Patent Application
20120240870
1. Field of Invention
The present invention relates to a gas-solid separator of circulating fluidized bed boiler as one of the key components thereof, wherein the gas-solid separator does not require any specific installing device or separating component to incorporate with the fluidized bed boiler, wherein the gas-solid separator is configured to have a first flue channel, a second flue having a fume direction different from a fume direction of the first flue channel, and an expanded cornering channel, and a collecting chamber, wherein the gas-solid separator is integrally formed at a space adjacent to a heat surface of the boiler to form an inertia-gravity gas-solid separator. In particular, the novel gas-solid separator is designed and is adapted to incorporate with different types of circulating fluidized bed boiler or other chain combustion boiler for energy saving and emission reduction.
2. Description of Related Arts
A circulating fluidized bed boiler combustion is a combustion technology having the benefits of highly adaptability, high combustion efficiency, low emission of nitric oxides, high efficiency of removing sulfur in a simple manner, and high efficiency of achieving during combustion and load regulation. Therefore, the circulating fluidized bed boiler is considered as one of the “clean” boiler to control pollutant emissions.
The boiler is one of the important thermal power equipments in a country, wherein the boiler is widely used in electrical industry, mechanical industry, metallurgic industry, chemical industry, textile industry, food industry, commercial heating industry, etc., wherein the boiler is extremely important in human lives.
Statistics show that China used 2.58 billion tons of coal in 2007, wherein the boiler used 2.2 billion tons of coal, which was 85.3% of the total coal usage. China is the number one spot for the world's most sulfur dioxide emitting country for many years. Energy saving and environmental friendly issue are included in the fundamental national policies in China. In particular, the construction of the coal type boilers is the number one project of the top ten energy-saving lists in China. According to the energy sustainable development in China, coal as the major fuel cannot be simply replaced in the coming decades, such that China is searching a feasible plan to reduce the carbon emission and to save energy in economy and industry. Therefore, the development of the existing boiler and the improvement the boiler combustion technology will be the major breakthrough in response to global climate change policies and practices.
Unlike the existing boiler, the circulating fluidized bed boiler has the advantages of desulfurization, denitrification, and energy-saving. It will be the significant influence with the reduction of energy consumption in the world when the technology of the circulating fluidized bed boiler can be further improved. The circulating fluidized bed boiler not only has the advantage of high coal adaptability but also has an unique advantage for biomass power generation and power generation from municipal solid waste incineration. In addition, the circulating fluidized bed boiler not only has the advantages of the traditional industrial boiler but also has the advantage of new energy generation.
The circulating fluidized bed gas-solid separator is the key component of the circulating fluidized bed boiler, wherein the gas-solid separator is arranged to separate solids from a large amount of high temperature incoming mixture of gas and solid particles and to return the gas back to the air chamber. The gas-solid separator also maintains the combustion chamber in a rapid fluidization manner and ensures the fuel and desulfurizer being kept cycling to repeatedly combust and react, so as to achieve the desired efficiency of combustion and desulfurization. In other words, the gas-solid separator will directly affect the performance of the circulating fluidized bed boiler. Generally speaking, the operation mode and the service life span of gas-solid separator are the sign to indicate the performance of the circulating fluidized bed boiler. Therefore, the performance of the circulating fluidized bed boiler will depend on the performance of the gas-solid separator while the developmental milestone of the circulating fluidized bed boiler will depend on the development of the gas-solid separation technology.
Currently, the most popular gas-solid separator being utilized in domestic and international markets is the high temperature cyclone type of separator which has a major advantage of high separation efficiency rate. On the other hand, the high temperature cyclone type of separator has the following disadvantages of bulky size, high wind velocity and high resistance at the tangent air inlet, and high electrical consumption of the induced fan. The high speed flue gas with gas and solid particles will carry a large amount of fly ash when the flue gas flows at the opposite direction of the collecting chamber. The concentration of the original fume emission is relatively high. The separator requires inner and outer heat insulation layers and requires relatively large amount of wear-resistant and high temperature resistant materials for construction, so as to not only highly increase the raw material cost, the manufacturing cost, and the installation cost of the separator. In addition, the separator has high thermal inertia and high temperature coke formation, and will cause the slow startup and shut down of the boiler. Some boilers unitizes the cooled water or cooled air type separator to minimize the use of wear-resistant and high temperature resistant materials and to reduce the thermal inertia, such that the coke formation within the boiler will be reduced and the boiler can be started and shut down quickly. However, the problems of high wind velocity, and high resistance at the tangent air inlet, and high electrical consumption of the induced fan are unsolved. The separation efficiency and the stability of the cooled water or cooled air type separator is lower than those of the separators made of high temperature resistance material. The manufacturing process of the cooled water or cooled air type separator is relatively complicated and the cost thereof is relatively high. Therefore, the cooled water or cooled air type separator is hard to be accepted in the existing market.
