Prototype Doser Frame
Rough draft. Matt, this is ready to be reviewed but I have not yet given it a thorough look over and the drawings have not yet been imbedded. I plan on two views of the proto-type that will give a good view of all the components and how they will work.
Abstract
A full scale proto-type is being created. This model will allow was designed and built. It was built to scale to represent the alum doser as it is positioned in the entrance tank of an Agua Clara water treatment plant. The model allows us to run full flow/ full scale accuracy tests in the lab. Additionally, this the model will be taken to the EP3 conference this spring. With this proto-type we will be able to demonstrate the functionality and flexibility of our chemical doser.
Proto-type Design
The proto-type is made up comprised of two main componentcomponents: the structural frame work and the moving lever-arm. All components will be fabricated The frame components are constructed using a modular aluminum framing system manufactured by a company called 80/20 Inc. Affectionately called "The Industrial Erector Set," this company offers a wide variety of components along with an a down-loadable Auto-cad plug-in of each of their components. With these tools, we have been able to design and evaluate multiple proto-types. Additionally, their the T-bar design will allow of the framework extrusions allows us to mount extra components that can be mounted with a any standard "National Course" thread. All accessories are readily available and are purchased through McMaster-Carr.
The dimensions of the structural framework is designed with the same dimensions as are based on the actual dimensions of the entrance tank except the actual tank measures 1 meter x 1 meter and our framework is 1 meter by ½ meter. This was done only as a space saving measure. The height of our framework however is the same as the height of the entrance tank. Entrance tanks dimensions are based off the relationship between the design flow rate through the plant and the headlosses within the plant and across the rapid mix tube. Additionally, we need to accommodate the length of the rapid-mix tube and approximately 10 inches of free board. The actual values and results from these calculations are included elsewhere in this document but concluding, the height of the entrance tank and therefore our prototype is ***** meters high.of the Agalteca plant. We have reduced the width to 1/2 meter as a space/material-cost saving measure but otherwise accurately reflect the entrance tank dimensions. Entrance tank dimensions and elevation are a critical criteria in plant operations. Head losses throughout the plant must be accounted for in the entrance tank. Furthermore, the addition of the physical parameters of the rapid-mix tube have added to the depth of the entrance tank. Full analysis of these parameters can be found on the Agalteca Page
The frame work also In addition, the frame work includes a table to hold a small stock tank and another table to hold the constant-flow device. As head tank. Ideally, as determined in the design of the constant-head devicetank, there should be ideally 30 cm between the orifice and the low water lever of the stock tank. This dimension has been taken into account in our design. Figures 1.0 - 1.2 illustrate our prototype from various views and a full description of each component follows.
We have designed three different lever systems with the current-final lever presented here.
!prototype1.JPG!There are a number of constraints in the design of this lever arm. First, we need to facilitate a way to attach the floats and counter-weight. Secondly, we must have a way to adjust the distance the orifice travels down the arm. It was also requested that the operators be given a means to manually "shut off" the flow. This can be accomplished by moving the orifice directly in line with the pivot. We have also attempted to accommodate a second slide to facilitate attaching a second dosing pH control system. It is preferred to both slides on the same side of the lever to allow the operator easier access.
As shown in our current design, most of these constraints can be met. We are using a slide mechanism that has a manual "brake" which allows the slide to be clamped in any position. We have not found a way to get both slides on the same side of the lever arm as their "open channel dosing tubes" would interfere with each other. Currently, the slides are on opposite sides and could be awkward for the operator to manipulate. However, each slide can be moved independently and can be moved to the center line to allow the operator to secure flow if needed. The floats and weights will be attached via the brackets at the endpoints.
A material list is being created which lists each of these components, part number, quantity, catalog page number, price and associated fasteners. This material list needs to be updated to reflect our most recent design once this design has been approved by all members of the team. Also, in creating this list we found that some of our selected components were disproportionately expensive and modifications are being done to the frame to accommodate less expensive brackets. These are small modifications and the design is near ready to be sent out for pricing and the components will be ordered. Upon arrival of the parts, we will be able to build our full scale model, attach the hydraulic components and begin testing.
BLah - ignore the stuff written below, it's part of the template
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- (Who is working on this, approximately when will they work on it?)
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- (Who is working on this, approximately when will they work on it?)
