Mixed-Geometry Coffee Roasting Drum with Inclined Axis
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Solution Overview
Problem
Conventional coffee roasting machines with rotating cylindrical drums are difficult to operate and produce coffee with high acrylamide content, which is suspected to be carcinogenic.
Innovation Solution
A coffee roasting machine with a mixed-geometry drum that incorporates circular-orbit stirring paddles and uses hot air with ambient temperature compressed air for roasting, reducing acrylamide content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a rotating cylindrical drum is used for coffee roasting, then the coffee can be roasted with hot air, but the operation becomes difficult and the coffee develops high acrylamide content
Solution Approach 1:
The patent applies asymmetry by replacing the conventional symmetric rotating cylindrical drum with an asymmetric mixed-geometry drum that has a cylindrical portion and a conical portion. This asymmetric geometry creates varied coffee bed depths and airflow patterns during rotation, which improves operational ease and reduces acrylamide formation by preventing stagnant zones where harmful compounds can accumulate.
Solution Approach 2:
The patent implements dynamics by using a drum that rotates on an inclined axis rather than a horizontal axis. This dynamic configuration causes the coffee to move through different zones (cylindrical and conical) during rotation, creating continuous motion patterns that enhance heat and mass transfer while reducing acrylamide formation and improving operational characteristics.
2Productivity
If a rotating cylindrical drum is used for coffee roasting, then the coffee can be processed, but the cycle becomes a tough test for the user
Solution Approach 1:
The asymmetric mixed-geometry drum design with cylindrical and conical portions creates natural coffee flow patterns during rotation that improve roasting efficiency. The varying drum geometry ensures continuous coffee movement and exposure to hot air, enhancing productivity while simplifying operation through automatic flow control.
Solution Approach 2:
The inclined axis rotation creates dynamic coffee movement through different drum zones, optimizing heat transfer and roasting uniformity. This dynamic configuration improves roasting efficiency and productivity while reducing operational complexity through self-regulating flow patterns.
3Object-affected harmful factors
If conventional roasting method with hot air only is used, then the process is simple, but the coffee has high acrylamide content
Solution Approach 1:
The asymmetric mixed-geometry drum design reduces acrylamide content through improved airflow distribution and coffee movement patterns. The cylindrical and conical portions work together to create optimal roasting conditions that lower harmful compound formation without requiring complex additional equipment.
Solution Approach 2:
The dynamic inclined axis rotation creates varying coffee bed depths and airflow patterns that naturally reduce acrylamide formation. This dynamic approach achieves lower harmful compounds through mechanical motion optimization rather than adding complex control systems or equipment.
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 machine facilitates easier operation and produces coffee with lower acrylamide levels, resulting in a more beneficial and efficient roasting process.
Implementation Method 1
hot air which is produced either by a gas burner or by electric resistances... hot air enters, and a large exhaust pipe on the top and at the back of its mixed geometry
Implementation Method 2
hot air which is produced either by a gas burner or by electric resistances
Implementation Method 3
at the back and bottom of the drum there are two pipes, which, when the coffee roasting process is complete, blow a quantity of ambient temperature compressed air into the drum
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This invention is a machine (Fig, 1), which processes raw (green) coffee with the use of hot air which is produced either by a gas burner or by electric resistances. This invention consists of the raw coffee receiving silo (Fig. 2), the roasting drum (Fig. 3), the roasting chamber, the shell collector at the back of it and the threshing floor, where the coffee cools after roasting, in its front part. The coffee roasting drum has a mixed geometry. In the lower part of the drum and, in particular, in its cylindrical part, there are small holes (Fig. 3, A). Inside it, the drum has circular-orbit stirring paddles. At the back and bottom of the drum there are two pipes, which, when the coffee roasting process is complete, blow a quantity of ambient temperature compressed air into the drum. Finally, at the top and at the back of the mixed-geometry drum there is a pipe for exhausting the hot air, together with the smoke from the roasting and the shells and the leftovers from the coffee processing.