Although China Patent Application number 200910308160.1 discloses the gas-solid separator of the circulating fluidized bed boiler has many advantages compared to the high temperature cyclone type separator, such as low wind resistance, low electrical consumption, utilization of water-cooled membrane wall structure to reduce the use of wear-resistant and high temperature materials. However, the gas-solid separator has several drawbacks. For example, there is no blockage at the inlet and outlet of the turning channel. Firstly, the inertial separation performance is poor. Secondly, there is no water-cooled wall structure provided at two sidewalls of the collecting chamber such that the service life span of the separator will be shortened and the maintenance cost of the separator will be highly increased. Thirdly, the integration of the separator into the boiler structure is relatively difficult and the separator is not compatible with the geometric configuration of the boiler so as to limit the usage expansion for a large scale of boiler.
The invention is advantageous in that it provides a gas-solid separator for circulating fluidized bed boiler to solve the existing technical problems thereof, in order to save energy, to reduce energy loss, to significantly reduce the emission, to expanse the applicable range, to enhance he advanced combustion technology, to significantly save the material use, and to greatly improve the performance of the gas-solid separator as well as the boiler incorporating with the gas-solid separator.
According to the present invention, the foregoing and other objects and advantages are attained by a gas-solid separator incorporated with a circulating fluidized bed boiler without any installing device or separating component, wherein the gas-solid separator does not require any non-boiler heating surface made of wear resistant and high temperature resistant material for the cyclone type separator and does not require any non-boiler heating surface separating component made of special steel for various inertial separator. The gas-solid separator of the present invention is located at the inherent heating compartment adjacent to the heating surface of the boiler to form an inertial gravity separator, wherein the gas-solid separator is arranged to efficiently proceed the gas-solid separation through the dramatically change of the flue direction, the deceleration of the flue speed at the expanded cornering channel, and the understanding the flow pattern and speed to detour and regulate the flue direction and speed.
The gas-solid separator comprises a first flue channel, a second flue channel, an expanded cornering channel, and a collecting chamber which are located at a separator space between the rear wall of the boiler furnace and the front wall of the vertical tunnel, wherein the separator space is configured to be concealed by a film type water-cooled wall or water cooled wall made of heat resistant material. The flow of flue at the first flue channel, the second flue channel, the expanded cornering channel is regulated at different flow rates in order to increase the flow rate of flue at the first flue channel, to reduce the flow rate of flue at the expanded cornering channel, to enhance the inertial separation force and gravitational precipitation force of the solid particles, and to reduce the flow rate at the second flue channel for minimizing the solid particles being dragged by the flow of flue at the second flue channel. Therefore, the fine solid particles will not be dragged again into the flue when the flow of flue is guided along the second flue channel.
The flue with fine solid particles is guided by the film divider to detour the flue direction from the flue outlet of the boiler furnace to the first flue channel. Preferably, the flue direction at the boiler furnace is vertically upward direction and the flue direction at the first flue channel is vertically downward direction, such that the flue direction is rapidly turned 180° from the boiler furnace to the first flue channel. In particular, the flue is forced to rapidly straight down along the first flue channel to the collecting chamber. The high concentrated solid particles are initially separated from the flue by the effects of the centrifugal force generated by the sharp turning direction and the gravitational pulling force. Thus, the efficiency of inertial gravity separation for the gas-solid separation will be further enhanced by the flow propelling force and the gravitational force of the solid particles to rapidly drop the solid particles into the collecting chamber. Since the cross section of the expanded cornering channel is larger than, preferably three times larger, the cross section of the first flue channel, the flow rate of the flue will be dramatically reduced when entering to the expanded cornering channel. Therefore, the solid particles in the flue at the slow flow rate will be substantially precipitated into the collecting chamber by gravity. Accordingly, the flue direction of flue is rapidly turned at the gas-solid separator two times, preferably two 180° sharp turns, to separate the solid particles from the flue by inertial separation so as to precipitate the solid particles at the collecting chamber. The flue will also multiply strike against the even flow distributing tube sets to separate the solid particles from the flue by inertial separation so as to precipitate the solid particles at the collecting chamber. Preferably, the flow rate of flue at the first flue channel is equal or lesser than 3 m/s, such that the dragging force of the flue at the second flue channel will have minimum effect to drag the solid particles back from the collecting chamber to the second flue channel. In addition, the path length of the first flue channel, the second flue channel, the expanded cornering channel, and the collecting chamber matches with the height of the boiler furnace for prolonging the combustion time of the flue, such that the flue with the minimum solid particles has no circulating combustion value when the flue exhausts at the second flue channel.
