EP3991858B1 - Operating method for a separator and separator for classification - Google Patents

Description

The present invention relates to an operating method for a classifier and a classifier for classification.

From the DE 102006048864 A1 is an operating method for an air classifier and a corresponding air classifier, each integrated into a jet mill to produce the finest particles. This jet mill air classifier contains a classifying wheel and a classifying wheel shaft as well as a classifier housing. A sifter gap is defined between the sifter wheel and the sifter housing and a shaft bushing is formed between the sifter wheel shaft and the sifter housing. In this wind classifier it is provided that the classifier gap and/or shaft bushing is flushed with compressed gases with low energy content, although the grinding nozzles of the jet mill themselves are charged with high-energy superheated steam. What is special about this design is the combination that grinding nozzles are charged with high-energy superheated steam, i.e. a high-energy medium, while low-energy media are used in the classifier.

From the EP2696981 B1 an operating method for a jet mill system and a jet mill system each with a classifier is known, which contains a classifier shaft and for this a bearing housing and a classifying wheel, superheated steam being used as the operating medium of the jet mill system and the supply of seals between the classifier shaft and its bearing housing as well between the classifying wheel and a fines outlet housing of the jet mill system with the superheated steam.

The EP2959975A1 discloses a method for producing the finest particles by means of a jet mill, the operating medium being a fluid, in particular water vapor, which has a higher speed of sound than air (343 m/s), and also discloses a jet mill for producing the finest particles, wherein a source for an operating medium, in particular water vapor, which has a higher speed of sound than air (343 m/s).

The known processes and classifiers generally lead to good results. The aim of the present invention is to improve the operating method for a sifter and a sifter in such a way that higher fineness can be achieved in the ground product output, in particular compared to sifting with air or inert gases.

This goal is achieved with an operating method for a classifier for the classification of ground material in particular, with superheated water vapor being supplied to the classifier as classifying gas, and with the temperature of the superheated water vapor being chosen as classifying gas so low that there is no condensation of the overheated water vapor comes in the sifter.

Furthermore, the aforementioned goal is achieved with a sifter for classifying, in particular, ground material, the sifter containing a sifting gas supply with a water feed for generating superheated water vapor as sifting gas, and adjusting or regulating devices for the temperature of the superheated water vapor as sifting gas being provided and designed in this way are that the temperature of the superheated water vapor as classifying gas is set so low that there is no condensation of the superheated water vapor in the classifier.

wobei

• dt_Argon = Trennkorndurchmesser Argon (Verwendung als Sichtgas)
• dt_Luft = Trennkorndurchmesser Luft (Verwendung als Sichtgas)

The inventors have recognized that the separation result when sifting with a dynamic sifting wheel depends, among other things, on the process gas used, ie sifting gas. By selecting the sifting gas, the separating cut can be made between Coarse material, which is, for example, fed to further grinding, and fine material, which is output as the desired output product from the classifier as the end product or for further processing, are influenced. For example, when using argon, the separation limit shifts roughly by 18% in relation to air with otherwise unchanged process parameters: $${\mathrm{German}}_{\mathrm{argon}}=1.18{\mathrm{German}}_{\mathrm{Air}}.$$

where

• dt _Argon = separation grain diameter Argon (used as a screening gas)
• dt _air = separation grain diameter air (use as a screening gas)

wobei
dt_Dampf = Trennkorndurchmesser Wasserdampf (Verwendung als Sichtgas)In other words, just by using argon instead of air as the screening gas, the output product will be more coarse. The inventors have also discovered that the separation limit shifts to a finer extent when using superheated steam as a screening gas in relation to air: $${\mathrm{German}}_{\mathrm{steam}}=0.8{\mathrm{German}}_{\mathrm{Air}}.$$

where
dt _steam = separation grain diameter water vapor (used as a screening gas)

Practical tests have shown that when sifting with superheated water vapor as the sifting gas, significantly higher fineness is achieved than the aforementioned theoretical factor of 0.8 suggests compared to air.

