JPS586827A - Constant flow control unit for high pressure powder/gas pipe transport system - Google Patents

Abstract

PURPOSE:To ensure constant conveyance by detecting the pressure difference between at the sending portion of powders and at the inlet portion to a furnace and by controlling a gas flow, solid/gas ratio, and the pressure difference between both portions at constant values. CONSTITUTION:The compressed air introduced from a compressed air source 10 is guided into the flow portion 3 of a fluidized bed pressurized tank 1 in which powders such as pulverized coal are filled, then the powders are fluidized, are conveyed through a transport pipe 6, and are fed by pressure to a receiving unit 8 such as an inlet port of a blast furnace or a blast port of a converter. According to this constitution, pressures, solid/gas ratio, and flows at the flow portion, receiving portion, and other portions are detected and sent to the control unit 28 so that the flow is controlled by use of a bypass passage 14, etc. and the pulverized coal fed to the receiving unit can be controlled at a constant value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant flow rate control device for a high-pressure powder and granule gas pipe transport device that transports powder and granules using pressurized gas.
The pressurized flow rate*m is applied to a fluidized bed pressurized tank filled with powder and granules.
Pressurized gas is supplied from a pressurization line having a valve through a fluidized bed, and a constant flow of powder and granules is sent to a transport line connected to the pressurized tank and transported to a receiving device K. It is suitable for application to transportation equipment.

This transportation device is used to transport powder and granules, such as pulverized coal, to receiving devices such as blast furnace linings, converter inlets, ladle desulfurization lances, etc. under high pressure. In addition to transporting the powder at a constant flow rate, it is also preferable to transport necessary combustion-supporting gas for combustion equipment such as a blast furnace and inert gas to the ladle together with the powder.In this sense, the solid-gas ratio or total It is rare to transport granular materials at a constant flow rate while maintaining the pressurized gas flow rate at a constant value.

In addition, when the pressure on the powder supply side, that is, the pressurized tank, fluctuates, it is desirable to transport the powder at a constant flow rate while maintaining the difference between the pressure inside the pressurized tank and the pressure inside the receiving device at a constant value. ing.

The present invention aims to provide a new constant flow rate control device for a high-pressure powder gas pipe transport device that can reliably satisfy the above-mentioned *i.The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a system diagram showing a high-pressure powder gas pipe transport system, in which (1) is a fluidized bed pressurized tank into which powder such as pulverized coal is filled via an input valve (2). , (3) is a fluid, (
4) is an exhaust valve.

(6) is a transport pipe connected to the pressurized tank (1), the tip of which extends into the tank as a discharge nozzle (5) and faces the fluidized bed (3).

(8) is a receiving device having a required pressure (P, ),
The other end of the transport pipe (6) Kli! It is continued. Receiving device (
8) may be a combustion device such as a tuyere of a blast furnace, an inlet of a converter, or an O-tally kiln, as well as a ladle for desulfurization, a hopper, or the like.

α1 is pressurization of combustion-supporting gas such as air, inert gas, etc. (3)
K is supplied to the transport pipe (6) through the bypass line Q4 with the flow rate IItlj valve 03 interposed. Weight inspection me, aη is the fluidized bed pressure in the pressurized tank (
The pressure detector (2) for detecting Pl) is connected to the pressurized gas supply source -
A flow rate detector such as an Olyice or the like which detects the total gas supply flow rate of the spider, (2I) is a flow rate detector such as an Olyice or the like interposed in the bypass line a4). In this case, by increasing the flow rate of pressurized gas in bypass line I, as will be explained later with reference to FIG.

The amount of powder material cut out can be controlled.

(Foundation) detects the pressure difference between the fluidized bed pressure in the pressurized tank and the pressure at the outside of the tank in the transport pipe (6), and estimates the amount of powder and granules cut out by the discharge nozzle from the pressure loss. Vessel, (2)
is a pressure detector that detects the pressure of the receiving device (8).

(e) is a V constant input device such as a keyboard, which includes the desired tank weight change rate (''/dt), solid-air ratio -1 pressurized gas flow rate (QT), and bypass line pressurization. Input the gas flow rate (QB), etc.

