JPS63169411A - Fluidized bed boiler - Google Patents

Abstract

PURPOSE:To enable effective utilization of waste lime stone and to reduce an amount of lime stone, by a method wherein a crusher is connected to the discharge port of a waste desulfurizing agent, a molding extruder, to which the lime stone piping of the crusher and a different fuel feed pipe are connected, is connected to the combustion chamber of a boiler body through a reduction pipe. CONSTITUTION:Waste lime stone 15, which is modified by desulfurization and gathered at an upper layer higher than an inflow port 24a, of lime stone 15 in a desulfurizing chamber 10, flows over the inflow port 24a, and discharged through an extraction cylinder 24 to a crusher 25. By crushing the waste lime stone by means of the crusher 25, plaster being an outer hull is crushed to expose quick lime present at the interior, and is fed to a molding extruder 27 through a fuel feed pipe 28. In this case, since waste plastic, lime stone, fuel such as coal are fed through a fuel feed pipe 29 into the moulding extruder 27, the quick lime and the fuel are kneaded, and the kneaded substance is extruded in a pelletform through an extrusion port. The kneaded substance of the quick lime and the fuel is returned through a reduction pipe 30 to a combustion chamber 9, the fuel is burnt, and the quick lime is used for desulfurization of combustion gas.

Description

[Detailed description of the invention] [Industrial application field] The present invention supplies coal into a fluidized combustion chamber in which sand flows, burns it, heats the water in the heat transfer tube, generates steam, and burns the coal. This relates to a fluidized bed boiler that desulfurizes the remaining gas using a desulfurizing agent and discharges it to the outside.

[Conventional technology]

In recent years, fluidized bed boilers have been developed as boilers with high combustion efficiency and low waste gas pollution. This type of fluidized bed boiler has storage chambers separated from the bottom in order from the bottom of the boiler body.
It is equipped with three chambers: a combustion chamber and a desulfurization window, and the sand that is sent from the storage chamber to the combustion chamber and always stored in the combustion chamber in a predetermined amount is fluidized by blowing air, and the coal supplied to the combustion chamber is converted into sand. Steam is generated by heating the water passing through the heat transfer tubes of the combustion chamber with the combustion gas. The combustion gas is then desulfurized using a desulfurizing agent such as limestone in the desulfurization chamber and exhausted, and unburned carbon is captured and burned in the desulfurization chamber.

[Problem that the invention seeks to solve]

However, in conventional fluidized bed boilers, the waste desulfurization agent used for desulfurization is discharged from the outlet and disposed of, which requires a large supply of new limestone, which is not always satisfactory in terms of material consumption. Ta.

[Means for solving problems]

In order to solve these problems, in the present invention, a crusher is connected to the waste desulfurization agent discharge port, and a molding extruder and boiler main body are connected to the limestone discharge pipe of the crusher and another fuel supply pipe. The fuel chamber was connected with a reduction pipe. Also,
In another invention, an H,0 supply pipe was connected to the pulverizer, and a reduction pipe was connected between the pulverizer and the desulfurization chamber of the boiler body.

[For production]

After being used to desulfurize the combustion gas, the Kuwase desulfurizing agent is discharged from the exhaust port and is crushed in a crusher. When the plaster that forms the outer shell cracks and the lime inside is exposed, this is fed to the molding extruder. When mixed with separately supplied fuel such as industrial waste and unburned ash 1 lime, kneaded and extruded, it is extruded into a pellet shape, which is then returned to the combustion chamber and burned as fuel. At the same time, it also has a desulfurizing effect. Also, to the crusher
When the waste desulfurization agent is crushed while supplying 2O, the hydration power y
Since it is discharged as sium, the residue is placed in the desulfurization chamber 1a and used for desulfurization.

〔Example〕

FIG. 1 is a longitudinal sectional view showing an embodiment of a fluidized bed boiler according to the present invention. In the figure, the main body 1 of the fluidized bed boiler is surrounded on four sides by water-cooled walls 2 in which a plurality of water-cooled pipes (not shown) are buried, and is shaped like a box of a rectangular ship.
Partition plates 4, 5.6 containing 3 water-cooled pipes in three stages form an air chamber 7° and a storage chamber 8. Combustion chamber9. A desulfurization chamber 10 is separated. Air pipes 11 and 12 connected to an air blower (not shown) are inserted into the air chamber 7 and the storage chamber 8, respectively, and air is blown into the combustion chamber 9.
A pneumatic coal supply pipe 13 connected to a coal supply hopper (not shown) via a dryer and a crusher is connected to supply coal. Furthermore, a pneumatic limestone transport pipe 14 connected to a limestone supply hopper (not shown) via a crusher is inserted into the desulfurization chamber 10, so that a predetermined amount of limestone 15 is always kept in the desulfurization chamber 1a. is supplied so that it can be stored. Reference numeral 16 denotes a heat transfer vibrator installed in a curved manner so as to reciprocate in a staggered manner within the combustion chamber 9, and an air supply pipe 1T connected to one end of the vibrator 16 is connected to a circulation pump, and a The connected supply pipe 18 is connected to steam-using equipment. In addition, in this embodiment, a bypass is provided to connect the air supply pipe 1T and the supply pipe 18 in the middle, and serves as a heat transfer tube of a separately provided waste heat utilization boiler. A plurality of distributors 19 are provided on each of the partition plates 4, 5, and 6, and are used to uniformly distribute the blown air and sequentially blow it up into the upper chambers.

