Pellet Grill Burn Pot Geometry for High Heat and Low Ash

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Solution Overview

Problem

Conventional pellet grills face challenges in achieving high cooking temperatures and effectively managing ash and grease within the cooking chamber, leading to inefficiencies and potential contamination.

Innovation Solution

The design incorporates a burn pot with an inwardly-tapered sidewall to centralize heat and restrict ash escape, a fuel grate with openings to direct ash downward, and a grease deflection bar assembly to manage grease, along with a control system for detecting and managing auger jams, flame outs, and fuel levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional burn pots with vertical or outwardly-tapered sidewalls are used, then ash can escape upwardly into the cooking chamber, but heat distribution is less efficient and cooking temperatures are lower

Engineering Contradiction:
Improvecooking temperatureVSAvoidash contamination
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The burn pot sidewall is inverted from the conventional vertical or outwardly-tapered design to an inwardly-tapered design. This inversion causes ash to be directed downward and outward toward the exhaust opening rather than upward into the cooking chamber, while simultaneously concentrating heat in the center for more efficient cooking at higher temperatures.

Inventive Principle:
Principle #13The other way round (Inversion)

2Object-affected harmful factors

If no grease management system is implemented, then the structure remains simple, but grease accumulates and causes contamination and safety issues

Engineering Contradiction:
Improvegrease contaminationVSAvoidstructure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The grease management system extracts grease from the cooking chamber environment by providing dedicated grease channels and grease cups that collect and remove grease before it can accumulate and cause contamination or safety hazards. This separates the grease management function from the cooking space.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Grease deflection bars serve as intermediary elements that intercept grease flow from the cooking grate and redirect it into grease channels. These deflection bars act as mediators between the cooking surface and the grease collection system, preventing direct grease accumulation in the cooking chamber.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If manual ash removal is required, then the device complexity is low, but operational efficiency decreases and user burden increases

Engineering Contradiction:
Improveoperational efficiencyVSAvoidash management system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The ash management system is designed to be self-service through the inwardly-tapered burn pot sidewall that passively directs ash downward and outward toward the exhaust opening using gravity and combustion airflow patterns. This eliminates the need for active mechanical removal mechanisms while maintaining low ash contamination in the cooking chamber.

Inventive Principle:
Principle #25Self-service

4Temperature

If heat is not centralized, then heat distribution is more uniform across the burn surface, but cooking temperatures cannot reach higher levels

Engineering Contradiction:
Improvecooking temperatureVSAvoidheat distribution pattern
Core Design Contradiction:
TemperatureVSShape

Solution Approach 1:

The inwardly-tapered burn pot sidewall creates local quality differentiation by concentrating heat in the central region where cooking occurs, while allowing ash to be directed outward at the periphery. This spatial differentiation of heat concentration and ash ejection paths enables both high cooking temperatures and effective ash management.

Inventive Principle:
Principle #3Local quality

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 enables higher cooking temperatures, reduces ash and grease contamination, and enhances operational efficiency through improved heat management and automated detection protocols.

Implementation Method 1

Combustion and/or burning of the pellet fuel within the burn pot produces, generates, and/or outputs heat

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

a fuel grate with openings to direct ash downward

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 3

A motor-driven fan is typically implemented to assist with combusting the pellet fuel, and/or to assist with distributing and/or circulating heat (e.g., as may be produced by the combusted pellet fuel) throughout the cooking chamber

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Data Source

PatentEP3883439B1Pellet grills
Publication Date: 2024.06.12 WEBER-STEPHEN PRODUCTS
  • EP3883439B1 patent drawingFigure 1
  • EP3883439B1 patent drawingFigure 2
  • EP3883439B1 patent drawingFigure 3

AI summary

Pellet grills and associated methods of operation are disclosed. An example pellet grill includes a burn pot configured to combust pellet fuel received within the burn pot. The pellet grill further includes an auger configured to deliver the pellet fuel to the burn pot. The pellet grill further includes an auger motor operatively coupled to the auger. The pellet grill further includes one or more processors configured to determine whether a shutdown sequence of the pellet grill has been initiated. The one or more processors are further configured, in response to determining that the shutdown sequence has been initiated, to command the auger motor to reverse a direction of rotation of the auger. The reversal is to cause pellet fuel which the auger has not yet delivered to the burn pot to be purged in a direction away from the burn pot.