Non-fixed station sand box pouring high temperature flue gas capturing method

Abstract

This invention discloses a method for capturing high-temperature flue gas during sand casting in a non-fixed-position sand box. The method utilizes a flue gas capture device and includes: ① After determining the sand box location, a crane transports the casting ladle to the top of the sand box and prepares for casting; ② A movable support moves the suction hood to the casting position; ③ The dust removal system is activated, and the valve connected to the suction hood is opened. Simultaneously, the blower in the air curtain generating pipe is turned on, forming an air curtain covering the upper side of the casting ladle; ④ After casting, the movable support moves the suction hood to another position, and the crane removes the casting ladle. This invention allows for adjusting the position of the movable support according to the casting location for flue gas capture and treatment, significantly improving the flue gas capture effect.

Description

Technical Field

[0001] This invention relates to the field of high-temperature flue gas capture technology, and in particular to a method for capturing high-temperature flue gas using a non-fixed-position sand box casting process. Background Technology

[0002] The capture and purification of flue gas during the casting of large castings is a challenging issue in ground-casting casting processes. Because sand boxes (cores), ladles, and castings are transported by crane in ground-casting processes, and because there are lifting ropes above the casting area during casting, it is difficult to install capture hoods on top of the high-temperature flue gas source for effective flue gas capture. Using side-suction hoods is one of the traditional methods for capturing casting flue gas; this involves arranging several side-suction hoods on one side of the casting area and activating the appropriate hood based on the casting position to capture the flue gas. During use, the following problems were found with the side-suction hood method for capturing casting fumes: 1. High ventilation volume (taking a 20-ton ladle as an example, the capture air volume of the capture equipment reaches 150,000-200,000 m³ / h), resulting in high initial investment in the system and equipment, high operating energy consumption, and high cost of replacing filter media; 2. The capture effect of the side-suction hood is not good due to the influence of the casting volume, ladle size, and cross ventilation in the workshop; 3. The side-suction hood is large in size and occupies a large area, leading to a reduction in the space utilization rate inside the workshop; 4. The side-suction hood is heavy, and if it is fixed to the side wall or column of the building, the side wall or column needs to be reinforced, increasing costs. These problems are important limiting factors for the implementation of the side-suction hood casting high-temperature fume capture project, which is not conducive to the environmental protection transformation and green development of foundry enterprises. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a method for capturing high-temperature flue gas during non-fixed-position sand casting, which is achieved through a flue gas capture device, as detailed below:

[0004] The flue gas capture device includes:

[0005] A suction hood is installed on the side above the pouring pit, and the outlet end of the suction hood is connected to the dust removal system through a sliding sealing tube mechanism.

[0006] A movable support is straddling the top of the pouring pit and slidably connected to guide rails on both sides of the pouring pit. The top of the movable support is provided with an opening structure for accommodating the crane rope, and the side of the movable support is provided with a wind baffle. The wind baffle extends upward and is connected to the inlet end of the suction hood.

[0007] An air curtain generating pipe is installed on the top of the movable support. The air curtain generating pipe is a U-shaped structure composed of a first section, a second section and a third section connected in sequence. The first section has an air outlet that is angled upward and opposite to the wind baffle. The third section is parallel to the first section and has a return air outlet. The second section is equipped with a blower.

[0008] The capture method includes the following steps:

[0009] S1. After the sand box position is determined, the crane will transport the pouring ladle to the top of the sand box and prepare for pouring.

[0010] S2, the suction hood is moved to the pouring position by moving the support;

[0011] S3, start the dust removal system and open the valve connected to the suction hood. At the same time, turn on the air supply fan in the air curtain generating pipe to form an air curtain covering the upper side of the pouring ladle.

[0012] S4. After the pouring is completed, the suction hood is moved to another work station by moving the support frame, and the crane moves the pouring ladle away at the same time.

[0013] The movable support includes two square frames and a top crossbar for connecting the two. The bottom of the square frames is slidably connected to the guide rail, and the top crossbar is positioned near one end of the square frames.

[0014] The bottom of the baffle plate is sealed to a square frame near the suction hood, and the top of the baffle plate is inclined toward the pouring pit and is provided with an installation port that matches the inlet of the suction hood.

[0015] The wind deflector is provided with vertical baffles on both sides, a first horizontal baffle that is vertically downward is provided on the top edge of the wind deflector, and a second horizontal baffle located above the first section of the air curtain generating pipe is provided in the middle of the wind deflector along the horizontal direction.

[0016] The return air inlet is positioned directly opposite the first section of the air curtain generating pipe.

