Energy efficient, safe, customizable stovetop system

Abstract

A stovetop system comprising a stovetop, wound around a burner, supports a vessel to be heated. The hot gas from the burner is guided through an extended path under the vessel's bottom to improve the heating efficiency of a stove on which this standalone stovetop system is installed. Improvements in safety, vessel adaptability, and automatic temperature control of the heating process are also achieved.

Claims

1-7. (canceled)

8. An energy-efficient, customizable stovetop system comprising: at least one stovetop (11) wound a plurality of times with continuous space between the windings around a hot gas source to support a vessel substantially aligned with the hot gas source, with its bottom surface in contact with the edge of the windings to create a path bound by the windings on the sides and said vessel's bottom surface on the top for the hot gas to flow thereby increasing the contact time of the hot gas with said vessel manyfold compared to the contact time along a guided or unguided radial path under said vessel thereby increasing the heating efficiency; and an exhaust system (20) comprising an outlet located away from the stovetop surrounding, outside the room of the stovetop, and dispose hot gas from an inlet (21) located at the end of or anywhere in the space between the windings at the periphery of said vessel thereby adapting to the vessel's size, drawing all the hot gas with harmful chemicals away from the stovetop, not heating the stovetop surrounding and preventing the hot gas from coming in contact with flammable fumes from the contents of the vessel that can result in a fire incident.

9. The energy-efficient, customizable stovetop system of claim 8, further comprises risers (16) installed on the stovetop (11) windings biased upward by springs to close gaps between the stovetop (11) windings and the bottom surface of a vessel thereby confining the hot gas in the winding path.

10. An energy-efficient, customizable stovetop system comprising: at least one stovetop (11) wound a plurality of times with continuous space between the windings around a hot gas source to support a vessel substantially aligned with the hot gas source, with its bottom surface in contact with the edge of the windings to create a path bound by the windings on the sides and said vessel's bottom surface on the top for the hot gas to flow thereby increasing the contact time of the hot gas with said vessel manyfold compared to the contact time along a guided or unguided radial path under said vessel thereby increasing the heating efficiency; an exhaust system (20) comprising an outlet located away from the stovetop surrounding, outside the room of the stovetop, and dispose hot gas from an inlet (21) located at the end of or anywhere in the space between the windings at the periphery of said vessel thereby adapting to the vessel's size, drawing all the hot gas with harmful chemicals away from the stovetop, not heating the stovetop surrounding and preventing the hot gas from coming in contact with flammable fumes from the contents of the vessel that can result in a fire incident; and a control system comprising a computer processor with software to control the hot gas temperature at said inlet (21) by operating a valve supplying fuel to said burner based on the input from a temperature sensor located at said input (21) and the operating parameters set in the software program thereby controlling the heating of the vessel.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0029] FIG. 1 shows the elevation views of a gas stove showing the flow path of the hot gas under vessels of prior art.

[0030] FIG. 2 shows a flow path of hot gas under a vessel in prior art.

[0031] FIG. 2A shows other flow paths of hot gas under a vessel in prior art.

[0032] FIG. 3 shows the various possible patterns of windings of stovetops.

[0033] FIG. 4 shows a few examples of the number of windings of stovetops.

[0034] FIG. 5 is an isometric view of one embodiment of the stovetop system.

[0035] FIG. 6 is an isometric view of the exhaust system.

[0036] FIG. 7 is an isometric view of the burner and valve.

[0037] FIG. 8 is an isometric view of one embodiment of the stovetop system and burner system.

[0038] FIG. 9 is an isometric view of the flow path of hot gas under a vessel.

[0039] FIG. 10 is an isometric view of the flow path of hot gas under a plate.

[0040] FIG. 11 is an elevation view of the first embodiment of the stovetop system with a vessel.

[0041] FIG. 12 is a top view of the stovetop system showing the flow path of hot gas.

[0042] FIG. 13 is the profile across the flow path.

[0043] FIG. 14 is a top view of a large vessel and relative orientation of the exhaust inlet.

[0044] FIG. 15 is an isometric view of a large vessel and relative orientation of the exhaust inlet.

[0045] FIG. 16 is a top view of a small vessel and relative orientation of the exhaust inlet.

[0046] FIG. 17 is an isometric view of a small vessel and relative orientation of the exhaust inlet.

[0047] FIG. 16A shows various views of the first embodiment with a large, curved bottom vessel and relative orientation of the exhaust inlet.

[0048] FIG. 16B shows various views of the first embodiment with a small, curved bottom vessel and relative orientation of the exhaust inlet.

[0049] FIG. 18 shows an elevation view of a curved bottomed vessel heated placed over the strip 11.