(C) is a control device, and each of the detectors (Ie, aη
(1) The detection outputs of Qυc12 and (c) and the output of the set value manual device M (c) are supplied, and based on these, a predetermined control l output of the flow rate regulating valve αυ03 is obtained. The contents of this control device (to) are as described below. In the apparatus shown in Figure 1, the dimensions of each part are as follows: equivalent pipe length of the transport pipe (6) L e = 140 m, nominal diameter of the transport pipe Di = 25 A, pulverized coal particle size d P = 200, mesh residue Fi = 20%, Pressurized tank volume V = l m”
and the receiver pressure is P, =2, or;g7e
As a result of experiments using iar, characteristic curves E and F shown in FIG. 2 were obtained. In Fig. 2, the vertical axis is the tank weight change rate dw/dt (7b), and the horizontal axis is the bypass line gas flow 11QB (NW!/h) and the total supply gas flow rate QT (
N! 0 song lIE which is I//h) is cksr/dL=-
AQB+B+C(P% Pt) --(1) (However, A
, B and C are constants), and the curves a m, , El , Es and E represent the pressurized tank pressure (Pl) of 4.4.5.5 and 5, respectively. .5r4/♂G
The characteristic curve + menu name - fork curve F obtained when K is set is a characteristic curve expressed as dw/d t = m - r G - Q, (where r is the specific weight of the pressurized gas). There, song I
f Fs , Ft , Fs, F4 and F are respectively [%J
These are characteristic curves obtained when tm is set to 5.1O115, 20, and 25, respectively.

As is clear from this figure, (1),) When transporting powder with a constant pressurized gas amount, select the desired total processing flow rate Q1 from the horizontal axis and QT
Select the intersection point k between the straight line X and a selected curve E, for example, the curve mE1, where )
Select the differential pressure (Pl・−P,・). Therefore, in the figure, when the total pressurized gas flow rate is 5ONm//h, the differential pressure (P,! -P, )==4-2=2I/,d(,
If the tank weight carbonization rate is maintained at dw/dt=8004/
At h, constant flow rate transportation is possible with the total gas flow rate constant.

(Smell) When transporting powder while keeping the differential pressure (Pg Pt) constant, cinnabar (PtP*) is calculated using the formula (1) above.
Since is a constant, equation (1) is dw/di'', so Q-1B
'Next to Figure 2, *, is one straight IJG shown.
Therefore, the desired powder transport amount (d w /d t)
To obtain this, the bypass gas flow rate on the horizontal axis is variably adjusted to
By selecting dw/dt on the vertical axis at one intersection with 1G, constant flow rate transport is possible with the differential pressure (Pg Pt) constant.

(3) When transporting powder while keeping the solid-air ratio m constant, select the desired solid-air ratio, select the straight line F, ~F, corresponding to the solid-air ratio, and transport the desired powder Body transport lid (dw/dt
), or select the bypass gas flow ff1QB and the pressurized tank internal pressure (P, ) from the intersection with the curve ML~E4, which is equivalent to
) By selecting , it is possible to transport powder and granular material at a constant flow rate with a constant solid-air ratio. From the above results, the above characteristic surfaces @E, F, and G are stored in advance in the control device @, and this 1! l Control device (to) K Each of the above detections Solid-gas ratio - or total processing gas flow rate (Q)
and pressurization pressure (P, ) are automatically set to KI [ll
By setting and supplying the calculation at 1 ft increments,
An operation control output for operating the flow rate leg valve control υa3 can be obtained from the control device (to), and the total processed gas flow rate (
It is possible to carry out constant flow rate transportation of powder or granular material by keeping any of Qa), differential pressure (Pg Pt), and solid-gas ratio constant.

The mass flow rate of only the powder in the transport pipe (6) is determined by weight detection 1i! Instead of the output of Qe, it can be measured as described below. That is, the pressure loss ΔPT between two distant points on the transport pipe (6) is ΔP? =Δp, +K1mQ,, =-, Q4
+, mQ.

