Gas Seal Column Pump for Elevated Temperature Applications

Abstract

The gas seal column pump may comprise a pump drive, a gas seal column with a corrosion resistant telescoping liner, a seal gas control box, and a pump. A drive motor of the pump drive, the gas seal column, and the pump may comprise a sealed, vertically-oriented, pumping system where the gas seal column is operable to replace mechanical seals around a drive shaft that couples the drive motor to the pump. A pressurized seal gas pumped into the gas seal column may displace corrosive fumes and the product being pumped. An unsealed pump drive motor may be used for certain applications. The vertical length of the telescoping liner may be controlled to mitigate interference with pump operation. Responsive to inputs from the level sensors, a seal gas control box may regulate the pressure of the seal gas using a plurality of valves.

What is claimed is: 
     
         1 . A gas seal column apparatus comprising:
 a pump drive motor, a sealed housing further comprising a gas seal column and a pump;   an auxiliary impellor coupled to a main impeller of said pump where said auxiliary impellor constitutes a hydrodynamic seal;   where the gas seal column, and the pump are sealed to one another to comprise a sealed, vertically-oriented, pumping system in a sealed pump envelope;   where the pump drive motor is connected to said sealed pump envelope;   where the gas seal column encases a drive shaft between said drive motor and said pump within said sealed pump envelope and is operable to replace mechanical seals and packing seals around a drive shaft that couples the drive motor to the pump.   
     
     
         2 . The apparatus according to  claim 1   where the gas seal column comprises gas inlet pipe connection through which the seal gas enters the gas seal column;   where the seal gas comprises a gas outlet pipe connection through which the seal gas exits the gas seal column via a purge gas discharge valve;   where the seal gas within the gas seal column displaces the corrosive fumes and the product;   where pressure of the seal gas is increased and decreased to control a product level within the gas seal column.   
     
     
         3 . The apparatus according to  claim 2   where the gas seal column comprises a plurality of level sensors which detect the product level within the gas seal column;   where the plurality of level sensors are positioned at differing heights within the gas seal column.   
     
     
         4 . The apparatus according to  claim 3   where the plurality of level sensors comprises a first level sensor, a second level sensor, a third level sensor, and a fourth level sensor;   where the first level sensor is located at the lowest level of the gas seal column and above the lowest level of product needed for the pump to prime and when activated signals that the product has entered the gas seal column and the pump is primed for operation;   where the second level sensor is located above the first level sensor and when activated signals that an increase in the pressure of the seal gas is needed;   where the third level sensor is located above the second level sensor and when activated signals that a further increase in the pressure of the seal gas is needed and closes the purge gas discharge valve to further aid in increasing seal gas pressure;   where the fourth level sensor is located above the third level sensor and when activated initiates a controlled shutdown of the pump or the entire system.   
     
     
         5 . The apparatus according to  claim 1  further comprising
 where the gas seal column comprises a plurality of splash quieting discs, a plurality of anti-rotation panels, or combinations thereof to control motion of the product within the gas seal column. 
 
     
     
         6 . The apparatus according to  claim 3   a seal gas control box to monitor the product level, to report the product level, and to control the product level and the continued operation of the pump;   where the seal gas control box monitors the product level via inputs from the plurality of level sensors.   
     
     
         7 . The apparatus according to  claim 6   where the seal gas control box controls the product level by opening and closing a purge gas valve, a first gas valve, a second gas valve, the purge gas discharge valve, or combinations thereof.   
     
     
         8 . The apparatus according to  claim 1   where the pump comprises, an auxiliary impellor coupled to a main impellor;   where the auxiliary impellor is larger in diameter than the main impeller;   where the auxiliary impellor is located closer to the gas seal column than the main impeller;   where the auxiliary impellor is operable as a hydrodynamic shaft seal to prevent the flow of the product into the gas seal column during pumping operations.   
     
     
         9 . The apparatus according to  claim 1   where the pump drive motor comprises a sealed motor or unsealed motor suitable to drive said pump.   
     
     
         10 . The apparatus according to  claim 9 ,
 where the pump drive motor comprises any style of motor suitable to drive a pump and the top mounting panel of the gas seal column is modified to accept a gas shaft seal, where said gas shaft seal fully seals the gas seal column and pump envelope combination.   
     
     
         11 . The apparatus according to  claim 3 ,
 further comprising a sealed, telescoping lined gas seal column for elevated temperature conditions   where the gas seal column pump comprises a pump drive, a gas seal column with telescoping liner, and a pump;   where a drive motor of the pump drive, the gas seal column, and the pump compromise a sealed, vertically-oriented, pumping system; where said gas seal column liner is sealed, telescoping lined gas seal column for elevated temperature conditions that adjusts vertically in response to elevated temperature operations;   where said gas seal column liner is corrosion resistant;   where the gas seal column is operable to replace mechanical seals and packing seals around a drive shaft that couples the drive motor to the pump.