Rotary Desiccant Dryer Pressure Control to Prevent Dew Point Peaks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas dryers face issues with dew point peaks and inefficient energy use, particularly when starting up, due to insufficient pressure in the drying zone and potential gas leaks from the regeneration zone to the drying zone.
Innovation Solution
The implementation of a blower to boost the second regeneration flow, ensuring a higher pressure at the drying zone outlet than the regeneration zone inlet, combined with a non-return valve and a heating element to maintain optimal humidity levels and prevent leaks, along with a control system to manage pressure differences and rotational speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gas flow rate through the regeneration zone is increased to improve regeneration efficiency, then the drying agent is regenerated more effectively, but the pressure in the drying zone decreases causing gas leaks from the regeneration zone to the drying zone
Solution Approach 1:
The gas flow is segmented into two separate flows: a first regeneration flow through the first subzone and a second regeneration flow through the second subzone. This segmentation allows independent control of each flow's characteristics and pressure, enabling the second flow to be boosted to maintain pressure differential and prevent leaks while the first flow provides effective regeneration.
Solution Approach 2:
A blower is introduced as an intermediary device to boost the second regeneration flow. This blower acts as a mediator that increases the pressure of the second regeneration flow without affecting the first regeneration flow, thereby maintaining the pressure differential between zones and preventing gas leaks while ensuring adequate regeneration.
2Reliability
If a blower is added to boost the second regeneration flow to prevent gas leaks, then pressure differential is maintained, but device complexity increases
Solution Approach 1:
The second regeneration flow is taken from the dried gas outlet, allowing the system to use its own processed gas to regenerate the drying agent in the second subzone. This self-service approach reduces the need for external compression equipment while maintaining the necessary pressure differential and preventing gas leaks.
Solution Approach 2:
The blower serving the second regeneration flow is designed to perform multiple functions: it boosts the regeneration flow, maintains pressure differential, and can be integrated with the existing drum rotation control. This multi-functionality reduces the need for separate dedicated components for each function.
3Productivity
If the drum rotation speed is increased to improve drying efficiency, then more gas can be processed, but the contact time between gas and drying agent decreases reducing drying effectiveness
Solution Approach 1:
The drying process is segmented into two distinct zones: a first subzone for regeneration and a second subzone for drying. This segmentation allows the drum to rotate continuously while gas flows through both zones sequentially, enabling high productivity through continuous operation while maintaining adequate contact time in each zone for effective drying and regeneration.
Solution Approach 2:
The rotating drum enables continuous operation where the drying agent is constantly cycled between the regeneration subzone and the drying subzone. This continuous action allows the system to process gas at high rates without interruption, while each portion of the drying agent maintains sufficient contact time with the gas in both zones for effective drying and regeneration.
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
This configuration ensures deep drying of the gas, maintains high dryer efficiency, and prevents dew point peaks, enhancing operational reliability and energy efficiency across various conditions.
Implementation Method 1
The moist gas leaving the regeneration zone is then guided through a cooler in the connecting pipe such that the temperature of this gas falls to below the pressure dew point and condensation of the moisture in the gas occurs.
Implementation Method 2
the drying agent extracts moisture from this compressed gas by means of sorption (adsorption and/or absorption)
Implementation Method 3
combined with a non-return valve and a heating element to maintain optimal humidity levels and prevent leaks
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Dryer that is provided with a pressure vessel (2) with a drying zone (3) and regeneration zone (5); whereby the regeneration zone (5) comprises a first subzone (6) and a second subzone (7); whereby the dryer further comprises a rotatable drum (9) in the pressure vessel (2) with a drying agent (8), whereby the outlet of the regeneration zone (5) is connected to the drying zone (3) via a connecting pipe (13) with a cooler (15) and condensate separator; whereby a tap-off pipe (17) is connected outlet of the drying zone (3) and is also connected to the inlet of the second subzone (7); and whereby a blower (19) is provided to realize a regeneration flow from the drying zone (3) to the second subzone (7).