It is assumed that the improved separation limit or selectivity when using superheated steam instead of air as a classifying gas results in a kind of additiveization of the product during the classifying process, which further advantageously results in a significantly higher yield.

wobei

• dt_h = Trennkorndurchmesser in Abhängigkeit der Temperatur des Sichtgases
• T_h = Hohe Temperatur des Sichtgases
• T_u = Niedrigere Temperatur des Sichtgases

Furthermore, the inventors have recognized that when sifting with superheated steam, the temperature of this sifting gas is relevant to the result. They found that the classifier separates more coarsely at higher classifying gas temperatures and that this is another criterion that is due to the fact that overheated water vapor When the saturated steam temperature falls below the saturated steam temperature, the sifting gas temperature must be set so that there is no condensation of the steam in the process. The technical lesson from this is that a minimum of the necessary visible gas temperature, ie the superheated steam or superheated water vapor, should be aimed for: $${\mathrm{German}}_{\mathrm{H}}={\left({\mathrm{T}}_{\mathrm{H}}/{\mathrm{T}}_{\mathrm{u}}\right)}^{0.25}$$

where

• dt _h = separation grain diameter depending on the temperature of the classifying gas
• T _h = High temperature of the screening gas
• T _u = Lower temperature of the sighting gas

• T_u = ca. 383 K (ca. 10 K über Sattdampftemperatur)
• T_h = ca. 723 K

Limits of temperature for superheated water vapor:

• T _u = approx. 383 K (approx. 10 K above saturated steam temperature)
• T _h = approx. 723 K

• Der absolute Druck am Sichtereintritt in bar(a)
• Die Wärmekapazität des Sichtgutes in J/kgK
• Die Temperatur des Sichtgutes in K
• Die Aufgabemenge des Produktes in kg/h
• Der Energieeintrag des Sichtgas/Prozessgasverdichters
• Der Energieeintrag durch den Sichter
• Die Masse des eingespritzten Wassers zur Dampferzeugung und Kühlung des Prozessgases in kg/h
• Wärmestromverluste durch Abstrahlung an die Umgebung in W

Further parameters that are noteworthy within the scope of the invention and are advantageously to be included in particular in the selection and adjustment of the temperature of the classifying gas both in terms of process and apparatus by means of appropriate sensor and determination devices and individually or in any combination are:

• The absolute pressure at the classifier inlet in bar(a)
• The heat capacity of the visible material in J/kgK
• The temperature of the visible material in K
• The feed quantity of the product in kg/h
• The energy input of the classifying gas/process gas compressor
• The energy input through the classifier
• The mass of the injected water to generate steam and cool the process gas in kg/h
• Heat flow losses due to radiation to the environment in W

Advantageously, in the operating method for a classifier for the classification of ground material in particular, it can also be provided that the superheated water vapor in is used in a cycle gas process. As a preferred and advantageous further development, it can be provided that the necessary superheated steam is generated by supplying liquid water.

A further preferred embodiment of the operating method for a classifier for classifying regrind in particular is that superheated water vapor is also supplied to the classifier to flush a classifier gap of the classifier and/or to protect the bearings of the classifier from product contamination.

Advantageously, the operating method for a classifier for the classification of ground material in particular can be developed in such a way that, if necessary, a pressure difference is generated in the circuit using a classifying gas blower or classifying gas compressor to promote the flow of the classifying gas. It can also preferably be provided that the pressure difference is set or regulated depending on system resistances, and in particular it can be provided that the temperature of the superheated steam in connection with the heating and the discharge of the visible material is used for setting or regulating the temperature of the superheated water vapor is used as a classifying gas in the classifier.

A yet further preferred embodiment of the operating method for a classifier for classifying ground material in particular is that the temperature of the superheated water vapor as classifying gas is carried out by adjusting or regulating the amount and/or temperature of liquid water that is introduced into the classifying gas.

The classifier can advantageously be further developed in that a circuit for the superheated steam is included. Alternatively or additionally, it can be provided that flushing devices are included and designed for a classifier gap of the classifier and/or to protect the bearings of the classifier from product contamination in order to supply superheated water vapor to the corresponding points.

