TW200909572A - Process and apparatus for steam cracking hydrocarbon feedstocks - Google Patents

Abstract

The present disclosure provides a process for treating a hydrocarbon feedstock comprising: (a) feeding the hydrocarbon feedstock at a linear velocity equal to or less than 0.9 m/s to a first preheating zone in the convection section of a steam cracking furnace; (b) preheating the hydrocarbon feedstock in the first preheating zone to vaporize less than 99 wt.% of the hydrocarbon feedstock to form a vapor-liquid mixture; (c) separating at least a portion of the vapor-liquid mixture to form a vapor fraction and a liquid fraction; and (d) feeding at least a portion of the vapor fraction to the steam cracking furnace.

Description

200909572 IX. RELATIONSHIP BETWEEN OTHER APPLICATIONS This application claims the benefit and priority of International Patent Application Serial No. PCT/US2007/018486, filed on August 21, 2007. TECHNICAL FIELD The present disclosure relates to a method for producing a light anaerobic hydrocarbon in a steam cracking furnace or a pyrolysis furnace, and more particularly, the steam cracking contains at least 0. A method of hydrocarbon feed of 01% by weight of a low volatility compound. [Prior Art] Steam cracking, also known as pyrolysis, has long been used to crack different hydrocarbon feedstocks into olefins, preferably light olefins such as ethylene, propylene and butene. Traditional steam cracking utilizes a steam cracking furnace with two main sections: the convection section and the radiant section. The hydrocarbon feed is often fed into the convection section of the furnace in liquid form (other than a light feed entering in the form of a vapor), wherein the hot flue gas of the radiant section is typically in indirect contact and heated in direct contact with the steam. And the hydrocarbon feed is evaporated. The evaporated feed and steam mixture is then added to the radiant section where the cracking takes place. The resulting product, including olefins, is retained in the steam cracker for further downstream processing. Conventional steam cracking systems are effective in cracking local quality feeds such as natural gas liquids (NGL), gas oils and light oils. However, the steam cracking economy sometimes prefers to crack as in a non-limiting way, the low-cost heavy feed of the concentrate. The heavy feed is a small amount of gas and gas in the natural gas field, often -5-200909572 Atmospheric resid, also known as the production of atmospheric pipestill bottom and vacuum gas oil, crude oil, vacuum gas oil and atmospheric heavy oil contain high molecular weight. A low volatility component having a boiling point in excess of 590 ° C and/or a coke precursor sometimes having a boiling point in excess of 760 ° C. The low volatility components and/or coke precursors of these feeds will be deposited as coke in the convection section of a conventional steam cracking furnace as the light components evaporate. Downstream of the convection section where the light components are completely evaporated can only tolerate very small amounts of low volatility components and coke precursors, as this coke deposit will normally foul the tubes in the convection section, reducing heat transfer efficiency and increasing the pressure in the tubes. drop. In addition, some light oils are contaminated by heavy crude oils containing low volatility components and coke precursors. Conventional steam crackers do not handle residues, crude oil or many of the gas or light oils that are contaminated with residue or oil contaminated with low volatility and coke precursors. In order to solve the problem of coking, U.S. Patent No. 3,6, 7, 4, 3, the disclosure of which is hereby incorporated by reference herein in A second flash tank is used to remove vapor having a boiling point between 203 and 590 °C. The vapor is cracked into olefins in a steam cracker and the separated liquid from the second flash tank is removed, washed with steam, and used as a fuel. U.S. Pat. It discloses the use of superheated steam to preheat the heavy feed inside or outside the pyrolysis furnace to evaporate 50% of the heavy feed preheat and remove the residue (separate). The vaporized hydrocarbons (mostly -6-200909572 containing light volatile hydrocarbons) are cracked. U.S. Patent No. 5,1,90, 634, the disclosure of which is incorporated herein by reference in its entirety in its entirety in the the the the the the the the the the The hydrogen present in the convection section inhibits the polymerization of the hydrocarbons, thereby inhibiting coke formation. U.S. Pat. This preheated feed is then mixed with a predetermined amount of steam (diluted steam) and then added to a vapor-liquid separator to separate from the separator and remove the low proportions of volatile components and coke precursors in liquid form in the desired proportions. The separated vapor from the vapor-liquid separator is returned to the pyrolysis furnace for heating and cracking. U.S. Patent No. 6,632, 351, the disclosure of which is incorporated herein by reference in its entirety in its entirety, the disclosure of the entire disclosure of the disclosure of the entire disclosure of a first stage preheater in the convection zone, wherein the crude oil or crude oil portion containing the bitumen feed is heated in the first stage preheater to an outlet temperature of at least 37.5 ° C to produce a hot vapor-liquid mixture, Extracting the vapor-liquid mixture from the first stage preheater to a vapor-liquid separator, separating and removing gas from the liquid of the vapor-liquid separator and supplying the removed gas to the first portion provided in the convection zone The second preheater 'further heats the temperature of the gas to a temperature higher than the temperature of the gas exiting the vapor-liquid separator, adds the preheated gas to the radiation zone of the pyrolysis furnace' and pyrolyzes the gas into olefins and related by-products A method for increasing the non-volatiles removal efficiency of a flash tank of a steam cracking system is disclosed in U.S. Patent No. 7,097,75, incorporated herein by reference. The flow of the convection section is converted from a mist flow to an annular flow prior to entering the flash tank to increase removal efficiency. Converting the gas stream from the mist flow to the annular flow system first passes the gas stream through at least one expander and then to a different degree of curvature and forces the flow to change direction at least once. The flow of air from a mist to a ring helps to unite the fine droplets and thereby increase the efficiency of removing them from the vapor phase. U.S. Patent No. 7,138, the disclosure of which is incorporated herein by reference in its entirety, the disclosure the disclosure the disclosure the disclosure the disclosure the disclosure the disclosure the disclosure of The hydrocarbon feed is combined with a fluid and/or a main dilution vapor stream to form a mixture, flashing the mixture to form a vapor phase and a liquid phase, and operating parameters according to at least one selected program (eg, flash before entering the flash tank) The steaming temperature) changes the amount of fluid and/or primary dilution steam stream that is mixed with the hydrocarbon feed. U.S. Patent No. 11/068,615, filed on Jan. 28, 2005, the disclosure of which is incorporated herein by reference in its entirety, the disclosure of the entire disclosure of the disclosure of the disclosure of the disclosure of the disclosure of Forming a stream of the mixture that is flashed to form a vapor phase and a liquid phase, followed by cracking the vapor phase to provide an olefin, and cooling the product effluent in a transfer line exchanger, wherein the amount of fluid mixed with the feed is The operating parameters are varied depending on the selected program (e.g., flashing the mixture stream, i.e., the temperature of the mixture stream). U.S. Patent Application Serial No. 1/851,434, -8-2009, 095, filed on May 21, 2004, the disclosure of which is hereby incorporated by reference in its entirety in its entirety in its entirety in , 474, herein incorporated by reference, which is incorporated herein by reference, for the disclosure of the utility of the disclosure of the disclosure of the disclosure of the disclosure of the disclosure of the entire disclosure of the disclosure of the disclosure of the disclosure of the disclosure of A ring distributor for recirculating quenching oil, an anti-vortex baffle and a hob. Therefore, steam cracking hydrocarbon feeds with a small amount of coke formation require a novel and energy efficient process. The inventors have unexpectedly discovered that coke formation in the first preheating zone of the first preheating zone can be ignored when the feed is fed at an inlet linear velocity below the threshold enthalpy and the feedstock is preheated to a temperature below the threshold enthalpy. . Again, only at least 1 weight. /. The hydrocarbon feed exits the first preheating zone of the liquid phase, and coke formation in the first preheat zone is minimized. The disclosure thus provides for the treatment of hydrocarbon feedstocks by optimizing the linear velocity of the feed entering the preheating section of the steam cracking furnace with a minimum of coke formation in the preheating zone and a feed low pressure drop through the convection section. Steam cracking method. SUMMARY OF THE INVENTION In some embodiments, the present disclosure provides a method for treating a hydrocarbon feed comprising: (a) feeding the hydrocarbon at a linear velocity equal to or less than 0. 