Container heating device
The compact heating device addresses imprecision and safety issues of existing heating technologies by using dry conduction and safety features for precise temperature control, enhancing test reliability and safety.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- LOREAL SA
- Filing Date
- 2024-02-16
- Publication Date
- 2026-04-17
AI Technical Summary
Existing heating devices for containers, such as laboratory equipment and common devices like wax heaters or bottle warmers, are imprecise, costly, and pose safety risks, leading to unreliable test results and potential burns.
A compact, lightweight heating device that heats containers by dry conduction, using a ceramic-coated heating sleeve with a clamp and temperature control, ensuring precise temperature regulation and safety features like a lid-activated switch to prevent overheating and accidental burns.
The device allows rapid, precise temperature control, reducing the risk of burns and improving test reliability by minimizing temperature variability and ensuring safe, efficient heating.
Smart Images
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Abstract
Description
Title of the invention: Container heating device technical field
[0001] The present invention relates to a device, and more generally an assembly, for enabling the controlled heating of a container. In particular, the present invention relates to a device for heating a test sample, for example, a biological material placed in solution. Previous technique
[0002] There are many heating devices designed to heat a container and which can operate by conduction or convection. These include, among others, bottle warmers, wax heaters, thermostatic baths, electric heating mantles, and hot plates. These various devices are used in extremely varied contexts and conditions. In particular, laboratory equipment such as thermostatic baths, electric heating mantles, or laboratory hot plates requires careful handling. Furthermore, this equipment has a significant cost. Common equipment, such as wax heaters or bottle warmers, is, on the other hand, very limited in its use and relatively imprecise in the temperatures reached.
[0003] However, in the case where it is desired to carry out tests involving chemical reactions, an inaccuracy in the temperature is likely to lead to variability in the results, impairing their interpretation and the reliability of the test.
[0004] In addition, devices operating on the principle of a water bath entail a greater risk of burns in the event of accidental tipping, due to the projection of the liquid constituting the bath. Description of the invention
[0005] There is a need for a heating device that allows a container to be heated in a controlled manner, which is compact, lightweight and accessible to the general public, and which is safe to use.
[0006] There is also a need for an improved heating device that allows a given temperature to be reached quickly.
[0007] There is also a need for a device to maintain a given temperature without exceeding it.
[0008] The invention aims to meet all or part of these needs. Summary of the invention
[0009] The invention relates to an assembly consisting of a container and a device for heating the container, the heating device comprising:
[0010] -a case;
[0011] - a heating element contained in the housing and defining a receiving cavity of the container, intended to heat the latter by dry conduction.
[0012] The assembly according to the invention advantageously limits the risk of burns, due to the absence of liquid at the interface between the container and the heating element. Thus, in the event of accidental tipping of the device, if the container is closed, there is no risk of splashing, unless the container breaks.
[0013] The device according to the invention can allow the temperature to be controlled quickly and precisely, and by lower values.
[0014] Such a device can also make it possible to reach a given temperature in a reduced time.
[0015] In general, unlike bottle warmers, wax warmers, or bain-maries, dry contact conduction, meaning without a heating fluid and with low inertia, makes the temperature rise much faster. Furthermore, the invention provides a heating system for a compact, lightweight, and user-safe container.
[0016] The cavity may have a shape complementary to the external shape of said container. This maximizes the heat exchange surface area between the container and the heating element.
[0017] Preferably, more than 80% of the container is inserted into the cavity, and even better, more than 90% of the container is inserted into the cavity. This facilitates securing the container in the device and covering the container with a lid, thus reducing the risk of breakage in the event of accidental tipping of the device. It also allows for a large heat exchange surface and a more homogeneous temperature of the container wall.
[0018] Such an assembly makes it possible in particular to obtain a compact assembly while maximizing heat exchange and thus improving thermal performance.
[0019] The container may in particular be a tubular container having an outside diameter greater than or equal to 2 cm and less than or equal to 3 cm.
[0020] The assembly is particularly suitable for carrying out tests on samples, quickly and easily, without the need for laboratory equipment.
[0021] The heating element may include a heating sleeve composed of a ceramic-coated heating resistance.
[0022] In general, the resistance is preferably covered with a material with low mass and low thermal inertia.
[0023] The heating sleeve can be a split collar.
[0024] The heating element may include a clamp for the heating sleeve, the clamp adjusting the inner diameter of the heating sleeve so that the container fits into the cavity of the heating element with a sufficiently small gap to allow heating of the container by dry conduction. Heat losses are thus advantageously limited. The clamp may be adjusted by tightening a screw, a temperature sensor such as a thermistor being positioned in direct contact with said screw. Such an arrangement allows for a good temperature reading of the clamp from the temperature sensor.
