Chapter V: Part 5

================+===============+=========+=================+================
| | | | Diameter of
| | | |Plunger required
| | | | in any single
Diameter of | Diameter of |Length of|Gallons delivered|cylinder pump to
Steam Cylinders.|Water Plungers.| Stroke. | per minute at |do the same work
| | | ordinary speed. | at same speed.
----------------+---------------+---------+-----------------+----------------
6 | 7-1/2 | 6 | 285 | 10-1/4
6 | 8-1/2 | 6 | 375 | 12
----------------+---------------+---------+-----------------+----------------

================+===============+=========+=================================
| | |Sizes of Pipes for Short Lengths
| | | To be increased as length
| | | increases.
Diameter of | Diameter of |Length of|------+---------+-------+--------
Steam Cylinders.|Water Plungers.| Stroke. |Steam | Exhaust |Suction|Delivery
| | |Pipe. | Pipe. | Pipe. | Pipe.
----------------+---------------+---------+------+---------+-------+--------
6 | 7-1/2 | 6 | 1 in.|1-1/2 in.| 5 in. | 4 in.
6 | 8-1/2 | 6 | 1 „ |1-1/2 „ | 6 „ | 5 „
----------------+---------------+---------+------+---------+-------+--------

The purposes for which pumps are used on shipboard, aside from the air and circulating pumps for condensers, are:

(1.) Feeding the boiler.

(2.) Emptying the tanks and pumping out bilge.

(3.) Supplying water for washing down decks, extinguishing fires, filling evaporators and sanitary service.

A special pump for each separate purpose is not always supplied, but one pump may have the necessary pipe connections to serve alternately various duties.

Feeding the boilers is so important an operation that a supplemental special pump is always required. To make absolutely sure of an ample supply of feed water one of the other pumps is made strong enough to serve the same purpose, or sometimes an injector is fitted as an auxiliary feeding mechanism.

A bilge pump has special fittings, for the reason that it handles very dirty water, undesirable to be transmitted through any other pipe system. In small ships, however, one pump, the so-called “donkey,” often serves for nearly all other purposes, including auxiliary boiler feeding.

A special form of pump in use on Western river steamers is the so-called “doctor,” an independent pump with a walking beam, by which one steam cylinder drives a system of pumps for feed, fire and bilge pumping purposes (Fig. 450).

The feed pump should be of simple construction, great strength and ample capacity, to secure great regularity and reliability of service under the severe conditions of high pressure.

The main parts of auxiliary feed pumps are often duplicated. This is a desirable point, as one set of spare parts in piston, rings, valves, etc., is suitable for both pumps.

The main feed pump is, even in the independent type, often placed in the engine room, while the auxiliary pump, or the injector, is in the fire room. The feed pumps draw usually from the hot well, feed heater and feed tanks and discharge through main feed pipe into the boiler.

_This “doctor” pump_ is a substantial piece of mechanism. The bases of columns and pump chamber flanges are accurately planed, the cylinder has spring piston packing and the plain slide valve is made of gun metal.

The hot water pumps, 3-1/2″ diam. × 10″ stroke, have chambers bored and are fitted with a copper and tin composition for valves and scats; the latter are driven into their places and riveted over underneath.

NOTE.—Each valve is reached by removing the bonnet covering it. The
joints under caps are made the insertion of sheet lead. The heaters
above the frame, as shown, are 22″ × 5′ 0″ long, of hard rolled
copper, with a copper worm 18′ 0″ long by 2-1/2″ diameter in each.
There is also a baffle plate above the water line in each heater to
prevent the exhaust from throwing the water out at the top.

HYDRAULIC GAUGE TEST PUMP.

These gauges are apt to get out of order for various reasons namely, there is no theoretical method of determining the motion of the pointer due to a given pressure; this is done by tests in which known pressures are employed, and accordingly the divisions on the graduated scale are usually unequal, hence these instruments are tested by attaching them either to a mercury column, or to a dead weight safety valve having for its seat an exact square inch surrounded by a knife edge, or a piston of standard area loaded with weights. This sharp edge is covered by a fibre washer of leather for moderate pressures, say 150 lbs. per square inch, or vulcanized fibre or its equivalent for higher pressures.

Fig. 451 represents a pump that can be used for pressures up to 10,000 lbs. per square inch. The Hand-Lever Pump shown at the right in cut is used for filling the Pressure Pump cylinder and connections with oil or glycerine, and may also serve for testing gauges of low pressures up to 15 or 20 lbs. The suction pipe _a_ is connected with the reservoir containing the oil or glycerine, which after being used is discharged by valve _d_ and returned into the reservoir by pipe _c_.

In filling the pump the cylinder spindle has to be screwed all the way out, and the valves _b_ and _d_ closed before it is put under pressure.

“SUGAR-HOUSE” PUMPS.

The handling of semi-liquids, commercially known as _thick stuff_, has always been considered more or less of a serious problem, and many designs of mechanism in the form of pumps have been invented for that purpose.

_For pumping tar the improved forms of rotary pumps_ have recently come largely into use. These will be described later under their proper heads. Fig. 212, page 232, Part one, represents a very satisfactory design of plunger pump for handling the heavy stuff alluded to.

_The Deane single sugar-house pump_ is shown in Fig. 452. These are largely used for pumping molasses, syrup, cane-juice, melter-pan products, etc., and are fitted with linings, valves, etc., to best suit the condition of the fluid to be pumped.

The valves are very large and the motion of the pumps is somewhat slower than for water. By removing one set of bolts all the valves are uncovered.

These products of the sugar-house when of a high temperature can be pumped nearly as fast as water; the following list gives the approved proportions of these pumps.

TABLE.