--Represented by (1). However, ΔP is the pressure loss due only to the pressurized gas (Q, r) when the particle size is zero, m is the solid-gas ratio, and K, , K are proportional constants. ,
i, - Also, the mass flow rate table of powder and granular material is W = mQT-
- (2), (1) (from the formula) W = (△PT 'tQ7)/ becomes *-- (3),
After all, the flow rate of the powder or granular material can be determined by calculating a constant value, KK, in advance, and detecting the loss pressure and the pressurized gas flow rate.

On the other hand, when the pressurized gas flow rate (QT) is determined by the Oriais differential pressure △PO, it is expressed as Q T ==Ks MU (where 1 is a proportionality constant), and therefore, by squaring both sides, QQ T
” Ks△PO, and by substituting this into equation (3), we get
W = 4 (△PT-, △Po) --(4) However, 4
-ni:/niini, :ni, becomes KS. In addition, in the case of pressure loss in the discharge nozzle, QT at (1), (2), and (3) 2 is (QT-QB)K! It's fine if you change it - 0 but △P
Since the value of , is negligibly small, equation (4) yields 4ΔPT for Wφ.

Therefore, the output of the differential pressure detector (2) or the differential pressure detector (to) that detects the differential pressure between two distant points of the other transport pipe (6).
The mass flow rate of only the powder can be measured based on the output of the flow rate detector (2).

As described above, according to the present invention, any one of the total processing gas flow rate, the differential pressure between the pressurized tank pressure and the receiving device pressure, and the solid-air ratio
It has the great feature of being able to transport powder and granules at a constant rate at a constant level of -2, and is suitable for processes with pressure, injection carbon, high solid-gas ratio fuel supply, blast furnace bed distribution, etc. A usable powder transport device can be provided.

In addition, by intermittently changing the bypass gas flow rate, it becomes possible to perform pulse combustion, plug transportation, etc. In addition, in the above-mentioned tsuba, powder and granular material from the pressurized tank (1) can be transported in batches. As described above, when the powder and granular material in the pressurized tank (1) falls below a predetermined level, the pressure inside the pressurized tank (to) is equalized with the pressure inside the pressurized tank (1).
In this state, the powder and granules in the pressurized tank (to) are transferred to the pressurized tank (1
), and at this time, the output of the weight detector αe is subtracted by the output of the weight detector can to offset the increase in weight of the pressurized tank (1).1. Powder can be transported continuously at a constant flow rate.

In this example, we will explain the case where the 11111 device CI8 has a memory calculation function, but as shown in Figure 4, the total gas flow rate or/and pressure tank/receiving device differential pressure or pressure tank The pressure may be controlled to be constant. That is, (4υ is a differential pressure calculator that is supplied with the output P of the pressurized tank pressure detector aη and the t11 force P of the receiving device pressure detector Qω, and obtains the differential pressure (RP*) between them. is a selection switching circuit which receives the output P1 of the detector 0η and the output of the differential pressure calculator and selects one of them.

(41 is a mass flow rate calculator which is supplied with the output QT of the glue supply gas flow rate detector (H) and the output cam PT of the transport pipe differential pressure detector (G), and calculates the flow rate based on these based on the quality of only the powder and granules; (
4a is a time differentiator for the output of tank weight detector αQ (to)
Output dw/dt differentiated by, nozzle differential pressure detector c! The output of Yu is multiplied by a constant K by 40 and output △PT
This is a selection switching circuit that interprets either the mass flow rate dw/dt determined as being proportional to the mass flow rate dw/dt and the output dw/di of the mass flow rate calculator (43).

((S is a mass flow controller that obtains 1lfI5 output by comparing the output of the selection switching circuit - and the desired mass flow rate set value, ■ is a selection switching circuit, G47) ) is a pressure setting gain adjuster and a bypass flow rate setting gain adjuster whose outputs correspond to the characteristic surfaces IIE and G in FIG. 2 through the selection switching circuit.

