Self-powered pump for heated liquid, fluid heating and storage tank and fluid heating system employing same

A fluid heating system comprising:

• a fluid heating and storage tank comprising:
• a storage tank for a primary fluid, said storage tank having a primary fluid inlet, a primary fluid outlet, a secondary fluid inlet and a secondary fluid outlet;
• and
• apparatus disposed within said storage tank for flowing a secondary fluid which is a liquid through said storage tank in isolation from said primary fluid, said apparatus fluidly interconnecting said secondary fluid inlet with said secondary fluid outlet and comprising a heat exchanger;
• a heater for the secondary fluid, said heater having an inlet and an outlet for secondary fluid, said outlet being higher than said fluid heating and storage tank;
• a return conduit for flowing secondary fluid from said secondary fluid outlet of said fluid heating and storage tank to said heater inlet;
• a self-powered pump for the secondary fluid which is a liquid, said pump being above a level of said heater outlet, said pump comprising:
• an airtight container for containing the secondary fluid, said airtight container having a base and a top;
• a secondary fluid inlet pipe extending upwardly into said airtight container such that a first end of said inlet pipe is within the airtight container;
• a secondary fluid outlet pipe extended out from said airtight container, wherein a second end of said secondary outlet pipe is within said airtight container and lower than said first end of said inlet pipe;
• a breathing pipe extending upwardly into said airtight container such that an upper end of said breathing pipe is within the airtight container and is higher than said first end of said inlet pipe and said second end of said outlet but lower than said top of said airtight container, an opposite end of said breathing pipe being outside said airtight container and lower than said base;
• and
• an open container open to the atmosphere for receiving said opposite end of said breathing pipe wherein said breathing pipe allows bi-directional fluid flow between said airtight container and said open container when said heated liquid overflows from said airtight container to said open container;
• a conduit for flowing secondary fluid upwardly from said heater outlet to said secondary fluid inlet pipe of said self-powered pump;
• and
• a conduit for flowing secondary fluid from said self-powered pump outlet to said secondary fluid inlet of said fluid heating and storage tank.

A liquid heating system comprising:

• a heater for heating said liquid, said heater having an inlet for the liquid and an outlet for the liquid;
• a self-powered pump for pumping the heated liquid, said pump being above a level of said heater outlet, said pump comprising:
• an airtight container for containing the heated liquid, said airtight container having a base and a top;
• a heated liquid inlet pipe extending upwardly into said airtight container such that a first end of said inlet pipe is within the airtight container;
• a heated liquid outlet pipe extended out from said airtight container, wherein a second end of the heated liquid outlet is within said airtight container and lower than said first end of said inlet pipe;
• a breathing pipe extending upwardly into said airtight container such that an upper end of said breathing pipe is within the airtight container and is higher than both of said first end of said inlet pipe and said second end of said outlet pipe but lower than said top of said airtight container, an opposite end of said breathing pipe being outside said airtight container and lower than said base;
• and
• an open container open to the atmosphere for receiving said opposite end of said breathing pipe, wherein said breathing pipe allows bi-directional fluid flow between said airtight container and said open container when said heated liquid overflows from said airtight container to said open container;
• and
• a conduit for flowing heated liquid upwardly from said heater outlet to said heated liquid inlet pipe of said self-powered pump.