JPS6327436Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an electric heating element.

As shown in Figure 1, a spirally wound heating wire with a flat cross section (1A) is used as a heating element with high heat generation density and power distribution in the axial direction, but in order to further increase the heat generation density and give a higher output distribution ratio. , the width 1B tends to gradually increase, making spiral winding work difficult. To give an example of this numerically, 1B = 20mm, the length of the 1B width part is 50cm,
This is intended to be wound around a core with an outer diameter of 6 mm, and it is not hard to imagine that winding processing that satisfies the processing accuracy would be extremely difficult or impossible if the width 1B were further increased.

The present invention relates to a new electric heating element that replaces the spirally wound heating element, and an embodiment thereof will be illustrated and explained below. This example heating element is a heating element for a simulated fuel rod used in place of a nuclear fuel rod in nuclear reactor research. The temperature gradient of this simulated fuel rod is high in the center;
Since it is low on both sides, the width of the heating wire 1 is narrow in the center (1C) as shown in Figure 1, and gradually widens toward both sides, and at the outer end (1B) the heating wire 1 with a flat cross section (1A) is connected to a wire with a width of 1B. The length of the portion 2B is twisted to form a twisted body as shown in FIG. 2B, and the portion having a width other than 1B is spirally wound as shown in FIG. 2C to form a spiral body.

In other words, both sides with a low temperature gradient are simultaneously exposed to the heating wire 1.
Since the width of the body is wide at 1B, there is no need to sacrifice machining accuracy for spiral winding C, so we use twisted body B, which has high machining accuracy, and the center part is relatively narrow at 1C, making it easy to spiral wind. is intended to respond to high temperature gradients as a spiral wound C.

The present invention is characterized in that both sides are made into a twisted body B, and in the case of spiral winding and the heating element 1.
Comparing with the case where the fuel is used as it is in the form of a band, the temperature gradient is unevenly distributed on both sides of the flat part of the heating element 1 when it is used as it is in the form of a band. In the entire rod, a uniform temperature gradient is generated over its entire circumference and length.

By forming the twisted body B, it becomes easier to absorb the difference in thermal expansion.

As explained above, twisting is easy.

As mentioned above, it has many advantages compared to band-shaped and spiral-shaped heating elements.

[Brief explanation of drawings]

Fig. 1 is a front view of the heating element as it is in the form of a band (the width is the original size, but the length is scaled down). Fig. 2 is a partially enlarged view of the twisted body and spiral body. Explanation of symbols, 1...Heating wire, B...Twisted body, C...
...Spiral.

Claims (1)

[Scope of utility model registration request] A heating element characterized in that the width of a heating wire with a flat cross section is narrow at the center and gradually wider toward both sides, with the central part formed into a spiral body and both sides formed into twisted bodies.