9 m/s. a first preheating zone fed to the convection section of the steam cracking furnace; (b) preheating the hydrocarbon feed in the first preheating zone to evaporate less than 99 mils. /. Hydrocarbon feed to form a vapor-liquid mixture; (〇 separating at least a portion of the vapor-liquid mixture to form a vapor portion and a liquid portion; and -9 - 200909572 (d) supplying at least a portion of the vapor portion to the steam Cracking Furnace 0 According to a specific example, the convection section comprises a plurality of heat exchange tubes and the hydrocarbon feed flows into the tubes. In a preferred embodiment, the hydrocarbon feed is between 0_05 and 0. The range of 85 m/s is preferably from 0·1 to 〇·8 m/s' and more preferably 0. 1 to 0. 75 m/s, supplied to the first preheating zone at linear velocity. In a preferred embodiment of the present disclosure, the first preheating zone includes a first preheating section and a second preheating section, wherein the hydrocarbon feed is between 790 and 1 8 2 5 k P a - a (absolute kilopascal) range of pressure, preferably in the range of 690 to 1450 kPa-a, more preferably in the range of 790 to 1400 kPa-a, more preferably in the range of 790 to 1200 kPa-a, and optimal Supplying to the first preheating zone at a temperature in the range of 790 to 1100 kPa-a and 25 to 250 °C to form the first preheating zone at a temperature ranging from about 1 Torr to 3 50 °C Preheating the hydrocarbon product, and then at least a portion of the preheated hydrocarbon product is supplied to the second preheating section along with the first dilution stream to form a discharge at a temperature ranging from 3 5 5 to 500 ° C The vapor-liquid mixture of the first preheating section and comprises at least 1% by weight of the liquid phase based on the total weight of the hydrocarbons in the vapor-liquid mixture. In some aspects, the hydrocarbon feed comprises steam cracked gas oil and residue, gas oil, coker naphtha, steam cracked naphtha, catalytically cracked naphtha, hydrocracked product Recombinant, raffinate recombination, virgin naphtha, crude oil, atmospheric pressure tube still bottom (atmospheric -10- 200909572 pipestill bottom), vacuum tube retort including bottom material, vacuum Gas oil, heavy gas oil, light oil contaminated with crude oil, atmospheric heavy oil, heavy residual oil 'C" residual oil mixture, light oil/residual oil mixture, Fischer-Tropsch liquid, Fischer-Tropsch gas One or more of Fischer-Tropsch, distillate and low-sulfur slag. In one embodiment, from 10 to 99_99% by weight of the hydrocarbon feed boils below 590 °C as measured according to ASTM D-2887. In another embodiment, the hydrocarbon feedstock is boiled at a ratio of from 10 to 95 percent below 5 90 ° C as measured according to ASTM D-2 8 87. In one embodiment, the present disclosure also provides a method of cracking a hydrocarbon feed to a light olefin in a steam cracking furnace having a radiant section combustor and a convection section, the convection section comprising the first set, the second set And a third set of heat exchange tubes, the method comprising: (a) a pressure in the range of 790 to 1825 kP aa, preferably in the range of 790 to 1450 kPa-a, more preferably in the range of 790 to 1400 kPa-a, and more preferably Feeding the hydrocarbon feed in a liquid phase of at least 99% by weight in the range of 790 to 1 200 kPa-a, and preferably in the range of 790 to 1100 kPa-a, and at a temperature in the range of 25 to 250 °C The first set of heat exchange tubes provided in the convection section, and the linear velocity is 〇.  a range of 1 to m·9 m/s; (b) preheating the hydrocarbon feed to form a preheated hydrocarbon product having a temperature below 35 °C; (c) supplying the pre-mixed stream At least a portion of the thermal hydrocarbon product to the second set of heat exchange tubes to evaporate at least a portion of the hydrocarbon feed to form a temperature having a temperature in the range of 350 to 500 ° C and comprising total hydrocarbons in the vapor-liquid mixture And at least a portion of the vapor-liquid mixture to form a vapor portion and a liquid portion; and (e) a step (() d) supplying at least a portion of the vapor portion to the third set of heat exchange tubes and further to the radiant section of the steam cracking furnace to form a product comprising light olefins, wherein the hydrocarbon feed comprises steam cracking gas and residual oil , gas oil, coking gasoline, steam cracking crude gasoline, catalytic cracking crude gasoline, hydrocracking products, recombination, raffinate recombination, distillate, straight-run light oil, crude oil, bottom of atmospheric pressure tube still The truth of the object, including the bottom Tube distillation tank flow, vacuum gas oil, heavy gas oil, crude oil contaminated light oil, atmospheric heavy oil, heavy residual oil, C4/residual oil mixture, light oil residual oil mixture and low sulfur wax residue One or more. In one embodiment, the vapor-liquid mixture has a temperature in the range of 400 to 500 ° C and comprises at least 2% by weight liquid based on the total weight of the hydrocarbons in the vapor-liquid mixture and wherein the hydrocarbon feed is 50 to 99. 99% by weight boiled below 590 °C as measured according to ASTM D-2887. In other embodiments, the vapor-liquid mixture has a temperature in the range of 425 to 500 ° C and comprises at least 3% by weight liquid based on the total weight of the hydrocarbons in the vapor-liquid mixture and wherein the hydrocarbon feedstock is 4 0 to 9 9. 9 9 wt% boils at a temperature lower than 5 90 ° C measured according to ASTM D-2 8 8 7 . In still other embodiments, the vapor-liquid mixture has a temperature in the range of 4 3 5 to 50 (TC range and comprises at least 4% by weight liquid based on the total weight of the hydrocarbons in the vapor-liquid mixture and wherein the hydrocarbon Feeding 30 to 99. 99% by weight is boiling at 5 90 ° C as measured according to ASTM D-28 87 below -12-200909572. In still other embodiments, the vapor-liquid mixture has a temperature in the range of 450 to 5 Torr (TC range and comprises at least 5% by weight liquid based on the total weight of the hydrocarbons in the vapor-liquid mixture and wherein the hydrocarbon feedstock 1〇 to 99. 99% by weight boils at a temperature lower than 5 90 °C measured according to ASTM D-2 8 8 7. There is now provided a device suitable for the steam cracking of a hydrocarbon feed to light olefins wherein the hydrocarbon feed is from 10 to 99. 99% by weight boiling below 590 ° C as measured according to ASTM D-28 87, the apparatus comprising: (a) a steam cracking furnace comprising a radiant section burner adapted to provide radiant heat and having a first set, a second The convection segment j (b ) of the group and the third group of heat exchange tubes is at 0. a linear velocity of 1 to 〇· 9 m / s to supply the hydrocarbon feed to the first set of heat exchange tubes (means); (c) maintaining the hydrocarbon feed below 305 °C a mechanism for discharging the first set of heat exchange tubes at a temperature; (d) simultaneously supplying a first dilution stream with at least a portion of the preheated hydrocarbon product from (c) to a hydrocarbon suitable for evaporation of less than 99% by weight a second set of heat exchange tubes to form a vapor-liquid mixture; (e) maintaining the vapor-liquid mixture at a temperature of 350 to 5 Torr (the temperature at which the second set of heat exchange tubes is discharged; (f a container adapted to separate at least a portion of the vapor-liquid mixture from step (e) to form a vapor portion and a liquid portion; and (g) to supply at least a portion of the vapor portion from step (f) to the third group Mechanism for heat exchange tubes. -13- 200909572 [Embodiment] The present disclosure relates to a method for heating and steam cracking a hydrocarbon feed to produce light olefins, such as ethylene and/or propylene. Typical products of steam cracking furnaces Including, but not limited to, ethylene, propylene, butylene, Diene, benzene, hydrogen, methane and other related olefins, alkanes and aromatic products. Ethylene as the main product 'often in the range of 15 to 30% by weight, based on the weight and composition of the evaporated feed. The method comprises preheating a hydrocarbon, mixing the preheated hydrocarbon with a dilute stream comprising at least one of steam, water, N2, H2, and a hydrocarbon to form a mixture, further preheating the mixture to form a vapor-liquid mixture Separating at least a portion of the vapor-liquid mixture in the vessel to form a vapor portion and a liquid portion, and supplying at least a portion of the vapor portion to the steam cracking furnace for further heating and cracking. Unless otherwise indicated in this disclosure, otherwise Percentages, parts, ratios, etc. are by weight. References to compounds or ingredients include the compound or ingredient itself' and combinations with other compounds or ingredients, such as mixtures of compounds. Further, when used, in concentration or in other amounts Or when the parameters are provided in the form of a preferred upper limit and a preferred lower limit, the salt is understood to be unambiguously disclosed. A preferred range of preferred upper limits 较佳 and preferred lower limits 而不 regardless of whether the ranges are disclosed separately. For this purpose, "low volatility components", sometimes referred to as non-volatile components or residues, are A hydrocarbon feed portion having a nominal boiling point above 59 (TC) as measured according to ASTM D-28 87. This disclosure can contain hydrazine.  