===========================+=======================
SIZE. | CAPACITY.
--------+--------+---------+-------+-------+-------
Diameter|Diameter|Length of|Gallons|Strokes|Gallons
of Steam|of Water| Stroke | per | per | per
Cylinder|Cylinder| |Stroke |Minute |Minute
--------+--------+---------+-------+-------+-------
4-1/2 | 4-1/2 | 5 | .34 | 125 | 43
5-1/2 | 4-1/2 | 7 | .48 | 125 | 60
6 | 5-1/2 | 7 | .72 | 125 | 90
7-1/2 | 7 | 10 | 1.66 | 100 | 166
7-1/2 | 8 | 10 | 2.17 | 100 | 217
6 | 6 | 12 | 1.47 | 100 | 147
8 | 6 | 12 | 1.47 | 100 | 147
8 | 7 | 12 | 2.00 | 100 | 200
8 | 8 | 12 | 2.61 | 100 | 261
--------+--------+---------+-------+-------+-------

===========================+===============================
SIZE. | PIPE SIZES.
--------+--------+---------+-----+-------+-------+---------
Diameter|Diameter|Length of|Steam|Exhaust|Suction|Discharge
of Steam|of Water| Stroke | | | |
Cylinder|Cylinder| | | | |
--------+--------+---------+-----+-------+-------+---------
4-1/2 | 4-1/2 | 5 | 1/2 | 3/4 | 2 | 1-1/2
5-1/2 | 4-1/2 | 7 | 3/4 | 1 | 3 | 2-1/2
6 | 5-1/2 | 7 | 3/4 | 1 | 3 | 2-1/2
7-1/2 | 7 | 10 | 1 | 1-1/2 | 5 | 4
7-1/2 | 8 | 10 | 1 | 1-1/2 | 5 | 5
6 | 6 | 12 | 3/4 | 1 | 4 | 4
8 | 6 | 12 | 1 | 1-1/2 | 4 | 4
8 | 7 | 12 | 1 | 1-1/2 | 5 | 4
8 | 8 | 12 | 1 | 1-1/2 | 5 | 5
--------+--------+---------+-----+-------+-------+---------

_The Single Magma Pump._ The term _magma_ includes any crude mixture, especially of organic matters in the form of a thin paste, it also means “a confection,” hence, the name given to the pump illustrated in Figs. 453 and 454 is very appropriately applied to a sugar-house apparatus. It is designed for pumping various thick heavy mixtures and semi-liquids and for moving massecuite, second and third sugar.

The construction in Fig. 453 is such as to insure strength and certainty of operation; there are no intricate small parts, and the interior is readily accessible. These pumps are made with brass-lined cylinders, or cylinders and fittings entirely of composition when needed to overcome the difficulties appertaining to pumping acidulous and corrosive liquid substances.

_The single fly-wheel magma pump_ as shown in Fig. 454 represents the highest type of machine for this class of work. The steam end is of the plain slide valve pattern. _It is fitted with a heavy fly-wheel_, perfectly balanced. The admission of steam is regulated by a throttling governor of approved design. The fly-wheel and governor insure a uniform speed of the pump under variations of load—hence the fly-wheel pump does not require adjustment of throttle for every variation in water pressure, as is necessary with direct acting pumps.

The following table applies to the two styles of the magma pumps—with and without the fly-wheel, as the pump ends are the same in both. Attention is called to the number of strokes per minute (thirty) shown in the table as compared with the number of strokes (100 and 125) called for in the previous table. This is caused by the different viscosity of the stuff to be handled by these machines.

TABLE.

==================================+=============================
|
SIZE. | CAPACITY.
------------+----------+----------+---------+---------+---------
| | | | |
Diameter of | Diameter | Length | Gallons | Strokes | Gallons
of Steam | of Pump | of | per | per | per
Cyl. | Cyl. | Stroke | Stroke | Minute | Minute
------------+----------+----------+---------+---------+---------
5[B] | 3 | 7 | .21 | 30 | 6
5 | 4 | 12 | .65 | 30 | 20
6 | 5 | 12 | 1.02 | 30 | 31
8 | 6 | 12 | 1.47 | 30 | 44
10 | 6 | 12 | 1.47 | 30 | 44
12 | 6 | 12 | 1.47 | 30 | 44
8 | 7 | 12 | 2.00 | 30 | 60
10 | 7 | 12 | 2.00 | 30 | 60
12 | 7 | 12 | 2.00 | 30 | 60
14 | 7 | 12 | 2.00 | 30 | 60
8 | 8 | 12 | 2.61 | 30 | 78
10 | 8 | 12 | 2.61 | 30 | 78
12 | 8 | 12 | 2.61 | 30 | 78
14 | 8 | 12 | 2.61 | 30 | 78
------------+----------+----------+---------+---------+---------

==================================+=======================================
|
SIZE. | PIPE SIZES.
------------+----------+----------+-------+---------+---------+-----------
| | | | | |
Diameter of | Diameter | Length | | | |
of Steam | of Pump | of | Steam | Exhaust | Suction | Discharge
Cyl. | Cyl. | Stroke | | | |
------------+----------+----------+-------+---------+---------+-----------
5 | 3 | 7 | 3/4 | 1 | 3 | 2
5 | 4 | 12 | 3/4 | 1 | 4 | 4
6 | 5 | 12 | 3/4 | 1 | 6 | 5
8 | 6 | 12 | 1 | 1-1/2 | 8 | 6
10 | 6 | 12 | 1-1/2 | 2 | 8 | 6
12 | 6 | 12 | 2 | 2-1/2 | 8 | 6
8 | 7 | 12 | 1 | 1-1/2 | 8 | 6
10 | 7 | 12 | 1-1/2 | 2 | 8 | 6
12 | 7 | 12 | 2 | 2-1/2 | 8 | 6
14 | 7 | 12 | 2 | 2-1/2 | 8 | 6
8 | 8 | 12 | 1 | 1-1/2 | 8 | 6
10 | 8 | 12 | 1-1/2 | 2 | 8 | 6
12 | 8 | 12 | 2 | 2-1/2 | 8 | 6
14 | 8 | 12 | 2 | 2-1/2 | 8 | 6
------------+----------+----------+-------+---------+---------+-----------

==================================+=================
| Approx.
SIZE. | Dimensions
------------+----------+----------+ in Feet
| | | and Inches
Diameter of | Diameter | Length |--------+--------
of Steam | of Pump | of | |
Cyl. | Cyl. | Stroke | Length | Width
------------+----------+----------+--------+--------
5 | 3 | 7 | 4-7 | 1-3
5 | 4 | 12 | 6-11 | 1-5
6 | 5 | 12 | 7-0 | 1-9
8 | 6 | 12 | 7-5 | 2-7
10 | 6 | 12 | 7-7 | 2-7
12 | 6 | 12 | 7-7 | 2-7
8 | 7 | 12 | 7-6 | 2-7
10 | 7 | 12 | 7-7 | 2-7
12 | 7 | 12 | 7-7 | 2-7
14 | 7 | 12 | 7-7 | 2-7
8 | 8 | 12 | 7-6 | 2-8
10 | 8 | 12 | 7-7 | 2-8
12 | 8 | 12 | 7-7 | 2-8
14 | 8 | 12 | 7-7 | 2-8
------------+----------+----------+--------+--------

[B] This size has Tappet valve motion.

