Title of design (thesis): design of packed distillation tower with an annual capacity of 10,000 tons of toluene-water mixture
Correspondence station: Specialization: chemical process Class: xx
Student: xx Instructor:
1. The main tasks and objectives of the design (thesis)
Calculation of the tower design:
a Tower process calculations:
b Tower process calculations (material and energy accounting)
b Tower design calculations:
a tower process calculations (material and energy accounting)
b tower and tower plate design calculations of the main process dimensions
(3) on the benzene distillation tower hydrodynamic calculations
(4) the relevant auxiliary equipment selection and calculation
(5) the design results and analysis of the discussion
2. Design (thesis) of the basic requirements and contents
(1) The content of the thesis conforms to the specification for writing graduation designs.
(2) The data is reliable, true and representative.
(3) The calculation process is refined and conforms to the specification requirements.
(4) Requirements for the thesis drawings include: production process flow control diagrams, part of the tower assembly diagram, X-Y diagrams, tower plate loading performance diagram.
3. Main references
(1) Lu Meijuan. Principles of Chemical Engineering. Chemical Industry Press. 1st edition, January 2001
(2) Feng Bohua. Handbook of Chemical Engineering, Vol. 1, 2, 3, 6. Chemical Industry Press. 1st edition, October 1989
(3) Bao Piqin. Hua engineering principles course design guide book. Beijing University of Chemical Technology Principles of Chemical Engineering Teaching and Research Department.April 1997
(4) Hongfang Chen. Chemical Separation Processes. Chemical Industry Press. 1st edition, May 1995
(5) Chen Zhongxiu. Chemical Thermodynamics. Chemical Industry Press. 1, November 1993
Keywords: reflux ratio, distillation, bubble point feed, equipment, test differential
Contents
Preface ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (7)
Chapter 1 Description of the Distillation Program ．．．．．．．．．．．．．．．．．．．．．．． (7)
Section 1.1 Operating Pressures ．．．．．．．．．．．．．．．．．．．．．．．．．．．． (7)
Section 1.2 Feed Status ．．．．．．．．．．．．．．．．．．．．．．．．．．．． (8)
Section 1.3 Use of Forced Reflow (Cold Reflow) ．．．．．．．．．．．．．．． (8)
Section 1.4 Tower kettle heating method, heating medium ．．．．．．．．．．．．．． (8)
Section 1.5 Condensation at the top of the tower, cooling medium ．．．．．．．．．．．．．． (8)
Section 1.6 Process description ．．．．．．．．．．．．．．．．．．．．．．．．．．．． (8)
Section 1.7 Characteristics of Sieve Plate Tower ．．．．．．．．．．．．．．．．．．．．．．．． (9)
Section 1.8 Production properties and uses ．．．．．．．．．．．．．．．．．．．．．． (9)
Section 1.9 Safety and Environmental Protection ．．．．．．．．．．．．．．．．．．．．．．．．．． (11)
Chapter 2 Olefin Hydrogenation and Saturation Unit Analysis ．．．．．．．．．．．．．．．．． (12)
Section 2.1 Reaction Mechanism and Analysis of Influencing Factors
Section 2.2 Material Balance
Section 2.3 Energy Balance
Chapter 3 Distillation Tower Design Calculations ．．．．．．．．．．．．．．．．．．．．．．． (12)
Section 3.1 Process Calculations for Towers ．．．．．．．．．．．．．．．．．．．．．．. (12)
Section 3.2 Design Calculations for Major Process Dimensions of Towers and Plates ．．．．. (25)
Chapter 4 Hydrodynamic Calculations for Towers ．．．．．．．．．．．．．．．．．．．．． (31)
Section 4.1 Calibration ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (31)
Section 4.2 Load Performance Plot Calculations ．．．．．．．．．．．．．．．．．．．．．． (34)
Chapter 5 Auxiliary Equipment Sizing Calculations ．．．．．．．．．．．．．．．．．．．．． (39)
Section 5.1 Calculation of Heat Exchanger Selection ．．．．．．．．．．．．．．．．．．．． (39)
Section 5.2 Pipe Sizing ．．．．．．．．．．．．．．．．．．．．． (44)
Section 5.3 Determination of raw material and finished product tanks ．．．．．．．．．．．．．．．． (45)
Chapter 6 Summary of Design Results and Analysis and Discussion ．．．．．．．．．．．．．．． (45)
Section 6.1 Data Requirements ．．．．．．．．．．．．．．．．．．．．．．．．．．．． (45)
Section 6.2 Design Features ．．．．．．．．．．．．．．．．．．．．．．．．．．．． (46)
Section 6.3 Problems ．．．．．．．．．．．．．．．．．．．．．．．．． (46)
References ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (47)
Description of symbols ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (48)
Appendix 1 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (52)
Appendix 2 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (52)
Appendix 3 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (52)
Appendix 4 ．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． (52)
Preface
