The Trend in Water Works Pumping Machinery
Operating Economy Looked Upon as a Determining Factor—Things to be Considered in Planning Installations — The Various Classes of Pumps
WHILE modestly disclaiming any power of prophecy, there is no doubt that the author of this article is one of those best qualified to foretell the future of water works pumping machinery, and his article will be read with great interest by all interested in the subject.
What the future will bring forth, no one knows; our only means of judging must be based on past experiences and present indications; if we make our deductions properly from the information at hand and cast our horoscopes of the future correctly, we may be classed as prophets, but inasmuch as we are not prophets nor the sons of a prophet, it is with fear and trembling that we venture into the unexplored fields of the future.
Generally speaking, the word “machinery” in its broader sense may be held to apply to any mechanism of mind or matter; so future developments must be governed by future conditions of mind and matter, the latter being controlled directly by nature’s laws, the former no less absolutely, but perhaps less infallibly because of lack of full knowledge or the lack of power to apply existing knowledge along lines of greatest efficiency.
The Past, the Present and the Future
The past, as we know it, has been a period of slow development, reaching always toward higher levels, seemingly at times receding like the waves of an incoming tide, but inevitably coming back stronger and approaching nearer the higher levels of attainment. The present is a period of being, a line of demarkation over which constantly flows the future into the past; as we utilize and perhaps direct this flow in such measure may our anticipations of what the future will bring forth be realized.
Must Promote Life, Health and Happiness
Pumps and pumping machinery in the water works field have been and will be a fundamental and economic necessity in world development and progress. No community may continue to exist without a water supply, and it should be a proper supply to best promote life, health and happiness, in fact no other kind of water supply may be considered fundamentally economic.
In days of natural water supply, that is, when man and beast were dependent on what they found, their numbers and distribution were limited to those areas in which suitable water for drinking and other purposes was available, but necessity is the mother of invention, and the distribution of water was increased by artificial means. It was conveyed in receptacles on the backs of men and beasts; it was dug and hoisted out of the ground, and was conveyed by gravity in ditches and pipes. This led to a further increase and spread in the world’s population which created the necessity for elevating water from lower to higher levels. This necessity was met and overcome by mechanical contrivances actuated at first by manual or animal labor, afterward by elemental labor as ways and means were devised for harnessing and utilizing the elements for this purpose.
Economy, After Ability, Most Important Factor
At first no particular attention was given to economy. The result to be attained, that is the ability to elevate water received first consideration, then gradually the question of economy in conjunction with ability forced its way to the front until now economy after ability is a most important factor and in the future bids fair, by virtue of necessity, to be the most important factor.
The mechanical developments for the purpose of elevating water from a lower to a higher level generally given the name of pumps or pumping machinery have required, and doubtless always will require, the expenditure of more or less power to produce useful work. This power may be divided into two general classes: Natural, in which may be included wind and water powers, and artificial, in which may be included powers produced by the ingenuity of man, such as steam, electric, and internal combustion, so-called.
Comparative Amounts of Power First Consideration
As already indicated recent past and present experiences point to the inevitable conclusion that future developments of pumps and pumping machinery in the water works field must be subject to economic considerations almost “in toto.” There may be exceptions, but these will be so rare that they will not influence the ultimate result. Among the future economic considerations in addition to that of first cost will be that of conservation, not only as applied to natural, but also to artificial powers, so that the greatest good may apply to the greatest number, and it is safe to say at this time that in planning future pumping developments in this field we must make the comparative amounts of power involved by various types a matter of first consideration, for the wasteful use of power tends to increase its cost to the community at large.
Conservation of Power
In making economic comparisons consideration must be given to this element, and some definite acceptable value for it determined. This will apply equally to all apparatus that will consume power. For future pumping installations for water supply the following for purposes of comparison must receive consideration:
Cost of installation.
Interest on cost.
Amount of power required.
Cost’ of power.
Conservation value of power required.
It will be comparatively easy to determine a value for all items except that of the conservation value of the saving of power, which, while at the present time is apparently almost negligible, will undoubtedly in the future receive more and more attention and more weight will be given it.
Three General Classes of Pumping Machinery
Water works pumping machinery may be divided into three general classes:
- —Centrifugal and rotary.
- —All not included in 1 and 2.
Class 1 is well established, is economical as a class in the use of power, though as a rule its units are of comparatively high first cost. It, as a class will, as far as we can see into the future, always be of great utility because of its known reliability, efficiency and economy of operation. It has in recent years progressed in development, but perhaps not as rapidly as some of the types of t lass 2, but there are indications that it is entering upon a new era of development that will materially enhance its comparative value.
Class 2—Of the type embraced in this class, the centrifugal as to both pump and power features, has made very rapid progress in development in the past ten years, and has earned a recognized place for itself among water works pumping installations; if it continues to develop in the future as rapidly as it has in the recent past, its field of operation will constantly broaden and become more comprehensive; but periods of comparative advancement frequently move in waves, rapidly at times, then follow periods of stagnation and sometimes periods of apparent recession. Upon its percentage of ultimate development already attained will its future largely depend, but notwithstanding any future uncertainties its present development is a guarantee that it will occupy an important place in the pumping world for the conditions to which it is suited. There has not been sufficient progress in recent rotary pump development to indicate that it will be entitled to serious consideration except in very special cases.
Class 3, among others, includes gas explosion, and pulsating pumps, also air lift appliances. Gas explosion pumps are yet in their rudimentary state of development and unless rapid and great improvements are made, this type does not hold out much promise for general use. There will be a limited field for the other two.
Cost of Power Future Determining Factor
I he cost of power will be the principal determining factor in the future of pumps in the water works field and the type that can utilize power to best advantage will be the dominating type. As power simply, air, that is, wind is the cheapest, but it is so intermittent and unreliable that it cannot be considered. Water power when continuous and its development costs are not too great is so readily transformed into electrical power capable of being transported economically for great distances, that in combination with reciprocating and centrifugal pumps for small water works installations, it will probably come into general use, but in larger installations its application in most cases will be prohibitive on account of cost.
Of the so-called artificial powers, steam is the one used in the great majority of water works pumping plants both for reciprocating and for centrifugal pump drive; but power produced by direct or internal combustion engines is quite rapidly coming to the front, its development will depend largely upon the comparative prices of coal and oil. There is, however, no present indication of any material change in these relative prices. This being the case, the development of the internal combustion engine will surely wield a great influence.
As to Future Development
If we interpret the past correctly in judging the future, there will be a gradual improvement in efficiencies due to the perfection of designs for utilizing to better advantage the various powers that will be available; that for smaller installations there will be a tendency toward electric drive both for reciprocating and for centrifugal units, that for larger installations except where water power is directly available, steam driven pumps both reciprocating and steam turbine driven centrifugal will, for some time to come, continue to be the dominating types, with improved economies and efficiencies due to higher steam pressures and superheat.
There will be improvements in each of these classes, but their relative positions will not change materially. In addition to the foregoing will be the internal combustion prime mover with direct applications to reciprocating units and shaft and gear applications to reciprocating and centrifugal units.
Inasmuch as the internal combustion engine is only in its infancy, but a healthy infancy nevertheless, one can hardly predict at this time what its possibilities will be, but apparently it is the coming artificial prime mover and will be, before many years, with its various pump Combinations, one of, if not the dominating feature of pumps and pumping machinery in water works field.