[0050] FIG. 19 is an isometric view of another embodiment.

[0051] FIG. 20 is an isometric view of another embodiment with a vessel.

[0052] FIG. 21 is an isometric view of the strip 11 with one of the risers 16.

[0053] FIG. 22 is the view through direction A of FIG. 21.

[0054] FIG. 23 is the side view of riser 16.

[0055] FIG. 24 is an elevation view of this embodiment showing the curved bottom vessel 14 mounted on a stovetop system.

[0056] FIG. 25 is the plan view of the stovetop system with risers 16.

[0057] FIG. 26 A section B-B of FIG. 25 is shown in FIG. 20.

[0058] FIG. 27 is the profile across the hot gas path.

[0059] FIG. 28 shows the temperature and chemical control system.

DETAILED DESCRIPTION OF THE INVENTION

[0060] The inventor provides a unique stovetop system for an energy efficient, safe, customizable, standalone operation.

[0061] In one embodiment, a stovetop system 10, shown in FIG. 5, comprises a stovetop 11 that is in the form of a thin strip, made of material capable of withstanding high temperature and load and an exhaust system 20. This strip is wound around a heat source 31, including a gas burner. Sample winding patterns are shown in FIG. 3 and FIGS. 4A through 4G with space between each winding. The exhaust system 20 comprises an inlet 21 and an outlet 23 connected by a conduit 22.

[0062] A vessel 12 to be heated is supported by stovetop 11. The upper edge of the stovetop 11 matches the bottom shape of a vessel 12. In this embodiment the bottom surface of the vessel 12 is flat and circular.

[0063] The stovetop 11 is installed over and around a burner 31 by supporting means including legs attached to the stovetop 11. This standalone stovetop 11 can be adapted to be installed over a gas stove 30 with a burner 31 connected to a gas valve 32 in series with an electronic control valve 33 shown in FIG. 7. The centers of stovetop 11, the vessel 12, and the burner 31 are substantially aligned.

[0064] The stovetop 11 has a one single continuous path beginning from the burner and ends at outer most winding. The single port exit helps processing of all the exiting hot gas from the stovetop 11. The hot gas from the burner 31 moves through the space between the windings of stovetop 11 under the vessel 12 and exits the stovetop 11 through the inlet 21 of the exhaust system 20. The outlet 23 is located optimally in a place so that free flow of the hot gas is established. The inlet 21 is at a negative pressure by natural draft through the exhaust system due to the location of the outlet 23. In the event the negative pressure is insufficient a draft fan 24, shown in FIG. 6, is installed in the exhaust system downstream of the inlet 21. The inlet 21 is inserted in the space between the winding or at the end of the winding is tightly held. The inlet 21 is inserted in the space through which the hot gas passes within the stovetop 11 or at the end of the winding. The stovetop 11 can be encased in a casing, not shown in figures, into which the inlet 21 can be inserted. All the hot gas passing through the space between the windings and under the vessel exits only through the inlet 21 followed by the conduit 22 and outlet 23 and not into the surrounding of the stove on which the stovetop 11 is installed.

[0065] Heat transfer efficiency is one of the improvements of this embodiment. The hot gas from the burner moves under the vessel through a path created by the space between the windings as shown in FIG. 9 and FIG. 10. FIG. 9 is an isometric view of the stovetop system with vessel 12, shown translucently, placed over the stovetop 11 and the hot gas path is shown by arrows. FIG. 10 is an isometric view of a stovetop system with a plate, shown translucently, and the path of the hot gas by arrows. FIG. 11 is an elevation view of the stovetop system showing a flat-bottomed vessel 12 placed over the stovetop 11 with a gas burner 31 in its center zone. The hot gas exits at the inlet 21 of the exhaust system 20.

[0066] FIG. 12 is a top view of the stovetop system. The hot gas path, shown by arrows, is many times longer than the radial path R, the distance from the center of the source to the edge of the vessel under the vessel.

[0067] A section A-A cut in the plan view in FIG. 12 is shown in FIG. 13. The profile across the hot gas path, as shown in FIG. 13, is confined on the sides by the adjacent windings W and WA and the vessel's bottom surface 13 on top. The gap between the stovetop 11 windings W and WA and the bottom surface 13 of the vessel 12 is kept negligibly small for efficient functioning so that hot gas does not flow through any gap directly into adjacent winding instead of moving around through the path.

[0068] Since the hot gas is lighter than colder air the hot gas moves up and is in contact with the bottom surface 13 of the vessel 12. The height of the profile is tall enough such that the hot air does not flow downwards and into adjacent winding or exit the stovetop 11 through the bottom.

