Heating agent pack and sauna stove for heating agent pack
The sauna stove using calcium oxide and water reaction generates high-temperature steam safely and efficiently, addressing space and safety concerns in bathroom sauna devices, enhancing steam production and handling without fire or electricity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- 木村 力也
- Filing Date
- 2025-07-31
- Publication Date
- 2026-06-16
AI Technical Summary
Conventional sauna devices using fire, electricity, or unsuitable heating agents fail to provide a safe, high-temperature steam generation and efficient space utilization in bathroom settings, posing risks of fire, smoke, electric shock, and inadequate steam production.
A sauna stove utilizing the thermal reaction between calcium oxide and water, packaged in a filter, generates steam and is designed for easy handling, with a perforated tray for water pouring and a sauna stone-like shape, ensuring safe and efficient steam production without fire or electricity.
The system provides a safe, high-temperature steam generation without fire or electricity risks, utilizing bathroom space efficiently, and offers a risk-free sauna experience with no need for additional space or installations, while ensuring easy handling and steam distribution.
Smart Images

Figure 2026097713000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a sauna device that can be used in a household bathroom.
Background Art
[0002] Conventional sauna devices include a sauna stove that uses fire to burn firewood or fuel.
[0003] As a non-fire-using device, there is a stove using an electric heater as in Patent Document 1.
[0004] Also, as a household sauna, there is an individual room type as in Patent Document 2.
[0005] As an example of using the heat reaction of calcium oxide, aluminum powder, and water, which is the same as that of the present invention, as a heating agent, there is a heating agent described in Patent Document 3. However, the capacity and planar shape are not suitable for sauna applications aimed at releasing more high-temperature steam. The water enclosed with the heating agent in the heating container is only used for warming food and beverages.
[0006] Other heating agents that are popular for household use include those using iron powder or oxidizable metals such as a heat pack or as in Patent Document 4. However, they are not suitable for sauna applications in terms of calorific value and steam generation amount, etc., and are different from the heating agent using calcium oxide.
Prior Art Documents
Patent Documents
[0007]
Patent Document 1
Patent Document 2
Patent Document 3
Patent Document 4
[0008] By utilizing the space in the bathroom, we create a sauna stove that is safe to use in the bathroom, does not use fire or produce smoke, and does not use electricity, so there is no risk of electric shock even when placed in a wet area. We also provide a heating agent pack that acts as a sauna stone, generating a large amount of steam and having a shape that is easy to handle with tongs when heated. [Means for solving the problem]
[0009] This system utilizes the thermal reaction between calcium oxide and water, which is used in heating agents for bento boxes and other food products. The heating agent is packaged in a filter that can filter water and steam, and this heating agent pack is placed in a sauna stove with a perforated tray for pouring water over it, which then generates heat in the bathroom. [Effects of the Invention]
[0010] By utilizing the bathroom space, no additional space is needed. Since no fire is used, there is no risk of fire or carbon monoxide poisoning, and there is no need to worry about stains from charcoal or soot. There is also no need to install a chimney. Furthermore, since no electricity is used, there is no risk of electric shock or water damage, and there is no need for electrical outlets or cables. You can enjoy a sauna in your own bathroom. [Brief explanation of the drawing]
[0011] [Figure 1] This is a schematic diagram of the entire present invention. [Figure 2] This is an explanatory diagram of the sliding tray in the sauna stove of the present invention. [Figure 3] This is a schematic diagram of the heat-generating pack of the present invention. [Modes for carrying out the invention]
[0012] Regarding the heating agent pack (1), the main material is calcium oxide, which is used in devices for warming bento boxes at train stations and in rice warmers as disaster preparedness items. By mixing in aluminum powder, the rate of thermal reaction and temperature when it reacts with water are made suitable for saunas.
[0013] To react calcium oxide and aluminum powder with water, the calcium oxide and aluminum powder are enclosed in a filter that filters out water or water vapor (8), and the internal substance mixed with water is less likely to leak out of the packaging, thus making it less likely to flow into drains, etc. This constitutes the heat-generating agent pack of the present invention.
[0014] Since the volume inside the packaging increases when calcium oxide reacts with water, a stretchable filter is preferable. If the filter's effectiveness is compromised by expansion, leave a margin (9) to account for the expansion, or stack the filters without sewing them together and then wrap them with a stretchable material, even if it does not provide filtration.
