WO2021227126A1 - Heating body, and vacuum furnace with multi-region temperature control - Google Patents

Abstract

Disclosed are a heating body and a vacuum furnace with multi-region temperature control. In the heating body, first ends of a plurality of first heating sheets in a first heating unit are connected to a first connecting sheet in parallel, and second ends thereof are connected to a first corner connecting sheet in parallel; first ends of a plurality of second heating sheets in a second heating unit are connected to the first corner connecting sheet in parallel, and second ends thereof are connected to a second corner connecting sheet in parallel; and first ends of a plurality of third heating sheets in a third heating unit are connected to the second corner connecting sheet in parallel, and second ends thereof are connected to a second connecting sheet in parallel. A first electrode bar is fixed to the first connecting sheet, and the first electrode bar is configured to be connected to a first terminal of a single-phase transformer; and a second electrode bar is fixed to the second connecting sheet, and the second electrode bar is configured to be connected to a second terminal of the single-phase transformer. A radial cross section of the heating body is U-shaped, and the first connecting sheet and the second connecting sheet are not coplanar. The present invention can reduce the difficulty of regulating the temperature of a vacuum furnace and improve the temperature uniformity of the vacuum furnace.

Description

Heating body and multi-zone temperature control vacuum furnace

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 202010385636.8, and the invention title is "a heating body and a vacuum furnace with multi-zone temperature control" on May 9, 2020, the entire content of which is incorporated by reference Incorporated in this application.

Technical field

The invention relates to the field of temperature control, in particular to a heating body and a vacuum furnace with multi-zone temperature control.

Background technique

The uniformity of temperature distribution is a very important indicator for testing the performance of the vacuum sintering furnace. The smaller the temperature deviation in the furnace and the front, middle, rear, upper and lower areas of the furnace, the better the size and performance control of the processed material after sintering. The higher the yield, the lower the production cost. Affecting the uniformity of temperature distribution usually includes the following factors: (1) It is related to design. For example, the size of the furnace body, the larger the volume, the worse the uniformity. The position of the connection interface of the furnace body, such as the large heat loss at the pump port, etc.; or there is a large heat loss from the cooler somewhere, etc. (2) The uniformity of the insulation of the insulation material itself. The uniformity of imported ones is much better than that of domestic ones, and domestic ones are generally not used in furnaces that require higher dimensions like the MIM industry. (3) Heating uniformity. The resistance of the heating body itself also varies in uniformity, and the same material of the graphite part may not necessarily have the same resistivity. (4) The influence of airflow in different areas. If the hot air flows upward, the temperature of the upper part will generally be higher than the temperature of the lower part.

Most of the vacuum furnaces in the prior art are zone 1 heating. When there is a large difference between the front and back or the upper and lower temperatures, the resistance value is adjusted by adjusting the size of the heating body, and then the imported heat preservation material is used for heat preservation to reduce the vacuum furnace The temperature difference of each zone. Therefore, it is not easy to adjust the temperature of the existing vacuum furnace temperature control method, especially for the occasions where the temperature is difficult to control and the deviation is large such as the large furnace type and the convection of the pressurized atmosphere, the temperature is more difficult to adjust, resulting in poor temperature uniformity of the vacuum furnace.

Summary of the invention

The purpose of the present invention is to provide a heating body and a vacuum furnace with multi-zone temperature control, so as to reduce the difficulty of temperature adjustment of the vacuum furnace and improve the temperature uniformity of the vacuum furnace.

To achieve the above objective, the technical solution of the present invention is: a heating body, comprising: a first connecting piece, a first heating unit, a first corner connecting piece, a second heating unit, a second corner connecting piece, and a third heating unit , The second connecting piece, the first electrode rod and the second electrode rod;

The first heating unit includes a plurality of first heating sheets, the first ends of the plurality of first heating sheets are connected in parallel to the first connecting sheet, and the second ends of the plurality of first heating sheets are connected in parallel To the first corner connecting piece;

The second heating unit includes a plurality of second heating plates, the first ends of the plurality of second heating plates are connected in parallel to the first corner connecting plate, and the second ends of the plurality of second heating plates are connected in parallel Connected to the second corner connecting piece;

The third heating unit includes a plurality of third heating plates, the first ends of the plurality of third heating plates are connected in parallel to the second corner connecting plate, and the second ends of the plurality of third heating plates are connected in parallel Connected to the second connecting piece;

The first electrode rod is fixed on the first connecting piece, and the first electrode rod is used to connect with the first terminal of the single-phase transformer; the second electrode rod is fixed on the second connecting piece, so The second electrode rod is used to connect with the second terminal of the single-phase transformer; the radial cross section of the heating body is U-shaped, and the first connecting piece and the second connecting piece are located in the U-shaped Different sidewalls.

