Cleaning-in-place system and seal monitoring

Abstract

Apparatus and method for detecting seal failure of a sealed region within a conveyor component. A fluid line extends out of the sealed region, and a sensor is connected to the fluid line. A valve is connected subsequent to the sensor, and a fluid pump is connected subsequent to the valve. A controller is connected to the sensor, the valve, and the fluid pump. The sensor is external to the sealed region, and the valve is a solenoid valve. The sealed region is within an idler pulley that has a drum shell with an end lid affixed at an axial end thereof, and a shaft. The sealed region can be contained within a motorized drum, an idler pulley, or a hollow conveyor frame structure. A method detects seal failure by forming a sealed region bounded by a surface and a seal and by altering a fluid pressure, the time rate of change of which is monitored.

What is claimed is: 
     
         1 . A method for minimizing egress of contaminants from within a conveyor component due to a seal failure, the method comprising the steps of:
 forming a sealed area in a conveyor component bounded by one or more elements having a surface and one or more seals that communicate with one or more surfaces;   extending a fluid line out of said sealed region;   connecting said fluid line to a pump; and   withdrawing some fluid from within said sealed region, thereby creating a negative pressure within said sealed region.   
     
     
         2 . The method of  claim 1  wherein said conveyor component is an idler pulley. 
     
     
         3 . The method of  claim 1  wherein said conveyor component is a motorized drum. 
     
     
         4 . The method of  claim 1  wherein said conveyor component is a conveyor frame. 
     
     
         5 . The method of  claim 1  further comprising the step of detecting seal failure:
 by altering a fluid pressure within the sealed region, thereby creating a pressure differential between the sealed region and a reference pressure value; and 
 by monitoring a pressure differential between the sealed region and the reference pressure value. 
 
     
     
         6 . The method of  claim 5 , wherein the reference pressure value corresponds to a fluid pressure of an ambient environment outside said sealed region. 
     
     
         7 . The method of  claim 5 , wherein the reference pressure value is adjustable. 
     
     
         8 . The method of  claim 5 , wherein the fluid is withdrawn from the sealed region at a determinable rate of fluid withdrawal. 
     
     
         9 . The method of  claim 8 , wherein the determinable rate of fluid withdrawal is determined as a function of the physical and environmental characteristics of the seal. 
     
     
         10 . The method of  claim 9 , wherein the physical and environmental characteristics of the seal correspond to temperature variation and gas permeability. 
     
     
         11 . The method of  claim 8 , wherein there are provided the steps of monitoring a fluid pressure level in the sealed region and determining a time rate of change of said fluid pressure level in the sealed region. 
     
     
         12 . The method of  claim 8 , wherein there is provided the step of identifying an excessive rate of change of said fluid pressure level in the sealed region. 
     
     
         13 . The method of  claim 12  wherein there is provided the step of increasing the rate of withdrawal of said fluid from the sealed region over the predeterminable rate. 
     
     
         14 . The method of  claim 13 , wherein said step of increasing the rate of withdrawal of said fluid from the sealed region comprises the step of varying a reference pressure value. 
     
     
         15 . The method of  claim 5 , wherein there is provided the step of monitoring a rate of fluid flow in said fluid line wherein said monitoring of pressure differential is accomplished by monitoring the rate of fluid flow in said fluid line. 
     
     
         16 . The method of  claim 15 , wherein, when the rate of fluid flow in said fluid line exceeds a predetermined rate of fluid flow, a seal fault condition is indicated. 
     
     
         17 . The method of  claim 16  whereupon when said seal fault condition is indicated there is a further step of increasing the rate of fluid flow to maintain a reduced fluid pressure in the sealed region. 
     
     
         18 . The method of  claim 1 , wherein there are provided the steps of:
 inserting a fluid into the sealed region, whereby the pressure in the sealed region is made greater than the reference pressure value;   monitoring a variation in said fluid pressure within the sealed region;   determining a time rate of change of the variation in said fluid pressure within the sealed region; and   identifying a fault condition in response to said step of determining a time rate of change of the variation in said fluid pressure.   
     
     
         19 . The method of  claim 1  wherein the fluid line is extended out of the sealed region through a central shaft of the conveyor component. 
     
     
         20 . The method of  claim 1 , wherein there are provided the steps of:
 coupling said fluid line to a sensor;   further coupling said fluid line to a valve subsequent the sensor; and   subsequently coupling said valve to the pump, to enable the displacement of fluid between the sealed region and ambient environment and to enable measurement of the pressure differential between the sealed region and the ambient environment.   
     
     
         21 . The method of  claim 20 , wherein
 activating the pump and opening said valve accomplishes a fluid transfer; and   closing said valve, whereupon said sensor is isolated from the pump, enables said sensor to measure the pressure in said sealed region.   
     
     
         22 . The method of  claim 1  wherein there are provided the steps of:
 mounting a sensor internal to the sealed region; 
 coupling the fluid line to a valve; and 
 subsequently coupling said valve to the pump, to enable the displacement of fluid between said sealed region and ambient environment and to enable measurement of the pressure differential between said sealed region and the ambient environment.