Modular Floating Cover for Digestate Tanks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cover systems for large storage tanks, particularly those handling organic substrates and viscous fluids, face issues with gas accumulation, corrosion, and uncontrolled emissions due to high viscosity and seasonal discharge patterns, leading to safety concerns and maintenance challenges.
Innovation Solution
A modular floating cover system with a waterproof membrane, reinforced nonwoven fabric, and a dedicated rainwater management system, which limits gas accumulation, prevents malodorous emissions, and ensures structural integrity and accessibility, using materials resistant to corrosive environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed cover system is used for large storage tanks, then gas accumulation is prevented, but the system becomes vulnerable to corrosion and structural integrity issues under high viscosity and seasonal discharge patterns
Solution Approach 1:
The cover system is divided into multiple modular floating elements that can independently move and adjust. This segmentation allows the cover to better adapt to viscous fluid dynamics and seasonal discharge patterns, reducing stress concentration and corrosion risk on any single element while maintaining overall structural integrity.
Solution Approach 2:
The cover transitions from a fixed structure to a dynamic floating system that can move with the liquid level and adapt to varying viscosity conditions. The modular floating elements respond to seasonal discharge patterns and high viscosity stresses, preventing structural failure and corrosion by distributing mechanical loads dynamically.
2Adaptability or versatility
If a floating cover system is used, then adaptability to liquid level variations is improved, but gas accumulation and uncontrolled emissions occur due to high viscosity and seasonal discharge patterns
Solution Approach 1:
The cover employs flexible waterproof membrane material that can conform to the varying liquid surface while maintaining gas tightness. This flexible shell approach allows the cover to adapt to liquid level changes and viscous fluid dynamics without creating gaps that would lead to gas accumulation and uncontrolled emissions.
Solution Approach 2:
The cover system uses composite construction combining floating elements, waterproof membranes, and reinforcement layers. This composite structure provides both the flexibility needed to adapt to liquid level variations and the gas tightness required to prevent biogas accumulation and malodorous emissions under high viscosity conditions.
3Reliability
If materials resistant to corrosive environments are used, then reliability is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The cover system uses modular floating elements made from materials that provide adequate corrosion resistance for the intended service life, balancing durability with manufacturing simplicity. The modular design allows individual elements to be replaced if needed, reducing the need for overly complex corrosion-resistant materials throughout the entire structure.
Solution Approach 2:
The waterproof membrane uses flexible material that provides inherent corrosion resistance while remaining relatively simple to manufacture and install. This thin film approach achieves reliable corrosion protection without the complexity of thick metal structures or complex protective coatings.
4Volume of stationary object
If the cover system is designed for large tank diameters, then storage capacity is improved, but stress concentration occurs at discharge outlets leading to structural failures
Solution Approach 1:
The cover is segmented into multiple modular floating elements distributed across the large tank diameter. This segmentation prevents stress concentration at any single location, including discharge outlets, by distributing mechanical loads across many independent elements while maintaining overall storage capacity.
Solution Approach 2:
The modular design allows different regions of the cover to have optimized properties for their specific functions. Elements near discharge outlets can be designed with enhanced local strength or different structural characteristics to handle concentrated stresses, while other areas optimize for overall coverage and buoyancy.
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 system effectively reduces gas storage volume, recovers biogas, prevents uncontrolled emissions, and ensures safety by maintaining a vacuum environment, while being adaptable to varying liquid levels and temperatures, with easy maintenance and scalability for different tank sizes and shapes.
Implementation Method 1
a floating raft (20) formed by a plurality of modular floating elements (21) connected one to the other at restraining joints (22) so as to form the tank cover
Implementation Method 2
a cover element (10) comprising a cover layer (10) comprising a membrane (11) in waterproof fabric, suitable for containing the biogas that may be generated
Implementation Method 3
said membrane (11) in waterproof fabric being distended by means of a tensioning system (12) configured to distend said fabric membrane (11)
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
The present invention relates to an active floating cover system for physically covering tanks and/or vessels for storing digestate and/or organic matrices for seasonal use or even only subject to the release of compounds which may cause olfactory nuisance and/or emissions of volatile compounds (such as, for example, H2S, NH3, CH4) potentially harmful to the environment, with the simultaneous possibility of conveying and removing rainwater. More particularly, the present invention relates to a floating cover system, made at least in part in plastic material, chemically inert to volatile compounds and to the matrices stored, for the covering of tanks used especially, but not exclusively, in the area of processes of anaerobic digestion of organic substrates, and in particular for tanks for the storage of the digestate obtained from the process. In this application, in fact, the aforementioned conditions, the organic nature of the material stored, the seasonal use of the same (which entails sudden fluctuations in level), the potential release of volatile compounds with a high odorous impact, as well as adverse weather conditions, occur simultaneously.