JPS582527A - Flow controller of pulverized coal - Google Patents

Abstract

PURPOSE:To know a quantity of pulverized coal accurately and to carry out precise flow control, by obtaining the flow of the pulverized coal through values of a solid and a gaseous phase fluids and a solid-gas ratio. CONSTITUTION:Inactive gas is sent within a main duct 1 in an arrow direction through pressure by a blower 3. A dumping device of pulverized coal 9 is provided next to a valve 8. A flow signal Q of the inactive gas obtained by an evolution arithmetic unit 6 is multiplied by a constant K by a multiplier 16 depending on necessity and converted into a signal F. A pulverized coal weight signal W obtained from a belt scale 13 and the signal F are applied to a divider 17 and a solid-gas ratio W/F=Z is computed. A signal Qi showing a flow of the pulverized coal 9 is obtained by obtaining a signal DELTAPG through correction by the ratio Z of a measured differential pressure signal DELTAPtm of a flow meter 25a constituted with a venturi tube. The flow Wi of the pulverized coal is given by Wi=W.Qi/Q. With this, the flow of the pulverized coal can be found accurately and its flow control can be done precisely.

Description

[Detailed Description of the Invention] Example 1 regarding a pulverized coal flow rate control device used when pulverized coal is used instead of liquid fuel.
f, % combustion, l in blast furnace tuyeres or various industrial combustion devices;
! Conventionally, fuel oil or kerosene has been used for fuel oil or kerosene due to the inconvenience of the supply route and the reliability of flow rate measurement and control. Considering the effective prison term, it seems likely that pulverized coal will be used as fuel.

When using mold #vertical as fuel, it can be roughly divided into the following 2 types:
There are two problems.

One of these is how the pulverized coal is transferred to the combustion equipment through the pipe.When the molten coal is in contact with the air, friction between the particles causes static electricity, and spark discharge occurs. It is dangerous to cause an explosion, so in general, inert gas is used as a rear gas, flowed through the inert gas pipe IIC, and dropped into the flow of the inert gas to the AM device. It is thought that there will be 7 servings of charcoal and t$.・The second method is 0%, which is a method to measure the flow rate of pulverized coal.
After injecting pulverized coal into the inert fXJIc and making it into a solid air state, divide the tip of the tube into multiple tubes, and connect multiple combustion devices to the same 11 [KII [When feeding 1B coal, each The amount of pulverized coal in the branch pipe does not correspond to the amount of pulverized coal thrown in at 1=1.
Therefore, a device is required to measure the flow rate of pulverized coal in each branch pipe.

The 10th team book uses previously proposed techniques to solve the problem, but when it comes to the 11X2 problem, no technology has been proposed that would solve it.

As measuring means for determining the flow rate of a solid-gas two-phase fluid consisting of an inert gas and pulverized coal, the radioactive tracer method, the microwave method, the capacitive layer correlation method, and the like have been proposed. However, these flow measuring means have the disadvantage of being expensive and overly complex. It is not suitable for 41 to 40 blast furnaces in use.

The purpose of this project is to provide a flow rate control device that uses a simple and inexpensive flow rate needle to maintain a constant flow rate of a solid-gas two-phase fluid and to control the flow rate sound. Now, use pliers and a V-tube to determine the flow rate tm of the solid-gas two-phase fluid, and keep the solid-gas ratio of the solid-gas two-phase fluid constant, and from the solid-gas ratio and the flow rate of the solid-gas two-phase fluid, it is determined that it is solid. It is designed to find the flow rate of pulverized coal.

Therefore, according to the present invention, it is difficult to determine the amount of Cl in the same atmosphere using pliers and a tube, which have been widely used in the past. Therefore, it is difficult to obtain a low-cost KII gas two-phase fluid t) R amount measuring device. However, the flow rate measurement value tm
The solid flow rate is calculated by correcting it by the air ratio, and the flow rate of 11 times of mold is accurately determined. Therefore, there is an advantage that highly accurate flow rate control can be performed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained in detail below using a drawing of a tube.

