FISH TRANSPORT DESIGN - Assignment Example

?Fish Transport Design Transporting fish from location to location is often hazardous to fish health. The promotion of stress to fish during transportation and handling is considered harmful to fish life. In extreme cases, the fish may die. Extreme circumstances for fish death are far different from human standards. Even though humans may exist in lowered oxygen levels (14% minimum), even slight variations in aerated oxygen levels can spell death for fish. The safe transportation of fish is a large problem because the death of fish can spell financial trouble for fish owners. This is exacerbated by the fact that certain tropical fish such as the Koi Carp are particularly expensive. This investigation is aimed at delineating criteria to transport fish followed by three concept level models. These models will be evaluated against the delineated criteria and the most suitable model will be chosen to transport fish over long distances. The business viability of the chosen model will be evaluated in terms of investment and operational costs to help fish owners and transporters decide if they wish to install such a system. Constraints Numbers of Fish and Time for Transport The current problem clearly states that fish will have to be transported in numbers between 5 and 200 and that the fish can stay on the road for up to 2 days. The most expensive fish in the lot is the Koi Carp. The Koi Carp is potentially a very sensitive fish and needs to be cared for excessively. (Koi Carps, 2009) For the purpose of this investigation, the baseline of water quality will be taken as that for the Koi Carp. If the water quality for the Koi Carp falls below certain constrained levels, then a major loss or failure will be assumed. Constraint 1 ? maximum transportation time will be 2 days (48 hours) As mentioned before, the baseline will be taken for Koi Carp. Thus aeration constraints will be developed along the lines for the Koi Carp. The density of Koi Carps should be kept at 80 cm length of fish for every 1 m3 volume. (Koi Carps, 2009) The average size of the Koi Carp is between 24 and 36 inches. If these values are averaged, the size of an average Koi Carp comes out to be 30 inches (76.2 cm). (Davis, 2011) Constraint 2 ? fish density based on average size 76.2 cm Water Quality The largest problem in maintaining healthy fish is the dissolved oxygen level. Any variations in the oxygen level can spell disaster for fish especially if the oxygen levels are not replenished after half an hour to acceptable levels. (FAO, 2011) Any and all factors that affect dissolved oxygen levels in water must be considered and dealt with accordingly. Generally the aeration system is constrained by: efficiency of the aeration system; transport duration; temperature of water; fish size; fish species. It is essential that the water used to house fish is kept clear. Any turbidity should be avoided and filters should be installed in the system to remove any particulate matter. Constraint 3 ? turbidity clarity Moreover, the pH level must be checked regularly to ensure that it keeps around 7. The acceptable pH levels for housing fish are 6 to 8.5. Constraint 4 ? pH level average at 7 Water temperature has a direct bearing on the amount of oxygen dissolved in water. Oxygen solubility in water decreases exponentially as the temperature of water increases. Therefore, if the water temperature rises significantly as the fish are being transported, the oxygen levels in water will suffer significantly. (Engineering Toolbox, 2011a) The variations of oxygen levels with water temperature are graphed in Appendix A. Constraint 5 ? water temperature should not vary significantly Moreover, the oxygen content of the water needs to be checked regularly to ensure that it does not fall below the designated threshold of 5 mg / litre. The variation in oxygen levels is between 8 and 9 mg / litre. Constraint 6 ? oxygen levels in water averaged at 5 mg / litre Moreover, the water quality should be maintained within the constraints listed above and no value should be allowed to vary rapidly. Constraint 7 ? rapid variations in critical parameters should be avoided Fish are transported on land by using tankers attached to Lorries. Generally these tanks are elliptical in shape and typical size for tanks is between 1,000 and 2,000 litres while the maximum capacity is 4,500 litres. Using elliptical tanks ensures that water circulation is optimal and that the centre of gravity lies at or near the maximum strength region on the truck chassis. (FAO, 2011) Moreover, auxiliary devices are also attached to such tanks including water pumps to ensure circulation, on board oxygen supply tanks, oxygen level monitors, temperature monitors etc. (Ponds UK, 2010) Constraint 8 ? use of auxiliary devices As the fish may be kept for a long period of time during transportation so there must be some mechanism to remove the excrement they produce. The excrement of fish increases the level of nitrates and nitrites in water which eventually leads to the formation ammonia. (Koi Carps, 2009) Ammonia is highly soluble in water given that one volume of water can dissolve 1300 volumes of ammonia. (Engineering Toolbox, 2011b) Please see Appendix B for variations in ammonia solubility in water against temperature. The best way to avoid ammonia formation is to filter out nitrates and nitrites as soon as possible. This way they are not allowed to decompose into ammonia. This can be achieved by utilising a filtration system that operates in tandem with the water circulation system. (Koi Carps, 2009) Constraint 9 ? inclusion of a filtering system More than one kind of fish can be transported simultaneously as per consumer demands. Certain fish may devour other species of fish and this would represent a loss. In order to deal with this issue, baffles must be provided that separate certain species of fish from each other to ensure a safe journey. Constraint 10 ? provision of separation system The constraints listed above will be used as design criteria. Product Design Specifications The following Product Design Specification is intended for a fish transport system. 