DE1526174B2

DE1526174B2 -

Info

Publication number: DE1526174B2
Application number: DE19651526174
Authority: DE
Priority date: 1965-11-06
Filing date: 1965-11-06
Publication date: 1970-08-06
Also published as: DE1526174A1

Description

1 21 2

Die Erfindung betrifft ein Verfahren zur Herstel- einen geringeren Aufwand erfordert und sich gleichlung einer brennfertigen Kohle-Wasser-Suspension, zeitig besser für eine Automatisierung der Steuerung gemäß dem Kraftwerkskohle in einem einzigen und Regelung des Mahlkreislaufes eignet.
Durchgang in Gegenwart eines Wasseranteils von 50 Der Erfindung liegt die Aufgabe zugrunde, eine bis 65 Gewichtsprozent auf eine Feinheit von 100 % 5 brennfertige Kohle-Wasser-Suspension in einem einunter etwa 1,5 mm gemahlen, anschließend eine Teil- zigen Durchgang unter Verzicht auf ein besonderes entwässerung der Suspension auf etwa 35 bis 45 Ge- Aggregat zum Entwässern der Suspension herzustelwichtsprozent durchgeführt und das abgetrennte Was- len.The invention relates to a method for the production which requires less effort and is equal to a ready-to-burn coal-water suspension, better suited for automating the control according to the power plant coal in a single and regulating the grinding cycle.
Passage in the presence of a water content of 50. The invention is based on the object of grinding one to 65 percent by weight to a fineness of 100% 5 ready-to-burn coal-water suspension in one under about 1.5 mm, then one part pass with waiver a special dewatering of the suspension to about 35 to 45 Ge aggregate for dewatering the suspension is carried out and the separated water.

ser in den Misch- und Mahlprozeß zurückgeführt Diese Aufgabe wird erfindungsgemäß dadurch gewird, ίο löst, daß die Teilentwässerung der Suspension inwater fed back into the mixing and grinding process This task is achieved according to the invention by ίο solves that the partial drainage of the suspension in

Bei Verwendung einer Kohle-Wasser-Suspension dem zum Mahlen und/oder in dem zum FördernWhen using a coal-water suspension for grinding and / or for conveying

als brennfertiger wasserhaltiger Brennstoff zur direk- der Suspension benutzten Aggregat durchgeführtcarried out as a ready-to-burn water-containing fuel for direct suspension

ten Verfeuerung im Kraftwerk werden die Nachteile wird.th incineration in the power plant will be the disadvantages.

der bekannten Κοη1εη5ΐ3Λίεμεη]ΐ^6η in bezug auf Um eine solche brennfertige Kohle-Wasser-Susdie Verteilung des Brennstoffes vermieden, da eine 15 pension auf einfache Weise herzustellen, ist bei der Kohle-Wasser-Suspension durch ihre mehr oder weni- Vorrichtung zur Durchführung des Verfahrens geger flüssige Beschaffenheit in einfacher Weise die maß der Erfindung die zum Mahlen benutzte Rohrgleichmäßige Beschickung der einzelnen Brenner so- mühle unmittelbar mit einer Entwässerungskammer wie die Dosierung und Überwachung der Brennstoff- verbunden, deren Wände aus einem wasserdurchzuteilung gewährleistet. Außerdem ist es mit Hilfe 20 lässigen Material bestehen. Mit dieser Rohrmühle einer brennfertigen Kohle-Wasser-Suspension mög- wird das Mahlen der Kraftwerkskohle in der Weise lieh, vorhandene Feuerungssysteme, wie beispiels- durchgeführt, daß während der Rotation der Entweise Schmelzkammerkessel oder trocken entaschte Wässerungskammer jeweils der untere Bereich des Kessel, noch nachträglich ohne großen Aufwand auf Filtermaterials einem Unterdruck ausgesetzt und im eine Pipeline-Versorgung umzustellen. 25 oberen Bereich des Filtermaterials ein Überdruckthe well-known Κοη1εη5ΐ3Λίεμεη] ΐ ^ 6η in relation to such a ready-to-burn coal-water susdie Avoided distribution of the fuel, as a 15 pension in a simple way to produce, is with the Coal-water suspension through their more or less device for carrying out the method Geger liquid nature in a simple manner the measure of the invention the pipe used for grinding uniform charging of the individual burner base directly with a dewatering chamber such as the dosing and monitoring of the fuel connected, whose walls consist of a water distribution guaranteed. Besides, it is made with the help of 20 casual material. With this tube mill A ready-to-burn coal-water suspension is able to grind the steam coal in this way borrowed, existing firing systems, such as that carried out during the rotation of the Entweis Melting chamber boiler or dry ash removal chamber in each case the lower area of the Boiler, subsequently exposed to a negative pressure on the filter material without great effort and im to convert a pipeline supply. 25 upper area of the filter material an overpressure

Es ist bekannt, zur Erfüllung dieser Erfordernisse eingestellt wird.It is known that recruitment is made to meet these requirements.