[0025] In particular embodiments, the assembly includes a temperature regulator configured to heat the container to a predefined temperature, and optionally maintain this predefined temperature for a predetermined period of time, the temperature being within the range [70°C; 110°C], preferably within the range [90°C; 100°C], and preferably, this temperature is maintained for a period of time greater than or equal to 3 minutes and / or less than or equal to 10 minutes.
[0026] This temperature control can help limit the risk of scalding by preventing certain temperatures from being exceeded. The control can also prevent temperatures from exceeding levels that could damage the contents of the container by heating it to an excessively high temperature.
[0027] The temperature controller can be a PID (proportional, integral, derivative) controller. In particular, the PID controller can have a proportion gain Kp between 0.2 and 0.4 and a proportion gain Ki between 0.05 and 0.15.
[0028] The housing may include a base having an opening through which the container is intended to be introduced into the base, and a cover hinged on the base between an open position and a closed position.
[0029] In particular, the hood can be mounted pivoting around an axis of rotation substantially parallel to an axis of insertion of the container in the base and in the cavity of the heating element.
[0030] In the closed position, the hood retains the container in the housing, and limits, or even blocks, access to hot surfaces of the device or container.
[0031] In addition, the heating device may include a contact switch arranged so that the closed position of the switch is triggered by rotation of the cover, when the latter pivots into the closed position, the switch being configured so as to prevent heating when the switch is open.
[0032] Thus, the heating of the container can be conditional upon the lid being closed, improving user safety. This also helps to limit energy consumption, by stopping the heating as soon as the device is opened. This can also limit handling, if necessary, by avoiding the need to press a button to stop the heating.
[0033] In embodiments of the invention, the hood is fixed to a rod positioned inside the housing and comprising a stop element intended to come into contact with the switch when the hood is in the closed position, the switch being in the closed position when it is in contact with the stop element.
[0034] The assembly may further include a thermally insulating cap for sealing the container. This advantageously limits heat loss and facilitates handling of the container.
[0035] The hood may have a lateral opening to allow it to engage with a container not fully inserted into the cavity. This allows easy access to the container's cap for removal from the device once the hood is in the open position.
[0036] The heating element can be disposed in a support thermally insulating the heating element from the housing, the support being fixed to an upper part of the housing, and in particular when the housing has a base and a cover, the support is fixed to an upper part of the base.
[0037] To ensure electrical safety for the heating device, a fuse and an earth wire may be positioned in a lower part of the support. In particular, the fuse may be a thermal fuse or a resettable safety thermostat, also known as a resettable Klixon.
[0038] The base of the support may include a slot having a general shape of an angular sector (i.e., a quarter), the apex of the angular sector being located substantially at the center of the base of the support. Preferably, the slot has a widening at the apex of the angular sector, the opening angle of the angular sector being greater than or equal to 15° and less than or equal to 45°. Brief description of the drawings
[0039] The invention will be better understood upon reading the detailed description that follows, a non-limiting example of its implementation, and upon examination of the accompanying drawing, in which
[0040] [Fig. 1] is a longitudinal section of an example of a heating device according to the invention,
[0041] [Fig.2] represents a heating element,
[0042] [Fig.3] represents the heating device in the open position (Fig. 3b) and in closed position (Fig 3b),
[0043] [Fig.4] is an exploded view of the heating device,
[0044] [Fig.5] shows a cross-section of the heating device,
[0045] [Fig.6] shows a top view and a bottom view of the element support heated,
[0046] [Fig.7] is a graph illustrating an example of a heating law.
[0047] In the following description, identical elements or elements with analogous functions They bear the same reference symbol. Their description is not repeated alongside each figure; only the main differences between the embodiments are mentioned. Detailed description
[0048] Figures 1 to 6 illustrate an assembly 1 according to the invention, comprising a container 2 and a container heating device 3.
[0049] The heating device 3 comprises a housing 30 having a base 35 and a cover 36, and a heating element 32 contained within the housing, defining a receiving cavity 34 for the container. The cavity 34 is arranged to allow the container to be heated by dry conduction, that is, without liquid at the interface between the heating element and the container, unlike a water bath. The base comprises an upper part 351 and a lower part 352.
[0050] The container 2 can be, as illustrated, a tubular container, preferably with rotational symmetry. Preferably, the container has a maximum outside diameter D greater than or equal to 2 cm and less than or equal to 3 cm.
[0051] The container may in particular be a test tube or a sample tube, in particular a standard one.
[0052] The container may be made of mineral glass or thermoplastic material resistant to the temperature of use, in particular polypropylene, polyethylene.
