Electric Heating Device

Abstract

An electric heating device includes a main tube which includes multiple heating areas. Each heating area has a hating bar received therein to provide thermal energy to the liquid passing through the heating areas and to increase the temperature of the liquid. A control unit has multiple control members and each control member is electrically connected to and controls one of the heating bars. Each of the control members has a heat dissipating tube connected thereto. The multiple heating areas are cooperated respective heating bars to increase the contact areas between the liquid and the heating bars to quickly increase the temperature of the liquid.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to an electric heating device, and more particularly, to an electric heating device having multiple heating bars which heat liquid in the heating device to form multiple heating areas.

BACKGROUND OF THE INVENTION

[0002] The conventional electric heating device is disclosed in Taiwan Utility Model Patent No. M371863 which has a body comprising multiple heating members, a main pipe and multiple heat-conductive tubes therein. The heating members and the heat-conductive tubes heat the liquid in the body to achieve the purpose of increasing temperature. However, to increase the temperature of the large amount of the liquid in the body, more time and more energies are required. The efficiency for thermal conversion is too low, and the time and energy consuming is high.

[0003] Another Taiwan Utility Model Patent No. M404951 discloses a liquid heating device and generally comprises a heating pipe, a heat-conductive unit and a controller connected with the heat-conductive unit. The hating pipe includes multiple bent portions and an alloy coating is coated to the heating pipe. The heat-conductive unit comprises positive and negative members which are in contact with the alloy coating. By electrifying the alloy coating, the heat generated from the alloy coating can be quickly transferred to the heating pipe to shorten the time required to heat the liquid.

[0004] Although the disclosure of Taiwan Utility Model Patent No. M404951 improves the shortcomings of the disclosure of Taiwan Utility Model Patent No. M371863, when the alloy coating attached on the heating pipe is disabled or damaged, the whole set of the heating pipe has to be replaced. Another shortcoming is that the alloy coating has to be powered to generate heat and cannot be heated partially, so that the output energy is significant and cannot be partially controlled. Further shortcoming is that because the liquid is heated by the alloy coating, the output power of the heating device is not controlled easily, and the desired temperature of the liquid is hard to be achieved or maintained. Yet another shortcoming is that the thermal energy has to be transferred to the heating pipe from the alloy coating and then to the liquid in the heating pipe, the efficiency for thermal conversion is therefore worse and the generating heat is dissipated quickly.

[0005] The present invention intends to provide an electric heating device for heating the liquid therein and the electric heating device improves the shortcomings of the conventional electric heating devices.

SUMMARY OF THE INVENTION

[0006] The present invention relates to an electric heating device and comprises a heating unit having a main tube which has an inlet and an exit. Multiple heating areas are formed between the inlet and the exit of the main tube. Each heating area has a hating bar received therein and a spiral path is defined in each heating area. A first temperature sensing member is connected to the main tube and located close to the inlet. A control unit has a circuit board which has multiple control members electrically connected thereto. Each of the control members is electrically connected to and controls one of the heating bars. Each of the control members has a heat dissipating tube connected thereto which is connected between the inlet of the main tube and a fluid switch. The fluid switch is electrically connected to the circuit board.

[0007] Preferably, the heating areas are located in parallel to each other, and the heating bars are located in parallel to each other.

[0008] Preferably, the output power of each of the heating bar is gradually reduced from the heating bar located close to the inlet of the main tube toward the heating bar located close to the exit when total output power of all of the heating bars is not changed.

[0009] Preferably, a second temperature sensing member is connected to the main tube and located close to the exit. The second temperature sensing member is electrically connected to the control unit.

[0010] Preferably, the control members are fluid brakes.

[0011] Preferably, the control members are threadedly connected to the heat dissipating tube.

[0012] Preferably, the control unit is an electronic control unit.

[0013] One aspect of the present invention is that there are multiple heating areas cooperated with respective heating tubes, so that the liquid in the device absorb thermal energy quickly to have higher thermal conversion.

