Vacuum excavation system and method for preventing blockages from forming therein

Abstract

Systems and methods for a vacuum excavator to prevent to formation of blockages know as spoil bridges are provided. The vacuum excavator includes a high vacuum blower that is coupled through a multi-stage airflow system that has a debris tank to which an excavation hose is coupled. A knuckle boom having two arm segments includes actuators to angularly position the arm segments, and hose roller assemblies that carry the excavation hose. The systems and methods control the angular position of the arm segments to control the flow curvature of the excavation hose from an excavation site to the debris tank in order to eliminate or reduce the occurrences of spoil bridges therein.

What is claimed is: 
     
         1 . A vacuum excavator, comprising:
 a high vacuum blower coupled through a multi-stage airflow system having a debris tank to which an excavation hose is coupled; and   a knuckle boom having a first arm segment carrying a first hose roller assembly and a second arm segment carrying a second hose roller assembly, a first angular position relative to horizontal of the first arm segment being controlled by a first actuator and a second angular position relative to the first arm segment being controlled by a second actuator; and   wherein the excavation hose is carried by at least one of the first hose roller assembly and the second hose roller assembly; and   wherein at least one of the first arm segment and the second arm segment are angularly positioned by at least one of the first actuator and the second actuator to control a flow curvature of the excavation hose from an excavation site to the debris tank.   
     
     
         2 . The vacuum excavator of  claim 1 , wherein the high vacuum blower provides a suction pressure of 27 inHg. 
     
     
         3 . The vacuum excavator of  claim 1 , wherein the first actuator controls the first angular position of the first arm segment between approximately 35° above and approximately 35° below horizontal. 
     
     
         4 . The vacuum excavator of  claim 1 , wherein the second actuator controls the second angular position of the second arm segment between 0° and approximately 100° relative to the first arm segment. 
     
     
         5 . The vacuum excavator of  claim 1 , wherein the first hose roller assembly includes two sets of rollers spaced along the first arm segment, each of the two sets of rollers including two hose contact rollers positioned at an angle relative to one another to support the excavation hose on either side of at least the bottom half of the circumference of the excavation hose. 
     
     
         6 . The vacuum excavator of  claim 5 , wherein the two sets of rollers are spaced along the first arm segment by at least two feet to control a bend radius of the excavation hose therebetween. 
     
     
         7 . The vacuum excavator of  claim 5 , wherein at least one of the two sets of rollers of the first hose roller assembly includes a third roller positioned horizontally above the two rollers. 
     
     
         8 . The vacuum excavator of  claim 5 , wherein the two sets of rollers are joined by a support member at the apex of the two rollers of each of the two sets of rollers. 
     
     
         9 . The vacuum excavator of  claim 1 , wherein the second hose roller assembly includes two sets of rollers spaced along the second arm segment, each of the two sets of rollers including two hose contact rollers positioned at an angle relative to one another to support the excavation hose on either side of at least the bottom half of the circumference of the excavation hose. 
     
     
         10 . The vacuum excavator of  claim 9 , wherein the two sets of rollers are spaced along the second arm segment by at least two feet to control a bend radius of the excavation hose therebetween. 
     
     
         11 . The vacuum excavator of  claim 9 , wherein at least one of the two sets of rollers of the second hose roller assembly includes a third roller positioned horizontally above the two rollers. 
     
     
         12 . The vacuum excavator of  claim 9 , wherein the two sets of rollers are joined by a support member at the apex of the two rollers of each of the two sets of rollers. 
     
     
         13 . The vacuum excavator of  claim 1 , wherein the knuckle boom is horizontally rotatable by approximately 180°. 
     
     
         14 . The vacuum excavator of  claim 1 , wherein the first roller assembly of the first arm segment is positioned approximately 4 feet from the debris tank to which the excavation hose is coupled. 
     
     
         15 . The vacuum excavator of  claim 1 , further comprising a high pressure air compressor for providing compressed air to enable air excavation. 
     
     
         16 . The vacuum excavator of  claim 1 , further comprising a water storage tank and high pressure water pump for providing high pressure water to enable hydro-excavation. 
     
     
         17 . The vacuum excavator of  claim 1 , wherein the multi-stage airflow system further comprises at least one cyclone filter and a final filter positioned between the debris tank and the high vacuum blower. 
     
     
         18 . A method of reducing the formation of a spoil bridge in an excavation hose of a vacuum excavator of  claim 1 , comprising the steps of:
 providing a high vacuum pressure through a debris tank to the excavation hose to extract spoils from an excavation site;   controlling a flow curvature of the excavation hose from the excavation site to the debris tank to reduce flow disruptions of the spoils extracted therethrough; and   wherein the step of controlling includes angularly positioning a first arm segment carrying a first hose roller assembly and a second arm segment carrying a second hose roller assembly, wherein the excavation hose is carried by at least one of the first hose roller assembly and the second hose roller assembly.   
     
     
         19 . The method of  claim 18 , wherein the step of angularly positioning the first arm segment comprises the step of angularly positioning the first arm segment between approximately 35° above and approximately 35° below horizontal. 
     
     
         20 . The method of  claim 18 , wherein the step of angularly positioning the second arm segment comprises the step of angularly positioning the second arm segment between 0° and approximately 100° relative to the first arm segment.