[0015] The heating agent pack has a three-dimensional structure that mimics a sauna stone, making it easy to grasp with tongs even when it is hot. A triangular shape, like a rice ball (Figure 3), is even preferable because it makes it easier to pack multiple packs in an alternating pattern in a box when it is made into a product. Furthermore, a three-dimensional shape reduces the contact area between the bottom and the tray, increasing the surface area from which steam can escape and making it easier for steam to escape through gaps even when several packs are stacked on top of each other. With a flat shape, the surface area in contact with the tray and other packs is large, which limits the escape route for the steam and makes it difficult for the steam to liquefy and be released into the air.
[0016] Additionally, shapes such as indentations towards the center of the heating element pack can be considered to allow water to spread more easily to the center of the pack, or to increase the surface area for steam generation.
[0017] Use heat-sensitive dyes or thermochromic materials that change color with heat so that you can visually determine whether it is at a high temperature. This allows you to visually confirm that it has cooled down and tidy it up. It is preferable to be intuitive, such as being black or gray imitating a sauna stone at normal temperature and turning red at high temperature.
[0018] When this heating agent pack reacts with water, it gets hot due to a heat reaction and generates high-temperature steam, thus serving as an actual sauna stone.
[0019] It would be good to have a type that allows you to enjoy the fragrance by mixing flavors such as mugwort into the heating agent pack or the filter of the packaging.
[0020] Also, since hydrogen is generated by the reaction of calcium hydroxide and aluminum, antioxidant effects on the human body can be expected by inhaling through breathing. However, since there is a risk of explosion when a fire source approaches hydrogen, it is necessary to pay attention to the amount of hydrogen generated.
[0021] It would be even better to have a mechanism that allows recycling after using this heating agent pack, such as collecting it and using calcium aluminate for cement or heating calcium hydroxide at high temperature to return it to calcium oxide.
[0022] Regarding the sauna stove for the heating agent pack, place an appropriate number of heating agent packs on the tray (2) and pour water over them from above, like pouring hot water, to cause a heat reaction of the heating agent. To minimize the temperature drop of the heating agent, warm water is preferable to cold water.
[0023] The trays (2, 7) have countless holes so that the water poured from above can be drained downward. Also, this tray is in the form of a box (5) that surrounds it on all sides, which can prevent the heating agent pack from falling and store water.
[0024] Furthermore, by making the perforated tray a double-layered structure, one side can be slid open by pulling the sliding handle (4) to completely block the holes (10). This allows for control over the flow of water into the pack by blocking the holes and preventing drainage. It can also be used when immersing the pack in water to cool it down after use.
[0025] By incorporating germanium into materials such as the tray (2) of the sauna stove for the heating pack, it is expected that the germanium will receive heat from the heating pack and emit far-infrared rays, thereby warming the human body more effectively. Furthermore, germanium may be included in the heat-generating pack of the present invention.
[0026] A sauna stove should have legs (6) to make it easier to handle the heating element packs, and this also raises the tray off the ground, allowing for smoother drainage and preventing the ground from becoming excessively hot. Furthermore, a design that allows the stove to be folded when not in use is preferable.
[0027] The sauna stove is intended to be placed in the shower area of the bathroom, but care should be taken to ensure that its placement does not block the bathroom door or emergency escape routes.
[0028] It is best to install a handle (3) made of a highly insulating material so that the device can be moved even when the heating element is generating heat.
[0029] Filling the bathtub with water to create a cold bath allows you to take a dip after the sauna, and also helps you react calmly if you get burned or if the bathroom becomes unexpectedly hot.
[0030] It is also preferable to divide the space with a shower curtain or similar to efficiently heat the sauna area. Furthermore, it is best to turn off or reduce the volume of the bathroom's exhaust fan to prevent steam from escaping. [Examples]
[0031] Use a heating pack and a sauna stove for heating packs in your home bathroom. [Examples]
[0032] The present invention's heat-generating pack and sauna stove for heat-generating packs can be used even in sauna tents used for outdoor purposes. [Examples]
[0033] By closing the holes in the drip tray of a sauna stove or by placing a heating pack in a pot or other container with plenty of water and heating it together with herbs or Chinese medicine, you can use it as a substitute for a mugwort steam bath. [Industrial applicability]
[0034] The heating agent pack and sauna stove for the heating agent pack according to this invention can be sold as products. They can also be rented along with sauna tents at outdoor facilities. [Explanation of Symbols]
[0035] 1. Heating pack 2. Top of the tray 3. Handle 4. Handle for sliding 5. Box surrounding the tray 6 pairs 7. Bottom of the drip tray 8. Packaging of the filter 9. Margins that account for expansion 10 Cross-section of the sliding tray that collects water, viewed from the side.
Claims
[Claim 1] The invention described in the specification.