Drip line and emitter and methods relating to same

Abstract

An irrigation emitter and drip line, and methods relating to same, are provided for reducing the flow and pressure of fluid via an emitter or plurality of emitters defined by two concentric tubes. In one form, the first tube defines an emitter inlet and connected pressure-reducing flow channel and the second tube is extruded over the first tube to enclose the emitter inlet and flow channel and defines an outlet connected to an end of the flow channel opposite the inlet to create an emitter for converting fluid flowing at a high flow rate in the lumen and at the first end of the inlet to a fluid with a low flow rate at the outlet of the emitter. In another form, a drip line is provided having a plurality of such emitters. Various other forms and methods relating to the emitter and drip line are also disclosed.

What is claimed is: 
     
         1 . An irrigation drip emitter for converting fluid flowing at a high flow rate to a low flow rate, comprising:
 a first extruded tube layer defining an inlet and a pressure-reducing flow channel on an exterior surface thereof with the inlet and flow channel each having first and second ends and the second end of the inlet being connected to the first end of the flow channel, and the first end of the inlet opening to an inner lumen defined by an inner surface of the first tube layer and sized to receive a desired amount of pressurized fluid from the inner lumen; and   a second tube layer extruded over the first tube layer and enclosing the inlet and flow channel, the second tube layer defining an outlet connected to the second end of the flow channel so that the flow channel extends between the inlet and outlet to create an emitter for converting fluid flowing at a high flow rate in the lumen and at the first end of the inlet to a fluid with a low flow rate at the outlet of the emitter.   
     
     
         2 . An irrigation drip emitter according to  claim 1  wherein the inlet defined by the first tube layer comprises an elongated bore that extends at the first inlet end into the inner lumen so that the fluid received at the inlet comes from a region other than at a circumferential periphery of the lumen adjacent the inner surface of the first tube. 
     
     
         3 . An irrigation drip emitter according to  claim 2  wherein at least one of the inner and outer tube layers is of variable thickness with a thickened portion being positioned proximate to at least one of the inlet, flow channel and outlet, the thickened portion being thicker then a remaining portion of the inner and outer tube layers. 
     
     
         4 . An irrigation drip emitter according to  claim 3  wherein the portion of the inner tube layer defining the inlet and flow channel is thicker than the remaining portion of the inner tube layer and the outer tube layer is of generally constant thickness. 
     
     
         5 . An irrigation drip emitter according to  claim 3  wherein the portion of the outer tube layer enclosing the inlet and flow channel is thicker than the remaining portion of the outer tube layer. 
     
     
         6 . An irrigation drip emitter according to  claim 1  wherein the inner tube layer is made of an elastomeric material capable of deflecting into the flow channel in response to an increase in pressure of the pressurized fluid traveling through the inner lumen thereby reducing the cross-sectional area of the flow channel as fluid pressure increases. 
     
     
         7 . An irrigation drip emitter according to  claim 6  wherein at least one of the inner and outer tube layers defines baffle walls that form at least a portion of the flow channel and the deflection of the elastomeric material into the flow channel further causes at least a portion of the baffle walls to move and effectively lengthen the flow channel to compensate for increasing fluid pressure. 
     
     
         8 . An irrigation drip emitter according to  claim 6  wherein at least one of the inner and outer tube layers defines stops or obstructions for preventing at least a portion of the inlet and at least a portion of an outlet area from completely collapsing in response to increasing fluid pressure. 
     
     
         9 . An irrigation drip emitter according to  claim 8  wherein the stops or obstructions are posts extending from a surface of the at least one of the inner and outer tube layers for preventing the at least a portion of the inlet and the at least a portion of the outlet area from completely collapsing in response to increasing fluid pressure. 
     
     
         10 . An irrigation drip emitter according to  claim 6  wherein the inner tube layer further defines ribs positioned proximate to the inlet for allowing the inlet to partially, but not completely, collapse in response to increasing fluid pressure in order to compensate for fluctuations in fluid pressure. 
     
