DE3320264A1 - Raw coal comminuting system and apparatus for performing the process - Google Patents

Abstract

Raw coal is usually milled in ball or bowl mill crushers, in order e.g. to be able to operate appropriate burners with the coal dust, as used in industries which use thermal production processes. The specific electrical energy requirement is particularly high for ball mills, since the preponderant portion of the energy is required solely to set the milling bodies in the mill in motion. The milled product filling which is pulverised between the milling bodies amounts to only a fraction of the weight of the milling bodies. Coal residues necessarily remain in the system when the described milling system is stopped, and can only be removed by milling empty for hours, through which on the other hand damage to the steel cladding of the ball mills or destruction of the milling plate in bowl mill crushers can occur, so that the danger of a self-ignition or detonation can arise from coal residues remaining in the systems. These disadvantages are to be prevented, as proposed according to the invention, in that the raw coal is disintegrated in two stages in comminuting devices with rotating comminuting tools, in that the conveyance is effected by a gas stream, and in that the coarse grains arising in the first comminuting stage are fed to a second comminuting stage. With the proposed comminuting system, the raw coal can ... Original abstract incomplete.

Description

Description 1 tipping hopper or intermediate bunker 2 discharge belt 3 transport belt 4 lifting magnet 5 pendulum sluice 6 pipeline of the gas circuit 7 supply of hot gas 8 Crushing device of the first stage 9 Riser pipe 10 Sifter 11 Connection line 12 Changeover flap 13 Second stage shredding device 14 Separator 15 Rotary feeder 16 Storage silo 17 Pressure cell 18 Fan of the gas circuit 19 Bypass 20 dedusting system with fan 21 adjustable flap in the gas leading Pipeline 22 adjustable valve in the gas-carrying pipeline 23 bypass after the Entstaubungsanige 24 bursting discs The raw coal is extracted from a tilting funnel or Intermediate bunker 1 via a discharge belt 2 and a conveyor belt 3 to the shredding system Abandoned directly over the transport hand 3 running with a small load a lifting magnet 4 arranged to withstand reacting Fresd bodies, so that it is in the shredding equipment cannot produce a spark.

At the raw coal inlet into the comminution system is for the purpose of air exclusion a pendulum lock 5 is arranged.

The shredding system consists of a gas circuit 5 in pipelines, in which the individual machines are arranged.

Below the pendulum lock 5, hot gases 7 are fed into the shredding system introduced, so that the crushing device arranged below the first Stage 8 is charged with RohkohleS cycle gas and hot gas. There is a Shredding and drying process.

The raw coal crushed in the crushing device õ is pneumatically discharged and fed to the classifier 10 via a riser pipe 9. In the adjustable sifter 10 is a grain class separation.

The coarser than required grain class is made via a connecting line 11, in which a changeover flap 12 is located, of the shredding device the second stage 13 is fed. The shredded material discharge goes to the riser pipe 9 supplied.

In terms of the method, the second comminution stage can also be the comminution device 8, which then through the changeover flap 12 and the connecting line 11 accordingly is charged.

The required grain class is obtained with the gas flow from the classifier 10 discharged and fed to a separator 14, depending on the total output, also several. The coal dust separated in the separator 14 is passed through a Zelienrad sluice 15 discharged and stored in a storage silo 16.

The storage silo 16 is mounted on pressure cans 17 and controls via a adjustable setpoint the feed quantity into the shredding water sJrsteaD It is a Advantage of shredding devices with rotating shredding tools compared to ball mills or vertical roller mills that the feed quantity is irrelevant is, if it is only below the designed maximum power, results from this Another advantage is that the newly proposed shredding system takes place at the same time be operated to consume the coal dust. can. and not constantly on or must be turned off, z, B, with reduced coal dust requirement, because just in the Periods of A and shutdown the risk of a coal dust explosion greatest is, On the other hand, by changing the setpoint of the pressure cells 17 in the Storage silo 16 an increased supply of coal dust can be created.

After the separator 14, a fan 18 is arranged in the gas circuit, which supplies the circulating gases back to the shredding device 8 The pipeline between the fan 18 and the shredding device 8 is a bypass 19 provided, via which the connection to a dedusting system 20 exists. On the one hand, the very fine coal particles are removed from the gas cycle in the dedusting system deposited, on the other hand by the drying process in the shredding system discharged vapors.

The coal dust that arises in the dedusting system is put into the storage silo 16 transported The gases discharged from the gas cycle are transported accordingly supplied hot gases 7 replaced. The adjustment flaps 21/22 are automatically activated Controlled temperature measuring devices, which in the gas circuit before entering the shredding device 8 and after the dedusting system 20 are arranged.

In the case of the inert operation of the shredding system a further bypass 23 is arranged after the fan of the dedusting system 20, via which on the one hand the storage silo 16 and the shredding device 13 are ventilated via pipes, for safety reasons are on the sifter 1o, the separator 14 and on the dedusting system 20 bursting disks 24 are provided If it becomes necessary to shut down the shredding system from production, it is possible to remove the coal almost completely from the system, so that a Autoignition or deflagration becomes impossible. The shredding system has a low specific energy requirement due to the choice of machines used onO - blank page -

Claims (1)

Claims 1 method for crushing hard coal and fiber He free brown coal characterized in that the raw coal is crushed in two stages is that the coal dust conveyance via a classifier and a separator of the means a circulated gas stream takes place after the first comminution stage resulting coarse grain is given up in the second crushing stage that the regulation the feed quantity into the shredding system is carried out by the filling quantity in the storage silo 2; The method of claim 1, characterized in that for the second Shredding stage, the first shredding stage is also used by adding the own coarse grain is supplied again 3o The method according to claim 1 characterized that a second crushing stage is used for crushing the coarse grain 4. Device for performing the method according to claim 1, characterized in that that the shredding device 8 is preceded by a task device 1,2,3,4 is that the crusher moved in one of a fan and through this crushing device 8, a classifier lo and a separator 14 guided gas cycle is located, and the separator 14 is followed by a storage silo 16 which has control organs connected to the feed device, 5. device according to claim 4, characterized in that between the gas line 6 and the classifier io a connecting line 11 returning the coarse grain is providedb 6th device according to claim 4, characterized in that between the sifter lo and the riser pipe 9, after the comminution device 8, a further comminution device 13 70 Device according to Claim 4, characterized in that the connecting line 11 a comminution device 8 or a comminution device 13 optionally charging changeover flap 12 has 8. Device according to claim 4 characterized thereby, that the bearing lo 16 is a dosing device 1,2,3,4 in terms of quantity controlling through-dose storage 17 has 90 device according to claim 4, characterized in that in the area the feeding device 3, a magnetic separator 4 is arranged