To improve the above mentioned existing combustion technology for overcoming the shortcomings thereof, the present invention provides a novel gas-solid separator and a boiler with the novel gas-solid separator.
According to the present invention, the gas-solid separator, for a circulating fluidized bed boiler, comprises a film divider, a first flue channel, a second flue channel, a cornering channel, and a collecting chamber, wherein a flue inlet is provided at the front upper portion of the gas-solid separator, wherein a flue outer is provided at the rear upper portion of the gas-solid separator. The film divider is formed at the separator space to divide the separator space into the first flue channel and the second flue channel, wherein the first flue channel is communicated with the second flue channel through the cornering channel, wherein the bottom portion of the cornering channel is operatively linked to and sealed with the collecting chamber, wherein the bottom portion of the collecting chamber is operatively linked to the dipleg via the feedback valve.
In accordance with another aspect of the invention, the present invention comprises a boiler which comprises a boiler furnace, a gas-solid separator, and a vertical tunnel, wherein the flue inlet of the gas-solid separator is operatively linked to the upper portion of the boiler furnace while the flue outlet of the gas-solid separator is operatively linked to the upper portion of the vertical tunnel, wherein the dipleg is operatively linked to the bottom portion of the boiler furnace.
In accordance with another aspect of the invention, the present invention comprises a gas-solid separation method which comprises the steps of configuring three flowing paths as the first flue channel, the second flue channel, and the cornering channel, regulating different flow rates of the flue at the three flowing paths, increasing the flow rate of flue at the first flue channel, expanding a flow area of the expanded cornering channel with respect to the first flue channel to decelerate the flow rate of flue at the expanded cornering channel so as to enhance the inertial separation force and gravitational precipitation force of the solid particles within the flue, and minimizing said flow rate at the second flue channel for minimizing the solid particles being dragged by the flow of flue at the second flue channel. Therefore, the fine solid particles will not be dragged again into the flue when the flow of flue is guided along the second flue channel. The film divider is arranged for guiding said flue with solid particles to detour the flue direction from the flue outlet of the boiler furnace to the first flue channel. Preferably, the flue direction at the boiler furnace is vertically upward direction and the flue direction at the first flue channel is vertically downward direction, such that the flue direction is rapidly turned 180° from the boiler furnace to the first flue channel. In particular, the flue is forced to rapidly straight down along the first flue channel to the collecting chamber at the bottom portion of said cornering channel. Since the cross section of the expanded cornering channel is larger than the cross section of the first flue channel, the flow rate of the flue will be dramatically reduced when entering to the expanded cornering channel. Therefore, the high density of solid particles in the flue at the slow flow rate will be substantially precipitated into the collecting chamber by gravity. Accordingly, the flue direction of flue is rapidly turned at the gas-solid separator twice, preferably two 180° sharp turns, to separate the solid particles from the flue by inertial separation so as to precipitate the solid particles at the collecting chamber.
The present invention further contains the following distinctive features.
The gas-solid separator further comprises an even flow distributing tube set defined at the bottom portion of the film divider.
The even flow distributing tube set is provided at the cornering channel, wherein the even flow distributing tube set can provide at one side or two sides of the film divider to form the flue inlet and/or the flue outlet of the cornering channel. The upper portion of the even flow distributing tube set is operatively linked to the film divider while the bottom portion of the even flow distributing tube set is operatively linked to either the collecting chamber bottom transverse tube collecting box or the tube set bottom transverse tube collecting box within the cornering channel, wherein the collecting chamber bottom transverse tube collecting box is operatively linked to the down flowing duct of the boiler.
