GB2414925A

GB2414925A - A food steamer

Info

Publication number: GB2414925A
Application number: GB0412880A
Authority: GB
Inventors: Chu Ming Tak
Original assignee: Tunbow Electrical Ltd
Current assignee: Tunbow Electrical Ltd
Priority date: 2004-06-09
Filing date: 2004-06-09
Publication date: 2005-12-14
Also published as: GB0412880D0

Abstract

The invention relates to a food steamer comprising a substantially closed vessel having a base 12 and a lid 22, the base including a steam generator 32, 34 having a low level outlet 50 to permit steam to escape into the vessel in a lower region and a high level outlet to permit steam to escape into the vessel in an upper region, wherein the high level outlet is connected to the steam generator by a substantially upright duct 30 having an imperforate wall. A food steamer so arranged is capable of more even distribution of steam than prior food steamers, which results in cooking of food more evenly. In use, the steam can pass from the steam generator into the vessel via the lower and upper outlets. The duct permits steam to exit only at an upper region of the vessel. The vessel may comprise a plurality of food containers 14, 16, 18 stacked on the base.

Description

A Food Steamer The present invention relates to a food steamer.

It is known to provide a food steamer for cooking food. Such a food steamer generally comprises a vessel for food and a steam generator to cook the food. The compartment may have multiple levels for placement of different types of food therein. A particular problem with food steamers with such multiple levels is that the food placed in the lower level compartment either blocks or inhibits the flow of steam beyond such lower level compartment, such that the food contained within the middle or higher level compartments either remains uncooked, or is cooked at a significantly slower place than the food in the lower level compartment.

An example of the prior art that has attempted to overcome such problems is to provide a means of distributing steam in the vessel. However such means have not proved wholly successful because steam is directed to all levels of the vessel, and the amount of steam reaching food at the higher levels is inadequate. An uneven distribution of the steam tends to occur and consequently there is uneven cooking of the food at the various levels.

What is required is an improved food steamer which provides a more advantageous distribution of steam such that food is cooked more evenly.

According to the invention there is provided a food steamer comprising a substantially closed vessel having a base and a lid, the base including a steam generator having a low level outlet to permit steam to escape into the vessel in a lower region and a high level outlet to permit steam to escape into the vessel in an upper region, wherein the high level outlet is connected to the steam generator by a substantially upright duct having an imperforate wall.

In a preferred embodiment the high level outlet is defined by the upright duct.

A food steamer so arranged is capable of more even distribution of steam than the prior food steamer, which results in cooking of food more evenly. In use, the steam can pass from the steam generator into the vessel via the lower and upper outlets. The duct permits steam to exit only at an upper region of the vessel.

In a preferred embodiment the vessel includes a plurality of food containers stackable one above another on the base and in the preferred embodiment the containers are close fitting, each container having a floor with holes to allow passage of steam therethrough.

The uppermost container floor has holes positioned such that the part of the floor immediately above the outlet of the duct is imperforate, forcing the flow of steam in a sideways direction.

A food steamer so arranged permits steam to pass from the steam generator into the upper containers via the duct. Steam is released from the duct at the higher region of an upper container from where it can flow throughout the upper container, and from the upper container to the uppermost container directly above via the holes in the floor of the uppermost container. Furthermore steam may also pass upwardly from below through the holes in the floor of each successive container.

Preferably the containers have an imperforate peripheral wall and in a preferred embodiment the outer wall of each container comprises a portion of the outer wall of the food steamer.

Preferably the containers are annular, the duct being disposed through the containers.

Preferably the duct is close fitting with the containers.

The duct may be mounted on the floor of the lowermost container and in a preferred embodiment the floor of the lowermost container has a perforated boss, the duct being mounted on said boss.

Preferably the food steamer further includes a crown container adapted to be stacked on the uppermost container and underneath said lid, the high level outlet being adjacent the underside of said crown container.

Such a crown container can be used to cook food placed therein.

Preferably the crown container is close fitting with the vessel, and the floor of the crown container has holes to allow passage of steam therethrough, in use.

Preferably the food steamer further includes an auxiliary container wherein the auxiliary container is stackable on and/or in the crown container and beneath the lid. Such an auxiliary container may be useful for cooking food such as rice.