1. Physical and Operational Characteristics a. Performance Requirements: The system should be able to transport between 5 and 200 fish such that they can be sustained for around 48 hours on the road. b. Life in Service: The device should be able to serve transport cycles for a reasonable amount of time. c. Material: The material used to construct the tanks should be food grade quality at least so that fish are not poisoned. d. Safety: The tank should be constructed and mounted onto the lorry in such a way that it does not dislodge during transportation. Moreover, the tank should be able to withstand operating pressure and should conform to relevant standards including welding standards for manufacturing and testing. The tank should not fail under sustained low temperatures due to brittle or other failures. e. Corrosion: All regions in contact with water should either be corrosion proof or should corrode at predictable levels that do not poison the transported fish. f. Operating Environment: The tank should be able to maintain operating temperatures consistently for long periods of time. The temperatures should be kept around room temperature and major variations should not be allowed. g. Capacity: The tank’s capacity should at least be 4,500 litres to transport fish safely. h. Baffles: The transported fish should be kept separate as required for which baffles should be implemented in the tank. 2. Health of Fish a. Monitoring: Fish health must be constantly ensured through active monitoring of the water they are contained in. Critical parameters should be identified and constantly monitored. b. Cabin based Apparatus: The cabin of the lorry should house apparatus that would facilitate the monitoring activities as well as the corrective actions such as dosing. c. Auxiliary Devices: The lorry and the tank should be fitted with auxiliary devices such as pumps, oxygen tanks, spare filters etc. to facilitate the operation. d. Insulation: The tank should be insulated using non toxic materials and the use of asbestos for insulation is prohibited. 3. Loading and Unloading a. Loading: The loading devices should be built to facilitate loading activities for both water and fish. b. Unloading: Unloading channels should be installed on either side of the tank with the installation near the base of the tank to ensure proper drainage. c. Drainage: The drainage scheme should be optimised to ensure that no water is left over in the tank which could rot and cause harm to fish during transportation. d. Emergency Drainage: The tank should be fitted with emergency drainage ports that can be opened up in case of an accident or other such emergency. 4. Production Characteristics a. Target Production Levels: The intended system is not designed for mass manufacturing and the design should reflect this through appropriate customisations. b. Target Production Cost: The production cost should not exceed $ 10,000. 5. Maintenance a. Design: The system should be designed for optimal maintenance ease including ergonomic considerations for technicians working on the system for maintenance. b. Spares: The system should use components and assemblies whose spares are readily and easily available to ensure ready and easy maintenance. Concept Designs Design One This design is centred on the most primitive approach to moving fish by land. It includes the use of polyethylene bags to house the fish and transport them. Fish are moved by placing them in bags with water that has been enriched with oxygen by allowing oxygen tanks to leak into the water at controlled rates. The bags are often contained in larger boxes of fibre glass which are subsequently put on trucks for transportation. Temperatures are kept constant by using insulated fibre glass containers. If need arises, ice is added to the water to ensure that temperatures keep low enough during transportation. In other circumstances, small refrigeration units may also be mounted on truck beds to cool the polyethylene bags. However, temperature control remains an issue. Water quality is checked at regular or specified intervals using small instruments. Water is replaced at times if water quality drops too low. Oxygen tanks are also kept handy to replenish oxygen levels as required. Design Two The second system to transport fish consists of stationary containers made out of either strong plastics or fibre glass. The containers are insulated through thick construction walls. Containers are often no larger than 1,000 litres. The containers can easily be moved from location to location and are easy to fill and drain. The containers are filled from the top and the fish are deposited from there too. In contrast, the containers are drained from the lowest points through attached pipes. The water in these containers can be monitored either manually or automatically if such provisions are allowed. Pumps based on truck beds can be configured to circulate water in one or more containers as these containers are often used in combination. This helps to transport fish easily while keeping them separated at the same time. A sample arrangement is shown in Appendix C. Design Three The third deign comprises of a singular tank mounted on a lorry bed that is separated by baffles. The entire system is fixed permanently to the back of the lorry. The greatest capacity for transportation is offered by such systems. Auxiliary devices such as pumps, oxygen cylinders, refrigeration systems, monitors etc. are all attached to the back of the lorry for ease of access and management. The system is