[0069] This winding path being longer than the radial path R, increases the contact time between the hot gas and the vessel thereby increasing the heat transfer between the hot gas and the vessel resulting in a higher heating efficiency. Heating efficiency can be defined as the ratio of energy Qa, the energy absorbed by the vessel to the energy content of the hot gas Qi from the burner during the time of the heating. n=Qa/Qi. The longer the hot gas path, the higher the time of contact between the hot gas and the vessel and the higher the heating efficiency. After a steady state is reached in the heating process the heating efficiency drops significantly since the vessel absorbs little energy as the vessel temperature remains steady and the fuel flow to the burner 31 is reduced to a minimum just enough to make up for the heat loss or temperature drop of the vessel due to thermal radiation.

[0070] FIG. 4A shows a winding path under a heated vessel with a circular bottom with radius R. The length of the winding path along the boundary shown is three times longer than R. It is safe to say that the contact time between any unit volume of the hot gas and the vessel's bottom is three times than the contact time through the direct path along R making this flow path three times heat efficient. Winding paths shown in FIGS. 4B through 4G show paths with an increasing number of windings. The increase in energy efficiency of paths shown in FIGS. 4B, 4C, 4D, 4E, 4F, and 4G are 8, 11, 14,17, 21, 25, and 28 times longer than the radial path R respectively. It can be safely estimated that the heating efficiency increment is also in the same multiple.

[0071] The heat transfer efficiency is affected by many factors such as the temperature difference between the hot gas and the vessel, specific heat of the vessel, fuel flow rate into the burner that affects the hot gas flow rate, and the time of contact between the hot gas and the vessel. This embodiment can customize the time of contact for improved heating efficiency by the inserting location of the inlet 21.

[0072] Vessel adaptability is one of the improvements of this embodiment. FIGS. 14 through 16 show the vessel size and inlet 21 orientation inside the stovetop 11. FIG. 14 is the plan view of the stovetop system on which a large vessel 12L is placed. The inlet 21 of the exhaust system is inserted into the stovetop 11 at a location LL near the edge of the bottom of the vessel 12L to maximize the contact time. For a smaller vessel 12S the inlet 21 needs to be moved towards its edge so that the inlet is completely within the boundary of the smaller vessel 12S.

[0073] If the inlet 21 is located partially outside the bottom of the vessel the suction at the inlet is diluted with surrounding air which may affect the hot gas flow rate. If the inlet is fully outside the bottom of the vessel the heating efficiency is low and undeterminable and the hot gas escapes into the stovetop surrounding that might cause health and fire hazards. The inlet 21 of the exhaust system is inserted into the stovetop under the vessel in a location that is close to the edge of vessel's bottom for achieving the best heating efficiency and preventing hot gas escape into the kitchen.

[0074] Kitchen heat reduction is one of the improvements of this embodiment. If the kitchen is cooled by air conditioning letting the hot air escape into the kitchen will heat up the kitchen and result in higher cooling cost. This embodiment disposes the hot gas from the stovetop 11 outside of the kitchen through the outlet 23 of exhaust system 20.

[0075] Health risk prevention is one of the improvements of this embodiment. The hot gas from the stove is disposed outside of kitchen preventing the harmful chemicals and particles from human inhalation.

[0076] Spill over and grease fire prevention is another improvement of this embodiment. If the contents of the vessel spill over or boil over the overflow liquid can reach the burner and extinguish the flame resulting in the release of raw fuel into the surrounding causing fire and health hazards. The stovetop in this embodiment prevents the overflow of the vessel contents from reaching the burner since the bottom of the vessel is contact with the upper edge of the stovetop 11 stops the flow of overflow contents of the vessel under the vessel thereby eliminating a fire incident.

[0077] If the flames from the burner encounter any flammable fumes from the hot contents in the vessel fire can occur. In this embodiment the cooking fumes do not come in direct contact with the hot gas from the burner 31 exits through the inlet 21. The end of the winding can be modified to extend away from the vessel.

[0078] Vessel adaptability is another improvement resulting in this invention. FIG. 16A shows elevation, top and isometric views of a stovetop system with stovetop 11S on which a vessel 14SL with curved bottom is placed. The upper edge of the stovetop 11S matches the bottom shape of the vessel 14SL to ensure the profile across the hot gas path is without gaps at the junction of the windings and the bottom surface of the vessel 14SL. The inlet 21 is located at the edge of the vessel 12SL to take in hot gas from the stovetop 11S. FIG. 16B shows the elevation, top and isometric views of a stovetop system with stovetop 11S on which a vessel 14SS with curved bottom is placed. Vessel 14SS is smaller than vessel 14SL but has the same bottom shape of 14SL. When the smaller vessel 14SS is placed over stovetop 11S the inlet 21 is moved towards the center at its edge. This establishes the vessel adaptability feature of this embodiment.