In a preferred embodiment the floor of each container is removable. Such an arrangement permits disassembly for cleaning of the containers and also permits large volumes of food to be placed in the vessel.

Preferably the duct has a circular section and in a preferred embodiment the duct comprises a tube of constant section and has orthogonal ends.

Preferably the steam generator is a flash boiler.

The steam generator may include a water tank and an electric heater. Preferably the electric heater is located beneath the water tank. Such an arrangement permits a gravity feed of water to the electric heater.

Preferably the steamer has an external aperture to permit filling thereof.

In a preferred embodiment the electric heater includes a water duct having a heating element adjacent thereto.

Preferably the water duct includes an upright steam aperture for exit of steam therefrom.

In a preferred embodiment a condensate key is provided above the steam generator.

Such a condensate tray is a useful feature to catch condensed water from operation of the steamer. Preferably the condensate tray is annular and defines a serpentine channel to the low level aperture.

The food steamer may be provided with controller for controlling the operation of the steam generator. In a preferred embodiment the food steamer is provided with a liquid crystal display.

Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings, in which; - Figure 1 is a diagrammatic cross section of a food steamer according to the present Invention.

- Figure 2 is an exploded perspective representation of the food steamer of Figure 1.

- Figure 3 is diagrammatic cross section of the food steamer of Figure 1 illustrating steam circulation.

Referring firstly to Figure 1 there is shown a diagrammatic cross section of a food steamer according to the present invention, generally designated 10. The food steamer 10 comprises a base 12 having steam baskets 11 stacked thereon. In use the baskets 11 comprise a lower steam basket 14, a middle steam basket 16, an upper steam basket 18, and a rice basket 20, the rice basket 20 being above the upper steam basket 18. The top of the food steamer 10 has a lid 22. Each of the lower steam basket 14, the middle steam basket 16 and the upper steam basket 18 are provided with a respective removable floor 24, 26, 28.

Also shown in Figure 1 is a duct 30 at the centre of the steamer 10 to guide steam from the base 12 to the baskets 11. The duct 30 is mounted on the removable floor 24 of the lower steam basket 14, and passes through the removable floor 26 of the middle steam basket 16. The free end of the duct 30 opens adjacent the underside of the removable floor 28 of the upper steam basket 18. The base 12 has a water tank 32 having compartments 34 which can be filled with water via an aperture 36. The base 12 has a water heater 38 for producing steam which exits through a steam cap 40. A drip tray 42 is provided between the baskets 11 and the base 12 for catching water due to condensation. The heater 38 comprises a water channel 44 with a heating element 46 directly above. The baskets and duct are preferably of metal.

Now turning to Figure 2 there is shown an exploded perspective representation of the food steamer 10 of Figure 1. Like features are shown with like reference numerals. In Figure 2 the removable floors 24, 26, 28 are provided with perforations to permit steam to pass therethrough. The removable floor 24 of the lower steam basket 14 has a perforated boss 25 on which the duct 30 is seated. The peripheral wall of the baskets 11 are imperforate. The base 12 has a liquid crystal display 48 and controller (not shown) for controlling the operation of the heating element. Figure 2 also shows that the baskets 11 are generally circular in section.

Figure 2 further shows that each of the baskets 11 and the drip tray 42 have respective oppositely opposed handles 15, 17, 19, 21, 43 at the side thereof. The lid 22 is also provided with a common handle 23. In use the handles 15, 17, 19, 21, 23, 43 permit ready stacking and destacking of the drip tray 42, baskets 11 and lid 22. Each of the baskets 11 and drip tray 42 has a respective annular shoulder 60, 62, 64, 66, 68 to further assist in stacking. The respective shoulders 60, 62, 64 of the lower basket 14, the middle basket 16 and the upper basket 18 are at a lower region thereof. The respective shoulders 66, 68 of the rice basket 20 and drip tray 42 are at the upper region thereof. The shoulder 66 at the upper region of the rice basket 20 permits the rice basket 20 to locate inside the upper basket 18. In a similar manner the shoulder 68 at an upper region of the drip tray 42 permits the drip tray 42 to locate inside the base 12.

