A temperature control system for ensuring temperature uniformity in a hot isostatic pressing working zone

Abstract

This invention discloses a temperature control system for ensuring temperature uniformity in the working zone of a hot isostatic press (HIP), belonging to the technical field of temperature uniformity control in HIP machines. It includes a working cylinder with a working chamber inside, and an inner cylinder inside the working chamber. A double-layer molybdenum-lanthanum insulation cylinder and a flow guide cylinder are sequentially arranged from the inside to the outside between the inner cylinder and the working chamber. Water-cooling channels are arranged around the side walls of the working cylinder. A circulating pump mechanism is located at the bottom of the inner cylinder. A first flow channel is provided between the working chamber and the double-layer molybdenum-lanthanum insulation cylinder, and a second flow channel is provided between the double-layer molybdenum-lanthanum insulation cylinder and the flow guide cylinder. A third flow channel is formed between the flow guide cylinder and the inner wall of the working cylinder. This invention utilizes the double-layer molybdenum-lanthanum insulation cylinder and the flow guide cylinder to more effectively guide the gas path, directing the high-temperature gas accumulated at the top of the working chamber to the outer cooling layer, effectively alleviating the problem of high-temperature gas accumulation at the top of the hot zone, and has good practicality.

Description

Technical Field

[0001] This invention belongs to the technical field of temperature uniformity control of hot isostatic presses, specifically relating to a temperature control system that ensures the temperature uniformity of the hot isostatic pressing working area. Background Technology

[0002] Hot isostatic pressing (HIP) is an advanced piece of equipment used in the hot isostatic pressing process. It involves applying isostatic pressure in all directions to powder or compacted sintered blanks (or parts) within a high-temperature, high-pressure sealed container, using nitrogen (or argon) as the medium, to form a high-density blank (or part). HIP is an indispensable tool for the production of high-performance materials and the development of new materials, and is a key piece of equipment for densifying aerospace castings.

[0003] Currently, when using hot isostatic pressing (HIP) to process materials under high temperature and pressure, the temperature uniformity of the HIP's working zone is crucial to the performance of the processed parts. This is especially true for large and extra-large HIP equipment, where the working zone is large, and temperature uniformity is critical for large-scale production. However, during HIP processing, due to the phenomenon of gas convection heat transfer, the temperature in the working zone naturally accumulates from the bottom to the top, resulting in poor temperature uniformity in the hot zone. Summary of the Invention

[0004] The purpose of this invention is to provide a temperature control system that ensures temperature uniformity in the hot isostatic pressing working zone, thereby solving the aforementioned problems.

[0005] This invention is mainly achieved through the following technical solutions: A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone includes a working cylinder, a working chamber inside the working cylinder, an inner cylinder inside the working chamber, and a double-layer molybdenum-lanthanum insulation cylinder and a flow guide cylinder arranged sequentially from the inside to the outside between the inner cylinder and the working chamber; water cooling channels are arranged around the side wall of the working cylinder; a circulation pump mechanism is arranged at the bottom inside the inner cylinder, and a loading platform is arranged at the top of the circulation pump mechanism; A first flow channel is provided between the inner cylinder and the double-layer molybdenum-lanthanum insulation cylinder, and a second flow channel is provided between the double-layer molybdenum-lanthanum insulation cylinder and the guide cylinder. A third flow channel is formed between the guide cylinder and the inner wall of the working cylinder. A vent hole is provided at the top of the working chamber corresponding to the first flow channel, and the top of the first flow channel has an arc-shaped structure to allow the high-temperature gas accumulated at the top of the inner cylinder to flow from top to bottom within the first flow channel. The bottom of the double-layer molybdenum-lanthanum insulation cylinder is connected to the second flow channel, allowing the high-temperature gas to flow from bottom to top within the second flow channel. The top of the guide cylinder is connected to the working cylinder. The circulation pump mechanism is used to draw the high-temperature gas from the side wall of the working cylinder from top to bottom through the third flow channel and into the inner cylinder, achieving gas circulation. A heating mechanism is provided at the circulation pump mechanism to heat the circulating airflow before pouring it into the inner cylinder to replenish the heat lost at the bottom.

