JP5332245B2 - How to operate the crusher - Google Patents

Description

  The present invention relates to an operation method of a pulverizer that pulverizes a mixture mixed with biomass to produce a solid fuel, and more particularly to an operation method of a pulverizer that can perform cleaning on a table in the pulverizer during operation. .

In response to the increasing demand for energy and the growing awareness of global environmental issues in recent years, combustion is performed using solid fuel such as fine biomass fuel instead of fossil fuel such as coal. Development of a combustion apparatus (see Patent Document 1) used in industrial furnaces such as boilers and kilns is underway.
JP 2005-48967 A

  For example, when biomass is used, foreign objects such as nails are often included. For this reason, metal foreign substances or the like stay on the table of the pulverizer provided in the equipment including the combustion device as disclosed in Patent Document 1 described above, and the pulverization efficiency of the pulverizer is reduced. There is a possibility that the wear of the table liner and the like will progress. Therefore, it is necessary to stop the operation of the pulverizer, enter the pulverizer, clean the foreign matter on the table, etc., and work for a long time in a harsh environment (hot, dusty) in the pulverizer. Be strong. In addition, the pulverizer is stopped for a long time, resulting in a decrease in production. Thus, there is a problem that the table on the crusher cannot be efficiently cleaned when the crusher is in operation.

  The present invention has been made in view of such problems, and cleans the pulverizer efficiently at low cost while the pulverizer is in operation, prevents a decrease in pulverization efficiency due to metal foreign matter staying on the table, and An object of the present invention is to provide a method of operating a crusher that can reduce the progress of wear of a crushing roller and a table liner.

  In order to achieve the above object, an operation method of a pulverizer according to the present invention is an operation method of a pulverizer that generates a solid fuel by pulverizing a mixture in which biomass is mixed. A charging stop step of stopping the charging of the mixture into the pulverizer at the timing of the above, and a holding amount detecting step of detecting the holding amount of the mixture in the pulverizer after stopping the charging of the mixture in the charging stopping step And when the retained amount of the mixture detected in the retained amount detection step becomes equal to or less than a predetermined amount, the air amount restricting step for restricting the exhaust air amount from the pulverizer, and the exhausted air amount in the air amount restricting step. A time lapse determining step for determining whether or not a predetermined time has passed since the squeezing is performed, and when it is determined that the predetermined time has elapsed in the time lapse determining step, Said discharge With return amount based on, characterized in that it comprises a resuming turned resuming step the insertion of the mixture to that stopped the pulverizer at the closing stop process.

  The operation method of the pulverizer according to the present invention is configured as described above, so that when the amount of the mixture in the pulverizer becomes equal to or less than a predetermined amount while the charging of the mixture is stopped during the operation of the pulverizer. The remaining mixture in the pulverizer can be effectively removed by continuing the operation for a predetermined time after reducing the amount of air discharged from the pulverizer (that is, continuing to drive the table or the like). Thereby, the cleaning on the table in the pulverizer can be efficiently performed at low cost while the pulverizer is operated.

  The biomass is preferably woody biomass.

According to the present invention, an effect that it is possible to provide a method of operating a grinding machine that can increase the efficiency perform cleaning on leaving grinder table was operated grinder at a low cost.

  Hereinafter, a method for operating a crusher according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an explanatory diagram for explaining an example of the entire configuration of a solid fuel production combustion facility to which a pulverizer operating method according to an embodiment of the present invention is applied. As shown in FIG. 1, in the production combustion facility 100, first, for example, a mixture that is a material of solid fuel mixed with biomass is introduced into a receiving hopper from a truck or the like (not shown). Here, the biomass refers to woody biomass such as construction waste, forest felled trees, and bark, and food biomass such as rice husk and coffee straw. As the biomass, a single product or a mixed product obtained by mixing a plurality of products can be used. Among these, in this invention, woody biomass can be used conveniently.

  Note that dust in the air in the receiving hopper accompanying the introduction of the mixture is collected by a dust collector (not shown).

