JPS6340237B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The disclosed technology belongs to the field of manufacturing technology for obtaining a slurry with a constant viscosity and stable properties when manufacturing a coal-heavy oil-based fuel slurry. <Summary of the Summary> The invention of this application feeds coal and heated heavy oil separately into a ball mill or the like, mixes them and pulverizes and disperses them to a predetermined concentration, particle size, and temperature, and at the same time removes the generated water vapor from the slurry. This invention relates to a manufacturing method that separates coal to obtain heavy oil-based slurry, and in particular, detects the amount of coal to be supplied and determines the amount of heavy oil to be supplied at a set ratio in accordance with this, thereby producing a product slurry. The temperature and the supplied heavy oil temperature are detected to heat the slurry to the set slurry temperature, and the moisture content of the coal is detected to determine the actual supply amount, and the corresponding actual amount of heavy oil is determined, so that coal heavy oil with optimal properties is determined. This invention relates to a manufacturing method for obtaining a system slurry. <Prior art> As is well known, various technologies such as so-called COM etc. have been developed and researched for coal heavy oil based slurry due to its advantages such as energy saving and high possibility of high rate transportation. . After coal is finely pulverized and mixed and dispersed with heavy oil to form a slurry, it is necessary to maintain stable properties not only during the manufacturing process, but also during the storage process, as well as during use. To deal with this, for example, there is a technology that heats and supplies heavy oil and performs various stabilization treatments on its properties, as shown in Japanese Patent Application Laid-Open No. 55-135196, which is a known prior art. be. By the way, the properties of various manufactured slurries include calorific value, specific gravity, flash point, temperature, viscosity, etc., but in the case of coal heavy oil based slurry, the slurry itself is liquid and is not suitable for transportation. ing. Therefore, the transport slurry has a capacity suitable for transport,
If the properties are lost, there will be a disadvantage that the specified amount of transportation cannot be secured. Therefore, it is the viscosity of the slurry that determines the fluidity of the slurry during transportation, and therefore, it can be seen that the viscosity is primarily the most important property of the coal-heavy oil-based slurry product. Incidentally, the factors that determine the viscosity of the slurry include the brand of coal, physical properties of the brand of heavy oil, coal concentration, particle size, slurry moisture, temperature, etc. Among them, concentration has the greatest influence on the properties. It is known that when the slurry temperature decreases, the viscosity increases and the above-mentioned troubles occur. In addition, viscosity increases when determining the crushing performance of wet ball mills used for producing coal and heavy oil based slurries. Of course, as mentioned above, in terms of the properties of coal and heavy oil, their moisture content plays a large role in determining their viscosity, but these are determined prior to feeding into the ball mill, etc., and the influence of moisture is minimal. Also, as the concentration of coal increases, the viscosity naturally increases. <Problems to be solved by the invention> However, in the production of coal-heavy oil-based slurry up to now, a predetermined coal-heavy oil supply ratio is determined in advance, and the heating temperature of the heavy oil is determined by measurement control using instruments, etc. Therefore, there was a problem in that it was not always possible to obtain a slurry with a uniform and stable temperature and viscosity. <Purpose of the Invention> The purpose of the invention of this application is to solve the problems of coal heavy oil based slurry based on the above-mentioned prior art, and to solve the problems of coal concentration, slurry temperature, and heavy oil slurry, which are most related to the viscosity of slurry. It is an object of the present invention to provide an excellent method for producing coal-heavy oil-based slurry that is beneficial to the field of fuel technology application in the energy industry by optimally controlling the supply temperature and obtaining slurry with stable properties. <Means/effects for solving the problems> In accordance with the above-mentioned object, the structure of the invention of this application, which is summarized in the above-mentioned claims, produces a stable coal-oil based slurry in order to solve the above-mentioned problems. At the same time, the set amount of coal to be supplied, as well as the moisture content, is detected, and the actual coal amount is constantly and stably supplied, and in response to this, the actual amount of heavy oil is supplied at a set ratio, and the temperature of the resulting slurry and the supplied heavy oil are A technical measure has been taken to detect the temperature of the supplied heavy oil and to obtain a slurry with stable properties and a constant viscosity by adjusting the supplied heavy oil temperature to a set value. <Example> Next, an example of the invention of this application will be described below with reference to the drawings. In the embodiment shown in FIG. 1, coal C is a predetermined quality brand, which is coarsely crushed to a predetermined particle size, dried, and supplied from a chute 1 via a quantitative supply conveyor 2 to a wet ball mill 3. The heavy oil L is also passed through a flow meter 5 and a flow rate regulating valve 6 by a pump 4, heated by a steam heater 7, and also supplied to the ball mill 3, where it is mixed at a constant temperature by a ball equipped in a predetermined manner, and the coal C is The slurry is finely pulverized to a set particle size, dispersed, and discharged from the rear containing mist and dehydrated steam.The mist, steam, and slurry are separated in the set separator 8, and the slurry S is auxiliary. tank 9
The water is then stored in a storage tank 11 by a pump 10. Therefore, the stabilization of the properties of the slurry S depends on the constant pulverized particle size in the mill 3 and the constant viscosity during dehydration and evaporation, that is, the concentration and temperature, so the concentration is controlled in the previous stage.