[0014] Another aspect of the present invention is that by using the electronic control unit, the temperature can be precisely and quickly changed and controlled so as to maintain the desired/specified. temperature.

[0015] Further aspect of the present invention is that the heat generated by the control members is removed by the heat dissipating tube to prevent the control members from overheated.

[0016] Still another aspect of the present invention is that the heat dissipating tube absorbs the heat generated by the control members to pie-heat the liquid to have better efficiency.

[0017] Further another aspect of the present invention is that under the setting that the total output power of all of the heating bars is riot changed. The output power of each heating bar can be set to be different to have higher efficiency of thermal conversion. The energy is saved and the time required to achieve a pre-set temperature is reduced.

[0018] Yet another aspect of the present invention is that each of the heating areas is heated by the respective heating bar, so that the individual heating bar can be replaced.

[0019] Yet further aspect of the present invention is that each of the heating areas has a spiral path to increase the time period that the liquid passes through the heating bars, so that the liquid can absorb sufficient thermal energy to quickly increase the temperature.

[0020] The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows the parts of the electric heating device of the present invention;

[0022] FIG. 2 is another view to show the parts of the electric heating device of the present invention;

[0023] FIG. 3 shows that the heating area has a spiral path;

[0024] FIG. 4 shows the operational status of the electric heating device of the present invention;

[0025] FIG. 5 shows the heating bars are set to have different output powers; and

[0026] FIG. 6 shows the relative positions of the control members and the heat dissipating tube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] Referring to FIGS. 1 and 2, the electric heating device of the present invention comprises a heating unit 1 having a main tube 11 through which liquid passes. The main tube 11 has an inlet 111 and an exit 112, so that the liquid enters the main tube 11 from the inlet 111 and flows out from the exit 112 after being heated. Multiple heating areas "A" are formed between the inlet 111 and the exit 112 of the main tube 11. Each heating area "A" has a hating bar 12 received therein so as to heat the liquid passing through the heating area "A". Further referring to FIG. 3, a spiral path 113 is defined in each heating area "A" to increase the time period that the liquid passes through the heating bar 12, so that the liquid can absorb sufficient thermal energy to quickly increase the temperature. The heating bar 12 generates heat from its surface and the liquid absorbs the heat from the surface of the heating bar 12 when the liquid passes through the heating area "A". A first temperature sensing member 13 is connected to the main tube 11 and located close to the inlet 111 so as to sense the temperature of the liquid entering the main tube 11. A second temperature sensing member 14 is connected to the main tube 11 and located close to the exit 112 so as to sense the temperature of the liquid about to flow out from the exit 112. The heating areas "A" are arranged in parallel to each other, and the heating bars 12 are arranged in parallel to each other so as to decrease the volume of the heating unit 1.

[0028] A control unit 2 includes a circuit board 21 which is an electronic circuit board, and temperature-control programs are built in the circuit board 21 which belongs to an electronic control and responses more quickly and controls different ranges of temperature when compared with an electro-mechanical control. The circuit board 21 has multiple control members 22 electrically connected thereto which are triacs. Each of the control members 22 is electrically connected to and controls one of the heating bars 12 so as to control the heating bars 12 to be activated or not to be activated. Each of the control members 22 has a heat dissipating tube 23 connected thereto which removes the heat of the control member 22 corresponding thereto. The dissipating tube 23 is connected between the inlet 111 of the main tube 11 and a fluid switch 24. The fluid switch 24 electrically connected to the circuit board 21 so as to send information whether fluid passes through the fluid switch 24. The liquid enters from the fluid switch 24 and passes through the dissipating tube 23 and enters the main tube 11 so as to be heated by the heating processes controlled by the control unit 2.