CIRCULATING PUMPS.

_The definition of the word circulation_ conveys the best idea of this mechanism—“The act of moving in a circle, or in a course which brings the moving body to the place where its motion began,” hence, a circulating pump is one which causes the water to flow through a series of pipes or conduits, as for example, the water in a steam boiler as in the Ahrens Fire Engine, see page 126, Fig. 426, or in marine boilers, or forces cooling water through a surface condenser.

A centrifugal pump driven by an independent engine, see page 219, Fig. 497, is generally used for the latter purpose.

The annexed engraving, Fig. 454A, represents a circulating pump attached to a salt water evaporator and distiller for recovering fresh water at sea. The pump at the lower right-hand corner of the engraving takes salt water through the suction at the bottom and passes it upward through the condenser and overboard through the circulation discharge. _Any steam pump having a sufficient capacity may be used as a circulating pump._

ATMOSPHERIC PUMPS.

_The Bliss-Heath Atmospheric Pumping Engine_ represented by Fig. 455 is novel in its construction, consisting of a low-pressure, upright, tubular steam boiler, having a safety valve loaded to carry 1-1/2 lbs. steam pressure. The large cover lifts under 2 lbs. pressure, hence explosions cannot occur.

NOTE.—The safety valve is shown on the floor alongside of the hand
bar arranged to work the feed pump. Fig. 455.

The motor is a simple atmospheric engine operating a plunger pump and a single acting air pump.

The operation of this motor is almost noiseless.

The motive power is the normal pressure of the atmosphere (14.7 lbs. to the square inch), utilized by the formation of a vacuum in the power cylinder.

The air is expelled from the cylinder by admitting steam without appreciable pressure, _i.e._, to balance that of the atmosphere, after which the steam exhausts into the surface condenser, in which a constant vacuum is maintained. Steam is then admitted automatically into the power cylinder, breaking the vacuum and imparting to the piston the required impetus. _This principle is identical with that of the ordinary condensing steam engine_, with the exception of the very low steam pressure in this connection.

This engine can be operated satisfactorily in combination with an ordinary house-heating boiler (low pressure), hence the expense of running it is very low during the steam-heating season. During the summer months the boiler connected with this engine can be used advantageously.

The bearings are self-oiling, and the cylinder condensation furnishes ample protection for the inside of the engine cylinder. There are no leather packings to burn out, and this is remarkably free from the objections to the older types of caloric engines.

These pumps when required will force a proportionate quantity of water to a greater height than fifty feet, upon which the following table is based:

TABLE OF APPROXIMATE DIMENSIONS AND CAPACITIES.

=======+==========+=============+=============+========+=========
| Gallons | Size of | Approx. | | Size of
Size | Per Hour | Suc. & Dis. | Floor | Height | Smoke
Number | 50 ft. | Pipes. | Space | | Pipe
-------+----------+-------------+-------------+--------+---------
1 | 600 | 1-1/4″ | 43″ × 26″ | 53″ | 5″
-------+----------+-------------+-------------+--------+---------
2 | 1200 | 1-1/2″ | 43″ × 26″ | 58″ | 6″
-------+----------+-------------+-------------+--------+---------
3 | 2000 | 2″ | 48″ × 30″ | 63″ | 7″
-------+----------+-------------+-------------+--------+---------
4 | 3000 | 2-1/2″ | 48″ × 30″ | 63″ | 7″
-------+----------+-------------+-------------+--------+---------

AMMONIA OR ACID PUMPS.

In pumping ammonia it is of the greatest importance that this mechanism be simple and compact owing to the peculiar properties—oftentimes dangerous—inherent to ammonia.

The plain slide valve with crank, shaft and fly-wheel probably is less liable to give trouble than many of the other styles of pumps, _and a full stroke is always assured_.

The pump here presented (Fig. 456) occupies little floor space and is easily accessible; the bucket plunger is used and also a slotted yoke in place of a connecting rod.

The column is in two parts bolted together. In case of accident to either part duplicates may be quickly substituted.

THE WOOD PROPELLER PUMP.

The pump shown herewith lifts the water by propeller screws or “runners,” each consisting of two half-circular inclined blades fastened to a shaft at intervals of 3 to 5 feet, and of slightly less diameter than the casing, so as to revolve freely within it.

Experiments have demonstrated that more water can be raised with a given speed by putting the runners close together near the bottom of the pump.

A bearing for the shaft is placed immediately underneath each of the runners, and held in position by a set of spring “guides” attached lengthwise to the well-casing. These guides interrupt the whirling motion of the water as it is thrown upward by the runners, and turns it back in the opposite direction, thereby delivering it into the revolving runners in a direction opposite their motion. By this method the whirling motion of the water is utilized and the capacity of the pump largely increased without a proportional increase of power to run it.

With this pump, water may be raised from several hundred feet below the surface by extending the shaft and runners down the well-casing to the desired depth; it being always necessary to submerge the lower runner. As the shaft rotates the lower runner lifts the water up to the runner above it, and so on to the next, until the water is delivered at or above the ground if desired; the distance depending upon the size and pitch of the runner, the number of runners, and the speed at which they are driven.

Speed is not increased for additional depth, because more runners are added, and this compounding of the runners increases the efficiency of the pump.

A ball bearing is placed over the stuffing-box to carry the entire weight of all the movable parts of the pump, and also the column of water. In deep wells cone roller bearings are used in place of the ball bearings.

