A grate constant temperature device for an incinerator and its grate constant temperature method

Abstract

The present invention discloses a grate constant temperature device for an incinerator and a grate constant temperature method thereof. The grate includes a plurality of grate plates arranged side by side, and there is a grate gap for primary air to pass between two adjacent grate plates. The air outlets of each primary air duct are all facing at least two groups of grate plates. Each water mist mechanism is installed inside the corresponding primary air duct and close to the air outlet. During the process of the water mist mechanism spraying water mist, it can quickly spread to the surface of the grate plates. The water mist mechanism is provided with water mist nozzles corresponding one by one to the grate plates facing the air outlets. Each water mist nozzle faces each grate plate and sprays water mist capable of covering the grate plates. After the water mist covers the surface of the grate plates, it quickly turns into water vapor and absorbs the heat on the grate plates, forming a continuous cycle of water mist contact and water vapor removal on the surface of the grate plates, improving the cooling effect on the grate plates and prolonging their service life.

Description

Technical Field

[0001] The invention relates to the technical field of incinerators, and in particular to a grate constant temperature device for an incinerator and a grate constant temperature method thereof. Background Art

[0002] In the existing garbage incinerator, the garbage is burned on the grate, and the primary air passes through the gap between the grates to provide oxygen for the garbage combustion. Due to the development of garbage classification, the calorific value of the garbage entering the furnace is gradually increased. The calorific value of the dry garbage entering the furnace is twice that of the mixed garbage before classification. The high calorific value garbage releases a lot of heat during combustion, which inevitably causes the grate to overheat, thereby reducing the service life of the grate and aggravating the wear of the grate. The traditional grate system passes the primary air through the bottom of the grate, conducts convection heat exchange with the grate, and reduces the grate temperature, which is more suitable for ordinary low calorific value garbage. For example, patent document CN102865586A discloses a novel biomass boiler rotating air-cooled grate system, wherein the rotating shaft rotates, driving the grate to rotate together, and the wind enters the primary air duct through the windshield and blows out evenly to the grate, so that the fuel combustion speed gear on it can be manually adjusted to make the grate speed slow and even, so that the fuel is evenly arranged on the grate and fully burned; secondly, the shaft and bearings are cooled by the wind to effectively reduce their own temperature, while increasing the primary air temperature, which is convenient for fuel combustion; thirdly, the air supply angle is changed through the windshield, so that the primary air is evenly blown to the grate, which is beneficial to the cooling of the grate and prevents the biomass ash from falling on the bearing and damaging the shaft and accessories. However, it is affected by its own air volume and can only be used in the incinerator of low calorific value garbage. For high calorific value garbage, the industry uses water-cooled grates, and arranges water-cooling pipes on the lower surface of the grate. Due to the complexity of the pipeline, the cost is high, and the cooling effect is limited. Summary of the invention

[0003] The purpose of the present invention is to provide a grate constant temperature device and a grate constant temperature method for an incinerator to solve the problems existing in the above-mentioned prior art. The water mist sprayed by the water mist nozzle vaporizes and absorbs heat after contacting the surface of the grate, thereby quickly reducing the grate temperature and ensuring the service life of the grate.

[0004] To achieve the above-mentioned purpose, the present invention provides the following scheme: The present invention provides a grate constant temperature device for an incinerator, comprising a plurality of water mist mechanisms and primary air ducts all arranged on the side of the grate away from the furnace, the grate comprising a plurality of grate plates arranged side by side, a grate gap for primary air to pass through is provided between two adjacent grate plates, the air outlets of each primary air duct are directly facing at least two groups of grate plates, each of the water mist mechanisms is installed on the inner side of the corresponding primary air duct and close to the air outlet, the water mist mechanisms are provided with water mist nozzles corresponding to the grate plates directly facing the air outlet, each of the water mist nozzles is respectively directed towards each of the grate plates and sprays water mist that can cover the grate plates.

[0005] Preferably, the water mist nozzle is directed at the middle position of the grate bar.

[0006] Preferably, temperature sensors for monitoring the temperature of the grate bars are provided on one side of each grate bar away from the furnace chamber, and the temperature sensors are connected to the water mist mechanism to adjust the spray amount of the water mist nozzle.

[0007] Preferably, the primary air duct includes an air inlet section and an air outlet section connected to the air inlet section, and the flow cross-section of the air outlet section is larger than that of the air inlet section.