[0029] As shown in FIG. 4, there are six heating areas "A" and six heating bars 12 in this embodiment. The control unit 2 sets the temperature that the liquid is heated, such as 40.degree. C. When the fluid switch 24 detects the fluid passing thereby, a signal is sent to the circuit board 21 of the control unit 2 and the control members 22 are activated to operate the heating bars 12. The first temperature sensing member 13 detects the temperature of the liquid before entering the main tube 11, such as 20.degree. C. The programs in the circuit board 21 of the control unit 2 calculate the total power for the required output temperature. Each control member 22 controls the corresponding heating bar 12 and outputs required power so that the sum of the output powers of all of the heating bars 12 is the same as the calculated total power. The liquid is heated in the main tube 11. The second temperature sensing member 14 detects the temperature of the heated liquid and sends a signal to the circuit board 21 of the control unit 2 until the preset temperature is reached.

[0030] There are multiple heating areas "A" cooperated with respective heating tubes 12 so that the liquid in the main tube 11 contact the larger contact area with the heat source to absorb thermal energy quickly. The pre-set temperature can be quickly reached and the device is suitable for electric water heater. Under the arrangement of the present invention, the output temperature is stable, the required heating time is short, and the temperature can be adjusted quickly.

[0031] As shown in FIG. 5, in order to increase the efficiency of the thermal conversion, the output power of each heating bar 12 can be individually set when the total output power is not changed. More specifically, the temperature of the liquid close to the inlet 111 of the main tube 11 is lower so that higher power is needed to increase the temperature of the liquid. The temperature of the liquid close to the exit 112 of the main tube 11 is higher so that only smaller power is needed to increase the temperature of the liquid. In other words, the output powers of the two heating bars 12 located close to the inlet 111 needs to be higher than the output powers of the two heating bars 12 located close to the exit 112. The two heating bars 12 located between the inlet 111 and the exit 112 are set to have medium output powers. That is to say, generally the output power of each of the heating bar 12 is gradually reduced from the heating bar 12 located close to the inlet 111 of the main tube 11 toward the heating bar 12 located close to the exit 112 when total output power of all of the heating bars 12 is not changed. By this way, the efficiency for increasing the temperature of the liquid is increased and the energy is saved.

[0032] As shown in FIG. 6, when the temperature generated from the heating bars 12 is too high, the control members 22 may be damaged. In order to protect the control members 22, the control members 22 are fixedly connected to the heat dissipating tube 23 so as to remove the heat from the control members 22. Preferably, the control members 22 are threadedly fixed to the heat dissipating tube 23. More specifically, the liquid passing through the dissipating tube 23 absorbs the heat generated from the control members 22, so that the operating temperature of the control members 22 is kept at lower temperature. Besides, the liquid absorbs the heat from the control members 22 before it enters into the main tube 11, so that the liquid is initially heated, and this is helpful for the following heating processes. That is to say, the operating temperature of the control members 22 can be controlled, and the heat to be removed from the control members 22 is used to pre-heat the liquid to save the energy and to reduce the operation time required.

[0033] While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.

Claims

1. An electric heating device comprising: a heating unit having a main tube which has an inlet and an exit, multiple heating areas formed between the inlet and the exit of the main tube, each heating area having a hating bar received therein and a spiral path defined in each heating area, a first temperature sensing member connected to the main tube and located close to the inlet; and a control unit having a circuit board which has multiple control members electrically connected thereto, each of the control members electrically connected to and controlling one of the heating bars, each of the control members having a heat dissipating tube connected thereto which is connected between the inlet of the main tube and a fluid switch, the fluid switch electrically connected to the circuit board.

2. The device as claimed in claim 1, wherein the heating areas are located in parallel to each other, and the heating bars are located in parallel to each other.

3. The device as claimed in claim 2, wherein an output power of each of the heating bar is gradually reduced from the heating bar located close to the inlet of the main tube toward the heating bar located close to the exit when total output power of all of the heating bars is not changed.

4. The device as claimed in claim 1, wherein a second temperature sensing member is connected to the main tube and located close to the exit, the second temperature sensing member is electrically connected to the control unit.

5. The device as claimed in claim 1, wherein the control members are triacs.

6. The device as claimed in claim 1, wherein the control members are threadedly connected to the heat dissipating tube.

7. The device as claimed in claim 1, wherein the control unit is an electronic control unit.