SU1006854A1 - Method of applying thermo-insulating coating on a pipe - Google Patents

Description

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4 The invention relates to the construction of pipelines, mainly from prefabricated pipes, and can be used when applying to the pipe a monolithic heat insulating foam coating. There is a known method of applying a heat insulating foam coating to a pipe installed in a detachable form or a shell with a concentric gap, by pouring a tube-form or pipe-shell from the end face of the reaction mixture of foam plastic into the annular space, and the reaction mixture of foam plastic spreading and foaming, filling em annular space and cures, forms a heat insulating foam coating t However, this method of applying a heat insulating coating does not allow to obtain a high quality coating when applied and on the tube length of more than 6 m, for applying heat tsisznnogo coating on the pipe length of 12 m along the length of the shell space is divided into 5 sections C-shells and fill the reaction mixture is carried out in each section separately. This increases the coating time and degrades its quality. Closest to the proposed technical solution is a method of applying a heat insulating foam coating to the pipe, which consists in uniformly distributing the polystyrene reaction mixture in the shell-tube or form-tube-pipe moving from one end to another mixing head on a long rod. The disadvantage of this method is that when switching from insulating a small-diameter pipe to insulating an increased-diameter pipe with the same coating thickness and active foam mixture, the small mixing head will not provide more increased performance, the quality of the thermal insulation coating will decrease, the use of two paired mixing heads will complicate the process of pouring the reaction mixture into the tube-form annulus; the size of the gap between the pipe and the form, equal to the thickness of the heat insulating coating, limits the range of diameters of the insulated pipes. The aim of the invention is to improve the quality of the heat insulating coating applied to pipes of increased diameters. This goal is achieved by the fact that according to the method of applying a heat insulating coating to a pipe, including inserting a mixing head into a concentric annular gap of a pipe-form, uniform distribution of the reaction mixture of the foam mixing head over the length of the mold during reverse, before introducing the mixing head of increased capacity into the annular the tube is eccentrically displaced relative to the mold, and at the end of the pouring and distribution of the reaction mixture the annular holes at the ends of the form, they are closed with flanges and the pipe is returned to its original coaxial position with respect to the form. All operations are carried out until the beginning of foaming of the reaction mixture of foam. PRI me R. The required quality of the thermal insulation coating made of polyurethane foam on a pipe with a diameter of 219 mm is provided by means of a mixing head with an increased capacity of 222 kg / min and a height of 85 mm. forming for- we, under the lower tubes and molds, get a gap of 100 mm, a mixing head of increased productivity is introduced into this gap, during the return stroke of the mixing head, which takes 10 seconds, the polyurethane foam reaction mixture is evenly distributed over the length of the mold, after removing the mixing head From the annular space, the annular eccentric opening between the pipe and the rear is closed with a flange and the pipe is lowered to its original coaxial position with respect to the shape, the lowering of the pipe is performed before the beginning of foaming Vanilla the reaction mixture of polyurethane foam at the other end of the form. The outer diameter of the flanges is larger than the diameter of the mold; the flanges are tightened; with its plane to the face of the seal, slide along the ends of the mold when raising and lowering the pipe and compact these compounds from overflow of the reaction mixture of polyurethane foam. The reaction mixture of polyurethane foam, foaming, rises on concentrate 100685

annular gap annular simple-method of applying on the tube of zagranzhstva, fills it and forms the insulated diameter of the heat-insulating

the surface of a pipe with a diameter of 219 mmcoating improves the quality

heat insulation coating of the same heat insulation coating of foam thickness and with a given formation density and expanding the range of diameters 80 kg / mg of insulated pipes.

Claims (1)

METHOD FOR APPLYING A HEAT-INSULATING COATING TO A PIPE, including introducing a mixing head into the concentric gap of the pipe-to-tube annular space, filling and uniform distribution of the foam reaction mixture with a mixing head along the length of the mold during the reverse stroke, characterized in that, in order to improve the quality of the heat-insulating coating, applied to pipes of increased diameters, before introducing a mixing head of increased productivity into the annulus, the pipe is eccentrically displaced form, and upon completion of pouring and distribution of the reaction mixture, the annular holes in the ends of the mold are closed with flanges and the pipe is returned to its original position coaxial with respect to the mold. 1 10068 ^ 2