This thesis is a program for the purification and distillation of benzene in the binary system of benzene-toluene solution for industrial production, and the design and material accounting of the distillation columns are carried out on the basis of the given nature and composition of the raw materials and the nature and composition of the products. Through the design of accounting and test differential calculations to determine the preliminary distillation tower feed, tower top, tower bottom operating conditions and material composition. At the same time on the basic structure of the distillation tower, including the main dimensions of the tower were calculated and selected, the top of the tower condenser, the bottom of the tower reboiler, the size of the relevant piping and tanks and other calculations and selection. In the process of calculating and designing, reference was made to the information about "Principles of Chemical Engineering", "Chemical Engineering Handbook", "Cold Exchange Equipment Process Calculation Manual", "Basic Knowledge of Refining Equipment", "Petroleum Processing Unit Process Principles", etc., which provided technical support and guarantee for the design calculation of the distillation tower.
Through the design of distillation columns and material accounting calculations, further deepen the depth of understanding of chemical principles, principles of petroleum processing unit process, etc., broaden the horizons, improve the calculation, drawing, computer use and other aspects of knowledge and ability, for the future in the work of further role in laying a good foundation.
Chapter 1 Description of the distillation program
This distillation program is applicable to industrial production of benzene-toluene solution in the binary system for the purification of benzene. Distillation tower benzene tower products require high purity, up to 99.9% or more, and requires the top of the tower, the bottom of the tower products at the same time qualified, as well as the two tower top temperature change is very narrow (0.02 ℃), the ordinary distillation temperature control is far from reaching this requirement. Therefore, in the actual production process control only using sensitive plate control to meet the requirements. Therefore, the benzene tower using temperature control.
Section 1.1 operating pressure
Distillation operation at atmospheric pressure, because of the low boiling point of benzene, suitable for operation at atmospheric pressure without the need to decompression or pressurized operation. At the same time, the benzene system is not easy to decomposition, polymerization and other metamorphic reactions at high temperatures and is a liquid (not a mixture of gases). Therefore, it is not necessary to use pressurized or depressurized distillation. On the other hand, pressurized or decompression distillation energy consumption, can operate at atmospheric pressure in the system generally do not need to pressurized or decompression distillation.
Section 1.2 State of Feed
The state of feed directly affects the relative positions of the feed line (q-line), the operating line, and the equilibrium relationship, and it also has a significant effect on the heat accounting of the entire column. Compared with the bubble point feed: if the cold feed, under the condition of certain separation requirements need less theoretical number of plates, no preheater, but the tower kettle heat load (generally need to use direct steam heating) from the total heat to see the basic balance, but the feed temperature fluctuation is large, the operation is not easy to control; if the dew point feed, then under the condition of certain separation requirements, the number of theoretical plates required, the preheater before the feeding of a large load, large energy consumption, the distillation section and the distillation section. At the same time, the distillation section and distillation section of the rising steam volume changes, the operation is not easy to control, by the external conditions.
Bubble feed between the two, the biggest advantage is that the external interference is small, the distillation section of the tower, distillation section of the rising steam volume changes are small, easy to design, manufacture and operation control.
Section 1.3 forced reflux (cold reflux)
The purpose of the cold reflux is to facilitate the control of the reflux ratio, the reflux method of reflux temperature has a direct impact.
Section 1.4 kettle heating method, heating medium
The tower kettle adopts tube heat exchanger as reboiler indirect heating method, the heating medium is water vapor.
Section 1.5 Condensation method and cooling medium at the top of the tower
The top of the tower adopts tube condensation cooler, and the cooling medium is cooling water.
