Liquid Discharging Head Nozzle Segmentation for High-Viscosity Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid discharging apparatuses face challenges in efficiently discharging high-viscosity liquids due to increased frictional resistance between the nozzle inner wall and the liquid, leading to energy loss and difficulty in pressurizing the liquid, which affects the flow path resistance and discharge efficiency.
Innovation Solution
A liquid discharging head with a control section that includes a first nozzle portion, a second nozzle portion with a larger sectional area, a liquid chamber, and a pressure changing section driven by a control signal, where the liquid surface is drawn into the second nozzle portion and its shape is inverted to facilitate efficient discharge by minimizing frictional forces and optimizing flow velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the straight portion of the nozzle is lengthened to form a liquid film and reduce frictional resistance, then the discharge efficiency of high-viscosity liquid is improved, but the flow path resistance increases and it becomes difficult to pressurize the liquid inside the nozzle using little energy
Solution Approach 1:
The nozzle is divided into multiple sections with different diameters: a first nozzle portion with a smaller diameter that forms a liquid film to reduce friction, and a second nozzle portion with a larger diameter that reduces flow path resistance. This segmentation allows each portion to optimize for its specific function, resolving the contradiction between reducing friction and maintaining low flow resistance.
Solution Approach 2:
Different portions of the nozzle are given different local properties: the first nozzle portion has a smaller diameter to create the liquid film effect for high-viscosity liquids, while the second nozzle portion has a larger diameter to reduce overall flow resistance. This local differentiation allows the system to achieve both reduced friction and acceptable pressure requirements.
2Loss of energy
If the meniscus is greatly drawn in to form a liquid film inside the nozzle, then the energy loss at the boundary between the inner wall surface and the liquid is reduced, but the flow path resistance increases
Solution Approach 1:
The nozzle flow path is segmented into two distinct portions: the first portion where the meniscus is drawn in to form a liquid film that minimizes boundary energy loss, and the second portion with larger diameter that compensates for the increased flow path resistance by providing a more spacious flow channel.
Solution Approach 2:
The liquid film itself acts as an intermediary layer between the liquid and the nozzle wall, reducing direct contact and frictional energy loss. The second nozzle portion with larger diameter serves as an intermediary flow channel that balances the resistance introduced by the first portion.
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 solution enables stable and efficient discharge of high-viscosity liquids with reduced energy loss, allowing for the formation of small droplets and high-resolution images on recording media while maintaining productivity and reducing the size of the discharging apparatus.
Implementation Method 1
a pressure changing section which changes a pressure of the liquid inside the liquid chamber
Implementation Method 2
the frictional resistance between the inner wall surface of the nozzle and the liquid to be discharged increases in proportion to the viscosity
Data Source
AI summary
A liquid-discharging-head includes a nozzle having a first-nozzle-portion having a first-sectional-area and a second-nozzle-portion having a second-sectional-area larger than the first-sectional-area, a liquid chamber which communicates with the nozzle, and a piezoelectric-element which changes a pressure inside the liquid chamber, in which the piezoelectric-element is driven from the control section, and the liquid-discharging-head executes a first control in which an apex of a liquid surface is drawn into the second-nozzle-portion in a state in which an inner wall surface of the first-nozzle-portion is covered by a liquid film by decreasing the pressure inside the liquid chamber, and a second control in which a shape of the apex of the liquid surface is inverted to a protruding shape towed the opening and the droplet is discharged from the nozzle by increasing the pressure inside the liquid chamber in a state in which the inner wall surface is covered by the liquid film.