Vízügyi Közlemények, 1936 (18. évfolyam)

Kivonatok, mellékletek - Kivonat a 2. számhoz

VIII. If water meters are employed, the maximum,,consumption in this country may be assumed as 150 litres per capita day, and the average consumption as 100 litres. As spring waters are rarely at our disposal, and as our population is averse to using surface waters, we are mostly dependent on ground water procured by deep boring, and on river water obtained from wells disposed along the river bank, passed through a natural filter. Water may be distributed by means of a system working under hydrostatic pressure, or pneumatic pressure procured by compressing air in closed chambers (the hydrophor system). As to the dimensions of pipes, the hydrophor system is equivalent to an arrangement where the distributing reservoir is placed in front of the consuming area (fig. 7) ; in this case the main pipe is of greater dimension than in the case of a reservoir beyond or in the centre of the consuming area. Figures 8, 9 and 10 show the pressure in the pipe system with a hydrophor, a reservoir beyond the consuming area, and a water tower erected in the centre of the city respectively. The operation of the hydrophor system is always automatic, and only electric current can be employed as a source of energy. This is economic when the current is supplied by a large central plant, for with a small local plant frequent and impulsive changes in the consumption of the electric current are disadvantageous. As no water is stored, good reserve machines have to be provided. As to the construction costs, when a suitable hill is found near the town to be supplied, the distributing reservoir offers the cheapest and safest solution. In the absence of such a hill, the hydrophor system may also enter into combination, but only when the electric current is delivered by a large power plant. The question of the material of pipe has also come into prominence. At present cast iron piping is still mostly employed, but the use of asbestos-cement pipes is increasing. Besides its other advantages, this piping is about 25 per cent cheaper than the cast iron sort. Asphalt pipes have recently come into the market ; these are not attacked by acids, but sufficient experience of their use is yet wanting. The water rate is an important factor in the problem of supply, and has to be taken into account in the design. Under our conditions it would be desirable that the water rate should not be higher than 25 fillér per cubic metre, because the populations, mostly agricultural, of our towns could hardly support a heavier impost. VI. SOME NEW WATER POWER PLANTS IN FRANCE. By Dr. Ing. W. LÁSZLÓFFY. (Pages 216—234.) Electrification has made great advance in the post-war years, and in this field, especially in the construction of water power plants, some prominent establishments have been completed in France. The author describes a few of the chief projects, which lie visited during his study trip in 1935 with the kind aid of local authorities and companies. The projects described, and their main features, are as follows :