Further, temperature control is performed at a later stage. That is, the weight of the coal C supplied in a predetermined weight by the coal C constant supply conveyor 2 is detected via an appropriate weight detection device (not shown), and the detection signal is transmitted by the converter 12 to the set weight from the setting device 13. The signal is compared with the controller 14, and if the set weight is over or under, the control is adjusted accordingly, and the motor 15 of the constant supply conveyor 2 is controlled.
The amount of coal C supplied is made to match the set amount by slowing down the operation. On the other hand, the weight detection signal from the converter 12 is
The ratio setting signal is input to the control ratio setting device 16 and is compared with the flow rate signal from the flowmeter 5, and if there is an excess or deficiency with respect to the set ratio with respect to the amount of supplied coal C,
The excess/deficiency signal is used as a control output signal adjusted to a predetermined value by the controller 17, and the opening degree of the flow rate adjustment valve 6 is adjusted to determine the corresponding set flow rate.Therefore, the coal concentration is automatically kept constant at all times. be made to be Next, as shown in Figure 2, regarding the moisture in the slurry, as shown in zone A, coking coal whose moisture content is usually 7 to 12% is mixed with heated heavy oil and heated, and the horizontal axis If we take the temperature in °C and the moisture % in the slurry on the vertical axis, as shown in graph T, the moisture content decreases as the temperature rises, but if the temperature is kept constant, the moisture content in the slurry is determined. Therefore, there is no influence as a factor regarding the viscosity. However, complete control when there is a slight influence will be discussed later. Regarding temperature control, as shown in FIG. is input together with a signal from the setting device 21, detects the temperature difference set by the setting device 21, adjusts the excess and deficiency, and inputs it to the setting device 22,
On the other hand, the controller 2 receives a signal from the converter 23 of the detected temperature of the heavy oil heated and fed from the heater 7.
4, and its output signal is used as a control signal to open and close the flow rate regulating valve 26 of the steam feed pipe 25. As a result, the temperature of the slurry S is detected and the temperature of the heater 7 is controlled, and the heating temperature of the heavy oil L in the mill 3 is automatically maintained at the set temperature. Slurry can be manufactured while keeping the viscosity constant. A theoretical explanation of the slurry manufacturing method of the above embodiment, particularly the ratio calculation and setting of set values, is as follows. That is, in the case of the embodiment shown in Fig. 1, in the formula for calculating the ratio of coal and heavy oil, (1) Slurry production amount W _S (Kg/h) Slurry composition (weight ratio) Coal concentration C (%) Moisture content in slurry H _S ( %) Heavy oil concentration L (%) L=100-C-H _S (%) is determined as the production target value. (2) Coal moisture value H _C , moisture content in heavy oil H _L , heavy oil specific gravity γ
Analyze and find. (3) Next, calculate the coal supply amount (dry coal) W _CD = W _S × C/100 W _CD : Coal supply amount (dry coal) (Kg/h), and then (4) Coal supply amount ( Wet coal) W _C = W _CD / (100-H _C ) / 100 = W _S・C / 100-H _C W _C : Coal supply amount (wet coal) (Kg/h) H _C : Coal moisture (wet base) (%) and set this W _C to the coal feeder. (5) Next, calculate the coal supply ratio R _C = W _C /W _CX R _C : Coal supply ratio (-) W _CX : Maximum supply amount of the coal feeder (Kg/h), and perform the following (6) ), (7), and (8), and set the coal heavy oil ratio R in the ratio setting device. (6) Heavy oil supply amount W _L = W _S × L / 100 / (100-H _L ) / 100 = W _S × (100-C-
H _S )/100−H _L W _L : Heavy oil supply amount (Kg/h) H _L : Moisture in heavy oil (%) (7) Heavy oil supply ratio R _L = f(t)×W _L /γ/Q _LX R _L : Heavy oil supply ratio (-) f(t): Heavy oil flow meter temperature correction coefficient (-) γ: Heavy oil specific gravity (15℃/4℃) (-) Q _LX : Maximum supply amount of heavy oil feeder (/h) (8) Coal heavy oil ratio R = R _L / R _C = W _CX・f(t)・(1
00−C−H _S ) (100−H _C )/Q _LX・γ・C・(100−H _L ) (9) Moisture content in slurry determined as manufacturing target value
Read the product slurry temperature from Figure 2 so that it is H _S , and set it on the setting device. (10) Press the start button on the coal feeder to start production. (11) Heavy oil will be supplied according to the ratio set to the coal supply amount. (12) The heater is controlled so that the product slurry reaches the set temperature, and the heavy oil is heated and supplied. An example of slurry production based on the above process is shown in the following table.