     
         11 . An irrigation drip emitter according to  claim 1  wherein the inner tube layer defines a plurality of additional inlets and pressure-reducing flow channels on the exterior surface thereof, each additional inlet and pressure-reducing flow channel having first and second ends, with the second end of each additional inlet being connected to the first end of one of the additional pressure-reducing flow channels to form an inlet and corresponding flow channel, and the first end of each additional inlet opening to the inner lumen defined by the inner surface of the first tube layer and sized to receive a desired amount of the pressurized fluid from the inner lumen, with each inlet and corresponding flow channel being space apart from the other inlets and corresponding flow channels at predetermined intervals; and
 a second tube layer extruded over the first tube layer and enclosing the additional inlets and flow channels, the second tube layer defining a plurality of outlets with each outlet connected to the second end of one of the corresponding flow channels so that the corresponding flow channel extends between one inlet and one outlet to create a drip line having a plurality of emitters for converting the fluid flowing at the high flow rate in the lumen and at the first end of the inlets to fluid with the low flow rate found at any of the outlets. 
 
     
     
         12 . An irrigation drip emitter according to  claim 1  wherein the pressure-reducing flow channel defined by the first extruded tube is recessed into the exterior surface of the first extruded tube. 
     
     
         13 . An irrigation drip emitter according to  claim 1  wherein the pressure-reducing flow channel defined by the first extruded tube is formed by a wall extending from the exterior surface of the first extruded tube. 
     
     
         14 . An irrigation drip emitter according to  claim 1  wherein at least a first portion of the inlet or pressure-reducing flow channel is recessed into the exterior surface of the first extruded tube and at least a second portion of the inlet or pressure-reducing flow channel is formed by a wall extending from the exterior surface of the first extruded tube. 
     
     
         15 . An irrigation drip line comprising:
 a first extruded tube layer defining a plurality of inlets and pressure-reducing flow channels on an exterior surface thereof with each pressure-reducing flow channel being located proximate to one of the plurality of inlets, the plurality of inlets opening to an inner lumen defined by an inner surface of the first tube layer and sized to receive pressurized fluid from the inner lumen; and   a second tube layer extruded over the first tube layer and enclosing the plurality of inlets and flow channels, the second tube layer defining a plurality of outlets with each outlet positioned adjacent to one of the proximate flow channels on an end of the flow channel opposite one of the plurality of inlets so that the flow channel extends between one of the plurality of inlets and one of the plurality of outlets to create an emitter for reducing the pressure and flow of fluid received at the plurality of inlets by the time the fluid is discharged through the plurality of outlets.   
     
     
         16 . A method of manufacturing a drip line comprising:
 extruding a first tube layer having inner and outer surfaces and defining an inner lumen through which fluid may flow;   embossing a plurality of inlets and pressure-reducing flow channels having first and second ends on an exterior surface of the first extruded tube layer, with each pressure-reducing flow channel being connected to one of the plurality of inlets at the first end each of the pressure-reducing flow channels to form a corresponding flow channel for each inlet, and the plurality of inlets opening to the inner lumen defined by the inner surface of the first extruded tube layer and sized to receive pressurized fluid from the inner lumen;   extruding a second tube layer over the first tube layer to enclose the plurality of inlets and flow channels; and   making outlet openings in the second extruded tube layer near the second end of each pressure-reducing flow channel so that the flow channel extends between and connects the inlet and outlet of one of the plurality of inlets and outlets to form an emitter for reducing the pressure and flow of the pressurized fluid received at the inlet by the time the fluid is discharged through the plurality of outlets.   
     
     
         17 . A method according to  claim 16  wherein extruding the first tube layer comprises extruding a first tube layer having variable wall thickness, with a first thickened wall portion and a second thinner wall portion, and embossing comprises embossing the plurality of inlets and pressure-reducing flow channels into the first thickened wall portion of the first extruded tube layer. 
     
     
         18 . A method according to  claim 16  wherein embossing the plurality of inlets and pressure-reducing flow channels includes pressing the inlet opening into the outer surface of the first extruded tube layer to form an inlet that projects into the inner lumen of the first extruded tube layer so that the fluid received at the inlet comes from a region other than at a circumferential periphery of the lumen adjacent the inner surface of the first tube. 
     
     
         19 . A method of manufacturing a drip line comprising:
 extruding an inner tube having inside and outside surfaces and defining an inner lumen through which fluid may flow;   applying a male die to the outside surface of the inner tube and a corresponding female die to the outside surface of the inner tube in alignment with the male die to form a raised wall extending from the outside surface of the inner tube; and   extruding an outer jacket over the inner tube to enclose at least a portion of the raised wall to form an emitter having an inlet open to the inner lumen of the tube and an outlet opening through the outer jacket, with the flow passage extending between the inlet and outlet.