Optionally, the first heating plate is a straight heating plate, a plate heating plate or a frame heating plate.

Optionally, the second heating plate is a straight type heating plate, a plate type heating plate or a frame type heating plate.

Optionally, the third heating plate is a straight heating plate, a plate type heating plate or a frame type heating plate.

Optionally, the first ends of the plurality of first heating plates are connected to the first connecting plate through bolts and nuts, and the second ends of the plurality of first heating plates are connected to the first corner through bolts and nuts. Connecting piece; the first ends of the plurality of second heating pieces are connected to the first corner connecting piece through bolts and nuts, and the second ends of the plurality of second heating pieces are connected to the second corner through bolts and nuts Connecting piece; the first ends of the plurality of third heating pieces are connected to the second corner connecting piece through bolts and nuts, and the second ends of the plurality of third heating pieces are connected to the second connection through bolts and nuts piece;

The first electrode rod is fixed on the first connecting piece by a nut; the second electrode rod is fixed on the second connecting piece by a nut.

The present invention also provides a multi-zone temperature-controlled vacuum furnace. The multi-zone temperature-controlled vacuum furnace adopts the above-mentioned heating body. The multi-zone temperature-controlled vacuum furnace includes a sealed box, a heating device and a heat insulation cylinder, The heating device is wrapped on the outside of the sealed box, and the heat insulation cylinder is wrapped on the outside of the heating device;

The heating device includes a plurality of heating body groups, and the plurality of heating body groups are uniformly distributed outside the sealed box along the axial direction of the sealed box; each heating body group includes a plurality of heating bodies, and a plurality of heating bodies Evenly surround the outside of the sealed box;

Each heating body corresponds to a power controller, and the output power of the single-phase transformer corresponding to the heating body is adjusted by the power controller, thereby adjusting the heating temperature of the sealed box area corresponding to the heating body.

Optionally, the number of heating bodies in each heating body group is 2 or 4.

Optionally, the heating device is cylindrical or prismatic;

When the heating device is cylindrical, the radial cross-sections of the first corner connecting piece, the second corner connecting piece, the first heating piece, the second heating piece and the third heating piece of the heating body are all arc-shaped;

When the heating device is prismatic, the first corner connecting piece and the second corner connecting piece of the heating body are both located on the side edge of the sealed box; the first heating piece and the second heating Both the sheet and the third heating sheet are located on the side of the sealed box.

Optionally, it also includes: multiple thermocouples and multiple PID controllers; multiple thermocouples, multiple PID controllers, and multiple power controllers all correspond to multiple heating bodies one-to-one; for the kth heating body , The thermocouple is connected to the PV input end of the PID controller, and is used to transmit the temperature measurement value of the sealed box area corresponding to the kth heating body to the PID controller; The control output terminal is connected to the control input terminal of the power controller, and the output terminal of the power controller is connected to the input terminal of the single-phase transformer corresponding to the k-th heating body, and is used to adjust the power of the single-phase transformer. Output power to adjust the heating temperature of the k-th heating body.

Compared with the prior art, the present invention has the advantages that the multi-zone temperature control mode of the vacuum furnace of the present invention compensates for the defect of temperature deviation of the insulation material itself, and reduces the requirements for the insulation material. Moreover, the temperature adjustment method is simple and easy to adjust, and the temperature uniformity can be achieved for larger furnace types; for the furnace of the same volume, the temperature difference in different areas is also greatly reduced. In addition, the heating rate of the vacuum furnace is increased, the heating process time is shortened, and the cost is saved. It also improves the yield rate of the full furnace, reduces the cost, and solves the problem of substandard product size, appearance and density caused by temperature deviation in some areas of the vacuum furnace.

