Determination of technological parameters of preheating of the polypropylene pipes for welding into the socket at low temperatures
DOI: 10.21047/1606-4313-2016-15-2-54-59
UDC 621.791.461: 66.046.1
Starostin N. P. , Vasil’eva M. A. , Botvin G. V.
Abstract
The mathematical model of a thermal process for the development of socket welding technology at temperatures below standard is offered. The heating stage of the welded ends of polypropylene pipe and fitting by means of special replaceable nozzles for subsequent welding at low temperatures is considered. Thermal process is simulated in the polypropylene pipe contacting to a replaceable nozzle at the base of which the constant temperature is kept by a heating plate of a definite temperature. Calculations have shown that heating plate temperature increase from 20 оСto 35 оСresults in twofold reduction of heating duration including the duration of cooling for equalization of temperatures. Computational experiments show that the temperature distribution in the wall of the hot-water pipe with diameter of 110 mm is close to the uniformed one from allowable welding range and is obtained by heating of an additional welding apparatus with replaceable nozzles, the apparatus heating plate having temperature of 35 оC. At low temperatures it is enough to maintain a heating plate temperature of 20 оC for heating the pipes of cold water supply. The offered method can be used for determination of technological parameters of preheating (the duration of heating and cooling) for polypropylene pipes and fittings of hot and cold water supply of various diameters at low ambient temperatures.
Keywords: polypropylene pipe, temperature, mathematical model, calculation, heating, cooling.
UDC 621.791.461: 66.046.1
Determination of technological parameters of preheating of the polypropylene pipes for welding into the socket at low temperatures
Abstract
The mathematical model of a thermal process for the development of socket welding technology at temperatures below standard is offered. The heating stage of the welded ends of polypropylene pipe and fitting by means of special replaceable nozzles for subsequent welding at low temperatures is considered. Thermal process is simulated in the polypropylene pipe contacting to a replaceable nozzle at the base of which the constant temperature is kept by a heating plate of a definite temperature. Calculations have shown that heating plate temperature increase from 20 оСto 35 оСresults in twofold reduction of heating duration including the duration of cooling for equalization of temperatures. Computational experiments show that the temperature distribution in the wall of the hot-water pipe with diameter of 110 mm is close to the uniformed one from allowable welding range and is obtained by heating of an additional welding apparatus with replaceable nozzles, the apparatus heating plate having temperature of 35 оC. At low temperatures it is enough to maintain a heating plate temperature of 20 оC for heating the pipes of cold water supply. The offered method can be used for determination of technological parameters of preheating (the duration of heating and cooling) for polypropylene pipes and fittings of hot and cold water supply of various diameters at low ambient temperatures.
Keywords: polypropylene pipe, temperature, mathematical model, calculation, heating, cooling.
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