Section 1.6 Process description
Because there is no post-hydrogenation unit in the upstream unit, the olefins generated in the process of reforming reaction will be brought into the feedstock of this unit, and the presence of olefins will lead to unqualified pickling colorimetry of the benzene and toluene products, so it is necessary to carry out the hydrotreating of olefins saturation.
The process of this unit consists of two parts: olefin hydrogenation reaction unit and distillation unit.
Olefin hydrogenation reaction unit: the raw material is pressurized by the feed pump into the heat exchanger E101 and the reaction of the oil exchange of heat, into the heating furnace L101 heating, and then into the reactor R101, after the olefin saturated hydrogenation reaction into the heat exchanger E101 cooling, into the oil and gas separator V101, the oil into the distillation of raw materials intermediate tank.
This distillation program adopts energy-saving forced reflux for process design, and comes with an automatic control system to ensure normal operation under constant feed volume, feed composition and certain separation requirements.
Distillation process: 30OC raw liquid from the raw material tank through the feed pump into the raw material heat exchanger E102 and then through the raw material preheater for preheating and further preheating to the bubble point (97.65OC, the heating medium for the water vapor), the temperature rises to about 97.65oC, from the feed port into the distillation tower T101 for distillation, the top of the tower gas temperature of 81.52oC part of the condensed gas-liquid The gas-liquid mixture after partially condensed enters the cooler at the top of the tower (the cooling medium is cooling water), and the condensed material enters the reflux tank V102, and then through the reflux pump, part of the material liquid as reflux is also pumped into the top of the tower, and the other part as the product at the top of the tower through the product cooler enters the product tank V103, and then the product is transported by the product pump P104/AB. Part of the liquid in the tower kettle enters the reboiler E103, which is heated by water vapor and refluxed to the tower kettle, and the other part is discharged into the toluene storage tank after heat exchange with the raw material heat exchanger. Throughout the process, all pump outlets are equipped with pressure gauges, and all storage tanks are equipped with venting valves to ensure that atmospheric pressure is maintained in the tanks.
Section 1.7 Characteristics of Sieve Plate Tower
Sieve plate tower is one of the earliest plate towers used, and its main advantages:
(1) simple structure, easy to process, the cost of about 60% of the blister tower, about 80% of the floating valve tower;
(2) in the same conditions, the production capacity of the tower than blister tower 20%-40% larger;
< p>(3) the tower plate efficiency is higher, about 15% higher than the blister tower, but slightly lower than the float valve tower;(4) the gas pressure drop is smaller, the pressure drop per plate is about 30% lower than the blister tower.
The disadvantage of sieve plate tower is: small hole sieve plate is easy to clog, not suitable for dealing with dirty, viscous and with solid particles of the material liquid.
Section 1.8 Properties and Uses
1.8.1 Properties and Uses of Benzene
Benzene is a kind of flammable, volatile, poisonous, colorless and transparent liquid, flammable with a special aromatic odor liquid. Molecular formula C6H6, relative molecular weight 78.11, relative density 0.8794 (20 ℃), melting point 5.51 ℃, boiling point 80.1 ℃, flash point -10.11 ℃ (closed cup), spontaneous combustion point of 562.22 ℃, vapour density of 2.77kg/m3, vapour pressure of 13.33kPa (26.1 ℃), the standard specific gravity of 0.829. vapour and air mixture explosion Explosive limit of vapor-air mixture 1.4%～8.0%. Insoluble in water, miscible with ethanol, chloroform, ether, carbon disulfide, carbon tetrachloride, glacial acetic acid, acetone, oil. Easy to burn and explode when exposed to heat and open flame. Can react violently with oxidizing agents such as bromine pentafluoride, chlorine, chromium trioxide, perchloric acid, nitroxide, oxygen, ozone, perchlorate, (aluminum trichloride + fluorine perchlorate), (sulfuric acid + permanganate), potassium peroxide, (aluminum perchlorate + acetic acid), sodium peroxide, can not be with ethylborane ****exist. Benzene is one of the carcinogens. Benzene is an important raw material for dyestuffs, plastics, synthetic resins, synthetic fibers, drugs and pesticides, etc. It can also be used as a power fuel and a solvent for paints, rubber and glue. Quality standard: see Table 1-1.
