Multi-Zone Sleeve Heating for Uniform Pipe Shrink Application

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Solution Overview

Problem

Conventional methods for heating heat-shrinkable sleeves on pipes are inefficient due to inhomogeneous heating and require manual movement of heating apparatus, which slows down the production process and can lead to uneven heating and air entrapment.

Innovation Solution

A heat-delivery apparatus with multiple individually controlled heater devices along the axial direction that generates heat to different regions of the sleeve in a controlled manner without axial movement, ensuring even heating and progressive shrinking by varying the heat output of each device and using infrared heaters to efficiently heat the sleeve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual torch heating is used, then the heating process can be performed with simple equipment, but the heating becomes inhomogeneous and production speed decreases

Engineering Contradiction:

Improveheating uniformityVSAvoidproduction speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The heating apparatus is divided into multiple independently controllable heater zones (first, second, and third heater devices) positioned at different locations along the sleeve. Each zone can be controlled separately to deliver heat uniformly across the entire sleeve surface simultaneously, eliminating the inhomogeneous heating problem while maintaining high production speed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple heater devices are combined into a single integrated apparatus that heats the entire sleeve at once. This merging of heating functions into one stationary unit replaces the sequential manual torch approach, achieving both uniform heating and high productivity through simultaneous multi-zone heating.

Inventive Principle:

Principle #5Merging (Combining)

2Manufacturing precision

If manual movement of heating apparatus is required, then the equipment structure can be simpler, but the heating process becomes slower and less consistent

Engineering Contradiction:

Improveheating consistencyVSAvoidheating time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The heater devices are pre-positioned in fixed locations along the sleeve path before the heating process begins. This preliminary arrangement of multiple heating zones ensures that all necessary heating positions are ready simultaneously, eliminating the need for movement during heating and achieving consistent, time-efficient heating.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of moving a single heater along the sleeve, the invention inverts the approach by having multiple stationary heaters positioned at different locations. The heat source remains fixed while the multi-zone configuration provides the necessary heating coverage, reversing the conventional moving-heater paradigm.

Inventive Principle:

Principle #13The other way round (Inversion)

3Adaptability or versatility

If a single ring of heater elements is used, then the apparatus structure is simpler, but the heating coverage and control capability are limited

Engineering Contradiction:

Improveheating control capabilityVSAvoidapparatus structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single ring heater is segmented into multiple independent heater devices positioned at different locations along the sleeve. Each segment can be controlled independently, providing superior heating control capability and adaptability to different heating requirements, while the modular structure manages the complexity through standardized components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The heating apparatus transitions from a single-dimensional ring configuration to a multi-dimensional arrangement with heater devices distributed along the axial length of the sleeve. This dimensional expansion provides better heating control and coverage without excessive complexity through systematic spatial distribution.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method significantly reduces the time needed to heat-shrink the sleeve, ensures even heating, and prevents air entrapment, thereby increasing production speed and quality by maintaining precise control over the heating process.

Implementation Method 1

The apparatus includes a first, second, and third heater devices... applying heat to all regions of the heat-shrinkable sleeve via the heat-delivery apparatus... using infrared heaters to efficiently heat the sleeve

Methodology Applied

Scientific EffectInfrared radiation: Infrared Radiation

Data Source

PatentEP3698943B1Apparatus and method for heating heat-shrinkable pipe sleeves

Publication Date: 2023.04.19 SAIPEM SPA

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AI summary

A method of applying a heat-shrinkable sleeve to a portion of a pipe (2) is disclosed. The method includes arranging a heat-shrinkable sleeve around a portion of the pipe and arranging a heat-delivery apparatus (12) around the pipe (2) in the region of the sleeve. The heat-delivery apparatus (12) includes at least three heater devices (22) arranged at different positions along the axis of the pipe. The method includes operating the first, second and third heater devices to apply heat to the heat-shrinkable sleeve, and during heat-shrinking of the sleeve, the method includes the step of sensing the temperature of the sleeve or in the region of the sleeve and then using the temperature so sensed to control the driving of at least one of the heater devices (22).