[0017] The centerline of the air outlet is deflected downwards by 3°-5° along the centerline of the suction hood.

[0018] The non-fixed-position sand casting high-temperature flue gas capture method provided by this invention is achieved through a stable and easy-to-use flue gas capture device. This device can adjust the position of the movable support according to the casting location for flue gas capture and treatment, reducing the number of suction hoods, lowering initial equipment investment and operating costs, and improving the space utilization rate inside the workshop. The air outlet of the aforementioned air curtain generating pipe can form an air curtain above the casting ladle to resist the force of the high-temperature flue gas jet from the casting and ladle and change the flow direction of the jet, thereby allowing the suction hood to capture the casting flue gas with a smaller ventilation volume. Since the air in the air curtain originates from the casting flue gas, it can reduce the air volume and upward force of the jet, which is beneficial for the air curtain to capture the casting flue gas, thus significantly improving the flue gas capture effect.

[0019] Based on simulation analysis and engineering design, compared with the traditional side-suction hood solution, the present invention can reduce ventilation volume by about 70%, ventilation and heating energy consumption by 70%, ventilator energy consumption by 90%, and cost reduction by about 35%, and the capture effect is better than the traditional solution. At the same time, it can also improve the environmental protection effect of the foundry workshop, improve occupational health in the workshop, and has a good green and low-carbon effect, with significant social, environmental and economic benefits. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the flue gas collection device described in this invention.

[0021] Figure 2 This is a simulation diagram of the airflow organization effect during flue gas capture according to the present invention. Detailed Implementation

[0022] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific working processes are given. However, the scope of protection of the present invention is not limited to the following embodiments.

[0023] like Figure 1 As shown, the non-fixed-position sand box casting high-temperature flue gas capture method of the present invention is realized by a flue gas capture device, which includes an integrated movable support 1 and a suction hood 2. The weight of the suction hood 2 is mainly borne by the movable support 1. It is set above the side of the casting pit M, and the outlet end is connected to the dust removal system through a sliding sealing pipe mechanism.

[0024] The aforementioned sliding sealing pipe mechanism adopts the dust removal method of the single-track telescopic hood (CN2022106753521). It includes a longitudinal exhaust pipe 31 located at the inlet of the dust removal unit. The top surface of the longitudinal exhaust pipe 31 has a longitudinal groove, and a sealing belt that is adsorbed by negative pressure is installed on the longitudinal groove. It also includes a movable duct connector 32 located at the outlet of the suction hood 2. The movable duct connector 32 includes a pipe connector connected to the outlet of the suction hood 2 and a sealing cover located outside the pipe connector. The pipe connector is located between the sealing belt and the longitudinal exhaust pipe 31, and its lower opening corresponds to the longitudinal groove. The sealing cover is located outside the sealing belt, and its lower opening is sealed to the sealing belt. Because the lower opening of the pipe connector is always connected to the longitudinal exhaust pipe 31, and the sealing belt on its outer side can keep the longitudinal groove of the longitudinal exhaust pipe 31 sealed when subjected to negative pressure adsorption, smooth smoke exhaust can still be achieved even after the suction hood 2 is moved by the sliding sealing pipe mechanism.

[0025] The aforementioned movable support 1, connected to the suction hood 2 via the wind deflector 4, spans above the pouring pit M and is slidably connected to the guide rails 5 located on both sides of the pouring pit M. Specifically, the movable support 1 is a steel support, comprising two square frames and a top crossbar connecting the two. The bottom of each square frame is slidably connected to the guide rail 5 via rollers. The top crossbar is positioned near one end of the square frames, thereby creating an opening at the top of the movable support 1 to accommodate the crane rope 6, facilitating the lifting of the pouring ladle, etc.

[0026] The baffle plate 4 is located on the side of the movable support 1 near the suction hood 2, and is a steel plate with a bent structure at the top. The bottom of the baffle plate 4 is sealed to the square frame, and the bent surface at the top is inclined to the side of the pouring pit M. It has an installation port that matches the inlet of the suction hood 2 for welding connection with the suction hood 2. The baffle plate 4 is used to cooperate with the air curtain generating pipe 7 to form an air curtain, preventing the high-temperature flue gas from escaping during pouring and improving the capture effect of the suction hood 2.

[0027] The aforementioned air curtain generating pipe 7 is installed on the top of the movable support 1. It is a U-shaped structure composed of a first section, a second section, and a third section connected in sequence. The opening direction of the U-shaped structure is consistent with the opening direction of the top of the movable support 1, which facilitates the hoisting of the pouring ladle. The first section of the aforementioned air curtain generating pipe 7 is located on the side away from the wind baffle 4, and has an air supply port 71 that is angled upward towards the wind baffle 4. Preferably, the center line of the air supply port 71 is deflected downward by 3°-5° along the center line of the suction hood 2. The third section is parallel to the first section and is located close to the wind baffle 4. The third section has a return air port 72 that faces the first section. The second section is equipped with a blower 73.