Attached drawings

The present invention will be further explained below in conjunction with the drawings:

Figure 1 is a schematic diagram of the structure of the heating body of the present invention;

Figure 2 is a schematic view of the tile of the heating body of the present invention;

Figure 3 is a cross-sectional view of the vacuum furnace of the present invention;

Figure 4 is a first side view of the heating device in the vacuum furnace of the present invention;

Figure 5 is a second side view of the heating device in the vacuum furnace of the present invention;

Figure 6 is a schematic circuit diagram of the heating device in the vacuum furnace of the present invention;

Figure 7 is a comparison diagram of equivalent circuits of the electrode rods of the heating body at different positions;

FIG. 8 is a schematic diagram of the heating device of specific embodiment 1 of the present invention;

Fig. 9 is a schematic diagram of the heating body in the heating device of the specific embodiment 1 of the present invention;

Figure 10 is an expanded view of the heating body in the heating device of the specific embodiment 1 of the present invention;

Figure 11 is a schematic diagram of a heating device according to Embodiment 2 of the present invention;

Fig. 12 is a schematic diagram of the heating body in the heating device of the specific embodiment 2 of the present invention;

Figure 13 is an exploded view of the heating body in the heating device of the specific embodiment 2 of the present invention;

Figure 14 is a schematic diagram of a heating device according to Embodiment 3 of the present invention;

15 is a schematic diagram of the heating body in the heating device of the specific embodiment 3 of the present invention;

Figure 16 is an expanded view of the heating body in the heating device of the specific embodiment 3 of the present invention;

Fig. 17 is a schematic diagram of a heating device according to specific embodiment 4 of the present invention;

18 is a schematic diagram of the heating body in the heating device of the specific embodiment 4 of the present invention;

Figure 19 is an expanded view of the heating body in the heating device of the specific embodiment 4 of the present invention;

Figure 20 is a schematic diagram of a heating device according to Embodiment 5 of the present invention;

21 is a schematic diagram of the heating body in the heating device of the specific embodiment 5 of the present invention;

Figure 22 is an expanded view of the heating body in the heating device of the specific embodiment 5 of the present invention;

Figure 23 is a first schematic diagram of the heating area in the cross section of the heating device of the present invention;

Fig. 24 is a second schematic diagram of the heating area in the cross section of the heating device of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of the structure of the heating body of the present invention. As shown in Figure 1, the heating body of the present invention includes the following structures: a first connecting piece 1, a first heating unit, a first corner connecting piece 3, a second heating unit, a second corner connecting piece 5, a third heating unit, and a Two connecting pieces 7, a first electrode rod 8 and a second electrode rod 9;

The first heating unit includes a plurality of first heating plates (2-1 and 2-2 in the figure are two first heating plates), and the first ends of the plurality of first heating plates are connected in parallel to the first heating plate. A connecting piece 1, the second ends of a plurality of the first heating pieces are connected to the first corner connecting piece 3 in parallel.

The second heating unit includes a plurality of second heating plates (4-1 and 4-2 in the figure are two second heating plates), and the first ends of the plurality of second heating plates are connected in parallel to the first heating plate. A corner connecting piece 3, the second ends of a plurality of second heating fins are connected in parallel to the second corner connecting piece 5;

The third heating unit includes a plurality of third heating fins (6-1 and 6-2 in the figure are two third heating fins), and the first ends of the plurality of third heating fins are connected in parallel to the first end Two-corner connecting piece 5, the second ends of a plurality of the third heating pieces are connected in parallel to the second connecting piece 7;

The first electrode rod 8 is fixed on the first connecting piece 1, the first electrode rod 8 is used to connect with the first terminal of a single-phase transformer; the second electrode rod 9 is fixed on the first terminal On the second connecting piece 7, the second electrode rod 9 is used to connect with the second terminal of the single-phase transformer. The radial cross section of the heating body is U-shaped, and the first connecting piece 1 and the second connecting piece 7 are not coplanar. The U-shape in the present invention refers to a shape composed of an arc, a semicircle, and a half polygon with a recessed area.

In the present invention, the first heating plate, the second heating plate and the third heating plate can all be straight type heating plates, plate type heating plates or frame type heating plates. Straight heating plate refers to the shape of the heating plate. At this time, the two ends of the straight bar are the two connecting ends of the heating plate, which are connected with the connecting plate or the corner connecting plate. Plate-shaped heating plate means that the shape of the heating plate is plate-shaped, such as a flat plate shape or an arc-shaped plate. At this time, the two parallel straight sides of the plate shape are the two connecting ends of the heating plate. Frame type heating plate refers to the shape of the heating plate is a hollow frame shape. At this time, the two straight sides of the frame shape parallel to each other are the two connecting ends of the heating plate, and the frame edge between the two straight sides can be straight. Type, S type or other shapes.

