Description:FIELD OF THE INVENTION

The present invention in general relates to the field of thermal processing and surface hardening technologies. Particularly, the present invention relates to an ammonia gas nitriding furnace designed for the hardening of die steel. This furnace significantly enhances the surface hardness, wear resistance, and fatigue strength of die steel components, making it particularly advantageous for manufacturing industries that require highly durable and long-lasting metal parts.

BACKGROUND OF THE INVENTION

In the manufacturing industry, particularly in the production of aluminium extrusion profiles, the hardness and durability of die steel are critical factors that directly influence the quality and longevity of the final product. Traditional methods of hardening die steel often fail to provide the necessary enhancements in surface hardness and lifespan, resulting in frequent die replacements and escalating operational costs. This highlights an urgent need for a more effective and reliable solution in die steel hardening technology.

Ammonia gas nitriding has emerged as a superior method for addressing these challenges. This process introduces ammonia gas to form a hard, wear-resistant surface layer on the steel, significantly improving surface hardness, wear resistance, and fatigue strength. Despite its advantages, conventional ammonia nitriding systems often lack the efficiency and precision required for optimal results, underlining the necessity for innovation in this field.

The need for our invention becomes evident when considering the additional benefits it offers. Enhanced surface hardness of the dies not only prolongs their life but also results in aluminium extrusion profiles with a more refined and polished surface, significantly increasing their shine and aesthetic appeal. This is particularly important in industries where the visual quality of aluminium products is paramount.

Our invention addresses these needs by introducing an advanced ammonia gas nitriding furnace that employs both ammonia and nitrogen gases to optimize the hardening process. Ammonia is utilized for its effective hardening properties, creating a robust and wear-resistant surface on the die steel. Concurrently, nitrogen is used for controlled and uniform cooling of the dies post-treatment, enhancing the stability and efficiency of the furnace operation.

This dual-gas approach not only enhances the hardening process but also ensures the durability and quality of the treated dies. By improving the surface hardness, wear resistance, and fatigue strength of die steel, our invention significantly extends the lifespan of dies and elevates the quality of aluminium extrusion profiles. This innovation is crucial for manufacturing industries, offering substantial benefits by reducing operational costs, improving product quality, and meeting the stringent demands of modern production environments.

In summary, the development of our ammonia gas nitriding furnace represents a critical advancement in die steel hardening technology, addressing the pressing needs for improved durability, efficiency, and quality in aluminium extrusion profile production.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

These and other features, aspect, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein the device and process and digester configurations described in the present invention are explained in more detail with reference to the following drawings:

Figure 1 illustrates the external schematic view of the furnace.

While the invention is described in conjunction with the illustrated embodiment, it is understood that it is not intended to limit the invention to such embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention disclosure as defined by the claims.

SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention nor is it intended to determine the scope of the invention.
In an aspect of the present invention, there is provided a furnace (14) for ammonia gas nitriding comprising:
a round mild-steel (hot rolled sheets) structure from the outside and stainless steel (SS 304) structure from the inside comprising an inner pot (15) to form a cylindrical assembly;

an inner pot (15) of the furnace (14) comprising a Stainless Steel 304 port (8) as its surface, a heater (9) beneath the surface of inner pot (15) and a refractory (13) in between the heater (9) and the outer surface (16) of the furnace (14);

a top door (3) of the furnace (14) comprising at its outer side a motor housing (1) at the center, a hydraulic cylinder (4) fixed across the surface from center to its edge and a thermocouple (10) embedded at the surface;

a top door (3) of the furnace (14) comprising at its inward side a Stainless Steel Impeller (2) at the center, a silicon seal (6) at the edge and a plurality of water jackets (7); and

a top door (3) of the furnace (14) comprising at its sides a plurality of door clamps (5), an inlet pipe (11) and an outlet pipe (12).

In an embodiment of the present invention, there is provided a furnace (14), wherein the outer walls are made up of mild-steel (hot rolled sheets) and inner pot (15) surface is made up of stainless steel (SS 304).

In another embodiment of the present invention, there is provided a furnace (14), wherein the heater (9) is provided in the upper furnace layer to raise the temperature to 550 degree Celsius.

In yet another embodiment of the present invention, there is provided a furnace (14), wherein the refractory (13) is provided for thermal insulation and structural integrity.

In still another embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) comprises a motor housing (1) made up of 8” seamless pipe accommodating both the motor and fan assembly.

In an embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) further comprises a hydraulic cylinder (4) to operate the top door (3) thereby facilitating easy material placement and removal.

