Safety guarantee system for low-temperature heating process of double-heat-storage heating furnace
By introducing an external open flame system into the dual regenerative heating furnace and using high-calorific-value LPG gas to form a stable ignition source, the problems of flame extinguishing and gas leakage during the low-temperature heating process are solved, achieving safe and economical combustion stability, reducing operation and maintenance costs and simplifying the system structure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING CISDI THERMAL & ENVIRONMENTAL ENG CO LTD
- Filing Date
- 2025-03-24
- Publication Date
- 2026-05-12
AI Technical Summary
Dual regenerative heating furnaces pose safety risks such as flameout and gas leakage during the low-temperature heating process. In particular, the combustion stability of low-calorific-value blast furnace gas is poor, which can easily lead to flameout or backfire. Moreover, existing technologies lack economical, reliable, and adaptable solutions.
An external open flame system is adopted, which uses a high-temperature resistant steel pipe inserted into the inspection port of the furnace burner to form a stable ignition source through a high-calorific-value LPG gas source. Combined with the series configuration of check valve and shut-off valve, the stable combustion of low-calorific-value gas is ensured, and the system’s flexibility and adaptability are achieved through modular design.
It effectively solves the problem of poor combustion stability of low-calorific-value gas, improves the safety and economy of the system, reduces operation and maintenance costs, and the system design is flexible and adaptable to different working conditions, avoiding the need to modify the furnace structure.
Smart Images
Figure CN224230003U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of industrial heating furnace technology, and relates to a safety assurance system for the low-temperature heating process of a dual regenerative heating furnace. Background Technology
[0002] As a key piece of equipment for high efficiency and energy saving in the steel industry, the core advantage of the dual regenerative heating furnace lies in recovering waste heat from flue gas through a regenerator, preheating air and coal gas to high temperatures (typically above 1000℃), thereby significantly reducing fuel consumption and pollutant emissions. After the dual regenerative heating furnace is constructed, it will undergo low-temperature baking and high-temperature baking according to a predetermined furnace baking curve. Low-temperature baking removes free water from the castable (or plastic) material, while high-temperature baking removes crystal water from special components of the castable (or plastic). High-quality furnace baking can effectively improve the service life of the heating furnace refractory materials and enhance their insulation and energy-saving effects. Secondly, during normal operation of the dual regenerative heating furnace, it will be shut down for periodic equipment maintenance and removal of oxidized steel slag. After the equipment maintenance and removal of oxidized steel slag are completed, the furnace temperature will be raised to the required temperature for the billet heating furnace according to the heating curve; this heating curve includes both low-temperature and high-temperature heating processes.
[0003] It is evident that both the initial furnace drying process and the heating process after regular maintenance and removal of oxidized steel slag in the dual regenerative furnace require a low-temperature heating process. Furnace drying is a necessary step for the dual regenerative furnace to resume production after commissioning or maintenance. Its core objective is to remove free water and crystal water from the refractory material through gradient heating, ensuring the stability of the furnace structure. According to the established process, the low-temperature furnace drying stage (≤700℃) relies on the furnace drying burner for heating, while the high-temperature heating process and normal production process switch to the dual regenerative burner. However, when the furnace drying burner uses low-calorific-value blast furnace gas (calorific value ≤850kCal / Nm³),... 3 Due to its poor combustion characteristics and slow flame propagation speed, the double regenerative furnace is prone to flameout or flashback in low-temperature environments. Flameout can cause combustion interruption during the low-temperature furnace baking process, and unburned gas can leak into the furnace and pipelines, mixing with air to form explosive gases. Flashback may burn the burner and gas supply equipment, causing safety accidents.
[0004] In summary, achieving safe and stable combustion in dual regenerative furnaces during the low-temperature furnace drying stage, preventing gas leaks and abnormal flames, while simultaneously simplifying the system structure and reducing operation and maintenance costs, remains a critical technical challenge in this field. Existing technologies have not yet provided a solution that balances economy, reliability, and adaptability, especially in scenarios where low-calorific-value gas is directly applied to the furnace burner; innovative designs are urgently needed to fill this gap. Utility Model Content
[0005] In view of this, the purpose of this utility model is to provide a safety assurance system for the low-temperature heating process of a dual regenerative heating furnace, so as to solve the safety problems of flame extinguishing and gas leakage in the low-temperature heating process of a dual regenerative heating furnace.
[0006] To achieve the above objectives, this utility model provides the following technical solution:
[0007] A safety assurance system for the low-temperature heating process of a dual regenerative heating furnace includes a dual regenerative heating furnace, wherein the dual regenerative heating furnace includes a furnace body and a furnace burner arranged on the furnace body, the furnace burner having an air interface, a gas interface and an inspection port, and also includes an external open flame system.
[0008] The external open flame system includes an open flame nozzle, a check valve, a connecting hose, and a gas cylinder connected in series. The open flame nozzle is inserted into the furnace burner through an inspection port so that the constant flame of the open flame nozzle can be used to ensure the combustion of low-calorific-value blast furnace gas in the furnace burner during the low-temperature heating process of the dual regenerative heating furnace.