Yet another advantageous embodiment of the classifier is that a classifying gas blower or classifying gas compressor to promote the flow of the classifying gas is optionally included in the circuit through a pressure difference. It can preferably also be provided that adjustment or control devices are provided for the sifting gas blower or the sifting gas compressor for adjusting or regulating the pressure difference depending on system resistances, which can be further developed by at least one temperature sensor for the superheated water vapor, which is at the output assigned to the classifier and functionally coupled to the setting or control devices for the temperature of the superheated water vapor as a classifying gas, so that the output of this temperature sensor is used as the input of the setting or control devices for the temperature of the superheated water vapor to be taken into account.

It can also advantageously be provided in the classifier that the water feed is coupled to the setting or control devices for the temperature of the superheated water vapor as a classifying gas and is designed in such a way that the temperature of the superheated water vapor as a classifying gas can be set or controlled by setting or regulating of the amount and/or temperature of liquid water that is introduced into the screening gas.

Further preferred and/or advantageous embodiments of the invention and its individual aspects result from combinations of the dependent claims and from the entire present application documents.

Fig. 1

eine schematische Skizze eines erfindungsgemäßen Prozesses mit einem Sichter ist,

Fig. 2

Prozessparameter eines ersten Rechenbeispiels sind, und

Fig. 3

Prozessparameter eines zweiten Rechenbeispiels sind.

Some exemplary explanations for specific configurations are given below and exemplary embodiments of the invention are explained merely by way of example with reference to the drawing, in which

Fig. 1

is a schematic sketch of a process according to the invention with a classifier,

Fig. 2

Process parameters of a first calculation example are, and

Fig. 3

Process parameters of a second calculation example are.

The invention is explained in more detail using the exemplary embodiments and applications described, i.e. it is not limited to these exemplary embodiments and applications. Process and device features also result analogously from device or process descriptions.

Individual features that are specified and/or shown in connection with a specific exemplary embodiment are not limited to this exemplary embodiment or the combination with the other features of this exemplary embodiment, but can, within the scope of what is technically possible, with any other variants, even if they are included in are not dealt with separately in these documents.

In the Fig. 1 an exemplary embodiment of a classifier 1 is illustrated in a schematic sketch, in which the individual components of the classifier 1 and their connections are only illustrated as examples. The proportions of the in the Fig. 1 The components of the sifter 1 shown do not correspond to reality, but were only chosen in the given manner for understanding and reasons of recognizability.

The underlying method is a method for classifying, ie for classifying, in particular, ground material, in particular but not necessarily from a mill (not shown), such as a jet mill, with superheated steam, preferably but not limited to this, in a circulating gas process, with the classifier 1 in Process flow may be integrated into the mill before a regrind outlet or may be connected downstream as a separate apparatus of the mill, ie its regrind outlet.

The classifier 1 contains a dynamic classifier wheel 2, which is rotatably arranged in a classifier housing 3 about a classifier wheel axis (not shown) and is spaced from the inner wall (not designated) of the classifier housing 3 by a so-called classifier gap (not shown). The classifier wheel 2 is rotatably mounted in at least one bearing (not shown) of the classifier 1 to achieve its rotation.

Below is an exemplary embodiment to be understood as an example to illustrate the structure and operating method of the classifier 1 with further details with reference to Fig. 1 described. This description includes the generation of superheated steam and the cycle gas process, which is only to be understood as one possibility. Superheated steam can also be provided and supplied in other ways and can also be used outside of a cycle gas process. In particular, this means that the separation process with superheated steam can basically be carried out in cycle gas as well as through gas operation. The energy requirement of the cycle gas process is particularly advantageously only approx. 5% of that of operation in through gas. This is due to the fact that when the system is open, the water vapor leaves the system overheated and is irrevocably lost.

The product flow in the classifier 1 is as follows:
Classified material S, which comes, for example, from a mill (not shown) or its grinding chamber (not shown), is fed to the classifier 1 via a classified material feed as a classifier inlet 4. In order to separate the process from the atmosphere, the classified material S is, for example, but not necessarily introduced into the classifier housing 3 in a metered manner via a rotary valve as a feed lock 5. Coarse material G, which needs to be ground further or again or is sorted out because it is still too coarse, leaves the classifier 1 through, for example, a coarse material lock 6.