Kraftwerkskohle in einem einzigen Durchgang in Nach einer anderen Ausbildung der erfindungs-Steam coal in a single pass in According to another embodiment of the invention

Gegenwart von etwa 35 Gewichtsprozent Wasser zu gemäßen Vorrichtung besteht bei der zum FördernThe presence of about 35 percent by weight of water in the device according to the present invention is used for conveying

mahlen. Als geeignete Mahlaggregate für die Zer- benutzten Pumpe, vorzugsweise einer Schrauben-grind. As a suitable grinding unit for the used pump, preferably a screw

kleinerung der Kraftwerkskohle in Wasser sind bis- 30 pumpe oder einer Schrägscheibenpumpe, der StatorReduction of the steam coal in water are up to 30 pumps or a swash plate pump, the stator

her Rohrmühlen mit Kugel- und/oder Stabfüllung aus einem wasserdurchlässigen Material, wobei imforth tube mills with ball and / or rod filling made of a water-permeable material, with im

oder Kugelmühlen bekanntgeworden. Falle der Schraubenpumpe der vom Stator und Rotoror ball mills became known. Case of the screw pump that of the stator and rotor

Es ist weiter bekannt, daß die Mahlleistung der gebildete Förderraum entsprechend dem entzogenen Mühlen bei gleicher Endfeinheit des gemahlenen Wasservolumen kontinuierlich abnimmt.
Gutes außer vom Körnungsaufbau des Ausgangs- 35 Die Beschickung der Mahlaggregate mit Kohle materials von dessen Mineralgehalt und der Mineral- und Wasser kann jeweils über eine Misch- und Förzusammensetzung, vorwiegend jedoch von der Höhe derschnecke erfolgen, die über eine Dosierbandwaage des Wasseranteils während des Mahlprozesses ab- mit Rohfeinkohle und über eine Rohrleitung mit hängt. Zur Steigerung der Mahlleistung der Mühlen Wasser versorgt wird. Die Misch- und Förderschnecke ist es deshalb vorteilhaft, wenn bei einem möglichst 40 bewirkt eine innige Durchmischung der Kraftwerkshohen Wasseranteil bis zu 75 Gewichtsprozent die kohle mit dem Wasser und benetzt dabei die Kohle, Naßmahlung der Kraftwerkskohle durchgeführt wird. die von Natur aus hydrophob ist.
Eine Kohle-Wasser-Suspension mit einem Wasser- Die Abtrennung des Wassers bei der Herstellung anteil über 45 Gewichtsprozent ist jedoch für die der brennfertigen Kohle-Wasser-Suspension ist also direkte Verbrennung im Kraftwerk nicht geeignet, 45 beim erfindungsgemäßen Verfahren unmittelbar mit da die Wärmeverluste zu groß wären. der Naßmahlung gekoppelt, oder sie erfolgt mittelsIt is also known that the grinding capacity of the conveying space formed decreases continuously in accordance with the removed mills with the same final fineness of the ground water volume.
Good except for the grain structure of the starting 35 The charging of the grinding aggregates with coal material of its mineral content and the mineral and water can be done via a mixing and conveying composition, but mainly from the height of the screw, which is controlled via a weighfeeder of the water content during the grinding process off with raw fine coal and via a pipeline with it. To increase the grinding capacity of the mills water is supplied. The mixing and conveying screw is therefore advantageous if, if possible, an intimate mixing of the power plant high water content up to 75 percent by weight of the coal with the water and wetting the coal, wet grinding of the power station coal is carried out. which is inherently hydrophobic.
A coal-water suspension with a water The separation of the water during the production share over 45 percent by weight is, however, for the ready-to-burn coal-water suspension so direct combustion in the power station is not suitable, 45 in the process according to the invention directly because the heat losses would be too big. coupled to wet grinding, or it takes place by means of