Table 1-1 Quality standard of pure benzene (GB/T2283-93)
Items Indicators
Extraordinary First Grade Second Grade Third Grade
Appearance Transparent liquid at room temperature (18~25℃), not deeper than 0.003g of potassium dichromate solution per 1000mL of water. color
Density (20 ℃)/kg/m3
Boiling range / ℃
Atmospheric pressure (80.1 ℃)
Acid wash color
Bromine valence / (g/100mL)
Crystallization point / ℃
Carbon disulphide / (gBr/100mL)
Thiophene / (g/ 100mL) 876~880 100mL) 876~880
Neutral test Neutral
Moisture No visible insoluble water visually at room temperature (18~20°C)
1.8.2 Properties of toluene
Toluene has a strong aromatic odor, colorless refractive force of volatile liquids, the smell like benzene. Molecular formula C7H8, relative molecular mass 92.130, relative density 0.866 (20 ℃ / 4 ℃), melting point -95 ~ -94.5 ℃, boiling point 110.4 ℃, flash point of 4.44 ℃ (closed cup), spontaneous combustion point of 480 ℃, vapour density of 3.14 kg / m3, vapour pressure of 4.89kPa (30 ℃) Specific gravity of D 4 ℃, 20 ℃, 0.866,, the vapor and air mixture explosion limit of 1.5 ℃. The explosion limit of air mixture is 1.27% to 7%. Almost insoluble in water, miscible with ethanol, chloroform, ether, acetone, glacial acetic acid, carbon disulfide. Easily catch fire when exposed to heat, open flame or oxidizer. Can cause explosion when exposed to open flame or react with (sulfuric acid + nitric acid), nitrogen tetroxide, silver perchlorate, bromine trifluoride, uranium hexafluoride and other substances. The flow rate is too fast (more than 3m/s) and there is a danger of generating and accumulating static electricity. Toluene can be chlorinated, nitrified, sulfonated, oxidized and reduced before dyes, pharmaceuticals, spices and other intermediates and explosives, refined sugar. Since the crystallization point of toluene is very low, it can be used as additive of aviation fuel and internal combustion engine fuel. Quality standards: see Table 1-2.
Table 1-2 Toluene quality standards (GB/T2284-93)
Items Indicators
Extraordinary Grade First Grade Second Grade
Appearance Transparent liquid at room temperature (18~25 ℃), not deeper than 0.003g of potassium dichromate solution per 1000mL of water. Color
Density (20℃)/(kg/m3)
Boiling range/℃
Atmospheric pressure (110.6℃)
Acid wash colorimetry
Bromine valence/(gBr/100mL) 863~868
Neutral experiment Neutral
Moisture At room temperature (18~20℃) visual inspection no Visible Insoluble water
Section 1.9 Safety and Environmental Protection
1.9.1 Safety Precautions
Benzene products are flammable, explosive, toxic, colorless and transparent liquids, and their vapors can form explosive mixtures when mixed with air, so special attention should be paid to fire prevention and strengthened safety measures.
(1) no open flames and sparks, the equipment must be sealed to reduce the benzene vapor volatility emitted into the container, the equipment should be open to the atmosphere of the discharge pipe, the mouth of the pipe with a fine metal mesh cover, so that the storage tanks or distillation equipment in the benzene products do not cause combustion due to the backfire of the vapor dispersed, the plant should be equipped with good ventilation to prevent the benzene vapors from aggregating.
(2) all metal structures should be grounded in several locations, in order to prevent the free fall of liquid caused by the generation of static charge, will be introduced into the storage tank all piping should be installed close to the bottom of the storage tank, the motor should be placed in a separate plant.
(3) should be equipped with foam fire extinguishers and steam fire extinguishing devices, can not use water to extinguish fires.
(4) before workers enter the tank or equipment cleaning or repair, the oil must be completely drained, all pipelines need to be cut off, the equipment should be thoroughly cleaned with water vapor before being allowed to enter and pay attention to the ventilation, overhauling the personnel do not have a fire certificate is strictly prohibited in the production area fire.
(5) into the production area or production of unrelated personnel, shall not mess with the equipment and measuring instruments.
(6) timely removal of equipment and pipeline leakage, to prevent poisoning fire, explosion and other accidents.
