Waste heat recovering and utilizing system and method of plastic pipe production line

Abstract

The invention discloses a waste heat recovering and utilizing system and method of a plastic pipe production line. The waste heat recovering and utilizing system comprises a heat recovering device arranged at an extrusion molding core mould, wherein the heat recovering device is connected with a raw material preheating bin; the heat recovering device comprises a heat recovering hole connected in from the core mould and connected with the center of an extruded plastic pipe. The waste heat recovering and utilizing method disclosed by the invention comprises the following steps: obtaining the temperature of the center of the plastic pipe of the extrusion core mould; sucking the heat by adopting a negative pressure fan; conveying the heat to the raw material preheating bin and other heat utilizing occasions; detecting the temperature in the core mould in real time, regulating a working parameter of the negative pressure fan; and detecting the temperature in the raw material preheating bin in real time so as to regulate inlet air heat. According to the waste heat recovering and utilizing system and method, high-temperature air is sucked from the interior of the plastic pipe and the sucked heat is used in production. Because the inner wall of the plastic pipe is effectively cooled, the difference of the temperatures inside and outside the plastic pipe is balanced, and no cracks are easily formed. Because the cooling speed of the plastic pipe is relatively high, the delivery speed of the pipe is high, and the yield is increased. Meanwhile, heat energy is recycled, so that the energy consumption is reduced.

Description

technical field [0001] The invention relates to a waste heat recovery and utilization system and method on a plastic pipe production line. Background technique [0002] The application range of plastic pipes is very wide, and the most important applications at present are mainly water supply and gas supply. The pipes including the urban pipe network are mainly plastic pipes, and the annual output of plastic pipes in the country is very large. [0003] The industrial assembly line production process of plastic pipes is as follows. The plastic pellets are preheated in the raw material bin, and the preheating temperature is about 80 degrees to discharge the moisture that may be entrained in the plastic pellets. The preheated plastic particles are put into the mold, melted by high temperature, and continuously extruded through the core mold by the screw, and the plastic tube is formed. The formed plastic tube immediately enters the vacuum box for cold water spraying to cool d...

AI Technical Summary

Problems solved by technology

[0006] 2. The inner wall of the plastic pipe has not been cooled, the temperature of the inner wall is high, and the cooling and shaping of the pipe body is slow, resulting in poor cooling effect. The plastic pipe that fails to achieve the cooling effect cannot be offline. Only by extending the cooling time and delaying the offline time to achieve required cooling effect

The output speed of the production line is slow, and the output efficiency per unit time is low.

[0007] 3. The residual temperature of the plastic pipe after it comes off the line penetrates from the inside to the outside, forming residual stress. The pipe is easily deformed under the residual stress, which affects the pipe, ovality and straightness of the pipe.

[0008] 4. The core mold is composed of a sleeve and a core rod inside the sleeve. The sleeve completes the external molding of the plastic tube, and the core rod completes the inner wall of the plastic tube. Due to the high temperature inside the core mold, the plastic attached to the core rod is easy to precipitate Small molecular materials form deposits, which are granular. After the plastic tube is extruded from the core rod, the granular deposits will form scratches on the inner wall of the plastic tube, affecting the smoothness of the inner surface of the plastic tube.

[0009] 5. A large amount of heat is discharged in the plastic pipe, resulting in waste of heat energy and affecting the environment at the same time

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