Studies on the Pumping Performance of Power Sprayer (IV)

Movement of Suction and Discharge Valves and Pumping Performance

Abstract

It was the purpose of this study to find out the movement of suction and discharge valves, and a relation between each valve and pumping performance of power sprayer.
The lift of each valve was measured by the variation of inductance
The experiment was performed about the each valve having the three kinds of spring varied the spring constant.
For the actual operating of power sprayer, the movement of suction and discharge valves, the pressure in cylinders and suction port, were measured. In order to calculate the volumteric efficiency and pump efficiency, the discharge flow, the discharge pressure and rotational speed were meeasured.
The following results were obtained.
1. The movement of suction and discharge valves, the pressure variation in cylinders and the fluctuation of suction pressure per one revolution were shown in Fig 3.
2. The valve delays in closing and opening were found as a rotational angle of crank shaft. On each valve, the valve delays increased with the spring constant of valve spring was the smallest, the valve delay was the greatest in each valve.
3. On the discharge valve, the maximum valve lift increased with the increase of rotational speed.
4. The volumetric efficiency and pump efficiency were shown in Fig 8.
When the spring constant was the smallest, the volumetric efficency was dropped in the range of rotational speed above 600rpm.