(7) leakage emergency treatment quickly evacuate the leakage of contaminated area to the safe area, and isolation, strict restrictions on access. Cut off the source of ignition. It is recommended that emergency personnel wear self-contained positive-pressure respirators and fire protective clothing. Cut off the source of leakage as far as possible, and prevent access to restricted spaces such as sewers and flood drains. Small leaks: Absorb with activated carbon or other inert materials. It can also be brushed with an emulsion made of a non-flammable dispersant, and the wash solution diluted and put into the wastewater system. Large quantity leakage: construct a dike or dig a pit to shelter; cover with foam to inhibit evaporation. Use explosion-proof pumps to transfer to the tanker or special collector, recycling or transported to the waste disposal site.
1.9.2 Environmental protection
Conscientiously implement the environmental protection guidelines, policies, and adhere to the pollution prevention and control facilities and production facilities at the same time as the design, construction, and put into operation at the same time. The "three wastes" management measures are analyzed as follows:
(1) Wastewater: the indirect cooling water of each equipment is recycled for coke quenching in the coking workshop, and the separated water of process products is sent to biochemical devices for treatment. Equipment rinse water is sent to biochemical treatment after preliminary precipitation and oil-water separation.
(2) Exhaust gas: water condensation gas recycling is introduced into the column tube household before combustion, the product storage tank with water spraying device and nitrogen sealing measures to prevent volatilization and pollution of the atmosphere.
(3) waste residue: waste residue produced in the production process is sent to the recycling section for use as raw materials.
Periodic testing of the benzene content of the production positions and the production of water under the pollution of all content, to prevent the occurrence of excessive phenomena.
Chapter 2 Olefin Hydrogenation and Saturation Unit Analysis
2.1 Reaction Mechanism and Influencing Factors Analysis
(1) Reaction Mechanism
Mono Olefin CnH2n+H2→CnH2n+2
Dual Olefin CnH2n-2+2H2→CnH2n+2
Cycloalkene
Olefins
Olefin. Hydrogenation and saturation reactions are also hydrogen-consuming and exothermic.
(2) Influencing factors of the hydrogen saturation reaction process of olefins
The influencing factors of the hydrogen saturation reaction process of olefins, in addition to the performance of the catalyst, are the nature of the feedstock, the reaction temperature, the reaction pressure, the ratio of hydrogen to oil, and the airspeed and so on.
①Property of feedstock
The processing of feedstock with higher olefin content requires higher reaction harshness (i.e., higher reaction pressure and reaction temperature, lower reaction air velocity). In addition attention must be paid to the inert gas protection of the feedstock tank, preferably directly into the device, to avoid intermediate contact with air oxidation occurs to generate gum, resulting in accelerated catalyst deactivation.
②Reaction Temperature
Reaction temperature usually refers to the average temperature of the catalyst bed. Olefin hydrogenation and saturation reaction is an exothermic reaction, increase the reaction temperature is not conducive to the chemical equilibrium of the hydrogenation reaction, but can significantly increase the chemical reaction rate, improve the depth of refining. Too high a reaction temperature will promote the occurrence of hydrocracking side reactions, which will reduce the product liquid yield and lead to an accelerated rate of carbon buildup on the catalyst, reducing the catalyst service life; a reaction temperature that is too low does not guarantee that impurities will be removed.
At very high temperatures, there is a significant limit to olefin saturation, resulting in more residual olefins in the product at higher temperatures than at lower temperatures. When there is a significant light component in the feedstock, hydrogen sulfide reacts with the olefins to form alcohols when using a new catalyst, and the formation of mercaptans can be avoided by operating at lower temperatures.
Depending on the catalyst activity and the olefin content of the feed oil, the general reaction temperature for pre-hydrogenation is 150 to 180 degrees Celsius. As the operating time increases, the reaction temperature is gradually increased to compensate for the decrease in catalyst activity.
③Reaction pressure
When a certain product quality is required, the selection of pressure is mainly to consider the service life of the catalyst and the olefin content of the feed oil. Generally speaking, the higher the pressure, the longer the catalyst operating cycle; the higher the olefin content of the feed oil, the higher the operating pressure. Increasing the reaction pressure will promote the rate of hydrogenation reaction, increase the depth of refining, and can maintain the activity of the catalyst. However, too high a pressure will promote hydrocracking reaction, so that the total liquid yield of the product decreases, and at the same time too high a reaction pressure will increase the investment and operating costs.
