Medical Washer Filling Control to Prevent Pump Cavitation
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Solution Overview
Problem
Conventional medical washers/disinfectors consume excessive water, energy, and detergent due to their fixed dimensions, which are designed for the largest load, leading to inefficiencies when processing smaller or less soiled loads, resulting in higher water pressure and flow than necessary.
Innovation Solution
A method that adjusts pump speed based on load size and soiling level, associating higher pump speeds with higher filling levels and lower pump speeds with lower levels, allowing for controlled filling to optimize water and detergent usage, and using two circulation pumps to manage liquid levels effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the medical washer/disinfector is dimensioned for the largest load, then it can handle all load sizes, but water consumption and energy usage increase excessively for smaller loads
Solution Approach 1:
The patent applies dynamics by making the pump speed variable rather than fixed. The circulation pump speed is dynamically adjusted based on the actual load size and soiling level detected in the washing chamber. This allows the system to adapt its water circulation rate to match the actual cleaning needs, preventing excessive water consumption and energy usage that would occur with a fixed high-speed pump operation designed for maximum load capacity.
Solution Approach 2:
The patent changes the operational parameters of the washing system by adjusting pump speed based on load characteristics. Different pump speeds are selected according to the detected load size and soiling level, which directly controls the water flow rate and pressure. This parameter adjustment enables the system to optimize resource consumption for each specific washing task rather than operating at constant maximum capacity.
2Productivity
If higher pump speed is used, then cleaning effectiveness increases, but water level drops and cavitation may occur
Solution Approach 1:
The patent implements feedback control by continuously monitoring the liquid level in the washing chamber and using this information to adjust the pump speed. When the liquid level drops due to high pump operation, the system detects this change and reduces pump speed accordingly to prevent cavitation. This closed-loop feedback mechanism ensures that the pump operates within safe parameters while maintaining effective cleaning performance.
Solution Approach 2:
The system dynamically adjusts pump speed based on real-time liquid level conditions. Rather than operating at a fixed high speed, the pump speed varies continuously to match the actual water level in the chamber, allowing the system to maintain high cleaning effectiveness when water is abundant while preventing cavitation when water level drops.
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 approach reduces water and detergent consumption while maintaining effective cleaning, providing an environmentally friendly and energy-saving solution by matching cleaning effort with load requirements and preventing cavitation.
Implementation Method 1
a circulation pump for circulating a liquid to and from the washing chamber
Implementation Method 2
By increasing the pump speed in a controlled manner based on the rising liquid level (rather than immediately starting with the desired pump speed), you can avoid cavitation effects and pressure strokes
Data Source
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AI summary
The invention relates to method of filling a medical washer/disinfector. A desired pump speed of a circulation pump is determined. A predefined filling level associated with the desired pump speed is identified. Liquid is fed into a washing chamber while the circulation pump is running at less than said desired pump speed. While the liquid is continued to be fed so that the liquid level rises, the pump speed is increased based on the rising liquid level until said desired pump speed is reached. When the pump is running at said desired pump speed, it is detected when the liquid has been filled to the predefined filling level, and upon such detection the feeding of the liquid into the washing chamber is interrupted. Then invention also relates to a method of operating a medical washer/disinfector, a control unit and a medical washer/disinfector.