In FIG. 1, 1 indicates the main pipe. An inert gas source 2 that generates an inert gas such as nitrogen is connected to the end K of the main pipe 1, and a blower 3 pumps the inert gas through the main pipe 1 in the direction of the arrow 40. The flow rate of the inert gas blown by the blowing method 3 is measured by a flow meter 5. Flowmeter S
In this example, pliers and a tube are used to measure the flow rate. The pressure difference is subjected to square root calculation 1111 to be converted into a flow rate signal Q and made constant. The ζO flow rate signal Q is seen at the measurement signal input terminal PV K4 of the controller 7. The output of the controller 7 controls the valve 8 to control the flow rate of the inert gas.

Next KF after valve 8! @Powder lR90 dropping means 11 is omitted. The pulverized coal 90 dropping means 11 can be configured, for example, by a hopper 12 and a motor 4 that drives a belt scale 13J and a belt school 13. 90 pulverized coal sent per unit time by belt scale 13
Keep the weight constant and input the weight W into the controller ISK.

The speed of the P4-tater 14 is controlled by the output of the adjustment needle 16 to control the amount tm of pulverized coal 9 introduced into the main pipe IK.

The inert gas flow rate signal Q obtained by the square root calculator 1 is multiplied by a constant K1 in a multiplier 16 and subjected to No. 1 FK conversion, if necessary. The signal r and the pulverized coal weight signal W obtained from the belt scale 13 are supplied to the divider Jl@17.
At! ! -2. Calculation corner.

[T] This 2 is the ratio of pulverized coal 9 to inert gas, and this is usually called the solid-gas ratio, so l! and a flow meter 5, a square root calculation aS, and a belt scale 13.

Square S unit 16. and a divider 17 constitute means 18-fi for measuring the solid-gas ratio zvt.

How to maintain a solid-air ratio of 2! For example, R18 can also be used as shown in Figure 2.
indicates the pent-hole tube, the differential pressure 4P1 generated at the constriction part of the tube 21 and the differential pressure I'm between the broken part on the outlet side and the open part. and t differential pressure gauge 2 pieces 2.do.2
3, and by calculating the stiffness ratio z of the field 2s#1 body by ``using these differences E, Pm and lPm, and calculating ζ'', we obtain 1゛. , In this calculation, it is assumed that the solid-gas ratio 2 may be determined by any method of ζ1.

The main pipe 1 is located downstream of the pulverized coal/9'/' input position.
multiple "branch pipes 2-"141'#'2, 4 b,
24 a-...24-m - is divided into 1IIt. For example, if the moldy powder coal is 2"OO mesh, then the main pipe 1 or the branch pipe B will be heated for 1 to 2.4 mK, and the % solid-air ratio 2 will not change. So 1.ゐ゛.

Each of the branch pipes 241 to 241 has a flow meter 25 a e 25 h a 'l configured with pliers and a pipe.
3 @ -...-2% Valve ff1 that controls m and flow rate
8m-18m251EIl is cut 0m''c, #i' axillary pipe 2] & is draining water. Use pliers, pipe is constructed, good, flowmeter-25a401
The constant differential pressure signal jPi is supplied to a divider 27, where a correction calculation is performed based on the solid-air ratio ZK. By this O correction calculation, the differential pressure ΔPa generated by KMlj4 due to the flow of pulverized coal 9 is obtained. This differential pressure Δ
A signal Qi representing the flow rate of the pulverized coal 9 is obtained by calculating the square root of Pa using the square root calculator 28. ζJ-
The quantity Qi is multiplied by the mold powder vertical 90 weight signal W by multiplication @2Gk, and further, the divider 31 divides W-Qi by the inert gas flow rate signal Q to obtain the mold coal powder flow rate Wi■-・Obtain Qi. Therefore, these performances JEl! -Bulk 27.28.29.31
A calculation means 30 for determining the amount of coal flowing through the mold is also constructed. The flow rate i of this pulverized coal 9 is given to the one-node needle 32.