The pumps are made to fit all sizes of wells and of any desired capacity. Runners of various pitches are made for the different sizes in order to suit the supply of water or the power available. If, after testing, the supply of water in the well is found to be limited, the runners are changed to raise the amount of water due to a given horse-power, then runners can be furnished with a pitch suited to lifting that particular amount of water.

For example, if one runner at a given speed, gives 10 pounds pressure per square inch, then two runners would give 20 pounds; three, 30 pounds, and so on. For this reason water may be elevated higher above the discharge with this pump than with a centrifugal, for it would require a higher rate of speed to lift a given amount of water 20 feet with one runner, than to lift the same amount 5 feet. Hence the advantage of compounding the runners as the lift is increased. The compounding of runners is one of the main features of success and efficiency of this pump.

Where the water is beyond the suction limit this pump can be used to raise the water to the surface, discharging into the suction of the force pump. In this manner, whatever surplus of power the propeller pump might have in raising the water to the surface, would be utilized in helping the water through the force pump.

The speed of rotary pumps is generally high, ranging from 800 revolutions per minute for the small sizes to 250 revolutions for the larger sizes. In a number of experiments made upon this form of pump the highest efficiency was obtained with pressures ranging from 30 to 50 pounds per square inch, and speeds ranging from 475 to 575 revolutions per minute. The average efficiency of the rotary pump is from 48 to 52 per cent.

THE SCREW PUMP.

The engraving herewith, Fig. 458, exhibits the general construction of the Quimby screw pump. The four screws that act as pistons in propelling the water are mounted in pairs on parallel shafts, and are so arranged that in each pair the thread of one screw projects to the bottom of the space between the threads of the opposite screws. The screw threads have flat faces and peculiarly undercut sides; the width of the face and the base of the thread being one-half the pitch. The pump cylinder fits the perimeters of the threads. Space enough is left between the screws and the cylinder and between the faces of the intermeshing threads to allow a close running fit without actual contact. There is no end thrust of the screws in their bearings, because the back pressure of the column of liquid is delivered through the suction, S, at the middle of the cylinder, therefore the endwise pressure upon the screws in one direction is exactly counterbalanced by a like pressure in the opposite direction.

The suction connection opens into a chamber underneath the pump cylinder. The suction liquid passes through this chamber to the two ends of the cylinder and is forced from the ends toward the center by the action of the two pairs of intermeshing threads; the discharge being in the middle of the top of the cylinder, as shown at D. The power to drive the pump is applied to one of the shafts, and the second shaft is driven by means of a pair of gears, shown at G.

The pump has no internal packing, no valves and no small moving parts. The only packing is in the stuffing-boxes where the two shafts pass through the cylinder head.

Whether driven by a belt, an electric motor, or a steam engine, the driving power is applied directly and without the loss due to intermediate mechanism; as the screws are not in contact with the cylinder or with each other, the consequent absence of wearing surfaces gives the pump great durability.

These pumps have a high efficiency against a wide range of pressures: The power being applied direct, the thrust due to the back pressure of the column of liquid in the delivery pipe is balanced.

As the action of the screws on the liquid is continuous, the delivery is free from pulsation. By thus keeping the liquid in constant and uniform motion the efficiency of the pump is increased and the pump is made peculiarly suitable for certain specific purposes as there is no churning effect upon the liquids handled.

These pumps are much used in connection with hydraulic elevators by pumping directly into the elevator cylinders, as there is no pulsation. They are also used to pump oil into pipe lines and are driven by electric motors as well as by belts. For circulating pumps for brine and for fire purposes these pumps have certain peculiar advantages.

TABLE OF DIMENSIONS AND CAPACITIES OF THE QUIMBY SCREW PUMP.

=======+========+===========+============================+===================
| | | PIPING |EXTREME DIMENSIONS
| | +-------+----------+---------+-----+------+------
|Gallons |Revolutions| |Discharge | | | |
Size | per | per |Suction| from |Discharge|Width|Length|Height
|Minute | Minute | |Valve Hood| | | |
-------+--------+-----------+-------+----------+---------+-----+------+------
2 | 7-10 | 1200 | 1-1/4 | -- | 1 | 9 | 27 | 11
2-1/2 | 15-20 | 1200 | 2 | -- | 1-1/2 | 9 | 32 | 14
3 | 30-35 | 1200 | 2-1/2 | 2-1/2 | 2-1/2 | 10 | 38 | 16
3-1/2 | 70-85 | 1200 | 4 | 3 | 3 | 11 | 49 | 25
4 |140-170 | 1200 | 4 | 3 | 4 | 13 | 54 | 28
5 |200-245 | 1100 | 5 | 4 | 5 | 14 | 64 | 31
6 |275-350 | 900 | 6 | 5 | 6 | 17 | 75 | 37
7 |400-485 | 775 | 8 | 6 | 8 | 18 | 78 | 38
9 |650-800 | 725 |10 | 8 | 10 | 25 | 92 | 48
10 |825-1000| 575 |12 | 10 | 12 | 32 | 98 | 60
-------+--------+-----------+-------+----------+---------+-----+------+------
Dimensions in inches. Weights in pounds.

AERMOTOR
PUMPS

AERMOTOR PUMPS.

_Aer_ is the first element in many compound words of Greek origin meaning air, the air, atmosphere; in this connection it is combined with _motor_, defined as a machine which transforms the energy of water, steam, or electricity into mechanical energy—in this instance, is meant the changing of _the power of moving air or wind_ into mechanical energy.

_Wind is air put in motion._ There are two ways in which the motion of the air may arise. It may be considered as an absolute motion of the air, rarefied by heat and condensed by cold; or it may be only an apparent motion, caused by the superior velocity of the earth in its daily revolution.

When any portion of the atmosphere is heated it becomes rarefied, its specific gravity is diminished, and it consequently rises. The adjacent portions immediately rush into its place to restore the equilibrium. This motion produces a current which rushes into the rarefied spot from all directions. This is what we call wind.

_Meteorology_ is the science which treats of the atmosphere and its phenomena, particularly of its variations of heat and cold, _of its winds_, etc.

