The safety guard of electrothermal film heater
Technical field
The utility model relates to a kind of safety guard, especially a kind of safety guard that is used for electrothermal film heater.
Background technology
The liquid-heating unit of existing water dispenser adopts Electric radiant Heating Film to heat more, and the thermal conversion speed of Electric radiant Heating Film is fast, heat energy transformation efficiency height, and thermal inertia is few.Adopting Kick type temperature controller is this type of heater to be carried out temperature control avoid causing when the water dispenser circuit breaks down electrothermal film heater overheated and produce a kind of effective safety precautions of security incident.When electrothermal film heater overtemperature or dry combustion method, Kick type temperature controller moves automatic shutoff circuit rapidly, treat temperature reduce after automatic processing circuit then.
Safety guard as the disclosed a kind of electrothermal film heater of publication number CN101534581A; the exposed bimetal leaf of its Kick type temperature controller directly overlays on the insulating barrier of Electric radiant Heating Film, and the thermal actuation of bimetal leaf disconnects the power supply of electric heating lamina membranacea by the action of the make and break contact in the bimetal leaf temperature controller.The variation of the temperature sensor that this thermostat energy is sensitive is cut off the electricity supply in time, but because the thermal conversion speed of electrothermal film heater is fast, when electrothermal film heater rigidly connects energize when beginning operate as normal, the rising rapidly of Electric radiant Heating Film temperature, can make thermostat quickly take-off cut off the electricity supply, thereby influence the operate as normal of heater.
The utility model content
Technical problem to be solved in the utility model provides a kind of safety guard of electrothermal film heater; make the electric heating lamina membranacea rigidly connect energize when starting working temperature slowly evenly rise, thereby avoid thermostat take-off and influence normal heating work quickly.
The utility model solves the problems of the technologies described above the technical scheme that is adopted: a kind of safety guard of electrothermal film heater; comprise the electric heating lamina membranacea; one end of described electric heating lamina membranacea is provided with thermostat, it is characterized in that, is provided with film between described thermostat and the described electric heating lamina membranacea.
Described electric heating lamina membranacea comprises metallic plate, is coated with insulating barrier on the described metallic plate, is printed with Electric radiant Heating Film on the described insulating barrier, and described film is arranged between described Electric radiant Heating Film and the described thermostat, can slow down temperature and rise quickly, and temperature is come out equably.
Described film covers the temperature control sheet of described thermostat lower end.
Described film is the film of insulation, makes Electric radiant Heating Film can not be subjected to the influence of thermostat and burns.
Compared with prior art; advantage of the present utility model is: owing to be provided with thin film between thermostat and electric heating lamina membranacea; can prevent that the electric heating lamina membranacea from rigidly connecting energize when starting working; owing to last temperature excessive velocities makes the take-off of temperature control sheet cut off the electricity supply quickly; this film also has insulation function, can protect the Electric radiant Heating Film of electric heating lamina membranacea not to be subjected to the influence of upper end thermostat effectively.
Description of drawings
Fig. 1 is the structural representation of safety guard of the present utility model;
Fig. 2 is the end view of safety guard of the present utility model.
Embodiment
Embodiment describes in further detail the utility model below in conjunction with accompanying drawing.
Referring to Fig. 1 and Fig. 2, a kind of electrothermal film heater, comprise electric heating lamina membranacea 1, electric heating lamina membranacea 1 comprises metallic plate 11, the central authorities of metallic plate 11 are coated with insulating layer coating 12, are printed with Electric radiant Heating Film 13 on insulating barrier 12, and the wiring of Electric radiant Heating Film 13 is that principle increases density as far as possible to increase conductor length, electric heating lamina membranacea 1 caloric value is increased, and heating fast.
One end of electric heating lamina membranacea 1 is provided with junction block 14, temperature-sensing element 15 and thermostat 16, and junction block 14 is connected with the power supply (not shown), and the power source of electric heating lamina membranacea 1 heating is provided; Temperature-sensing element 15 is connected with the controller (not shown) of peripheral hardware, provides sensed temperature so that the heating power of electric heating lamina membranacea 1 is controlled; Thermostat 16 is Kick type temperature controller, and when electric heating lamina membranacea overtemperature or dry combustion method, 16 of thermostats can automatically cut power supply rapidly, play the function of safeguard protection.Preferably, Electric radiant Heating Film 13 is the rare earth metal film, and temperature-sensing element 16 is the thermistor of negative temperature coefficient.
Be provided with resistant to elevated temperatures film 17 between the temperature control sheet 161 of thermostat 16 lower ends and the Electric radiant Heating Film 13.This film 17 covers temperature control sheet 161, when electric heating lamina membranacea 1 rigidly connects energize when beginning normal heating work, because the efficiency of heating surface height of Electric radiant Heating Film 13, thermal conversion speed is fast, the local temperature of Electric radiant Heating Film 13 rise rapidly (for example reaching about 200 ℃), thereby the temperature control sheet 161 that causes thermostat 16 take-off is quickly cut off the electricity supply (the take-off temperature of thermostat is generally at 160 ℃-180 ℃), influences normal water dispenser heating function.And the use of this film 17 can slow down the rising rapidly of temperature, temperature is evenly come out lentamente, thereby guarantee that temperature control sheet 161 can not rigidly connect energize at electric heating lamina membranacea 1 and start working, take-off quickly when local temperature rises rapidly, the assurance water dispenser is worked normally.And break down when making electric heating lamina membranacea 1 uncontrolled heating when controller or its peripheral circuit, the temperature of Electric radiant Heating Film 13 will surpass the take-off temperature of thermostat 16 sustainedly and stably, and thermostat 16 will take-off and protect electric heating lamina membranacea 1.
In addition, this film 17 still insulate.Because Electric radiant Heating Film 13 be rare earth material, and cause high temperature to burn easily after temperature control sheet 161 that metal material is made contacts, film 17 is located between Electric radiant Heating Film 13 and the temperature control sheet 161 can protect Electric radiant Heating Film 13 effectively, make its be not subjected on the influence of thermostat 16.
The above only is a preferred implementation of the present utility model; should be pointed out that for the ordinary skill in the art, do not breaking away under the principle prerequisite of the present utility model; can also make various deformation and improvement, this also should be considered as protection range of the present utility model.