[0006] To better realize the present invention, the bottom of the double-layer molybdenum-lanthanum insulation cylinder and the flow guide cylinder are respectively provided with a heat insulation screen base and a flow guide cylinder base. The heat insulation screen base is installed on the flow guide cylinder base so as to surround the double-layer molybdenum-lanthanum insulation cylinder inside the flow guide cylinder. The heat insulation screen base has a peripheral opening for guiding high-temperature gas into the second flow channel.

[0007] To better realize the present invention, the peripheral sidewall of the double-layer molybdenum-lanthanum insulation cylinder is further provided with a plurality of vent holes from top to bottom along the radial direction to guide the convective gas to dissipate outward and prevent heat accumulation at the top; the vent holes are connected to the openings on the peripheral side of the heat insulation screen chassis to merge with the airflow guided from the first drainage channel into the second drainage channel.

[0008] To better realize the present invention, the double-layer molybdenum-lanthanum insulation cylinder further comprises, from the inside to the outside, a molybdenum-lanthanum inner cylinder, an inner insulation layer, a molybdenum-lanthanum outer cylinder, an outer insulation layer, and a stainless steel outer cylinder. The peripheral sidewalls of the molybdenum-lanthanum inner cylinder and the molybdenum-lanthanum outer cylinder are respectively provided with vent holes in the radial direction. The outer insulation layer and the stainless steel outer cylinder, as well as the inner insulation layer and the molybdenum-lanthanum outer cylinder, are respectively spaced apart to guide the gas in the vent holes into the openings on the periphery of the heat insulation screen chassis.

[0009] To better realize the present invention, the inner insulation layer and the outer insulation layer are further prepared from ceramic fiber blankets.

[0010] To better realize the present invention, the top of the guide tube is further provided with a plurality of through holes arranged in an array to guide the airflow from the bottom to the top of the guide tube. Preferably, the top of the guide tube is provided with a plurality of through holes arranged in a ring array.

[0011] The beneficial effects of this invention are as follows: (1) The double-layer molybdenum-lanthanum insulation cylinder and circulating pump mechanism of the present invention accelerate the rapid introduction of the high-temperature gas accumulated at the top of the inner cylinder into the first, second, and third drainage channels in sequence, and finally, after cooling control, it is introduced into the inner cylinder for recycling. During the circulation and extraction process, the high-temperature gas accumulated at the top is guided back from top to bottom around the periphery of the working cylinder, which can ensure the overall temperature stability and reduce heat loss, and has good practicality.

[0012] (2) The present invention uses the air vents arranged radially on the periphery of the double-layer molybdenum lanthanum insulation cylinder and the openings on the periphery of the heat insulation screen base to guide the high temperature gas into the second flow channel, while reducing the heating effect of the high temperature gas on the periphery and scattering the temperature of the high temperature gas radially, thereby further improving the overall temperature uniformity and having good practicality.

[0013] (3) This invention utilizes a double-layer molybdenum-lanthanum insulation cylinder and a guide cylinder to more effectively guide the gas path, directing the high-temperature gas accumulated at the top of the working chamber to the third flow channel for cooling. This effectively alleviates the problem of high-temperature gas accumulation at the top of the hot zone. This invention innovatively applies rapid cooling technology to the field of temperature uniformity control. A fan device is installed at the bottom of the hot zone, rotating slowly during the heating process to fully mix the gas in the hot zone. While losing heat, it works in conjunction with the heat compensation of the heating zone at the bottom of the hot zone (lower end of the inner cylinder) to form a dynamic balance of heat, effectively improving the temperature uniformity of the hot zone. Specifically, this invention causes the high-temperature gas to accumulate upwards from the heating furnace to the top of the inner cylinder. Under the action of gas pressure, it flows downwards along the double-layer molybdenum-lanthanum insulation cylinder, enters the guide cylinder from the bottom of the double-layer molybdenum-lanthanum insulation cylinder, and then flows upwards along the guide cylinder to the outer layer of the hot zone. Under the action of the outer layer water cooling channel, it is cooled and enters the gas circulation. Attached Figure Description

