Sealing air system for preventing high-temperature flue gas from flushing valve

Abstract

The utility model discloses a sealing air system for preventing high-temperature flue gas from scouring a valve, which comprises a hearth, a powder conveying pipeline, a powder conveying valve, a sealing air pipeline and a sealing air valve, the output end of the powder conveying pipeline is communicated with the hearth, the powder conveying valve is arranged on the powder conveying pipeline, and the sealing air valve is arranged on the sealing air pipeline. The output end of the sealing gas pipeline is communicated with the powder conveying pipeline between the powder conveying valve and the hearth, the input end of the sealing gas pipeline is communicated with a gas source, the sealing gas pipeline is provided with a sealing gas valve, and compared with the prior art, the requirement can be met by adopting a conventional valve, the use and maintenance cost is low, and the system resistance is reduced.

Description

Technical Field

[0001] This utility model relates to the technical fields of pneumatic conveying and in-furnace desulfurization, and in particular to a sealing air system for preventing high-temperature flue gas from eroding valves. Background Technology

[0002] For boilers with positive pressure inside the furnace, the isolation valve at the connection between the pulverized coal conveying pipeline of the desulfurization system and the furnace needs to withstand the scouring of high-temperature flue gas from the furnace at about 850 to 1100°C when the system is shut down. The valve needs to be a specially made high-temperature resistant valve, or the direct scouring of high-temperature flue gas can be reduced through a complex system pipeline layout.

[0003] The drawbacks of existing technology are that the valves need to be specially designed high-temperature resistant valves, which require high-quality valve materials, are expensive and easily damaged, and have high usage and maintenance costs.

[0004] Protecting valves by mitigating direct flue gas erosion through pipeline layout requires a sufficiently large space, involves complex pipeline layout, increases system resistance, and generally lacks the necessary installation space on site. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the prior art and propose a sealing air system to prevent high-temperature flue gas from eroding valves. It can meet the requirements using conventional valves, has low operating and maintenance costs, and reduces system resistance.

[0006] To achieve the above objectives, this utility model proposes a sealing air system for preventing high-temperature flue gas from eroding valves, comprising a furnace, a pulverized coal conveying pipe, a pulverized coal conveying valve, a sealing gas pipe, and a sealing gas valve. The output end of the pulverized coal conveying pipe is connected to the furnace, and a pulverized coal conveying valve is provided on the pulverized coal conveying pipe. The output end of the sealing gas pipe is connected to the pulverized coal conveying pipe between the pulverized coal conveying valve and the furnace. The input end of the sealing gas pipe is connected to a gas source, and a sealing gas valve is provided on the sealing gas pipe.

[0007] Preferably, the powder conveying pipeline is connected to the desulfurizing agent feeding device, which includes a limestone powder silo, a screw feeder, a blower, and a Venturi injector. The input end of the screw feeder is connected to the limestone powder silo, the output end of the screw feeder is connected to the material input end of the Venturi injector, and the output end of the blower is connected to the air inlet end of the Venturi injector.

[0008] Preferably, the limestone powder silo is equipped with a heating mechanism, which includes a distribution pipe, several heat dissipation pipes and a manifold. The distribution pipe and the manifold are connected by the heat dissipation pipe, which is a serpentine pipe. The distribution pipe and the manifold are respectively provided with a heat medium inlet and a heat medium outlet extending out of the limestone powder silo.

[0009] Preferably, the limestone powder silo has a feed inlet on one side and a dust filter connected to the upper end of the limestone powder silo.

[0010] Preferably, the dust filter includes a housing, a filter element, a connecting sleeve, an air outlet, and a top cover. The connecting sleeve is provided on the inner rear end of the housing, and the filter element is provided inside the connecting sleeve. The top cover is provided on the front end of the housing and is pressed against the front end of the filter element. The air outlet is provided in the middle position of the housing inside the connecting sleeve.

[0011] Preferably, the air outlet is provided with an exhaust valve, and the air outlet at the front end of the exhaust valve is connected to the sealing gas pipe at the upper end of the sealing gas valve through a backflush pipe, and the backflush pipe is provided with a backflush valve.

[0012] Preferably, the front end of the housing is provided with a connection port that is threaded to the top cover, and the top cover is provided with a sealing head that is pressed against the front end of the filter element.

[0013] The beneficial effects of this utility model are as follows: This utility model isolates the high-temperature flue gas in the furnace from the valve by introducing sealing air. Compared with the prior art, conventional valves can meet the requirements, resulting in low use and maintenance costs and reduced system resistance.

[0014] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a sealing air system for preventing high-temperature flue gas from eroding valves according to the present invention;

[0016] Figure 2 This is a partial structural diagram of a dust filter.