In the above heating body of the present invention, the first end of each first heating plate is connected to the first connecting plate 1 through a bolt and nut, and the second end of each first heating plate is connected to the first connecting plate through a bolt and nut. The first corner connecting piece 3; the first end of each second heating piece is connected to the first corner connecting piece 3 through a bolt and nut, and the second ends of a plurality of second heating pieces are connected to the first corner connecting piece 3 through a bolt and nut The second corner connecting piece 5; the first ends of the plurality of third heating pieces are connected to the second corner connecting piece 5 by bolts and nuts 11, and the second ends of the plurality of third heating pieces are connected by bolts The nut is connected to the second connecting piece 7. The first electrode rod 8 is fixed on the first connecting piece 1 by a corresponding nut 10; the second electrode rod 9 is fixed on the second connecting piece 7 by a corresponding nut (not shown in the figure) .

Figure 2 is a schematic view of the tile of the heating body of the present invention. As shown in Figure 2, the first electrode rod and the second electrode rod in the heating body of the present invention are respectively connected to the two terminals of the transformer, thus forming a single-phase circuit. The current enters from the A1 end and flows through the first electrode rod, the first heating plate 2-1, the first heating plate 2-2, the corner connecting plate 3, the second heating plate 4-1, the second heating plate 4-2, The corner connecting piece 5, the third heating piece 6-1, the third heating piece 6-2, and the second electrode rod 9, return to the B1 end. The entire heating body is equivalent to three heating units (the first heating unit, the second heating unit, and the third heating unit) in series. Each heating unit is composed of multiple resistors in parallel. The first heating unit includes two first heating units. Taking the heating plate as an example, the first heating unit is connected in parallel by two resistors, the first heating plate 2-1 and the first heating plate 2-2, or more than two first heating plates are connected in parallel.

Each heating body of the present invention corresponds to a heating area, and the corresponding heating temperature of the heating body can be adjusted by adjusting the output power of the transformer corresponding to the heating body.

Based on the above heating body, the present invention also provides a multi-zone temperature-controlled vacuum furnace. FIG. 3 is a cross-sectional view of the vacuum furnace of the present invention. As shown in FIG. 3, the vacuum furnace of the present invention includes: a sealed box 31, a heating device 32, an insulating cylinder 33 and a sealed box guide rail 35. The heating device 32 is wrapped on the outside of the sealed box 31, and the heat insulation cylinder 33 is wrapped on the outside of the heating device 32. The vacuum furnace of the present invention also includes a plurality of thermocouples 34 and a plurality of PID controllers.

Fig. 4 is a first side view of the heating device in the vacuum furnace of the present invention, and Fig. 5 is a second side view of the heating device in the vacuum furnace of the present invention. As shown in FIG. 4 and FIG. 5, the heating device 32 of the present invention includes a plurality of heating body groups, and the plurality of heating body groups are uniformly distributed outside the sealed box 31 along the axial direction of the sealed box 31. The figure includes 3 A heating body group. Each heating body group includes a plurality of heating bodies as shown in FIG. In the figure, the first heating body group includes two heating bodies, the two electrode rods of the first heating body are A1 and B1 respectively, and the two electrode rods of the second heating body are A4 and B4 respectively; the second heating body The body group includes two heating bodies, the two electrode rods of the first heating body are A2 and B2 respectively, the two electrode rods of the second heating body are A5 and B5 respectively; the third heating body group includes two heating bodies The two electrode rods of the first heating body are A3 and B3 respectively, and the two electrode rods of the second heating body are A6 and B6 respectively. Each heating body corresponds to a power controller, and the output power of the single-phase transformer corresponding to the heating body is adjusted by the power controller, thereby adjusting the heating temperature of the sealed box area corresponding to the heating body.

In the vacuum furnace of the present invention, multiple thermocouples, multiple PID controllers, and multiple power controllers are in one-to-one correspondence with multiple heating bodies. Figure 6 is a schematic circuit diagram of the heating device in the vacuum furnace of the present invention. As shown in Figure 6, for the kth heating body, the thermocouple is connected to the PV input end of the PID controller for connecting the kth The temperature measurement value of the sealed box area corresponding to each heating body is transmitted to the PID controller; the control output terminal of the PID controller is connected with the control input terminal of the power controller, and the output terminal of the power controller is connected with the control input terminal of the power controller. The input end of the single-phase transformer corresponding to the k-th heating body is connected to adjust the output power of the single-phase transformer, thereby adjusting the heating temperature of the k-th heating body.