The hydrocarbon feed of from 1 to 90% by weight of the low volatility component is suitably carried out. For use in this-14-200909572, "Coke Precursor" is a hydrocarbon feed portion having a nominal boiling point above 7 60 ° C when measured according to ASTM D-28 8 7. This disclosure can contain The hydrocarbon feed of 1 to 90% by weight of the coke precursor is suitably carried out. The boiling point distribution of the hydrocarbon feed is measured by gas chromatography distillation (GCD) according to ASTM D-28 8 7. The phrase "substantially liquid phase" at this point means at least 99% by weight, preferably at least 9 9. 5重量%, more preferably at least 9 9 · 9 wt%, and most preferably at least 99. 99% by weight liquid phase. For example, a stream in a substantially liquid phase means at least 99% by weight of the stream, preferably at least 9 9. 5 wt%, more preferably at least 9 9 -9 wt% ' and optimally at least 9 9. 99% by weight is in the liquid phase. The phrase "vapor fraction" used herein at this time means primarily, preferably at least 75 wt%, more preferably at least 9 wt%, and more preferably at least 95 wt% of the vapor phase. The phrase "liquid portion" at this time means that the portion is mainly 'preferably at least 7.5 wt%', more preferably at least 90 wt%, and more preferably at least 95 wt% is in the liquid phase. At this point the phrase "mainly, or" primarily, means more than 5% by weight. For example, 'diluted stream mainly comprising steam means that the dilution stream contains more than 5% by weight of steam. Hydrocarbon feed. The feed may contain at least a portion, such as at 0. 0 1 to 90 0 weight 1 to 9 〇 by weight, or 5 to 90% by weight of low volatility components and coke precursors. This feed may include, by way of non-limiting example, steam cracking gas and residual %, gas, heating oil, jet fuel, diesel-15-200909572 'kerosene, gasoline, coking gasoline, steam cracking coarse Gasoline, catalytic cracking of crude gasoline, hydrocracking products, recombinants, raffinate recombination, Fischei-Tropsch liquid, Fischer-Tropsch gas, Fischer-Tropsch wax, natural gasoline, distillate, straight run light Oil, atmospheric tube distillation still bottom, vacuum tube distillation tank including bottoms, wide boiling range light oil to gas oil concentrate, heavy non-stratrocolt hydrocarbon stream in refinery, vacuum gas oil, Heavy gas oil, light oil contaminated by crude oil, heavy oil at atmospheric pressure, heavy residual oil, C4/residual oil mixture, light oil/residual oil mixture, hydrocarbon gas/residual oil mixture, hydrogen/residual oil mixture, gas oil/ One or more of the residual oil mixture, crude oil, and low sulfur wax residue. The hydrocarbon feed may have a nominal boiling endpoint of at least 3 15 t, typically greater than 510 ° C 'often greater than 5 90 ° C, for example Greater than 76 (TC. Economically preferred feed is generally low sulfur wax residue 'often Heavy-duty oil, light oil contaminated with crude oil, different residue mixtures, and crude oil. Gas-to-liquid (GTL) technologies used to make medium distillates, such as SMDS, AGC-21, and SSPD, are shown for fuel replacement and higher prices. The great potential of the hydrazine product. The product of any Fischer-Tropsch gas-to-liquid process can be further processed, optionally hydrotreated, fractionated to become a Fischer-Tropsch liquid (also known as Fischer-Tropsch light oil), Fischer-Tropsch gas oil (also It is called Fischer-Tropsch gas and Fischer-Tropsch wax. Fischer-Tropsch light oil, Fischer-Tropsch gas oil and Fischer-Tropsch wax produced by these GTL processes are attractive for steam cracking applications due to their high concentration of normal paraffin components. The high alkane content of the Fischer-Tropsch liquid and Fischer-Tropsch gas allows it to be cracked under the high severity that is not commonly found in conventional feeds. In some specific examples, the method disclosed in the present disclosure has been found to be useful for the use of -16-200909572 A feed comprising at least one weight of a charge liquid, a Fischer-Tropsch gas, a Fischer-Tropsch wax, a crude oil, a crude oil fraction, etc. In other specific examples, the method disclosed in the present disclosure is found to be useful for processing at least 1% by weight A feed of at least one of a Fischer-Tropsch liquid residue, a Fischer-Tropsch gas residue, a Fischer-Tropsch liquid fraction, and a Fischer-Tropsch gas column. Process Description The present disclosure is described below with reference to Figure 1, which is disclosed in the present disclosure. An illustration of one of many specific examples of content. Any number and type of processing steps may be included between the various processing steps described in this disclosure or between the origin and destination described within a processing step. The cracking furnace can be any type of conventional olefin steam cracking furnace for producing low molecular weight hydrocarbon burning, especially including a tubular steam cracking furnace. The tubes in the convection section of the steam cracking furnace can be arranged side by side into a group of heat exchange tubes, or The tubes may be arranged as a single or multiple channels of feed through the convection zone. At the inlet the feed can be dispensed to a plurality of single channel tubes or to a single channel tube. All feeds flow from the tube inlet to the outlet through the single channel tube, and preferably through the entire convection zone. Preferably, the first preheating zone comprises at least one single channel group heat exchange tube disposed in the convection zone of the steam cracking furnace. In a preferred embodiment, the convection zone comprises less than 20 channel tubes divided into two or more groups. The hydrocarbon feed flows through them. In each group, the tubes may be arranged in a spiral or curved arrangement in a row, and each group may have several rows of tubes. The number of channels disposed in the convection zone of the steam cracking furnace useful in this disclosure -17 - 200909572 is in the range of 1 to 20. In some, the number of channels that are configured to be exchanged in the convection zone of a steam cracker useful in this disclosure is 2, 4, 6, 8, 10, 12, 14, and 1 20 . In other embodiments, the number of channels disposed in the heat exchange tubes useful in the convection zone of the present invention is 1, 3, 5 11, 13, 15, 17, or 19. In some embodiments, the steam useful in this disclosure, as exemplified in FIG. 1, includes convection section 3 and radiant section 13 segment 13 including radiant combustion vapor cracking that provides radiant heat and hot flue gas 12 The convection section 3 of the furnace 1 comprises a first preheating zone 5 and a second. The first preheating zone 5 includes a first preheating section 7 and a second preheating first preheating zone and a second preheating zone comprising a plurality of sets of heat exchange tubes. In the example, the first preheating section 7 comprises a first set of heat exchange tubes 15 comprising a second set of heat exchange tubes 17, and a second set of heat exchange tubes 19 in the second preheating zone. The steam cracking furnace 1 also contains: ξ It is understood that the steam cracking furnace 1 can include any number of processing equipment, valves, injection points, meters, meters, and control devices. Will contain at least a part, such as 〇.  〇1 to 90% by weight, 1% by weight or 5 to 90% by weight of the low volatility component and the coke precursor material 31 are supplied to the first first preheating section 7 of the convection section 3 of the steam cracking furnace 1, and Preheat it in it. The hydrocarbon feed is familiar to those skilled in the art in any manner. In any event, it is preferred that the hot flue gas 12 containing the radiant section 13 of the furnace is in indirect contact with the hydrocarbon feed of the seventh. This can be done, in a non-limiting manner, in the specific example of the heat transfer 6, 18 or steam cracking, 7, 9, cracking furnace 1 i. The radiator. The steam preheating zone 1 1 ; segment 9. The one specific to the second pre-U is included. Salty, such as, pump. Up to 90 weights of hydrocarbons into the preheating zone 5 can be heated by the heating pack a preheating section to feed the hydrocarbons-18-200909572 through the first set of heat exchange tubes 1 located in the first preheating section 7 And finished. Maintain the pressure of the hydrocarbon feed to the inlet of the first preheat section of the convection zone to ensure that the pressure is less than! 82 5 kPa-a' is preferably less than 1 480 kPa-a, more preferably less than 1 400 kPa-a ' and most preferably less than 1 200 kPa-a. In some embodiments, maintaining the pressure of the hydrocarbon feed to the inlet of the first preheating section of the convection zone to ensure a pressure in the range of 790 to 1 825 kPa-a' more preferably at 790 to 1480 kPa-a More preferably at 790 to 1450 kPa-a' and more preferably at 790 to 140 G kPa-a, still more preferably at 790 to 1200 kPa-a, and optimally at 790 to 00 kPa-a, and at a temperature of 25 To 250. a range of (:), often controlling the feed rate of the hydrocarbon feed to the inlet of the first preheating section of the convection zone at 50 to 20 °C °C to maintain the inlet linear velocity of the hydrocarbon feedstock less than 1 .  