Draft Inducer Blower With Adjustable Dilution Air Intake

Solution Overview

Problem

Existing draft inducer blowers for gas-fueled heater systems face inefficiencies due to over- or under-drawing of exhaust gases, leading to imbalanced air-fuel mixtures and reduced performance across varying vent lengths and appliance types, especially when using single-speed motors.

Innovation Solution

A draft inducer blower assembly with a dilution air intake passage configurable between low and high flow settings, allowing adjustable intake of dilution air to match vent lengths and appliance requirements, coupled with a single-speed motor operation, using a valve or movable parts to optimize the ratio of dilution air to exhaust gases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-speed blower is used, then the device complexity is reduced, but the system efficiency deteriorates when vent length does not match the fixed blower speed

Engineering Contradiction:

Improveblower speed control complexityVSAvoidsystem efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The dilution air intake passage is made adjustable between low flow and high flow configurations, allowing the system to dynamically adapt the dilution air intake rate to match different vent lengths and appliance requirements, thereby maintaining optimal system efficiency without requiring multiple blower speeds

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the flow parameter of the dilution air intake passage to optimize performance. By adjusting the passage configuration between low and high flow settings, the system can match different exhaust gas draw rates required by various appliances and vent lengths while using a single-speed motor

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If a two-speed blower is used, then the adaptability to different vent lengths is improved, but the device complexity increases due to additional sensors and control components

Engineering Contradiction:

Improvevent length adaptabilityVSAvoidcontrol system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the speed control complexity from the blower system and relocates the adjustment mechanism to the dilution air intake passage. This allows the system to achieve adaptability to different vent lengths through passage configuration rather than through complex speed control electronics and sensors

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The dilution air intake passage acts as an intermediary mechanism that provides the adaptability function. Instead of directly controlling blower speed to match vent lengths, the system uses the adjustable passage to modulate dilution air intake, thereby achieving the same adaptive effect with simpler control

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If a two-speed blower is used, then the efficiency for different appliances is improved, but the device complexity increases due to multiple operating modes

Engineering Contradiction:

Improveappliance efficiencyVSAvoidoperating mode complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The dilution air intake passage is made adjustable between low flow and high flow configurations, allowing the system to dynamically adapt the dilution air intake rate to match different vent lengths and appliance requirements, thereby maintaining optimal system efficiency without requiring multiple blower speeds

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the flow parameter of the dilution air intake passage to optimize performance. By adjusting the passage configuration between low and high flow settings, the system can match different exhaust gas draw rates required by various appliances and vent lengths while using a single-speed motor

Inventive Principle:

Principle #35Parameter changes

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 configuration ensures efficient operation across different vent lengths and appliance types, preventing over- or under-drawing of exhaust gases, maintaining optimal burner performance and efficiency without the need for additional sensors or multiple speed settings.

Implementation Method 1

The blower is configured to draw dilution air into the blower, mix the dilution air with the exhaust gases, and facilitate flow of the mixed air and exhaust gases through the vent

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 2

The dilution air intake passage is more restrictive of intake of dilution air in the low flow configuration than in the high flow configuration

Methodology Applied

Scientific EffectFlow restriction:

Data Source

PatentUS11603851B2Draft inducer blower

Publication Date: 2023.03.14 REGAL BELOIT AMERICA INC

AI summary

A draft inducer blower assembly includes a blower having a fan, a dilution air intake passage, an exhaust gas intake passage, and a discharge passage. The blower is configured to operatively connect to a heater system in a manner to facilitate flow of combustion air into a combustion chamber and to draw dilution air into the blower and to mix the dilution air with the exhaust gases and to facilitate flow of the mixed air and exhaust gases through the vent. The dilution air intake passage is positionable in at least a low flow configuration and a high flow configuration. The dilution air intake passage is more restrictive of intake of dilution air in the low flow configuration than in the high flow configuration.