Spray Chamber Design for Paper Web Coating
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Solution Overview
Problem
Existing spraying devices for applying liquid coatings on paper webs suffer from unwanted deposition and accumulation of the liquid product on the inner surfaces of the spray chamber, necessitating frequent cleaning operations.
Innovation Solution
A spraying device with a spray chamber delimited by a moving paper web guided by parallel guide rollers and multiple spraying nozzles arranged to minimize exposure of the liquid product to non-paper web surfaces, using a rotary support with adjustable nozzles and a cleaning system to reduce accumulation and facilitate cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a spray chamber with fixed walls is used to spray liquid product onto paper web, then the liquid product can be effectively applied to the paper web, but the liquid product accumulates on the inner surfaces of the spray chamber walls requiring frequent cleaning
Solution Approach 1:
The spray chamber walls are replaced with movable guide rollers that can adjust their position. The paper web itself becomes a dynamic boundary that moves through the spray chamber, eliminating static surfaces where liquid accumulation occurs. The guide rollers can be repositioned to accommodate different paper web widths and maintain optimal spray geometry.
Solution Approach 2:
The moving paper web serves as its own containment boundary, defining the spray chamber volume through its passage between guide rollers. The web's continuous motion prevents liquid product from accumulating on chamber surfaces, as the chamber is effectively reconfigured with each pass of the web.
2Area of stationary object
If multiple spray nozzles are installed in the spray chamber to cover the paper web width, then complete coverage is achieved, but the complexity of the device increases
Solution Approach 1:
The spray system is divided into multiple independent nozzle units that can be individually positioned and adjusted. Each nozzle covers a specific section of the paper web width, and the guide rollers are segmented to allow independent adjustment of each section's position and angle for optimized spray coverage.
Solution Approach 2:
The guide rollers serve multiple functions: they guide the paper web through the spray chamber, define the spray chamber boundaries, provide mounting positions for the spray nozzles, and enable adjustment of spray angles and coverage areas. This multi-functionality reduces the need for separate components for each function.
3Reliability
If the spray chamber is enclosed with fixed walls to contain the spray, then spray direction is controlled, but cleaning operations become necessary due to liquid accumulation on walls
Solution Approach 1:
The fixed enclosed walls are replaced with dynamic guide rollers that follow the paper web's path. Spray direction is controlled by the positioning and angling of these rollers relative to the moving web, maintaining reliable directional control without creating static accumulation surfaces that require cleaning.
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
Minimizes unwanted deposition and accumulation of the liquid product, reducing the need for frequent cleaning and ensuring efficient application of coatings on the paper web while allowing for adjustable nozzle positioning and cleaning.
Implementation Method 1
A plurality of spraying nozzles is installed inside the spray chamber and said nozzles are connected to a liquid product supply source and oriented so as to direct the sprayed liquid product towards the opening across the spray chamber in order to spray the liquid product onto a surface of the moving paper web
Data Source
AI summary
The spraying device for spraying a liquid product onto a paper comprises spraying nozzles (1) connected to a liquid product supply source and arranged in a spray chamber (3) to spray the liquid product onto a moving paper web (2) guided by guide rollers (6), where the spray chamber (3) is delimited in part by the moving paper web (2), and at least one of the guide rollers (6) is located inside the spray chamber (3). In one embodiment, the spraying nozzles (1) are arranged in a rotary support (7) including a tubular wall (7a) with a longitudinal opening (4), and the spray chamber (3) is delimited only by sections of the paper web (2), portions of the tubular wall (7a) adjacent to the longitudinal opening (4), and side walls (5).