1 m/s ' is preferably less than 1 m/s ‘ more preferably less than 0. 9, and more preferably 0. 05 to 〇·9 m/s ‘and even more preferably from 0·1 to 〇·9 m/s, and even more preferably 0. 2 to 0. 8 m/s. In a preferred embodiment of the disclosure, the inlet linear velocity of the hydrocarbon feed is less than _ _ 9 m / s. In other specific examples, the inlet linear velocity of the hydrocarbon feed is at 0. 0 5 to 0. A range of 9 m/s. The following inlet linear velocity of the hydrocarbon feed is a useful lower limit of the inlet linear velocity: 〇 · 0 5, 〇.  1, 0_2, 0_3, 0. 4, 0. 5, hehe. 6, 〇·7 and 〇. 8. The following inlet linear velocity of the hydrocarbon feed is a useful inlet linear velocity upper limit: 0 · 9, 0. 8, 0. 7, 0. 6, 0. 5, 0. 4, 0. 3, 0·2 and 0·1. The inlet linear velocity of the tobacco feed desirably falls within the range between any of the above lower limits and any of the above upper limits, as long as the lower limit is less than or equal to the upper limit. The hydrocarbon feed enters -19-200909572. The linear velocity of the mouth can exist in the range of 0 · 0 5 to 1 in a specific example, or 〇. ! to 0_5, or 〇. 4 to 〇 9, or 〇 5 to 〇 85, or 〇_2 to 0. 5, or in another specific example 〇·5 to 〇. 6. We have unexpectedly found that the coke formation in the first preheating zone of the first preheating zone is negligible. Further, as long as at least 1% by weight of the hydrocarbon feed is discharged to the first preheating zone in a liquid phase, the coke formation of the first preheating zone will be minimized. The inlet linear velocity of the hydrocarbon feed can thus be selected to maintain optimum heat transfer efficiency and low pressure drop. The proper linear velocity of a particular feed will simultaneously improve heat transfer efficiency and reduce the pressure drop downstream of the first preheat section. The preheated hydrocarbon feed 33 exits the first preheat section 7 and is then mixed with the fluid 35 as needed. This fluid can be a liquid hydrocarbon, water, steam or a mixture thereof. A preferred fluid is water. The temperature of the fluid can be below, equal to, or above the temperature of the preheat feed. The mixing of the preheated hydrocarbon feed with the fluid can be carried out inside or outside the steam cracking furnace 1, but is preferably carried out inside the furnace. This mixing can be accomplished using any mixing device known in the art. The preheating feed exits the first set of heat exchange tubes 15 at a temperature in the range of about 100 to 35 volts, preferably in the range of 丨5 〇 to 3 2 5 t, more preferably 160 to 3 〇. Hey. The range of 〇 is in the range of 丨7〇 to 3〇〇 °C. In a preferred embodiment, the preheated hydrocarbon feed 3 3 exits the first preheat section 7 in a substantial liquid phase. In a preferred embodiment in accordance with the disclosure, a first dilution stream 37 is mixed with the preheated hydrocarbon feed. In some embodiments, the first diluent stream comprises at least one of steam, water, nitrogen, hydrogen, and hydrocarbons. Preferably -20- 200909572 the first dilution stream comprises at least one of steam and water. The first dilution stream is preferably injected into the preheated hydrocarbon before the resulting steam mixture enters the first preheating zone 5 of the convection section 3 of the steam cracking furnace 1 and the second preheating section 9 is additionally heated by the radiant section flue gas. material. The first dilution stream can have a temperature above, below, or the same as the preheated hydrocarbon feed, but is preferably greater than the temperature of the preheated hydrocarbon feed and is used to locally vaporize the preheated hydrocarbon feed. . Alternatively, the first dilution stream is overheated prior to injecting the preheated hydrocarbon feed. The preheated hydrocarbon feed, the first dilution stream, and optionally the mixture of fluids are further heated in a second preheating zone 9 of the convection section 3 of the steam cracking furnace 1 to produce a vapor-liquid mixture. This heating may, in a non-limiting manner, pass the feed mixture through a second set of heat exchange tubes 17 located in the second preheating zone 9 and thus be heated by the hot flue gas of the radiant section of the furnace. carry out. The thus heated mixture 39 exits the convection section as a stream of the mixture. The vapor-liquid mixture stream 39 is temperature-limited by the most recovered/evaporated volatiles in the feed while avoiding coking or the vessel from the vessel. Coking the mixture to the tubes and vessels of the furnace. The choice of temperature for the vapor-liquid stream 39 is also determined by the composition of the feed material. When the feed contains a relatively large amount of lighter hydrocarbons, the temperature of the mixture stream 39 can be lower. When the feed contains a relatively large amount of low volatility hydrocarbons, the temperature of the vapor-liquid mixed stream 39 should be relatively high. The application of various different feed materials can be found by careful selection of the mixture stream temperature. Frequently, the temperature of the vapor-liquid mixture stream 39 is set and controlled from -21 to 200909572 between 3 1 5 and 5 10 ° C, preferably between 3 70 and 490 ° C, more preferably 400. Between 480 ° C and preferably between 430 and 475 ° C. These enthalpies will vary with the boiling curve and the concentrated volatiles in the feed. The amount of liquid phase in the vapor-liquid mixture stream 39 is calculated as the total weight of hydrocarbons in the vapor-liquid mixture stream 39. The vapor-liquid mixture 39 comprises at least 1% by weight liquid. The amount of liquid phase of the vapor-liquid mixture stream 39 is limited by the most recovered/evaporated volatiles in the feed while avoiding coking in the furnace tubes or coking from the vessel to transport the mixture to the tubes and vessels of the furnace. The choice of temperature of the vapor-liquid stream 39 is also determined by the composition of the feed material. When the feed contains a relatively large amount of lighter hydrocarbons, the liquid content of the mixture stream 39 can be set lower. When the feed contains a relatively large amount of low volatility hydrocarbons, the liquid content of the vapor-liquid mixture stream 39 should be set higher. By carefully selecting the liquid content of the mixture stream, this disclosure can find application of a variety of different feed materials. In some embodiments, the vapor-liquid mixture stream has a liquid content ranging from 1% to 99% by weight. In other embodiments, the liquid content of the vapor-liquid mixture stream is in the range of from 2% by weight to 60% by weight. In still other embodiments, the liquid content of the vapor-liquid mixture stream is in the range of from 5% by weight to 30% by weight. The following liquid content of the vapor-liquid mixture stream is a useful lower liquid content: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12 and 15. The liquid content of the following vapor-liquid mixture stream is the upper limit of useful liquid content: 99, 90, 80, 70, 60, 50, 40, 30, 25, 20 and 15. The liquid content of the vapor-liquid mixed stream desirably falls within the range between any of the above lower limits and any of the above upper limits of -22-200909572 as long as the lower limit is less than or equal to the upper limit. In a preferred embodiment, the dilution stream 41 comprising at least one of steam, water, nitrogen, _ Λ ^ ® and hydrocarbons is preferably primarily steam and/or water, in a group of heat exchange tubes. The heating in 43 is carried out to a desired temperature, preferably overheating. The resulting dilution stream 45 is withdrawn from the convection section 3 and, if necessary, divided into a second dilution stream 47, which is preceded by the vessel 53 and a vapor-liquid mixture withdrawn from the second preheating section 9 Mixing, a 7-minute dilution stream 49, the bypass dilution stream 49 bypasses the vessel and is exchanged for mixing with the vapor portion prior to cracking of the vapor portion of the vessel in the radiant section of the furnace. In one embodiment, the disclosure can operate as all of the dilution stream 45 of the flashed second dilution stream 47 without the bypass stream 49. Alternatively, this disclosure can operate with all of the dilution streams 45 leading to the side splits 49 without the table one dilution stream 47. In a preferred embodiment of the disclosure, the ratio of the second dilution stream 47 to the side stream 49 should preferably be 1: 2 〇 to 20.  