JPH0132278B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The disclosed technology belongs to the technical field of obtaining a stable slurry with a constant viscosity for producing coal heavy oil-based slurry. <Summary of the gist> This invention supplies coal and heated heavy oil separately to a ball mill or the like, mixes them, pulverizes and disperses them to a predetermined concentration, particle size, and temperature, and simultaneously removes generated mist and water vapor from the slurry. This invention relates to a method for producing a coal heavy oil slurry in which coal is separated to obtain a coal heavy oil slurry.In particular, the amount of coal to be supplied is detected, and correspondingly, the amount of heavy oil to be supplied at a set ratio is set at a pre-heating stage. Then, the determined supply amount of heavy oil is heated, the temperature is detected before the crushing process, and compared with the set temperature, and the temperature of the supplied heavy oil is controlled by controlling the heating temperature. This invention relates to a method for producing a coal/heavy oil slurry that obtains a coal/heavy oil slurry with constant and optimum properties. <Prior Art> As is well known, various technologies, such as so-called COM, have been continuously developed and improved for coal heavy oil based slurry for its advantages such as energy saving and high transportability. In such a coal/heavy oil based slurry, it is necessary to finely pulverize the coal and mix and disperse it with the heavy oil to maintain stable properties not only during the manufacturing process but also during the storage process and during use. To deal with this, for example, there is a technology that supplies coal and heavy oil in balanced amounts and performs various stabilization treatments, as shown in Japanese Patent Application Laid-open No. 135196/1983, which is a known prior art. be. By the way, although the property factors for the slurry produced include evaporation rate, specific gravity, flash point, temperature, viscosity, etc., coal heavy oil based slurry is liquid in its own state and is suitable for transportation. Therefore, as a matter of course, if the transport slurry lacks the ability and properties suitable for transport, there will be a disadvantage that the amount of transport cannot be secured. Therefore, it is the viscosity that determines the fluidity related to slurry transportation, and therefore, it is understood that the viscosity is primarily important as a property of the coal heavy oil slurry product. Factors that determine the viscosity of the slurry include the physical properties of coal and heavy oil, coal concentration, particle size, moisture content in the slurry, temperature, etc., but the most influential factors are concentration and temperature. It is known that when the viscosity decreases, the viscosity increases, causing the above-mentioned troubles. In addition, viscosity plays a large role in determining the grinding performance of, for example, a wet ball mill that is used to produce coal or heavy oil based slurry. <Problems to be solved by the invention> Of course, as mentioned above, due to the properties of coal and heavy oil,
Moisture and other factors also play a role in determining viscosity, but these are determined prior to charging, and the influence of moisture is slight. Also, as the coal concentration increases, the viscosity naturally increases. However, in the production of coal-heavy oil-based slurry so far, the coal-heavy oil supply ratio was determined in advance, and the heavy oil temperature was also determined in advance, but due to various disturbance conditions, it is not possible to create a slurry with a uniform and stable temperature and viscosity. I had a problem where I couldn't get it. <Object of the invention> The object of the invention is to solve the problems of coal heavy oil based slurry based on the above-mentioned prior art as a technical problem, and to improve the coal concentration which is most related to the viscosity of the slurry.
At the same time, it is an object of the present invention to provide an excellent method for producing coal-based heavy oil-based slurry that is beneficial to the field of fuel technology application in the energy industry by optimally controlling the temperature of the supplied heavy oil and obtaining a slurry with stable properties. It is. <Means/effects for solving the problems> In order to solve the above-mentioned problems, the configuration of the present invention, which is based on the above-mentioned claims, detects the amount of coal to be supplied and adjusts it to the set planned amount. Compare,
It automatically supplies the set amount, and also detects the amount of heavy oil to be supplied for that detected amount and automatically sets it to the set amount, and also automatically adjusts the temperature of the heavy oil after heating to the set temperature. This technology takes technical measures to control the viscosity and obtain a slurry with stable properties and a set viscosity. <Example> Next, an example of the present invention will be described below with reference to the drawings. In the illustrated plant, coal C is of a predetermined quality brand and is coarsely crushed to a preset viscosity.
is supplied to the wet ball mill 3 via the quantitative supply conveyor 2, and at the same time, a predetermined type of heavy oil L is also passed through the flow meter 5 and the flow rate adjustment valve 6 by the pump 4.
The coal is heated by the steam heater 7, is also supplied to the ball mill 3, is mixed at a constant temperature by a predetermined ball (not shown), is pulverized to a set viscosity, is dispersed in heavy oil, and becomes a slurry. It is discharged from the rear part in a state containing mist and dehydrated steam, and in the setting separator 8, the mist and
The steam and slurry are separated, and the slurry S is stored in a storage tank 11 by a pump 10 via an auxiliary tank 9. The stabilization of the properties of the slurry S, the constant pulverization particle size in the mill 3, and the dehydration and evaporation depend on the conditions of constant viscosity, that is, the conditions of concentration and temperature. Temperature control is performed after the heater. That is, for the coal C supplied in a predetermined weight by the coal quantitative supply conveyor 2, the supplied weight is detected at a predetermined value via an appropriate weight detection device (not shown), and the detection signal is sent to the setting device 13 by the converter 12.
The controller 14 compares and calculates the set weight signal from the controller 14, and if the set weight is over or under the set weight, the control is adjusted accordingly, and the operation of the motor 15 of the quantitative supply conveyor 2 is controlled at a slow speed to reduce the supply coal. Make the amount of C match the set amount. On the other hand, the weight detection signal from the converter 12 is input to the ratio setting device 16 for heavy oil control, and the ratio setting signal is compared with the flow rate signal from the flow meter 6. If there is an excess or deficiency in the set ratio with respect to the amount of coal to be supplied, The excess/deficiency signal is used as a control output signal adjusted to a predetermined value by the regulator 17, and the opening degree of the flow rate adjustment valve 6 is adjusted to determine the corresponding set flow rate of heavy oil L, and the concentration of coal C is automatically maintained constant. be made to be done. As for temperature control, the temperature of the heavy oil is detected by appropriate sensors in the process of passing through the heater 7 and being supplied to the ball mill 3, and the detection signal is converted into an electric signal by the converter 18, and the temperature is sent to the setting device 19.
is input to the controller 20 together with the set temperature signal from the setter 19, and adjusted for excess or deficiency with the set temperature signal from the setter 19, and the adjusted output signal adjusted by the controller 20 is input to the steam feed pipe 21 as a control signal. The flow control valve 22 is opened and closed. 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, so that the slurry maintains a constant viscosity. can be manufactured. Further, the mist and steam separated from the separator 8 are separated into mist M and steam by the diffuser 22, the mist M is appropriately treated, and the steam is sent to the atmosphere from the exhaust tower 25 via the damper 23 and the blower 24. released. Thus, a slurry manufacturing method according to the above embodiments,
In particular, setting of set values will be theoretically explained as follows. 1 First, the following item 2) is determined as the manufacturing target value. 2 Slurry production amount Ws (Kg/h) Slurry composition (weight ratio) Coal concentration C (%) Heavy oil concentration L (%) Moisture content in slurry H (%) C+L+H=100 (%) 3 Coal moisture value Hc, and Analyze and find the heavy oil specific weight γ. 4 Find and set Wc from the following item 5). 5 Coal supply amount (wet coal) W _C = W _S × C/100/(100−H _C )/100=W _S・C/100−
H _C Wc: Coal supply amount (Kg/h) Hc: Coal moisture (wet base) (%) 6 Then, calculate the following items 7) and 8), and calculate the following items 7) and 8).
Find the term R and set it in the ratio setting device. 7 Heavy oil supply amount W _L = W _S × L / 100 = W _S × 100-C-H / 100 W _L : Heavy oil supply amount (Kg/h) 8 Supply ratio R _c = W _C /W _CX R _C : Coal Supply ratio (-) W _CX : Maximum supply amount of coal feeder (Kg/h) R _L = W _L /γ/Q _LX = W _L /Q _LX・γ R _L : Heavy oil supply ratio (-) γ: Heavy oil Specific gravity (-) Q _LX : Maximum supply amount of heavy oil feeder (l/h) 9 Coal/heavy oil ratio setting value R R = R _L /R _C = W _CX /Q _LX・γ・ (100−C−H) (100−H _C )/100・C 10 For heavy oil temperature setting, set the actual value if available. If there is no actual value, calculate the heat balance, initialize the calculated value, compare the moisture in the slurry to be manufactured and the temperature of the product slurry with the target value in item 2) above, and then set the set value. Review and reconfigure if necessary. 11 Press the start button on the coal feeder to start production. 12 Heavy oil is supplied according to the ratio setting value set for the coal supply amount. Production examples based on the above-mentioned process are shown in the following table.

