Steam generator
A steam generator includes an inlet configured to receive a liquid (such as water); a heating element for converting the liquid into a vapor (such as steam), the vapor bearing particles such as mineral deposits formed by the converting of the liquid; an outlet in fluid communication with the inlet, the outlet configured to discharge filtered vapor and having a size on the order of larger ones of the particles; and a filter structure adjacent to the outlet to filter the larger particles out of the vapor to produce the filtered vapor for discharge from the outlet. By action of the filter structure, larger particles are prevented from reaching the outlet, reducing clogging and extending the usable lifetime of a small appliance containing the steam generator. The filter structure may include spaced-apart members such as posts or pillars extending perpendicularly in a planar fluid flow passage.
1. A steam generator for a small appliance, comprising:
an inlet configured to receive a liquid;
a heating element for converting the liquid into a vapor, the vapor bearing particles formed by the converting of the liquid;
an outlet in fluid communication with the inlet, the outlet configured to discharge filtered vapor and having a size on the order of larger ones of the particles;
a filter structure to filter the larger particles out of the vapor to produce the filtered vapor for discharge from the outlet, wherein the filter structure comprises an array of spaced pillars forming a screen that is larger than an opening of the outlet;
a planar passage at the outlet;
a planar outer cover comprising a planar top section and a planar bottom section, wherein the outlet is located in the planar top section and the inlet is located in the planar bottom section; and
a planar interior section disposed between the planar top section and the planar bottom section of the planar outer cover and containing the heating element;
wherein interior planar surfaces of the planar outer cover and the planar interior section define at least part of a fluid flow path including the planar passage;
wherein the interior planar surfaces of the planar outer cover and the planar interior section include vanes configured to guide the fluid along the fluid flow path; and
wherein the spaced pillars extend between the interior planar surfaces of the planar outer cover in an orientation orthogonal to the planar surface of the planar outer cover and the planar surface of the planar interior section.
2. The steam generator according to claim 1 , wherein spacing among the spaced pillars includes at least some spacing smaller than the opening of the outlet.
3. The steam generator according to claim 1 , wherein spacing among the spaced pillars is in a range of 1 to 10 millimeters.
4. The steam generator according to claim 1 , wherein the pillars have a polygonal cross section.
5. The steam generator according to claim 4 , wherein the polygonal cross section is a square cross section.
6. The steam generator according to claim 1 , wherein the vanes define points at which a direction of the fluid flow path changes abruptly.
7. The steam generator according to claim 1 , wherein a second cover includes the inlet and defines, along with the planar interior section, another part of the fluid flow path.
8. The steam generator according to claim 1 , wherein the planar outer cover includes the pillars formed integrally therewith.
9. The steam generator according to claim 1 , wherein the planar passage includes a non-integral filter element as part of the filter structure.
10. The steam generator according to claim 1 , further including a thermostat located adjacent to the inlet to sense an operating temperature of the steam generator.
11. The steam generator according to claim 1 , wherein the particles are salts of minerals occurring in cation form in the liquid.
12. The steam generator according to claim 11 , wherein the minerals include calcium and magnesium.