1' and most preferably 1: 2 to 2: 1. The second dilution stream 47 is mixed with the vapor-liquid mixture stream 45 prior to flashing in the vessel 53 to form a flash stream 51. Preferably, the first dilution stream is overheated in the overheating section 43 of the furnace convection prior to separation and mixing of the vapor-liquid mixture. The addition of the flash stream 47 to the vapor-liquid mixture stream 39 will ensure that almost all of the volatile components of the mixture evaporate prior to entering the vessel 53. The vapor-liquid mixture and the second dilution stream mixture 5 1 are then added to a vessel 5 3 for separation into two parts: a vapor portion mainly comprising a volatile hydrocarbon and a liquid portion mainly comprising a low-volatile hydrocarbon. The vapor -23- 200909572 portion is preferably removed from the vessel 53 in a manner that the head vapor stream 5 5 . ^ / & 3, the gas stream 5 5 , preferably, is supplied back to the convection & / ft 2 preheating zone 1 of the steam cracking furnace 1 for selective heating and further transmission through the communication pipe 59 1 / ' # &gt From the radiant section of the steam cracking furnace for cracking. The separated liquid portion is removed with a square % container 53 of the bottom stream 57. Flashing is carried out in at least one container. Preferably, the flash 1^c rate is 14 〇〇 without a one-stage procedure for reflux. The container 53 is normally operated at a pressure of kPa-a between 27 5 # -3⁄4 skirts and its temperature is hoisted or slightly lower than the temperature of the mixture 51 before entering the container 53. Frequently, the container 53 has a force of 275 to 1400 kPa-a and a temperature of 310 to 510 °C. Preferably, the container 53 has a pressure of 600 to 1100 kPa-a and a temperature of 370 to 490 °C. More preferably, the container 53 has a pressure of 700 to 1000 kPa-a and a temperature of 4 to 480 °C. Most preferably, the container 53 has a pressure of 700 to 760 kPa-a and a temperature of 430 to 48 〇〇c. Depending on the temperature of the flash stream, 50 to 95% of the mixture entering the vessel 53 is often evaporated to the upper portion of the vessel 53' preferably from 60 to 95%, more preferably from 65 to 95%, and most preferably 7 0 to 9 5 %. In the vessel 53, the vapor portion 55 typically contains less than 400 ppm of coke precursor' preferably less than 1 〇〇 ppm, more preferably less than 8 〇 ppm ' and most preferably less than 5 〇 ppm. The vapor portion is enriched with volatile hydrocarbons (e.g., '5 5 to 70 vol. / (> ) and steam (e.g., 3 Torr to 45 vol.). The boiling end of the vapor phase is normally below 7 6 〇〇c. The vapor partial stream 5 5 that is continuously removed from the vessel 5 3 is preferably a flue gas by the convection section of the furnace! 2 in the convection section below the steam cracking furnace -24 -24- 200909572 Excessively heated to, for example, a temperature in the range of 4 30 to 65 ° C. The vapor portion is then lysed by the radiant section of the steam cracking furnace. The vapor partial stream removed from the vessel 53 can be optionally used. Mixing with the bypass steam stream 49 prior to the addition of the lower convection section 1 1 of the furnace. Apparatus specific examples now provide a apparatus suitable for steam cracking a hydrocarbon feed to light olefins comprising: (a) a steam cracking furnace, It comprises a radiant section burner adapted to provide radiant heat and hot flue gas and a convection section comprising the first, second and third sets of heat exchange tubes; (b) at 0.  1 to 0. a linear velocity in the range of 9 m/s to supply the hydrocarbon feed to the first set of heat exchange tubes (me an s); (〇) maintaining the hydrocarbon feed at a temperature below 305 °C a mechanism for discharging the first set of heat exchange tubes; (d) simultaneously supplying a first dilution stream with at least a portion of the preheated hydrocarbon product from (c) to a hydrocarbon feed suitable for evaporation of less than 99% by weight a mechanism for the vapor-liquid mixture; (e) a mechanism for maintaining the vapor-liquid mixture at a temperature ranging from 350 to 500 ° C for discharging the second group of heat exchange tubes; (f) for separating the vapor from step (e) a container forming at least a portion of the liquid mixture to form a vapor portion and a liquid portion; and (g) supplying at least a portion of the vapor portion from step (f) to the third group of heat exchange tubes and further to the radiation of the steam cracking furnace Duan Zhi-25- 200909572 Organization. The means for feeding in steps (b) and (g) may be any pumping mechanism or a conduit for conveying material. The mechanism used in step (c) 2 can be any conventional mechanism for controlling temperature, pressure, flow rate control, and/or control valves. A mechanism for maintaining the vaporized J mixture from exiting the second set of tubes at a temperature in the range of 350 to 500 °C is to inject a fluid, such as water, from the preheated hydrocarbon product prior to (d). The vessel in step (f) may be a vapor-liquid mixture capable of separating (e) to form a vapor portion and a liquid portion of a type of vessel, tank or tank. In one embodiment, the container of the step is a flash tank. In another embodiment of the disclosure, the vessel in (f) is one of a column, a tube, a distillation column, a flash column, and a tank. EXAMPLES The following examples illustrate some specific examples of the disclosure and are intended to limit the scope of the disclosure. Comparative Examples 1, 2, 3, and 4 Examples 1, 2, 3, and 4 are prophetic examples, and they use the model to build Simulated Sciences Provision 6_0 and 7. The 1st version is used to simulate the p r 〇 V i s i ο η 7 · 1 version for hydraulic simulation. Example 2 A and 4A are the results obtained for the factory facility. The following feeds, A, B 1, C and D1 were used for the feeds B2 and D2 shown in Table 1 and tested in Examples 2A and 4A. The material is characterized by the use of 1) the liquid volume percentage boiling point of the conventional pump (e), the feedback R-liquid heat exchange (c), the step (f), the step is at least not a trial and implementation program, wherein Example simulation. -26-200909572 ASTM and/or 2 Chromatography for these twist lines, Figure 86 of the line defined by the curve (Standard test method for distillation of petroleum products under normal pressure); ASTM D 2 8 for weight percent boiling point curves 8 7 (Standard test method for steam distribution by partial boiling point of petroleum) The method is to compare the temperature of the laboratory technology or TBP with the mass percentage distillation at 1 5 / 5 (15 theoretical plates, 5: 1 reflux ratio) song. All molecular weights 値 are weight average molecular weights. -27- 200909572 Table 1 Feed: A B1 B2 C D1 D2 Specific Gravity (g/ml) 0. 8769 0. 821 0. 8302 0. 8566 0. 9082 0. 8787 D86IBP (0. 5 vol%), (.〇63 62 122 236 309 277 D86 5 vol%, (°C) 143 315 D86 10 vol%, (.〇131 99 172 290 362 346 D86 20 vol%, (.〇219 377 D86 30 vol%, (°〇225 159 257 319 403 398 D86 40 volume 288 413 D86 50 vol%, (°C) 307 240 318 342 434 431 D86 60 ffi*%, (°C) 347 455 D86 7〇mm. %,CC) 400 316 375 364 466 490 D86 80 vol%, (°C) 405 553 D86 90 vol%, (.〇535 472 456 394 508 711 D86 95 vol%, (.〇515 815 D86EP (99_5 vol% ), (.〇662 626 643 440 546 871 Molecular weight, 210 163 250 293 422 479 TBP(15/5) IBP (0_5 wt%), (°C) -1 -11 79 196 251 208 TBP(15/5) 5 wt%, (°〇79 35 119 232 335 307 TBP(15/5) 10% by weight, (°C) 119 73 154 287 360 346 TBP( 15/5) 20% by weight, (.〇186 118 219 316 396 388 TBP(15/5)30% by weight, (°C) 238 157 264 324 421 416 TBP(15/5)40% by weight, (°C) 285 221 301 333 442 437 TBP(15/5)50 Weight %,(°〇333 251 336 350 462 457 TBP( 15/5) 60% by weight, (°C) 384 289 368 366 482 485 TBP( 15/5)70 Weight 0/〇, (°C) 438 350 401 378 503 534 TBP(15/5) 80% by weight, (.〇500 425 438 389 529 626 TBP( 15/5) 90% by weight, (°〇606 535 503 413 558 847 TBP( 15/5) 95% by weight , (°C) 685 630 590 440 580 950 TBP(15/5)EP (99. 5 wt%, (°C) 799 777 959 465 621 1032 Viscosity @49°C, 896kPa-a, (CP) 4. 1564 1. 708 3. 21 5. 0996 37. 479 42. 21 -28- 200909572 Comparative Example 1 Feed A, crude oil feed, having the properties listed in Table 1 above, was used as the hydrocarbon feed of this example. At a temperature of 127 ° C, a pressure of 2413 kPa-a and 111. At a rate of 8 tons / hr, this has a specific gravity of 0. A crude oil feed A of 8 769 ml/g and an average molecular weight of 210 is supplied to the inlet of the first set of heat exchange tubes 15 of the convection section 3. The feed A, at this point, is all liquid and passes through a first set of heat exchange tubes 15 having eight rows of tubes. The feed a is supplied to the inlet of the first set of convection heat exchange tubes 15 at a linear velocity of 1 · 28 m / s. The feed A was heated to a temperature of 181 ° C and discharged in a total liquid phase at a pressure of 2393 kPa-a. The pressure drop across the first set of heat exchange tubes 15 of the convection section is about 2 1 k P a. The heated feed A exits the first set of heat exchange tubes 15 in a liquid phase and is mixed with steam having a flow rate of 30 tons/hr. After mixing with the steam, a portion of the hydrocarbon feed is vaporized to form a vapor-liquid mixture having a liquid phase of 71% by weight based on the total weight of the hydrocarbon feed and the vapor turbulent stream. The vapor-liquid mixture is subsequently supplied to a second set of heat exchange tubes 17 having a tube diameter of about 13% larger than the tube diameter of the first set of heat exchange tubes 15. The vapor-liquid mixture is supplied to the second set of heat exchange tubes 17 at a linear velocity of 12 m/s, wherein the vapor-liquid mixture is further heated to a temperature of 45 8 ° C, and at the temperature and about The set of heat exchange tubes 17 is discharged at a pressure of 952 kPa-a. At the outlet of the second set of heat exchange tubes 17, the weight percentage of liquid exiting the second set of heat exchange tubes 17 was then reduced to 1% by weight of the entire stream. The pressure drop across the second set of heat exchange tubes 17 of the convection section is about 1 448 kPa. The combined pressure drop across the first set of heat exchangers -29-200909572 and the second set of heat exchange tubes 17 across the convection section is 1 469 kPa. The vapor-liquid mixture exits the second set of heat exchange tubes 17 in the convection section of the steam cracking furnace at a linear velocity of about 35 m/s and is about 2. 