---
# System prepended metadata

title: Flow Control Challenge

---

## Testing the Flow
In order to test water tight compression of feed parts and the according flow rate, three simple test runs of 10 minutes were made for tank levels of 2 cm, 1 cm and 0,5 cm.  

{%youtube Vep-4BQy_eo %}

## Results
time in min | water level height (Feed tank) in mm | captured water in ml |
|:---:|:---:|:---:|
| 10     | 20 | 140 |
| 10 | 10 | 100 |
| 10 | 5 | 55 |

![](https://hackmd.io/_uploads/rk6fcfN92.png)


## Findings
- The force of the compression seems to have a massive effect on the flow rate. In the beginning, it was only when I loosened the compression a little that the wicks started to soak.
- Tiny gaps in the sealing occur at the edge areas of the wicks, resulting in slight leaks.
Drops form on the underside of the feed and run down the sides of the plates, possibly causing contamination.

{%youtube qieSYLvFLD0 %}



## Notes 

The aim is for the edge areas of the feed parts to be flush and watertight. 
![](https://hackmd.io/_uploads/SJRsGmN9h.png)

The sealing should not create any extra distance between the parts.
![](https://hackmd.io/_uploads/HJfUmXE5n.png)

The middle area needs a recess in the material thickness of the wicks. At 100 % compression, a sufficient amount of water must still be able to flow through. 

![](https://hackmd.io/_uploads/H1J5GXV52.png)


---


## List of Requirements

Here, the aspects of the holistic design approach applied to the prototype version are listed. This helps to ensure high quality development of Open Source Hardware and improves transparency and documentation.
> You don't need to be familiar with every aspect, but find the ones you are an expert in and check how they relate to other design decisions.


|  | Priority | Description | Comment/number | Source |
|:---:|:---:|:---|:---|:---|
|   Objective    |  A  | A self-regulating water flow reduces the complexity and the need for monitoring or high-tech sensor + control systems. | The effect of clogging and salt formation on the feeding system. #Maintenance circles |  |
|    Geometry    |  A  | Funtioning principles of Vertical Multiple-Effect Distillation (VMED)| e.g. highest efficiency with 5-8 mm distance between stages, but ensure no contamination   |https://www.sciencedirect.com/science/article/pii/S0011916422000273 |
| |  A  | Modular components | the product allow for modular upgrades or repairs |   |   |   |
| |  B  | modular expansion of the system | The system is scalable up to 8 Acraea modules to clean around 100 liters a day |  |  |  |
| Forces |  A  | Compression of the individual feed parts | The force needed for wing nut screw mechanism |  |  |  |
| | C | Expansion of heated materials under compression | Does material expansion affect functionality? Can it be used to regulate flow? |  |  |  |
|  Ergonomics |  A  | Compression of the individual feed parts | Counter-holding thumb and index finger (screwing) |  | DIN EN ISO 26800 |   |
|  Material |  A  | Durability | Resistant to intervalls of heat and environmental conditions|   |   |   |
|  |  C | Bio-based, regenerative | Not only reducing and compensating -> give back to the system  |  |   |   |
| Safety | A | Food safe | ensuring food safety is essential, 3D printed parts need extra attention | https://formlabs.com/de/blog/leitfaden-lebensmittelechtheit-3d-druck/ |
| | B | High temperature of heat source | Temperature display or secured commissioning |     |  |
| Transport | A | Local availability | Prioritize regional resource streams |  |  |  |
| |  A  | Low impact procurement and deployment | Can be measured with Life Cycle Assessment |   | 
| Usage |  B  | Accessibility according to frequency | User-friendliness of the most frequently used components |    |   |
| |  A  | Durability | Economic and ecological selection of materials and production according to the number of uses (dis-/assembly) |  |  |  |
|  Circularity   |    B     | Reuse & Recycle  | 
| Maintenance | A | Method + frequency  | tbd. |
| | B | Usability | Easy to understand and operate (user-friendliness) |
| Identification | A | Easy identification of components and parts for documentation & assembly | Prusa provides good example | [Printed parts versioning](https://help.prusa3d.com/guide/1-introduction_63488) |
| | A | Easy identification of materials for separation/reuse| e.g. standardized embossing for plastics | ISO 11469:2016
| Manufacturing | A | open access production technology| euqipment of makerspaces such as 3D printers, CNC, laser cutters, sewing machines, woodworking and metalworking tools, electronic tools |
| | C | regional industry | value creation with local stakeholders in contribution to circular solutions |




