Fan Inlet Ring Channel for Condensate-Resistant Flow Measurement

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Solution Overview

Problem

Existing fan volume flow measurement devices are prone to contamination and condensate, leading to inaccurate control and poor tracking of characteristics, especially with forward-curved fans, which are noisy, and backward curved fans, which are susceptible to blockages in pressure difference measurements.

Innovation Solution

A device with a closed ring channel having multiple openings in the outer wall and a measuring opening positioned above the equator, combined with a reference tube and thermal pressure difference sensor, prevents condensate from blocking the measurement, allowing for accurate volume flow determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pressure difference measurements are carried out using hose rings with openings, then volume flow can be determined, but the measurements become susceptible to contamination and condensate blockages

Engineering Contradiction:
Improvevolume flow measurement accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The measuring opening is extracted from the problematic area where condensate accumulates (bottom of ring channel) and positioned in a clean area (above equator) where condensate cannot block it, while still allowing pressure difference measurement to determine volume flow

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Multiple openings in the ring channel act as intermediaries that allow condensate to drain away from the measurement path, while the positioned measuring opening provides the necessary pressure difference measurement without being blocked by condensate

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If forward-curved fans are used to achieve certain delivery rates, then volume flow requirements can be met, but noise levels become very high

Engineering Contradiction:
Improvedelivery rateVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The device provides accurate feedback on actual volume flow delivered by the fan, enabling control systems to optimize fan operation for quietest performance at each delivery rate, and to detect deviations from expected characteristics that may indicate problems requiring attention

Inventive Principle:
Principle #23Feedback

3Ease of operation

If measuring openings are positioned in conventional locations, then pressure difference measurement is simple, but condensate blocks the openings and prevents proper measurement

Engineering Contradiction:
Improvemeasurement simplicityVSAvoidvolume flow measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The measuring opening is positioned asymmetrically above the equator of the ring channel, away from the symmetric condensate accumulation zone at the bottom, creating a design where the measurement function is separated from the condensate trap function

Inventive Principle:
Principle #4Asymmetry

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 solution provides precise and reliable volume flow measurement, enabling effective control of fan speed and operation, reducing noise and energy consumption while maintaining accurate tracking of fan characteristics.

Implementation Method 1

a pressure difference sensor for connection to the measurement port and the reference tube

Methodology Applied
Scientific EffectPressure difference measurement: Pressure Gradient

Implementation Method 2

the sensor is a thermal pressure difference sensor

Methodology Applied
Scientific EffectThermal effect: Thermocouple

Implementation Method 3

the measuring opening is advantageously positioned in such a way that it is arranged above the equator of the ring channel when the ring channel is installed as intended. In this way, when condensate forms inside the ring channel, the condensate can flow out of the openings located below

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2508811B1Device for calculating the volume flow transported by a ventilator
Publication Date: 2014.03.12 ZEHNDER GROUP INTERNATIONAL AG

AI summary

The invention relates to a device for determining the volume flow transported by a fan. In order to provide a generic device which is as accurate as possible, allows for simple evaluation and is also not susceptible to dirt and condensate, the invention proposes a device for determining the volume flow transported by a fan having ● a device to be arranged in the area of ​​an inlet nozzle of the fan closed ring channel with a large number of openings in the outer wall and at least one measuring opening, ● a reference tube for positioning in an ambient atmosphere and ● a pressure difference sensor for connection to the measuring opening and the reference tube.