[0008] Preferably, the air outlet section has a conical structure with a gradually expanding flow cross-section from the air inlet section to the air outlet.

[0009] Preferably, a flow-attenuating section is connected between the air outlet section and the air outlet. The flow-attenuating section has a straight cylindrical structure with a flow cross-section equal to that of the enlarged end of the conical structure, and the water mist nozzle is arranged at a position of the flow-attenuating section close to the air outlet.

[0010] Preferably, the air outlet is coaxially arranged with the flow-attenuating section, and the structure of the air outlet is equal to the flow cross-section of the flow-attenuating section.

[0011] Preferably, the air outlets are arranged side by side, and the total ventilation cross-section of the air outlets matches the grate structure.

[0012] Preferably, the air outlet includes two side edges along the arrangement direction of the grate bars. The two side edges are respectively directed at the grate gaps, and there is an air inlet interval for the primary air to enter the grate gaps between the two side edges and the grate gaps.

[0013] A method for maintaining a constant temperature of the grate is also provided, including the following steps:

[0014] Preparation before cooling: Electrically connect each temperature sensor, and monitor the temperature of each grate bar through the temperature sensor;

[0015] Air inlet conduction: Turn on the air inlet fan connected to the primary air duct, introduce the primary air into the furnace chamber through the grate bars, and adjust the power of the air inlet fan according to the temperature monitored by the temperature sensor. When the temperature of the grate bar is too high, increase the air inlet volume; when the temperature of the grate is too low, decrease the air inlet volume;

[0016] Water mist cooling: When the air inlet volume reaches a preset value and the temperature of the grate bar continues to rise, turn on the water mist mechanism. The water mist is sprayed onto the surface of the grate bar away from the furnace chamber through the water mist nozzle. The water mist quickly vaporizes into water vapor, and the water vapor is driven by the continuously introduced air flow to pass through the gaps on the grate bar and enter the furnace chamber. When the temperature of the grate bar is too high, increase the water mist amount; when the temperature of the grate is too low, decrease the water mist amount.

[0017] The present invention has achieved the following technical effects compared with the prior art:

[0018] First, the grate includes a number of grate bars arranged side by side. There are grate gaps for the primary air to pass through between adjacent grate bars. The air outlets of each primary air duct are all facing at least two groups of grate bars, so that the air outlets of the primary air ducts can be matched with corresponding grate gaps, facilitating the primary air to enter the furnace through the grate gaps, effectively providing oxygen for the furnace. Each water mist mechanism is installed inside the corresponding primary air duct and close to the air outlet. During the process of the water mist mechanism spraying water mist, it can quickly spread to the surface of the grate bars, avoiding too long spraying paths and being easily interfered by the flow of the primary air during the diffusion process. The water mist mechanism is provided with water mist nozzles corresponding one by one to the grate bars facing the air outlet. Each water mist nozzle faces each grate bar and sprays water mist that can cover the grate bars. After the water mist covers the surface of the grate bars, it quickly turns into water vapor and absorbs the heat on the grate bars. Since the speed of the primary air increases when passing through the grate gaps, a certain degree of negative pressure is formed near the grate gaps, causing the water vapor to flow towards the grate gaps on both sides of the grate bars and enter the furnace along with the primary air, forming a continuous cycle of water mist contact and water vapor removal on the surface of the grate bars, improving the cooling effect on the grate bars and extending their service life.

[0019] Second, the water mist nozzles face the middle position of the grate bars, so that the water mist sprayed by the water mist nozzles spreads from the middle position of the grate bars towards both sides, making the water mist contact the grate bars as fully as possible, cooling the grate bars sufficiently, and avoiding the water mist flowing out from the grate gaps on both sides before it has time to contact the grate bars, reducing the waste of water mist and avoiding affecting the temperature inside the furnace.

[0020] Third, the air outlet includes the two side edges along the arrangement direction of the grate bars. The two side edges respectively face the grate gaps and there is an air inlet interval for the primary air to enter the grate gaps between them and the grate gaps, enabling the primary air to not only flow into the furnace through the grate gaps corresponding to the middle position of the air outlet, but also flow into the furnace through the grate gaps corresponding to both sides of the air outlet, expanding the flow path of the primary air and ensuring the uniformity of the primary air flow, avoiding the primary air generating turbulence near the grate bars and affecting the stable diffusion of the water mist to the grate bars, and also ensuring that the edge of the air outlet no longer forms a closed structure for the water vapor, ensuring that the water vapor can quickly separate from the grate bars.

