Question

An air blast of sprayers is to be operated at 3 km/hour and desired application rate is 18 l/tree. The tree spacing is 9*9 m and nozzle delivers 5 l/min at operating pressure of 4*10^5 N/m^2. How many nozzles would be needed?

(a) 10

(b) 20

(c) 30

(d) 40

I have been asked this question in quiz.

The doubt is from Plant Protection Equipments in portion Plant Protection Equipments of Farm Machinery

Answer 1

The correct option is (b) 20

The explanation: Time of spraying/tree = \(\frac{spacing}{forward \, speed} = \frac{(application \, width)}{number \, of \, nozzles*discharge \, rate} \)

\(\frac{9*60}{3*1000} = \frac{18}{n*5} \)

n = \(\frac{18*3*1000}{9*60*5} \)

n = 20.