[0014] Figure 1 A schematic diagram of the temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to the present invention; Figure 2 This is a schematic diagram of airflow guidance between the top guide mechanism and the working cylinder of the present invention; Figure 3 A schematic diagram of the structure of a double-layer molybdenum-lanthanum insulation cylinder and a flow guide cylinder; Figure 4 This is a schematic diagram of the top structure of the inner cylinder; Figure 5 This is the original temperature change curve inside the inner cylinder; Figure 6 This is the temperature change curve inside the inner cylinder of the present invention.

[0015] Wherein: 1-Molybdenum-lanthanum inner cylinder, 2-Molybdenum-lanthanum outer cylinder, 3-Inner insulation layer, 4-Outer insulation layer, 5-Stainless steel outer cylinder, 6-Guide cylinder, 7-Inner cylinder, 8-Fan, 9-Drive motor, 10-Loading platform, 11-Water cooling channel, 12-Heat insulation screen chassis, 13-Guide cylinder base, 14-Top guide mechanism. Detailed Implementation

[0016] Example 1: A temperature control system that ensures temperature uniformity in the hot isostatic pressing working zone, such as Figures 1-4 As shown, the system includes a working cylinder with a working chamber inside. An inner cylinder 7 is located inside the working chamber. A top flow guiding mechanism 14 is positioned between the inner cylinder 7 and the working chamber to improve the temperature uniformity of the effective heat zone. The top flow guiding mechanism 14 includes a double-layer molybdenum-lanthanum insulation cylinder and a flow guiding cylinder 6. The double-layer molybdenum-lanthanum insulation cylinder comprises, from the inside out, a molybdenum-lanthanum inner cylinder 1, an inner insulation layer 3, a molybdenum-lanthanum outer cylinder 2, an outer insulation layer 4, and a stainless steel outer cylinder 5. A circulation pump mechanism is located at the bottom of the inner cylinder 7, and a loading platform 10 is located at the top of the circulation pump mechanism.

[0017] A first drainage channel is provided between the inner cylinder 7 and the double-layer molybdenum-lanthanum insulation cylinder, and a second drainage channel is provided between the double-layer molybdenum-lanthanum insulation cylinder and the guide cylinder 6. A third drainage channel is formed between the guide cylinder 6 and the inner wall of the working cylinder. A vent hole is provided at the top of the working chamber corresponding to the first drainage channel, and the top of the first drainage channel has an arc-shaped structure so that the high-temperature gas accumulated at the top of the working chamber flows from top to bottom in the first drainage channel. The bottom of the double-layer molybdenum-lanthanum insulation cylinder is connected to the second drainage channel so that the high-temperature gas flows from bottom to top in the second drainage channel. The top of the guide cylinder 6 is connected to the working chamber. The circulation pump mechanism is used to draw the high-temperature gas at the side wall of the working cylinder from top to bottom into the third drainage channel and into the inner cylinder 7 to achieve gas circulation.

[0018] Preferably, the double-layer molybdenum-lanthanum insulation cylinder mainly serves the functions of sealing and heat preservation. The double-layer molybdenum-lanthanum insulation cylinder can hinder most of the hot gas convection and reasonably guide the gas accumulated at the top of the hot zone to escape to the outside of the inner cylinder 7, thereby reducing the accumulation of high-temperature gas heat at the top of the hot zone.

[0019] like Figure 1 and Figure 3As shown, this invention employs a double-layer molybdenum-lanthanum insulation cylinder structure. An inner insulation layer 3 is filled between the inner molybdenum-lanthanum cylinder 1 and the outer molybdenum-lanthanum cylinder 2, while an outer insulation layer 4 is filled between the outer molybdenum-lanthanum cylinder 2 and the stainless steel outer cylinder 5. This effectively ensures airtightness, allowing gas to flow from the bottom into the guide cylinder 6 according to a predetermined flow direction. Preferably, the inner insulation layer 3 and the outer insulation layer 4 are made of high-performance ceramic fiber blankets, reducing heat loss through contact heat transfer. Simultaneously, the flexible and porous characteristics of the ceramic fiber blankets guide the convective heat transfer gas to gradually diffuse to the outside of the insulation screen.

