Capacitive Sensor for Screw Conveyor Moisture Monitoring

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Screw conveyors used in sulfur palletization plants face frequent shutdowns due to moisture accumulation, leading to costly manual cleanings and unnecessary production stoppages, as existing methods lack an effective online monitoring mechanism to detect dielectric properties of conveyed materials.

Innovation Solution

Integration of a capacitive sensor within the screw conveyor system, comprising a parallel plate capacitor with conductive plates, to measure dielectric properties of the conveyed material by applying voltages and measuring currents, allowing for real-time characterization of moisture content and composition, thereby identifying the need for cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If monthly manual cleaning is performed to remove moisture accumulation, then the screw conveyor is maintained operational, but unnecessary shutdowns occur and production time is lost

Engineering Contradiction:

Improveconveyor operational statusVSAvoidproduction shutdown time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The capacitive sensor performs preliminary detection of moisture accumulation by measuring dielectric properties of the conveyed material in real-time. This early detection allows operators to schedule cleaning only when actually needed, preventing unnecessary shutdowns while maintaining conveyor reliability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sensor provides continuous feedback on the dielectric properties of the material, which correlates with moisture content. This feedback loop enables data-driven decision-making for cleaning schedules, optimizing the balance between maintaining operational reliability and minimizing production time loss

Inventive Principle:

Principle #23Feedback

2Reliability

If frequent manual cleaning is scheduled to prevent moisture accumulation, then conveyor reliability is maintained, but cleaning costs and operational disruptions increase

Engineering Contradiction:

Improveconveyor operational statusVSAvoidproduction output

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The capacitive sensor enables the system to monitor its own operational condition (moisture accumulation) automatically. This self-monitoring capability eliminates the need for conservative frequent cleaning schedules, allowing production to continue at full capacity until actual cleaning is required

Inventive Principle:

Principle #25Self-service

3Device complexity

If no online monitoring is implemented, then device complexity is low, but conveyor trips occur frequently causing shutdowns

Engineering Contradiction:

Improvemonitoring system complexityVSAvoidconveyor operational status

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces complex mechanical monitoring systems with an electrical field-based capacitive sensor. This substitution measures dielectric properties through electrical fields without mechanical contact, achieving reliable moisture detection with minimal added complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sensor detects changes in dielectric properties of the conveyed material, which change with moisture content. By monitoring this physical parameter, the system achieves reliable conveyor operation monitoring with a simple, elegant measurement approach

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

The capacitive sensor enables in-situ monitoring of dielectric properties, reducing unnecessary shutdowns and manual cleanings by providing timely cleaning notifications, thus minimizing operational disruptions and costs.

Implementation Method 1

The capacitive sensor includes a first conductive plate and a second conductive plate spaced apart from one another to allow the conveyed material to travel between the first and second conductive plates

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

online permittivity-based sensors for integration into screw conveyors for detecting dielectric properties of a material being conveyed therethrough

Methodology Applied

Scientific EffectDielectric Permittivity: Dielectric Permittivity

Data Source

PatentUS20220340368A1Relative-permittivity-based online monitoring system for screw conveyors

Publication Date: 2022.10.27 SAUDI ARABIAN OIL CO

AI summary

A screw conveyor system includes a conveyor body defining a conveyor cavity. The conveyor body includes an inlet for a conveyed material and an outlet. A screw blade is rotatably connected to the conveyor body via a shaft. The screw blade extends within the conveyor cavity between the inlet and the outlet. A hanger bearing support extends from an interior surface of the conveyor body into the conveyor cavity and a hanger bearing is attached to the hanger bearing support with the hanger bearing contacting the shaft to support the screw blade. A sensor support structure is connected to the hanger bearing support and the conveyor body. A capacitive sensor is attached to the sensor support structure and includes a first conductive plate and a second conductive plate spaced apart from one another to allow the conveyed material to travel between the first and second conductive plates.