Rationale Report

Introduction

            My partner and I are currently designing a water filtration system. I am working on the structural aspect of the system, while my partner is working on the filtration aspect, and so far four alternate solutions are available. The final solution chosen resulted from the design matrix constructed and shown below. Each alternate solution was ranked according to how the design met each specification. 

Design Matrix

 

Solution 1:

 

 

            Solution 1 is constructed entirely of polycarbonate because the material is strong but lightweight, durable and impact resistant. The polymer can withstand temperatures between -40° and 280° Fahrenheit. This solution is cylindrical in shape and has a screw on top, which encompasses the whole top of the structure. The exterior consists of a small handle on the lid so the device can be easily screwed on and off when pouring in water, two handles for carrying purposes, and a spout where the clean and filtered water exits.

            A pole runs through the center of the interior structure. This plastic pole is connected to the bottom of the container so that rod cannot be moved. This device supports the series of filters. On the middle and top of the rod there is a lip, which holds up a polycarbonate base. Both bases sit on the lip of the rod and have a series of small holes where water enters the filters and then exit. The bottom base separates the filters and clean water. The top base disperses water evenly throughout the surface of the filters.

            Pros include that the polycarbonate material is durable, yet lightweight and as a result the system will be easily portable. Due to the large screw on lid, the bases and filters can be easily taken out, cleaned, and replaced. Cons include that depending on how heavy the filters end up being, the lip of the rod may not be strong enough to steadily hold up all the filter materials.

Solution 2:

 

            Solution 2 is also constructed entirely of polycarbonate for the same reasons: the material is strong, durable, impact resistant, lightweight, and can withstand a variety of temperatures.  This solution is cylindrical in shape, but the top half of the structure is slightly larger than the bottom. The lid has two doors. Both doors have a small handle, which can be used to open each entry to poor water into the system. The exterior also consists of a handle on each side for handling purposes and a spout where clean water exits.

            The exterior of the structure is designed so that the top half is wider in diameter than the bottom half. This solution is designed this way so the base sits on the upper ledge of the bottom half.  The base has a series of small holes where clean water exits the filter. The base also separates the series of filters from the clean water.

            Pros include that the polycarbonate material results in the structure being lightweight, durable, and impact resistant. Due to the diameter of the top half being larger than that of the bottom, the base requires no other support structure than the ledge of the bottom half. Cons include that as a result of the two doors of the lid, the system will be more complicated when taking out the filters to clean and replace them. Also, according to how heavy the materials of the filter are, this may not be the best structure supporting the base of the filters.

Solution 3:

 

            Solution 3 is composed completely of galvanized steel. This is because it is high in strength, impact resistant, durable, and can withstand a wide range of temperatures. This solution is also cylindrical in shape. The lid consists of the center of a sectioned off portion of the top of the structure. The exterior also consists of handles for handling purposes and the spout.

            The interior consists of four bases. Each is standard containing multiple small holes where water enters. Each base is a level and supports a different filter material. This was created so that each material could filter water separately. Each base is slotted into the structure of the container.

            Pros include that the system is created of a strong, lasting material. In addition, each filter material is separated. Cons include that galvanized metals corrode after periods of time. As a result of metals being dense, this solution would be heavier compared to those composed of polycarbonate. This would make handling more complicated due to the weight. Galvanized metals are also more costly compared to polycarbonate. Also, due to the fact that each base (and filter) is slotted into the walls of the container when constructed, to clean or replace filter materials would be impossible.

 

Solution 4:

            Solution 4 is also composed completely of galvanized steel for the same reasons: the material is strong, impact resistant, durable, and withstands a variety of temperatures. The solution is cylindrical in shape and has a screw on lid along with handles and a spout where the clean water exits.

            The interior of the system consists of a lip extruding from the wall of the container encompassing the circumference of the system. The base, with many small holes for water to pass through, supports the series of filters and separates the filters from the clean water.

            Pros include that the system can be easily opened up. As a result the filters are easily extracted, cleaned, and replaced. Due to the galvanized metal, the container is strong and durable. Cons include that the filters may not have enough support if the materials are heavy in weight. Galvanized metals are also more costly compared to polycarbonate. In addition, galvanized metals corrode after periods of time.

 

Tentative Final Solution Sketch and Explanation:

 

            As a result of solutions one and four scoring the highest on the design matrix, the two designs were combined to form a tentative final solution. This solution is composed entirely of polycarbonate so that the system is lightweight, durable, and easily portable. The solution has a screw on lid, handles, and a spout. The interior consists of a rod permanently connected to the bottom of the container. Two lips are attached to the rod so that a base is able to sit on each of the lip. A ledge along the circumference of the interior is also present as a precaution. This ledge assures that the filter materials are supported sturdily. The lid and bases can be removed so that the filters can be extracted, cleaned, and replaced.