easy to monitor, manage and maintain at the same time. The tank installed is around 4,500 litres in total capacity. The installation of a single tank ensures that all services such as refrigeration and other auxiliary devices are common to the entire system. These systems are often far more expensive than other types of systems. An example is provided in Appendix D of a similar system mounted on a lorry. Comparison of Design Concepts A comparison of the design concepts listed above are provided as per the design constraints listed before using a matrix format. Each constraint is provided with a weight between 1 and 5 with 1 being lowest and 5 being highest. Similarly, the design’s relative compliance is listed on a scale between 1 and 10 with 1 being lowest and 10 being highest. The weight will be multiplied with each design’s individual score to determine the optimal system that would possess the greatest score. Constraint Weight Design One Design Two Design Three maximum transportation time will be 2 days 4 5 7 10 fish density based on average size 76.2 cm 4 8 8 10 turbidity clarity 3 4 6 8 pH level average at 7 5 5 7 10 water temperature should not vary significantly 5 5 7 10 oxygen levels in water averaged at 5 mg / litre 5 8 8 10 rapid variations in critical parameters 5 5 7 10 use of auxiliary devices 4 1 5 10 inclusion of a filtering system 3 1 5 10 provision of separation system 2 10 10 10 Total 206 278 394 Detailed Implementation of Optimal Idea Based on the evaluative matrix above it is apparent that Design Three is the optimal idea. To implement this idea, the system should posses a complete tank with a total capacity of 4,500 litres with baffles inserted to house different species of fish. The tank should be supported on the rear chassis of the lorry or the designated. The system should also house auxiliary devices which include: recirculation pumps (one active, one standby); duplex filter system with 1 to 2 micron filters; refrigeration unit (positive displacement based compressor system); aeration unit with oxygen tank and associated piping including: pressure safety valves; bleeding arrangements. monitoring systems oxygen sensors (distributed in each separate baffle region); pH level sensors (distributed in each separate baffle region); ammonia level monitors (distributed in each separate baffle region); pressure sensors to avoid over pressurising each baffled region (distributed in each separate baffle region); loading docks on top of tank to fill up water and insert fish; unloading pipes at tank bottom with separation for baffled regions (pipe size at least 8 inches); insulation on the sides of the tanks externally; cabin based monitoring apparatus; cabin based dosing systems for oxygen, pH control chemicals etc.; pressure relief devices (pressure safety valves); supporting tubes, piping, valves and wiring; supporting tools for maintenance while on the road; ladders on the back of the tank welded in place to facilitate mounting and dismounting the tanker. Business Plan The financial structure of this system would consist primarily of the upfront capital cost followed by the operating costs as well as the maintenance costs over time. The payback period for the entire system can be taken at a fixed value with straight line depreciation. The correlation of the finances is delineated below. payback period = capital cost / time required to generate capital cost in profits profit = total costs of shipping to consumer – operational costs – maintenance costs operational costs = fuel costs + oxygen costs + chemical dosing agents cost + refrigeration costs + driver’s pay + water costs + filter costs + clean up costs after each trip maintenance costs = cost of spares + cost of engine oil and air filters + miscellaneous lorry maintenance costs + preventive maintenance costs for refrigeration unit + preventive maintenance costs for aeration unit + costs of seals installed requiring regular changes + frequency defined water tank check up costs break even period = (total capital cost + operational costs + maintenance costs) / profit based on these calculations, it can be reliably said that the prospective fish transporter can readily decide if they want this system installed. Bibliography Davis, B.K., 2011. Koi - Living Works of Art. [Online] Available at: HYPERLINK "http://www.jadedragon.com/koi/koiart.html" http://www.jadedragon.com/koi/koiart.html [Accessed 13 August 2011]. Engineering Toolbox, 2011a. Oxygen Solubility in Water. [Online] Available at: HYPERLINK "http://docs.engineeringtoolbox.com/documents/841/oxygen_solubility_fresh_sea_water.pdf" http://docs.engineeringtoolbox.com/documents/841/oxygen_solubility_fresh_sea_water.pdf [Accessed 13 August 2011]. Engineering Toolbox, 2011b. Solubility of Gases in Water. [Online] Available at: HYPERLINK "http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html" http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html [Accessed 13 August 2011]. FAO, 2011. Open Systems of Fish Transport. [Online] Available at: HYPERLINK "http://www.fao.org/docrep/009/af000e/AF000E05.htm" http://www.fao.org/docrep/009/af000e/AF000E05.htm [Accessed 13 August 2011]. Koi Carps, 2009. Conditions of KOI carp breeding. [Online] Available at: HYPERLINK "http://www.koi-carps.com/koi-carp-breeding-conditions.html" http://www.koi-carps.com/koi-carp-breeding-conditions.html [Accessed 13 August 2011]. Ponds UK, 2010. Fish Transport. [Online] Available at: HYPERLINK "http://www.pondsuk.com/fresh-water-fish/fish-transport/" http://www.pondsuk.com/fresh-water-fish/fish-transport/ [Accessed 13 August 2011]. Appendix A Appendix B Solubility of Ammonia in Water against temperature of Water Appendix C Appendix D Truck bed installation including refrigeration system and auxiliary pumps Full tank and auxiliary device installation along with aeration system Read More