KR20090016546A - System for milling and air-water cooling bottom ash from heating furnaces for solid fuels - Google Patents

Abstract

The present invention relates to a milling and water-air combined cooling system for bottom ash from heating furnaces for solid fuels, able to maximize the efficiency in milling and cooling also large ash lumps at high temperature and in improving cooling air fluid dynamics which passes said system in counter-flow. The system comprises a crusher (1) provided with a pre-crusher integral with the crusher's (1) port, a water cooling system (3-4), and a separation (5-6) of the flow of the fine material entering the crusher (1) from the lump sized ash. The pre-milling device (2) allows a partial milling of the large lumps and it is actuated by laser or equivalent sensors (7) which detect the presence of ash agglomerates in the milling area. The cooling water passes preferably throughout the shaft (8) of the toothed rotor (9) and/or throughout the fixed slab (10) and moves therefrom, through suitable ducts (4) and nozzles (3), to the milling area. The water intervention is automated depending on the crusher rotor's (9) or casing's (11) temperatur detected by suitable sensors (12). The flow separation of the fine material is achieved creating an opening (13) at the rear wall of the crusher and isolating it by a counterweight or automatic valve (5) at the unloading channel (14) and a closing shield (6) downstream of the traction head of the fine ash recuperator (15).

Description

SYSTEM FOR MILLING AND AIR-WATER COOLING BOTTOM ASH FROM HEATING FURNACES FOR SOLID FUELS}

FIELD OF THE INVENTION The present invention relates to a cooling system combined with bottom ash milling and water cooling-air cooling in a furnace using solid fuel, wherein a large mass of ash at high temperatures can also maximize the milling and cooling efficiency, It improves the flowability of cooling air and liquids in countercurrent.

The system comprises a mill (1) provided with a pre-mill integrated into the port of the mill (1), a water cooling cooling system (3, 4), and a separation of the refined material flow entering the mill (1) from ash sized masses. (5, 6). The pre-milling device 2 allows partial milling of large chunks and is activated by a laser or equivalent sensor 7 which detects the presence of ash chunks in the milling area. The coolant passes appropriately through the shaft 8 and / or the fixed slab 10 of the interlocking rotor 9, from which it moves through the appropriate tubes 4 and the nozzle 3 to the milling area. The adjustment of the coolant is automatic depending on the temperature of the mill rotor 9 or casing 11 sensed by the appropriate sensors 12. Separation of the flow of the refined material is achieved by forming an opening 13 in the back of the mill, the discharge passage 14; And a closed shield 6 downstream of the discharge head of the traction head of the refined ash heat recoverer 15.

In the dry ash extraction systems, the cooling of the ash on the off-road conveyor and the conveyors to which it is connected is a depression value that occurs at the bottom of the furnace. Is performed by heat exchange accompanied by air circulation whenever an air circulation occurs. Cold air is guided through appropriate ports located next to the extractor and its associated conveyors, and ashes as they travel through the lines of counter-flow conveyor machines until they reach the combustion chamber. Blow them up). The system provides one or more milling steps between the extractor and the continuous conveyor / cooler to increase efficiency in air-reheat heat exchange. This milling system, which shrinks the ash to a very small size, increases the available area for heat exchange of countercurrent air. In a typical extraction system one of the main extractors receiving ash in the furnace and one of the continuous conveyors are provided with fine ash recuperators located at the bottom. The recovered ash is then lowered to the heavy ash masses and to the next mechanism.

Along with the rear cooling air passages associated with the device line, passing from one device to the previous device until reaching the combustion chamber is particularly dangerous in front of the mill. While being lifted back to the grinder and then to the loading hopper, air is drawn to the bottom point where the refined ash heat recovery machine is installed and draws out some of the refined material that is recovered by accumulating in the bend of the device. Such periodic trends are anomalously related to problems in wear, mechanical malfunctions, and also higher flow rate values than those designed internally, which are much more important than trends expected in normal operation. To generate a locking of the refined ash heat recovery device which is operative to generate. In order to avoid this situation, known systems are provided with a bypass tube of suitable diameter to connect the extractor top cover near the unloading point and the next conveyor cover at the downstream position associated with the discharge point. -pass duct). The purpose is to allow a differential path to provide cold air during the passage from one conveyor to the preceding conveyor, starting from the top of the ash conveyor belt. However, opening of the ash flow falling inside the mill; And a reduction in lump size made by crushing members resulting in an increase in the available forced-convection heat-exchange surface of the ash; Since only crosses the minimum amount of air, this solution greatly reduces the cooling efficiency of the ash.

Furthermore, large chunks of bottom ash generated in the furnace are cooled only by the outside air so that the interior of them can remain doughy, in which case the milling function of the grinder is a combined roller Only a few grooves are created on the ash mass which is not processed by the operation, and is very degraded. This situation causes cumulative problems in mills that require intervention to clean the port and allow general material to flow, and inevitable increases in the operating temperature of the milling elements and the mill casing and the very rapid In addition to consumption, a significant reduction in wear strength occurs.

