RF Drying of Cigar Rods for Uniform Moisture

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Solution Overview

Problem

Current cigar manufacturing processes are slow, labor-intensive, and result in inhomogeneous moisture content, leading to inefficient production and quality issues due to the use of infrared and microwave radiation, which causes uneven drying and damage to cigars.

Innovation Solution

Drying cigars in a continuous layer using radio frequency (RF) radiation, which applies heat uniformly and adjusts power based on moisture levels, ensuring consistent moisture reduction and reducing processing time and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If infrared radiation is used to dry cigar rods, then the surface of the cigar rods is heated and dried, but the centre of the cigar rod dries more slowly causing uneven drying and potential damage to the outer wrap

Engineering Contradiction:
Improvesurface temperature of cigar rodVSAvoidmoisture uniformity of cigar rod
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent changes the electromagnetic radiation parameter from infrared to radio frequency, which fundamentally alters the heating mechanism. RF radiation penetrates deeper into the cigar rod and generates heat throughout the entire volume uniformly, rather than heating only the surface. This parameter change resolves the contradiction by achieving both effective surface drying and uniform internal moisture distribution.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If microwave radiation is used to dry cigar rods, then drying speed is increased, but interference patterns create hot and cold spots causing uneven drying

Engineering Contradiction:
Improvedrying speedVSAvoidmoisture uniformity of cigar rod
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the electromagnetic radiation frequency parameter from microwave to radio frequency. RF radiation at the frequencies used (typically 27.12 MHz or 6.78 MHz) does not create the interference patterns that microwaves do. This parameter change maintains high drying speed while achieving uniform moisture distribution throughout the cigar rod, eliminating hot and cold spots.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If cigars are dried in bundles of approximately 1800 rods, then processing capacity is maintained, but outer edge cigars over dry while centre cigars under dry

Engineering Contradiction:
Improveprocessing capacityVSAvoidmoisture consistency across bundle
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent segments the drying process from the traditional bundle method by drying cigars in a continuous single layer rather than in large bundles. This segmentation allows each cigar to be exposed uniformly to the RF radiation field, eliminating the moisture gradient problem where outer edge cigars over-dry and centre cigars under-dry. The continuous layer configuration maintains processing capacity while ensuring moisture consistency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical bundle-based drying system with an electromagnetic RF heating system. This substitution allows for uniform energy distribution throughout the continuous layer of cigars, eliminating the moisture unevenness caused by bundle configuration. The RF field penetrates and heats all cigars in the layer simultaneously and uniformly.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If standard conditioning room drying is used, then moisture equilibration is achieved, but the process is slow taking approximately six working days

Engineering Contradiction:
Improvemoisture equilibrationVSAvoiddrying time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent utilizes dielectric heating, a form of electromagnetic heating, to rapidly remove moisture from the cigar rods. The RF radiation causes water molecules to rotate and generate heat internally, accelerating the evaporation and removal of moisture. This phase transition approach reduces drying time from six working days to a fraction of that time while achieving the required moisture equilibration and firmness.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent replaces the passive thermal diffusion drying process in conditioning rooms with active RF electromagnetic heating. This substitution dramatically accelerates the moisture removal process by directly heating the water molecules within the tobacco material, reducing drying time from six days to minutes or hours while maintaining moisture control and product quality.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

RF drying significantly reduces processing time, improves moisture consistency, and enhances cigar firmness and smoking quality, while minimizing energy consumption and product rejection.

Implementation Method 1

applying a radio frequency, RF, radiation to the plurality of arranged cigar rods having a first moisture level to thereby heat the cigar rods

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 2

heat the cigar rods at a temperature within the range of 88° - 100°C (190° - 212° F) and reduce the first moisture level

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2524607B1Method and system for manufacturing tobacco articles
Publication Date: 2020.04.08 JT INTERNATIONAL SA
  • EP2524607B1 patent drawingFigure 1A~1B
  • EP2524607B1 patent drawingFigure 2~4

AI summary

A method of drying cigars during their manufacture comprises the steps of: providing a plurality of tobacco rods; arranging the plurality of tobacco rods in a continuous layer; and applying a radio frequency, RF, radiation to the plurality of arranged tobacco rods having a first moisture level to thereby heat the tobacco rods at a temperature within the range of 190° - 212° F and reduce the first moisture level.