scholarly journals An Effective Package of Antioxidants for Avoiding Premature Failure in Polypropylene Random Copolymer Plastic Pipes under Hydrostatic Pressure and High Temperature

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2825
Author(s):  
Enrique Blázquez-Blázquez ◽  
Joaquín Lahoz ◽  
Ernesto Pérez ◽  
María L. Cerrada

Pipes of polypropylene random (PP-R) copolymers are the best choice for hot- and cold-water networks. Validation of a severe test, accomplishing the ISO 1167 standard, is mandatory to assess their service lifetime expectancy. This work evaluates the behavior shown by three commercial pipes, either the original ones (new pipes) or after being subjected to a hydrostatic pressure test at elevated temperature (aged pipes). Several features with relevance for the final performance have been examined: crystalline characteristics, phase transitions in crystalline regions, effect of high temperature and pressure on these transitions, and oxidation induction time. Moreover, the presence of inorganic fillers, and the content of different antioxidants together with their depletion, have also been analyzed. Films from the new pipes were also prepared for replication of the different environments in order to achieve a better and complete understanding of the phase transitions in the crystalline regions and of the consumption of antioxidants. Distinct environments surrounded the inner and outer parts of the pipes exposed to the failure aging test at 110 °C: hot water and warm dry air, respectively. These features play a key role in the loss of additives and in the subsequent initiation of degradation. Even if the crystalline characteristics are appropriate in the polymeric matrix, the success of a pipe lies in the homogeneous dispersion of components for avoiding damage at interfacial properties, and in a correct package of antioxidants used in its formulation.

2013 ◽  
Vol 457-458 ◽  
pp. 423-427
Author(s):  
Xiao Qing Li ◽  
Xiao Yan Liu

With the development of oilfield exploration, the performance of electric submersible pump (ESP) has been enhanced very fast. It requires testing techniques develop at the same time. The most outstanding question is the testing of high temperature and pressure ESP. A testing well was drilled in Daqing in 1992. It keeps the water liquid state on 150 centigrade by high pressure. This system can simulate operational mode 3000 meters under the ground. But many new ESPs have been produced these years. The quondam testing system couldnt meet the testing requirement. A new testing system is desiderated eagerly. This paper developed a high temperature and pressure ESP testing experimentation system. Hydraulic/thermodynamic analysis calculation has been carried on. Friction resistance from constant pressure point to the suction inlet of hot water pump and the ESP in heating-forced cycle and experimentation primary cycle are calculated respectively. Keeping the water liquid state on 180 centigrade, constant pressure value was fixed on 2.5 MPa. The heat load is calculated including the heat that the water in the system and the equipment need and the heat loss. In order to protect ESP from emanating too much heat to keep the temperature and pressure of the system steady, heat exchange system has been designed. Cold load and heat exchange square have been calculated. Friction resistance and the size of the cold water cistern have been calculated. These provide necessary academic foundation for the testing experimentation of high temperature and pressure ESP.


1987 ◽  
Vol 8 (5) ◽  
pp. 204-209 ◽  
Author(s):  
J.A. Smith ◽  
K.R. Neil ◽  
C.G. Davidson ◽  
R.W. Davidson

AbstractThe increasing cost of energy directed our attention to testing the feasibility of low temperature washing. Hospital laundries use formulated chemicals at high temperature wash waters of 66°C. Wash water effluents and fabric bacterial counts of heavily soiled linen were correlated with alkalinity and temperature measurements to investigate the bacterial killing action of hot and cold wash formulas. Terry towels were found to be contaminated with 107to 109organisms per 100 cm2at the beginning of the washing process. The most common gram-negative rods found wereKlebsiella, EnterobacterandSerratiaspecies. Staphylococci were the predominant gram-positives. Both cold and hot water washing including the bleach cycle reduced bacterial counts in fabric by 3 log10. Similarly, wash water cfu/mL declined 3 to 4 log10. A further 0.5 to 1.0 log10reduction was effected in the 93.3°C drying cycle. Low temperature wash formulas were comparable to high temperature laundry with respect to bacterial counts and species. Cold water formulas at 31.1°C offer an alternative method to reduce energy consumption and maintain bacteriological and esthetic linen quality.


2015 ◽  
Vol 17 (11) ◽  
pp. 5058-5068 ◽  
Author(s):  
Ekaterina Korotkova ◽  
Andrey Pranovich ◽  
Johan Wärnå ◽  
Tapio Salmi ◽  
Dmitry Yu. Murzin ◽  
...  

Lignin was successfully isolated from spruce wood with an accelerated solvent extractor using low concentration aqueous NaOH as an extraction solvent. The biorefinery concept was also applied.


1879 ◽  
Vol 28 (190-195) ◽  
pp. 461-463 ◽  

The experiments described in this paper were undertaken at the instance of Sir William Thomson and by a method devised by him. The liquid whose thermal conductivity is to be determined is heated from above, to avoid convection currents. Two methods of heating have been used. In one, a horizontal steam chamber is applied at the top of the water or other liquid; and, steam being continuously passed through the heating chamber, the surface of the liquid under experiment is kept at a very high temperature, and heat is conducted from above downwards. In the other method a large quantity of very hot water is deposited on the top of a mass of cold water, mixing being prevented by a simple contrivance; and the heat of this super­-incumbent layer is conducted downwards through the colder water below.


2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.


1989 ◽  
Vol 100 (1) ◽  
pp. 135-141 ◽  
Author(s):  
A. I. Baranov ◽  
V. P. Khiznichenko ◽  
L. A. Shuvalov

2011 ◽  
Vol 96 (2-3) ◽  
pp. 353-363 ◽  
Author(s):  
G. Iezzi ◽  
M. Tribaudino ◽  
G. D. Ventura ◽  
I. Margiolaki

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