Eccentric Screw Pump Spray Device for Blob-Free Dosing
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Solution Overview
Problem
Existing spray devices face challenges in achieving precise volumetric dosing and variable spray patterns, particularly with viscous fluids, due to reliance on the Venturi effect which can lead to inaccuracies and blob formation on substrates.
Innovation Solution
A spray device equipped with an eccentric screw pump for volumetric dosing, featuring a spray head with a gas cap and turbulence element, allowing independent regulation of fluid and gas flow, and optional heating/cooling for viscosity adjustment, along with interchangeable components for adaptable spray patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a Venturi nozzle is used for spraying, then fluid can be sprayed using gas flow, but precise volumetric dosing cannot be achieved and blob formation occurs on substrates
Solution Approach 1:
The device separates the dosing function from the spraying function. The dosing pump independently meters the fluid volume before it enters the spray head, while the Venturi nozzle handles only the gas flow and atomization. This segmentation allows precise volumetric control without the interference of gas flow variations that cause blobbing in conventional integrated systems.
Solution Approach 2:
The metering pump acts as an intermediary between the fluid supply and the spray head. It precisely controls the fluid delivery volume independent of the gas flow, serving as a mediator that decouples the dosing accuracy from the spraying process and prevents direct coupling between gas pressure variations and fluid dosing.
2Reliability
If the Venturi effect is used for spraying, then spraying can be achieved with gas flow, but inaccuracies occur due to thermal expansion and viscosity changes
Solution Approach 1:
The metering pump is designed to compensate for parameter changes in the fluid, including temperature-induced thermal expansion and viscosity variations. By adjusting the pump's metering parameters based on fluid conditions, the system maintains reliable and accurate spraying performance across different fluid properties and environmental conditions.
Solution Approach 2:
The system dynamically adapts to changing fluid properties through the metering pump's ability to adjust its delivery parameters in real-time. This dynamic adjustment capability allows the system to maintain spray accuracy even when fluid viscosity or temperature changes, making the system both reliable and adaptable.
3Ease of manufacture
If a fixed spray head design is used, then manufacturing is simplified, but variable spray patterns cannot be achieved
Solution Approach 1:
The spray head incorporates interchangeable components, particularly the gas cap and vortex element, that can be swapped to change spray patterns. This dynamic reconfiguration capability allows a single base spray head design to produce multiple spray patterns, maintaining ease of manufacture while providing versatility.
Solution Approach 2:
The spray head is segmented into interchangeable modules (gas cap, vortex element, nozzle body). This segmentation allows different combinations of components to create various spray patterns while keeping the manufacturing of each individual module simple and standardized.
4Productivity
If rapid start and stop of spraying is required, then productivity increases, but blob formation and dosing inaccuracies occur
Solution Approach 1:
The metering pump is designed to rapidly respond to start/stop commands and can pre-position the fluid delivery. This preliminary action capability allows the pump to quickly adjust from zero to full delivery or vice versa without the lag that causes blobbing, enabling rapid productivity cycles while maintaining dosing precision.
Solution Approach 2:
The independent metering pump replaces the traditional mechanical coupling between gas flow and fluid delivery. This substitution allows electronic or programmatic control of the pump's metering rate, enabling rapid start/stop responses with precise dosing control that isn't limited by gas flow dynamics.
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, blob-free spraying of various fluid viscosities with adjustable spray patterns, preventing inaccuracies due to thermal expansion and allowing for ramp-like start and end of the spraying process.
Implementation Method 1
a metering unit, which is an eccentric screw pump, for volumetric metering of the fluid
Implementation Method 2
The metering device is, in particular, a first metering device of the spraying device. The spraying device can comprise several, for example, two, metering devices.
Implementation Method 3
The spray head includes a vortex element for swirling the gas, the vortex element being made of a porous plastic, ceramic, or metal material.
Implementation Method 4
The vortex element is made of a porous plastic, ceramic, or metal material.
Implementation Method 5
optional heating/cooling for viscosity adjustment
Implementation Method 6
A heating and/or cooling device can be provided for heating or cooling the fluid in order to change its viscosity.
Implementation Method 7
The supplied fluid is entrained and sprayed by a gas, such as air, flowing through the Venturi nozzle.
Data Source
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AI summary
A spraying device (1) for spraying a fluid with a metering device (2), in particular an eccentric screw pump, for volumetric metering of the fluid and a spraying device (34) which is configured to spray the fluid metered by the metering device (2) with the aid of a gas.