Gemäß einer bekannten Weiterbildung dieses Ver- eines nachgeschalteten Förderaggregates, das voll-According to a known development of this connection of a downstream conveyor unit, which is fully

fahrens wird deshalb die Kohle-Wasser-Suspension automatisch gesteuert werden kann. Diese zweitedriving is therefore the coal-water suspension can be controlled automatically. This second

vor dem Verbrennen bis auf einen Wassergehalt von Möglichkeit ist insofern besonders vorteilhaft, alsprior to incineration down to a water content of possibility is particularly advantageous in so far as

10 % entwässert und das abgezogene Wasser in den 50 neben der teilweisen Entwässerung diese Aggregate10% dehydrated and the withdrawn water in the 50 in addition to the partial dehydration of these units

Prozeß zurückgeführt. Die Entwässerung erfolgt hier- gleichzeitig einen gewissen Förderdruck aufbringen,Process returned. The drainage takes place here - at the same time apply a certain delivery pressure,

bei mit einer Zentrifuge. Es ist demnach zur Her- Außerdem sind sie einfach im Aufbau und preis-at with a centrifuge. They are therefore easy to assemble and inexpensive.

stellung der brennfertigen Kohle-Wasser-Suspension günstig.position of the ready-to-burn coal-water suspension favorable.

noch ein weiteres Aggregat erforderlich, das gewartet Durch die Rückführung des entzogenen WassersAnother unit is required that is serviced by recirculating the withdrawn water

und in Betrieb gehalten werden muß. 55 zur Herstellung neuer Kohle-Wasser-Suspension ent-and must be kept in operation. 55 for the production of new coal-water suspension

Es ist femer bekannt, daß man die Mahlleistung fällt die sonst erforderliche umständliche Reinigung eines Naßmahlaggregates steigern kann, wenn der des Wassers von Feststoffteilchen.
Mahlvorgang nicht auf einen einzigen Durchgang be- Bei der Durchführung des erfindungsgemäßen Verschränkt wird, sondern das Überkorn auf der Mühle fahrens wird zweckmäßigerweise durch in den Zunachgeschalteten Klassiersieben abgetrennt und wie- 60 lauf und in den Ablauf des kombinierten Mahlder in die Mühle zurückgeführt wird. Bei einem sol- und Entwässerungsaggregates geschaltete induktive chen Kreislauf sind jedoch die Klassiersiebe einem Durchflußmeßgeräte die jeweilige Kohle-Wassererheblichen Verschleiß unterworfen, wodurch eine Suspensionsmenge gemessen und mittels der erhalvollständige Rückführung des Überkorns nicht immer tenen Differenz der Werte über ein Regelventil die gewährleistet ist. Es besteht deshalb die Gefahr, daß 65 Höhe des Vakuums in der Entwässerungseinrichtung die Suspensionsbrenner während des Betriebes in- oder die Fördermenge der brennfertigen Kohlefolge von Verstopfungen ausfallen. Es ist daher einem Wasser-Suspension gesteuert,
einzigen Durchgang der Vorzug zu geben, da dieser An Hand der schematischen Darstellungen werdenIt is also known that the grinding power, which is otherwise necessary, can increase the cumbersome cleaning of a wet grinding unit when solids are removed from the water.
The grinding process is not carried out in a single pass, but rather the oversize grain is expediently separated by the subsequent sizing sieves and fed back into the mill. With a sol and dewatering unit switched inductive circuit, however, the classifying sieves of a flow meter, the respective coal-water are subjected to considerable wear, whereby a suspension amount is measured and, by means of the complete return of the oversized grain, the difference in the values is not always guaranteed via a control valve. There is therefore a risk that the suspension burner will fail during operation or that the delivery rate of the coal sequence ready to burn will fail due to blockages. It is therefore controlled by a water suspension,
preference should be given to single pass, as this will be based on the schematic representations

Claims

3 43 4

further advantages and features of the invention in more detail A b b. 3 shows the drainage in connection with

explained: a tube mill, which is followed by a screw pump

A b b. 1 represents the circuit diagram for the loading is switched. The emerging from the tube mill 1

the grinding units with coal and water. The suspension with a water content of example

Weighing belt feeder 2 pulls the raw coal out of the 5 wise 60 percent by weight of water

Storage bunker 1 and conveys it further into the intermediate bunker 2 in the downstream screw

Mixing and conveyor screw 3, which pump the grinding unit 3. The stator of the screw pump 3 consists

charged via line 5. About the dosing belt made of a water-permeable material 4, for. B. off

balance 2, a moisture meter 4 is attached, ceramic filter material. That escapes through the filter

the water, which continues the water content of the raw coal, is circulated coaxially in a pump

lich measures. To achieve a temporally uniform giving cylindrical jacket 10 collected and

