Thermal Feedback Water Temperature Control for Safety Showers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for providing tepid water in safety shower systems lack rapid temperature control and fail to meet industry standards for temperature range and response time, often requiring external power sources and experiencing overtemperature issues.
Innovation Solution
An automated water temperature control system using steam and water, with feedback control valves and thermal actuators to regulate steam flow and mixing, ensuring tepid water delivery within a narrow temperature range without electricity, and featuring self-regulation to prevent overtemperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If downstream temperature sensor activates to send cold water back to steam line, then overtemperature condition is prevented, but response time is delayed and output temperature becomes unsteady
Solution Approach 1:
The patent applies preliminary action by using an upstream temperature sensor that detects temperature changes before they reach the downstream output. This allows the feedback controller to adjust steam flow proactively before overtemperature conditions occur at the output, eliminating the delayed response inherent in downstream sensing systems.
Solution Approach 2:
The patent implements feedback control by continuously monitoring temperature at the upstream location and automatically adjusting the steam control valve through a feedback controller. This closed-loop system responds immediately to temperature variations, maintaining steady output temperature while preventing overtemperature conditions.
2Manufacturing precision
If automated control system with rapid feedback is implemented, then temperature control precision is improved, but system complexity increases
Solution Approach 1:
The patent replaces complex electronic control systems with a simpler thermally-driven feedback mechanism. The feedback controller uses thermal expansion principles to actuate the steam control valve, eliminating the need for external electricity while maintaining precise temperature control through passive thermal sensing and actuation.
Solution Approach 2:
The system achieves self-regulation by using the thermal energy present in the water and steam themselves for sensing and actuation. The feedback controller and thermal actuators operate autonomously using only the thermal properties of the process fluids, requiring no external power source while maintaining precise temperature control.
3Extent of automation
If external power source such as electricity is used, then control functionality is enabled, but system requires external power and reduces reliability
Solution Approach 1:
The patent makes the control system self-sufficient by using the thermal energy already present in the water and steam for all sensing and actuation functions. The upstream temperature sensor detects temperature changes thermally, and the feedback controller actuates the steam valve using thermal expansion, eliminating all dependencies on external electricity or power sources.
Solution Approach 2:
The patent uses pneumatic and hydraulic principles by employing thermal expansion of gases or liquids within the feedback controller to actuate the steam control valve. This thermal-pneumatic actuation mechanism replaces electric motors or solenoids, enabling automated control without external power while maintaining reliability through inherent thermal energy utilization.
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 system provides tepid water at varying flow rates within precise temperature limits, ensuring user safety by rapidly adjusting to maintain desired temperatures and preventing overtemperature conditions, all while operating independently of external power sources.
Implementation Method 1
a first mixing valve controlled by a first thermal actuator that combines a heated water stream and a second water supply path
Implementation Method 2
delivering steam to a heat exchanger to heat a first water supply path to produce heated water
Implementation Method 3
a first mixing valve controlled by a first thermal actuator that combines a heated water stream and a second water supply path to produce a tempered water stream
Implementation Method 4
a second feedback controller that controls the second feedback control valve to open steam flow when water flow is sensed and close steam flow when an overtemperature condition is sensed
Data Source
AI summary
A system of thermally activated feedback control valves and thermally activated sensors to provide heated fluid within a desired temperature range which operates consistently at high and low flow rates, suitable for control of combination safety shower and eyewash stations.