Powder Conveying Valve Control for Independent Flow and Dose

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Solution Overview

Problem

Existing powder conveying devices for coating systems cannot independently adjust the flow velocity of powder flowing through the powder line or the powder cloud generated by the applicator without affecting the amount of powder conveyed, leading to imprecise control over the spread of the powder cloud and inability to separately adjust flow rate and amount.

Innovation Solution

A powder conveying device with a working container that can be pressurized, featuring a powder outlet valve controlled by a pulse-coded signal to adjust the amount of powder conveyed, and an inlet for transport air introduced through an annular gap to minimize turbulence and wear, allowing independent adjustment of flow velocity and powder amount.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If trigger air is fed into the supply hose to adjust powder flow rate, then the powder flow rate can be controlled, but the powder quantity and flow rate cannot be adjusted independently

Engineering Contradiction:
Improvepowder flow rateVSAvoidindependent adjustment capability
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

The system is divided into two independent control paths: one for powder quantity control via the powder outlet valve, and another for flow rate control via the transport air inlet. This segmentation allows independent adjustment of powder quantity and flow rate without mutual interference, resolving the contradiction between flow rate control and independent adjustment capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Transport air is introduced as an intermediary substance through the annular gap to control powder flow rate independently. The transport air acts as a mediator that influences powder movement without directly controlling powder quantity, enabling separate adjustment of flow rate and quantity parameters.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If compressed air pressure in the powder reservoir is increased to increase powder quantity, then more powder can be conveyed, but the powder flow rate also increases uncontrollably

Engineering Contradiction:
Improvepowder quantityVSAvoidpowder flow rate
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The control system is segmented into independent components: the powder outlet valve controls powder quantity by regulating the opening duration, while the transport air inlet separately controls flow rate by adjusting air pressure. This allows powder quantity to be increased without uncontrollably increasing flow rate, as each parameter has its own control mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The powder outlet valve operates periodically, opening for controlled time intervals to deliver precise powder quantities. This periodic action decouples quantity control from continuous flow rate, allowing quantity adjustment without proportional flow rate increase.

Inventive Principle:
Principle #19Periodic action

3Ease of operation

If trigger air pressure is increased to clear the supply hose during cleaning, then cleaning effectiveness improves, but the maximum pressure is limited by reservoir pressure

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidtrigger air pressure limit
Core Design Contradiction:
Ease of operationVSStress or pressure

Solution Approach 1:

The system introduces a separate air supply dimension for cleaning operations, independent of the reservoir pressure system. The transport air inlet can be supplied from an external compressed air source, allowing cleaning pressure to exceed reservoir pressure without being constrained by it, thereby improving cleaning effectiveness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If conventional powder line design is used, then powder can be conveyed, but turbulence and wear on the powder line occur

Engineering Contradiction:
Improvepowder conveyanceVSAvoidturbulence and wear
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The annular gap inlet is designed with specific local geometric properties that optimize air flow characteristics. The环形 structure and positioning create a localized flow pattern that reduces turbulence at the inlet point, preventing downstream wear while maintaining effective powder conveyance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The periodic opening and closing of the powder outlet valve creates pulsed powder flow that, when combined with continuous transport air, reduces turbulence compared to continuous high-velocity flow. This periodic action allows effective conveyance with reduced harmful effects on the powder line.

Inventive Principle:
Principle #19Periodic action

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

Enables precise control over the flow velocity and amount of powder conveyed, optimizing the spread of the powder cloud and improving the quality of powder application by reducing turbulence and wear on the powder line.

Implementation Method 1

a working container (1) which is designed and operable to be pressurized

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

by supplying transport air (TL) into the powder line (40)

Methodology Applied
Scientific EffectFluidization: Fluidisation

Implementation Method 3

the inlet for transport air (TL) is designed as an annular gap (94)

Methodology Applied
Scientific EffectTurbulence reduction: Turbulence

Data Source

PatentEP3238832B2Powder conveying device for conveying coating powder to a powder applicator, powder coating installation and method for operating the powder conveying device
Publication Date: 2024.02.14 WAGNER INT
  • EP3238832B2 patent drawingFigure 1
  • EP3238832B2 patent drawingFigure 2~3c
  • EP3238832B2 patent drawingFigure 4

AI summary

The powder conveying device according to the invention for conveying coating powder to a powder applicator comprises a working container (1) which is designed and can be operated in such a way that it can be pressurized. The working container (1) also includes a powder inlet (50) and a powder outlet (51.1), the powder outlet (51.1) being connected to a powder outlet valve (13). In addition, a powder line (40) is provided, which is connected to the powder outlet valve (13) on the inlet side and which has an inlet (17) for transport air (TL) on the inlet side. The powder line (40) can be connected to a powder applicator (4; 5) on the outlet side. In addition, a controller (80) is provided which is designed and can be operated in such a way that it controls the powder quantity (Q) to be conveyed by repeatedly opening and closing the powder outlet valve (13).