In the present invention, the heating device 31 is cylindrical or prismatic. When the heating device 31 is cylindrical, the radial cross-sections of the first corner connecting piece, the second corner connecting piece, the first heating piece, the second heating piece and the third heating piece of the heating body are all arc-shaped When the heating device 31 is prismatic, the first corner connecting piece and the second corner connecting piece of the heating body are both located on the side edge of the sealed box; the first heating piece, the first Both the second heating plate and the third heating plate are located on the side of the sealed box.

In the heating body of the present invention, the first electrode rod and the second electrode rod are located on different side walls of the U-shape, that is, on different sides. Compared with the heating body in which the first electrode rod and the second electrode rod are on the same side, this The invented heating body has great advantages. The heating body with the electrodes on the same side has the following defects:

The metal electrode rod connected to the electrode rod is filled with cooling water. During the heating process of the heating body, the temperature at the electrode rod is relatively low. The heat on the side connected to the electrode rod will quickly transfer to the electrode rod, resulting in the temperature of the water passing side. The heat dissipation is faster, which will cause the temperature of the side connected to the electrode rod and the side not connected to the electrode rod to be different, resulting in a deviation in the size of the products on both sides. To solve this problem, it is necessary to adjust the resistance distribution of the heating body so that the resistance value of the heating body on the electrode side is greater than that of the other side, and the specific value can be obtained through continuous experiments. The process is extremely complicated and cumbersome. In the process of heating and heat preservation, the heat lost to the electrode rod side is different. This leads to the fact that although the resistance value on both sides of the heating body can be adjusted to achieve a relatively uniform temperature on both sides during heat preservation, the temperature rises At this time, the temperature deviation on both sides is relatively large, so that the product size on both sides will also have a large deviation.

The heating body structure on both sides of the electrode rod has the following advantages:

Since the electrode rods are on both sides, when the heating body dissipates heat, it will conduct to both sides at the same time, so that the temperature on both sides is relatively uniform, and the resistance value of the heating body on both sides only needs to be the same, which is easy to achieve. In addition, the heating body structure on both sides of the electrode rods saves materials and saves costs.

Fig. 7 is a comparison diagram of equivalent circuits of the electrode rods of the heating body at different positions. With reference to Fig. 7, it is assumed that there are two heating bodies with electrode rods on both sides and electrode rods on the same side, and the resistance value of each heating piece of the heating body of each structure is the same. Part (a) in Fig. 7 is the equivalent circuit of the heating body with the electrode rods on both sides, and part (b) in Fig. 7 is the equivalent circuit of the heating body with the electrode rods on the same side. Assuming that the resistance value of the half heating plate in part (b) of Fig. 7 is 20Ω, the resistance value of one heating plate is 10Ω, then the total resistance value of the heating body in a single area is 10×6=60Ω.

The heating body shown in part (a) of Fig. 7, that is, the heating body of the present invention, should make the total resistance value of a single zone also 60Ω. Assuming the resistance value of the half heating body is R, the resistance value of one heating chip is R/2, then the total resistance value of a single area=R/2÷2×3=60, and it is obtained that R=80Ω, that is, the resistance value of the half heating plate is 80Ω, and the resistance value of one heating plate is 40Ω.

It can be concluded that in the case of ensuring the same single-zone resistance value for the two structures, the resistance value of the single-piece heating plate in the heating body structure on both sides of the electrode rods is larger. In the case that the heating plates of the two structures use the same material and have the same shape, according to R=ρL/S, the S value of each heating plate of the heating body structure with the electrode rods on both sides is smaller, and S is the heating plate The cross-sectional area indicates that the heating plate of the heating body structure with the electrode rods on both sides is thinner than the heating plate of the heating body structure with the electrode rods on the same side, that is, it saves more material.

Several specific examples are provided below to further illustrate the solution of the present invention.

Specific Example 1

Fig. 8 is a schematic diagram of the heating device of specific embodiment 1 of the present invention, Fig. 9 is a schematic diagram of a single heating body in the heating device of specific embodiment 1 of the present invention, and Fig. 10 is a single heating body of the heating device of specific embodiment 1 of the present invention Expanded view. As shown in FIGS. 8-10, the heating plate of the heating body in this embodiment is a straight bar type. Each of the first heating unit, the second heating unit, and the third heating unit includes 4 straight heating sheets. In this embodiment, the heating temperature control of 6 zones can be realized.