The film divider is configured to form the single row tube set, wherein the bottom portion of the single row tube set of the film divider is bifurcated to form a front row tube set having two or more rows of tube sets, and a rear row tube set having two or more rows of tube sets. The front and rear rows tube sets are evenly extended above the collecting chamber to form the flue inlet and flue outlet of the cornering channel. In addition, the front and rear rows tube sets are also formed as the even flow distributing tube sets at the flue inlet and flue outlet of the cornering channel. The front row tube set is frontwardly and inclinedly extended to the rear wall of the boiler furnace. The multiple rows of the front row tube set will be merged into a single row and will be vertically bent to form a front vertical tube set. The rear row tube set is rearwardly and inclinedly extended to the front wall of the vertical tunnel. The multiple rows of the rear row tube set will be merged into a single row and will be vertically bent to form a rear vertical tube set. The bottom portion of the rear vertical tube set is inwardly bent to further rearwardly extend that the bottom portion thereof is operatively linked to the collecting chamber bottom transverse tube collecting box. The bottom portion of the rear vertical tube set forms the inclined tube set as the collecting chamber tube wall, such that the collecting chamber tube wall is integrally formed with the rear vertical tube set.
The gas-solid separator further comprises a film bottom transverse tube collecting box at the bottom portion of the film divider, wherein the film divider is operatively linked to the film bottom transverse tube collecting box. The gas-solid separator further comprises a film upper transverse tube collecting box at the upper portion of the film divider, wherein the film divider is operatively linked to the film upper transverse tube collecting box. The upper portion of the even flow distributing tube set within the cornering channel is operatively linked to the film bottom transverse tube collecting box.
The upper portion of the even flow distributing tube set at the flue outlet of the second flue channel is operatively linked to the film upper transverse tube collecting box or the upper transverse tube collecting box at the upper side of the gas-solid separator. The upper transverse tube collecting box is operatively linked to the fuel guiding duct of the boiler. The bottom portion of the even flow distributing tube set at the flue outlet of the second flue channel is biased against the front wall of the vertical tunnel or the bottom portion of the even flow distributing tube set is spaced apart from the front wall of the vertical tunnel to form a downwardly vertical tube set. The bottom portion of the downwardly vertical tube set is inwardly bent to form the inclined tube set as the collecting chamber wall tube. The inclined tube set of the collecting chamber wall tube is operatively linked to the collecting chamber bottom transverse tube collecting box.
The film divider is formed at the separator space at a position according to the need of the boiler. The film divider can be provided at the middle of the rear wall of the boiler furnace and the front wall of the vertical tunnel, or the film divider can be either located slightly close to the rear wall of the boiler furnace or located significantly close to the rear wall of the boiler furnace.
Accordingly, when the flow rate of the flue at the first flue channel is greater than 5 m/s, the wear resistant connecting tube is used for the even flow distributing tube set at the cornering channel.
The film divider and the four surrounding walls of the gas-solid separator can be a full membrane wall structure, a half membrane wall structure, a partial membrane wall structure, a full light tube heat resistant drywall structure, or a heat resistant drywall structure.
The interior and/or exterior shape of the gas-solid separator can be rectangular, square, circular, oval, or polygonal shape.
The front wall of the gas-solid separator is integrally formed at the rear wall of the boiler furnace, or is an individual film membrane wall structure or a water cooled wall structure. The rear wall of the gas-solid separator is integrally formed at the front wall of the vertical tunnel, or is an individual film membrane wall structure or a water cooled wall structure. The two sidewalls of the gas-solid separator are two symmetrical film membrane wall structures or two symmetrical water-cooled walls, wherein the upper and bottom portions of the sidewalls are extended from the two symmetrical upper longitudinal tube collecting boxes to the two symmetrical bottom longitudinal tube collecting boxes. The upper symmetrical longitudinal tube collecting boxes are linked to the fuel guiding duct of the boiler. The bottom longitudinal tube collecting boxes are linked to the down flowing duct of the boiler.
