The Effect of Coil Configuration on Run Length of Thermal Cracking Reactors

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Ramin Karimzadeh ◽  
Amin Hematian ◽  
Mohammad Reza Omidkhah
Keyword(s):  
Thermal Cracking ◽  
Coke Deposition ◽  
Linear Temperature ◽  
Single Row ◽  
Run Length ◽  
Petrochemical Complex ◽  
Coil Temperature ◽  
Temperature Heat ◽  
Temperature And Pressure ◽  
Pyrolysis Coil

Various parameters such as type of feedstock, inlet and outlet coil temperature, heat flux and residence time, affect the performance of a thermal cracking reactor. The pyrolysis coil configuration is one of the most important parameters which affects the performance of the reactor.In this research the effect of four different coil configurations, namely single row, millisecond, split and reversed split have been studied on run length, product yields, outside surface temperature of coil, coke deposition as well as temperature and pressure distribution. The reactor under investigation is the thermal cracker of Abadan petrochemical complex which uses propane as feedstock. The results show that millisecond coil configuration has the highest yield of ethylene and lowest coke thickness. However, it exhibits the lowest run length and worst ratio of length to diameter conditions. On the other hand, single row coil configuration has the lowest ethylene yield and highest coke thickness but, the highest run length with the lowest pressure drop also belongs to this coil configuration. It also presents the most even distribution of pressure and a linear temperature profile across the coil length, favoring better selectivity.

Coke Deposition Influence Based on a Run Length Simulation of a 1,2-Dichloroethane Cracker

2013 ◽  
Vol 52 (49) ◽  
pp. 17501-17516 ◽  
Author(s):  
Chaochun Li ◽  
Guihua Hu ◽  
Weimin Zhong ◽  
Wangli He ◽  
Wenli Du ◽  
...  
Keyword(s):  
Coke Deposition ◽  
Run Length

scholarly journals Performance and Optimization Study of R290 as Alternative Refrigerant for R22 in Low Temperature Heat Pump System

2021 ◽  
Vol 2108 (1) ◽  
pp. 012089
Author(s):  
Yun Zhang ◽  
Cichong Liu ◽  
Wanyong Li ◽  
Junye Shi ◽  
Jiangping Chen
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Exhaust Temperature ◽  
Discharge Temperature ◽  
Temperature Environment ◽  
Temperature Heat ◽  
Overall Performance ◽  
Temperature And Pressure

Abstract This paper mainly studies the replacement performance of R290 in R22 low temperature heat pump system from the experimental point of view. By comparing the performance differences under different working conditions, it is found that when R22 is directly extracted from the original system and filled with R290, the heat capacity and COP of the system are attenuated, and the compressor discharge temperature and pressure of the R290 system are higher than those of the original R22 system in low temperature environment. Through the analysis of the system components, it can be considered that the main reason for the above phenomenon is that the compressor displacement of the R22 system is too large and does not match the R290 system. Therefore, in order to meet the safety requirements of the system and improve the overall performance of R290 in the low temperature heat pump system at the same time, it is considered to replace the compressor with a smaller displacement which is more matched with R290 in the system. The experimental results show that the compressor displacement optimization of the R290 low temperature heat pump system can effectively reduce the exhaust temperature and pressure of the system and improve the overall performance of the system. The COP of the optimized R290 low temperature heat pump system is 6.5% higher than that of the original R22 system, and the exhaust temperature in the low temperature environment is reduced by 36% to below 80 C.

Coke deposition in the thermal cracking of ethane

AIChE Journal ◽  
1981 ◽  
Vol 27 (6) ◽  
pp. 946-951 ◽  
Author(s):  
K. M. Sundaram ◽  
P. S. Van Damme ◽  
G. F. Froment
Keyword(s):  
Thermal Cracking ◽  
Coke Deposition

Deposit Formation and Mitigation in Aircraft Fuels

1999 ◽  
Vol 123 (4) ◽  
pp. 741-746 ◽  
Author(s):  
L. J. Spadaccini ◽  
D. R. Sobel ◽  
H. Huang
Keyword(s):  
Heat Flux ◽  
Heat Exchanger ◽  
Residence Time ◽  
Carbon Deposition ◽  
Operating Conditions ◽  
Coke Deposition ◽  
Jet Fuels ◽  
Fuel Temperature ◽  
Temperature Heat ◽  
Selection Of

The development of a viable strategy for limiting coke deposition involves combining synergistic approaches for suppressing deposit buildup and reducing its impact on performance. Candidate approaches, including selection of favorable operating conditions (viz., pressure, temperature, heat flux, residence time, and passage size) and coke-tolerant heat exchanger designs, were investigated to evaluate their effectiveness and provide a basis for combining them into a single design philosophy. These approaches were evaluated through testing of current jet fuels in single-tubes and segments of heat exchanger configurations at temperatures up to 1000°F, pressures up to 1200 psi and liquid hourly space velocities up to 40,000/h. A key result of this work is the ranking of the importance of heat exchanger operating conditions on carbon deposition, with fuel temperature and those parameters that control species diffusion having the most pronounced impact. Residence time and pressure are of lesser importance. Alternative coke-tolerant heat exchanger designs featuring interchannel communication were evaluated and ranked, with several of these concepts demonstrating improvement over continuous passages.

Aluminized Steel and Zinc Coating for Reduction of Coke Formation in Thermal Cracking of Naphtha

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Aligholi Niaei ◽  
Darioush Salari ◽  
Jafar Towfighi ◽  
Ahad Chamandeh ◽  
Reza Nabavi
Keyword(s):  
Electron Microscope ◽  
Coke Formation ◽  
Zinc Coating ◽  
Thermal Cracking ◽  
Coke Deposition ◽  
Metal Powders ◽  
Spray Method ◽  
Aluminized Steel ◽  
Different Temperatures ◽  
Scanning Electron

Rate of coke formation during steam pyrolysis of naphtha has been investigated in a laboratory CSTR reactor both for uncoated SS321 and metal coating constructed with thermal spray method with metal powders of aluminum, aluminum-magnesium and zinc. Rate of coke formation was studied in different temperatures and amount of coke as a function of run time has been studied too. The results of the study show that passivating the surface of SS321 with a coating of aluminum and aluminum-magnesium can significantly reduce the rate of coke deposition during naphtha pyrolysis. The results obtained from zinc coated show decoking carry out during thermal cracking. The scanning electron microscope (SEM) was carried out for morphology studied of coke deposited on the different metal surfaces.

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