Specific Example 2

Fig. 11 is a schematic diagram of the heating device of specific embodiment 2 of the present invention, Fig. 12 is a schematic diagram of a single heating body in the heating device of specific embodiment 2 of the present invention, and Fig. 13 is a single heating body of the heating device of specific embodiment 2 of the present invention Expanded view. As shown in FIGS. 11-13, the heating plate of the heating body in this embodiment is plate-shaped, and the first heating unit, the second heating unit, and the third heating unit each include two plate-shaped heating plates. In this embodiment, the heating temperature control of 6 zones can be realized.

Specific Example 3

14 is a schematic diagram of a heating device in specific embodiment 3 of the present invention, FIG. 15 is a schematic diagram of a single heating body in the heating device in specific embodiment 3 of the present invention, and FIG. 16 is a single heating body in the heating device in specific embodiment 3 of the present invention Expanded view. As shown in FIGS. 14-16, the heating plate of the heating body in this embodiment is frame-shaped, and the first heating unit, the second heating unit, and the third heating unit each include two frame-shaped heating plates. In this embodiment, the heating temperature control of 6 zones can be realized.

Specific Example 4

Fig. 17 is a schematic diagram of a heating device in specific embodiment 4 of the present invention, Fig. 18 is a schematic diagram of a single heating body in the heating device of specific embodiment 4 of the present invention, and Fig. 19 is a single heating body in the heating device of specific embodiment 4 of the present invention Expanded view. In this embodiment, the heating plate of the heating body is frame-shaped, and the first heating unit, the second heating unit and the third heating unit each include two frame-shaped heating plates, and each frame-shaped heating plate is formed by a combination of three rectangles. The frame structure. In this embodiment, the heating temperature control of 6 zones can be realized. Compared with the frame type in specific embodiment 3, the heating effect of the heating device in this embodiment is more uniform.

Specific Example 5

Fig. 20 is a schematic diagram of a heating device of specific embodiment 5 of the present invention, Fig. 21 is a schematic diagram of a single heating body in the heating device of specific embodiment 5 of the present invention, and Fig. 22 is a single heating body of the heating device of specific embodiment 5 of the present invention Expanded view. As shown in FIGS. 20-22, the entire heating device in this embodiment is arranged in a cylindrical shape. The heating plate of the heating body in this embodiment is frame-shaped. The difference from other embodiments is that the electrode rods in this embodiment are located on the same side and include 3 groups of heating body groups in the axial direction of the sealed box, and in the circumferential direction of the sealed box, Each heating body group is surrounded by four heating bodies to wrap the sealed box. In this embodiment, the area controlled by each heating body is relatively small, and the entire heating device realizes the heating temperature control of 12 areas. According to actual needs, the heating device can also be arranged in other shapes, for example, in a prismatic shape. The structure of the heating device shown in this embodiment is more effective for temperature control and heating for furnaces with larger diameters.

Fig. 23 is a first schematic diagram of the heating area in the cross section of the heating device of the present invention. As shown in Figure 23, when the furnace diameter is relatively large and the temperature is required to be more uniform, the temperature control area on the cross section of the sealed box can be designed as shown in Figure 23, through the upper left, middle left, lower left, and upper right , Right middle and bottom right six areas to control the temperature, extending into the heating area of 6, 12, 18, 24...6 multiples in the length direction.

Fig. 24 is a second schematic diagram of the heating area in the cross section of the heating device of the present invention. As shown in Figure 24, when the furnace diameter is larger and the temperature is required to be more uniform, the temperature control area on the cross section can be designed into the structure shown in Figure 24, through left 1, left 2, left 3, and left 4. Eight areas on the right 1, right 2, right 3, and right 4 are used to control the temperature, and the heating area is expanded to a multiple of 8, 16, 24, 32...8 in the length direction.

The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.

The above embodiments are provided only for the purpose of describing the present invention, and are not intended to limit the scope of the present invention. The scope of the invention is defined by the appended claims. Various equivalent replacements and modifications made without departing from the spirit and principle of the present invention should all fall within the scope of the present invention.

