Methods and apparatus for controlling power in vapor jet vacuum pumps

Abstract

Methods and apparatus for controlling power supplied to vapor jet vacuum pumps are provided. A vapor jet vacuum pumping system includes a vapor jet pump having an inlet port, an exhaust port, a jet assembly and an boiler, the boiler including a heater, and a power controller for automatically controlling power supplied to the heater in response to at least one control parameter. The power may be controlled in response to a programmed sequence, to a sensed pressure in a process chamber, to control signals from a process control system, or to combinations of these control parameters.

What is claimed is:  
     
         1 . A vapor jet vacuum pumping system comprising: 
 a vapor jet pump having an inlet port, an exhaust port, a jet assembly and boiler, said boiler including a heater; and    a power controller for automatically controlling power supplied to said heater in response to at least one control parameter.    
     
     
         2 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein the control parameter comprises a programmed sequence of power levels.  
     
     
         3 . The vapor jet vacuum pumping system as defined in  claim 2 , wherein the programmed sequence of power levels is adjustable.  
     
     
         4 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said power controller is configured for controlling power supplied to said heater in response to a sensed pressure in a process chamber being pumped by said vapor jet pump.  
     
     
         5 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said power controller is configured for controlling power supplied to said heater in response to control signals from a process control system.  
     
     
         6 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said power controller is configured for controlling power supplied to said heater in response to a combination of two or more control parameters.  
     
     
         7 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said power controller is configured for controlling power supplied to said heater at one of two or more discrete power levels.  
     
     
         8 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said power controller is configured for controlling power supplied to said heater over a continuous range of power levels.  
     
     
         9 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said heater includes two or more heater sections and wherein said power controller is configured for selectively energizing one or more of said heater sections.  
     
     
         10 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said power controller is configured for synchronizing increased power input to said heater with increased load on said vapor jet pump.  
     
     
         11 . The vapor jet vacuum pumping system as defined in  claim 1 , wherein said control parameter is representative of load on said vapor jet pump.  
     
     
         12 . A method for a vacuum pumping of a process chamber, comprising the steps of: 
 vacuum pumping a process chamber with a vapor jet pump having a boiler including a heater; and    automatically controlling power supplied to said heater in response to at least one control parameter that is representative of load on the vapor jet pump.    
     
     
         13 . The method as defined in  claim 12 , wherein the step of controlling power comprises controlling power supplied to said heater in accordance with a programmed sequence of power levels.  
     
     
         14 . The method as defined in  claim 12 , wherein the step of controlling power comprises controlling power supplied to said heater in response to sensed pressure in the process chamber.  
     
     
         15 . The method as defined in  claim 12 , wherein the step of controlling power comprises controlling power supplied to said heater in response to control signals from a process control system.  
     
     
         16 . The method as defined in  claim 12 , wherein the step of controlling power comprises controlling power supplied to said heater in response to a combination of two or more control parameters.  
     
     
         17 . The method as defined in  claim 12 , wherein the step of controlling power comprises controlling power supplied to said heater at one of two or more discrete power levels.  
     
     
         18 . The method as defined in  claim 12 , wherein the step of controlling power comprises controlling power supplied to said heater over a continuous range of power levels.  
     
     
         19 . The method as defined in  claim 12 , wherein said heater includes two or more heater sections and wherein the step of controlling power comprises energizing one or more of said heater sections.  
     
     
         20 . A method for controlling a vapor jet pump having an inlet port, an exhaust port, a jet assembly, and a boiler, said boiler including a heater, the method comprising: 
 automatically controlling power supplied to the heater in accordance with a control algorithm.