In this example, the setting signal input terminal 'f-8PK of the controller °32 corresponds to the air-fuel ratio from the air-fuel ratio measuring means 33 and gives a nine-fault number Wd, and the flow rate W1 of the pulverized coal 9 is equal to the air-fuel ratio signal W41 and the one valve 2.
The ambient two-phase fluid whose current amount is controlled by the combustion device 34aK is supplied to the combustion device 34aK, and in this example, the “combustion device 3
4 shows the case of using Shizo Birch.
Hot air is supplied through the fsst. The line is divided into good numbers corresponding to the number of air blow Δita 3s. Each branch pipe 351-351
A flow meter 36m and a valve 37m are inserted in the .

In the figure, only the branch pipe 35 is shown. The flowmeter 36m can also be adjusted by using pliers, for example. rIL
The measured value of the quantity meter 36aO is subjected to a square root calculation by a square root calculation unit 38, and converted into a flow rate signal QAiK. This flow rate signal QAi is input to the controller 39, and the output of the controller 39 causes the valve 371 to
``1 control, and control the air supply amount dust = ``constant value tube'' to be maintained.

Shang Kaiping - '380' output is addition @41 and arithmetic unit 42
Also supplied to other branch pipes 351 in this adder 41
Add all the OvL quantity signals from the flow rate needles installed at ~3511K to find the air quantity ΣQi. This is applied to the adjustment needle 320 set value input terminal 89 described above.

On the other hand, in this Yamei Km, flowmeters L5m to 251 are installed in front of the flow rate needles 28a to 2sIk that measure the flow rate pipes of solid-gas two-phase fluid.
A means for cleaning 44 pipes is provided. This cleaning element llI44 is made by, for example, a steam emitting nozzle. In other words, the solid-gas two-phase fluid is squeezed with pliers like a tube O.
In the holding part, pulverized coal 9 adheres to the squeezed part of 7,
It has the disadvantage of generating measurement error tubes. Therefore, in this case, the flow rate needle is 25m0fIN. 〔Silver flowmeter〕For example!
Branch pipe 2 4 a 0IIID O from SaO position
Is IFa degree or higher: Flow @ steam emitting nozzle 4
Install 4&・4! On the further upstream side of the steam discharge nozzle 441, close the valve nsa according to the command from the tie t40, and write to stop the II gas fluid O@t'L.In this state, the tights 400al command is written. yo〉claw #
Inject steam from 44a to the weight needle ts& and clean the flowmeter zsat. ζO cleaning timer 40 for each branch pipe 24h~24mKMIm.Flow rate needle 2sa~
Regarding the 2s song, IMI will perform at certain times.

In this way, the flowmeter is 25m-2! ! If the pulverized coal is washed with steam, the pulverized coal is
Even if it adheres to the tD part of the pipe, it can be removed at regular intervals. Therefore, the measurement tank can always be maintained in a normal state.

For cleaning with steam, use the flow meter 25 &~! l! IsmK
For example, the flow control valve 261 can also be provided in the same manner.

Furthermore, this! At l@, we also propose a structure that ensures differential pressure adjustment between 25 m and 25 m of flowmeters constructed with pliers and a pipe. In other words, the pliers and optical flow positioning needle are configured to measure the differential pressure generated between the input side of the tube and the tube differential pressure gauge 46 as shown in g311. For this reason, conduits 47 and 411 are led out from the input side of the constriction part of the pipe 24at) and the conduit part. These conduits 4tea8 are connected to the peripheral pipe 210 and the differential pressure gauge 4 (i).
Near 0 (k valve 49a.

49% and 51a. 51b and connect valve ss to differential pressure gauge 460 constant input q. Normally, valve s2 is closed.
- (but, differential pressure ゛total 4@t) 4゛mouth point 1** sui 1) total a
Close valve 49 bkUs 1 b e-C” valve 52tll
In this state, correct the 4mm point tube.

In such a differential pressure measurement system, if pulverized coal contained in the solid-gas two-phase fluid flowing through the pipes flows into the conduits 47 and 48, there is a risk that the conduits 47 and 48 will be blocked by the pulverized coal. be. Therefore, by constantly supplying inert gas to the conduits 47 and 48 (during measurement) through the inert gas source 2 or the pressure reducing valve 53.54 t, and releasing it into the passage of the inert Istm constant two-phase fluid. > A layer is formed to prevent pulverized coal from entering the conduits 47 and 48. The flow rate of these two inert gases is 0.0% of the flow rate of the measurement fluid. If the temperature is selected to be s-1 degrees, it is possible to prevent the inert gas from exerting a constant influence.