[0021] Fourth, temperature sensors for monitoring the temperature of the grate bars are provided on the side of the grate bars away from the furnace chamber. The temperature sensors are connected to the water mist mechanism to adjust the spraying amount of the water mist nozzles. Since the water mist is sprayed onto the high-temperature grate surface, the material on the side of the grate away from the furnace chamber cools down and shrinks. If this process is too intense, it is easy to cause damage to the grate material. By setting the temperature sensors, the spraying amount is controlled to keep the grate material within a reasonable temperature range and reduce the risk of grate material damage. Brief Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 Schematic diagram of the overall structure connection of the present invention;

[0024] Among them, 1 - furnace chamber, 2 - grate bars, 3 - grate gap, 4 - water mist nozzle, 5 - air outlet section, 6 - air inlet section. Detailed Embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide a grate constant temperature device for an incinerator and its grate constant temperature method to solve the problems existing in the above-mentioned prior art. The water mist sprayed by the water mist nozzle vaporizes and absorbs heat after contacting the surface of the grate bars, quickly reducing the temperature of the grate and ensuring the service life of the grate.

[0027] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0028] Please refer to Figure 1, this embodiment provides a grate constant temperature device for an incinerator, which includes a plurality of water mist mechanisms and primary air ducts all arranged on the side of the grate away from the furnace chamber 1. The grate includes a plurality of grate plates 2 arranged side by side, and there is a grate gap 3 for the passage of primary air between two adjacent grate plates 2. The air outlets of each primary air duct are all facing at least two groups of grate plates 2, so that the air outlets of the primary air ducts can be respectively equipped with corresponding grate gaps 3, facilitating the primary air to enter the furnace chamber 1 through the grate gaps 3, effectively providing oxygen for the furnace chamber 1. Each water mist mechanism is installed inside the corresponding primary air duct and close to the air outlet. During the process of the water mist mechanism spraying water mist, it can quickly spread to the surface of the grate plate 2, avoiding too long spraying paths and being easily interfered by the flow of the primary air during the diffusion process. There are water mist nozzles 4 on the water mist mechanism corresponding one by one to the grate plates 2 facing the air outlet. Each water mist nozzle 4 faces each grate plate 2 and sprays water mist that can cover the grate plate 2. After the water mist covers the surface of the grate plate 2, it quickly turns into water vapor and absorbs the heat on the grate plate 2. Since the speed of the primary air increases when passing through the grate gap 3, a certain degree of negative pressure is formed near the grate gap 3, causing the water vapor to flow towards the grate gaps 3 on both sides of the grate plate 2 and enter the furnace chamber 1 along with the primary air, forming a continuous cycle of water mist contact and water vapor removal on the surface of the grate plate 2, improving the cooling effect on the grate plate 2 and extending its service life. Further, it should be noted that when spraying water mist on the grate plate 2, during the heat exchange process, it can directly turn into water vapor, that is, a phase change occurs, ensuring the temperature reduction effect on the grate plate 2. In the prior art, when cooling the grate plate 2 through a water path, only the temperature of the water flow changes and it cannot quickly vaporize, so no phase change occurs, that is, the temperature reduction effect is not significant. Preferably, the water mist sprayed by the water mist nozzle 4 is made of pre-treated soft water.

[0029] Further, the water mist nozzle 4 is facing the middle position of the grate plate 2, so that the water mist sprayed by the water mist nozzle 4 spreads from the middle position of the grate plate 2 towards both sides, making the water mist contact the grate plate 2 as fully as possible, cooling the grate plate 2 sufficiently, and avoiding the water mist flowing out from the grate gaps 3 on both sides before it has time to contact the grate plate 2, reducing the waste of water mist and avoiding affecting the temperature inside the furnace chamber 1.

