Ammonia Reactor Start-Up Heater Vibration Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Internal start-up heaters in ammonia reactors are prone to mechanical stress and vibrations due to flow-induced forces, leading to deformation, damage, and potential short circuits, which compromises their reliability and service life, and poses challenges in maintenance and revamping without increasing the reactor's diameter.

Innovation Solution

The internal start-up heater features a unique arrangement of supporting plates with differently arranged beams that provide synergistic radial support to the elongated electric heating members, preventing displacement and vibration by direct contact, thus enhancing stability and reducing the risk of damage from flow-induced forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the heating members are spaced with large clearance to allow gas flow, then the gas flow cross-section is sufficient, but the heating members become highly sensitive to flow-induced vibrations and mechanical stress

Engineering Contradiction:

Improvegas flow rateVSAvoidheating member stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces supporting grids as intermediary structures between the heating members and the reactor wall. These grids provide mechanical support and reduce the clearance between heating members and the supporting structure, thereby reducing flow-induced vibrations while maintaining sufficient gas flow cross-section. The grids act as a mediator that stabilizes the heating members without significantly impeding gas flow.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the spatial arrangement parameters of the heating members by reducing the clearance between them and the supporting grids. This parameter change increases the structural stability and reduces vibration sensitivity while carefully maintaining the gas flow cross-section through optimized spacing design.

Inventive Principle:

Principle #35Parameter changes

2Volume of moving object

If the heating members are closely spaced to reduce reactor diameter, then the reactor volume is optimized, but the heating members become more susceptible to mechanical damage and short circuits

Engineering Contradiction:

Improvereactor diameterVSAvoidheating member durability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The supporting grids serve as intermediary structures that provide mechanical support to the closely spaced heating members. The grids reduce the direct exposure of heating members to flow-induced vibrations and prevent contact between adjacent heating members, thereby reducing the risk of mechanical damage and short circuits while maintaining the compact reactor diameter.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The supporting grids provide beforehand cushioning by creating a protective framework that absorbs and distributes mechanical stresses before they can reach the heating members. This preventive structure reduces the likelihood of mechanical damage and short circuits in the closely spaced heating member configuration.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If the heating members are made non-insulated to simplify construction, then the manufacturing is easier, but the risk of short circuits between heating members increases

Engineering Contradiction:

Improveconstruction simplicityVSAvoidelectrical insulation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The supporting grids act as electrical insulators between non-insulated heating members. By positioning the grids between adjacent heating members, they provide the necessary electrical insulation to prevent short circuits, allowing the use of simpler non-insulated heating member constructions while maintaining electrical safety.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional approach of insulating each heating member individually (mechanical insulation layer) with a supporting grid structure that provides electrical insulation through its positioning and material properties. This substitution simplifies the manufacturing of heating members while maintaining electrical insulation reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 effectively prevents destructive flow-induced vibrations, ensuring the heating members remain stable and functional, reducing the risk of overheating and damage, and allows for increased production rates without modifying the reactor's diameter or vessel, thereby improving the reliability and efficiency of ammonia synthesis.

Implementation Method 1

internal electric heater located inside the reactor itself... consisting of a mounting flange, with the necessary electrical connections, and a bundle of longitudinal heating members

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS8518330B2Start-up heater for ammonia reactors

Publication Date: 2013.08.27 CASALE SA

AI summary

An internal start-up heater (10) for an ammonia reactor (1), comprising longitudinal heating members (16) and a supporting structure for said heating members (16), the structure comprising plates (20A-20D) with parallel beams (22A-22D) in contact with said heating members (16), wherein the plates are arranged in plate sets formed by at least a first and a second plate having differently arranged supporting beams.