Debaler Instrumentation and Data collection

The goal of the project is to build upon and add to the previous debaler prototype from 2019-2020 school year. We will achieve this by making the debaling process automated by adding an inlet conveyor system capable of carrying 2 bales towards the debaling head, while also integrating a working control system to control the material outflow and will also be able to detect bale jamming/motor stall and correct with no human interaction. By the end our project the debaler should be able to have a bale successfully debaled at a consistent flow for a specified flowrate without any human input other than the loading of the bale.

=Problem Definition= The current debaler prototype is not an automated process, and the main goal from the client is to make the current prototype an automated machine. This requires adding an infeed conveyor to the current processing head, a working control algorithm to detect bale jams, and chute clogs also need to be added to this system. Additional improvements to the prototype such as cleaning off the processing head and making sure all loose (debaled) material goes through the chute are also desired by the client. Testing and data analysis of the system running different types of materials is also required.

Background
As the need for precision agriculturally based feedstocks for biofuels and bio-based products increases, there is a need to debale straw, corn stover, hemp stalks, and other baled herbaceous crops for feeding into industrial processing equipment. The fundamental question is how can we effectively and efficiently turn baled material back into the loose material it was baled from and feed it onto a conveyor for subsequent milling and processing? Existing debalers were developed to support dairies and feedlots where the objective is only to distribute the material in small enough “chunks'' for cows and other animals to eat. Existing methods either do not break apart the flakes well or create a large amount of fines in the process. Forest Concepts needs a debaling mechanism to break down large square bales of stover, switchgrass, and similar materials into uniform streams that can be conveyed into our Crumbler® rotary shear comminution systems.

Deliverables
Our goal is to use available materials and scrap parts to improve the mechanical design, saving our financial resources to develop a control system to sense and correct bale jamming or chute clogs, and monitor the outflow of material. From the testing of various agricultural material we will document recommended operating parameters based on material type.

Specifications
1.	Mechanical device to pull apart and fluff baled agricultural materials 2.	Control algorithm to sense and correct bale jamming 3.	Consistent outfeed of material 4.	Easily transportable by standard highway equipment 5.	Prototype to withstand up to 140 lb bales 6.	Conveyor infeed system able to automatically transport bale to processing head

=Design Considerations= This project was a design continuation from the previous year’s capstone design. At the beginning of the project, it was decided to continue the previous team’s work instead of trying to start from scratch. Therefore, some of the main design elements, such as the processing head, were not reconsidered.

Infeed Conveyor

After an old hay elevator was sourced to be used as the infeed conveyor, the angle at which it would feed into the processing head would have to be chosen. Three angles were discussed, the first being horizontal to the ground, angled from the ground up to the processing head, and finally angled down into the processing head.

Horizontal Angle

Pros:

-Will not have to contend with gravity

-Will not have to redesign processing head stand -Conveyor stand will be simple to build

-Easy to adjust distance between conveyor and processing head after installed

-How existing prototype was built to operate

Cons:

-Will have to lift bale to conveyor

Ground to Processing Head

Pros:

-Easy to load bale

-Will not have to redesign processing head stand

Cons:

-Hard to keep bale together while going up conveyor -Conveyor stand will be more difficult to build

-Hard to adjust distance between conveyor and processing head after installed

-Bale could fall back down conveyor

Down into Processing Head

Pros:

-Gravity assisted

-Easy to adjust distance between conveyor and processing head after installed

Cons:

-Will have to rebuild processing head stand -Difficult to load

-Conveyor stand will be very large and difficult to build

Head Cleaning

During the testing of the previous prototype, it was noted that the hay seemed to wrap around the tines on the processing head instead of falling off after being torn from the bale. This in turn would make a mess flipping hay to places it was not intended to go. To solve this problem two possible solutions were discussed: attaching brushes to the processing head that the fingers would pass through and enclosing the entire processing head.

Brushes

Pros:

-Low cost

-Easily sourced

Cons:

-Initial testing did not yield satisfactorily results -Difficult to properly install

Sheet Metal Enclosure

Pros:

-Would contain any mess made

-Provides protection against spinning processing head

Cons:

-More expensive -Time intensive to create

Bale Jam Sensing

To complete the desired automation effect of limited touch operation, a bale jam sensing system will need to be implemented to ensure the proper function of the machine. To track the bale jamming, two methods were considered, Hall Effect sensors, and current overload on the previously installed VFD.

Hall Effect Sensor

Pros:

-Simple to code

-Low cost

Cons:

-Added failure points

-Added cost

-Only gives one data point

VFD

Pros:

-Already have equipment

-Reliable

-Provides more data

Cons:

-Complicated to program

=Project Learning=

=Final Design=

The Final design of our project was a machine that consisted of three main parts the Header, Infeed Conveyor, and Control system. We developed our final design from early testing and conceptual designs.

The header was part of the previous team’s prototype, and performs the main function of the debaler. The header has many finger-like tines that stick out from cross bars on a chain. These fingers spin around and pull through a bale to remove material and feed it into the outfeed chute. The previous teams prototype worked but we made a few improvements. For example, the original prototype could not contain debaled material cleanly. As the machine ran material would wrap around the tines and allow material to fall out the back and not into the outfeed chute. This can be seen in the figure below.

The new design of the Header includes a shroud that encases the Header and allows material to be funneled directly into the outfeed chute. The shroud also acts as a safety feature as well only having one face open and exposed to the turning Header tines. For ease of building and to make sure material did not jam in the shroud we chose to cover the whole Header including the turnbuckle that allows for angle adjustment. And since we want to be able to change the angle of the Header there is an access panel on the back of the shroud that allows for easy access.

During our initial testing we discovered that the original motor had little torque that allowed it to stall easy. So during testing when we thought a bale jam was occurring that was not always the case instead it was the motor stalling unable to keep spinning the header. So our last major change to the Header was adding a 1750 rpm 1.5hp motor with a 6 to 1 gear range to allow for plenty of torque.

Our main addition to the previous team’s prototype was the infeed conveyor. Since the previous design you had to manually push bales into the Header, we wanted to create a way to automate that. So, we came up with a way to use a conveyor system to transport bales to the Header. The solution we came up with was cheap and easy to implement. We were able to obtain an old hay elevator and cut it down to the size we needed. This allowed us to put together a system that functions on our relatively low budget. If we would have designed and built a conveyor by ourselves it would have been much more expensive and probably would have taken nearly the whole 2 semesters.

Since we replaced the old Header motor, we were able to reuse that motor to control the Conveyor. This was a great solution because this motor already had a VFD so the speed could be varied, and the direction could be reversed. Below you can see our Infeed conveyor system.

The final part of our system is our Control system. We first discussing the project with our client we were hoping to have a fully automated system, meaning one button push and everything runs. Sadly our final design did not consist of that. With none of the team members having experience with controls system we were unable to figure out how to get our system to work fully automated. But our design consists of 2 motors, 2 VFD’s, a double pole double throw switch, and 2 Emergency stops. Each VFD controls 1 motor, and the switch is used to control the Header. So, the switch is used to control forward, stop, and reverse of the Header. And in case of Emergency both E-stops need to be pressed to fully shutdown the machine. Our control board can be seen below.

=Validation=

=Team Members=

=Additional Documentation=

Project Schedule



Meeting Minutes

Presentations



Client Interview