Sand 20 as a fluid medium having a diameter of about 1.6W is stored in the storage chamber 8, and the same sand 20 is also stored in the combustion chamber 9 in the lower layer of the supplied coal. It is stored. Reference numerals 21 and 22 denote an upper comer and a downcomer for the sand 20, which are provided in communication with the storage chamber 8 and the combustion chamber 9, and the sand 20 is transferred to both chambers 8 and 9 by manual or level detection using a senna, etc. The sand 20 is moved back and forth between the combustion chambers 9 and 20 to keep the amount of sand 20 in the combustion chamber 9 constant at all times. - An exhaust port 23 for discharging the combustion gas is provided at the upper end of the desulfurization chamber 10, and the exhaust gas is passed through the exhaust heat utilization boiler to the chimney via a duct.

Furthermore, a waste limestone extraction tube 24a whose inlet 24a is inserted into the upper layer of the limestone 15 is inserted into the through hole provided in the water-cooled wall 2 of the desulfurization chamber 10, and the 7th rank part is inserted into the outer surface of the water-cooled wall 2. Fixed to i? The limestone 15 which has changed in quality due to desulfurization and has gathered in the upper layer overflows into the extraction tube 24 and is discharged. Therefore, the inlet 24b is always open to the surface of the limestone 150. The inside of the waste limestone discharged from the extraction tube 24 is quicklime (Cab), and the outer shell is made of stone IF (Cab).
e) It is wrapped in 25 is the bracket 2 on the book 1 side.
A crusher, such as a hammer crusher, supported through a shaft 6, to which the discharge port 24b of the extraction cylinder 24 is connected with a 7 flange, is used to crush waste limestone discharged into the machine from the discharge port 24b. It is constructed so that 1 ton of stone (CBSO*) is broken open to expose the quicklime (Cab) inside. 2T is a limestone discharge pipe 28 between the crusher 25
A twin-screw molding extruder connected by
A fuel supply pipe 29 is connected to supply fuel such as industrial waste such as waste plastic, limestone, and unburned ash9 coal.
) and fuel are kneaded into pellets and extruded. The extrusion port of the molding extruder 2T and the combustion chamber 9 are connected by a reduction pipe 30, and the mixture of quicklime (Cab) and fuel discharged from the molding extruder 2T is returned to the combustion chamber 9. Along with combustion, the combustion gas is desulfurized.

The operation of the fluidized bed boiler configured as above will be explained. After supplying coal to the upper layer of sand 21 stored in the combustion chamber 9 and sending air to the air chamber T and the storage chamber 8, when the coal preheated with a burner etc. is ignited, the coal is heated by the supply of combustion air. is combusted, and this combustion is caused by the distributor 19
The sand 21 and coal are fluidized by the air blown up from the combustion chamber, promoting efficient combustion. This combustion heats the water in the heat transfer tube 16 to generate steam, which is supplied to steam-using equipment. -10,000, the combustion gas enters the desulfurization chamber 1G via the distributor 19t-, the sulfur content is removed, it becomes a harmless gas, and is discharged from the exhaust port 23-, while unburned carbon is captured and burned in the desulfurization N1G. . The combustion gas discharged from the exhaust port 23 heats the steam headed from the supply pipe 18 to the steam usage equipment when passing through a separately provided boiler, and then is discharged from the chimney.

Furthermore, among the limestone 15 in the desulfurization chamber 10, the waste limestone 15 that has changed in quality due to desulfurization and has gathered in an upper layer so as to be higher than the inlet 24a flows over the inlet 70- from the inlet 24a and reaches the extraction tube 24'f. , and then discharged to the crusher 25. This waste limestone is crushed by the crusher 25, thereby cracking the outer stone wall (CBSO4) and exposing the internal quicklime (Cab), which is then supplied to the molding extruder 2T through the limestone discharge pipe 28. At this time, the quicklime (CaO) and fuel are kneaded and extruded from the extrusion port in the form of a pellet. The mixture of extruded quicklime (Cab) and fuel is removed from the reduction pipe 3.
0 and is returned to the combustion chamber 9, where the fuel is combusted and the quicklime is used to desulfurize the combustion gas.