  The mixture put into the receiving hopper is stirred and conveyed at a predetermined conveyance speed by a screw feeder (not shown), and impurities in the mixture are removed via a disk screen. Through the supply hopper 11 and stored.

  In addition, large magnetic bodies such as iron pieces are removed from the mixture discharged from the disk screen by a magnetic separator (not shown) during conveyance by the belt conveyor. In a magnetic separator, it is particularly difficult to completely remove small magnetic materials, and they are put into a pulverizer. In addition, a non-magnetic metal such as aluminum is not removed and is put into a pulverizer. The mixture stored in the supply hopper 11 in this manner is discharged to the weighing belt conveyor 13 by a predetermined amount via the supply feeder 12 and further quantified by the weighing belt conveyor 13 and then pulverized via the double flap gate 14. Is supplied to a vertical roller mill 30 as a machine.

  In the vertical roller mill 30, the charged mixture is finely pulverized by the grinding action between the table liner 31 and the mill roller 32 fixedly laid on the table. The table liner 31 is driven by a drive motor (not shown) so as to make a circular rotational movement about a rotating shaft standing in the vertical direction. The mill roller 32 is rotationally driven so that the side surface of the mill roller 32 contacts the liner surface of the table liner 31 via the pulverized material. In the vertical roller mill 30, among the pulverized mixture, the pulverized lightweight powder is air-fed upward by hot air P supplied by the pressure fan 28 into the vertical roller mill 30, and is a rotary classifier. 33 is distinguished on the basis of particle diameter, density, shape, etc., and is sucked out (discharged) as a solid fuel by a mill fan 35 and supplied to a cyclone 34 as a powder separator.

  In the vertical mill roller 30, the pressing force (pressing force) of the mill roller 32 to the table liner 31 is adjusted by the valve unit 25, the roller pressurizing pump 26 and the oil unit 27. This pressure is monitored sequentially by the pressure gauge 24.

  In the cyclone 34, the solid fuel transported by air is separated from the air, and the separated air is supplied to the bag filter 40 by the mill fan 35 and is sent to an environmental facility (not shown) after dust and the like are removed. Is sent to the exhaust side of the pressure fan 28. The mill fan 35 is driven by a drive motor 37 that is motively connected through a fluid coupling 36, for example.

  On the other hand, the solid fuel (biomass powder) separated from the air in the cyclone 34 falls downward and is sent to the distributor 39 by the transport blower 29, and then the number of combustion burners (not shown) provided in the combustion boiler 41. And is used as fuel in the combustion boiler 41.

  The dust removed by the bag filter 40 is sent together with the solid fuel from the cyclone 34 by the feeder 42 to the distributor 39 and used as the above-described solid fuel. Further, in the production combustion facility 100 of this example, pulverized coal is further mixed with the solid fuel distributed via the distributor 39 and used as fuel in the combustion boiler 41.

  The exhaust gas S in the combustion boiler 41 is exhausted from the combustion boiler 41, a part of which is supplied to the hot gas cyclone 38, where it is separated into hot air P and soot, and the separated soot is While being sent to environmental equipment (not shown), the hot air P is supplied into the vertical roller mill 30. Therefore, in the production combustion facility 100 of this example, the biomass is not only finely pulverized but also sufficiently dried by the hot air P from the pressure fan 28 in the vertical roller mill 30.

  Next, the cleaning operation process of the vertical roller mill 30 of the production combustion facility 100 configured as described above will be described. FIG. 2 is a flowchart showing an example of a cleaning operation processing procedure of the vertical roller mill 30 of the manufacturing combustion facility 100. In addition, it is assumed that the same reference numerals are attached to portions that are already described, and the description may be omitted. Here, in order to simplify the description, the description will be made except for the processing particularly related to the present invention. It may be omitted. Here, the mixture supplied to the vertical roller mill 30 will be described as wood chips in particular.