The objectives of the present invention are that: the present invention provides revolutionary formation of the gas-solid separator in all fields, wherein the present invention not only contains advanced technology but also simplifies the manufacturing process of the gas-solid separator to the boiler. It, can significantly save energy, reduce flue emission, improve the overall energy efficiency, prolong the service life span of the boiler, and provide many other breakthrough in configuration of the gas-solid separator. The present invention can solve two problems of high temperature coke formation by the low burning point of the biomass and municipal solid waste and the high temperature corrosion of the boiler, such that the development of the present invention is the first objective in the new energy industry. In particular, the average circulating rate of the gas-solid separator is lesser than 5 m/s, which is a low flow resistance, and is at least 4 times lesser than the conventional cyclone type separator, wherein the motor fan can save 10% to 30% of electrical consumption when incorporating with the present invention. Therefore, the second objective of the present invention is to save energy in long term. The front wall of the gas-solid separator is integrally formed at the rear wall of the boiler furnace while the rear wall of the gas-solid separator is integrally formed at the front wall of the vertical tunnel. In other words, the material of the front and rear walls of the gas-solid separator can be significantly saved no matter how big is the boiler. Therefore, the gas-solid separator will not require two sidewalls and the film divider to fit any size of the boiler. On the other hand, the conventional cyclone type separator is an individual separator that the number of the conventional cyclone type separator will be increased when a bigger size of boiler is used. According to the present invention, the material use of the gas-solid separator is about the same or even lesser than the material use of the conventional cyclone type separator. One of the conventional cyclone type separators can be used in the boiler while the rest of the conventional cyclone type separators can be replaced by the gas-solid separators of the present invention. In other words, the more the conventional cyclone type separators are used in the boiler, the less the material use for the boiler can be reduced by replacing the conventional cyclone type separators by the present invention. The gas-solid separator of the present invention utilizes the water cooled wall structure for inertial separation such that the wear resistant treatment will only be applied 30% of the total area of the first flue channel, wherein the thickness of the wall of the first flue channel is about 50 mm and the flue rate at the first flue channel is about 7 m/s. However, the wear resistant treatment will be applied 100% of the total area of the conventional cyclone type separator, wherein the wall thickness of the conventional cyclone type separator is about 300 mm to 500 mm for heat insulation. The most thickness of the wall of the conventional cyclone type separator can be 800 mm. the flow rate is about 25 m/s for the conventional cyclone type separator. It is obvious that the material use and the wear resistant difference between the conventional cyclone type separator and the gas-solid separator of the present invention. Therefore, by significantly reducing the material use for wear resistance and heat insulation, the overall weight of the present invention will be substantially reduced to minimize the stainless steel made supporting frame for frame support. In other words, the third objective of the present invention is to minimize the material use of the gas-solid separator. Preferably, the flue direction is rapidly turned 180° from the flue outlet of the boiler furnace to the first flue channel toward the collecting chamber. In particular, the flue direction of flue is rapidly turned at the gas-solid separator two times, preferably two 180° sharp turns, to separate the solid particles from the flue by inertial separation, while the flue flow will also multiply strike to the multiple row tube sets to separate the solid particles from the flue by inertial separation. The flue rate at the first flue channel is about 5 m/s to 7 m/s and dramatically changes to 1.5 m/s to 2.5 m/s at the expanded cornering channel, such that the deceleration of the flow rate of the flue at the expanded cornering channel will effectively precipitate the solid particles in the flue at the collecting chamber by means of inertial gravity. Since the flow rate at the cornering channel is smaller than the flow rate at the second flue channel, the flue flow will not create any vortex like motion at the cornering channel while the solid particles in the flue can be further precipitated downward when the flue is guided to flow at the second flue channel. The flow rate at the second flue channel is equal or lesser than 3 m/s such that the fine solid particles will not be significantly carried by the flue at the second flue channel. The concentration of flue emission is expected close to that of the chain combustion boiler that the present invention can reach the national environmental emission standards. Therefore, the fourth objective of the present invention is to provide the gas-solid separator having relatively high gas-solid separation efficiency comparing with the conventional cyclone type separator. The first flue channel, the second flue channel, and the expanded cornering channel form a combustion chamber for complete combustion, such that the present invention will substantially add an additional combustion chamber matching the height of the boiler furnace for prolonging the combustion time of the flue. Therefore, the fifth objective of the present invention is to minimize the amount of solid particles and the carbon content in the flue. The present invention has an advanced technology and no complicated or irregular component, and is suitable for a boiler ≧35 T, wherein the gas-solid separator, the ceiling of the boiler, and the vertical tunnel can be configured to have a full membrane wall structure or water cooled non-drywall structure. Thus, the maintenance of the gas-solid separator and the boiler is simple to prolong the service life span of the gas-solid separator and the boiler. The startup and shut off response time for the boiler is quick, there is no coke formation in the boiler, and the load regulation is selectively adjustable. These features are the sixth advantage of the present invention. The seventh advantage of the present invention is to substantially reduce the solid particles in the flue, to reduce the ash accumulation at the exit of the boiler, to minimize the wear and tear of the boiler, to enhance the ash cleaning process of the boiler, to enhance the heat transfer efficiency, to save energy at different view points, and to enhance the overall performance of the boiler. The gas-solid separator can be integrated with the boiler as part of the boiler's structure to completely change the existing large scale circulating fluidized bed boiler design which is the modularization or enlargement design, such that the present invention is adapted to reduce the operation cost of the boiler and to lower the material cost and manufacturing cost of the boiler. Therefore, the eighth objective of the present invention is to enhance the development of the large scale circulating fluidized bed boiler and to create a competitive boiler structure for the power generation system in the market and the large scale coal powered power plant.