In addition, molding extrusion is performed from the fuel supply pipe 29! ! ! As the new fuel supplied to No. 27, unburned ash in the waste gas can be used. That is, a dust collector is provided between the discharge pipe 23 and a boiler (not shown) to extract ash with a large amount of unburned content, which is supplied to the bottom extruder 27 and returned to the combustion chamber together with limestone, where it is combined with new lime. If the fuel is allowed to combust, the unburned matter can be effectively combusted.

The second factor is a vertical cross-sectional view showing an embodiment of a fluidized bed boiler according to another invention, and this will be explained based on the same figure. Since the configurations of the boiler main body, extraction tube, and crusher are the same as those of the fluidized bed boiler shown in Figure Wc1, the same reference numerals will be given to them, and the explanation of their configuration and operation will be omitted. An &O supply pipe 31 supplies H2O such as steam or hot water to the crusher 25.
The quicklime discharge port of the crusher 25 and the desulfurization chamber 10 side of the boiler body are connected by a reduction pipe 32.

With this configuration, the waste limestone supplied from the inlet 24 to the crusher 25 is
Steam supplied from the H2O supply pipe 31.

It is crushed while adding H2O such as hot water, and the outer stone (C, SO4) cracks and the quicklime (Cab) inside is exposed. As a result, C, O, and H2O react to form calcium hydroxide (CB(OH)m), which is discharged. The discharged calcium hydroxide (Ca(OH)) is reduced to the desulfurization chamber 10 through the reduction pipe 32, and is used as a desulfurization agent for desulfurization of the combustion gas.

Note 1. In each of the above embodiments, the crusher 25 is extracted and the cylinder 2 is removed.
An example was shown in which it was directly connected to the discharge port 24b of No. 4 and attached directly to the boiler body, but it was crushed! ! 25 may be provided separately from the boiler main body, and after the waste limestone discharged from the extraction tube 24 is stored in a tank or the like, the required amount is supplied to the crusher 25 for crushing. In addition, as in the example, boiler '7g: crusher 25 directly connected to the body and extrusion molding! !
A tank or the like may be provided between the pulverizer 25 and the quicklime 27, and the quicklime obtained by pulverizing it in the pulverizer 25 may be supplied to this tank using a chute, a conveyor, etc., stored therein, and then sent in the required amount to the molding extruder 2T.

Further, in each of the above embodiments, limestone is used as an example of the desulfurizing agent, but other desulfurizing agents such as dolomite may also be used.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in a fluidized bed boiler, a pulverizer is connected to the waste desulfurization agent outlet, and the limestone discharge pipe of the pulverizer is connected to another fuel pipe. By connecting the molding extruder and the combustion chamber of the boiler body with a reduction pipe, waste limestone with new fuel added is returned to the combustion pipe to perform combustion and desulfurization. can be effectively utilized and the amount of limestone supplied can be reduced. According to another invention, a crusher is connected to the outlet of the waste desulfurization agent, and H2
Connect the O supply pipe and connect this pulverizer to the desulfurization chamber of the boiler main body with a reduction pipe, and use a quick reaction to turn waste limestone into calcium hydroxide and return it to the desulfurization chamber to perform desulfurization. By draining the limestone, waste limestone can be used effectively and the supply of fresh limestone can be reduced, leading to resource savings.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the fluidized bed boiler according to the invention set forth in claim 1, and FIG. 2 is a longitudinal cross-sectional view of the fluidized bed boiler according to the invention set forth in claim 2. It is. 1...Main body, 2...Water cooling wall, 9...-combustion chamber, 10...Φ desulfurization chamber, 1411...Φ limestone transport pipe,
15...limestone, 23...outlet, 24...
・Extraction cylinder, 24a...Inflow port, 24b...
Outlet, 25.Fist/war crusher, 27..-forming extruder, 28..limestone discharge pipe, 29..e. fuel supply pipe, 3Qees-reduction pipe, 31..H2O supply tube, 3
2. Fist/reduction tube.

Claims (2)

[Claims] (1) A pulverizer that crushes the waste desulfurizing agent to be discharged and exposes lime from the outer plaster is connected to the exhaust port of the waste desulfurizing agent, and a lime discharge pipe of this pulverizer and a separate fuel supply are connected. A fluidized bed boiler characterized in that a molding extruder is provided in which pipes are connected and lime and fuel from both pipes are kneaded and extruded, and the extrusion outlet and the combustion chamber in the boiler body are connected by a reduction pipe. . (2) A pulverizer that crushes the waste desulfurizing agent to be discharged to expose lime from the outer plaster is connected to the waste desulfurizing agent outlet, and a H_2O supply pipe is connected to this pulverizer, and A fluidized bed boiler characterized in that this crusher and a desulfurization chamber of the boiler body are connected through a reduction pipe.