Pump system including a controller

Abstract

A method of controlling a liquid ring pump in a pump system includes monitoring a vacuum pressure of the liquid ring pump using a pressure transmitter configured to transmit a vacuum pressure signal to a controller in operative communication with the liquid ring pump. The method also includes maintaining a predetermined vacuum pressure in the liquid ring pump under variable vacuum flow demand within the pump system in response to the vacuum pressure signal by controlling, via instructions from the controller, a parameter of the liquid ring pump based on a comparison of the vacuum pressure signal to the predetermined vacuum pressure by the controller.

1 . A method of controlling a liquid ring pump in a pump system, the method comprising:
 monitoring a vacuum pressure of the liquid ring pump using a pressure transmitter configured to transmit a vacuum pressure signal to a controller in operative communication with the liquid ring pump;   maintaining a predetermined vacuum pressure in the liquid ring pump under variable vacuum flow demand within the pump system in response to the vacuum pressure signal by controlling, via instructions from the controller, a parameter of the liquid ring pump based on a comparison of the vacuum pressure signal to the predetermined vacuum pressure by the controller.   
     
     
         2 . The method of  claim 1 , wherein maintaining the predetermined vacuum pressure includes controlling a motor coupled to and configured to drive the liquid ring pump at different speeds based on the comparison of the vacuum pressure signal to the predetermined vacuum pressure by the controller, the motor being communicatively coupled and responsive to instructions from the controller. 
     
     
         3 . The method of  claim 2 , further comprising determining a rotational speed of the motor associated with maintaining the predetermined vacuum pressure based on the monitored vacuum pressure, and adjusting the rotational speed of the motor to match the determined rotational speed. 
     
     
         4 . The method of  claim 3 , further comprising adjusting the rotational speed of the motor only within a range between a predetermined maximum rotational speed and a predetermined minimum rotational speed. 
     
     
         5 . The method of  claim 1 , wherein maintaining the predetermined vacuum pressure includes modulating a flow rate of sealing liquid into the liquid ring pump. 
     
     
         6 . The method of  claim 1 , wherein monitoring the vacuum pressure includes monitoring an inlet vacuum pressure of the liquid ring pump. 
     
     
         7 . The method of  claim 1 , further comprising controlling a drain valve operatively coupled to the controller to automatically purge the liquid ring pump in response to one or more of the following:
 a timed schedule for draining the liquid ring pump having been reached;   a signal transmitted to the controller indicative of the liquid ring pump experiencing higher than normal vibration; and   a signal transmitted to the controller indicative of the liquid ring pump experiencing a decrease in capacity.   
     
     
         8 . The method of  claim 1 , further comprising venting sealing liquid or compressible fluid from the liquid pump to achieve the predetermined vacuum pressure based on the monitored vacuum pressure. 
     
     
         9 . A method of controlling a liquid ring pump in a pump system, the liquid ring pump driven by a motor controlled by a controller, the method comprising:
 monitoring a parameter in the liquid ring pump using a transmitter configured to transmit a signal indicative of the monitored parameter to the controller in operative communication with the liquid ring pump;   comparing the signal with a predetermined threshold in the controller; and   disabling a motor start function of the motor in response to the signal indicating that the monitored parameter exceeds the predetermined threshold.   
     
     
         10 . The method of  claim 9 , wherein monitoring the parameter includes monitoring a sealing liquid level in the liquid ring pump using a liquid level transmitter configured to transmit a sealing liquid level signal to the controller, and wherein the motor start function is disabled in response to the sealing liquid level signal exceeding a predetermined sealing liquid level threshold. 
     
     
         11 . The method of  claim 10 , wherein the predetermined sealing liquid level threshold includes an upper limit and a lower limit, and wherein the step of disabling the motor start function occurs in response to the sealing liquid level signal indicating that the sealing liquid level is above the upper limit or below the lower limit. 
     
     
         12 . The method of  claim 9 , wherein monitoring the parameter includes monitoring a backpressure of the liquid ring pump with a pressure transmitter and transmitting a signal indicative of the backpressure to the controller, and wherein the motor start function is disabled in response to the backpressure signal indicating that the backpressure exceeds a predetermined backpressure threshold. 
     
     
         13 . A pump system comprising:
 a liquid ring pump configured to compress a fluid;   a variable speed motor operatively coupled to the liquid ring pump to drive the liquid ring pump under variable vacuum flow demand within the pump system;   a transmitter coupled to the pump system and configured to monitor a parameter of the pump system and to transmit a signal indicative of the monitored parameter; and   a controller in communication with the transmitter and the motor, the controller programmed to perform instructions to operatively control the liquid ring pump in response to the signal from the transmitter indicative of the monitored parameter.   
     
     
         14 . The pump system of  claim 13 , wherein the transmitter includes a vacuum pressure transmitter configured to monitor a vacuum pressure of the liquid ring pump, wherein the pressure transmitter is configured to transmit a vacuum pressure signal to the controller, wherein the parameter includes a parameter of the liquid ring pump, and wherein the controller is programmed to maintain a predetermined vacuum pressure in the liquid ring pump under variable vacuum flow demand in response to the vacuum pressure signal by controlling the pump parameter based on a comparison of the vacuum pressure signal to the predetermined vacuum pressure by the controller. 
     
     
         15 . The pump system of  claim 14 , wherein the controller is programmed to vary a speed of the motor to maintain the predetermined vacuum pressure based on a comparison of the vacuum pressure signal to the predetermined vacuum pressure by the controller. 
     
     
         16 . The pump system of  claim 15 , wherein the controller is programmed to:
 determine a rotational speed of the motor associated with maintaining the predetermined vacuum pressure based on the monitored vacuum pressure, and   adjust the rotational speed of the motor to match the determined rotational speed.   
     
     
         17 . The pump system of  claim 14 , wherein the controller is programmed to modulate a flow rate of sealing liquid into the liquid ring pump in response to the signal indicative of the monitored vacuum pressure. 
     
     
         18 . The pump system of  claim 13 , wherein the parameter includes a parameter of the liquid ring pump, and wherein the controller is programmed to disable a motor start function of the motor in response to the signal indicating that the monitored parameter exceeds a predetermined threshold. 
     
     
         19 . The pump system of  claim 18 , wherein the pump parameter includes a sealing liquid level in the liquid ring pump measured by the transmitter configured to transmit a sealing liquid level signal to the controller, and wherein the controller is programmed to disable the motor start function in response to the sealing liquid level signal exceeding a predetermined sealing liquid level threshold. 
     
     
         20 . The pump system of  claim 18 , wherein the pump parameter includes a backpressure in the liquid ring pump measured by the transmitter configured to transmit a backpressure signal to the controller, and wherein the controller is programmed to disable the motor start function in response to the backpressure signal exceeding a predetermined backpressure threshold.