All of these problems can maximize milling and maximize the cooling efficiency of the bottom ash even at very high temperature agglomerations, eliminating the inevitable malfunction caused by excess wear for heat recovery devices of refined materials. It is solved by the milling and cooling system according to the invention which increases the dynamic flow of cool air.

An automatic valve generally submerged in the bypass tube; Thanks to appropriate measures such as; and a separation of the refined ash discharged from the mass size ash, the dynamic flow of cool air and the air / ash heat exchange efficiency are highly improved compared to conventional systems. All air flow actually travels through the mill, and the air / ash cooling efficiency in the mill is due to the wider surface available for heat exchange that occurs due to free fall of the ash in the injected air and the mill operation. To the maximum. The separated ash of the discharged ash is discharged from the surroundings of the mill by means such as a valve located in the discharge passage and a shield closed under the discharge of the traction head of the ash ash heat recovery machine. By isolation, a dedicated opening is formed in the rear wall of the mill to which the discharge passage of the ash heat recovery device is connected. The position where the refined ash is fed into the grinder is such that the refined ash passes through the milling (machining) area and prevents dense flow from occurring and is more dispersed during free fall, and crosses in the grinder flowing in the reverse direction. Almost no mixing occurs by the cooling air.

The milling and cooling efficiency of large ash masses that are hot is maximized due to the presence of a pre-crusher and water cooling system.

The function of the pre-mill is to perform the initial milling of large ash chunks at high temperatures which obstruct the mill port and to make the milling operation of the rotor teeth faster and more efficient. The interference (actuation) of the pre-crusher is activated by a laser corresponding to a sensor that detects the presence of large ash masses entering the milling area.

Cooling water for the cooling system is appropriately provided through the foundation of the rotor shaft and / or the fixed slab, and then passes through the interlocking rotor and / or the nozzles located in the fixed slab and then in the milling zone. do. The cooling system is sensed by appropriate sensors and activated by increasing the temperature values of the toothed roller and grinder casing by detecting the presence of ash and large chunks at high temperatures. The coolant flow rate supplied to the nozzle can be controlled depending on the temperature of the ash leaving the mill and can be sensed in a downstream machine by a suitable sensor. Thanks to separating the mill surroundings from the refined ash heat recovery machine, steam generated during the cooling process is led directly to the combustion chamber by the cool air.

The configuration of this system includes: obstructions; And initial wear to the refined ash heat recoverer; a number of notable effects occur and also reduce the wear of the mill having more to process the refined material. The heat exchange efficiency between the air and the ash can reach its highest point because all cold air does not collide with the ash while (ash) falls between any conveyor unit and the next unit, and the cooling and milling process More effective cooling of the mill has also been achieved to optimize for large ash masses at high temperatures as well.

The innovative features, objects, and effects of the present invention are shown by the accompanying drawings as detailed descriptions and the following non-limiting examples, and the distinguishing features of the embodiments are as follows.

1 shows a cross-sectional view of an integrated milling and air cooling / water cooling cooling system.

Figure 2 shows the location of the integrated milling and cooling system throughout the extraction and cooling air flow system throughout the system.

3 shows a milling and air / water cooling cooling system with axonometric projection.

Continuing with this, it will be pointed out that like reference numerals on different drawings refer to the same or equivalent parts.

The milling and cooling system described below allows for a number of notable effects. Because, as a result of equipment failure and removal of excess wear in the refined ash heat recovery device and reduction of mill wear, the dynamics of the cooling air flow are improved. Since all cold air does not collide with the ash while the ash falls between any conveyor apparatus and the following apparatus, the heat exchange efficiency between the air and the ash reaches the highest point, and the cooling and milling process is performed by the mill milling member. It is also optimized for large ash masses at high temperatures by achieving more effective cooling of the field.

The system consists of one or two interlocking rollers (9), a pre-milling device (2), an air cooling (3) and a water cooling (4) cooling system, and a mass inlet ash inlet (ash inlet). It is characterized by a side inlet 13 for refined material separated from the ash inlet.

The refined ash outlets 5, 6, 13 separated from the mill 1 are suitable passages independent of the main ash outlet 16 and connected to a suitable opening 13 formed in the back of the mill 1. (channel) 14 is formed. The refined ash inlet located in the mill 1 is to avoid intersecting with the milling members 9 as it is. A counter-weight or automatic valve 5 within the refined ash discharge passage 14 is provided with an air inlet inside the heat recoverer when the refined material crosses the crusher counter-flow. It prevents inhalation and releases refined material. Furthermore, the closed shield 6 located downstream of the traction head 15 of the ashed ash heat recovery machine isolates this area from the discharge area 16 of the conveyor apparatus and the ashed ash heat recovery device. (15) Eliminate internal air recurrence. As a countermeasure, the use of a generally submerged automatic valve 17 installed in a by-pass duct through which cooling air passes throughout the mill 1 leads to maximum heat exchange of air / ash and also Wear problems and malfunction of the heat recovery system 15. The automatic valve 17 of the bypass pipe is provided only when obstruction of the grinder 1 detected by the differential pressure transmitter senses the increase in pressure at the discharge bottom of the grinder 1. Allow the passage of cooling air.