[Table] In this production, each condition was as follows. (1) Maximum supply amount of coal feeder W _CX = 900 (Kg/h) (2) Maximum supply amount of heavy oil feeder Q _LX = 800 (/h) Heavy oil flow meter temperature correction coefficient f (t) = 1.0 ( -) (3) Wet ball mill specifications Mill diameter x Mill length = φ1200 x 2400 (mm) Ball filling rate 30% By the way, depending on the brand of Coal C, the moisture content strictly varies, and depending on the raw material. Moisture conditions may change frequently during feeding. Although it is relatively small compared to the change in the moisture content of coal C, the specific gravity of heavy oil L may also vary depending on the moisture content, etc. Also, since the heavy oil L is measured by volume, the change in coal C Changes in capacitance due to temperature may have a subtle effect on specific gravity concentration.
In addition, from a complete quality control perspective, slurry S
It is also necessary to manage the moisture inside the mill 3, and furthermore, considering the vaporized content due to evaporation of dehydrated water, it is necessary to keep the absolute humidity inside the mill 3 below a value corresponding to the amount of dehydrated water. Referring to FIG.
To explain with a diagram, control to keep the concentration ratio constant is performed by using a moisture meter 27 for raw coal C supplied from the chute 1 by means such as cycle sampling.
Detects the moisture content, compares it with the water content ratio set by the setting device 28 and calculates it in the calculator 29, converts the actual required amount of coal, and inputs the output to the coal amount control circuit 30 to control the operation of the quantitative supply conveyor 2. The weight of coal supplied from the supply conveyor 2 is inputted from the coal amount control circuit 30 to the ratio setting device 16. On the other hand, the moisture content of the heavy oil L fed through the pump 4 is similarly detected by a moisture meter 31 through cycle sampling, the temperature is detected by an appropriate sensor of a thermometer 32, and the specific gravity is also detected due to quality differences. The hydrometer 33 is used to transmit the detection signal together with the flow rate detection signal from the flowmeter 5 to the calculation circuit 34.The moisture content of the final product slurry S is detected by the moisture meter 35, and the detection signal is sent to the calculation circuit 34. Feed back to the circuit 34, calculate the total amount to convert the actual amount of heavy oil, and send the conversion signal to the ratio setting device 16 to determine the actual amount of heavy oil with respect to the actual amount of coal,
The flow rate adjustment valve 6 determines the flow rate with the controller 17.
Open and close as required. Therefore, this embodiment ensures that the concentration is automatically controlled. In this case, the evaporation of the contained water by dehydration is uniquely determined by the temperature based on the above-mentioned FIG. 2, and the temperature control for the heater 7 is performed by the first
Slurry S
viscosity uniformity is ensured. The mist and steam separated by the separator 8 are separated into mist M and steam by the diffuser 36, the mist M is treated as appropriate, and the steam is sent to the damper 37 and the blower 3.
