J indicates the connecting pipes between the receiver, air filters, and pump, and it should be noted they are considerably larger than those on the suction end C, this being necessary to allow for the expansion of the air under vacuum.
K is the reciprocating air pump, driven electrically by the motor M through large helical gear wheels, which act as flywheels and are helpful in equalizing the torque required by the pump.
L is the outlet pipe for the air as it is exhausted from and by the pump.
Fig. 20.—Floating Pneumatic Transport Plant; 200-250 Tons per hour.
Fig. 21.—Portable Pneumatic Plant on Railway Truck.
This plant is simple, but every possible modification can be added that circumstances make desirable; such as discharging on to a belt conveyor, for feeding the silos or other storage bins.
Where grain is bought by bulk it would be necessary to check the weight, and in this case an automatic weigher would be installed, into which the material would be discharged from the receiver. With a bag filter the collected dust can also be weighed, the total weight being then obtained by addition.
Typical Floating Plant. The most popular development of the above type of plant is the floating plant, designed for erection on a hulk, or barge, and intended to suck grain from an ocean-going steamer and discharge it into barges or lighters on the other side of the discharging plant, as indicated in Fig. 20. The plant shown is one of many in actual operation and its construction may be followed by reference to the description of the plant shown in Fig. 19, the same index letters being used in each case. One great advantage of floating plants is that the difference in height due to tides is of no consequence.