During the passage of air throughout the mill 1, free ash is used after milling the ash so that the opening of the ash flows on the injected air and on a wider surface where heat exchange is possible. Heat exchange is maximal.

The water cooling cooling system 3, 4 allows for additional cooling for hot ash masses of high temperature, and is increased due to the presence of high flow rates of large masses and / or ash at the high temperatures of the milling area and suitable sensors 12. It operates depending on the temperatures of the rotor 9 and the casing 11 sensed by them.

The water cooling system 3, 4 provides a sprinkling nozzle 3 suitably arranged within the rotor 9 and / or the fixed slab 10. Cooling water supplied through the shaft 8 of the rotor 9 and / or over the fixed slab 10 cools the ash that is introduced into the mill 1 and the appropriate ducts 4 and nozzles ( Through 3) to the milling area and at the same time helping efficient cooling of the operating members 9, 10. The adjustment of the coolant flow rate at the nozzle 3 is achieved depending on the temperature of the ash emitted from the mill 1 and sensed by an appropriate sensor 19 located at the bottom of the mill apparatus discharge.

Steam generated during the cooling process due to the separators 5, 6, 13 around the mill 1 (separated) from the ashed ash heat recoverer 15, avoids problems occurring in the heat recovery devices 15. It will be drawn by the cooling air directly into the combustion chamber.

The pre-crusher 2 is mounted on a fixed frame 21 with punches 20 made of suitable anti-wear material and connected to the port of the crusher 1. It is constituted by plates sliding toward and activated by hydraulic cylinders 22. Such a device allows the rotor 9 of the grinder 1 to be partially milled by moving them by the movement of the plates with the punch 20 when large, hot ash masses block the inlet there. Activates and speeds up the interlocking action. The adjustment of the pre-mill 2 is controlled by a laser or equivalent sensor 7 which detects the presence of large ash masses in the milling area.

In addition, the air-cooled and water-cooled cooling and milling systems according to the present invention are very large, which improves the flow of cooling gas and liquid, resulting in elimination of obstacles and obstacles of the mill 1 and the ash ash recovery device 15 that have been refined. It has a functional advantage, aids indirect cooling of the milling members 9, which increases the life expectancy of the mill 1, and also provides a convenient and fast milling of hot ash masses.

Claims (6)

In milling for bottom ash and air and water cooling systems in solid fuel furnaces to maximize efficiency, High temperature using integrated operation of the pre-crusher 2 combined with a separator port, a water cooling system 3 and 4 and a separation of the flow of refined material entering the mill from the mass size ash. Milling and cooling large ash masses, improving the flow of cooling air and liquids, and avoiding the inflow of refined material with recovered heat, allowing the mill 1 to best pass through the backflow of cooling air proportional to the ash flow Milling and air-cooling and water-cooling system for bottom ash in the furnace for solid fuel. 2. The pre-crusher (2) according to claim 1, wherein the pre-mill (2) is integrated into a port of the mill (1) formed by slabs with a punch (20), the punch is made of an anti-wear material, and the slabs are Sliding oppositely in a fixed frame 21 connected to the port of the grinder 1, the pre-crusher being activated by a hydraulic cylinder 22 and in operation of a slab with a punch 20 in the grinder 1. Milling and air-cooling and water-cooling systems for bottom ash in solid fuel furnaces, characterized by pre-milling of large ash masses blocking the inlet of the furnace. The cooling water of the water cooling system according to claim 1 is suitably passed through the shaft (8) of the interlocking rotor (9) and / or through the fixed slab (10), from which a suitable tube (4) and nozzle ( 3) Bottom ash milling and air-cooling and water-cooling systems in a furnace for solid fuel, characterized in that they are fed to the mill 1 and indirectly into the milling member 9 to move the milling zone to cool the ash. 2. The separation according to claim 1, wherein the separation of the inlets of the material reclaimed from the agglomerate ash inside the grinder 1 is achieved by an opening 13 provided in the back of the grinder 1, the opening being an outlet passage 14 ); And a plate (6) closed under the discharge of the traction head of the refined ash heat recovery device (15), and passing backflow to the cooling air in the grinder in all such places, avoiding the surrounding environment of the heat recovered purified ash. Milling and air cooling and water cooling systems for bottom ash in a furnace for solid fuel, characterized in that it allows. 3. Furnace for solid fuel according to claim 2, characterized in that the adjustment of the pre-mill 2 is controlled by a laser or equivalent sensor 7 which detects the presence of large ash masses in the milling area. Milling and air and water cooling systems for bottom ash 4. The method according to claim 3, wherein the adjustment of the nozzle 3 of the cooling water flow rate is carried out depending on the temperature of the ash exiting the grinder 1, which is sensed by a suitable sensor 19 located at the device below the grinder 1 discharge. During this, the water-cooled cooling adjustment is controlled by suitable sensors 12 which sense the temperature values of the rotor 9 and the casing 11. Milling for bottom ash and air-cooling and water-cooling in solid fuel furnaces system.

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