SPRAYS AND OTHER MEANS OF CONTROL 



1889 



Agitators 



Agitators are a frequent source of 

 trouble in spraying outfits, especially in 

 power machines. Swinging paddles usu- 

 ally pose as agitators, or long rotary types 

 are used in the bottoms of round tanks 

 or barrels. These work very well in 

 small tanks or barrels but are a decided 

 failure in large tanks. The sliding agi- 

 tator is the type used ordinarily in most 

 power machines. Connections of the ag- 

 itators to power are made in various ways, 

 but the principle is much the same in 

 different makes. The amount of power 

 required to operate such an agitator is 

 enormous, in proportion to the agitation 

 one gets in an ordinary tank. Propeller 

 agitators are much more efficient than 

 other types, because of the higher speed 

 at which they may be run, their dur- 

 ability, simplicity, light weight, small 

 size, and neat appearance, all being in 

 their favor; besides possessing these qual- 

 ities, they agitate the spray liquid 

 thoroughly, and require less power to op- 

 erate them than any of the large, sliding 

 types of equal efficiency. Jet agitators 

 are often used on small hand pumps, but 

 they are always inefficient and give very 

 little agitation. A jet agitator, properly 

 constructed, would give fair agitation, but 

 I know of none which utilizes the shape of 

 the tank helping to agitate the solution. 



A number of hand pumps are patterned 

 after the ordinary water force pump With 

 these the stuffing box is the source of so 

 much friction that barrel pumps of this 

 type should be avoided. Simpler types 

 of pumps, without a stuffiing-box, should 

 be selected. Plungers with a plunger- 

 cup, or inside plunger-packing, require 

 less power to operate them. Outside plun- 

 ger-packing, or a stuffing box on the out- 

 side of the plunger, is another method 

 used in order to facilitate packing and 

 obviate trouble. Double-acting pumps 

 must necessarily have thei stuffing-box 

 and plunger-packing too, but some of the 

 strongest and most durable power pumps 

 are of this type. Of the two latter types 

 I have no particular choice, as each has 

 its merits, and each requires about the 

 same amount of care. The simple, single- 



acting pump with a plunger-cup or plung- 

 er-packing on the outside or inside, re- 

 quires less attention than any of the other 

 types, and is preferable to the other types. 



Supply Tanks 



Supply tanks are of various shapes and 

 sizes, but the round-bottom tank is most 

 used because it is easy to build and easily 

 kept tight by merely tightening a few 

 nuts on the clamp rod. Hoop tanks al- 

 ways dry out and give trouble. Square, 

 rodded tanks are very good, but require 

 more tightening of rods when they be- 

 come leaky. They have some points of 

 superiority in case the ordinary types 

 of agitators are used, since these will 

 agitate the solution better when it is 

 driven into the corners of a square tank. 



J^ozzles 

 Nozzles are often a source of consid- 

 erable trouble to the operator of a spray- 

 ing outfit. Bordeaux nozzles throw an 

 uneven flat spray, which is too coarse for 

 most spraying. Vermorel types with med- 

 ium caps throw a narrow-angle, fine spray, 

 but they are of small capacity, are al- 

 ways catching on limbs and frequently 

 clogging. Pressure at the nozzle cap is 

 also much reduced by the narrow orifices 

 and tortuous channels through which the 

 liquid must pass. Nozzles utilizing the 

 principle of the whirl caused by the liquid 

 entering from the sides of the whirling 

 chamber, do not reduce so much the pres- 

 sure and force, and give a broader, finer 

 spray, without reducing the speed of the 

 liquid as it passes through the nozzle 

 cap. They also allow the use of much 

 larger orifices and abolish the trouble of 

 nozzle catching on limbs. This brings us 

 to the large types, which are made by a 

 number of the companies, and, so far as 

 I know, all of these types of large nozzles 

 are good. 



Factors Which Tend to Make a Nozzle 

 Throw an Even Spray 



One fault that manufacturers seem to 

 have overlooked is the tendency of the 

 large-type nozzle to throw the bulk of 

 the spray in one quarter of the circle. 

 This may be overcome by making more 

 supply holes through the plate or top of 



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