Centrifugal Apparatus Rotational Direction Detection via Frequency Data

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Solution Overview

Problem

Existing methods for determining the correct rotational direction of centrifugal apparatuses are often manual, require additional instrumentation, and are unreliable, especially when power estimates are used, as forward and reverse rotational speeds can have the same shaft power requirement, making it difficult to distinguish the correct direction.

Innovation Solution

A method that involves rotating the centrifugal apparatus in both forward and reverse directions, acquiring frequency data, and comparing it within specific frequency ranges to determine the correct rotational direction, utilizing modern frequency converters to estimate induction motor load conditions without additional instrumentation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If visual inspection is used to determine rotational direction, then the method is simple to implement, but it requires additional personnel and cannot be automated

Engineering Contradiction:

Improveautomation of rotational direction detectionVSAvoidcomplexity of detection system

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The centrifugal apparatus performs self-diagnosis by using its own operational parameters (power consumption, flow rate, pressure) to automatically determine rotational direction, eliminating the need for external inspection personnel or complex additional instrumentation

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces manual visual inspection with automated sensor-based measurement systems that detect rotational direction through electrical and fluid dynamic parameters, substituting mechanical/human inspection with electronic detection

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Extent of automation

If flow rate or pressure measurements are used to determine rotational direction, then automated detection is achieved, but additional instrumentation must be installed in the pump system

Engineering Contradiction:

Improveautomated rotational direction detectionVSAvoidadditional instrumentation required

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The patent utilizes existing multi-functional parameters (power consumption and flow rate/pressure measurements) that serve both operational monitoring and rotational direction detection purposes, eliminating the need for dedicated additional instrumentation

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own operational parameters for self-diagnosis of rotational direction, avoiding the need for external specialized measurement devices

Inventive Principle:

Principle #25Self-service

3Extent of automation

If power estimates from frequency converter are used to determine rotational direction, then automated detection is possible, but it is unreliable because forward and reverse rotational speeds have the same shaft power requirement

Engineering Contradiction:

Improveautomated rotational direction detectionVSAvoidreliability of rotational direction detection

Core Design Contradiction:

Extent of automationVSReliability

Solution Approach 1:

The patent exploits the asymmetric relationship between rotational direction and fluid dynamic parameters (flow rate and pressure), where the magnitude and/or phase of these parameters differ between forward and reverse rotation, providing reliable directional discrimination

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The system changes from using power consumption alone (which is symmetric for forward/reverse rotation) to using flow rate and/or pressure parameters (which are asymmetric), thereby achieving reliable rotational direction detection

Inventive Principle:

Principle #35Parameter changes

4Device complexity

If visual inspection is used to determine rotational direction, then no additional instrumentation is needed, but the centrifugal apparatus must be in a position accessible for inspection

Engineering Contradiction:

Improvesimplicity of detection systemVSAvoidease of rotational direction detection

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The patent replaces visual inspection requiring physical access with remote sensor-based detection using electrical and fluid dynamic parameters, allowing rotational direction determination regardless of apparatus positioning

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9715478B2Method for detecting the correct rotational direction of a centrifugal apparatus, and a centrifugal apparatus assembly

Publication Date: 2017.07.25 ABB (SCHWEIZ) AG

AI summary

A method is provided for detecting the correct rotational direction of a centrifugal apparatus. The method includes rotating the centrifugal apparatus in a first direction, acquiring first frequency data relating to the step of rotating the centrifugal apparatus in the first direction, rotating the centrifugal apparatus in a second direction, which is opposite to the first direction, and acquiring second frequency data relating to the step of rotating the centrifugal apparatus in the second direction. The method also includes detecting the correct rotational direction of the centrifugal apparatus based on comparing the first frequency data with the second frequency data, the comparison being carried out with respect to at least one significant frequency range. In each of the at least one significant frequency range, a smaller magnitude is interpreted as an indication of the correct rotational direction.