Device for injecting and mixing liquid fertilizer with water flow in a sprinkler system pipeline

Abstract

The invention relates to a device for mixing a liquid such as fertilizer with water flow in a sprinkler pipeline where the liquid is timely dispensed over a period of time from a fertilizer chamber into a mixing chamber for mixing with the water before re-entering the pipeline. The device has a flexible diaphragm that sealingly separates a mixing chamber from a fertilizer chamber. A central disk is fixedly carried by the diaphragm and is biased by a first spring that applies a restoring force upon displacement of the central disk. A valve seat on an axial extension of the central disk extending into the mixing chamber is so dimensioned and proportioned to seat a pin holder fixed to an adjuster holder upon engagement by the pin holder. The adjuster holder is responsive to a second spring and the water pressure in the mixing chamber. A restrictor pin carried by the pin holder is displaced upon compression of the second spring to permit communication between fluid in the fertilizer chamber and mixing chamber when sufficient water pressure compresses the second spring. When the water flow is sufficiently reduced, the accompanying reduction in the water pressure will permit the second spring to expand and seat the pin holder in the valve seat thereby preventing further flow of the liquid from the fertilizer chamber into the mixing chamber.