Temperature Control during Mixing of Rubber Compounds

1955 ◽  
Vol 28 (4) ◽  
pp. 1157-1165
Author(s):  
Frank L. Roth ◽  
George E. Decker ◽  
Robert D. Stiehler
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Temperature Control ◽  
Practical Method ◽  
Manual Control ◽  
National Bureau ◽  
Heat Transfer Characteristics ◽  
Considerable Time ◽  
Automatic Temperature Control ◽  
Rubber Compounds

Abstract A study was made of the effect of the surface temperature of the rolls of a 6 × 12-inch laboratory mill on the properties of GR-S compounds and means of controlling this temperature. It was found that the properties of the GR-S compound depend on the surface temperature of the mixing rolls. No practical method of controlling the temperature of conventional rolls was found because of the slow rate of heat transfer. Therefore three types of special rolls, including one designed at the National Bureau of Standards, were investigated. The heat transfer characteristics of the NBS rolls permitted automatic control of their temperatures to within 7° F during mixing of natural rubber and several synthetic elastomers, with only one controller being used. A mill with the special NBS rolls has been in operation for about a year, and has resulted in a marked improvement in the control of mixing of rubber compounds. The automatic temperature control has been much more convenient than manual control, and has saved considerable time, since the rolls do not have to be warmed by milling scrap rubber.

scholarly journals Modeling Study on Heat Transfer in Marangoni Dropwise Condensation for Ethanol-Water Mixture Vapors

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6726
Author(s):  
Jinshi Wang ◽  
Ziqiang Ma ◽  
Yong Li ◽  
Weiqi Liu ◽  
Gen Li
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Temperature Difference ◽  
Diffusion Layer ◽  
Water Mixture ◽  
Dropwise Condensation ◽  
Heat Transfer Characteristics ◽  
Vapor Diffusion ◽  
Transfer Characteristics ◽  
Condensate Layer

In this paper, a model was developed to predict the heat transfer characteristics of Marangoni dropwise condensation. In accordance with the feature of Marangoni condensation, condensation was treated as dropwise condensation of mixture vapors. The condensation space was divided into two parts: the vapor diffusion layer and the condensate layer. For the condensate layer, the classical heat transfer calculation method of dropwise condensation was imitated to obtain the heat transfer characteristics. For the vapor diffusion layer, the heat transfer characteristics were achieved by solving the conservation equations. These heat transfer characteristics were coupled through the conjunct boundary, which was the vapor-liquid interface. The model was applied to the condensation of water-ethanol mixture vapors. A comparison with the existing experimental data showed that the developed model could basically reflect the influences of vapor-to-surface temperature difference, vapor concentration, vapor pressure, and vapor velocity on heat transfer characteristic of Marangoni condensation. Results showed that some differences existed between the calculation results and experimental results, but the prediction deviation of the model could be acceptable in the range of vapor-to-surface temperature difference where the condensation heat transfer coefficients reached peak values.

scholarly journals Study on Flow and Heat Transfer Characteristics of Supercritical Kerosene in a Round Tube

2020 ◽  
Vol 316 ◽  
pp. 03003
Author(s):  
Feng Gao ◽  
Qian Zhang ◽  
Hongyu Xiao ◽  
Fengli Chen ◽  
Xuefeng Xia
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Inlet Temperature ◽  
Wall Surface ◽  
Heat Transfer Characteristics ◽  
Navier Stokes Equation ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Wall Surface Temperature ◽  
Central Flow

The finite volume discrete solution of the Navier-Stokes equation and the RNG model of the turbulence model are used to numerically simulate the flow and heat transfer characteristics of supercritical kerosene in a circular tube. The results show that as the inlet mass flow increases, the wall surface temperature and the central flow oil temperature gradually decrease, and the pressure loss becomes larger. As the inlet temperature increases, the wall surface temperature and the central flow oil temperature both increase. When the heat flux density is constant, as the pressure increases, the deterioration of heat transfer will be weakened, and increasing the pressure can improve the effect of convection heat transfer.