Grain build-up in the coal-water suspension via line 5, which is provided with a valve 6,

it is necessary to feed the grinding unit with a conical mixing screw. That of the stator and rotor

constant amount of solids and the pumping space formed for the suspension increases towards the pump outlet

to operate the required water content. Hence, 15 will decrease continuously as it does

the control of the weighfeeder 2 through which corresponds to the withdrawn water volume. At one

Moisture meter 4 carried out so that the run and outlet of the screw pump 3 is located

Weight fraction of anhydrous coal of the dosing an inductive flow meter 7 and 8, the

belt scales conveyed mixture of coal and water - due to their differential circuit, that of the suspension

ser is always kept constant. 20 determine the amount of water withdrawn and the

The amount of water missing in wet grinding for the desired setpoint of dewatering via the control-coal-water ratio, for example 60 weight valve 9, which is in the pressure line of the pump, percent water, is controlled by means of, with the degree of dewatering from the conveyor Moisture meter 4 and the metering tape pressure of the pump is dependent.
balance 2 taking into account the information already given in 25 A b b. 4 shows the drainage determined by means of two quantities of water contained in the raw fine coal. swash plate pumps connected one behind the other, which on the basis of this measurement, the missing water is used to grind and dewater the amount of coal and water via a control valve 6 through the line 7 suspension. Supplied in the swash plate pump 1. The control valve 6 is the coal-water suspension with, for example, a flow meter 8, which in turn is ground by 30-60 weight percent water and fed into the weighfeeder 2 and the moisture measuring swashplate pump 2. The stator device 4 receives the setpoint. the swash plate pump 2 is here with a FiI-

The A b b. 2 shows a tube mill 1, which is provided by termateriallining 4, for example, no drainage chamber 2 is supplemented, its ramikfilter, slotted sieve, etc. Suitable filter materials are swash plate pump surrounding jacket 10 total. B. wire screens, ceramic filters, slotted screens, fabric melt and via line 5, which is provided with a valve 6 filter, etc. between the filter material and drainage, passed to the mixing screw,
At the inlet and outlet of the swash plate collecting ducts, the pump 2 withdrawn from the suspension is located, for example, with inductive water through holes in the jacket to the outside, flow meters 7 and 8, which, due to their difference, lead to the outside. To support the drainage, the circuit, the amount of water withdrawn from the suspension, collecting channels are connected to a vacuum, whereby the setpoint value of the drainage can be determined and the vacuum through the line 5 can only be found in the flow through the control valve 9, which is in the lower pressure half of the drainage chamber jacket 45 the pump cherishes, control, with the setting, while in the upper half the degree of underwatering is dependent on the delivery pressure of the pump through the supply of compressed air through line 6.

converted into overpressure and thus the filter claims:

clothing is blown free. 1. Process for the production of a ready-to-burn

The dehydration of the coal-water suspension 50 in accordance with the coal-water suspension fully automatically controlled, for example charcoal in a single pass in going from 60 weight percent water in the mill presence of a water content of 50 to 65 for example 40 percent by weight of water by percent by weight to a fineness of 100%> the drainage chamber. For this purpose, it is ground into the under about 1.5 mm, then a Tube mill 1 entering coal-water mixture vo- 55 partial dewatering of the suspension to about 35 to luminally carried out by the inductive flow meter 45 percent by weight and the output device 7 detected. At the outlet of the mill 1 there is separated water in the mixing and grinding process also an inductive flow meter 8, which is fed back, thereby characterized partly drained net already in the drainage chamber2 that the partial drainage of the suspension in Determined coal-water suspension amount. The 60 for grinding and / or for conveying The vacuum influencing drainage is carried out by the aggregate used for the suspension two inductive throughputs connected in difference.

flowmeters 7 and 8 by supplying air 2. Device for carrying out the method

controlled by a control valve 9. rens according to claim 1, characterized in that

The separated water is passed through the line 10 to the tube mill used for grinding returned to the mixing screw while earning indirectly with a drainage chamber Line 11 is the ready-to-burn coal-water susbonds, the walls of which are made of a water-through-board leaves the unit. made of casual material.

3. Device for performing the method according to claim 1, characterized in that that with the pump used for conveying, preferably a screw pump or one Swash plate pump, the stator consists of a water-permeable material, with im Case of the screw pump, the delivery space formed by the stator and rotor according to the withdrawn water volume decreases continuously.

For this purpose 2 sheets of drawings