This is the great division of science to which one has to turn when searching for the first principles relating to the operation of _aermotor pumps_. The vast volumes of air which flow “hither and yon” are controlled by physical laws which act as accurately and unceasingly as those which control and hold in check the seemingly solid substance of the earth itself.

NOTE.—The portions north of the rarefied spot produce a north wind,
those to the south produce a south wind, while those to the east and
west in like manner, form currents moving in opposite directions.
At the rare spot, agitated as it is by winds from all directions,
turbulent and boisterous weather, whirlwinds, hurricanes, rain,
thunder and lightning, prevail. This kind of weather occurs most
frequently in the torrid zone, where the heat is greatest. The air,
being more rarefied there than in any other part of the globe, is
lighter, and, consequently, ascends; that about the polar regions is
continually flowing from the poles towards the equator, to restore
the equilibrium; while the air rising from the equator flows in an
upper current towards the poles, so that the polar regions may not be
exhausted.

To sum up all observations, it can be said with truth that the _sole force_ immediately concerned in causing the movements of the atmosphere, _is gravitation_.

So far as the prevailing winds are concerned it has been shown that where pressure is high, that is to say, _where there is a surplus of air, out of such a region winds blow in all directions_; and, on the other hand where pressure is low, or where there is a deficiency of air, _towards such a region_, winds blow from all directions in an in-moving special course.

This outflow of air currents from a region of air pressure upon a region of low pressure is reducible to a single principle, as already stated, viz., the principle of gravitation.

A regular east wind prevails about the equator, caused in part by the rarefaction of the air produced by the sun in his daily course from east to west. This wind, combining with that from the poles, causes a constant north-east wind for about thirty degrees north of the equator, and a south-east wind at the same distance south of the equator.

From what has now been said, it appears that there is a circulation in the atmosphere; the air in the lower strata flowing from the poles towards the equator, and in the upper strata flowing back from the equator towards the poles. It may be remarked, that the periodical winds are more regular at sea than on the land; and the reason of this is, that the land reflects into the atmosphere a much greater quantity of the sun’s rays than the water, therefore that part of the atmosphere which is over the land is more heated and rarefied than that which is over the sea. This occasions the wind to set in upon the land, as we find it regularly does on the coast of Guinea and other countries in the torrid zone. There are certain winds, called trade-winds, the theory of which may be easily explained on the principle of rarefaction, affected, as it is, by the relative position of the different parts of the earth with the sun at different seasons of the year, and at various parts of the day.

A knowledge of the laws by which these winds are controlled is of importance to the mariner. When the place of the sun with respect to the different positions of the earth at the different seasons of the year is understood, it will be seen that they all depend upon the same principle. The reason that the wind generally subsides at the going down of the sun is, that the rarefaction of the air, in the particular spot which produces the wind, diminishes as the sun declines, and, consequently, the force of the wind abates.

From its importance in practical meteorology _Buys Ballot’s law_ may be stated in these two convenient forms. (1) Stand with your back to the wind, and the center of the depression or the place where the barometer is lowest will be to your left in the northern hemisphere, and to your right in the southern hemisphere. This is the rule for sailors by which they are guided to steer with reference to storms. (2) Stand with the high barometer to your right and the low barometer to your left, and the wind will blow on your back, these positions in the southern hemisphere being reversed. It is in this form that the prevailing wind of any part of the globe may be worked out from the charts.

WIND POWER.

It is as _a source of energy_, to be classified with heat, weight of liquids, electricity, etc., that air in motion (as in a windmill) has a place as a prime mover.

_Prime movers_, or receivers of power, are those pieces or combinations of pieces of mechanism which receive motion and force directly from some natural source of energy. The point where the mechanism belonging to the prime mover ends and that belonging to the train for modifying the force and motion begins may be held to include all pieces which regulate or assist in regulating the transmission of energy from the source of energy.

_The useful work of the prime mover_ is the energy exerted by it upon that piece which it directly moves; and the ratio which this bears to the energy exerted by the source of energy is the efficiency of the prime mover.

In all prime movers the loss of energy may be divided into two parts, one being the unavoidable effect of the circumstances under which the machine necessarily works in the case under consideration; the other the effect of causes which are, or may be, capable of indefinite diminution by practical improvements. Those two parts may be denominated as _necessary loss and waste_.

The efficiency which a prime mover would have under given circumstances if the waste of energy were altogether prevented, and the loss reduced to necessary loss alone, is called _the maximum or the theoretical efficiency_ under the given circumstances.

In windmills, the air, being in motion, presses against, and moves four or five radiating vanes or sails, whose surfaces are approximately helical or screw shape, their axis of rotation being parallel, or slightly inclined in a vertical plane, to the direction of the wind.

_The velocity of the wind determines its pressure_, and the pressure of the wind against the sails of the windmill determines the power developed by the mill. A mill of small diameter acted upon by a high pressure develops as much power as a large mill working under a lower pressure.

_The mean average velocity of the wind for the entire United States_ is very nearly eight miles per hour. However, for large areas such as the great plains east of the Rocky Mountains, the mean average is about eleven miles per hour, and yet in certain small areas situated in the mountainous districts the mean average velocity is as low as five miles per hour. Therefore, in selecting and loading a mill, reference should be had to the wind velocity prevailing in that particular locality. In general, windmills loaded to operate in ten-mile winds can be depended upon to furnish a sufficient supply of water.

The variations in the velocity and pressure of the wind are considerable even within a brief time, and sometimes sudden and extreme. Winds of 100 miles per hour and upwards are on record. A very violent gale in Scotland registered by an excellent anemometer a pressure of 45 lbs. per square foot. During the severe storm at London, the anemometer at Lloyd’s registered a pressure of 35 lbs. to the square foot. The gauge at Girard College, Philadelphia, broke under a strain of 42 lbs. per square foot, a tornado passing at the moment within a quarter of a mile. At the Central Park Observatory, a wind was recorded of 28.5 lbs. pressure per square foot.

If the wind were to blow continuously a very small windmill would suffice to do a large quantity of work and no storage capacity would be required, but when it does blow it is “free” and experience dictates that a mill shall be erected sufficiently large to pump enough water, when the wind does blow, to last over, with the assistance of ample storage capacity.