[0053] Preferably, the container is made of a material that is resistant to the temperature of use and chemically neutral.
[0054] Chemically neutral means a material that does not produce any chemical reaction when it comes into contact with a composition intended to be introduced into the container.
[0055] Preferably, the container is made of a transparent or semi-transparent material.
[0056] In some embodiments, the container may be made of a metal alloy, which may be opaque. The nature of the container material may improve heat conduction within the container.
[0057] The container may in particular be intended to contain a solution for carrying out a chemical test, requiring the heating of the solution to a given temperature and / or for a given duration.
[0058] The biological material to be analyzed can be inserted into the container, for example consisting of hair fibers.
[0059] In particular, the assembly according to the invention can be arranged so as to allow the chemical analysis of hair.
[0060] The container can be closed by a thermally insulating sealing cap 22, as illustrated in [Fig. 1]. In particular, the cap can be formed, at least in part, by a thermally insulating foam 22i. The cap can comprise a central portion 222, for example made of elastomer or a non-cellular, flexible plastic material, which attaches to the neck of the container to close it, and a concentric outer portion, formed by said insulating foam 22i, which extends over more than the height of the central portion.
[0061] The height of the container and that of the cavity are such that preferably more than 70%, better more than 80%, even better more than 90% of the container is contained in the cavity 34.
[0062] The outer surface of the part of the container received in the cavity can come into direct contact with the heating element 32, except for the insertion gap.
[0063] As illustrated in [Fig.2], the heating element 32 may include a heating sleeve 38 consisting of a ceramic-coated resistance.
[0064] The heating element 32 can be connected to a power supply, via a connector 62.
[0065] The heating sleeve 38 can be a split collar, as illustrated.
[0066] A clamp 40 can clamp the heating sleeve 38, the clamp adjusting the inner diameter d of the heating sleeve during manufacturing so that the container fits into the cavity of the heating element with a gap small enough to allow heating of the container by dry conduction and insertion or extraction of the container without forcing.
[0067] The clamping collar 40 can notably be adjusted by tightening a screw 42. In addition, a thermistor 44 or any other temperature sensor can be positioned in direct contact with said screw 42. An earth wire 74 can be connected to the screw 42, to ensure electrical safety.
[0068] The heating element 32 can be disposed in a support 48 that thermally insulates the heating element from the housing, as illustrated. In particular, the support 48 may include thermal insulation 46 that at least partially encloses the heating element.
[0069] A thermal fuse 66 is preferably positioned in the lower part of the support.
[0070] The base of the support may include a slot 68 having a general angular sector shape. The apex of this sector is preferably located substantially at the center of the base of the support. In addition, the slot 68 may include a widening 70 at the apex of the sector. The opening angle 0 of the angular sector may be greater than or equal to 15° and less than or equal to 45°. Such a support 48 allows deformability and the possibility of adjusting its inner diameter by tightening a screw 72 which engages with two opposite uprights of the support 48. The latter can thus be tightened onto the heating element.
[0071] The support 48 can be fixed, as illustrated in [Fig.6], to an upper part of the housing 30, in particular to the upper part 351 of the base.
[0072] The support 48 is for example screwed to the upper part of the base 35, by means of screws 50, as illustrated in [Fig.4].
[0073] The hood 36 is movable, as shown in [Fig.3], between an open position shown in Figure 3a and a closed position shown in Fig 3b.
[0074] The hood 36 may have a side opening 52.
[0075] The hood 36 can be mounted pivoting about a rotation axis X substantially parallel to an insertion axis Y of the container in the cavity of the heating element. The hood pivots in a horizontal plane.
[0076] A contact switch 54 can be positioned in the heating device, as seen in [Fig.5], this switch being for example fixed on the lower part 352 of the base, the switch 54 being arranged so that the closed state of the switch is triggered by rotation of the cover, when the latter pivots into the closed position, the control circuit of the heating element being configured so as to prevent heating when the switch is open.
[0077] The hood 36 can be fixed to a rod 56 positioned inside the housing and having a cam 58 intended to come into contact with the switch 54 when the hood is in the closed position, the switch being brought into the closed position by the cam 58.
[0078] Preferably, the device includes a temperature regulator 60 configured to control the heating element so as to heat the container to a predefined temperature, and maintain this predefined temperature for a predetermined period of time, the temperature being within the range [70°C; 110°C], better within the range [90°C; 100°C] for a period of time greater than or equal to 3 minutes and / or less than or equal to 10 minutes.
[0079] The temperature controller 60 may include a microcontroller, which drives, for example via an optocoupler, a power component, enabling the control of the heating element's power supply based on measurements detected by the thermistor and the control law. The power component may be an optotriac.