7 tons/hr of steam was overheated to 482 °C at a pressure of 9.5 2 kPa-a. The resulting vapor-liquid mixture is at a temperature of 45 8 t and 811. The pressure of 7 kPa-a flows to the vapor-liquid separator 53 and has a liquid weight percentage of 7% by weight of the entire stream due to the addition of the excessive heating stream. Example 1 Feed A, crude oil feed, having the properties listed in Table 1 above, was used as the hydrocarbon feed of this example. At a temperature of 127 ° C, a pressure of 95 8 kPa-a and 111. At a rate of 8 tons / hr, this has a specific gravity of 0. A crude oil feed A of 8 7 6 9 ml/g and an average molecular weight of 210 is supplied to the inlet of the first set of heat exchange tubes 15 of the convection section 3. The feed A, at this point, is all liquid' passing through a first set of heat exchange tubes 15 having eight parallel tubes. The feed A is at 0. The inlet to the first set of convection heat exchange tubes 15 is supplied at a linear velocity of 5 5 m/s. The feed A was heated to a temperature of 1 81 ° C and discharged as a whole liquid at a pressure of 967 kPa-a. The pressure drop across the first set of heat exchange tubes 15 of the convection section is about -9 kP a (the negative pressure drop is partially due to gravity). The heated feed A discharges the first set of heat exchange tubes 15 in a liquid phase and has a flow rate of 3 0. 5 tons / h r at 1 1 4 2 k P a - a and 2 1 1 . (: under steam mixing. After mixing with steam, one portion of the hydrocarbon feed is vaporized to form having a total weight of hydrocarbon feed and vapor combined turbulence. A vapor-liquid mixture of 6 wt% liquid phase. This vapor-liquid mixture is subsequently supplied to a second set of heat -30-200909572 exchange tubes 17 . The vapor-liquid mixture is supplied to the second set of heat exchange tubes 17 at a linear velocity of 1 1 _ 9 m/s, wherein the vapor-liquid mixture is further heated to a temperature of 4 58 ° C, and The second set of heat exchange tubes 17 is discharged at a temperature of about 8 1 9 kP a- a. At the outlet of the second group of heat exchange tubes 17, the weight percentage of liquid discharged from the second group of heat exchange tubes 17 was then reduced to 10% by weight of the entire stream. The pressure drop across a group of heat exchange tubes 17 of the convection section is about 1 45 kPa. The combined pressure drop across the first set of heat exchange tubes 15 and the second set of heat exchange tubes 17 of the convection section is 136 kPa. The vapor-liquid mixture is about 34. At a linear velocity of 7 m/s, the second set of heat exchange tubes in the convection section of the steam cracking furnace is discharged and the flow rate is about 2. 7 tons/hr was overheated to 4,821: steam mixing at a pressure of 819 kPa-a. The resulting vapor-liquid mixture is at a temperature of 45 8 t and 811. The pressure of 7 kPa-a flows to the vapor-liquid separator 53 and has a liquid weight percentage of 7% by weight of the entire stream due to the addition of the excessive heating stream. Comparative Example 2 Feed B 1, a light crude oil feed having the properties listed in Table 1 above was used as the hydrocarbon feed of this example. At a temperature of 8 8 ° C, a pressure of 1 8 9 6 kPa-a and 93. At a rate of 4 tons / hr, this has a specific gravity of 0. A crude feed B 1 of 821 m 1 /g and an average molecular weight of 1 63 is supplied to the inlet of the first set of heat exchange tubes 15 of the convection section 3. The feed B1, at this point, is all liquid' passing through a first set of heat exchange tubes 15 having eight parallel tubes. The feed B 1 is at 1 . At the linear velocity of 2 3 m/s, the inlet to the first set of convection section heat -31 - 200909572 exchange tube 15 is supplied. The feed B 1 was heated to a temperature of 丨 44 ° C and discharged as a full liquid at a pressure of 1875 kPa-a. The pressure drop across the first set of heat exchange tubes 15 of the convection section is about 21 kPa. The heated feed B1 was discharged in the liquid phase from the first set of heat exchange tubes 15 and mixed with steam having a flow rate of 27 tons/hr. After mixing with the steam, a portion of the hydrocarbon feed is vaporized to form a vapor-liquid mixture having a liquid phase of 6.3 wt% based on the total weight of the hydrocarbon feed and vapor turbulent stream. The vapor-liquid mixture is subsequently supplied to a second set of heat exchange tubes 17 having a tube diameter of about 1 9 _ 4 % of the tube diameter of the first set of heat exchange tubes 15 . The vapor-liquid mixture is supplied to the second set of heat exchange tubes 17 at a linear velocity of 1 〇m / s, wherein the vapor-liquid mixture is further heated to a temperature of 446 ° C, and at the temperature and about The second set of heat exchange tubes 17 are discharged under a pressure of 8 5 5 kPa-a. The percentage by weight of the liquid exiting the second set of heat exchange tubes 17 at the outlet of the second set of heat exchange tubes 17 was then reduced to 5% by weight of the entire stream. The pressure drop across the second set of heat exchange tubes 17 of the convection section is about 1027 kPa. The combined pressure drop across the first set of heat exchange tubes 15 and the second set of heat exchange tubes 17 of the convection section is 1 048 kP a. The vapor-liquid mixture exits the second set of heat exchange tubes 17 in the convection section of the steam cracking furnace at a linear velocity of about 26 m/s and at a flow rate of about 5 · 5 tons / hr at 8 5 5 kPa - Under a pressure of a, the steam was overheated to 473 °C. The resulting vapor-liquid mixture was at 4 4 6 . (: temperature and 8 8 9. The pressure of 5 kPa-a flows to the vapor-liquid separator 53 and has a liquid weight percentage of 4% by weight of the entire stream due to the addition of the excessive heating stream. -32- 200909572 Example 2 Feed B 1 'Light crude oil feed having the properties listed in Table 1 above was used as the hydrocarbon feed of this example. At a temperature of 8 8 ° C, a pressure of 9 7 9 kPa-a and 93. This has a specific gravity at a rate of 4 tons / hr. A crude oil feed b 1 of 821 ml/g and an average molecular weight of 1 63 is supplied to the inlet of the first group of heat exchange tubes 15 of the convection section 3. The feed b1, at this point, is all liquid' passing through a first set of heat exchange tubes 15 having eight parallel tubes. The feed B 1 is at 0. The inlet to the first-stage convection section heat exchange tube 15 is supplied at a linear velocity of 49 tn/s. The feed B1 is heated to 144. The temperature of (: is discharged as a whole liquid at a pressure of 989 kPa-a. The pressure drop across the first heat exchange tubes 15 of the convection section is about -10 kPa (the negative pressure drop is partly due to gravity). The heated feed B 1 discharges the first set of heat exchange tubes 15 in a liquid phase and with a flow rate of 26. 6 tons / hr of steam at 1142 kPa-a and 211 °C. After mixing with the steam, one portion of the hydrocarbon feed is vaporized to form a vapor 1-liquid mixture having a liquid phase of 6.3 wt% of the total weight of the hydrocarbon feed and vapor turbulent stream. The vapor-liquid mixture is subsequently supplied to a second set of heat exchange tubes 17 having a tube diameter of about 44% greater than the tube diameter of the first set of heat exchange tubes 15. The vapor-liquid mixture is supplied to the second set of heat exchange tubes 17 at a linear velocity of 1 〇·5 m/s, wherein the vapor-liquid mixture is further heated to a temperature of 446 C and at the temperature and at about 896 The second set of hot parent exchange tubes 17 is discharged under the pressure of kPa-a. At the outlet of the second set of heat exchange tubes 17, the weight percentage of liquid exiting the second set of heat exchange tubes 17 is then reduced from -33 to 200909572 to 5% by weight of the entire stream. The pressure drop across the second set of heat exchange tubes 17 of the convection section is about 1 17 kPa. The combined pressure drop across the first set of heat exchange tubes 15 and the second set of heat exchange tubes 17 of the convection section is 107 kP a. The vapor-liquid mixture is at about 26. At a linear velocity of 4 m/s, the second set of heat exchange tubes in the convection section of the steam cracking furnace is discharged and the flow rate is about 5. 5 tons/hr was overheated to 473 t of steam mixing at a pressure of 896 kPa-a. The resulting vapor-liquid mixture is at a temperature of 44 6 ° C and 8 8 9. The pressure of 5 kPa-a flows to the vapor/liquid separator 53 and has a liquid weight percentage of 4% by weight of the entire flow due to the addition of the excessive heating flow.

