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Applications of Technology
Published in Roger Timings, Basic Manufacturing, 2006
Beef may be sent from Argentina in special ships so that it can be chilled. Lamb is sent from New Zealand in ships that can keep it frozen. Perishable fruit and vegetables may need to be carefully packed to prevent damage and transported by air to reduce the time taken so that it arrives fresh at your supermarket. Products such as computers and television sets are packed in strong cardboard boxes cradled in preformed polystyrene packing to prevent damage. Many such boxes may be packed into a container to facilitate handling at the docks to prevent damage and theft. Large objects, such as machines, will be transported in strong wooden boxes, called packing cases, when travelling by sea.
Experimental investigation on the performance of modified single basin double slope solar stills
Published in International Journal of Ambient Energy, 2022
S. Joe Patrick Gnanaraj, V. Velmurugan
The length, width and height of each basin were 100, 60 and 40 cm respectively. They were made up of 2 mm thick iron sheet. Each basin was placed inside a wooden box and a gap of 1.5 cm was maintained between the basin and wooden box inner wall. The gap was tightly packed with saw dust. The inner surface of the still basin was painted black to increase the absorption of solar radiation. Each basin was covered by a double slope glass cover. The basin cover was made up of 4 mm thick transparent glass and an angle of 30° was maintained. For collecting the condensed water, drains were fabricated on the two sides of the still. The distilled water was collected in a jar. Each still was connected to the water source through a pipe for periodic top up of water. The water supply was controlled by control valves.
Heat transfer and friction in rectangular solar air heater duct having spherical and inclined rib protrusions as roughness on absorber plate
Published in Experimental Heat Transfer, 2019
A setup has been fabricated to experimentally investigate the friction characteristics and heat transfer behavior of a rectangular duct having one broad heated wall, roughened with spherical and inclined rib protrusions. A schematic diagram of the experimental setup and cross-section of the duct are shown in Figure 2. The rectangular duct fabricated from wood planks has a cross-section of 300 mm × 25 mm for air flow. The rectangular duct consists of three sections, i.e., test section, entry section, and exit section. The length of the test section, entry section, and exit section is 1000 mm, 525 mm (), and 875 mm (), respectively, selected according to ASHRAE standard 93–97 [32]. Top side of the duct, which corresponds to the absorber plate in SAH, is made of galvanized iron on which the roughness geometry is provided. A hollow wooden box () made of 12 mm thick plywood, filled with glass wool, covers the absorber plate, to reduce heat loss from the top. An electric heater (1525 mm long and 310 mm wide) consists of heating element (Ni-chrome wires) which is fabricated over two layers of 4 mm thick asbestos sheets. The electric heating circuit is fabricated by combination of parallel and series loops of Ni-chrome wires. In order to supply uniform heat flux to absorber plate, three series loops of heating elements are connected in parallel.
Experimental investigation of heat transfer augmentation due to obstacles mounted in solar air heater duct
Published in Experimental Heat Transfer, 2022
Himanshu Singh, Tabish Alam, Md Irfanul Haque Siddiqui, Masood Ashraf Ali, Dheeraj Sagar
An experimental setup has been devised and built. Rectangular duct is made of wood and having the following dimensions 2400 mm × 300 mm × 25 mm. The length of the duct is divided in three segments, namely, inlet plenum, test section and outlet plenum with the corresponding length of 525 mm, 1000 mm, and 875 mm. The length of entry plenum and outlet plenum are chosen more than the recommend length of 5×√(W × H) and 2.5×√(W × H), respectively, which limits the end effect of duct in the flow over test section [50]. GI sheet of thickness 0.5 mm with the following dimension 1525 mm and 300 mm has been placed in the duct as absorber sheet. One side of the absorber sheet has been painted black to absorber the maximum possible heat. The schematic cross sectional and plan view of experimental setup have been shown in Figure 1. In order to simulate the heat flux of 1000 W/m2 which need to supply to absorber plate, electrical heating has been exploited. Nichrome wires has been exploited for electrical heating. Three loops of nichrome wire connected in parallel and have been fixed on wooden box of size 2400 mm, 360 mm, and 100 mm. Wooden box has been constructed using 6 mm plywood wherein glass wool has been filled to avoid the heat loss to environment. Nichrome wire are placed with 10 mm gap on the asbestos sheet with strips of mica to maintain the uniform distance between wires. The whole assembly of the electrical heater is fixed on the wooden box. Controlled electrical power supply is given to electrical heater through single phase supply. Variac control the voltage and current to simulate heat flux of 1000 W/m2 over absorber plate.