Adjustable Fill Level Sensor for Wastewater Pumps

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Solution Overview

Problem

Existing sewage lifting stations lack the ability to easily adjust the water level at which the pump is activated, requiring replacement of the fill level sensor to change starting levels, which is inconvenient and inefficient.

Innovation Solution

A sewage lifting plant with a fill level sensor featuring a movable pressure surface and a selection device that allows for adjustable counterforces, enabling the pump to be switched on at different liquid levels without replacing the sensor, using a force-generating means like a compression spring to alter the activation level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed fill level sensor is used to detect water level, then the pump can be switched on at a predetermined level, but the starting level cannot be adjusted without replacing the sensor

Engineering Contradiction:
Improveadjustability of pump activation levelVSAvoidcomplexity of level sensor mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by introducing a force-generating means (spring) that can be adjusted to different compression states, thereby changing the force parameter acting on the pressure surface. This allows the same sensor mechanism to detect different water levels by simply adjusting the spring compression, without modifying the sensor structure or replacing it.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by making the force-generating means adjustable rather than fixed. The spring compression can be dynamically modified through a setting device, allowing the system to adapt to different operational requirements. This transforms a static level detection system into a dynamic one where the activation threshold can be changed without hardware replacement.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the force-generating means is adjusted to change the counterforce, then different liquid levels can be selected for pump activation, but the device requires additional adjustment mechanisms

Engineering Contradiction:
Improvenumber of selectable starting levelsVSAvoidease of adjusting activation level
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent replaces complex mechanical adjustment mechanisms with a simplified spring compression system. Instead of requiring mechanical repositioning of the pressure surface or switch components, the system uses spring force adjustment to achieve the same effect. This substitution simplifies the adjustment process while maintaining multiple selectable levels.

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

Solution Approach 2:

The setting device changes the physical parameter of spring compression to adjust the counterforce. By compressing the spring to different degrees, the system provides different activation thresholds. This parameter-based adjustment is simpler than structural modifications and enables easy reconfiguration of the pump activation level.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a spring is used as force-generating means to provide counterforce, then the pressure surface requires higher liquid pressure to activate the switch, but the system becomes more complex

Engineering Contradiction:
Improvestability of switch activationVSAvoidcomplexity of force-generating mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring as a force-generating means is a self-regulating component that automatically provides the necessary counterforce based on its compression state. It requires no external power source, control system, or additional actuation mechanisms. The spring simply compresses and exerts force passively, reducing system complexity while ensuring reliable and stable switch activation at the desired pressure threshold.

Inventive Principle:
Principle #25Self-service

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

Enables easy adjustment of the liquid level at which the pump is activated, allowing for multiple selectable starting levels without replacing the sensor, improving operational flexibility and efficiency.

Implementation Method 1

The force-generating means can preferably be a spring, in particular a compression spring, which generates a force directly or indirectly on the pressure surface counter to the first actuation direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The liquid pressure of the liquid in the container acts on this pressure surface. When the liquid level in the container rises, the liquid pressure acting on the pressure surface increases. The pressure creates a force on the pressure surface which moves this pressure surface in the first direction of movement

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Data Source

PatentEP2584109B1Fill level sensor
Publication Date: 2016.02.17 GRUNDFOS HLDG
  • EP2584109B1 patent drawingFigure 1
  • EP2584109B1 patent drawingFigure 2A~2C
  • EP2584109B1 patent drawingFigure 3A~3C

AI summary

The level sensor has electrical switch (24) which is coupled to the pressure surface (20), such that switch is operable by movement of pressure surface in first direction of movement. A force generating unit (32) generates force to act in a portion of the movement of pressure surface in first movement direction of pressure surface. A selector (34) selects first state in which force generating unit generates less or no force acting on pressure surface, and second state in which the force generating unit generates force on pressure surface. An independent claim is included for wastewater pump system.