As described above, according to the present invention, each branch pipe 246-2
Based on the flow rate value of the solid-gas two-phase fluid flowing through 41 and the solid-gas ratio ZK), calculate the flow rate of pulverized coal 9, and from 9, calculate each combustion device 34a to 34+.
It is possible to accurately know the amount of pulverized coal to be given and reduced. However, the flow rate needles are all standard specification flow needle tubes, and each calculation element is also made of standard specification products, so it can be made cheaply as a metal body even though it may be hot.

Furthermore, in this issue, with respect to the flow meters 2sa to flsmK that determine the flow rate of the solid-gas two-phase fluid, a cleaning means 4 using steam is used.
49, and the flowmeters 25m-15mtfi1. Since the structure is configured to have #, it is possible to prevent the occurrence of a constant difference due to the adhesion of pulverized coal.

Furthermore, in this development, the pliers and the conduit 4 of the differential pressure needle in the tube are
Since a small amount of inert gas J is always flowed to 7 and 48, there is no leakage to the differential pressure gauge 46 and pulverized coal does not enter the conduits 47 and 48, so conduits 47 and 411 are placed under the pulverized coal. Without a doubt.

It can operate stably over a long period of time.

In the above description, each calculation element 17, 18, 27. ,28°2G
, 31.318.41.42.43 as an element composed separately in 4, but as shown in Figure 4, each performance JE
II*0. Calculations and control of the valve 26 can be performed by the calculator s5. In this example, the blast furnace or the like is configured to control the amount of pulverized coal 9 thrown in (by the temperature signal -56), and the tube shows the amount W of pulverized coal thrown in and the flow rate of inert I.

In addition, the solid-air ratio z is calculated, and the solid-air ratio 2 and each dividing scissor tube 24a ~
Based on the flow rate signal of 2411], determine the flow rate of pulverized coal in each branch pipe 24 & -24-, and set the air flow rate needle 36 to 38 m of each tuyere.
Depending on the farewell date] select the optimum amount of pulverized coal for each farewell date from valves 26a to 2.
Controlled by six difficulties.

Additionally, the operation of the cleaning means 44 at regular intervals can also be controlled by the calculator 55.
e minute wrinkle w 24 m, 24 k =”24 mta
When the flow rate of the solid-gas two-phase fluid is controlled separately by the pipe valves 26a to 26,
It is also possible to control only the amount of C air. In this case, for example, the amount of pulverized coal 9 to be dropped may be controlled from a constant value of the solid-gas two-phase fluid using the flowmeters 28a to 261. A case is shown in which the flow rate of pulverized coal 9 is controlled by changing the solid-gas ratio z.

[Brief explanation of the drawing]

Figure 1 is an example of the present invention.
3 is a layout diagram showing a concrete embodiment of the main part of this invention, $14#tJ7! Fji sth
g is a diagram showing the embodiments of this invention. , l...main, 2-...
Inert f x @[%3・-Blower. 11... Fine powder placement JR%i @ -, - Solid-gas ratio measuring means. 25 am 26 rate = pente, ha amount meter by pipe. 26 - 26 mm - control valve, SO - - calculation means 1341 - 34 O - combustion device, which calculates the pulverized coal flow rate tjlltl from the ratio and the solid-gas two-phase fluid flow rate. Patent applicant: Hokushin Electric Co., Ltd. (1 person)
Taku No

Claims (1)

[Claims] means for sending inert gas and pulverized coal into the pipe; means for dropping pulverized coal into the inert gas flowing through the pipe; and measuring means for determining the % solid-air ratio 1; and the inert gas and pulverized coal. The flow rate of two fluids at once consisting of pliers, a pipe and one O bench, and a solid gas measured with a pipe and a 2mm body 01! a calculation means for calculating the flow rate of pulverized coal from the IE column fixed value and the solid-air ratio;
According to this performance, a pulverized coal flow rate control device comprising a means for controlling a single flow rate pipe of pulverized coal;