[0028] When the high-temperature flue gas generated during sand casting flows upward under the action of buoyancy, it is first drawn into the return air inlet 72 by the suction action of the blower 63, and then sent out through the air outlet 71 to form an air curtain. After that, a small portion of the casting flue gas enters the return air inlet 72, while most of the casting flue gas changes its flow direction under the action of the air curtain and is captured by the suction hood 2 (see Figure 2 ).

[0029] To prevent smoke escape, vertical baffles 41 with a width of 300-500mm are further provided on both sides of the baffle plate 4, a first horizontal baffle 42 extending vertically downward 200-300mm is provided on the top edge of the baffle plate 4, and a second horizontal baffle 43 with a width of 300-600mm is provided in the middle of the baffle plate 4 along the horizontal direction above the first section of the air curtain generating pipe 7, thereby improving the smoke collection efficiency of the suction hood 2.

[0030] The square frame on the side of the aforementioned movable support 1 away from the wind deflector 4 is in an open state and is not equipped with a baffle or the like. In addition to providing support, it also facilitates the driver to observe the environment during the pouring process.

[0031] The high-temperature flue gas capture method for non-fixed-position sand box casting according to the present invention mainly includes the following steps:

[0032] S1. After the sand box position is determined, the crane will transport the pouring ladle to the top of the sand box and prepare for pouring.

[0033] S2, the suction hood 2 is moved to the pouring position by moving the support 1;

[0034] S3, start the dust removal system and open the valve connected to the suction hood 2. At the same time, turn on the air supply fan 73 in the air curtain generating pipe 7 to form an air curtain covering the upper side of the pouring ladle.

[0035] S4. After the pouring is completed, the suction hood 2 is moved to another station by the moving bracket 1, and the crane moves the pouring ladle away at the same time.

[0036] It should be noted that in the description of this invention, terms such as "front," "rear," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to 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, they should not be construed as limitations on this invention.

Claims

1. A method for capturing high-temperature flue gas during sand casting in a non-fixed-position workstation, achieved through a flue gas capture device, characterized in that: The flue gas capture device includes: A suction hood is installed on the side above the pouring pit, and the outlet end of the suction hood is connected to the dust removal system through a sliding sealing tube mechanism. A movable support is straddling the top of the pouring pit and slidably connected to guide rails on both sides of the pouring pit. The top of the movable support is provided with an opening structure for accommodating the crane rope, and the side of the movable support is provided with a wind baffle. The wind baffle extends upward and is connected to the inlet end of the suction hood. An air curtain generating pipe is installed on the top of the movable support. The air curtain generating pipe is a U-shaped structure composed of a first section, a second section and a third section connected in sequence. The first section has an air outlet that is angled upward and opposite to the wind baffle. The third section is parallel to the first section and has a return air outlet. The second section is equipped with a blower. in, The movable support includes two square frames and a top crossbar for connecting the two. The bottom of the square frames is slidably connected to the guide rail, and the top crossbar is positioned near one end of the square frames. The bottom of the baffle plate is sealed to a square frame near the suction hood, and the top of the baffle plate is inclined toward the pouring pit and is provided with an installation port that matches the inlet of the suction hood. Vertical baffles are provided on both sides of the wind baffle, a first horizontal baffle is provided on the top edge of the wind baffle, and a second horizontal baffle is provided in the middle of the wind baffle, located above the first section of the air curtain generating pipe. The capture method includes the following steps: S1. After the sand box position is determined, the crane will transport the pouring ladle to the top of the sand box and prepare for pouring. S2, the suction hood is moved to the pouring position by moving the support; S3, start the dust removal system and open the valve connected to the suction hood. At the same time, turn on the air supply fan in the air curtain generating pipe to form an air curtain covering the upper side of the pouring ladle. S4. After the pouring is completed, the suction hood is moved to another work station by moving the support frame, and the crane moves the pouring ladle away at the same time.

2. The method for capturing high-temperature flue gas during non-fixed-position sand casting according to claim 1, characterized in that: The return air inlet is positioned directly opposite the first section of the air curtain generating pipe.

3. The method for capturing high-temperature flue gas during non-fixed-position sand casting as described in claim 1, characterized in that: The centerline of the air outlet is deflected downwards by 3°-5° along the centerline of the suction hood.

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