  As shown in FIG. 2, first, the supply of wood chips into the vertical roller mill 30 in operation is stopped at an arbitrary timing for cleaning the vertical roller mill 30 (step S101). Next, wait until the retained amount of wood chips in the vertical roller mill 30 becomes almost zero (N in step S102), and if the retained amount becomes almost zero (Y in step S102), the airflow of the mill fan 35 (Step S103).

  Here, it is determined whether or not the air volume of the mill fan 35 is substantially zero (step S104). If it is determined that the air volume is not substantially zero (N in step S104), the process proceeds to step S103. The air volume of the mill fan 35 is reduced. When it is determined that the air volume has become substantially zero (Y in step S104), the operation of the vertical roller mill 30 is continued with the air volume of the mill fan 35 being substantially zero.

  Then, while the operation is continued, after the air volume of the mill fan 35 is reduced to almost zero, for example, it is determined whether or not a cleaning operation time of 5 minutes to 10 minutes as a preset predetermined time has elapsed (step) S105) Wait until the cleaning operation time elapses (N in step S105). If the cleaning operation time elapses (Y in step S105), the air volume of the mill fan 35 is returned to the original state (step S106). The supply of wood chips into the roller mill 30 is resumed (step S107), and a series of cleaning operation processing according to this flowchart is completed.

  By performing such a cleaning operation process, it is possible to efficiently remove foreign matters such as metal particles staying in the vertical roller mill 30 (particularly, foreign matters remaining on the liner surface of the table liner 31). It becomes possible. Moreover, since the foreign matter inside can be effectively removed while the operation of the saddle type roller mill 30 is continued, it can be operated at low cost.

  In the cleaning operation process, specifically, the following operation is automatically performed by a program. First, in the processing related to the wood chip supply stop in step S101, the supply feeder 12 is stopped to lower the mill differential pressure (difference between the supply wind pressure and the discharge wind pressure) and to suppress the increase in the mill outlet temperature. The pressure fan inlet damper 18 is fully closed. At the same time, the weighing belt conveyor 13 is stopped and the double flap gate 14 is stopped.

Next, in the processing relating to the amount of wood waste retained in step S102 and the air volume of the mill fan 35 in S103 and S104, for example, whether or not the conveying pressure of biomass powder in the conveying blower 29 has decreased to, for example, 8.5 kPa. After confirming with the conveyance pressure gauge 20, the position (MV value) of the rake pipe 21 before the operation is stored, and the output of the fluid coupling 36 is set to 0%. At the same time, the opening degree of the mill fan inlet damper 22 is set to 5%, and the air volume is set to 10 kNm ³ / h by the air flow meter 23.

  Then, in the process relating to the determination of the elapse of the predetermined time in step S <b> 105, for example, the cleaning operation time stands by for 5 minutes and the metal particles are discharged from the wood flour mill pyrite 15. At this time, when the mill outlet thermometer 16 raises the mill outlet temperature or the bag filter thermometer 17 raises the bag filter temperature, the pyrite gate 15 is opened.

  Finally, in the processing related to the wood chip supply resumption in step S106, the fluid coupling 36 is returned to the position (MV value) of the rake pipe 21 before the operation.

At the same time, for example, the rotational speed of the rotary classifier 33 is set to 1,700 rpm, the pressing force of the mill roller 32 is set to 3.5 kPa with the pressure gauge 24, and the discharged air volume is set to 67 kNm ³ / h with the air volume meter 23. Set as follows. Then, the double flap gate 14 and the weighing belt conveyor 13 are operated, the supply feeder 12 is operated, and charging is resumed so that the wood waste supply amount MV value becomes 10%. In addition, since the data such as the above values are data suitable for the production combustion facility 100 of the present example, they are appropriately changed when the facility scale, operating conditions, and the like change.

  Thus, by operating the vertical roller mill 30 during the operation of the production combustion facility 100, the present applicant was able to obtain the following results. Table 1 shows operating conditions of the vertical roller mill 30 before and after the cleaning performed by the applicant.

  The crushing capacity of the vertical roller mill 30 is 13 t / h. Moreover, construction waste (water 13-35% apparent specific gravity 0.18-0.23 t / m3) was used as biomass.