[0020] Preferably, the innermost layer is a molybdenum-lanthanum inner cylinder 1, and the outermost layer is wrapped with a first layer of ceramic fiber blanket. The molybdenum-lanthanum outer cylinder 2 is installed on the outside of the ceramic fiber blanket, and a second layer of ceramic fiber blanket is laid on top, and finally fixed by a stainless steel outer cylinder 5.

[0021] Preferably, the bottom of the double-layer molybdenum-lanthanum insulation cylinder and the flow guide cylinder 6 are respectively provided with a heat insulation screen base 12 and a flow guide cylinder base 13. The heat insulation screen base 12 is installed on the flow guide cylinder base 13 so as to surround the double-layer molybdenum-lanthanum insulation cylinder inside the flow guide cylinder 6. The heat insulation screen base 12 has openings on its periphery to guide high-temperature gas into the second flow channel.

[0022] The molybdenum-lanthanum inner cylinder 1, the molybdenum-lanthanum outer cylinder 2, and the stainless steel outer cylinder 5 are respectively fixed on the heat insulation screen base 12. The heat insulation screen base 12 is mounted on the flow guide tube base 13, and the side openings of the heat insulation screen base 12 guide the airflow direction. The flow guide tube 6 is mounted on the flow guide tube base 13, surrounding the double-layer molybdenum-lanthanum insulation cylinder inside.

[0023] Several vent holes are radially opened on the periphery of the double-layer molybdenum-lanthanum insulation cylinder to guide convective gas outward and prevent heat accumulation at the top. The vent holes are connected to the interior of the heat insulation screen base 12 to allow gas to be introduced into the side openings of the heat insulation screen base 12, merge with the airflow guided from the first drainage channel, and flow into the second drainage channel at the guide cylinder 6.

[0024] The inner cylinder 1 and the outer cylinder 2 of the molybdenum-lanthanum are provided with corresponding vent holes to allow high temperature to flow into the insulation layer. The insulation material is generally a high-performance ceramic fiber blanket. This is to reduce heat loss from contact heat transfer and ensure that the internal temperature does not drop too quickly. It also utilizes the flexible and porous characteristics of ceramic fibers to guide the convective heat transfer gas to gradually diffuse to the outside of the insulation screen.

[0025] Preferably, such as Figure 3 As shown, the circumferential sidewalls of the molybdenum-lanthanum inner cylinder 1 and the molybdenum-lanthanum outer cylinder 2 are respectively provided with vent holes along the radial direction. The outer insulation layer 4 and the stainless steel outer cylinder 5 are respectively spaced apart, and the inner insulation layer 3 and the molybdenum-lanthanum outer cylinder 2 are respectively spaced apart, so as to guide the gas in the vent holes into the openings on the circumference of the heat insulation screen base 12.

[0026] Preferably, such as Figure 3As shown, the opening of the guide tube 6 is at the top, guiding the airflow from the bottom to the top. The guide tube 6 is sleeved and installed on the outside of the double-layer molybdenum-lanthanum insulation cylinder, with an opening at the top, so that the gas enters the guide tube 6 from below the double-layer molybdenum-lanthanum insulation cylinder and then flows out from the bottom to the top of the working cylinder.

[0027] A circulation pump mechanism is installed at the bottom of the inner cylinder 7. The circulation pump mechanism includes a fan 8 and a drive motor 9, which guides the gas from the top of the working cylinder to flow from top to bottom along the inner wall of the working cylinder, forming a gas circulation. A water-cooling channel 11 is provided on the side wall of the working cylinder. As the gas flows along the inner wall of the working cylinder, the gas will be cooled down by the water cooling effect, avoiding the accumulation and uncontrolled heat inside the working cylinder, forming a dynamic balance of heat - releasing heat while compensating for heat, thereby improving the temperature uniformity of the hot zone of the hot isostatic press.