Average hourly velocity of the wind at following stations of the U. S. Weather Bureau, given in miles per hour:

Albany, N. Y. 7
Alpena, Mich. 9
Atlanta, Ga. 9
Atlantic City, N. J. 10.3
Augusta, Ga. 4.2
Baltimore, Md. 6
Bismarck, N. D. 9.4
Boise City, Idaho 4.2
Boston, Mass. 10.2
Brownsville, Tex. 7.4
Buffalo, N. Y. 10
Cairo, Ill. 7.6
Cape Henry, Va. 12.7
Charleston, S. C. 8
Charlotte, N. C. 5.6
Chattanooga, Tenn. 5.5
Cheyenne, Wyo. 10.5
Chicago, Ill. 10.5
Cincinnati, Ohio 6.3
Cleveland, Ohio 9.6
Columbus, Ohio 7.6
Davenport, Iowa 8.5
Denver, Colo. 6.7
Des Moines, Iowa 7
Detroit, Mich. 8.7
Dodge City, Kan. 11.8
Duluth, Minn. 7
Eastport, Me. 0.6
El Paso, Tex. 6.3
Fort Grant, Ariz. 7
Fort Sill, I. T. 10.7
Galveston, Tex. 10.3
Grand Haven, Mich. 10.7
Hatteras, N. C. 14
Helena, Mont. 6.7
Huron, S. D. 11
Indianapolis, Ind. 6
Jacksonville, Fla. 6.7
Keokuk, Iowa 8
Key West, Fla. 9.8
La Crosse, Wis. 7.3
Leavenworth, Kan. 7.1
Little Rock, Ark. 3.6
Los Angeles, Cal. 4.7
Louisville, Ky. 7.3
Lynchburg, Va. 4
Madison, Wis. 10.2
Marquette, Mich. 8.7
Memphis, Tenn. 5.8
Mobile, Ala. 6.7
Montgomery, Ala. 5.1
New Haven, Conn. 8
New Orleans, La. 7.6
North Platte, Neb. 10.3
Olympia, Wash. 3.8
Omaha, Neb. 8.5
Oswego, N. Y. 9.6
Pensacola, Fla. 8.2
Philadelphia, Pa. 10
Pittsburg, Pa. 6
Portland, Me. 8
Portland, Ore. 5.3
Prescott, Ariz. 6.5
Red Bluff, Cal. 7
Roseburg, Ore. 5.3
Sacramento, Cal. 6.7
St. Louis, Mo. 10.3
St. Paul, Minn. 7.6
St. Vincent, Minn. 9.4
Salt Lake City, Utah 5.3
Sandy Hook, N. J. 14.5
San Diego, Cal. 5.6
San Francisco, Cal. 9.4
Savannah, Ga. 7
Shreveport, La. 5.6
Spokane Falls, Wash. 4.7
Springfield, Ill. 8.7
Vicksburg, Miss. 5.8
Washington, D. C. 6.5
Yuma, Ariz. 6
Yankton, S. D. 9

NOTE.—Windmills are erected to be operated by the lightest winds. A
wind which will carry off smoke will move a windmill; and the absence
of a wind of this force means a perfect calm. Mr. Corcoran says: “My
experience of thirty years teaches that a calm has seldom, if ever,
held sway in this part of the world for a longer period than three
days. Consequently, with a tank to hold a three days’ supply, it
becomes possible to pass over any number of calms.”

WIND POWER PUMPS.

Windmills can be divided into two general classes according to the inclination of the shaft: 1, _Horizontal mills_, in which sails are so placed as to turn by the impulse of the wind in a horizontal plane, and hence about an axis exactly vertical; and, 2, _vertical mills_, in which the sails turn in a nearly vertical plane, _i.e._, about an axis nearly horizontal.

On account of the many disadvantages connected with the horizontal windmill, it is seldom brought into use, being employed only in situations in which the height of the vertical sails would be objectionable, and this is liable to occur only in extraordinary cases. In this kind of mill six or more sails, consisting of plain boards, are set upright upon horizontal arms resting on a tower and attached to a vertical axis, passing through the tower at its middle part. If the sails are fixed in position, they are set obliquely to the direction in which the wind strikes them. Outside of the whole is then placed a screen or cylindrical arrangement of boards intended to revolve, the boards being set obliquely and in planes lying in opposite courses to those of the sails. The result is, from whatever direction the wind may blow against the tower, it is always admitted by the outer boards to act on the sails most freely in that half of the side it strikes, or from which the sails are turning away, and it is partly, though by no means entirely, broken from the sails which in the other quadrant of the side are approaching the middle line.

NOTE.—The great objections to the horizontal windmill are: first,
that only one or two sails can be effectually acted upon at the same
moment; and, secondly, that the sails move in a medium of nearly
the same density as that by which they are impelled, and that great
resistance is offered to those sails which are approaching the
middle. Hence with a like area of sails the power of the horizontal
is always much less than that of the vertical mill.

The illustration on page 184, Fig. 460, is a representation of the _Corcoran windmill_: it contrasts most interestingly with the same apparatus shown in Fig. 459—a windmill of the early part of the 17th century.

The figure below, 462, exhibits in detail _the rear view of the Corcoran mill with the governor_. As the speed of the wheel increases it swings the “tail” around, so as to bring the wheel at an angle with the direction of the wind; the latter failing to strike the blades squarely communicates less force, and in consequence the speed is diminished; in case of a very high wind the tail turns so as to present the wheel almost edgewise towards the direction of the blast.

NOTE.—A windmill of this type was erected at a station on the Long
Island R. R. to pump 5,000,000 gallons of water yearly. In order to
test the work of the windmill, a water meter was attached to the pump
during six months, and it was shown that the average work of the
windmill had been 22,425 gallons per day, 4,260,750 gallons during
the time stated and an average rate of 8,000,000 gallons per year.
The weight of water pumped was 16,168 tons gross and was raised to a
height of 66 feet, and the work was done without mishap with little
attention given to the pumping machinery.