According to the present invention, the path length of the first flue channel, the second flue channel, and the expanded cornering channel, form an combustion chamber matching with the height of the boiler furnace for prolonging the combustion time of the flue, so as to solve the thermal efficiency of the boiler with <351 due to the limited height of the boiler. Especially for the transverse double drum type boiler with <35 T, the full water cooled wall type separator increases the heating surface thereof and configures the location of the heating surface, such that the present invention can utilize the space in height of the boiler for regulating the flow rate of flue and the flow path of the flue, and for increasing the flow rate of flue at the returning path. For the boiler with low steam temperature, the boiler can be configured to have an air preheating device to omit the vertical tunnel and the coal economizer. For the boiler with high steam temperature, the vertical tunnel can be configured in half size. The gas-solid flue is guided to flow upward along the convection tube set to minimize the solid particles or ash being accumulated at the convection channel and the heating surface. The average flow rate of flue at the gas-solid separator is relatively low and the gas-solid separator can precisely control and regulate the flow direction of the flue, the flow rates of the flue at different channels and the angle of the divider within the convection channel, such that the concentration of flue emission can reach the national emission standards for environmental protection. The advantages of the present invention are to significantly improve the performance of the small boiler, to solve the investment and economic drawbacks of the exiting boilers, and to provide an energy saving and environmental friendly boiler as a replacement of the conventional chain combustion boiler.
The present invention is significantly suitable for the boiler with high circulating rate. Since the large scale boiler has relatively bigger interior room to configure the cornering channel in order to provide enough space for the expanded cornering channel. The goal of the present invention can be simply achieved by selectively regulating the flow rates of flue at the first and second flue channels and the depth of the cornering channel. The path of the flow of flue from the first flue channel to the second flue channel through the cornering channel is configured as the entire space of the combustion chamber to minimize the solid particles or ash content in the flue, such that the flue with the minimum solid particles has no circulating combustion value when the flue exhausts at the second flue channel. When the flow rate of flue at the second flue channel is relatively high, a two-step low temperature cyclone separator can be setup at the vertical tunnel at a position away from the dipleg with respect to the inclination angle thereof to enable the bottom portion of the dipleg communicating with rear portion the feedback valve or the rear upper portion of the feedback valve. Since the one-step low temperature cyclone separator has higher efficiency, the two-step low temperature cyclone separator has relatively low separation efficiency to affect the combustion temperature of the boiler furnace by the low temperature separator. Therefore, the concentration of flue emission of the present invention is expected close to that of the chain combustion boiler that the present invention can reach the national environmental emission standards to provide a breakthrough in low flue emission.
It is obvious that the inertial separator of the circulating fluidized bed boiler cannot be simply replaced by the high temperature cyclone separator even though the chamber size of the boiler is larger than the size of the high temperature cyclone separator. It is because the larger drum wall of the high temperature cyclone separator must be thickened by the wear resistant and high thermal insulated material and the distance between the inlet and the outlet of the high temperature cyclone separator is limited. The present invention provides the unique features of the front wall of the gas-solid separator is integrally formed at the rear wall of the boiler furnace, the rear wall of the gas-solid separator is integrally formed at the front wall of the vertical tunnel the front row convection tube set, and the prolonged path of the flue from the first flue channel to the second flue channel through the expanded cornering channel to reduce the temperature of the boiler. Therefore, the present invention can substantially replace the high temperature cyclone separator by simply regulating the flow direction of the flue, by regulating the flow rates at different channels, and adjusting the size of the expanded cornering channel. Accordingly, the present invention provides significantly advantages to save electrical energy, to reduce the wear resistant material use, to minimize the solid particles or ash-carbon content, to lower the concentration of flue emission, to lower the wear and tear of the boiler, to extend the service life span of the boiler, to enhance the gas-solid separation efficiency, to reduce the coke formation, and to enhance the rapid startup and shut off operation of the boiler. The features of energy saving and low emission of the present invention do not depend on its size. Therefore, the present invention can incorporate with different types of boilers.
The present invention is operated according to the principle of inertial separation, in response to the flow rate of flue at 3-5 m/s for natural precipitation, to the substantial area expansion of the cornering channel for gravitational precipitation, to the flow rate equals or smaller than 5 m/s for preventing the wear and tear of the heating surface, to the flow rate equals or smaller than 3M for minimizing the drag of the fine solid particles, and to the flow rate equals or smaller than 1.5M for preventing the drag of the fine solid particles. The present invention not only fulfills the above principles but also is adapted to facilitate the full and effective implementation. The present invention is not limited by the above data and is adapted to be selectively adjusted practically according to different data and situations. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
Additional advantages and features of the invention will become apparent from the description which follows, and may be realized by means of the instrumentalities and combinations particular point out in the appended claims.