Fine material F, which meets the desired final specifications, passes through the classifier wheel 2 and is conveyed with classifying gas into a filter 7 and leaves this filter 7 at the end to the atmosphere through, for example, a fine material lock 8. The screening gas is at least largely passed on to a screening gas or generally process gas compressor 9, which is preceded by, for example, a security or police filter 10 for its protection.

Now there is a description of the flow of the classifier or, in relation to the classifier, general process gas stream for the in the Fig. 1 schematically illustrated exemplary embodiment.

The sifting gas compressor, which can be implemented for example by a sifting gas blower 9 and can be referred to as such, generates the necessary pressure difference to convey the process gas and in particular sifting gas in the circuit in the example shown. Here, the classifying/process gas blower or the classifying/process gas compressor 9 is advantageously designed in such a way that all system resistances can be overcome in order to generate a stable process gas flow and in particular classifying gas flow.

1. 1) Sichtgas
2. 2) Spaltgas zur Spülung des Sichterspaltes
3. 3) Lagergas zum Schutz der Lager vor Produktverunreinigungen

The process gas in the form of superheated steam is divided into 3 partial streams:

1. 1) Sight gas
2. 2) Cracking gas for flushing the classifier gap
3. 3) Bearing gas to protect bearings from product contamination

For all 3 partial gas streams, which in total result in the process gas stream, of which only the classifying gas stream is relevant for the aspects according to the invention for producing a higher/better fineness of the fine material F, which is why it is equated with the latter in this description, superheated water vapor is used . It is advantageous and therefore preferably desirable not to introduce any air into the circulating gas process. This would lead to a dilution of the process gas and a shift in the viscosities and densities, which would lead to a rough separation of the classifier.

It is, among other things, advantageous if the bearing (not shown) and also the classifier gap (not shown) of the classifier 1 are also flushed with superheated steam, which is diverted from the classifying gas stream for these purposes.

Other components of the in the Fig. 1 The exemplary embodiment of the classifier 1 shown is a pipeline 11, water injection fittings 12, a control valve 13, a temperature sensor 14, an operating pressure sensor 15, a supply pressure sensor 16, a control valve 17, a water feed 18 and an exhaust steam outlet 19.

wobei

• dt_h = Trennkorndurchmesser in Abhängigkeit der Temperatur des Sichtgases
• T_h = Hohe Temperatur des Sichtgases
• T_u = Niedrigere Temperatur des Sichtgases

Due to the fact that superheated steam condenses when the saturated steam temperature falls below the saturated steam temperature, the classifying gas temperature when using superheated steam must be set so that no condensation of the steam occurs in the process. In other words, the aim here is to achieve a minimum of the necessary viewing gas temperature. $${\mathrm{German}}_{\mathrm{H}}={\left({\mathrm{T}}_{\mathrm{H}}/{\mathrm{T}}_{\mathrm{u}}\right)}^{0.25}$$

where

• dt _h = separation grain diameter depending on the temperature of the classifying gas
• T _h = High temperature of the screening gas
• T _u = Lower temperature of the sighting gas

• T_u = ca. 383 K (ca. 10 K über Sattdampftemperatur)
• T_h = ca. 723 K

Limits of temperature for superheated water vapor:

• T _u = approx. 383 K (approx. 10 K above saturated steam temperature)
• T _h = approx. 723 K

• Der absolute Druck am Sichtereintritt in bar(a)
• Temperatur des Sichtgutes in K
• Die Wärmekapazität des Sichtgutes S in J/kgK
• Die Aufgabemenge des Produktes in kg/h
• Der Energieeintrag des Prozessgasverdichters
• Der Energieeintrag durch den Sicher
• Die Masse des eingespritzten Wassers zur Dampferzeugung und Kühlung des Prozessgases in kg/h
• Wärmestromverluste durch Abstrahlung an die Umgebung in W, können bei ausreichender Isolation und Begleitheizungen vernachlässigt werden (siehe Fig. 1, Bezugszeichen 6, 7, 8)

Further parameters that are noteworthy within the scope of the invention and are advantageously to be included in particular in the selection and adjustment of the temperature of the classifying gas both in terms of process and apparatus by means of appropriate sensor and determination devices and individually or in any combination are:

• The absolute pressure at the classifier inlet in bar(a)
• Temperature of the visible material in K
• The heat capacity of the visible material S in J/kgK
• The feed quantity of the product in kg/h
• The energy input of the process gas compressor
• The energy input through the safe
• The mass of the injected water to generate steam and cool the process gas in kg/h
• Heat flow losses due to radiation to the environment in W can be neglected if there is sufficient insulation and trace heating (see Fig. 1 , reference numbers 6, 7, 8)

Below we will discuss the generation of superheated steam in detail as an example.