Fig. 461 represents a Corcoran double action suction force pump. The base is hollow and contains the suction and discharge valves; a flange at the left-hand side receives the suction pipe while a corresponding flange on the right-hand side connects with the discharge pipe. An air chamber is attached to the discharge end. The valves may be reached by removing the bonnets on top of the base.

Fig. 463 is intended to represent an _Ideal steel tank tower_; the tank is herein located near the top. A _force pump_ is used where water is delivered into an elevated tank as in this case; a _lift pump_ is employed to discharge water at the spout and not to elevate above it.

_The common term “Windmill pump” distinguishes a wind power pump from a hand pump_, the difference being in an extension of the piston rod above the upper guide with a hole for connection with the pump rod from the windmill.

Such a pump, with the “pit-man” extending from the pump upwards into the tower, is shown in Fig. 465. This figure is introduced to show the tank connections with a regulator on the base of a four-post tower. The float in the water tank throws the mill in or out of gear according as the water rises or falls in the tank.

When the tank is filled with water it pulls the mill out of gear and stops the pump; as a result there can be no overflow or waste. The tank is thus not allowed to become empty and permit its drying apart, inducing leakage. But through the medium of the float in the tank, when the water has been lowered but a few inches, the mill is again put in gear and the tank refilled to the desired height, at which the float is set.

NOTE.—These have long been erroneously termed _windmill pumps_ dating
to the time when wind furnished the power for driving _the grist
mills used in grinding grain, etc._ More properly they may now be
named _windmotors_ or _airmotors_.

_The syphon pump_ here illustrated, Fig. 464, is used to force water from shallow wells to elevations. The cylinder or barrel is situated within the standard and very convenient for inspection. It has an air chamber which is detachable.

_The subject of tanks and cisterns_ is one almost vital to the successful operations of ordinary windmills, owing to the irregularity of the power to be utilized by the use of aermotors.

In another part of this work this important subject will be further explained and illustrated.

_One of the most valuable special features of this windmill is its governor._ It is so contrived that it insures immunity of the mill from injuries in destructive storms. It consists of a steel coiled spring of great resiliency, located at the base of the vane frame. Its strength is of such a character as to hold the wheel in the teeth of the wind under all ordinary conditions but is sure to yield under greater pressure.

USEFUL DATA

RELATING TO THE SIZES AND CAPACITIES OF PUMPING MILLS.

TABLE I.

=============+======+======+======+======+======+=======+=======+=======
Size of | 6 | 8 | 9 | 10 | 12 | 14 | 16 | 20
Pumping Mill | | | | | | | |
-------------+------+------+------+------+------+-------+-------+-------
No. Gals. | | | | | | | |
water raised | | | | | | | |
1 ft. hourly,| | | | | | | |
15-mile wind |10,000|20,000|24,000|35,000|68,000|110,000|160,000|300,000
-------------+------+------+------+------+------+-------+-------+-------

TABLE II.

======================+===+===+===+===+===+===+===+===+===+===+===+===
Average wind velocity,| | | | | | | | | | | |
miles per hour | 4 | 5 | 6 | 7 | 8 | 9 | 10| 11| 12| 13| 14| 15
----------------------+---+---+---+---+---+---+---+---+---+---+---+---
Co-efficient | 16| 8 | 5 | 3 | 2 |1.4|1. |.85|.70|.60|.54|.50
----------------------+---+---+---+---+---+---+---+---+---+---+---+---

TABLE III.

=========================+=====+=====+=====+=====+=====+=====+=====
Gallons hourly | 35 | 170 | 220 | 260 | 300 | 360 | 420
-------------------------+-----+-----+-----+-----+-----+-----+-----
Cylinder, diam. in. | 2 |2-1/4|2-1/2|2-3/4| 3 |3-1/4|3-1/2
-------------------------+-----+-----+-----+-----+-----+-----+-----
Discharge pipe, diam. in.|1-1/2|1-1/4|1-1/4|1-1/2|1-1/2| 2 | 2
-------------------------+-----+-----+-----+-----+-----+-----+-----

=========================+=====+=====+=====+=====+=====+======
Gallons hourly | 550 | 850 | 1200| 2200| 3400| 5000
-------------------------+-----+-----+-----+-----+-----+------
Cylinder, diam. in. | 4 | 5 | 6 | 8 | 10 | 12
-------------------------+-----+-----+-----+-----+-----+------
Discharge pipe, diam. in.| 2 |2-1/2|2-1/2|3-1/2| 4 | 5
-------------------------+-----+-----+-----+-----+-----+------

TABLE IV.

================================================================
COMPARATIVE POWER OF BACK-GEARED MILLS.
------------+-----+-----+-----+-----+------+------+------+------
Size of Mill|4-ft.|6-ft.|8-ft.|9-ft.|10-ft.|12-ft.|14-ft.|16-ft.
------------+-----+-----+-----+-----+------+------+------+------
Horse-Power |1/12 | 1/5 |3/10 | 2/5 | 3/5 | 1 | 1-3/5|2-3/5
------------+-----+-----+-----+-----+------+------+------+------

TABLE V.

==================================================
FORCE OF THE WIND IN POUNDS PRESSURE.
----------------+---+---+---+---+---+---+-----+---
Velocity Miles| 8 | 10| 12| 15| 20| 25| 30 | 40
----------------+---+---+---+---+---+---+-----+---
Force Pounds|1/3|1/2|3/4| 1 | 2 | 3 |4-1/2| 8
----------------+---+---+---+---+---+---+-----+---

TABLE VI.

=========================================
POWER OF THE WIND.
------------------+----------------------
Velocity per Hour.|Pressure per Sq. Foot.
10 Miles | 1/2 Lb.
15 „ | 1 „
20 „ | 2 Lbs.
25 „ | 3 „
------------------+----------------------

TABLE VII.