Claims (9)

1. A heating body, characterized by comprising: a first connecting piece, a first heating unit, a first corner connecting piece, a second heating unit, a second corner connecting piece, a third heating unit, a second connecting piece, a first Electrode rod and second electrode rod;

   The first heating unit includes a plurality of first heating sheets, the first ends of the plurality of first heating sheets are connected in parallel to the first connecting sheet, and the second ends of the plurality of first heating sheets are connected in parallel To the first corner connecting piece;

   The second heating unit includes a plurality of second heating plates, the first ends of the plurality of second heating plates are connected in parallel to the first corner connecting plate, and the second ends of the plurality of second heating plates are connected in parallel Connected to the second corner connecting piece;

   The third heating unit includes a plurality of third heating plates, the first ends of the plurality of third heating plates are connected in parallel to the second corner connecting plate, and the second ends of the plurality of third heating plates are connected in parallel Connected to the second connecting piece;

   The first electrode rod is fixed on the first connecting piece, and the first electrode rod is used to connect with the first terminal of the single-phase transformer; the second electrode rod is fixed on the second connecting piece, so The second electrode rod is used to connect with the second terminal of the single-phase transformer; the radial cross section of the heating body is U-shaped, and the first connecting piece and the second connecting piece are located in the U-shaped Different sidewalls.
2. The heating body according to claim 1, wherein the first heating plate is a straight heating plate, a plate heating plate or a frame heating plate.
3. The heating body according to claim 1, wherein the second heating plate is a straight heating plate, a plate heating plate or a frame heating plate.
4. The heating body according to claim 1, wherein the third heating plate is a straight heating plate, a plate heating plate or a frame heating plate.
5. The heating body according to claim 1, wherein the first ends of the plurality of first heating plates are connected to the first connecting plate by bolts and nuts, and the second ends of the plurality of first heating plates Connected to the first corner connecting piece by bolts and nuts; first ends of a plurality of second heating plates are connected to the first corner connecting piece by bolts and nuts, and second ends of a plurality of second heating plates Connected to the second corner connecting piece by bolts and nuts; the first ends of the plurality of third heating plates are connected to the second corner connecting piece by bolts and nuts, and the second ends of the plurality of third heating plates Connected to the second connecting piece by bolts and nuts;

   The first electrode rod is fixed on the first connecting piece by a nut; the second electrode rod is fixed on the second connecting piece by a nut.
6. A vacuum furnace with multi-zone temperature control, characterized in that the vacuum furnace with multi-zone temperature control adopts the heating body according to any one of claims 1 to 5, and the vacuum furnace with multi-zone temperature control includes: A box, a heating device and a heat-insulating cylinder, the heating device is wrapped around the outside of the sealed box, and the heat-insulating cylinder is wrapped around the outside of the heating device;

   The heating device includes a plurality of heating body groups, and the plurality of heating body groups are uniformly distributed outside the sealed box along the axial direction of the sealed box; each heating body group includes a plurality of heating bodies, and a plurality of heating bodies Evenly surround the outside of the sealed box;

   Each heating body corresponds to a power controller, and the output power of the single-phase transformer corresponding to the heating body is adjusted by the power controller, thereby adjusting the heating temperature of the sealed box area corresponding to the heating body.
7. The vacuum furnace with multi-zone temperature control according to claim 6, wherein the number of heating bodies in each heating body group is 2 or 4.
8. The vacuum furnace with multi-zone temperature control according to claim 6, wherein the heating device is cylindrical or prismatic;

   When the heating device is cylindrical, the radial cross-sections of the first corner connecting piece, the second corner connecting piece, the first heating piece, the second heating piece and the third heating piece of the heating body are all arc-shaped;

   When the heating device is prismatic, the first corner connecting piece and the second corner connecting piece of the heating body are both located on the side edge of the sealed box; the first heating piece and the second heating Both the sheet and the third heating sheet are located on the side of the sealed box.
9. The multi-zone temperature-controlled vacuum furnace according to claim 6, characterized in that it further comprises: multiple thermocouples and multiple PID controllers; multiple thermocouples, multiple PID controllers and multiple power controllers. One-to-one correspondence with multiple heating bodies; for the kth heating body, the thermocouple is connected to the PV input end of the PID controller for measuring the temperature of the sealed box area corresponding to the kth heating body The value is transmitted to the PID controller; the control output of the PID controller is connected to the control input of the power controller, and the output of the power controller is single-phase corresponding to the k-th heating body The input end of the transformer is connected to adjust the output power of the single-phase transformer, and further adjust the heating temperature of the k-th heating body.

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