The operation process of the first embodiment is that: the fluidized bed combustion is to combust the fuel in a fluidized state, wherein the fuel can be fossil fuel, industrial and agricultural waste, municipal solid waste or various low grade fuels, biomass combustion or a combustion mixture of biomass and coal. The heavy particles will be combusted at the bottom portion of the boiler furnace 1 while the fine particles will be combusted at the upper portion of the boiler furnace 1. The fine solid particles will be blown to the flue outlet 10 and guided by the film divider 9 such that the flue direction is detoured from the upper portion of the boiler furnace 1 to the first flue channel. Preferably, the flue direction at the boiler furnace 1 is vertically upward direction and the flue direction at the first flue channel is vertically downward direction, such that the flue direction is rapidly turned 180° from the boiler furnace 1 to the first flue channel. In particular, the flue is forced to rapidly straight down along the first flue channel 8 to the collecting chamber 21. The high concentrated solid particles are initially separated from the flue by the effects of the centrifugal force generated by the sharp turning direction and the gravitational pulling force. Thus, the efficiency of inertial gravity separation for the gas-solid separation will be further enhanced by the flow propelling force and the gravitational force of the solid particles to rapidly drop the solid particles into the collecting chamber. When the flue passes through the flue inlet 6 of the cornering channel, the flue will strike against the front-outer row tube set 30 and the front-inner row tube set 31, such that solid particles will hit twice thereat and will drop at the collecting chamber 21 so as to separate the solid particles from the flue. Since the cross section of the expanded cornering channel is larger than, preferably at least double, the cross section of the first flue channel, the flow rate of the flue will be dramatically reduced when entering to the expanded cornering channel. Therefore, the solid particles in the flue at the slow flow rate will be substantially precipitated into the collecting chamber 21 by gravity. The flue is then guided to exit the flue outlet 19 of the cornering channel, wherein the flue will strike to the rear-inner row tube set 32 and the rear-outer row tube set 33, such that solid particles will hit twice thereat and will drop at the collecting chamber 21. Preferably, the flue is guided to rapidly turn 180° from the flue inlet 6 of the cornering channel to the flue outlet 19 thereof. The flue will then be guided to flow along the second flue channel 16 at a relatively slow speed to the flue exit 15, wherein the flue direction at the second flue channel 16 is preferably vertically upward, such that the flue at the slow speed will prevent the solid particles being carried by the flow of flue again, so as to ensure all or almost all solid particles being separated from the flue. After the solid particles are collected in the collecting chamber 21, the solid particles are recycled and transferred back to the boiler furnace 1 via the dipleg 24 and the feedback valve 25. The solid particles in the circulating loop will be completely combusted and heat transferred. The flue without the solid particles will be exhausted at the vertical tunnel 17.
According to the first embodiment, when the flow rate of the flue is below a predetermined threshold, such as ≦5 m/s, of a slow circulating rate, wear protection should be partially applied at the first flue channel.
According to the second embodiment, the flow rate at the high dense area and at the low dense area of the boiler are that: higher than the circulating fluidizes bed boiler and below the low circulating rate, wherein the average rate at the first and second flue channel is between 3 m/s and 4 m/s, and the flow rate at the cornering channel is equal or less than 1.5 m/s. According the need of the boiler, the flow rate can be selectively regulated, wherein the water-cooled wall of the gas-solid separator can be fully exposed with partially wear-resistant treatment or can be fully exposed without any wear-resistant treatment. The second embodiment is the best mode of the boiler ≦35 T.
The operation process of the third embodiment is that: the flue blown out of the flue outlet 10 is guided by the film divider 9 to flow at the first flue channel 8, preferably the flue is rapidly turned 180° to the first flue channel 8, toward the collecting chamber 21, such that the solid particles are separated from the flue by means of inertial gravity and are precipitated at the collecting chamber 21. The flue is then rapidly turned its direction, preferably at 180°, at the flue inlet 41 to separate the solid particles from the flue and to precipitate the solid particles at the collecting chamber 21. The flue will multiply strike to the front row tube set 36 and the rear row tube set 37, such that solid particles will drop at the collecting chamber 21 so as to separate the solid particles from the flue. After the solid particles are collected in the collecting chamber 21, the solid particles are recycled and transferred back to the boiler furnace 1 via the dipleg 24 and the feedback valve 25. The solid particles in the recycling loop will be completely combusted and heat transferred. The flue without the solid particles will be exhausted at the vertical tunnel 17.
