Sterile Filter Life Extension via Compressed Air Pressure Equalization

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Solution Overview

Problem

Constant-pressure beverage filling machines face challenges in maintaining aseptic conditions due to dirt and humidity in ambient air, which reduces the service life of sterile filters used for pressure equalization in the product tank.

Innovation Solution

The method involves providing compressed air through a line branch connected to both the environment and the product tank via sterile filters, ensuring that only compressed air, filtered to reduce dirt and humidity, flows into the tank, thereby extending the life of the filters and maintaining aseptic conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ambient air is used for pressure equalization through sterile filters, then pressure equalization is achieved, but the service life of sterile filters is significantly reduced due to high dirt load and humidity

Engineering Contradiction:
Improveservice life of sterile filtersVSAvoiddirt load and humidity in ambient air
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Compressed air is supplied in advance to the product tank through the sterile filter before ambient air can be drawn in. The compressed air supply is controlled to match the breathing requirements of the tank, ensuring that the filter is always supplied with clean compressed air rather than contaminated ambient air, thereby extending its service life

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Compressed air acts as an intermediary substance to replace ambient air for pressure equalization purposes. Instead of allowing ambient air to pass through the sterile filter, compressed air is introduced as a cleaner alternative medium that achieves the same pressure equalization function without the harmful dirt and humidity components

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If compressed air is supplied to prevent ambient air intake, then filter service life is extended, but system complexity increases

Engineering Contradiction:
Improveservice life of sterile filtersVSAvoidcompressed air supply system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The compressed air supply system serves multiple functions: it provides pressure equalization for the product tank, prevents ambient air intake through the sterile filter, and can be integrated with existing factory air supply infrastructure. This multi-functionality justifies the added complexity by delivering multiple benefits from a single system addition

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

3Reliability

If sterile filters process ambient air continuously, then pressure equalization is maintained, but filtering efficiency decreases due to increased dirt load

Engineering Contradiction:
Improvepressure equalization reliabilityVSAvoidfiltering efficiency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Compressed air is prepared in advance through central treatment systems that remove particles, oil, and moisture before distribution. This pre-treated compressed air is then supplied to the product tank, ensuring that the sterile filter processes only clean air and maintains high filtering efficiency throughout its service life

Inventive Principle:
Principle #10Preliminary 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 approach effectively extends the service life of sterile filters by preventing ambient air from entering the tank, ensuring reliable pressure equalization without additional valves or ventilation lines, and maintaining aseptic conditions even during fluctuations in beverage fill levels.

Implementation Method 1

a line branch (5), which is connected via at least one sterile filter (6) to the product tank (3) and to the environment (7)

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

When there is a negative pressure in the product tank (3), a portion of the compressed air (8) supplied at the line branch (5), dependent on the negative pressure, flows through the sterile filter (6) into the product tank (3)

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 3

The beverage feed is then driven solely by hydrostatic pressure, depending on the level difference between the product tank's fill level and the product outlet of the filling valves

Methodology Applied
Scientific EffectHydrostatic pressure: Hydraulic Press

Data Source

PatentEP3659962A1Method for compensating pressure in a direct pressure filling machine and a direct pressure filling machine for drinks
Publication Date: 2020.06.03 KRONES AG
  • EP3659962A1 patent drawingFigure 1~2
  • EP3659962A1 patent drawingFigure 3
  • EP3659962A1 patent drawing

AI summary

A method for pressure equalization in a constant-pressure filling machine (1) for beverages (2) and a corresponding constant-pressure filling machine (1) are described. Accordingly, compressed air (8) is supplied at a branch line (5) which is connected on one side to the environment (7) and on the other side, via at least one sterile filter (6), to a product vessel (3) of the constant-pressure filling machine. When there is a negative pressure in the product vessel, a proportion (8a) of the supplied compressed air (8), dependent on the negative pressure, flows through the sterile filter (6) into the product vessel (3), and the remaining compressed air (8b) flows from the branch line into the environment.