[0080] The heating device may include a visual or audible indicator 64 informing the user of the device's operating status. For example, visual or audible indications may indicate that the device is heating, that the temperature The predefined threshold has been reached, the predetermined time period has elapsed, and the device is open. In particular, visual or audible indications may emanate from a screen, an LED, or a buzzer.
[0081] The temperature controller may in particular be a PID (proportional, integral, derivative) controller, whose proportion gain Kp is in particular between 0.2 and 0.4 and therefore the proportion gain Ki is in particular between 0.05 and 0.15.
[0082] The PID controller allows for a heating law in the form of a ramp R. The graph in [Fig.7] shows, with a measurement step of 500 ms, curves Cl, C2, C3 which trace the evolution of the temperatures obtained at the level of the contents of the container over time during the operation of the heating device illustrated in figures 1 to 6. The curves Cl to C3 were obtained during three successive tests with the objective of heating the container to a setpoint temperature of 100°C and then maintaining this temperature for a period of at least 5 minutes.
[0083] Curve C4 corresponds to the difference between curves Cl and C3. These curves show that the predefined temperature of 100°C can be reached relatively quickly and maintained, with a degree of accuracy of about 10°C.
Claims
Demands
1. Assembly (1) consisting of a container (2) and a container heating device (3), the heating device comprising: - a housing (30); - a heating element (32) contained in the housing and defining a container receiving cavity (34), intended to heat the container by dry conduction, - a cover (36) intended to cover the container present in the cavity (34).
2. Together according to the preceding claim, the container (2) being a tubular-shaped container having an outside diameter (D) greater than or equal to 2 cm and less than or equal to 3 cm.
3. Assembly according to any one of claims 1 and 2, wherein the housing (30) comprises a base (35) having an opening through which the container is intended to be introduced into the base, the hood (36) being hinged on the base between an open position and a closed position.
4. Assembled according to claim 3, the hood (36) being mounted pivotally about an axis of rotation (X) substantially parallel to an insertion axis (Y) of the container in the base and in the cavity of the heating element.
5. Assembly according to any one of claims 3 and 4 wherein the heating device comprises a contact switch (54) arranged so that the closed position of the switch is triggered by rotation of the hood, when the latter pivots into the closed position, the switch being configured so as to prevent heating when the switch is open.
6. Assembly according to the preceding claim, the hood being fixed to a rod (56) positioned inside the housing and comprising a stop element (58) intended to come into contact with the switch when the hood is in the closed position, the switch being in the closed position when it is in contact with the stop element.
7. Together according to any one of claims 3 to 6, the hood (36) comprising a side opening (52).
8. Assembly according to any one of the preceding claims wherein the heating element (32) comprises a heating sleeve consisting of a ceramic-coated heating resistance.
9. Assembly according to the preceding claim, the heating sleeve being a split collar.
10. In assembly according to any one of claims 8 and 9, the heating element comprises a clamping collar (40) for the heating sleeve, the clamping collar adjusting the inner diameter of the heating sleeve so that the container fits into the cavity of the heating element with a clearance small enough to permit heating of the container by dry conduction.
11. Assembly according to the preceding claim, the collar being adjusted by tightening a screw, a temperature sensor (44) such as a thermistor being positioned in direct contact with said screw.
12. Assembly according to any one of the preceding claims, comprising a temperature regulator (60) configured to heat the container to a predefined temperature, and optionally maintain this predefined temperature for a predetermined period of time, the temperature being within the range [70°C; 110°C], preferably within the range [90°C; 100°C], preferably the temperature being maintained for a period of time greater than or equal to 3 minutes and / or less than or equal to 10 minutes.
13. Together according to claim 12, the temperature controller (60) is a PID (proportional, integral, derivative) controller, whose proportion gain Kp is in particular between 0.2 and 0.4 and whose proportion gain Ki is in particular between 0.05 and 0.
15.
14. Assembly according to any one of the preceding claims comprising a thermally insulating container closure stopper (22).
15. Together according to any one of the preceding claims, the heating element being disposed in a support (48) thermally insulating the heating element from the housing, the support being fixed to an upper part (35i) of the housing, in particular when the housing includes a base and a cover, the support is fixed to an upper part of the base.
16. Assembly according to the preceding claim in which a fuse (66) and an earth wire are positioned in a lower part of the support.
17. Together according to any one of claims 15 and 16, the base of the support having a slot (68) having a general angular sector shape, the vertex (70) of the angular sector being 11 located approximately in the center of the support base, preferably the slot having an enlargement at the top of the angular sector.
18. Together according to the preceding claim, the angle (0) of opening of the angular sector being greater than or equal to 15° and less than or equal to 45°.