In Figure 3 there is shown a diagrammatic cross section of the food steamer of Figure 1 illustrating steam circulation. In use the water tank 32 is filled with water via aperture 36. The water then passes from the water tank 32 under gravity into the water channel 44. The heating element 46 then heats the water as it passes through the water channel 44 turning it into steam. The steam exits through the steam cap 40 and pass from the base 12 into the steam baskets 11 primarily via the duct 30 but also via holes 50 in the drip tray 42. Together the drip tray 42 and steam cap 40 define a serpentine channel 51 through which steam is transferred from the steam cap 40 to the holes 50. The steam from the holes 50 passes directly into the lower steam basket 14.

In Figure 3 the steam exits the free end of the duct 30 and enters the middle steam basket 16. The steam can then pass into the upper steam basket 18 and lower steam basket 14 via perforations in the removable floors 28, 26 of the upper steam basket 18 and middle steam basket 16 respectively. Steam also passes from the upper steam basket 18 into the rice basket 20.

The configuration of the steamer 10 permits steam to be input to the baskets 11 via an upper level inlet provided by the duct 30, and via a lower level inlet provided by the holes 50 which are fed with steam via the serpentine channel 51. Providing an upper and a lower inlet permits more even distribution on steam and hence temperature than the prior food steamer. In use the food steamer 10 produces more even cooking of food placed in the baskets 11. This is achieved by the principles of convective and conductive heat transfer.

Claims

Claims 1. A food steamer comprising a substantially closed vessel having a

base and a lid, the base including a steam generator having a low level outlet to permit steam to escape into the vessel in a lower region and a high level outlet to permit steam to escape into the vessel in an upper region, wherein the high level outlet is connected to the steam generator by a substantially upright duct having an imperforate wall.
2. A food steamer according to Claim 1, wherein the high level outlet is defined by the upright duct.
3. A food steamer according to claim 1 or claim 2 wherein the vessel includes a plurality of food containers stackable one above another on the base.
4. A food steamer according to claim 3 wherein the containers are close fitting, each container having a floor with holes to allow passage of steam therethrough.
5. A food steamer according to any of claims 3 - 4 wherein the outer wall of each container comprises a portion of the outer wall of the food steamer.
6. A food steamer according to any of claim 3 - 5, wherein the containers are annular, the duct being disposed through the containers.
7. A food steamer according to claim 6, wherein the duct is close fitting with the containers.
8. A food steamer according to any of claims 3- 7 wherein the duct is mounted on the floor of the lowermost container.
9 A food steamer according to claim 8 wherein the floor of the lowermost container has a perforated boss, the duct being mounted on said boss.
10. A food steamer according to any of claims 3 - 9 wherein the containers have an imperforate peripheral wall.
11. A food steamer according to any of claims 3 - 10, and further including a crown container adapted to be stacked on the uppermost container and underneath said lid, the high level outlet being adjacent the underside of said crown container.
12. A food steamer according to claim 11 wherein the crown container is close fitting with the vessel, and the floor of the crown container has holes to allow passage of steam therethrough, in use.
13. A food steamer according to claim 11 or claim 12 and further including an auxiliary container wherein the auxiliary container is stackable on the crown container and beneath the lid.
14. A food steamer according to any of claims 3 - 11 wherein the floor of each container is removable.
I S. A food steamer according to any preceding claim wherein the duct has a circular section.
16. A food steamer according to claim 13, wherein the duct comprises a tube of constant section and has orthogonal ends.
17. A food steamer according to any preceding claim wherein the steam generator is a flash boiler.
18. A food steamer according to any preceding claim wherein the steam generator includes a water tank and an electric heater.
19. A food steamer according to claim 16, wherein the steamer has an external aperture to permit f fling thereof.
20. A food steamer according to claim 18 or claim 19, wherein the electric heater is located beneath the water tank.
21. A food steamer according to claims 18, 19 or 20 wherein the electric heater includes a water duct having an heating element adjacent thereto.
22. A food steamer according to claim 21, wherein the water duct includes an upright steam aperture for exit of steam therefrom.
23. A food steamer according to any preceding claim, wherein a condensate tray is provided above the steam generator.
24. A food steamer according to claim 23, wherein the condensate tray is annular and defines a serpentine channel to the low level aperture.
25. A food steamer according to any preceding claim, wherein the food steamer is provided with a controller for controlling the operation of the steam generator.
26. A food steamer according to any preceding claim, wherein the food steamer is provided with a liquid crystal display.
27. A food steamer as substantially described herein with reference to the accompanying drawings.