[0017] In the diagram: 1-furnace, 2-powder conveying pipe, 3-powder conveying valve, 4-sealing gas pipe, 5-sealing gas valve, 6-desulfurizing agent feeding device, 7-backflush pipe, 8-backflush valve, 61-limestone powder silo, 62-screw feeder, 63-fan, 64-venturi injector, 65-heating mechanism, 66-feed inlet, 67-dust filter, 651-diverter pipe, 652-heat dissipation pipe, 653-manifold, 654-heat medium inlet, 655-heat medium outlet, 671-shell, 672-filter element, 673-connecting sleeve, 674-air outlet, 675-tightening cover, 676-exhaust valve, 677-connection port, 678-sealing top. Detailed Implementation

[0018] See Figure 1 , Figure 2This utility model discloses a sealing air system for preventing high-temperature flue gas from eroding valves, comprising a furnace 1, a pulverized coal conveying pipe 2, a pulverized coal conveying valve 3, a sealing gas pipe 4, and a sealing gas valve 5. The output end of the pulverized coal conveying pipe 2 is connected to the furnace 1, and the pulverized coal conveying valve 3 is provided on the pulverized coal conveying pipe 2. The output end of the sealing gas pipe 4 is connected to the pulverized coal conveying pipe 2 between the pulverized coal conveying valve 3 and the furnace 1. The input end of the sealing gas pipe 4 is connected to a gas source, and the sealing gas pipe 4 is provided with a sealing gas valve 5.

[0019] The powder conveying pipeline 2 is connected to the desulfurizing agent feeding device 6. The desulfurizing agent feeding device 6 includes a limestone powder silo 61, a screw feeder 62, a blower 63, and a Venturi injector 64. The input end of the screw feeder 62 is connected to the limestone powder silo 61, and the output end of the screw feeder 62 is connected to the material input end of the Venturi injector 64. The output end of the blower 63 is connected to the air inlet end of the Venturi injector 64. The screw feeder 62 achieves stable and controllable feeding. Through the cooperation of the blower 63 and the Venturi injector 64, high-speed jetting is generated to form suction and jetting conveying energy, which sprays limestone powder into the furnace 1 through the powder conveying pipeline 2, thereby improving the reliability and continuity of limestone powder addition.

[0020] The limestone powder silo 61 is equipped with a heating mechanism 65, which includes a distribution pipe 651, several heat dissipation pipes 652, and a manifold 653. The distribution pipe 651 and the manifold 653 are connected by the heat dissipation pipes 652, which are serpentine pipes. The distribution pipe 651 and the manifold 653 are respectively provided with a heat medium inlet 654 and a heat medium outlet 655 extending out of the limestone powder silo 61. Due to the characteristics of limestone, when it is damp and the moisture content is around 6%, the limestone powder is prone to agglomeration. This makes the flowability of the agglomerated limestone material poor when compressed air is used as a gas source to blow it into the circulating fluidized bed boiler, thus affecting the flue gas desulfurization effect. The heating mechanism 65 dries the damp limestone powder to avoid affecting the flue gas desulfurization effect.

[0021] The limestone powder silo 61 has a feed inlet 66 on one side, and a dust filter 67 connected to the upper end of the limestone powder silo 61.

[0022] The dust filter 67 includes a housing 671, a filter element 672, a connecting sleeve 673, an air outlet 674, and a top cover 675. The connecting sleeve 673 is provided on the inner rear end of the housing 671, and the filter element 672 is provided inside the connecting sleeve 673. The top cover 675 is provided on the front end of the housing 671 and is pressed against the front end of the filter element 672. The air outlet 674 is provided in the middle of the housing 671 inside the connecting sleeve 673. When the filter element 672 is replaced or maintained, the filter element 672 can be removed simply by unscrewing the top cover 675, which makes disassembly and assembly convenient.

[0023] The air outlet 674 is equipped with an exhaust valve 676. The air outlet 674 at the front end of the exhaust valve 676 is connected to the sealing gas pipe 4 at the upper end of the sealing gas valve 5 through the backflush pipe 7. The backflush pipe 7 is equipped with a backflush valve 8. The filter element 672 is backflushed and cleaned through the backflush pipe 7, thereby improving the filtration efficiency of the filter element 672 and reducing the amount of manual labor.

[0024] The front end of the housing 671 is provided with a connection port 677 that is threadedly connected to the top cover 675. The top cover 675 is provided with a sealing head 678 that is pressed against the front end of the filter element 672, which facilitates the disassembly and assembly of the top cover 675 and ensures good fixing reliability.

