System and Method for Refilling an Electrolyzer Tank from a Water Reservoir

Abstract

A system for controlling electrolyte level and concentration within a water electrolyzer includes an electrolysis chamber containing electrolyte for production of hydrogen and oxygen, a water reservoir containing make-up water and separated from the electrolysis chamber through a check valve that opens only when electrolyte level drops to a predetermined level, and a gas lift pump within the water reservoir connected to the electrolysis chamber through the check valve and having electrodes immersed in the make-up water. Energization of the electrodes creates bubbles that transport the make-up water to the electrolysis chamber to maintain a desired concentration of the electrolyte during the production of hydrogen and oxygen.

1 . A water electrolyzer comprising:
 an electrolysis chamber for production of hydrogen and oxygen; and   a water reservoir from which make-up water is transported to the electrolysis chamber to maintain a constant hydrogen output.   
     
     
         2 . The water electrolyzer of  claim 1  further comprising a gas lift pump transporting the make-up water from the water reservoir to the electrolysis chamber. 
     
     
         3 . The water electrolyzer of  claim 2  wherein activating gas in the gas lift pump is supplied via electrolysis of the make-up water. 
     
     
         4 . The water electrolyzer of  claim 3  further comprising a primary chamber in the gas lift pump and a pump lift tube adjacent to the primary chamber, the primary chamber configured to accumulate bubbles from the electrolysis of the make-up water and to promote formation of an aggregate bubble and release of the aggregate bubble into the pump lift tube to force make-up water to a higher level. 
     
     
         5 . The water electrolyzer of  claim 2  further comprising the gas lift pump fitted with a check valve that allows flow of the make-up water into the electrolysis chamber only when electrolyte level within the electrolysis chamber drops below a predetermined minimum level. 
     
     
         6 . The water electrolyzer of  claim 4  further comprising the gas lift pump having an overflow opening allowing gas to escape from the pump lift tube and allowing excess make-up water to spill back into the water reservoir when the check valve is closed. 
     
     
         7 . A water electrolyzer comprising:
 an electrolysis chamber containing electrolyte for production of hydrogen and oxygen;   a water reservoir containing make-up water;   a check valve separating the electrolysis chamber from the water reservoir; and   a gas lift pump within the water reservoir, the gas lift pump in fluid communication with the electrolysis chamber through the check valve and having electrodes immersed in the make-up water;   whereby energization of the electrodes transports the make-up water to the electrolysis chamber to maintain a desired concentration of the electrolyte during the production of hydrogen and oxygen.   
     
     
         8 . The water electrolyzer of  claim 7  wherein the check valve comprises a float ball at least partially immersed in the electrolyte. 
     
     
         9 . The water electrolyzer of  claim 7  wherein the electrodes and the electrolysis chamber are energized by a common power supply. 
     
     
         10 . The water electrolyzer of  claim 7  wherein the electrodes are energized by an independent power supply. 
     
     
         11 . The water electrolyzer of  claim 7  wherein the inner wall includes a gas pressure equalization port between the electrolysis chamber and the water reservoir. 
     
     
         12 . The water electrolyzer of  claim 7  further comprising a primary chamber in the gas lift pump and a pump lift tube adjacent to the primary chamber, the primary chamber configured to accumulate bubbles from electrolysis of the make-up water and to promote formation of an aggregate bubble and release of the larger bubble into the pump lift tube to force make-up water toward the check valve. 
     
     
         13 . The water electrolyzer of  claim 7  further comprising the gas lift pump having an overflow opening allowing gas to escape from the pump lift tube and allowing excess make-up water to spill back into the water reservoir. 
     
     
         14 . The water electrolyzer of  claim 13  wherein the overflow opening has a diameter greater than a diameter of the pump lift tube to promote escape of the aggregate bubble. 
     
     
         15 . The water electrolyzer of  claim 13  wherein the overflow opening comprises an edge for dividing the aggregate bubble to promote escape of gasses from the pump lift tube. 
     
     
         16 . The water electrolyzer of  claim 12  wherein the gas lift pump comprises a shroud surrounding the electrodes. 
     
     
         17 . The water electrolyzer of  claim 16  wherein a portion of the gas lift tube extends into the shroud to form the primary chamber. 
     
     
         18 . A method for maintaining concentration of an electrolyte in a water electrolyzer during electrolysis of water, comprising:
 containing the electrolyte within an electrolysis chamber;   providing a water reservoir containing make-up water;   connecting the make-up water to the electrolyte through a check valve that opens only when the electrolyte in the electrolysis chamber drops below a predetermined level;   immersing a gas lift pump within the water reservoir, the gas lift pump in fluid communication with the electrolysis chamber through the check valve; and   energizing the gas lift pump to transport the make-up water to the electrolysis chamber.   
     
     
         19 . The method of  claim 18  wherein the energizing step comprises applying electrical energy to electrodes within the gas lift pump to produce bubbles that force the make-up water toward the check valve. 
     
     
         20 . The method of  claim 19  further comprising energizing the electrodes and the electrolysis chamber from a common power supply.