Study on Electromagnetic Heating System of Heat Transfer Oil and Automatic Temperature Control Algorithm

2015 ◽  
Vol 727-728 ◽  
pp. 769-773
Author(s):  
Shun Wei Wu
Keyword(s):  
Heat Transfer ◽  
Temperature Control ◽  
Control Algorithm ◽  
Original System ◽  
Heating System ◽  
Electromagnetic Heating ◽  
Automatic Temperature Control ◽  
Intelligent Pid ◽  
Heavy Pollution ◽  
Heating Mode

There are some insufficient on the existing heating system of heat transfer oil,such as the heavy pollution, large consumption of electricity, waste of resources, and many hidden danger. through the adoption of automatic calculus intelligent PID temperature control algorithm and the electromagnetic heating mode, the shortage of the original system was improved, and the relevant error was analyzed, and then the overall composition of the system was designed. The the key technology and specific measures of system design were studied.

Boiling Heat Transfer Characteristics of Staggered-array Water Impinging Jets on Hot Steel Plate

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Sang Gun Lee ◽  
Jin Sub Kim ◽  
Dong Hwan Shin ◽  
Jungho Lee
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Temperature ◽  
Boiling Heat Transfer ◽  
Steel Plate ◽  
Nucleate Boiling ◽  
Impinging Jets ◽  
Heat Transfer Characteristics ◽  
Maximum Heat ◽  
Maximum Heat Flux

The effect of staggered-array water impinging jets on boiling heat transfer was investigated by a simultaneous measurement between boiling visualization and heat transfer characteristics. The boiling phenomena of staggered-array impinging jets on hot steel plate were visualized by 4K UHD video camera. The surface temperature and heat flux on hot steel plate was determined by solving 2-D inverse heat conduction problem, which was measured by the flat-plate heat flux gauge. The experiment was made at jet Reynolds number of Re = 5,000 and the jet-to-jet distance of staggered-array jets of S/Dn = 10. Complex flow interaction of staggered-array impinging jets exhibited hexagonal flow pattern like as honey-comb. The calculated surface heat transfer profiles show a good agreement with the corresponding boiling visualization. The peak of heat flux accords with the location which nucleate boiling is occurred at. In early stage, the positions of maximum heat flux locate at the stagnation point of each jet as the relatively low surface temperature is shown at their positions. At the elapsed time of 10 s, the flat shape of heat flux profile is formed in the hexagonal area where the interacting flow uniformly cools down the wetted surface. After that, the wetted area continuously enlarges with time and the maximum heat flux is observed at its peripheral. These results point out that the flow interaction of staggered-array jets effectively cools down the closer area around jets and also show an expansion of nucleate boiling and suppression of film boiling during water jet cooling on hot steel plate. [This work was supported by the KETEP grant funded by the Ministry of Trade, Industry & Energy, Korea (Grant No. 20142010102910).]

Study of Thermal Influence on Tubes Due to Sodium-Water Reactions in LMFBR Steam Generator

2004 ◽  
Author(s):  
Hirotsugu Hamada ◽  
Akikazu Kurihara ◽  
Masahiro Nishimura
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Steam Generator ◽  
Outer Surface ◽  
Single Phase ◽  
Tube Wall ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Transfer Characteristics ◽  
Thermal Influence

A study of thermal influence on heat-transfer tubes in sodium-water reactions is carried out to evaluate the tube rupture due to overheating in the water leak accident of an LMFBR steam generator (SG). By assuming the sodium-water reaction jet to be a two-phase flow that consists of sodium and hydrogen, the heat-transfer characteristics are examined and a simple model of effective heat-transfer coefficient (HTC) is proposed for the safety evaluation of the SG. Comparison of the model with experimental data leads to the following conclusions: An upper limit exists in the HTC between reaction jet and tube wall, and it is equivalent in approximation to the HTC of single-phase sodium flow. The HTC can be written in simple form as functions of the HTC of single-phase sodium flow, void fraction and temperatures of sodium, hydrogen and tube wall. Hydrogen provides negligible heating effect, so that the apparent HTC would decrease with increase of the hydrogen temperature that can readily surpass that of sodium. The outer-surface temperature of tube wall would not rise so high beyond the temperature of sodium that is excellent in heat-transfer characteristics, even if tube wall is exposed to the high-temperature hydrogen. The transient heat conduction analysis with the mean value of the data can appropriately evaluate the outer-surface temperature of tube wall by the metallographic observation, while the analysis with the maximum value can conservatively evaluate the tube wall temperature.

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