Dual Volute Tongue Centrifugal Fan for Bidirectional Airflow

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Solution Overview

Problem

Existing centrifugal fans with a volute tongue design cannot effectively cut air flow when the impeller rotates in the reverse direction, leading to a significant decrease in air volume discharged, which affects the drying efficiency in dryers.

Innovation Solution

A centrifugal fan design featuring a housing with stacked and offset first and second volute tongues, along with a double-layer or single-layer impeller, where the first volute tongue guides air when the impeller rotates forward and the second volute tongue guides air when it rotates reverse, ensuring consistent air discharge in both directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single volute tongue is used in the centrifugal fan, then the structure is simple and cost-effective, but the air volume discharged sharply decreases when the impeller rotates in the reverse direction

Engineering Contradiction:

Improvevolute tongue structureVSAvoidair volume discharged

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The volute tongue is segmented into multiple independent volute tongues (first volute tongue and second volute tongue) arranged at different positions around the impeller. Each volute tongue is positioned to effectively cut air flow in a specific rotation direction, allowing the fan to maintain high air volume discharge in both forward and reverse rotation directions without significantly increasing overall structural complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The multiple volute tongues are asymmetrically arranged around the impeller at different angular positions. This asymmetric arrangement ensures that at least one volute tongue is always optimally positioned to cut air flow effectively regardless of the impeller's rotation direction, resolving the contradiction between structural simplicity and maintained productivity in bidirectional operation

Inventive Principle:

Principle #4Asymmetry

2Ease of operation

If the impeller rotates in the reverse direction (opposite to design direction), then the drying cylinder can prevent clothing entanglement, but the volute tongue cannot cut the air flow effectively, resulting in decreased air volume discharged

Engineering Contradiction:

Improvedrying process effectivenessVSAvoidair volume discharged

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The centrifugal fan is designed with multiple volute tongues that provide universal functionality for both forward and reverse rotation directions of the impeller. This multi-functional design ensures that the fan can effectively discharge air volume in both rotation directions, supporting the drying cylinder's bidirectional operation to prevent clothing entanglement while maintaining drying efficiency

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The arrangement of multiple volute tongues creates a dynamic system where the effective volute tongue changes depending on the impeller's rotation direction. As the impeller rotates in different directions, different volute tongues become optimally positioned to cut air flow, ensuring continuous effective air discharge regardless of rotation direction and maintaining ease of operation for the drying process

Inventive Principle:

Principle #15Dynamics

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 design ensures a sufficient air volume is maintained when the impeller rotates in either direction, enhancing the drying effect by preventing a sharp decrease in air discharge, thus improving the performance of dryers.

Implementation Method 1

Based on the principle of converting kinetic energy into potential energy, a centrifugal fan uses a high-speed rotating impeller to accelerate gas

Methodology Applied

Scientific EffectKinetic energy conversion:

Implementation Method 2

the volute tongue can cut an air flow driven by the impeller so that the air flow is discharged from the air outlet

Methodology Applied

Scientific EffectFlow cutting and guidance:

Implementation Method 3

then decelerate it, and change a flow direction thereof, thus converting kinetic energy into potential energy

Methodology Applied

Scientific EffectKinetic to potential energy conversion:

Data Source

PatentUS11808280B2Centrifugal fan and clothing dryer

Publication Date: 2023.11.07 QINGDAO HAIER DRUM WASHING MACHINE CO LTD

AI summary

A centrifugal fan and a clothing dryer. The centrifugal fan includes a housing as well as an impeller and a worm tongue disposed in the housing. The housing has an air inlet and an air outlet. The volute tongue includes a first volute tongue and a second volute tongue that are stacked and staggered. The first volute tongue cuts the air blown from the impeller and guide the air to the air outlet when the impeller rotates forward. The second volute tongue cuts the air blown from the impeller and guide the air to the air outlet when the impeller rotates backward. When the impeller rotates, the first volute tongue or the second volute tongue can cut the air blown from the impeller and guide the air to the air outlet, so that the centrifugal fan can blow out air when the impeller rotates forward and backward.