Ice Maker Sump Fill Control for Consistent Batch Volume
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ice makers face challenges in ensuring consistent ice batch volume due to variations in water supply pressure and splashing, leading to inconsistent ice formation and potential failure in ice harvesting.
Innovation Solution
The ice maker employs a control system that executes a pulsed fill routine to consistently fill the sump to a predefined freeze routine starting level, and a differential freeze routine that circulates water until a predefined differential water level decrease is achieved, thereby ensuring consistent ice batch production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If water is supplied continuously to the sump, then the sump can be filled quickly, but water supply pressure variations cause inconsistent water levels and ice batch volume
Solution Approach 1:
The patent applies periodic action by using a pulsed fill routine that opens and closes the water inlet valve at predetermined intervals during the fill routine. This pulsing action divides continuous water supply into discrete increments, allowing the water level to be filled in controlled steps rather than continuously. This resolves the contradiction by maintaining fill productivity while achieving consistent water levels despite pressure variations, as each pulse adds a measurable amount of water that can be precisely controlled.
2Ease of operation
If water inlet valve remains open during fill, then filling is simple and fast, but splashing and pressure variations lead to overshot water levels
Solution Approach 1:
The water inlet valve is pulsed open and closed at predetermined intervals during the fill routine, transforming a simple continuous operation into a controlled periodic process. This maintains ease of operation through automated control while achieving precise water level measurement and avoidance of overshot, as the pulsing allows the system to respond to water level feedback between pulses.
Solution Approach 2:
The system uses a water level sensor to provide feedback on the actual water level in the sump during the pulsed fill routine. The controller receives this feedback and adjusts the pulsing of the water inlet valve accordingly, allowing the system to achieve precise water level control while maintaining simple automated operation. The feedback mechanism enables the system to correct for splashing and pressure variations in real-time.
3Device complexity
If freeze routine uses fixed water level threshold, then control is simple, but variations in initial water level cause inconsistent ice formation
Solution Approach 1:
The patent applies preliminary action by ensuring the sump is filled to a precise starting water level using the pulsed fill routine before the freeze routine begins. This preliminary precise filling establishes a consistent initial condition for each freeze cycle, which compensates for the simplicity of using a fixed water level threshold during freezing. The preliminary action of precise filling ensures that even with simple fixed-threshold control during freezing, the ice formation consistency is maintained because all cycles start from the same known water level.
Solution Approach 2:
The system replaces complex adaptive control during the freeze routine with a simpler fixed water level threshold, relying instead on the preliminary precise filling action to ensure consistency. This substitution of a complex continuous control system with a simpler fixed threshold, made viable by the pre-established precise initial conditions, reduces device complexity while maintaining ice formation consistency.
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 proposed solution ensures consistent ice batch volume by mitigating the effects of water supply pressure variations and splashing, leading to improved reliability and efficiency in ice production.
Implementation Method 1
A refrigeration system is configured to cool the ice formation device for forming at least some of the water circulated by the water system into ice
Implementation Method 2
a water level sensor configured to output a signal representative of water level in the sump to the controller
Data Source
AI summary
A batch ice maker can execute a pulsed fill routine in which a control system pulses water from a water supply into the sump until the sump reaches a predefined freeze routine starting level. Pulsing may begin after continuously filling the sump to a fill-approach level. A batch ice maker can execute a differential freeze routine in which the control system circulates water from a sump to an ice formation device until water level decreases by a predefined differential amount from a high control water level based on the water level in the sump at a point in time after the sump was filled to a freeze routine starting level. The high control water level can be set based on water level in the sump when sump water temperature reaches a predefined pre-chill temperature. The predefined pre-chill temperature can be associated with a switchover from sensible cooling to latent cooling.