds the transfer lime 40 of vacuum tower 30.
The length of vertical tube 38 is decisions like this, in normal running, makes vertical tube 38 lower end fluid pressure energies suppress the vaporization of vertical tube lower end fluidic.In specification sheets and claims, use " vaporization of suppression fluid " words and phrases to be meant small volume of fluid vaporization (being lower than about 5% (volume)) is arranged at the most.
The structure of transfer lime 40 is like this decisions, and under normal operation, the hydrodynamicpressure of transfer lime 40 exit end 41 equates with hydrodynamicpressure in the vacuum tower 30.This means that the design of transfer lime 40 makes the suffered friction of fluid of flowing through transfer lime 40 equal the pressure reduction of 30 of the exit of vertical tube 38 and vacuum towers.In the case, transfer lime 40 comprises some straight tubes 43 that the crooked pipe connecting in order to the form of U type pipe connecting 44 is connected.
In the normal running, providing continuously 3000 tons/day hydrocarbon feed under the pressure of 3Mpa in process furnace 1, hydrocarbon feed heats under 450 ℃ the temperature in process furnace 1.Then, the hydrocarbon feed of heating is sent into reaction chamber 15, hydrocarbon feed is in this cracking.In cyclonic separator 20, be separated into from exporting 21 900 tons/day light products that shift out and from the product flow of reaction chamber 15 from exporting 24 2100 tons/day heavy products that shift out, provide heavy product by piping 26 to the vacuum tower of under 5kpa pressure and 380 ℃ of temperature, operating 30, in vacuum tower 30, heavy product flow is separated into 200 tons/day the gaseous fraction that shifts out from outlet pipe 31,400 tons/day the middle runnings of shifting out from outlet pipe 33,1500 tons/day the resistates that shifts out from resistates outlet pipe 32.
Pressure drop on the flowrate control valve 36 is 150KPa.
The length of vertical tube 38 is 15n, and there is the fluidic vaporization that has prevented at the dirty end place of flowrate control valve 36 in fluidic in the vertical tube 38.
The length of transfer lime 40 is 70m, and the mean inside diameter of transfer lime 40 is 50cm, and transfer lime comprises 4 U type pipe connectings.The ingress hydrodynamicpressure of transfer lime 40 is 60kpa, and the exit hydrodynamicpressure equates with hydrodynamicpressure in the vacuum tower 30.
Save vertical tube 38 and will cause in flowrate control valve 36 places or near the vaporization it, this vaporization is uncontrolled and is accompanied by the formation of minimum drop.
Relate to accompanying drawing 2 now, another flow process of sending fully of its expression the method according to this invention.The part similar with the flow process described in the accompanying drawing 1 has identical reference number.
In the flow process of accompanying drawing 2, in distillation tower 50, be separated into from exporting the 51 light products streams that shift out and from exporting the 52 heavy product flow that shift out from the logistics of reaction chamber 15.
Then, provide heavy product flow by piping 26 to vacuum tower 30.Suitable backflow is provided and provides the equipment of stripping medium not express to distillation tower 50 tops to distillation tower 50 bottoms.
Crooked pipe connecting 44 can have the U type shown in attached Fig. 1 and 2, perhaps has the L type.
There is the fluidic vaporization that has prevented at the dirty end of restriction place in fluidic in the vertical tube.Save vertical tube and will cause at the restriction place or near the vaporization it, this vaporization is uncontrolled and is accompanied by the formation of very little drop.In vacuum tower, this this fine droplet can not be separated from air-flow, so that drop carried secretly out by the cut that leaves vacuum tower from middle cut outlet pipe, is perhaps left the air-flow of vacuum distilling top of tower from outlet pipe and carries secretly out.This separation efficiency of carrying secretly vacuum tower produces adverse influence.
As the described vertical tube 38 of attached Fig. 1 and 2 are standpipes, and certainly, this vertical tube also can be an inclined tube, as long as there are enough fluids to prevent devaporation in normal running in the vertical tube.