=================================================================
GROSS AND EFFICIENT POWER OF 12 AND 14 FOOT WINDMILLS.
-------------------------+----------+--------------+-------------
| Velocity | Gross | Net
SIZE OF MILL. | of Wind. | Horse-power. | Horse-power.
-------------------------+----------+--------------+-------------
12-Foot Ideal Power Mill | 10 Miles | 1/2 | 1/10
12 „ „ „ „ | 15 „ | 1 | 3/5
12 „ „ „ „ | 20 „ | 2 | 1-3/5
12 „ „ „ „ | 25 „ | 3 | 2-3/5
14 „ „ „ „ | 10 „ | 1 | 3/5
14 „ „ „ „ | 15 „ | 2 | 1-3/5
14 „ „ „ „ | 20 „ | 4 | 3-3/5
14 „ „ „ „ | 25 „ | 6 | 5-3/5
-------------------------+----------+--------------+-------------

The preceding tables are based upon tests of the _Sampson windmill_ as compiled by its makers, The Stover Manufacturing Co.; they deserve careful study by those planning the introduction of aermotors.

_The power of a windmill_ depends—first, on the diameter of the wheel; and second, on the velocity of wind. _To increase the diameter of the wheel is to increase its power_ in proportion to the area of the squares. Table I gives the horse-power of several sizes of mills working in a fifteen-mile wind: if the wind velocity be increased or diminished, the power of the windmill will increase or decrease in the ratio of the squares of the velocity. Table V will show the comparative power or force of the wind in velocities from eight to forty miles per hour for each square foot of surface.

_Rules for approximately determining size of windmill to use._

The daily water consumption must be given as a basis for calculation. Divide this by 8 to find the hourly capacity of windmill, as if loaded aright the mill will pump on an average eight hours daily.

_Multiply the quotient by total water lift in feet and with the co-efficient given in Table II._

The product will in Table I show what mill to use.

The size of the cylinder and discharge pipe will be found in Table III.

Table I gives the maker’s number of the pumping mill, and the number of gallons each will raise one foot high per hour, with a wind having a velocity of fifteen miles per hour. Example: No. 9 pump will raise 24,000 gallons of water one foot high in one hour. Now if the water is to be raised 50 feet then by dividing 24,000 by 50 the quantity raised becomes 480 gallons per hour.

From Table V it will be seen also that a wind velocity of fifteen miles per hour develops a power three times as great as an eight-mile wind, and a twenty-mile wind is twice as powerful as a fifteen-mile, or six times that of an eight-mile. Hence, _a small increase in velocity greatly increases the power of the windmill_, while a low velocity gives but little working force.

From Table VI it is seen that a twenty-five mile wind gives six times as much power as a ten-mile wind, but really gives twenty-six times _the net efficient power of the ten-mile wind_, therefore it will not be proper to calculate on using a power windmill in as low a velocity as ten miles.

From Table VII it is seen that the net efficient result is six times as great in a fifteen-mile wind as in a ten-mile wind, and sixteen times greater in a twenty-mile wind than in a ten-mile wind. Therefore, _power windmills give best results when working in fifteen to twenty-five mile winds_. A 12-foot power windmill working in a fifteen-mile wind will do more work than an average horse, and when working in a twenty-mile wind will do more work than two average horses.

_Example._—A person in Atlanta, Ga. uses 2,600 gallons of water
daily. He has a well in which the water stands 30 feet from ground
level. To obtain pressure, the water is to be elevated into a tank 50
feet above ground. 2,600 ÷ 8 = 325 gallons to be pumped hourly when
windmill works.

Average wind velocity at Atlanta is 9 miles per hour, answering to
coefficient 1.4 in Table II, and total water lift is 30 + 50 = 80
feet. 325 × 1.4 × 80 = 36,400 gallons.

If first estimate of 2,600 gallons daily was liberal, so that for
instance 2,400 gallons would be sufficient, Table I shows that a
10-foot mill can be used, but to keep on the safe side, choose a
12-foot mill. 325 gallons hourly gives us in Table III 3-1/4-inches
cylinder with 2-inches discharge pipe as proper sizes. If the 10-foot
mill is chosen take the 3-inch cylinder.

A 14-foot windmill working in a fifteen-mile wind will do more work than two average horses, and when working in a twenty-mile wind will do more work than four good horses, while in a twenty-five mile wind it will do more work than six good horses.

_Giving the above tables a practical application_, a little thought will disclose what a wealth of power stands unappropriated and ready at hand to do many of the drudgeries of work for which large expenditures are annually made.

The uses of power windmills are so well understood that it seems out of place to elaborate upon them; the brief space allowed to giving information as to the power of this class of mills when working in different wind velocities, is best expressed in tabular form, Table VI.

Fig. 466 represents the working barrel of a _deep well pump_, such as are used frequently in connection with the larger sizes of aermotors.

The tube is usually made of heavy brass—this is _drawn_ so perfectly, as to size and smoothness, that a re-boring is not needed.

The plunger is here shown with four cup leather packings, with one ball valve; the bottom valve is also a ball with the seat resting within a conical coupling at the bottom, this with a leather packing makes a water tight joint.

Should any accident happen to the bottom valve it may be withdrawn by lowering the sucker-rod until the threaded portion comes in contact with the nut underneath the plunger. By turning the sucker-rod the nut engages the thread on the top of the lower valve-cage. Then by withdrawing the sucker-rod both valves may be drawn up for examination or repairs.

ROTARY AND
CENTRIFUGAL
PUMPS

ROTARY PUMPS.

This class of pumps differs from the centrifugal pump, which is described and illustrated hereafter, in that it includes a _revolving piston_, while in the centrifugal pump there is a set of _revolving blades_ which acts upon the liquid in the same way as a fan acts upon the air; _the centrifugal pump receives the water in the center and throws it outward, while the rotary gathers the fluid up and leads it towards a central discharge_.

The rotary pump substantially corresponds to the pressure blower, and in many cases is simply the rotary engine reversed; while the centrifugal pump is analogous to the fan-blower. The functions of a rotary are almost identical with those of piston and power plunger pumps.

_The rotary pump on account of its cleanliness_ has been quite generally adopted for pumping all heavy liquids, such as starch, paint, soap, gummy oils, beer and hops, sewerage, bleachers, etc.

The rotary pump is used also in places where a piston or steam pump would be objectionable either on account of floor space occupied or for the reason that steam could not be had without too much expense for lifting and forcing water and other liquids which would not nor could not find their way through the tortuous and narrow passages of the average piston and plunger pumps.