8 and is dissipated by the exhaust tower 39. Therefore, as mentioned above, in order to perform sufficient dehydration in Mill 3, it is necessary to reduce the absolute humidity inside the mill to a value corresponding to the amount of dehydration or less, and to do this, it is necessary to ensure the amount of ventilation in the mill. It is considered a condition. In this embodiment, the suction negative pressure at the inlet of the mill 3 is detected by a differential pressure gauge 40, the signal from the converter 41 is compared with the signal from the setting device 42, and the controller 43
The throttle amount of the damper 37 is controlled via the damper 37, thereby controlling the amount of ventilation inside the mill 3. Therefore, regarding the embodiment shown in FIG.
The slurry manufacturing process will be explained in the same manner as in the embodiment shown in the figure: (1') Item (1) above is determined as the manufacturing target value. (2′) Calculate the above item (2) and set W _CD to the coal feeder. (3') The arithmetic unit 29 has each device constant W _CX ,
Q _LX and f(t) have been input, and a new target value, coal concentration C, is input. (4′) Moisture content in slurry determined as manufacturing target value
Read the product slurry temperature from Figure 2 so that it is H _S , and set it on the setting device. (5') Set the mill inlet intake static pressure so that water can evaporate sufficiently in the mill. (6′) Press the start button on the coal feeder to start production. (7′) The data from each detector is instantly sent to the arithmetic circuit.
and is input to the arithmetic unit, and the above-mentioned items (1) to (8) are
The calculations shown above are performed, and heavy oil is supplied according to the calculated coal/heavy oil ratio R. (8′) The heater is controlled so that the product slurry reaches the set temperature, and the heavy oil is heated and supplied. An example of slurry production based on the above process is shown in the following table.

[Table] It goes without saying that the embodiments of the invention of this application are not limited to the above-mentioned embodiments, and various other embodiments can be adopted. <Effects of the Invention> As described above, according to the invention of this application, in the coal heavy oil based slurry manufacturing method, the heavy oil is controlled to be supplied at a constant ratio to the amount of supplied coal, and at the same time, the temperature of the product slurry is detected. By feeding back the amount and maintaining the heating temperature of heavy oil at the set temperature, the concentration and temperature, which have the deepest relationship to the viscosity of the slurry, are always kept constant, and as a result, the viscosity changes from the constant viscosity. Not only does it maintain optimal performance for transportation, but it also has the excellent effect of not placing unnecessary loads on pumps and mills, and preventing unnecessary temperature rises and energy loss. Furthermore, since the viscosity can be maintained constant, the mill function can be performed as designed, the crushed particle size can be made uniform as planned, and the quality of the slurry can be improved. Furthermore, the moisture content in the supplied coal is detected to control the actual design coal feed amount, and the above temperature control is performed by substantially controlling the heavy oil supply amount at a constant ratio to the designed coal feed amount. By doing so, the effective concentration of the slurry can be determined reliably and precisely, and there is an excellent effect that a coal heavy oil slurry with more stable quality can be obtained.

[Brief explanation of the drawing]

The drawings are explanatory diagrams of embodiments of the invention of this application, and FIG. 1 is a schematic diagram of one embodiment, FIG. 2 is an explanatory diagram of temperature and slurry water content, and FIG. 3 is an explanatory diagram of another embodiment. It is. C...Coal, L...Heavy oil, M...Mist, V...
...Steam, S...slurry.

Claims (1)

[Scope of Claims] 1. A manufacturing method in which coal and heated heavy oil are mixed and pulverized and dispersed, and at the same time, mist water vapor is separated to obtain a coal heavy oil-based slurry, which detects the coal supply amount and responds to a set ratio. The amount of heavy oil supplied is controlled by the above-mentioned method, and the temperature of the coal heavy oil based slurry and the supplied heavy oil are detected and compared, and the supplied heavy oil is heated to a set temperature to stabilize the properties of the slurry. Coal heavy oil based slurry manufacturing method. 2. In a production method in which coal and heated heavy oil are mixed and pulverized and dispersed, and at the same time, mist water vapor is separated to obtain a coal heavy oil slurry, a set amount of coal is supplied by detecting and calculating the moisture content from the supplied coal. At the same time, the fuel oil supply amount is controlled at a set ratio to the set coal supply amount, and the temperature of the coal heavy oil slurry and the supplied heavy oil are detected and compared, and the supplied heavy oil is heated to the set temperature to make the slurry. A method for producing a coal/heavy oil slurry characterized by stabilizing its properties.