[Table] In this production, each condition was as follows. 1 Maximum supply amount of coal feeder W _CX = 90 (Kg/h) 2 Maximum supply amount of heavy oil feeder Q _LX = 80 (l/h) 3 Wet ball mill specifications Mill diameter x Mill length = φ330 x 1000 (mm) Ball filling rate: 30% It goes without saying that the embodiments of the present invention 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 present invention, in the method for producing coal heavy oil slurry, heavy oil is controlled to be supplied at a constant ratio to the amount of coal to be supplied, and the temperature of the heated heavy oil is controlled at the same time as the supply to the mill. By detecting in the previous stage and feeding back the detected amount to the heater to maintain the heavy oil heating temperature at the set temperature, the concentration and temperature, which have the deepest relationship with the viscosity of the slurry, are always kept constant. As a result, the viscosity of the slurry is maintained at the set viscosity, and not only does it exhibit optimal properties for transportation, but it also avoids placing unnecessary load on the transportation pump.
Moreover, it has the excellent effect of preventing unnecessary temperature rise and energy loss. Furthermore, since the viscosity can be maintained constant, the function of the mill can be performed as designed, the crushed particle size can be made uniform as planned, and the quality of the slurry can be improved.

[Brief explanation of drawings]

The drawing is a schematic diagram of one embodiment of the invention. C...Coal, L...Heavy oil, M...Mist, S...Slurry.

Claims (1)

[Claims] 1. In a method for producing coal and heavy oil slurry, in which coal and heated heavy oil are mixed, pulverized, dispersed, and separated into mist and water vapor to obtain a slurry, the amount of coal supplied is detected and the amount of coal and heavy oil is mixed. The amount of heavy oil supplied is controlled according to the set ratio,
Further, the coal is characterized in that the supplied heavy oil is heated and compared with a set temperature before being sent to the coal pulverization process, and the heating temperature for the supplied heavy oil is controlled to bring the supplied heavy oil to the set temperature. Heavy oil based slurry manufacturing method.