The gas-solid separator of the third embodiment can work with the low temperature cyclone type of separator together, wherein the low temperature cyclone type of separator is installed within the vertical tunnel 17 during operation.
According to the fourth embodiment, the height of the connecting tube 28 can be increased to reach the depth of the cornering channel, wherein there is not tube set being configured at either the flue inlet or flue outer. The tube set bottom transverse tube collecting box 38 is replaced by the film bottom transverse tube collecting box 43.
The operation process of the fourth embodiment is the same as that of the third embodiment.
The operation process of the fifth embodiment is the same as that of the first embodiment.
The operation process of the fifth embodiment is similar to that of the first and fifth embodiments, except the flue passing through the flue outlet of the cornering channel to strike against the rear-inner row tube set 32 and the rear-outer row tube set 33, so as to rise to the flue outlet 15 of the second flue.
According to the eighth embodiment, all collected data are theoretical and empirical data but not the restrictive data. For implementation, the configuration of the gas-solid separator can be specifically designed and modified to enhance the flexibility of the actual use of the gas-solid separator.
The operation process of the eighth embodiment is the same as that of the first and fifth embodiments.
The gas-solid separator in the ninth embodiment can be configured as the gas-solid separator in the eighth embodiment, or as the gas-solid separator with certain components or certain structures in the first to seventh embodiments.
The wear resistant application in the ninth embodiment is the same as that in the eighth embodiment.
The difference between the operation process of the ninth embodiment and the operation process of the eighth embodiment is that the flue passes through the flue outlets 10, 42 of the boiler furnace 1 concurrently to the first flue channel 8, wherein the flue passes through the gas-solid separator at the front side of the front wall 26 of the boiler furnace 1, enters into the longitudinal guiding channel 27 at the upper portion of the boiler through the second flue channel 16, and rearwardly flows to the vertical tunnel 17.
According to the tenth embodiment, the entire path of the first flue channel has the wear resistant treatment. The wear resistant treatment can be partially applied to the second flue channel depending the actual operation of the gas-solid separator.
The operation process of the tenth embodiment is the same as that of the ninth embodiment.
According to the first to tenth embodiments, the rear wall of the gas-solid separator is integrally formed with the front wall of the vertical tunnel. The water circulating system between the rear wall of the boiler furnace and the front wall of the vertical tunnel is a conventional water circulating system. Two sidewalls of the gas-solid separator are integrally formed with two symmetrical water-cooled walls. The upper portions of the symmetrical water-cooled walls are operatively linked to the bottom longitudinal tube collecting box while the bottom portions of the symmetrical water-cooled walls are operatively linked to the upper longitudinal tube collecting box. The down flowing duct of the boiler is operatively linked to the bottom longitudinal tube collecting box, wherein the fuel guiding duct of the boiler is operatively linked to the upper longitudinal tube collecting box.
The water circulation of the gas-solid separator starts from the two water-cooled sidewalls which are between the down flowing duct of the boiler and the bottom transverse tube collecting box upwardly to the upper transverse tube collecting box, and then enters into the boiler through the fuel guiding duct. The down flowing duct of the boiler is operatively linked to the collecting chamber transverse tube collecting box to upwardly guide the hot water to the film bottom transverse heater through the collecting chamber wall tube and the vertical tube set. The hot water is then guided to flow upwardly to the film tube set and subsequently to the film upper transverse tube collecting box. The hot water will be entered into the boiler through the fuel guiding duct.
According to the first to tenth embodiment, the gas-solid separator of the present invention should be a high range temperature gas-solid separator for the boiler ≧35 T, wherein the temperature at the flue outlet of the boiler furnace should be increased and the performance of solid precipitation should be enhanced to improve the heat convection and complete combustion. The gas-solid separator of the present invention should be a low range temperature or mid range temperature gas-solid separator for the boiler ≦35 T in order to reduce the height of the boiler.
According to the tenth embodiment, the structural configurations and components can be further modified to optimize the performance of the gas-solid separator so as to continuously improve and expand the use of the gas-solid separator.
One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201010572936.3 | Dec 2010 | CN | national |
| 201110036996.8 | Feb 2011 | CN | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CN2011/083017 | 11/28/2011 | WO | 00 | 12/23/2011 |
