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Water management and technology
Published in Jill L. Baker, Technology of the Ancient Near East, 2018
It is said that Archimedes (ca. 287–212 bce) invented the water screw (ca. 241–220 bce) as a way to remedy irrigation problems in Egypt. One of its first non-agrarian uses was as a bilge pump for large grain ships. Scholars speculate that Hieron II King of Syracuse (308–210 bce) loaned Archimedes’ services to the Ptolemies of Egypt to help with the engineering problem. The water screw consisted of a large, solid, cylindrical axle around which a double or triple helix made of wood strips (sometimes bronze) were fixed. The axle and helix were inserted into a barrel casing to facilitate water flow. When the axle and helix were turned, the helix collected water in the spaces between the threads of the screw, thus moving the water up the cylinder. Vitruvius provides a description of a water screw in his work, On Architecture X, 6.1–7 (Morgan 1960:295–297; Oleson 2000b). Originally intended to move water, Archimedes’ screw proved useful for moving grain, rubble, and dirt, and for olive and wine presses. Recent scholarship suggests that Sennacherib (ca. 704–681 bce) may have used a bronze screw to deliver water to the Hanging Gardens of Babylon (Dalley 2013). If this interpretation is accurate, the screw would have been invented and utilized about 350 years before Archimedes developed his screw.
Tailoring
Published in Lory Mitchell Wingate, Systems Engineering for Projects, 2018
Other significant risks involved the kayak. The stability of the kayak associated with a sleeping configuration and during the sail use needed to be addressed. Hicks wanted to sleep lying down in a reclining position for safety and stability, as well as general comfort. His sleeping ritual included processes to “inflate the airbags and put out the sea anchor to steady the kayak, put the tent up, and lie down,” Hicks explained. But having enough space to lie down in the kayak came with a price. The risk of designing the boat with enough room for two people to recline was that there would be a significant amount of open space in the bulkhead that, if capsized, would take in a much higher volume of water. The risk mitigation for this serious survival feature was the installation of a sealed electric bilge pump system, which could empty the kayak in 80 seconds. Hicks felt that he could survive a serious storm lying prone in the kayak in this configuration for six to 10 hours, but that “invariably he and his partner will suffer from stress, exposure and fatigue.” They would be able to continue paddling for short durations but would retire to their sleeping configuration for longer durations and “float like a bottle on the sea” until the storm abated.
The Mechanics of Flexible Liners
Published in Carl Keller, Hydrologic Measurements with Flexible Liners and Other Applications, 2023
The air vent tube of Figure 3.2 can be extended from the top to the bottom of the borehole as a “water removal tube” to pump the water from beneath the liner using a sufficient pump at the surface. A sufficient pump is able to draw the water from the water table to the surface. The liner installation into a borehole of low transmissivity will raise the water level in the water removal tube to improve the flow rate. Typical pumps for pumping from the surface include a simple bilge pump, double diaphragm pumps, or even a peristaltic pump. But peristaltic pumps are too slow to be practical.
Nuisance mucilage produced by Lindavia intermedia (Bacillariophyceae) in New Zealand lakes
Published in Inland Waters, 2022
Phil M. Novis, Tracey J. Bell, Putri Fraser, Cara A. Luiten, Simon F. R. Hinkley, Hugo Borges, Marc Schallenberg
The 35 mm inlet of a 12 V submersible bilge pump (model PE9504, mytools.co.nz) was plumbed directly to an adapted oil funnel with rectangular head (inlet area 260 mm × 170 mm, depth 200 mm; Fig. 1b), over which we secured a support screen made from stainless steel wire mesh (2 mm mesh size; ACYST3M Cyclomesh, Netting Supplies, Amberley, New Zealand). A removable rectangle of nylon mesh (220 µm pore size, bubblebagshop.co.nz) was secured to the support screen using a PVC frame hinged to the funnel on one long edge and closed using bulldog clips. A rim of closed-cell foam glued to the frame on the pump side secured the mesh against movement. We weighted the underside of the pump assembly (0.5 kg) to maintain orientation, and the assembly plus the weight were suspended from the boat with support rope and electrical wire.
Safe and efficient tank cleaning of liquid cargo tankers: a review
Published in Ships and Offshore Structures, 2023
Wanqing Wu, Zhixing Cao, Bin Zhang, Yafei Guo, Min Du, Qinggong Zheng, Zhaoao Bai, Zhongxin Shi
The international general tank cleaning procedures mainly include machine washing, draining, purging, chemical recirculation cleaning, flushing, rinsing, steaming, draining and venting/moping/drying (Tank cleaning guide, tenth edition). (1) Machine wash. Spraying of cleaning medium (usually sea or fresh water) onto the tank surface by means of an automatic cleaning machine without the addition of any cleaning agent to remove as many residual cargoes and sediments from the bulkhead, bilge and top of the tank as possible; (2) Drain. Empty the tank, line and pump thoroughly; (3) Purge. Displacing and dilution of flammable vapours with inert gas; (4) Chemical recirculation cleaning. Preparation of a cleaning chemical solution diluted to the appropriate concentration in water, and circulate the solution through tank washing machines; (5) Flushing. Spraying of water (usually fresh water) through the cleaning machines onto the tank wells, to wash away any residual cargoes and chemical cleaning agent mixture that may adhere to the bulkhead; (6) Rinsing. Spray or recirculation of De-Ionised water to remove chloride from tank surfaces and pipelines and traces of contamination from the tank surface; (7) Steaming. Introducing saturated steam into the tank to accelerate the evaporation of volatile previous cargo residues and further reduce inorganic chlorides; (8) Drain and vent/mop/dry. Draining the bilge, pump and pipeline by a pump or ejector, and carried out ventilation by forced air circulation, either by portable or fixed fans to remove the traces of moisture and odour from the cargo tanks. When the tank is certified as gas free, any free water should be removed by mopping, followed by additional ventilation until the tank is dry.