[0009] Each burner in the dual regenerative heating furnace must be equipped with an external open flame system; all the burners and external open flame systems together form a safety assurance system for the low-temperature heating process.
[0010] Furthermore, a shut-off valve is provided between the check valve and the connecting hose; the check valve can prevent the gas in the open flame nozzle from flowing back into the gas tank.
[0011] Furthermore, the shut-off valve is a ball valve or a gate valve; the shut-off valve should have the following functions: effectively shut off the high-calorific-value gas supplied by the LPG tank, and improve the safety of the external open flame system.
[0012] Furthermore, an adjustment shut-off valve is installed on the top of the gas tank to adjust the output flow rate of the gas tank.
[0013] Furthermore, the gas cylinder is filled with high-calorific-value LPG, but other high-calorific-value coal gases can also be used to replace the high-calorific-value LPG.
[0014] Furthermore, the open flame nozzle is made of high-temperature resistant steel pipe.
[0015] Furthermore, the outer diameter of the high-temperature resistant steel pipe is smaller than the inner diameter of the viewing port, so as to facilitate insertion into the viewing port.
[0016] Furthermore, the connecting hose is made of stainless steel corrugated hose or synthetic rubber hose.
[0017] The beneficial effects of this utility model are as follows:
[0018] 1. This utility model effectively solves the core problem of poor combustion stability of low-calorific-value blast furnace gas through a groundbreaking design of an external open flame system. The system uses an independent LPG gas source, directly inserted into the furnace burner via a high-temperature resistant steel pipe, utilizing high-calorific-value gas to form a stable ignition source, ensuring continuous combustion of low-calorific-value gas at low temperatures. The series configuration of a check valve and a double shut-off valve forms a triple protection mechanism, preventing gas backflow into the gas tank and quickly cutting off the gas source, significantly improving the system's inherent safety level.
[0019] 2. Modular design gives the system flexible adaptability to operating conditions. The external open flame system is only used during the low-temperature heating stage. When entering the high-temperature operation or production stage, the system can be taken offline by quickly disassembling the connecting hose, which not only avoids occupying space in the furnace maintenance passage, but also extends the service life of core components. The insertion structure of the inspection port, combined with the outer diameter adaptation design, allows for installation without modifying the furnace body, achieving plug-and-play functionality.
[0020] 3. Compared to traditional high-calorific-value gas transmission systems, this solution offers significant economic and operational advantages. Replacing fixed pipelines with mobile gas tanks reduces initial investment by approximately 40%; the combined application of stainless steel corrugated hoses and synthetic rubber hoses ensures airtightness while reducing maintenance costs. This design, while maintaining safety redundancy, achieves lightweight equipment and functional integration, providing a cost-effective solution for upgrading the safety of industrial furnaces and kilns.
[0021] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description
[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:
[0023] Figure 1 This is a schematic diagram of the dual regenerative heating furnace in the embodiment;
[0024] Figure 2 This is a schematic diagram of the safety assurance system for the low-temperature heating process of a dual regenerative heating furnace in an embodiment.
[0025] Figure reference numerals: 1-Heating furnace body; 2-Dual regenerative burner; 3-Baking furnace burner; 4-1-Open flame nozzle; 4-2-Check valve; 4-3-Shut-off valve; 4-4-Connecting hose; 4-5-LPG gas tank. Detailed Implementation
[0026] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0027] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.
[0028] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0029] Example 1
[0030] Please see Figures 1-2 This is a safety assurance system for the low-temperature heating process of a dual regenerative heating furnace, comprising a dual regenerative heating furnace 1 and an external open flame system;
[0031] The dual regenerative heating furnace 1 includes a furnace body steel structure, furnace body refractory material, and dual regenerative burners 2 and furnace drying burners 3 arranged on the furnace body steel structure; the dual regenerative burners 2 include an air regenerative box, a gas regenerative box, and a regenerative honeycomb structure inside the box; the furnace drying burners 3 include an air interface, a gas interface, and an inspection port.
[0032] The dual regenerative heating furnace uses blast furnace gas as fuel. It heats cold blast furnace gas and cold air to ~1000℃ through a regenerative honeycomb structure. The hot blast furnace gas and hot air are mixed and burned to meet the temperature requirements inside the furnace. However, blast furnace gas has a low calorific value (≤850 kcal / Nm³).3 The inherent characteristics of poor combustion stability (easy to detach and flashback at low temperatures) lead to safety issues such as flameout and gas leakage in the dual regenerative heating furnace during the low-temperature heating process.
[0033] The low-temperature heating process includes the furnace start-up heating process after the furnace is first built or after it is shut down, where the low-temperature process generally refers to room temperature to 700°C.
