RU64133U1 - DEVICE FOR PRODUCING POLYMER PIPES - Google Patents

Abstract

The utility model relates to the processing of polymers and the manufacture of pipes from them. The molten billet of the pipe extruded from the extrusion head is calibrated by the outer diameter and cooled from the outside and inside. Cooling from the inside of the pipe is carried out by blowing air from the free end of the pipe towards the direction of extrusion. Air is removed from the treatment zone through the pipe using an intake fan. An additional cooling effect can be obtained by supplying water dust to the air blown through the pipe cavity. The means of internal cooling of the pipe is made in the form of a thin-walled pipe located in the central channel of the extrusion head, connected at one end to the suction pipe of the fan, the other end of which extends beyond the front end of the extrusion head. To carry out additional supply of water dust to the purged air, a tube is installed inside the cooling pipe, which protrudes beyond the front end of the cooling pipe, having a nozzle at the free end for spraying water. The technical effect is to increase the cooling efficiency without the formation of reverse condensation and to ensure the immediate removal of the generated vapor from the pipe cavity.

Description

The utility model relates to the processing of polymers and the manufacture of pipes from them.

Extrusion is the most productive and widespread processing process applicable to almost all known thermoplastics and their compositions. The processing of thermoplastic into a product from the point of view of physics consists in its heating and cooling.

To cool the pipes, irrigation baths with intensive and uniform watering of the pipe are used. However, this type of cooling requires large production areas. The maximum length of baths that the pipe manufacturer can afford is 50 m, and the vacuum length cannot be less than 24 m. The intensification of the pipe cooling process through the use of additional internal cooling of the pipe cavity can significantly increase productivity in their production.

Internal cooling is usually carried out by introducing into the pipe cavity any evaporating liquid heat having a high value of the heat of vaporization, for example, sprayed water, liquefied carbon dioxide and liquid nitrogen. Carbon dioxide and nitrogen, unlike water, evaporate irreversibly, however, their heat of vaporization is an order of magnitude lower than the heat of vaporization of water, and a huge amount of liquefied gas is required for effective cooling.

Water needs to be sprayed with a much smaller amount, however, the generated steam should be immediately removed from the internal cavity of the pipe, otherwise, when the condensation is back condensed, the heat removed will be returned to the pipe at later stages of cooling.

A known method of manufacturing a large diameter plastic pipe and a tool for its implementation, disclosed in SU 1823818 A3,

06/23/1993 / 1 /. When implementing the method, external cooling and internal cooling of the pipe are applied by supplying a cooling medium through a pipe mounted along the axis of the mandrel used to form the inner cavity of the pipe billet. At the end of the mandrel is made a suction hole for the cooling medium.

The closest analogue of the proposed device can be considered the device disclosed in US 5422063 A1, 06.06.1995 / 2 /. According to / 2 /, extruded from the extrusion head of the molten billet pipe, calibrate it to the outer diameter and cooling from the outer and inner sides. Internal cooling is carried out by spraying water using nozzles.

The disadvantage of technical solutions / 1 / and / 2 / is that the generated steam is transferred forward during the process, where the pipe is cold, where it condenses again, returning the previously selected heat (reverse condensation occurs), which practically destroys the entire effect of internal cooling, leading to reduce the efficiency of the process and the need to use additional tools to remove condensate from the treatment area.

The objective of the proposed utility model is to eliminate these disadvantages. The technical effect obtained in solving this problem is to increase the cooling efficiency without the formation of reverse condensation and to ensure the immediate removal of the generated vapor from the pipe cavity.

The technical result is achieved in that in a device for producing a polymer pipe by extrusion, containing an extrusion head and means for external and internal cooling of the pipe, the means of internal cooling of the pipe are made in the form of a thin-walled pipe located in the central channel of the extrusion head, connected at one end to a fan suction pipe , the other end of which extends beyond the front end of the extrusion head.

To carry out additional supply of water dust to the purged air, a tube is installed inside the cooling pipe, which protrudes beyond the front end of the cooling pipe, having a nozzle at the free end for spraying water.

Figure 1 schematically shows a device that provides internal cooling during the manufacture of the pipe.

The extrusion head 1 has a central channel 2 with a diameter of 150-200 mm, in which a thin-walled tubular element 3 is installed, the free end of which extends beyond the front end of the extrusion head 1, depending on the size of the pipe, by 0.2-1.0 m, and the other end is connected to the suction pipe of a high-performance industrial fan (not shown). A tube 4 is passed through element 3, connected at one end to a means for supplying water, having a nozzle 5 at its other end for spraying the supplied water. The tube 4 protrudes at a distance, respectively, of 0.5-4.0 m from the front end of the extrusion head.

The operation of the device is as follows. From the extrusion head 1, a molten pipe preform 6 is continuously extruded, which is calibrated in the usual way by the outer diameter and cooled from the outside. By means of a suction fan located in front of the extrusion head 1, air is continuously driven through the inner cavity of the pipe, which is sucked from the front end of the pipe, blown towards the direction of extrusion, and discharged through a thin-walled tubular element 3 connected to the suction pipe of the fan.

When pumping through the cavity of the pipe, the air, having heated, takes on up to 20% of the heat stored in the molten billet 6 of the pipe.

If water dust is added to the air using nozzle 5, which when in contact with the hot inner surface of the pipe turns into steam, then the amount of heat removed from the inner

pipe surface, will reach 40-50%. Since the air flow moving, for example, in the manufacture of a pipe with a diameter of 630 mm at a speed of about 2 m / s, will carry the steam back to the hotter zone, there will be no reverse condensation, and superheated steam will be removed outside the process using the same fan through the suction pipe.

Thus, the proposed device ensures the achievement of the specified technical result of increasing the efficiency and productivity of the process.

Claims (2)

1. A device for the manufacture of a polymer pipe containing an extrusion head and means of external and internal cooling of the pipe, characterized in that the means of internal cooling of the pipe is made in the form of a thin-walled tubular element placed in the Central channel of the extrusion head, connected at one end to the suction pipe of the fan, with placing its other end protruding beyond the front end of the extrusion head. 2. The device according to claim 1, characterized in that inside the tubular element there is additionally a tube protruding beyond the free end of the tubular element having a nozzle for spraying water at the free end.