④Hydrogen-oil ratio
The so-called hydrogen-oil ratio is the ratio of the hydrogen flow rate to the feed volume when reflecting the standard condition. It can be expressed as H2/HC. Increasing the hydrogen-oil ratio is not only beneficial to the hydrogenation reaction, but also prevents coking and protects the catalyst. However, in the case of a certain feed of raw material oil, the hydrogen-oil ratio is too large to reduce the contact time between the raw material oil and the catalyst, but unfavorable to the hydrogenation reaction, resulting in a decrease in the depth of purification, product quality, but also increase the system pressure drop and compressor load, the operating costs increase.
5 Airspeed
Airspeed refers to the amount of feedstock processed per unit time per unit (mass or volume) of catalyst, abbreviated as h-1 . Airspeed is divided into mass airspeed and volume airspeed. The volumetric space velocity (LHSV) is commonly used, and its reciprocal corresponds to the reaction contact time, which is called the pseudo-contact time. Therefore, the size of the airspeed means the contact time between the feedstock and the catalyst. If the airspeed is too large, i.e., the more feedstock the unit catalyst handles, the shorter the contact time should be, which affects the refining depth; if the airspeed is too small, it increases the hydrocracking reaction, which decreases the product liquid yield, shortens the operation cycle, and reduces the processing capacity of the device.
2.2 Material Balance
Table 2-1 Olefin Hydrocracking Reaction Unit Material Data Unit: Tons/Day
Input Output
Feedstock Oil 43.2 Distillation Feed 42.32
Hydrogen 0.52 Loss 1.40
Total 43.72 Total 43.72
2.3 Energy Balance (taking heating furnace as an example)
2.3.1 Data of raw materials in and out of the heating furnace
Data of raw materials in and out of the heating furnace are shown in Table 2-2.
Table 2-2 Data of raw materials in and out of the heating furnace
Input (80℃) Output (160℃)
Unit
Item Composition Data Enthalpy Calorific Value Unit
Item Composition Data Enthalpy Calorie Unit
m% Kcal/kg wkcal m% Kcal/kg wkcal
Raw
Material
Oil Benzene 0.7 130 16.38 Raw
Material
Oil Benzene 0.7 154 19.40
Toluene 0.3 128 6.912 Toluene 0.3 158 8.532
Olefin Olefin
Hydrogen 540 1.170 Hydrogen 1090 2.362
Total 24.462 Total 30.294
Note: The olefin content of raw materials is very small and can be ignored in the process of calculation.
2.3.2 Heat balance of the heating furnace
From Table 2-2, we can know that the raw material oil through the heating furnace, the heat increase value is: 5.832wkcal/t.
The heating furnace needs to burn gas to provide. The composition of gas for the heating furnace is shown in Table 2-3.
Table 2-3 Composition and enthalpy calculation of gas for the heating furnace
Composition Volumetric calorific value Enthalpy of analysis data
1 Hydrogen 2650 44.91 1190.115
2 Oxygen 0 11.73 0
3 Nitrogen 0 40.56 0
4 Carbon dioxide 0.02 0
5 Carbon monoxide 3018 0 0
6 Methane 8529 1.61 137.3169
7 Ethane 15186 0.48 72.8928
8 Ethylene 14204 0.42 59.6568
9 Propane 21742 0.05 10.871
10 Propylene 20638 0.07 14.4466
11 Isobutane 26100 0.03 7.83
12 n-Butane 28281 0.03 8.4843
13 n-Butene 27160 0.02 5.432
14 Isobutene 27160 0.01 2.716
15 Anti-butene 27160 0.02 5.432
16 Cis-butene 27160 0.01 2.716
17 Above Carbon Pentaphyllene 34818 0.03 10.4454
Total 100 1528.3548
Chapter 7 References
1 Principles of Chemical Engineering, Upper and Lower Books. Chemical Industry Press. 3rd edition, May 2006
2 Feng Bohua. Handbook of Chemical Engineering, Volumes 1, 2, 3, 6. Chemical Industry Press. 1st edition, October 1989
3 Bao Piqin. The principles of chemical engineering course design guidebook. Principles of Chemical Engineering Teaching and Research Department, Beijing University of Chemical Technology.April 1997
