Email
Print
Gravity Feed - Liquid Delivery System
Sono-Tek's gravity-operated liquid delivery system is a low-cost, versatile design for use primarily with ultrasonic nozzle spray applications conducted in a laboratory settingor for feasibility testing.
The system is a self-contained assembly into which a Sono-Tek ultrasonic nozzle can be immediately installed. The liquid to be sprayed is placed in a vented reservoir that is raised well above the nozzle in order to provide a sufficient gravitational driving force to expel liquid from the reservoir and into the line supplying the nozzle.
Gravity-operated systems are the simplest of all liquid delivery systems. Their inherent simplicity offers several advantages:
- Compatible with virtually any liquid that does not chemically attack the high-density polyethylene reservoir
- Easy setup
- Simplicity - no moving parts or complex controls
Features:
- 1-gallon liquid reservoir
- Mounting stand for reservoir and ultrasonic nozzle
- Nozzle mounting clamp and height adjustment assembly
- In-line tubing pinch-valve for flow control (no liquid contact)
Operating Principle
The force of gravity is the sole driving factor in this system. Basic laws of physics tell us that the velocity of the stream exiting the nozzle (hence the flow rate) is proportional to the square root of the height differential (H) between the surface of the liquid and the exit orifice of the nozzle. In order to minimize variations in flow rate due to changes in H as the liquid level in the reservoir drops, a reservoir with minimal height and a broad base is used. As long as the distance between the bottom of the reservoir and the nozzle is considerably greater than the height of liquid contained within the reservoir, flow rate fluctuations can be minimized. Other factors play a major role in determining actual flow rates. These include tubing diameter and length, liquid properties such as viscosity,and the degree of closure on the pinch valve. Small diameter tubing and long lengths impede flow. High viscosity liquids do the same.Since the height differential is the only driving force,the degree of control in this type of system is quite limited.
LDGS06R1W