  Table 2 shows the operation status regarding the electric power of the vertical roller mill 30 before and after the cleaning.

  As described above, in Tables 1 and 2, the effect before and after the cleaning is most noticeable in the mill differential pressure (pressure difference between the inlet side and the discharge side of the vertical roller mill 30). By carrying out the cleaning, the mill differential pressure is reduced by about 21% on average (ie, the amount of wood powder held in the mill is reduced, indicating that grinding is performed efficiently). . In addition, the dry pulverization amount (the pulverization amount in absolute drying) is increased by about 15% on average (that is, the pulverization efficiency is improved), and the power consumption (total) is reduced by about 14% on average (that is, power saving). I found out that

  Further, Table 3 shows the results of measurement of the wear condition of the table liner 31 before and after the cleaning, showing the effect of reducing the wear of the table liner 31 and the mill roller 32 of the vertical roller mill 30 by performing the cleaning.

  In Table 3, measurement locations A, B, C, and D represent arbitrary locations on the liner surface of the table liner 31. According to this, the wear of the table liner 31 is reduced by about 40% in terms of the average wear unit (that is, the wear can be suppressed by performing the cleaning).

  As described above, according to the operation method of the pulverizer according to the present embodiment, it is possible to efficiently clean the internal table at a low cost while operating the vertical roller mill 30.

It is explanatory drawing for demonstrating an example of the whole structure of the manufacture combustion equipment of the solid fuel to which the operating method of the grinder which concerns on one embodiment of this invention was applied. 3 is a flowchart showing an example of a cleaning operation processing procedure of a vertical roller mill 30 of the manufacturing combustion facility 100.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Supply hopper, 12 ... Supply feeder, 13 ... Weighing belt conveyor, 14 ... Double flap gate, 15 ... Pyrite gate, 16 ... Mill exit thermometer, 17 ... Bag filter thermometer, 18 ... Pressure fan inlet damper, 19 Recycle damper, 20 Transport pressure gauge, 21 Drake pipe, 22 Mill fan inlet damper, 23 Air flow meter, 24 Pressure gauge, 25 Valve unit, 26 Roller pressure pump, 27 Oil unit, 28 DESCRIPTION OF SYMBOLS ... Pressure fan, 29 ... Conveyance blower, 30 ... Vertical roller mill, 31 ... Table and table liner, 32 ... Mill roller, 33 ... Rotary classifier, 34 ... Cyclone, 35 ... Mill fan, 36 ... Fluid coupling, 37 ... Drive Motor, 38 ... hot gas cyclone, 39 ... distributor, 40 ... bag filter, 41 ... combustion boiler, 42 ... feeder.

Claims (2)

A method of operating a pulverizer that pulverizes a mixture mixed with biomass to produce a solid fuel,
Supply means for supplying the biomass to the crusher;
A holding amount detecting means for detecting a biomass holding amount in the crusher;
Sorting means for wind-sorting biomass in the pulverizer and discharging from the pulverizer;
An air volume adjusting means for adjusting the air volume in the selecting means;
Supply control means for executing or stopping the supply of the biomass by controlling the supply means;
Have
A charging stop step for stopping charging of the mixture into the pulverizer at an arbitrary timing during operation of the pulverizer;
A holding amount detection step of detecting a holding amount of the mixture in the pulverizer after stopping the charging of the mixture in the charging stop step;
An air volume throttling step of reducing the amount of air discharged from the crusher when the amount of the mixture detected in the possession amount detection step is equal to or less than a predetermined amount;
A time lapse determination step of determining whether or not a predetermined time has elapsed since the discharge air volume was reduced in the air volume reduction step;
When it is determined in the time elapse determination step that the predetermined time has elapsed, the exhaust air volume throttled in the air volume throttling step is restored and the inside of the pulverizer stopped in the charging stop step And a charging restarting step of restarting charging of the mixture into the pulverizer.   The method for operating a pulverizer according to claim 1, wherein the biomass is woody biomass.

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