In another embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) comprises a thermocouple (10) embedded at the top door (3) to monitor material temperature thereby ensuring precise temperature control throughout the process.

In yet another embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) further comprises a Stainless Steel Impeller (2) to facilitate efficient air supply within the furnace.

In still another embodiment of the present invention, there is provided a furnace (14), wherein the silicon seal (6) into the top door (3) to securely seal it preserving internal heat and gas.

In an embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) further comprises a plurality of water jackets (7) to facilitate circulation of water within the upper furnace and door area housing bearings.

In another embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) comprises a plurality of door clamps (5) to securely seal the furnace after material is inserted.

In yet another embodiment of the present invention, there is provided a furnace (14), wherein the furnace (14) further comprises the inlet pipe (11) to enable controlled entry of ammonia and nitrogen gases into the furnace.

In still another embodiment of the present invention, there is provided a furnace (14), wherein the outlet pipe (12) is provided to facilitate safe gas discharge.

These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description. This summary is provided to introduce a selection of concepts in a simplified form.

DETAILED DESCRIPTION OF THE INVENTION

Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps of the process, features of the invention, referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features.

Definitions
For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are collected here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person skilled in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference. The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally equivalent products and methods are clearly within the scope of the disclosure, as described herein.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and/or alternative adaptations, specific embodiments thereof has been shown by way of examples and will be described in detail below. However, it should be understood, that it is not intended to limit the invention to the particular structural arrangement disclosed, but on the contrary, the invention is to cover all modifications, structural adaptations and alternative falling within the spirit and the scope of the invention as defined herein.

The present invention in general relates to the field of thermal processing and surface hardening technologies. Particularly, the present invention relates to an ammonia gas nitriding furnace designed for the hardening of die steel. This furnace significantly enhances the surface hardness, wear resistance, and fatigue strength of die steel components, making it particularly advantageous for manufacturing industries that require highly durable and long-lasting metal parts.

Thus, in accordance with the present invention there is provided a furnace (14) for ammonia gas nitriding comprising:
a round mild-steel (hot rolled sheets) structure from the outside and stainless steel (SS 304) structure from the inside comprising an inner pot (15) to form a cylindrical assembly;

an inner pot (15) of the furnace (14) comprising a Stainless Steel 304 port (8) as its surface, a heater (9) beneath the surface of inner pot (15) and a refractory (13) in between the heater (9) and the outer surface (16) of the furnace (14);

a top door (3) of the furnace (14) comprising at its outer side a motor housing (1) at the center, a hydraulic cylinder (4) fixed across the surface from center to its edge and a thermocouple (10) embedded at the surface;

a top door (3) of the furnace (14) comprising at its inward side a Stainless Steel Impeller (2) at the center, a silicon seal (6) at the edge and a plurality of water jackets (7); and

a top door (3) of the furnace (14) comprising at its sides a plurality of door clamps (5), an inlet pipe (11) and an outlet pipe (12).

Figure 1 is a furnace that is constructed in accordance with a preferred embodiment of the present invention. The present invention introduces an advanced ammonia gas nitriding furnace designed to revolutionize the hardening of die steel components. By significantly enhancing surface hardness, wear resistance, and fatigue strength, this furnace becomes an indispensable asset for manufacturing industries demanding highly durable and long-lasting metal parts.

The core of the furnace is its furnace, a cylindrical assembly combining an outer structure of mild steel (hot rolled sheets) with an inner structure made of Stainless Steel 304 (SS 304). Inside, the inner pot of SS 304 ensures a robust surface. Beneath this surface lies a heater, separated from the furnace's outer surface by a refractory layer, promoting efficient heat distribution and structural integrity.

The top door of the furnace boasts a sophisticated design. Externally, it features a motor housing crafted from an 8" seamless pipe, accommodating both motor and fan assembly. A hydraulic cylinder, fixed across the surface, facilitates the effortless opening and closing of the door by lifting and rotating it to the side. Embedded thermocouples precisely monitor temperature, ensuring optimal process control. Internally, a SS 304 impeller ensures efficient air supply for uniform ammonia gas distribution, while a silicone seal prevents leakage. The integration of water jackets enhances the longevity of bearings and the silicone seal through effective water circulation. Robust door clamps securely seal the door after material insertion, preserving internal heat and gas. Additionally, dedicated inlet and outlet pipes enable controlled gas entry and safe discharge, respectively.

The gas inlet and outlet systems are meticulously designed. Dedicated pipes facilitate the controlled entry of ammonia and nitrogen gases via a low-pressure regulator, while an outlet pipe directs used gases to a water tank for neutralization before safe atmospheric release.

