Electric steam generating device

Abstract

An electric steam generating device includes a cast body, a heating element, and a fluid passage. The heating element is at least partially surrounded by the cast body. The fluid passage passes through the cast body and is spaced apart from the heating element. The cast body transfers heat from the heating element to the fluid passage, and the fluid passage includes a first portion having a first size and a second portion having a second size.

What is claimed is: 
     
         1 . An electric steam generating device comprising:
 a cast body;   a heating element at least partially surrounded by the cast body; and   a fluid passage through the cast body and spaced apart from the heating element, wherein the cast body transfers heat from the heating element to the fluid passage,   wherein the fluid passage includes a first portion having a first size and a second portion having a second size.   
     
     
         2 . The electric steam generating device of  claim 1 , further comprising:
 a passage adapter coupled to the first portion of the fluid passage and the second portion of the fluid passage.   
     
     
         3 . The electric steam generating device of  claim 1 , wherein the first size of the first portion has a small diameter or small cross sectional flow area, and the second size of the second portion has a large diameter or a large cross sectional flow area. 
     
     
         4 . The electric steam generating device of  claim 1 , wherein the first size of the first portion has small width, and the second size of the second portion has a large width. 
     
     
         5 . The electric steam generating device of  claim 1 , wherein:
 the first portion has circular cross section, and the second portion has a rounded rectangular cross section; or   the first portion has a rounded rectangular cross section, and the second portion has a circular cross section.   
     
     
         6 . The electric steam generating device of  claim 1 , further comprising:
 a supply valve; and   a flow sensor configured to measure of flow of fluid into the fluid passage, wherein the supply valve is operated in response to the measured flow of fluid.   
     
     
         7 . The electric steam generating device of  claim 1 , further comprising:
 a flushing valve, wherein the flushing valve is operated according to a flush cycle.   
     
     
         8 . The electric steam generating device of  claim 7 , wherein the flush cycle occurs at a predetermined time with respect to a time of day or a time of a steam cycle. 
     
     
         9 . The electric steam generating device of  claim 7 , wherein the flush cycle removes scale, minerals, or debris from the fluid passage. 
     
     
         10 . A control system for a steam generator, the control system comprising:
 a metering loop coupled to a water inlet and the steam generator;   a flush loop coupled to the water inlet and the steam generator;   a first valve between the water inlet and the steam generator on the metering loop;   a second valve between the water inlet and the steam generator on the flush loop; and   a controller configured to open the first valve during a steam cycle and configured to close the first valve and open the second valve during a flush cycle after the steam cycle.   
     
     
         11 . The control system of  claim 10 , further comprising:
 a flow meter associated with the metering loop and configured to measure a flow of water through the metering loop.   
     
     
         12 . The control system of  claim 11 , wherein the controller is configured to activate a flush cycle based on the flow of water through the metering loop indicating blockage or buildup in the steam generator. 
     
     
         13 . The control system of  claim 11 , wherein the controller is configured to control the first valve in response to the measured flow of water. 
     
     
         14 . The control system of  claim 10 , further comprising:
 a temperature sensor associated with the steam generator and configured to measure a temperature of the steam generator.   
     
     
         15 . The control system of  claim 14 , further comprising:
 a heating element, wherein the controller is configured to operate the heating element in response to the measured temperature.   
     
     
         16 . The control system of  claim 10 , further comprising:
 a timer configured to measure operation time of the steam generator or the metering loop supplying the steam generator, wherein the controller is configured to operate the first valve and the second valve in response to the operation time.   
     
     
         17 . The control system of  claim 10 , wherein the controller is configured to activate a flush cycle of the flush loop by opening the second valve. 
     
     
         18 . The control system of  claim 10 , wherein a flow of water through the flush loop has a greater flow rate than a flow of water through the metering loop. 
     
     
         19 . A method for operation of a steam generator, the method comprising:
 connecting a heating element of the steam generator to a power source;   opening a first valve between a water inlet and the steam generator on a metering loop during a steam cycle;   closing the first valve; and   opening a second valve between the water inlet and the steam generator on a flush loop coupled to the water inlet and the steam generator during a flush cycle.   
     
     
         20 . The method of  claim 19 , further comprising:
 receiving sensor data for the steam generator or the metering loop, wherein the steam cycle is started, the flush cycle is started, or the heating element is disconnected in response to the sensor data.