reboiler

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In large-sized reboilers where liquid is supplied from the lower part and vaporized gas is discharged from the upper part, the gravity of the vaporized gas causes it to stay near the upper portion, hindering gas recovery and reducing efficiency.

Innovation Solution

The reboiler design incorporates a heat transfer tube group arranged with voids between the inner wall and the tubes, or within the tubes themselves, to separate vapor from liquid and enhance flow rates, preventing vapor from staying and improving heat transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple small-sized reboilers are combined into one large-sized reboiler to save space and reduce plant cost, then space utilization improves and plant cost decreases, but the vaporized gas tends to stay near the upper portion due to gravity, forming a gas-form lid that hinders gas recovery

Engineering Contradiction:
Improvespace utilizationVSAvoidgas recovery efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The reboiler vessel is divided into multiple functional zones using internal structures such as vapor disengagement chambers and liquid redistributors. This segmentation prevents vapor from forming a continuous lid across the entire vessel cross-section, allowing vapor to be efficiently separated and recovered while maintaining the space-saving benefit of a large-sized single vessel.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces vertical zoning within the vessel, creating distinct regions for heating, vapor disengagement, and liquid redistribution along the vertical dimension. This dimensional approach allows vapor to rise and be captured in upper zones while liquid continues to circulate in lower zones, preventing vapor stagnation and maintaining high gas recovery efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If liquid is supplied from the lower part and vaporized gas is discharged from the upper part, then the heating process is simplified, but the gravity of the vaporized gas causes it to stay near the upper portion, serving as a gas-form lid and hindering gas recovery

Engineering Contradiction:
Improveheating process complexityVSAvoidgas recovery efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

Vapor disengagement chambers and internal baffles are introduced as intermediary structures between the heating zone and the vapor discharge point. These intermediaries capture and redirect vapor flow, preventing it from forming a stagnant lid near the upper portion while maintaining the simple bottom-to-top heating configuration.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If a large-sized reboiler is used to combine multiple small-sized reboilers, then space saving and reduction in plant cost are achieved, but vapor recovery becomes difficult due to vapor staying near the upper portion

Engineering Contradiction:
Improveplant costVSAvoidvapor recovery efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The large-sized reboiler incorporates segmented internal structures including vapor disengagement chambers and liquid redistributors that divide the vessel into functional zones. This segmentation enables effective vapor recovery throughout the vessel volume while maintaining the cost-saving advantage of a single large vessel rather than multiple small ones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the reboiler are given different functional qualities: the lower portion is optimized for heating and liquid circulation, while the upper portion incorporates vapor disengagement chambers optimized for vapor capture. This local differentiation ensures high vapor recovery efficiency across the entire large-sized vessel.

Inventive Principle:
Principle #3Local quality

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 design prevents vapor from staying near the top, allowing for improved vapor recovery and heat transfer efficiency, achieving space savings and reduced plant costs.

Implementation Method 1

a heat transfer tube group (3) in a vessel (2) into which a liquid is supplied through lower inlets (6)

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the vaporized gas is discharged from upper outlets (7)

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 3

the gravity of the vaporized gas cannot be ignored so that the gas stays near an upper portion in a vessel

Methodology Applied
Scientific EffectGravity separation: Gravitation

Data Source

PatentEP2693147B1reboiler
Publication Date: 2019.11.13 MITSUBISHI HEAVY IND ENG LTD
  • EP2693147B1 patent drawingFigure 1~2
  • EP2693147B1 patent drawingFigure 3~4
  • EP2693147B1 patent drawingFigure 5(a)~6(b)

AI summary

There is provided a large-sized reboiler that can achieve space saving and reduction in plant cost. Specifically, there is provided a large-sized reboiler comprising a vessel of which a liquid is supplied from a lower part and a vaporized gas is discharged from an upper part; and a heat transfer tube group arranged in such a manner that a void penetrating in the up-and-down direction is formed in the vessel, wherein a maximum length of a cross-section of a flow path for the liquid exceeds 2m, and the void occupies 5 to 10% of an area of the cross-section of the flow path.