Heating device using photodetector to detect temperature and method for protecting the same

Patent metadata

Field	Value
Publication number	US-9377214-B2
Application number	US-201414159595-A
Country	US
Kind code	B2
Filing date	Jan 21, 2014
Priority date	Jan 21, 2014
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A heating device includes a housing having a flow channel, a heater disposed in the flow channel, an optical rod, a light guider and a photodetector. The optical rod has a transparent body, a first end portion, and a second end portion located inside the housing. The light guider is provided at the second end portion for guiding lights emitted by the heater toward the first end portion. The photodetector is located around the first end portion and faces the second end portion for indirectly receiving the lights emitted by the heater to the light guider through the transparent body. The temperature of the heater can be measured efficiently and timely by using the photodetector having a high responding speed, such that an overheat or damage of the heater can be prevented by controlling the heater based on the measured temperature.

First claim

What is claimed is:

1. A heating device comprising:
a housing provided at an inside thereof with a flow channel for flow of working fluid;
an electric heater disposed in the flow channel and being capable of emitting lights;
an optical rod having a transparent body, a first end portion, and a second end portion opposite to the first end portion and located inside the housing;
a light guider provided at the second end portion of the optical rod and facing the electric heater for receiving the lights emitted by the electric heater and guiding the lights toward the first end portion of the optical rod; and
a photodetector located adjacent to the first end portion of the optical rod and facing the second end portion of the optical rod for indirectly receiving the lights emitted by the electric heater to the light guider through the transparent body of the optical rod and generating a detection signal corresponding to a temperature of electric heater.

2. The heating device as claimed in claim 1 , wherein the light guider is a translucent surface provided at the transparent body.

3. The heating device as claimed in claim 2 , wherein the translucent surface is a rough surface.

4. The heating device as claimed in claim 2 , wherein the optical rod has a circumference surface, a first end surface, and a second end surface opposite to the first end surface; the translucent surface is provided at a part of the circumference surface adjacent to the second end surface; the photodetector is located adjacent to and facing the first end surface.

5. The heating device as claimed in claim 4 , wherein the translucent surface is further provided at the second end surface.

6. The heating device as claimed in claim 5 , wherein the second end surface is configured as an inclined surface relative to the circumference surface.

7. The heating device as claimed in claim 2 , wherein the optical rod has a circumference surface, a first end surface, and a second end surface opposite to the first end surface; the second end surface is configured as an inclined surface relative to the circumference surface; the translucent surface is provided at the second end surface; the photodetector is located adjacent to and facing the first end surface.

8. The heating device as claimed in claim 1 , wherein the light guider is a reflector for reflecting the lights emitted by the electric heater to the optical rod.

9. The heating device as claimed in claim 1 , wherein the light guider comprises a bent transparent body, and a receiving surface and an emitting surface located at two ends of the bent transparent body respectively; the receiving surface faces the electric heater; the emitting surface faces the optical rod and is substantially perpendicular to a longitudinal axis of the optical rod.

10. The heating device as claimed in claim 1 , wherein the second end portion of the optical rod is located in the flow channel.

11. The heating device as claimed in claim 1 , further comprising a protective pipe sleeved onto the optical rod.

12. The heating device as claimed in claim 1 , wherein the flow channel is defined with a flowing direction along which the working fluid flows past the electric heater; the optical rod is a straight rod having a longitudinal axis substantially parallel to the flowing direction.

13. The heating device as claimed in claim 1 , wherein the housing has a top portion penetrated by the optical rod, and a bottom portion provided with an outlet communicated with the flow channel.

14. The heating device as claimed in claim 1 , further comprising an opaque pipe surrounding the electric heater and having a light transmissible portion; wherein the light guider faces the electric heater through the light transmissible portion of the opaque pipe.

15. The heating device as claimed in claim 14 , further comprising a transparent pipe located between the electric heater and the opaque pipe.

16. The heating device as claimed in claim 1 , further comprising a transparent pipe surrounding the electric heater; wherein the light guider faces the electric heater through the transparent pipe.

17. The heating device as claimed in claim 1 , wherein the first end portion is located outside the housing.

18. A method for protecting the heating device as claimed in claim 1 comprising steps of:
(a) measuring a temperature of the electric heater by using a controller receiving a detection signal of the photodetector; and
(b) turning off power supplied to the electric heater by the controller on a condition that the temperature of the electric heater measured in step (a) is higher than a predetermined threshold.

Assignees

• Mpi Corp

Inventors

• Krystad Helge Jacob
• Lee Yueh-Ying
• Chang Ying-Chiao

Classifications

• G05D23/27

  with sensing element responsive to radiation · CPC title

• G01J1/00

  Photometry, e.g. photographic exposure meter (spectrophotometry G01J3/00; specially adapted for radiation pyrometry G01J5/00 {; exposure meters built in cameras G03B17/06}) · CPC title

• F24H3/002

  using electric energy supply · CPC title

• F24H9/2071 Primary

  using electrical energy supply · CPC title

• F24H2250/14

  Lamps · CPC title