Example 2A Feed B2' Light crude oil feed having the properties listed in Table 1 above was used as the hydrocarbon feed of this example. The light crude oil feed B2 having a specific gravity of 〇.83〇2 ml/g is supplied to the convection at a temperature of 1 15 ° C, a pressure of about 135 kPa-a, and a rate of 61.5 ton / hr. The inlet of the first set of heat exchange tubes 15 of section 3. The feed B2, at this point, is all liquid and passes through a first set of heat exchange tubes 15 having eight parallel tubes. The feed B2 is supplied to the inlet of the first set of convection heat exchange tubes 15 at a linear velocity of 0·36 m/s. The feed B 2 was heated in the first set of heat exchange tubes 15 of the convection section 3 and was evaluated at 96 weights. Discharged in the liquid phase. The heated feed B2 of the set of heat exchange tubes 15 is discharged at a flow rate of 11.6 ton / hr at 2999 kPa-a and 138. (: water and flow 2.4 tons / hr steam mixing at 1138 kPa-a and 19 PC. After mixing with water and steam, one part of the hydrocarbon feed is evaporated to form a hydrocarbon feed and steam - 34- 200909572 The total weight of the steam turbulent flow is estimated to be 77% by weight of the vapor-liquid mixture of the liquid phase. The vapor-liquid mixture is subsequently supplied to the second group of heat exchange tubes 17. The vapor-liquid mixture is at about 1.0. 7 m / s estimated # linear speed to the second set of heat exchange tubes 17, wherein the vapor-liquid mixture is further heated to a temperature of 421 ° C, and at this temperature and a pressure of about 834 kPa-a The second set of heat exchange tubes 17 is discharged. At the outlet of the second set of heat exchange tubes 17, the weight percentage of liquid exiting the second set of heat exchange tubes 17 is then reduced to an estimated 8% by weight of the entire stream. The pressure drop of the first set of heat exchange tubes 15 and the second set of heat exchange tubes 17 of the convection section is about 521 kPa. 〇Comparative Example 3 Feed C, Heavy Normal Pressed Gas Oil (HAGO) Feed' has the above Table 1. The properties listed are for the hydrocarbon feed of this example. At a temperature of 99 °C' The feed C having a specific gravity of 0.8566 ml/g and an average molecular weight of 293 was supplied to the inlet of the first group of heat exchange tubes 15 of the convection section 3 at a pressure of 910 kPa-a and a rate of 95 ton / hr. C' is completely liquid at this point, passing through a first set of heat exchange tubes 15 having 8 parallel tubes. The feed C is supplied to the first group at a linear velocity of 1 · 3 3 m/s. The inlet of the convection section heat exchange tube 15. The feed C is heated to a temperature of 256 ° C and discharged as a whole liquid at a pressure of 862 kPa-a. The first group of cooked exchange tubes 156 across the convection section The pressure drop is about 4 8 k P a. The heated feed C exits the first set of heat exchange tubes 15 in a liquid phase and has a linear velocity of -35-200909572 of 32 m/s. Example 3 Feed C Heavy heavy gas oil (HAGO) feed having the properties listed in Table 1 above as the hydrocarbon feed of this example at a temperature of 9 9 ° C, a pressure of 876 kPa-a and 95 Feed C having a specific gravity of 0.8 5 66 ml/g and an average molecular weight of 293 is fed to the inlet of the first set of heat exchange tubes 15 of the convection section 3 at a rate of ton/hr. Time is all liquid Passing through a first set of heat exchange tubes 15 having 8 parallel tubes. The feed C is supplied to the inlet of the first set of convection heat exchange tubes 15 at a linear velocity of 0.82 m/s. Feed C was heated to a temperature of 256 ° C and discharged as a full liquid at a pressure of 8 62 kPa-a. The pressure drop across the first set of heat exchange tubes 15 of the convection section was about 14 kPa. The heated feed C exits the first set of heat exchange tubes 15 in a liquid phase and has a linear velocity of 3 1 .7 m/s. Comparative Example 4 Feed D1, a low sulfur vacuum gas oil (LSVGO) feed having the properties listed in Table 1 above, was used as the hydrocarbon feed of this example. The feed D1 having a specific gravity of 0.9 〇 82 ml/g and an average molecular weight 422 was supplied to the first set of heat of the convection section 3 at a temperature of 110 ° C, a pressure of 724 kPa-a, and a rate of 68 ton / hr. The inlet of the exchange tube 15. The feed D1, at this point, is all liquid and passes through a first set of heat exchange tubes 15 having eight parallel tubes. The feed D 1 is supplied to the inlet of the 364-200909572 set of convection section heat exchange tubes 15 at a linear velocity of 1.31 m/s. The feed d 1 was heated to a temperature of 2 9 2 ° C and discharged at full pressure in a pressure of 6 83 kPa-a. The pressure drop across the first set of heat exchange tubes 15 of the convection section is about 2 17 kPa. The heated feed D1 exits the first set of heat exchange tubes 15 in a liquid phase and has a linear velocity of 17 m / s. Example 4 Feed D1, a low sulfur vacuum gas oil (LSVGO) having the properties listed in Table 1 above, was used as the hydrocarbon feed of this example. The feed D1 having a specific gravity of 0.90 82 ml/g and an average molecular weight 422 was supplied to the first group of heat exchanges of the convection section 3 at a temperature of Π 〇r, a pressure of 730 kPa-a, and a rate of 68 ton / hr. The inlet of the tube 15. The feed D1, at this point, is all liquid and passes through a first set of heat exchange tubes 15 having eight parallel tubes. The feed D 1 is supplied to the inlet of the first set of convection heat exchange tubes 15 at a linear velocity of 0 · 3 m/s. The feed D1 was heated to a temperature of 292 ° C and discharged as a whole liquid at a pressure of 75 8 kPa-a. The pressure drop across the first set of heat exchange tubes 15 across the convection section is about _28 kPa (the negative pressure drop is partially due to gravity). The heated feed D1 exits the first set of heat exchange tubes 15 in a liquid phase and has a linear velocity of 17.4 m/s.

Example 4A Feed D2, low sulfur wax residue (LSWR) feed, having the properties listed in Table 1 above, was used as the hydrocarbon feed for this example. The light crude oil feed D2 having a specific gravity of 0.8787 ml/g is supplied to the convection section 3 at a temperature of 93 ° C -37 - 200909572, a pressure of about 925 kPa-a and a rate of 65 tons / hr - The inlet of the heat exchange tube 15 is grouped. The feed D2, at this point, is all liquid, passing through a first set of heat exchange tubes 15 having eight parallel tubes. The feed d 2 is supplied to the inlet of the first set of convection heat exchange tubes 15 at a linear velocity of 0 · 4 4 m / s. The feed D2 is heated in the first set of heat exchange tubes 15 of the convection section and is discharged at an estimated 1 (10) weight percent liquid phase. The heated feed D2 discharged from the first group of heat exchange tubes 15 and the flow rate of 2.6 tons/hr at 1100 kPa-a and 120 ° C in water and flow rate 15-6 ton / hr at 92 5 kPa-a and 2 1 0 ° C The steam is mixed underneath. After mixing with water and steam, a portion of the hydrocarbon feed is vaporized to form a vapor-liquid mixture having an estimated 94.6 wt% liquid phase based on the total weight of the hydrocarbon feed and the vapor turbulent stream. This vapor-liquid mixture is subsequently supplied to the second set of heat exchange tubes 17. The vapor-liquid mixture is supplied to the second set of heat exchange tubes 17 at an estimated linear velocity of about 23.75 m/s, wherein the vapor-liquid mixture is further heated to a temperature of 45 5 ° C and at this temperature The second set of heat exchange tubes 17 is discharged at a pressure of about 827 kPa-a. At the outlet of the second set of heat exchange tubes 17, the percentage by weight of the liquid exiting the second set of heat exchange tubes 17 is then reduced to an estimated 32% by weight based on the total weight of the hydrocarbons of the entire stream (to the entire stream) The total weight is estimated to be 25% by weight). The pressure drop across the first set of heat exchange tubes 15 and the second set of heat exchange tubes 17 across the convection section is about 9 8 kP a. The following table (Table 2) lists all of the pressure drops of Comparative Examples 1 to 4 and Examples 1 to 4. In addition, feeding the feed -38-200909572 to the first set of heat exchange tubes at a linear velocity of less than 1.1 m/s, achievable across the first set and especially the second set of heat exchangers Lower pressure drop. The pressure drop of the second group of heat exchange tubes of Examples 1 and 2 was less than about 9 times the pressure drop of the second group of heat exchange tubes of Comparative Examples 1 and 2. Due to the low pressure drop, the method of this disclosure has the advantage of supplying a hydrocarbon feed at a lower inlet pressure, which saves the energy required for steam cracking. Moreover, the lower inlet pressure results in a lower outlet pressure at the outlets of the first and second sets of heat exchange tubes, which has the advantage of applying a lower pressure first and second dilution streams. The method of the disclosure provides the advantage of being energy efficient and having steam cracking efficiency by reducing the pressure required for the first and second dilution streams. Table 2 Pressure drop of the first set of heat exchange tubes (kPa) Pressure drop of the second set of heat exchange tubes (kPa) Combined pressure drop of the first and second sets of heat exchange tubes (kPa) Comparative Example 1 21 1448 1469 Implementation Example 1 -9 145 136 Comparative Example 2 21 1027 1048 Example 2 - 10 117 107 Example 2A 521 Comparative Example 3 48 ΝΑ 实施 Example 3 14 ΝΑ ΝΑ Comparative Example 4 41 ΝΑ 实施 Example 4 -28 ΝΑ 实施 Example 4A 98 From the foregoing description, those skilled in the art can readily determine the basic features of the disclosure, and the various changes and modifications of the disclosure can be adapted to different usages and conditions without departing from the spirit and scope thereof. Although the present invention has been described and illustrated with respect to the specific embodiments thereof, it will be apparent to those skilled in the art that For this reason, therefore, for the purpose of determining the true scope of the present invention, reference should be made only to the scope of the appended claims. [Simple description of the drawing] Fig. 1 is a schematic flow chart of the steam cracking furnace for the disclosure. [Main component symbol description] 1 : Steam cracking furnace 3 : Convection section 5 : First preheating zone 7 : First preheating section 9 : Second preheating section 1 1 : Second preheating zone 12 : Hot flue gas 1 3 : radiant section 15: first group of heat exchange tubes 1 7 : second group of heat exchange tubes 1 9 : third group of heat exchange tubes 3 1 : hydrocarbon feed 3 3 : preheating hydrocarbon feed 3 5 : Fluid 3 7 : First Dilution Stream - 40 - 200909572 39 : Vapor - Liquid Mixture Stream 4 1 : Dilution Stream 43 : Heat Exchange Tube 4 5 : Dilution Stream 4 7 : Second Dilution Stream 4 9 '· Fractional Diluted Flow 5 1 : flash stream 53 : container 5 5 : head vapor stream 5 7 : bottom stream 59 : connecting tube % -41 -