(49 is the pressure H barrel needle to which the output of the gain regulator (47) and selection switching circuit (4 points) is supplied, and this regulator (4!1fIh to pressurized flow rate supply line a
The switching circuit 611 inserted between the output side of the pressurized flow rate control valve αN) inserted between the control valve and the output side of the sentence selection switch circuit ■ is opened based on the output signal of the mass flow rate control needle. It is also possible to perform cascade control of the pressure regulator and the flow rate Mfti meter at the same time.

The device is a weight loss controller to which the output for setting the flow rate of the gain regulator and the output QB of the bypass flow rate detector Qυ are supplied, and from this iwmtim the flow rate 1M node connected to the bypass line Q4 is operated. Output is obtained.

Then, the selection switching circuit is operated so that the output of the differential pressure calculation winding is supplied to the pressure adjustment needle (to) K, and the selection switching circuit (44) is operated to change the output of the detector al19c14 and the controller (43). Select one of the outputs of , further switch the selection switching circuit) to the gain adjuster (46@), and adjust the gain adjuster Giη based on the characteristic curve E.
Therefore, it is possible to transport powder and granular materials at a constant flow rate while keeping the total supply flow rate constant, and in the same way, the selection switching circuit (to) is used for gain adjustment 1H4111K switching gain regulator (to) is set to the characteristics shown in Figure 2! i! Powder and granular material can be transported at a constant flow rate by keeping the pressure tank/receiving device differential pressure (p, -p,) constant by adjusting the pressure in accordance with G and K. In each of the above embodiments, explained the case in which the mass flow rate of powder or granular material is detected by the tank weight change chamber, the pressure loss at the transport pipe nozzle, the pressure loss between two distant points in the transport pipe, and the total supply gas flow rate. It is only necessary to detect one of them.

The differential pressure at the discharge nozzle may be detected by detecting the differential pressure between the lower part of the fluidized bed and the nozzle outlet, the differential pressure between the discharge nozzle and the outlet, and the differential pressure between the lower part of the fluidized bed and the inlet of the bypass pipe confluence. In particular, in the latter case, there is no need to perform a gas purge because the detection part is a gas phase part that does not contain powder or granules.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an example of the device of the present invention, and Fig. 2 is a system diagram for explaining the present invention. IrIA% Figure 3 is a system diagram showing another example of the device of the present invention, and Figures W and 4 are diagrams showing other examples of the control device. (1) is a pressurized tank, (3) is a fluidized bed, (6) is a transport pipe, (8) is a receiving device vQl is a pressurized gas supply source, al) is a flow rate control valve, hot water is a pressurizing fin, 0 is the flow rate N connection, αhiro is the bypass line, 翺 is the tank weight detector, αη is the pressurized tank pressure detector, -shiυ is the flow rate detector, (Foundation) is the differential pressure detector, (c) is Receiving device pressure detector, (2) is set value input device, (to) is control device.

Claims (1)

[Claims] Pressurized gas is supplied through the fluidized bed from a pressurized flow rate supply twin having a pressurization flow control valve to a fluidized bed type pressurized tank filled with powder and granules, and the powder and granules are fed to a transportation line connected to the pressurized tank K11I. In a high-pressure powder/granule gas pipe transport device that sends a constant flow of powder and granules to a receiving device, the transport line has a bypass flow control valve connected in parallel with the pressurized flow supply twin, and the powder and granules are discharged. A bypass line that fluid-dynamically controls the amount of gas, a pressurized pressure detector that detects the pressure inside the pressurized tank, and a total supply gas flow rate interposed in the pressurized flow rate supply line and the primary @ of the bypass line. Detector and bypass MTT test installed in the above bypass line? Jl device, a receiving pressure detector for detecting the internal pressure of the above-mentioned receiving device, a granular material discharge amount detector, a setting device for setting the powder and granular material discharge amount, air direction ratio, and pressurized gas flow rate, and the setting device. and a control device to which the outputs of the respective detectors are supplied and which controls the pressurized flow rate joint valve and the bypass flow rate joint valve, and is controlled to a desired powder and granule discharge value. Constant flow control device for powder and granular gas pipe transport equipment.