Flash Vessel Liquid Level Control via Hydrostatic Tower

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In high-pressure acid leach processes, the flash vessel's liquid level control is inadequate due to steam generation, leading to variable liquid levels and frequent damage to vapor and slurry outlet pipes and valves, especially in large-sized vessels handling strong acid slurries where visual inspection is impossible.

Innovation Solution

A hydrostatic tower with maximum and minimum liquid level sensors is used to accurately measure the liquid level, controlling the slurry outlet valve to maintain appropriate levels, preventing inflow of slurry into vapor outlets and vapor into slurry outlets, thus reducing equipment damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a sensor is directly attached to the flash vessel to measure liquid level, then the measurement is simple, but the liquid level becomes variable and inaccurate due to steam generation

Engineering Contradiction:
Improvemeasurement system complexityVSAvoidliquid level measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

A hydrostatic tower is introduced as an intermediary device between the flash vessel and the liquid level sensor. The tower provides a stable measurement environment isolated from steam generation, while still allowing accurate liquid level detection through hydrostatic pressure transmission from the flash vessel bottom.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the flash vessel is made large to handle strong acid slurries, then the processing capacity increases, but visual inspection becomes impossible and liquid level control becomes inadequate

Engineering Contradiction:
Improveslurry processing capacityVSAvoidliquid level detectability
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The hydrostatic tower serves as an external intermediary measurement system that allows accurate liquid level detection of large flash vessels without requiring direct access or visual inspection inside the vessel. The tower translates internal liquid level information into externally measurable hydrostatic pressure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Visual inspection and direct mechanical measurement methods are replaced with a hydrostatic pressure-based measurement system. This substitution enables accurate liquid level detection in large vessels where direct observation is impossible, using pressure transmission rather than visual or mechanical probes inside the vessel.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If liquid level control is inadequate, then the operation is simpler, but equipment damage occurs frequently

Engineering Contradiction:
Improveoperation simplicityVSAvoidequipment reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The hydrostatic tower provides continuous and accurate liquid level feedback to the control system. This feedback enables automatic adjustment of slurry inlet and outlet flows to maintain optimal liquid levels, preventing equipment damage while maintaining operational simplicity through automated control.

Inventive Principle:
Principle #23Feedback

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

The solution provides precise liquid level control, reducing the frequency of equipment failures and extending the operational lifespan of vapor and slurry outlet pipes and valves by maintaining stable liquid levels within the flash vessel.

Implementation Method 1

a hydrostatic tower whose lower part communicates with a liquid phase space within the flash vessel and whose upper part communicates with a gas phase space within the flash vessel

Methodology Applied
Scientific EffectHydrostatic pressure: Hydraulic Press

Implementation Method 2

reducing the temperature and pressure of the slurry after leach to the ordinary temperature and ordinary pressure by using a flash vessel

Methodology Applied
Scientific EffectFlash evaporation: Flash Evaporation

Implementation Method 3

the vapor generated by introduction of the slurry is discharged through the vapor outlet port

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2803739B1Flash vessel and method for operating same
Publication Date: 2018.03.14 SUMITOMO METAL MINING CO LTD
  • EP2803739B1 patent drawingFigure 1
  • EP2803739B1 patent drawingFigure 2
  • EP2803739B1 patent drawingFigure 3

AI summary

A hydrostatic tower 20 whose lower part communicates with a liquid phase space within a flash vessel 10, and whose upper part communicates with a gas phase space within the flash vessel 10 is provided. A rising liquid level within the hydrostatic tower 20 is detected by at least one maximum liquid level sensor 21 A provided at a position at the same level as a predetermined maximum liquid level within the liquid phase space. A dropping liquid level within the hydrostatic tower 20 is detected by at least one minimum liquid level sensor 21 B provided at a position at the same level as a predetermined minimum liquid level within the liquid phase space.