[0030] Preferably, temperature sensors for monitoring the temperature of the grate bars 2 are provided on the side of the grate bars 2 away from the furnace chamber 1. The temperature sensors are connected to the water mist mechanism to adjust the spray volume of the water mist nozzles 4. Since the water mist is sprayed onto the high-temperature grate surface, the material on the side of the grate away from the furnace chamber 1 cools down and shrinks. If this process is too intense, it is likely to cause damage to the grate material. By setting the temperature sensors and then controlling the spray volume, the temperature of the grate material can be controlled within a reasonable range, reducing the risk of damage to the grate material. Preferably, the temperature of the grate bars 2 is generally controlled between 150°C and 230°C. When the temperature of the grate bars 2 is higher than 150°C, the spray volume is increased; when the temperature of the grate bars 2 is lower than 150°C, the spraying stops.

[0031] Further, the primary air duct includes an air inlet section 6 and an air outlet section 5 connected to the air inlet section 6. The flow cross-section of the air outlet section 5 is larger than that of the air inlet section 6, so that the flue gas enters the air outlet section 5 after passing through the air inlet section 6. Since the flow cross-section of the air outlet section 5 becomes larger, the flow velocity of the flue gas is reduced, avoiding the influence of too fast flow velocity of the flue gas on the spraying effect of the water mist.

[0032] As a preferred embodiment of the present invention, the air outlet section 5 has a conical structure with a gradually expanding flow cross-section from the air inlet section 6 to the air outlet. The design of the conical structure makes the flow velocity of the flue gas change in a stepped manner, that is, gradually decrease, avoiding sudden changes in the flow cross-section of the flue gas and causing turbulence in the flow process of the flue gas, which affects the spraying effect of the water mist.

[0033] As a preferred embodiment of the present invention, a flow buffer section is connected between the air outlet section 5 and the air outlet. The flow buffer section has a straight cylindrical structure with a flow cross-section equal to that of the enlarged end of the conical structure. By setting the straight cylindrical structure, the flow buffer section can buffer the flue gas with a changing flow velocity, thereby ensuring the uniformity and stability of the flue gas flow and reducing the influence on the water mist spraying. Moreover, the water mist nozzles 4 are arranged at a position close to the air outlet in the flow buffer section to ensure that the water mist can quickly spread onto the grate bars 2. Preferably, the water mist nozzles 4 are arranged 10 - 50 cm below the grate bars 2. Further preferably, the water mist particles are less than 200 μm, so as to ensure that the water mist particles can be quickly vaporized, reducing the influence on the internal temperature of the furnace chamber 1, or even if they enter the furnace chamber 1, the small size of the water mist particles cannot cause more influence on the furnace chamber 1.

[0034] Furthermore, the air outlet is coaxially arranged with the flow-equalizing section, and the structure of the air outlet is equal to the flow cross-section of the flow-equalizing section, avoiding cross-sectional changes between the air outlet and the flow-equalizing section, which may cause turbulence in the flue gas and affect the spraying effect of the water mist. Preferably, the air outlet is close to the surface of the grate away from the furnace chamber 1. Then, during the flow of the flue gas, since the air outlet is close to the grate, the flue gas in each primary air duct can directly enter the grate gap 3 after passing through the primary air duct, avoiding interference in the flow of the flue gas between adjacent primary air ducts and further ensuring the spraying effect of the water mist in each primary air duct.

[0035] As a preferred embodiment of the present invention, the air outlets are arranged side by side, and the total ventilation cross-section of the air outlets matches the grate structure, thereby ensuring that each grate plate 2 can be sprayed with water mist to ensure the service life of each grate plate 2.

[0036] As a preferred embodiment of the present invention, the air outlet includes two side edges along the arrangement direction of the grate plates 2. The two side edges are respectively opposite to the grate gaps 3, and there is an air inlet interval for the primary air to enter the grate gaps 3 between the two side edges and the grate gaps 3. This enables the primary air to flow into the furnace chamber 1 not only from the grate gaps 3 corresponding to the middle position of the air outlet, but also from the grate gaps 3 corresponding to both sides of the air outlet, expanding the flow path of the primary air and ensuring the uniformity of the primary air flow, avoiding turbulence of the primary air near the grate plates 2, which may affect the stable diffusion of the water mist to the grate plates 2, and also ensuring that the edge of the air outlet no longer forms a closed structure for the water vapor, ensuring that the water vapor can quickly detach from the grate plates 2.

