Using the Website

Project Page

The Project Pages were created in an effort to help promote student projects. The Project Pages provide a showcase where employers, other students, and friends can see what UIUC students are capable of. Many employers, in particular, consider a good Senior Design Project to be just as valuable as internship experience. The Project Pages will develop over time into a valuable library of practical engineering knowledge. Some of the best projects will be identified each semester and placed in the Senior Design "Hall of Fame," while the rest will be accessible by semester and search engine.

Updating Project Information

Once your project has been approved on the discussion board by the Instructor, you should promptly update your project information. In order to do so, find your project on the Project page, and click its title. When a frame expands, click on "Edit." Next, enter your UIUC netid and password. The system will lookup your project and prompt you for information such as your project's title. Please fill in the information that you wish to have appear for your project, and then click on the submit button. The required fields are marked so. You can update this information at any time. We strongly urge you to keep a backup of all of the information, and we would like to caution you of one scenario in particular. If multiple people attempt to edit this information at the same time, the second person to submit the changes will overwrite the first person's changes. Also, be sure to logout when you are done by closing the web browser. It is important that you provide a project desciption. It should be a brief overview of your project and explanation of why it is worth doing. Please provide this information as soon as possible and try to limit the length to about 250 words.

Submit Schedule

After updating your project information, you should proceed to the Submit Schedule page. Here each student should submit his/her schedule so that your TA can schedule a weekly meeting time. We know that there are a lot of boxes to check, but we need this detailed information because of how difficult it is to match schedules. The information is displayed in a convenient way for TAs when it is time for them to schedule meeting times. The system is very intuitive so instructions are not needed. NOTE: Please be sure that the schedule you submit is as accurate as possible, since you won't be able to edit it later!

After submitting your schedule, you should familiarize yourself with the "Upload Files" page.

Uploading Files

This area is used to upload files such as the Proposal, the Final Paper, Images, and additional files. When a file is uploaded, it is renamed and limited to a specified size. Special documents such as Proposals and Final Papers should be uploaded into the appropriate slot and will automatically be added to your Project Page. Images and other files can be uploaded into any other slot such as "file1." To upload a file, simply select which slot to place it in, and then select the file from your computer using the "Browse" button.

Instant Nitro Cold Brew Machine

Danis Heto, Mihir Vardhan

Instant Nitro Cold Brew Machine

Featured Project

# Instant Nitro Cold Brew Machine

Team Members:

- Mihir Vardhan (mihirv2)

- Danis Heto (dheto3)

# Problem

Cold brew is made by steeping coffee grounds in cold water for 12-18 hours. This low-temperature steeping extracts fewer bitter compounds than traditional hot brewing, leading to a more balanced and sweeter flavor. While cold brew can be prepared in big batches ahead of time and stored for consumption throughout the week, this would make it impossible for someone to choose the specific coffee beans they desire for that very morning. The proposed machine will be able to brew coffee in cold water in minutes by leveraging air pressure. The machine will also bring the fine-tuning and control of brewing parameters currently seen in hot brewing to cold brewing.

# Solution

The brew will take place in an airtight aluminum chamber with a removable lid. The user can drop a tea-bag like pouch of coffee grounds into the chamber along with cold water. By pulling a vacuum in this chamber, the boiling point of water will reach room temperature and allow the coffee extraction to happen at the same rate as hot brewing, but at room temperature. Next, instead of bringing the chamber pressure back to atmospheric with ambient air, nitrogen can be introduced from an attached tank, allowing the gas to dissolve in the coffee rapidly. The introduction of nitrogen will prevent the coffee from oxidizing, and allow it to remain fresh indefinitely. When the user is ready to dispense, the nitrogen pressure will be raised to 30 PSI and the instant nitro cold brew can now be poured from a spout at the bottom of the chamber.

The coffee bag prevents the coffee grounds from making it into the drink and allows the user to remove and replace it with a bag full of different grounds for the next round of brewing, just like a Keurig for hot coffee.

To keep this project feasible and achievable in one semester, the nitrogenation process is a reach goal that we will only implement if time allows. Since the vacuum and nitrogenation phases are independent, they can both take place through the same port in the brewing chamber. The only hardware change would be an extra solenoid control MOSFET on the PCB.

We have spoken to Gregg in the machine shop and he believes this vacuum chamber design is feasible.

# Solution Components

## Brewing Chamber

A roughly 160mm tall and 170mm wide aluminum chamber with 7mm thick walls. This chamber will contain the brew water and coffee grounds and will reach the user-set vacuum level and nitrogenation pressure if time allows. There will be a manually operated ball valve spout at the bottom of this chamber to dispense the cold brew once it is ready. The fittings for the vacuum hose and pressure sensor will be attached to the screw top lid of this chamber, allowing the chamber to be removed to add the water and coffee grounds. This also allows the chamber to be cleaned thoroughly.

## Temperature and Pressure Sensors

A pressure sensor will be threaded into the lid of the brewing chamber. Monitoring the readings from this pressure sensor will allow us to turn off the vacuum pump once the chamber reaches the user-set vacuum level. A temperature thermocouple will be attached to the side of the brewing chamber. The temperature measured will be displayed on the LCD display. This thermocouple will be attached using removable JST connectors so that the chamber can be removed entirely from the machine for cleaning.

## Vacuum Pump and Solenoid Valve

An oilless vacuum pump will be used to pull the vacuum in the brewing chamber. A solenoid valve will close off the connection to this vacuum pump once the user-set vacuum pressure is reached and the pump is turned off. To stay within the $100 budget for this project, we have been given a 2-Stage 50L/m Oil Free Lab Vacuum Pump on loan for this semester. The pump will connect to the chamber through standard PTFE tubing and push-fit connectors

If time allows and we are able to borrow a nitrogen tank, an additional solenoid and a PTFE Y-connector would allow the nitrogen tank to connect to the vacuum chamber through the same port as the vacuum pump.

## LCD Display and Rotary Encoder

The LCD display allows the user to interact with the temperature and pressure components of the brewing chamber. This display will be controlled using a rotary encoder with a push button. The menu style interface will allow you to control the vacuum level and brew time in the chamber, along with the nitrogenation pressure if time allows. The display will also monitor the temperature of the chamber and display it along with the time remaining and the current vacuum level.

# Criterion For Success

- A successful cold brew machine would be able to make cold brew coffee at or below room temperature in ten minutes at most.

- The machine must also allow the user to manually control the brew time and vacuum level as well as display the brew temperature.

- The machine must detect and report faults. If it is unable to reach the desired vacuum pressure or is inexplicably losing pressure, the machine must enter a safe ‘stop state’ and display a human readable error code.

- The reach goal for this project, not a criterion for success, would be the successful nitrogenation of the cold brew.

Project Videos