Claims (1)

200909572 X. Patent application scope 1. A method for treating a hydrocarbon feed comprising: a. feeding the hydrocarbon feed to a steam cracking furnace at a linear velocity equal to or less than 0. 9 m/s. a first preheating zone of the section; b. preheating the hydrocarbon feed in the first preheating zone to vaporize less than 99% by weight of the hydrocarbon feed to form a vapor-liquid mixture; c_ separating the vapor - Forming at least a portion of the liquid mixture to form a vapor portion and a liquid portion; and d. supplying at least a portion of the vapor portion to the steam cracking furnace. 2 The method of claim 1, wherein the hydrocarbon feed is supplied in a substantial liquid phase. 3. The method of claim 1, wherein the first convection section comprises a plurality of heat exchange tubes and the hydrocarbon feed flows into the tubes. The linear velocity f is the linear velocity f, and the first preheating zone feed system is at a temperature of 690° for a temperature in the range of °C. The preheating hydrocarbon is produced in a preheating section to form a preheating section. Steaming 4. The method of claim 1, wherein the range is from 0.05 to 0.85 m/s. 5. The method of claim 1, wherein the range is from 0.1 to 0.80 m/s. 6 _ The method of claim 1, wherein the first preheating section and the second preheating section comprise a pressure in the range of 1 480 kPa-a and 25 to 25 0. (: Fan should go to the first preheating section to form a preheated hydrocarbon product that exits the first preheating section at about 1 to 35 Torr, and then at least a portion of the product is supplied to the first dilution stream The first step is to discharge the -42.200909572 gas-liquid mixture at a temperature ranging from 35 Torr to 500 ° C. The vapor-liquid mixture is at least 1% by weight based on the total weight of the hydrocarbons in the vapor-liquid mixture. And the vapor-liquid mixture is at a vapor phase of at least 60% by weight based on the total weight of the hydrocarbons in the vapor-liquid mixture. 7. The method of claim 1, wherein the hydrocarbon feed is 1 〇 to 9 9.9 9 wt% boiling at a temperature lower than 590 ° C measured according to ASTM D 2 8 8 7. 8 The method of claim 1, wherein the preheated hydrocarbon product is a substantially liquid phase 9. The method of claim 1, wherein the vapor-liquid mixture has a temperature in the range of 400 to 50 (TC range and comprises at least 2% by weight liquid based on the total weight of the hydrocarbons in the vapor-liquid mixture and Wherein 50 to 99.99% by weight of the hydrocarbon feed is below The method of claim 5, wherein the vapor-liquid mixture has a temperature in the range of 4500 to 500 t and comprises The total weight of hydrocarbons in the vapor liquid mixture is at least 5% by weight liquid and wherein 10 to 99.99% by weight of the hydrocarbon feed boils below 590 ° C as measured according to ASTM D-28 87. 1 1 The method of claim 1, further comprising mixing the second dilution stream with the vapor-liquid mixture prior to the step (c). 1 2 · The method of claim n, wherein the second dilution The stream comprises steam. 1 3 _ - a method of cracking a hydrocarbon feed in a steam cracking furnace having a convection section - 43 - 200909572 'The convection section comprises a first set, a second set and a third set of heat, the method comprising : a_ feeding a hydrocarbon feed having at least 1% by weight of low volatility components and at least a quantity of coke precursor to the heat exchange tubes provided in the convection section and having an inlet linear velocity equal to or less than 〇_9 m/ b; preheating the hydrocarbon feed to form less than 35 (rc a warm hydrocarbon product; c. supplying at least one of the second set of heat exchange tubes of the preheated hydrocarbon product in a first dilution stream to evaporate at least a portion of the hydrocarbon feed having a range of from 350 to 500 °C a temperature and comprising at least 1% by weight of a vapor-liquid of the liquid in the vapor-liquid. d. separation step (c) at least one of the vapor-liquid mixture forms a vapor portion and a liquid portion; and e At least a portion of the vapor portion of step (d) is supplied to the set of heat exchange tubes. 1 4 . The method of claim 13 , wherein the further step (d ) is followed by mixing the second dilution stream to the vapor-liquid mixture $ i 5 — as in the method of claim 13 of the patent scope, further steps (e) a method of previously mixing the vapor portion with a third gas containing steam. The method of claim 13 wherein the hydrocarbon is 10 to 95 percent lower than measured according to ASTM D-2 8 8 7 It is boiling. The exchange tube 〇_1 is heavier than the first part of the first group to form the body mixture mixture portion and the third portion is included. The method of claim 1, wherein the hydrocarbon feed comprises steam cracking gas and oil, gas, oil, and heating. Oil, jet fuel, diesel, kerosene, gasoline, coker naphtha, steam cracking of crude gasoline, catalytic cracking of crude gasoline, hydrocracking products, recombinants, raffinate recombination, Fischer-liquid (Fischer- Tropsch liquid), Fischer-Tropsch gas, Fischer-Tropsch wax, distillate, crude oil, atmospheric pipestill bottom, vacuum tube stillter flow including bottoms, vacuum gas oil, heavy gas oil, One or more of light oil, atmospheric heavy oil, heavy residual oil, C4/residual oil mixture, light oil residual oil mixture and low sulfur wax residue contaminated by crude oil. 1 8 a method for cracking a hydrocarbon feed into a light olefin in a steam cracking furnace having a radiant section burner and a convection section, the convection section comprising the first, second and third sets of heat exchange tubes The method comprises: a. feeding the hydrocarbon feed to a first set of heat exchange tubes provided in the convection section at a pressure in the range of 790 to 1480 kPa-a and a temperature in the range of 25 to 250 °C, and The linear velocity is equal to or less than 0.9 m/s; b _ heat the hydrocarbon feed to form having less than 350. (preheating the hydrocarbon product at a temperature; c. supplying at least a portion of the preheated hydrocarbon product to the second set of heat exchange tubes in a first dilution stream to evaporate at least a portion of the hydrocarbon feed to form 350 to 5 Torr (temperature in the range of TC and comprising at least 1% by weight of liquid vapor-liquid mixture based on the total weight of hydrocarbons in the vapor-liquid mixture* d. Separation step (C) at least a portion of the vapor-liquid mixture Forming a vapor portion and a liquid portion at -45-200909572; and e. supplying at least a portion of the vapor portion of step (d) to three sets of heat exchange tubes. 19. The method of claim 18, wherein the steamed mixture has At a temperature in the range of from 400 to 500. Torr and comprising at least 2% by weight of liquid based on the total weight of the hydrocarbons in the bulk mixture and from 50 to 99.99% by weight of the feed in an amount less than 5 according to ASTM D-amount The method of claim 18, wherein the steamed mixture has a temperature in the range of 425 to 500 ° C and comprises at least 3 weights based on the total weight of the hydrocarbons in the bulk mixture. % liquid and ginger feed 40 to 99.99% by weight is boiling at a temperature lower than 590 ° C according to the AS TM D- quantity. The method of claim 18, wherein the steamed mixture has a temperature of 4500 to 500 ° The temperature in the range of C comprises at least 5% by weight liquid based on the total weight of the hydrocarbons in the bulk mixture, and from 1 Torr to 99.99% by weight of the 5 hydrocarbon feed boiling below 590 °C as measured according to ASTM. 22. The method of claim 18, wherein the total pressure drop of the exchange tube is less than 1 算出 from the discharge point of the first set of heat exchange tubes of the first set of heat exchange tubes. The method of claim 18, wherein the total pressure drop of the through-exchange tube is calculated by the second group of heat exchange tubes at the point of introduction of the second group of heat exchange tubes, and is less than 5 00 kPa. The second gas-liquid vapor-liquid; the hydrocarbon 2 8 8 7 gas-liquid vapor-liquid; the hydrocarbon 28 87 gas-liquid vapor-liquid. wherein the D-2887 丨 group Heat ^ minus this; two groups of heat 4 salt to the -46- 200909572 24. a suitable for steam cracking of hydrocarbon feedstock into light olefins, its package Included: a. a steam cracking furnace comprising a burner adapted to provide radiant heat and hot flue radiant sections and having a first, second and third set of heat exchange convection sections; b _ to be equal to or less than 0 · 9 m a linear velocity of the s into the first set of heat exchange tubes; c_ maintaining the hydrocarbon feed at a temperature below 35 ° C to discharge the set of heat exchange tubes; d. Supplying a first dilution stream with at least a portion of the preheated hydrocarbon from (c) to a first heat exchange tube suitable for vaporizing less than 99% by weight of the hydrocarbon feed to form a vapor-liquid mixture; e. maintaining the vapor a means for discharging the second set of heat exchange tubes at a temperature in the range of from 3 50 to 500 ° C: f. adapted to separate a portion of the vapor-liquid mixture from step (e) to form a vapor portion and a liquid portion a container; and g. a mechanism for supplying at least a portion of the vapor portion from step (f) to the three sets of heat exchange tubes. 25. The apparatus of claim 24, wherein the further dilution (f) of the second dilution stream is mixed with the vapor-liquid mixture of the apparatus 1 device gas for the first product two sets of temperatures at least the first At -47-