[0079] Another embodiment of stovetop system 10 is a further improvement of the one embodiment described.

[0080] FIGS. 18, 19, 20, 21, 22, and 23 are referred to in the description of this embodiment. A vessel 14 with a curved bottom is used in this embodiment. FIG. 18 shows an elevation view of a curved bottomed vessel placed over the stovetop 11 with its upper edges flat. The curved bottom of the vessel is in contact only with a small section of the windings of the stovetop 11 with a flat upper edge profile. Hence the extended path created by a flat bottomed vessel over the stovetop 11 as shown in FIG. 12 is not created with a curved bottomed vessel. The hot gas does not flow through the space between the windings. Hot gas escaping through the gap between the top edge of the stovetop 11 and the curved bottomed vessel is shown by the arrows in FIG. 18.

[0081] To prevent the escape of the hot gas through the gap a plurality of closely packed risers 16 are installed over the top of the stovetop 11 as shown in FIG. 19. The risers 16 move up and contact the curved bottom vessel 14 as shown in FIG. 24. All the risers 16 move up and literally seem to extend the upper edge of the stovetop 11 to conform to the shape of the vessel's bottom.

[0082] A riser 16 is a casing wrapped around a small section the stovetop 11. FIG. 21 is an isometric view of the stovetop 11 with one of the risers 16. FIG. 22 is the view through direction A of FIG. 21 and FIG. 23 is the side view of riser 16 showing the riser 16 lifted by a spring 17 that rests on the stovetop 11. At the top of the riser 16 is a soft pad to close any gap between the contact surface of the vessel and the riser 16 to prevent hot gas passing across the top of the riser 16. A pin 18 across the riser 16 below the stovetop 11 holds the riser in place. Without this pin the riser 16 will pop out of the stovetop 11 due to the force of the spring 17. As an alternative means, the riser 16 can be folded under the stovetop 11 to prevent the popping out of the stovetop 11. Each riser 16 is shaped to move freely on the section of the stovetop 11 it is installed and to withstand the forces exerted by the vessel and its contents. The risers guide the hot gas along the space between the windings.

[0083] FIG. 24 is an elevation view of this embodiment showing a curved bottom vessel 14 mounted on a stovetop system with a stovetop. FIG. 25 is the plan view of the stovetop system with risers 16. As shown in FIG. 20 a section B-B of FIG. 19 the risers at the outer windings have moved up to engage with the bottom surface 15 of the curved bottomed vessel 14 there by creating a profile of the path covered on the sides by the risers of consecutive windings and on the top by the bottom surface 15 of the curved bottom vessel 14. The profile across the hot gas path is shown in Detail C in FIG. 27. The profile boundaries are the risers 16 on the sides and the bottom surface 15 of the vessel 14 on the top. The bottom of the profile is left open for combustion air to enter. The height of the profile is designed such that the hot gas does not come out of the profile through the bottom creating a heat efficiency reduction. All the improvements of the previously described embodiment are applicable to this embodiment while the uniqueness of this embodiment is that it can support vessels of various shapes and sizes while maintaining increased heating efficiency. The vessel adaptability of the first embodiment is shown in FIG. 16A and FIG. 16B are also applicable to this embodiment. But FIG. 16A and FIG. 16B do not show the risers.

[0084] Temperature and chemical control are added to the embodiments as an improvement. The schematic diagram in FIG. 28 shows the temperature and chemical control system. This system comprises a controller 34 that receives input data regarding temperature from various locations including the exhaust system, vessel, and strip, chemical concentration sensing system 51 to sense the presence of harmful chemicals, control software to operate draft fan 24 and electric fuel flow control valve 33 based on operating parameters, user input parameters, and temperature and chemical threshold.

[0085] The user can set temperature parameters for the heating process including the temperature of the hot gas at the stovetop, exhaust system, vessel, and vessel contents. The controller operates the electric fuel flow control valve 33 and draft fan 24 to operate per user set parameters and a control software program in the memory storage of the controller. The electric fuel flow control valve 33 is closed in case a threshold temperature is exceeded in the system to prevent uncontrolled fire due to system malfunction.

[0086] A chemical control system detects hazardous chemicals in the hot gas or leaking fuel through a closed fuel control valve. The hot gas passing through the exhaust system 20 is routed through chemical reaction chambers including catalytic converters, not shown in figure, to reduce or eliminate hazardous chemical release.

[0087] Temperature and chemical quantity threshold are set to control fire hazard or chemical hazard events by activating control draft fan and shutting off electric fuel flow control valve 33.