Patent ID: 11940178
Assignee: DRI-STEEM CORPORATION
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 5:
6. A gas-fired humidifier comprising:
a) an atmospheric pressure storage tank for holding a volume of water, the storage tank having a make-up water inlet and a steam outlet;
b) a gas-fired burner and combustion blower assembly;
c) a primary heat exchanger connected to the gas-fired burner and combustion blower assembly, the primary heat exchanger being located within the storage tank and configured to heat the volume of water to generate steam;
d) a make-up water heat exchanger configured to receive exhaust gases generated and discharged by the gas-fired burner and combustion blower assembly to pre-heat make-up water delivered to the storage tank, the make-up water heat exchanger having a combustion gas side through which exhaust gases flow in an upward direction, and a water side in which the make-up water flows in a downward direction;
e) a first conduit connecting a first port of the make-up water heat exchanger to the storage tank make-up water inlet;
f) a second conduit connecting an exhaust gas inlet port of the make-up water heat exchanger to an outlet of the primary heat exchanger;
g) a make-up water valve assembly, including a solenoid valve and a pressure compensating orifice downstream of the solenoid valve, for controlling a net flow rate of an inlet water stream into the make-up water heat exchanger, the make-up water valve assembly being directly connected to the make-up water heat exchanger by a third conduit; and
h) an electronic controller configured to send a pulse-width-modulated output signal to the make-up water valve assembly to supply make-up water to the make-up water heat exchanger;
i) a pressure equalization line connecting a second port of the make-up water heat exchanger to the storage tank at a location above the make-up water inlet, the second conduit including a trap section to block steam from the storage tank from entering the make-up water heat exchanger.