[0028] like Figure 5 As shown, the temperature in the middle zone of the original isostatic press is significantly lower, while the temperature at the top accumulates noticeably, resulting in poor overall temperature uniformity. Figure 6 As shown, the temperature changes of the upper zone, middle zone, and bottom zone of the isostatic press of the present invention are basically consistent, which significantly improves the effect and solves the problem of temperature accumulation at the top.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone, characterized in that, The device includes a working cylinder, which has a working chamber inside. The working chamber has an inner cylinder (7) inside. A double-layer molybdenum-lanthanum insulation cylinder and a flow guide cylinder (6) are arranged between the inner cylinder (7) and the working chamber from the inside to the outside. A water cooling channel (11) is arranged around the side wall of the working cylinder. A circulation pump mechanism is arranged at the bottom of the inner cylinder (7). A first drainage channel is provided between the inner cylinder (7) and the double-layer molybdenum-lanthanum insulation cylinder, and a second drainage channel is provided between the double-layer molybdenum-lanthanum insulation cylinder and the guide cylinder (6). A third drainage channel is formed between the guide cylinder (6) and the inner wall of the working cylinder. A vent hole is provided at the top of the working chamber corresponding to the first drainage channel, and the top of the first drainage channel has an arc-shaped structure so that the high-temperature gas accumulated at the top of the inner cylinder (7) flows from top to bottom in the first drainage channel. The bottom of the double-layer molybdenum-lanthanum insulation cylinder is connected to the second drainage channel so that the high-temperature gas flows from bottom to top in the second drainage channel. The top of the guide cylinder (6) is connected to the working cylinder. The circulation pump mechanism is used to make the high-temperature gas at the side wall of the working cylinder flow from top to bottom in the third drainage channel and enter the inner cylinder (7) to realize gas circulation.

2. The temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to claim 1, characterized in that, The bottom of the double-layer molybdenum lanthanum insulation cylinder and the guide cylinder (6) are respectively provided with a heat insulation screen base (12) and a guide cylinder base (13). The heat insulation screen base (12) is installed on the guide cylinder base (13) so that the double-layer molybdenum lanthanum insulation cylinder is installed inside the guide cylinder (6). The heat insulation screen base (12) has openings on its periphery to guide high-temperature gas into the second drainage channel.

3. A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to claim 2, characterized in that, The double-layer molybdenum lanthanum insulation cylinder has several vent holes radially opened from top to bottom on its peripheral sidewalls to guide the convective gas outward and prevent heat accumulation at the top; the vent holes are connected to the openings on the periphery of the heat insulation screen chassis (12) to merge with the airflow guided from the first drainage channel into the second drainage channel.

4. A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to claim 3, characterized in that, The double-layer molybdenum-lanthanum insulation cylinder includes a molybdenum-lanthanum inner cylinder (1), an inner insulation layer (3), a molybdenum-lanthanum outer cylinder (2), an outer insulation layer (4), and a stainless steel outer cylinder (5) arranged sequentially from the inside to the outside. The circumferential sidewalls of the molybdenum-lanthanum inner cylinder (1) and the molybdenum-lanthanum outer cylinder (2) are respectively provided with vent holes in the radial direction. The outer insulation layer (4) and the stainless steel outer cylinder (5) and the inner insulation layer (3) and the molybdenum-lanthanum outer cylinder (2) are respectively spaced apart to guide the gas in the vent holes into the openings on the circumference of the heat insulation screen chassis (12).

5. A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to claim 4, characterized in that, The inner insulation layer (3) and the outer insulation layer (4) are respectively prepared from ceramic fiber blankets.

6. A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to claim 1, characterized in that, The top of the guide tube (6) is provided with several through holes arranged in an array to guide the airflow from the bottom to the top of the guide tube (6).

7. A temperature control system for ensuring temperature uniformity in the hot isostatic pressing working zone according to claim 6, characterized in that, The top of the guide tube (6) is provided with several through holes arranged in a ring array.

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