[0037] Furthermore, a method for maintaining the constant temperature of the grate is also provided, including the following steps:

[0038] Preparation before cooling: Electrically connect each temperature sensor, and monitor the temperature of each grate plate 2 through the temperature sensor;

[0039] Inlet air conduction: Open the inlet air fan connected to the primary air duct, introduce the primary air into the furnace chamber 1 through the grate plates 2, and adjust the power of the inlet air fan according to the temperature monitored by the temperature sensor. When the temperature of the grate plates 2 is too high, increase the inlet air volume; when the grate temperature is too low, decrease the inlet air volume;

[0040] Water mist cooling: When the inlet air volume reaches the preset value and the temperature of the grate plates 2 continues to rise, turn on the water mist mechanism. The water mist is sprayed onto the surface of the grate plates 2 away from the furnace chamber 1 through the water mist nozzles 4. The water mist quickly vaporizes into water vapor, and the continuously introduced air flow drives the water vapor to pass through the gaps on the grate plates 2 and enter the furnace chamber 1. When the temperature of the grate plates 2 is too high, increase the water mist volume; when the grate temperature is too low, decrease the water mist volume.

[0041] Adaptations made according to actual needs are within the protection scope of the present invention.

[0042] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0043] Specific examples are used in the present invention to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A grate constant temperature device for an incinerator, characterized in that, it includes a plurality of water mist mechanisms and primary air ducts all arranged on the side of the grate away from the furnace chamber. The grate includes a plurality of grate plates arranged side by side, and there is a grate gap for the passage of primary air between two adjacent grate plates. The air outlets of each primary air duct are all facing at least two groups of the grate plates. Each water mist mechanism is installed inside the corresponding primary air duct and close to the air outlet. The water mist mechanism is provided with water mist nozzles corresponding one by one to the grate plates facing the air outlet. Each water mist nozzle faces each grate plate respectively and sprays water mist capable of covering the grate plate; the water mist nozzle is facing the middle position of the grate plate; the air outlet includes two side edges along the arrangement direction of the grate plates. The two side edges are respectively facing the grate gaps, and there is an air inlet interval for the primary air to enter the grate gaps between the side edges and the grate gaps.

2. The grate constant temperature device for an incinerator according to claim 1, characterized in that, temperature sensors for monitoring the temperature of the grate plates are provided on the side of each grate plate away from the furnace chamber. The temperature sensors are connected to the water mist mechanism for adjusting the spray amount of the water mist nozzles.

3. The grate constant temperature device for an incinerator according to claim 2, characterized in that, the primary air duct includes an air inlet section and an air outlet section communicated with the air inlet section. The flow cross-section of the air outlet section is larger than that of the air inlet section.

4. The grate constant temperature device for an incinerator according to claim 3, characterized in that, the air outlet section has a conical structure with a gradually expanding flow cross-section from the air inlet section to the air outlet.

5. The grate constant temperature device for an incinerator according to claim 4, characterized in that, a slow flow section is communicated between the air outlet section and the air outlet. The slow flow section has a straight cylindrical structure with a flow cross-section equal to that of the enlarged end of the conical structure. The water mist nozzles are arranged at a position of the slow flow section close to the air outlet.

6. The grate constant temperature device for an incinerator according to claim 5, characterized in that, the air outlet and the slow flow section are coaxially arranged, and the structure of the air outlet is equal to the flow cross-section of the slow flow section.

7. The grate constant temperature device for an incinerator according to claim 6, characterized in that, each of the air outlets is arranged side by side.

8. A grate constant temperature method applying the grate constant temperature device for an incinerator according to any one of claims 1 to 7, characterized in that, it includes the following steps: Preparation before temperature reduction: Electrically connect each temperature sensor, and monitor the temperature of each grate plate through the temperature sensor; Conduct primary air: Open the primary air fan connected to the primary air duct, introduce the primary air into the furnace chamber through the grate plates, and adjust the power of the primary air fan according to the temperature monitored by the temperature sensor. When the temperature of the grate plate is too high, increase the air intake volume. When the temperature of the grate is too low, reduce the air intake volume; Water mist cooling: When the air intake reaches the preset value and the temperature of the grate bars continues to rise, the water mist mechanism is turned on. The water mist is sprayed onto the surface of the grate bars away from the furnace through the water mist nozzles. The water mist quickly vaporizes into water vapor, and the water vapor is driven by the continuously introduced air flow to pass through the gaps on the grate bars and enter the furnace. When the temperature of the grate bars is too high, the water mist volume is increased; when the temperature of the grate is too low, the water mist volume is decreased.

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