Fig 1.0 Isometric View
Fig 1.1 Top View
Fig 1.2 Side View
Components
Lever Arm
The lever arm is a 1" x 1" T-slotted aluminum-extrusion bar as classified by 80/20 Inc. as 1010. The length of the lever arm is a critical dimension for Alum dosing and is calculated in the Dual Scale Child page. This length of 0.80 meters accounts for the variation in the water level of the entrance tank resulting from changes in plant flow. The lever arm is attached the pivot rod with a clamp which is then attached to two side bearings on the frame. The accessories were purchased through McMaster Carr. The lever is positioned in such a way that the slide can be positioned directly under the pivot providing a manual shutoff.
Slide
The slide is a component from 80/20 Inc. (Part # 6730) that we attach the orifices to. There is also a hand brake that is attached.
Brake
Fig 1.3 Slide and Brake
The brake keeps the slide in place, also a component from 80/20 Inc. The brake naturally keeps the slide in place, while pushing on the area shown on the diagram relieves the pressure and allows for the movement of the slide
Float and Counter-Weight Connectors
Also shown in Figure 1.0 are the eyebolts that will be used as attachment points for the float and counter-weight (should we decide to use one). These items will be attached using mono- filament fishing line.
Stock Tank
The stock tank will sit on the triangular table that is pictured. The table for the stock tank is 24.13 cm (9.5 inches) tall to provide enough head to demonstrate how our system works.
Constant Head Tank
The constant head tank is maintained on this platform. The platform is adjustable by loosening the attachment points to allow accurate leveling. This is a critical height as the water level in this tank must be in line with the orifice when the lever-arm is horizontal.
The AutoCad Drawing can be viewed Here
h.3 Assembled Prototype
The prototype was assembled and hydraulic components attached. The following two drawings show the assembled structure and key components are labeled.
Useful 80/20 information
80/20 Inc. is a manufacturer of modular aluminum framing system. 80/20 components are used extensively throughout our lab and specifically in this project. This section provides some details to assist getting started with these components and using them in design.
http://www.8020.net/; This is the main web page for this company. Available is a complete on-line catalog, price catalog and design ideas. Design is made easier using their "Auto-cad Plug-In." All components and frames are available with this Plug-In requiring only limited Auto-cad knowledge for a professional looking design.
This Plug-In, called Auto-Quoter, is used by the distributors to generate a price-quote. Auto-Quoter can be downloaded on to any computer that is running Auto-cad and is free. This program leads to greater accuracy when ordering and less chance of error as the Bill of Materials is generated directly from the Auto-cad drawing.
Two local distributors are:
Ralph W. Earl Inc.
5930 E.Molloy Rd.
Syracuse NY 13220
315-454-4431
rwearl@rwearl.com
Specifically- Bob Prosher:bproscher@rwearl.com. Competent and helpful salesman.
Hughes Industrial
9685 Main St.
Clarence NY 14031
800-759-8374
www.hughesind.com
Ordering Information
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Bill of Materials.pdf as generated by the AutoQuoter program and is attached. Bob Proscher from Ralph W. Earl Inc was able to procure a 40% discount for us on materials. The order for these components was submitted to Christene Day on November 17,2009 and parts were received on November 30, 2009. We are currently waiting on receipt of the materials to continue on the project.
Bibliography
- http://www.8020.net/Default.asp Includes parts catalog, pricing list and Auto-cad Plug in
Deliverables
By the end of the semester we intend to have a functional, full scale non-linear chemical doser. In order to accomplish this, this sub-group needs to complete the following:
* Complete final changes to Autocad drawing to represent changes in the bracketing.
* Talk to Paul Charles about fabrication of the bushing and drilling of the lever-arm
* Update Material's List
* Contact 80/20 distributor about pricing. Plan to discuss the possibility of having them sponsor our frame
* Order and receive components. Assemble according to Autocad Dwg.
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All semester goals were met concerning this aspect of the project and are summarized below:
- Proto-type was designed. Autocad drawing created
- Components ordered and received.
- Model assembled
- Hydraulic components attached including orifice, clip, stock tank and constant-head tank.
Outstanding
- As this is a model of what will ultimately be used in Honduras, the assembled model needs to be fully evaluated for ease and practicability of use. Additionally, components for the Honduran doser need to be purchased. Once accomplished, a full doser material list will be added to the wiki.