[0025] The working process of this utility model:

[0026] This utility model discloses a sealing air system for preventing high-temperature flue gas from eroding valves. During operation, the sealing air valve 5 and the powder conveying valve 3 are interlocked. When the desulfurization system in the furnace stops running, the closing signal of the powder conveying valve 3 is transmitted to the sealing air valve 5, causing it to open. A continuous supply of air with a pressure higher than the furnace back pressure is input into the powder conveying pipe 2 at the output end of the powder conveying valve 3, isolating the powder conveying valve 3 from the high-temperature flue gas in the furnace, thereby protecting the powder conveying valve 3 from being eroded by the high-temperature flue gas. When the desulfurization system in the furnace starts running, the opening signal of the powder conveying valve 3 is transmitted to the sealing air valve 5, causing it to close. This ensures that the two systems operate alternately without interfering with each other, and the powder conveying valve 3 is always in a state of isolation from the high-temperature flue gas.

[0027] When the filter element 672 is backflushed, the feeding into the limestone powder silo 61 stops, the sealing gas valve 5 and the exhaust valve 676 are closed, and at the same time the powder conveying valve 3 and the blower 63 are in the open state. The backflushing valve 8 is opened, and the air source enters the filter element 672 through the sealing gas pipe 4 at the input end of the sealing gas valve 5, the backflushing pipe 7 and the air outlet 674 at the input end of the exhaust valve 676. Then it passes through the filter element 672 and enters the housing 671, realizing the backflushing of the filter element 672.

[0028] The powder conveying valve 3 can be made of conventional valves, which has low operating and maintenance costs.

[0029] There is no need for complex pipeline designs to reduce the direct impact of flue gas on valves, saving installation space and pipeline costs, and reducing system resistance.

[0030] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the protection scope of the present invention.

Claims

1. A seal air system for avoiding high temperature flue gas impingement on a valve, characterized by: It includes a furnace (1), a powder conveying pipe (2), a powder conveying valve (3), a sealing gas pipe (4), and a sealing gas valve (5). The output end of the powder conveying pipe (2) is connected to the furnace (1). The powder conveying pipe (2) is equipped with a powder conveying valve (3). The output end of the sealing gas pipe (4) is connected to the powder conveying pipe (2) between the powder conveying valve (3) and the furnace (1). The input end of the sealing gas pipe (4) is connected to a gas source. The sealing gas pipe (4) is equipped with a sealing gas valve (5).

2. A seal air system for avoiding high temperature flue gas impingement on a valve as defined in claim 1, characterized in that: The powder conveying pipeline (2) is connected to the desulfurizing agent feeding device (6). The desulfurizing agent feeding device (6) includes a limestone powder silo (61), a screw feeder (62), a blower (63), and a venturi injector (64). The input end of the screw feeder (62) is connected to the limestone powder silo (61), the output end of the screw feeder (62) is connected to the material input end of the venturi injector (64), and the output end of the blower (63) is connected to the air inlet end of the venturi injector (64).

3. A seal air system for avoiding high temperature flue gas impingement on a valve as defined in claim 2, characterized in that: The limestone powder silo (61) is equipped with a heating mechanism (65), which includes a distribution pipe (651), several heat dissipation pipes (652) and a manifold (653). The distribution pipe (651) and the manifold (653) are connected by the heat dissipation pipes (652). The heat dissipation pipes (652) are serpentine pipes. The distribution pipe (651) and the manifold (653) are respectively provided with a heat medium inlet (654) and a heat medium outlet (655) extending out of the limestone powder silo (61).

4. A seal air system for avoiding high temperature flue gas impingement on a valve as defined in claim 2, characterized in that: The limestone powder silo (61) has a feed inlet (66) on one side and a dust filter (67) connected to the upper end of the limestone powder silo (61).

5. A seal air system for avoiding high temperature flue gas impingement on a valve as defined in claim 4, characterized in that: The dust filter (67) includes a housing (671), a filter element (672), a connecting sleeve (673), an air outlet (674), and a top cover (675). The connecting sleeve (673) is provided on the inner side of the rear end of the housing (671). The filter element (672) is provided inside the connecting sleeve (673). The top cover (675) is provided on the front end of the housing (671) and is pressed against the front end of the filter element (672). The air outlet (674) is provided in the middle position of the housing (671) inside the connecting sleeve (673).

6. A seal air system for avoiding high temperature flue gas impingement on a valve as defined in claim 5, characterized in that: The air outlet (674) is provided with an exhaust valve (676). The air outlet (674) at the front end of the exhaust valve (676) is connected to the sealing gas pipe (4) at the upper end of the sealing gas valve (5) through the backflush pipe (7). The backflush pipe (7) is provided with a backflush valve (8).

7. A seal air system for avoiding high temperature flue gas impingement on a valve as defined in claim 5, characterized in that: The front end of the housing (671) is provided with a connection port (677) that is threadedly connected to the top cover (675), and the top cover (675) is provided with a sealing top head (678) that is pressed against the front end of the filter element (672).

Images