Mechanical Compressor Steam Dryer for Paper Web Drying
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Solution Overview
Problem
Current steam dryer devices for paper, board, or pulp webs are limited by the available steam pressure, which restricts the upper temperature of blowing air, and existing technologies like steam ejectors are inefficient and costly in terms of power consumption and pressure rise.
Innovation Solution
A steam dryer device utilizing a mechanical compressor to increase low-pressure steam pressure, allowing flexible steam supply by bypassing the compressor and incorporating a desuperheater to maintain efficient heat transfer, with the option to use an intercooler for improved compressor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a steam ejector is used to raise steam pressure, then steam pressure is increased, but power consumption is high and pressure rise is limited
Solution Approach 1:
The patent replaces the steam ejector (a thermal device using steam expansion) with a mechanical compressor that directly mechanically compresses the steam. This substitution enables higher pressure rise ratios and better energy efficiency by using mechanical work instead of thermal energy conversion, directly resolving the contradiction between achieving high steam pressure and minimizing power consumption.
2Productivity
If available steam pressure is limited, then drying capacity is restricted, but increasing steam pressure requires inefficient equipment
Solution Approach 1:
The mechanical compressor enables significant steam pressure increase that was not achievable with steam ejectors, directly breaking the limitation on drying capacity. By using mechanical compression, the system can operate at higher steam pressures that correlate with higher drying capacity while maintaining energy efficiency.
Solution Approach 2:
The patent changes the key parameter of steam pressure from low/limited values to high values through mechanical compression. This parameter change directly increases the drying capacity of the dryer system, as higher steam pressure enables more effective heat transfer and higher operating temperatures in the drying process.
3Productivity
If high pressure steam is used continuously, then drying capacity is maximized, but energy consumption increases
Solution Approach 1:
The patent implements a dynamic system where the mechanical compressor can be adjusted or bypassed based on demand. The control system allows switching between compressor operation and bypass modes, enabling the system to optimize between high drying capacity (compressor on, high pressure steam) and energy saving (compressor off, bypass active) conditions, thus resolving the contradiction between continuous high productivity and energy consumption.
Solution Approach 2:
The system allows periodic or intermittent operation of the mechanical compressor rather than continuous operation. The bypass line enables the system to alternate between using compressed high-pressure steam and using direct low-pressure steam, creating a periodic action pattern that balances drying capacity requirements with energy consumption, allowing the compressor to run only when high drying capacity is needed.
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 mechanical compressor provides a cost-effective and efficient high-pressure steam supply, increasing drying capacity and reducing power consumption, while allowing for adaptable steam pressure based on demand, suitable for both new and existing pulp and paper dryers.
Implementation Method 1
a mechanical compressor (2) for increasing the pressure of the low pressure steam
Implementation Method 2
a desuperheater (4) for cooling the steam, wherein the desuperheater (4) is arranged between the mechanical compressor (2) and the dryer (3)
Data Source
Figure 1
AI summary
An improved steam dryer device for paper, board or pulp webs is disclosed. The steam dryer device comprises a low pressure steam source (1) for generating low pressure steam, a mechanical compressor (2) for increasing the pressure of the low pressure steam, and a dryer (3) for drying the paper, board or pulp web using the steam from the mechanical compressor (2). The invention also regards to a respective method.