Heating and insulation are key features of this furnace. A heater in the upper furnace layer elevates the temperature to 550°C for optimal heat treatment. The furnace's structure is fortified with high-quality insulation materials, including ceramic blankets, insulation bricks, and element-holding bricks, ensuring superior thermal insulation and structural durability. The outer surface maintains a maximum temperature of 40°C or atmospheric temperature, ensuring operational safety.

Material insertion and removal are seamless due to the furnace's specially designed material insertion door. This leak-proof door allows for easy loading and unloading of materials. Inside, a rack system supported by ammonia and nitrogen gas supply systems facilitates precise material placement.

Operational efficiency is a hallmark of this furnace. For a 2kg pressure operation, ammonia introduced from the bottom at 550°C forms a 15-20 micron layer on the die steel surface, resulting in a 15-20% increase in hardness, improved shine, and extended die life. Rapid cooling is achieved using nitrogen, with pressure adjustments expediting the process. The top door remains closed until the furnace has cooled down, ensuring safety. A low-pressure regulator valve prevents gas escape in case of malfunction, rendering the furnace accident-proof.

The furnace's advantages are manifold. Enhanced surface hardness, wear resistance, and fatigue strength extend the lifespan of die steel components. Uniform ammonia gas distribution is ensured by the SS 304 impeller, while embedded thermocouples provide precise temperature control. The robust construction using SS 304 and advanced insulation materials guarantees long-lasting performance. Safety features, including the low-pressure regulator valve and controlled cooling, ensure safe operation. Moreover, the furnace's design allows for easy maintenance, and its components are readily available in India.

In conclusion, this ammonia gas nitriding furnace combines innovative features with operational excellence, offering substantial benefits for industries requiring durable and long-lasting metal parts. Its advanced design and impressive performance make it an essential tool in modern manufacturing.
, Claims:We Claim:

1. A furnace (14) for ammonia gas nitriding comprising:

a round mild-steel (hot rolled sheets) structure from the outside and stainless steel (SS 304) structure from the inside comprising an inner pot (15) to form a cylindrical assembly;

an inner pot (15) of the furnace (14) comprising a Stainless Steel 304 port (8) as its surface, a heater (9) beneath the surface of inner pot (15) and a refractory (13) in between the heater (9) and the outer surface (16) of the furnace (14);

a top door (3) of the furnace (14) comprising at its outer side a motor housing (1) at the center, a hydraulic cylinder (4) fixed across the surface from center to its edge and a thermocouple (10) embedded at the surface;

a top door (3) of the furnace (14) comprising at its inward side a Stainless Steel Impeller (2) at the center, a silicon seal (6) at the edge and a plurality of water jackets (7); and

a top door (3) of the furnace (14) comprising at its sides a plurality of door clamps (5), an inlet pipe (11) and an outlet pipe (12).

2. The furnace (14) as claimed in claim 1, wherein the outer walls are made up of mild-steel (hot rolled sheets) and inner pot (15) surface is made up of stainless steel (SS 304).

3. The furnace (14) as claimed in claims 1-2, wherein the heater (9) is provided in the upper furnace layer to raise the temperature to 550 degree Celsius.

4. The furnace (14) as claimed in claim 1, wherein the refractory (13) is provided for thermal insulation and structural integrity.

5. The furnace (14) as claimed in claim 1, wherein the furnace (14) comprises a motor housing (1) made up of 8” seamless pipe accommodating both the motor and fan assembly.

6. The furnace (14) as claimed in claim 1, wherein the furnace (14) further comprises a hydraulic cylinder (4) to operate the top door (3) thereby facilitating easy material placement and removal.

7. The furnace (14) as claimed in claim 6, wherein the furnace (14) comprises a thermocouple (10) embedded at the top door (3) to monitor material temperature thereby ensuring precise temperature control throughout the process.

8. The furnace (14) as claimed in claim 1, wherein the furnace (14) further comprises a Stainless Steel Impeller (2) to facilitate efficient air supply within the furnace.

9. The furnace (14) as claimed in claim 1, wherein the silicon seal (6) into the top door (3) to securely seal it preserving internal heat and gas.

10. The furnace (14) as claimed in claim 1, wherein the furnace (14) further comprises a plurality of water jackets (7) to facilitate circulation of water within the upper furnace and door area housing bearings.

11. The furnace (14) as claimed in claim 1, wherein the furnace (14) comprises a plurality of door clamps (5) to securely seal the furnace after material is inserted, the inlet pipe (11) to enable controlled entry of ammonia and nitrogen gases into the furnace, and the outlet pipe (12) is provided to facilitate safe gas discharge.