4 Hongfang Chen. Chemical Separation Processes, Chemical Industry Press, 1st edition, May 1995
5 Chen Zhongxiu. Chemical Thermodynamics. Chemical Industry Press. 1st edition, November 1993
6 Shen Fu et al. Principles of Petroleum Processing Unit Processes, Upper and Lower Books. China Petrochemical Press. 1st edition, August 2004
7. Liu Wei et al. Cold Exchange Equipment Process Calculation Manual. China Petrochemical Press. September 2003, 1st edition
8. Ma Bingqian, ed. Basic Knowledge of Refining Equipment" Sinopec Press. 1st Edition, January 2003
9.Zhou Zhicheng et al. Petrochemical Instrumentation Automation China Petrochemical Press. 1st Edition, May 1994
10.Tian Guhui. Chemical Equipment, China Petrochemical Press. 1st Edition, June 1996
11.Shen Fu Li Yangchu. Principles of Petroleum Processing Unit Processes, China Petrochemical Publishing House. 1st Edition, August 2004
12. Principles of Chemical Engineering, Chemical Industry Press. January 2006, 10th edition
Description of symbols
A heat transfer area m2
Aa area of bulging area m2
Af cross sectional area of descending tube m2
An area of effective mass transfer area m2
Ao area of sieve holes m2
AT cross sectional area of tower m2
A mass Fraction -
C Load factor -
CP Specific heat KJ/Kg.OC (KJ/Kg.K)
D Product flow rate at the top of the column Kmol/h (Kg/h)
Dg Nominal diameter m
DT Column diameter m
D Pipe inner diameter mm
d1 Pipe outer diameter mm
do Orifice mm
dm Tube Average Diameter mm
E Fluid Flow Shrinkage Coefficient -
ET Full Plate Efficiency -
ev Fog Foam Entrainment Kg Liquid/Kg Gas
F Feed Flow Rate Kmol/h (Kg/h)
H Column Height m
HL Plate Clearance Night Layer Height mm
HT Plate Spacing m
Hd Clear Night Layer Height in Drop Tube m
HD Headspace Height at Top of Tower m
HB Headspace Height at Bottom of Tower m
hd Pressure Drop of Gas through Dry Plate m
ho Distance from Bottom Edge of Drop Tube to Plate m
how Height of Header on Overflow Weir m
hp Pressure Drop of Gas through Tower Wrench m
hp Gas Pressure drop through the tower wrench m
hr Pressure drop of liquid through the drop tube m
hw Height of the overflow weir m
hσ Pressure drop due to liquid surface tension m
Ko Total heat transfer coefficient based on the inner wall Kcal/m2.H.oC
K Stabilization coefficient
L Flow rate of liquid Kmol/h (Kg/h, m3/h)
How the header height on the relief weir m
h h,m3/h)
lW Overflow weir weir length
ms Coolant mass flow rate Kg/h
N Actual number of plates -
NT Theoretical number of plates -
Nt Total number of tubes in the heat exchanger -
N Number of orifices
Q Heat exchanger heat load W
R Reflux ratio -
Rmim Minimum Return Ratio -
Rsi Fouling Resistance Coefficient in Heat Exchanger Tubes m2?h?oC/Kcal
r Latent Heat of Vaporization KJ/Kg
Tc Critical Temperature K
T Orifice Pitch mm
Tp Plate Thickness mm
ua Velocity of Gas based on the Area of the Bubble Zone m/s
uf Liquid flooding gas velocity m/s
un Empty tower gas velocity m/s
uo Gas velocity based on sieve area m/s
uow Leakage point gas velocity m/s
V Rising gas flow rate in the tower Kmol/h(Kg/h,m3/h)
W Liquid extracted from the tower kettle Kmol/h(Kg/h)
Wc Width zone of the marginal zone Kmol/h(Kg/h)
The thickness of the plate mm
Ua Bubble zone area as the basis
Wc Width of rim zone m(mm)
Wd Width of drop tube m(mm)
Ws Width of stabilized zone at plate inlet m(mm)
Ws' Width of stabilized zone at plate outlet m(mm)
X Liquid phase molar fraction -
Y Gas phase molar fraction -
A Relative volatility -
Ai Heat transfer film coefficient based on inner wall Kcal/m2?h?oC
Ao Heat transfer film coefficient based on outer wall Kcal/m2?h?oC
β Inflatability coefficient -
σ Surface tension dyn/cm2
ρL Liquid phase density Kg/m3
ρv(g) Gas phase density Kg/m3
μ Viscosity Cp
Open porosity -
Ф Charging coefficient -
τ Dwell time s
λ