Autoclave Steam Generator Merging for Heat Loss Reduction

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Solution Overview

Problem

Existing autoclaves face issues with inefficient sterilization due to heat dispersion, high energy consumption, large size, and slow processing times, leading to suboptimal sterilization quality and space constraints in medical-dental settings.

Innovation Solution

The autoclave design features a steam generator with heat conductors inside the sterilization chamber, a thermal insulation coating, and a recirculation system with hygroscopic volumes to maintain steam quality and efficiency, including a drainage system for condensate reutilization and a compact layout.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the steam generator is placed outside the sterilisation chamber, then the device structure is simpler, but heat dispersion causes steam cooling and condensate formation deteriorating sterilisation quality

Engineering Contradiction:
Improvedevice structureVSAvoidsterilisation quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The steam generator is merged with the sterilisation chamber by placing it inside the chamber. The generator comprises a housing with a heating element that directly contacts the sterilisation fluid, enabling steam generation at the point of use and eliminating heat loss in external ducts.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A thermal insulation coating is applied to the outer surface of the chamber to reduce heat loss to the surrounding environment. This intermediary layer maintains the thermal energy within the chamber, preventing excessive cooling of the steam.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the steam is heated well beyond the temperature needed for sterilisation, then steam quality is maintained despite heat dispersion, but energy consumption increases and localised overheating deteriorates chamber structure

Engineering Contradiction:
Improvesteam qualityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The heating element is positioned in direct contact with the sterilisation fluid within the steam generator housing, creating a localized high-temperature zone only where steam generation is needed. This eliminates the need to overheat the entire chamber while maintaining sufficient steam temperature.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The condensate that would normally represent heat loss and energy waste is redirected back to the steam generator and revaporised by the heating element. This converts the harmful effect of condensation into a beneficial recycling of thermal energy and sterilisation fluid.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Loss of substance

If an additional resistor is connected externally to the chamber to revaporise condensate, then sterilisation fluid is reused, but localised overheating at the resistor point deteriorates chamber structure

Engineering Contradiction:
Improvesterilisation fluid lossVSAvoidchamber structure
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The condensate revaporisation function is extracted from the external chamber structure and integrated into the internal steam generator. The heating element is contained within the generator housing, separating the heating function from the chamber structure and eliminating localized overheating damage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The steam generator housing acts as an intermediary structure that contains the heating element and directs its thermal energy specifically to the sterilisation fluid. This protects the chamber structure from direct contact with high-temperature heating elements while still enabling condensate revaporisation.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If the autoclave is designed with large dimensions, then all functional components can be accommodated, but the device occupies excessive space in limited dental practice environments

Engineering Contradiction:
Improvecomponent accommodationVSAvoiddevice volume
Core Design Contradiction:
Ease of manufactureVSVolume of moving object

Solution Approach 1:

The steam generator is nested within the sterilisation chamber, with the generator housing positioned inside the chamber volume. The heating element is nested within the generator housing, and the sterilisation fluid surrounds these components. This nested arrangement maximizes space utilization and minimizes the overall device footprint.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The steam generator serves multiple functions: it heats the sterilisation fluid, generates steam, and revaporises condensate. The sterilisation chamber simultaneously contains the instruments, the steam, and the steam generator. This multi-functionality reduces the need for separate components and reduces overall device volume.

Inventive Principle:
Principle #6Universality (Multi-functionality)

5Reliability

If the sterilisation process is extended to ensure complete sterilisation, then sterilisation quality improves, but processing time increases reducing productivity

Engineering Contradiction:
Improvesterilisation qualityVSAvoidsterilisation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The steam generator pre-heats the sterilisation fluid to the required temperature before sterilisation begins. This preliminary heating action ensures that when steam is introduced, the chamber is already at optimal temperature, reducing the time needed to achieve sterilisation conditions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heating element operates continuously during the sterilisation process, maintaining the sterilisation fluid at the required temperature throughout. This continuous heating action ensures consistent steam generation and eliminates temperature fluctuations that would extend processing time.

Inventive Principle:
Principle #20Continuity of useful action

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 configuration ensures high-quality, rapid sterilization with reduced energy consumption and compact dimensions, effectively addressing the limitations of prior autoclaves by maintaining steam quality and optimizing space usage.

Implementation Method 1

a steam generator positioned between the supply system and sterilisation chamber and suitable to vaporise the sterilisation fluid

Methodology Applied
Scientific EffectVaporisation: Evaporation

Implementation Method 2

The autoclave design features a steam generator with heat conductors inside the sterilization chamber, a thermal insulation coating

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

a recirculation system with hygroscopic volumes to maintain steam quality and efficiency

Methodology Applied
Scientific EffectHygroscopic absorption: Absorption (physical)

Data Source

PatentEP2968627B1autoclave
Publication Date: 2017.09.06 NAKANISHI INC
  • EP2968627B1 patent drawingFigure 1
  • EP2968627B1 patent drawingFigure 2~3

AI summary

An autoclave (1) is provided comprising a sterilisation chamber (20); a steam generator (40) comprising a heat conductor (41) housed in the sterilisation chamber (20) and comprising a vaporisation duct (41a) for the sterilisation fluid (1b) and connectors (43) suitable to connect the vaporisation duct (41a) and the sterilisation chamber (20) in a fluidic through connection: and a heater (42) suitable to heat the heat conductor (41) by vaporising the sterilisation fluid (41) in said vaporisation duct (41a).