[0034] The external open flame system includes an open flame nozzle 4-1, a check valve 4-2, a shut-off valve 4-3, a connecting hose 4-4, and an LPG (liquefied petroleum gas) tank 4-5 connected in series. The safety assurance system refers to the use of the high-calorific-value gas from the open flame nozzle 4-1 in the external open flame system to insert into the inspection port of the furnace burner 3, thereby ensuring the stable and safe combustion of low-calorific-value blast furnace gas in the furnace burner 3.
[0035] Specifically, the open flame nozzle 4-1 is made of high-temperature resistant steel pipe, and the outer diameter of the high-temperature resistant steel pipe is smaller than the inner diameter of the inspection port, so as to facilitate insertion into the inspection port; the connecting hose 4-4 is made of stainless steel corrugated hose or synthetic rubber hose.
[0036] The low-temperature baking process of the dual regenerative heating furnace is maintained by burning low-calorific-value blast furnace gas through the baking burner 3 to maintain the low-temperature heating process of the dual regenerative heating furnace.
[0037] The high-temperature heating process and normal production process of the dual regenerative heating furnace are maintained by the combustion of low-calorific-value blast furnace gas by the dual regenerative burner 2.
[0038] The low-calorific-value blast furnace gas has a low calorific value (≤850 kcal / Nm³). 3 Due to its inherent characteristics of poor combustion stability (easily detached and flashed at low temperatures), an external open flame system is required to solve safety issues such as flameout and gas leakage during the low-temperature heating process of the dual regenerative heating furnace.
[0039] This utility model addresses the safety issues of flameout and gas leakage during the low-temperature heating process of dual regenerative heating furnaces by providing a safety assurance system for the low-temperature heating process of dual regenerative heating furnaces, which can effectively solve the safety problems during the low-temperature heating process of dual regenerative heating furnaces.
[0040] Example 2
[0041] The specific implementation steps of the safety assurance system for the low-temperature heating process of the dual regenerative heating furnace are as follows:
[0042] 1) The initial construction process of the dual regenerative heating furnace, as well as the completion of regular maintenance and removal of oxidized steel slag, requires the completion of the low-temperature heating process and the high-temperature heating process according to the established curve;
[0043] 2) Nitrogen purging of the furnace piping is complete, and gas replacement of the furnace piping is complete;
[0044] 3) According to the heating requirements, turn on the oven burners 3 one or more at a time;
[0045] 4) Low-calorific-value blast furnace gas is normally introduced into the oven drying pipeline and burned at the outlet of the oven drying burner that has been turned on to supply heat to the dual regenerative heating furnace.
[0046] 5) External open flame system according to Figure 2 Installation complete;
[0047] 6) Open the check valve 4-2, the shut-off valve 4-3, and the outlet regulating shut-off valve at the top of the LPG tank 4-5 in sequence, and manually ignite the LPG gas at the end of the open flame nozzle 4-1;
[0048] 7) Insert the lit open flame nozzle 4-1 into the inspection port of the oven burner 3;
[0049] 8) The gap between the open flame nozzle 4-1 and the inspection port of the furnace burner 3 is filled with a high-temperature resistant ceramic fiber blanket to prevent hot flue gas from escaping from the furnace.
[0050] The above embodiments are only one implementation of this utility model, but the scope of protection is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this invention should be included within the scope of protection of this invention, such as changing the type of dual regenerative burner, the definition and name of the dual regenerative burner, the number of furnace burners, the external gas tank high-calorific-value gas, the configuration of the external open flame system valves, etc.
[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A safety assurance system for the low-temperature heating process of a dual-regenerative heating furnace, comprising a dual-regenerative heating furnace, wherein the dual-regenerative heating furnace includes a furnace body and a furnace burner arranged on the furnace body, the furnace burner having an air inlet, a gas inlet, and an inspection port, characterized in that: This also includes external open flame systems; The external open flame system includes an open flame nozzle, a check valve, a connecting hose, and a gas cylinder connected in series. The open flame nozzle is inserted into the furnace burner through an inspection port so that the constant flame of the open flame nozzle can be used to ensure the combustion of low-calorific-value blast furnace gas in the furnace burner during the low-temperature heating process of the dual regenerative heating furnace.
2. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 1, characterized in that: A shut-off valve is also provided between the check valve and the connecting hose.
3. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 2, characterized in that: The shut-off valve is either a ball valve or a gate valve.
4. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 1, characterized in that: An adjusting shut-off valve is installed on the top of the gas tank to regulate the output flow rate of the gas tank.
5. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 1, characterized in that: The gas cylinder is filled with high-calorific-value LPG.
6. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 1, characterized in that: The open flame nozzle is made of high-temperature resistant steel pipe.
7. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 6, characterized in that: The outer diameter of the high-temperature resistant steel pipe is smaller than the inner diameter of the viewing port, so as to facilitate insertion into the viewing port.
8. The safety assurance system for the low-temperature heating process of the dual regenerative heating furnace according to claim 1, characterized in that: The connecting hose is made of stainless steel corrugated hose or synthetic rubber hose.