Energy flows are supplied and removed in the cycle gas process. If it is permissible to assume an adiabatic system in the gas cycle process, an energy balance can be carried out.

• Produkt (Sichtgut S) Q. = ṁ*cp*T
• Sichter (Antrieb) Q. = Pw (Wellenleistung)
• Prozessgasgebläse Q. = Pw (Wellenleistung)
• Wasser flüssig Q. = h*m

Energy flows supplied: Q.to

• Product (visible material S) Q. = ṁ*cp*T
• Classifier (drive) Q = Pw (shaft power)
• Process gas blower Q = Pw (shaft power)
• Water liquid Q. = h*m

• Feingut F Q. = ṁ*cp*T
• Grobgut G Q. = ṁ*cp*T
• Abdampf O. = m*h

Dissipated energy flows: Q.ab

• Fines F Q. = ṁ*cp*T
• Coarse material G Q. = ṁ*cp*T
• Exhaust steam O. = m*h

• dQ. = m H2O * (h abdampf - h H2O flüssig)
• wobei
• Q. = Wärmemenge in Watt
• m = Massenstrom kg/s
• cp = Wärmekapazität in j/kgK
• T = Temperatur in K
• h = Enthalpie in J/kg

Difference in energy flows:

• dQ. = m H2O * (h exhaust vapor - h H2O liquid)
• where
• Q = amount of heat in watts
• m = mass flow kg/s
• cp = heat capacity in j/kgK
• T = temperature in K
• h = enthalpy in J/kg

The difference in energy flows is used to evaporate and superheat the added liquid water.

In the exemplary embodiment shown, it is crucial that the amount of liquid water supplied via the water feed 18 is added in such a way that the resulting water vapor is in superheated form at every point in the system due to the difference in energy flows. The water feed 18 is connected downstream of the classifying or process gas blower in the direction of flow of the classifying and process gas, where the highest temperature level in the system, i.e. the classifier 1 with all its components, is located.

The temperature control in the circulating gas process will now be discussed in more detail in the exemplary embodiment discussed here.

In order to ensure that the water vapor is overheated at every point in the system, i.e. in the classifier 1, the circulating gas temperature is measured at various points in the system.

The temperature after classifier 1 is used as the controlled variable. As expected, the greatest drop in temperature will occur here due to the heating and the discharge of the visible material. This temperature drop can be calculated. Depending on the temperature after the classifier 1, a defined amount of water in the liquid state is supplied to the classifying gas or process gas compressor. The amount of water to be supplied is selected so that before the classifying gas or process gas compressor there is a sufficient temperature difference above saturated steam temperature (approx. dT = 10 to 100 K).

• Der absolute Druck des Prozessgases vor dem Prozessgasverdichter in bar(a)
• Die Wärmekapazität des Sichtgutes S in J/kgK
• Temperatur des Sichtgutes in K
• Die Aufgabemenge des Produktes in kg/h
• Der Energieeintrag des Prozessgasverdichters
• Der Energieeintrag durch den Sicher

To set or regulate the amount of water to be supplied, the following parameters can be taken into account, which is implemented via appropriate sensors (not shown) and setting or control devices 20:

• The absolute pressure of the process gas upstream of the process gas compressor in bar(a)
• The heat capacity of the visible material S in J/kgK
• Temperature of the visible material in K
• The feed quantity of the product in kg/h
• The energy input of the process gas compressor
• The energy input through the safe

The process is cooled by the enthalpy of vaporization of the water and can therefore be kept at a constant temperature level. This creates superheated water vapor. In any case, it is important to avoid falling below the saturated steam temperature, otherwise condensate will form and safe operation of the process will no longer be possible. Since the saturated steam temperature is pressure-dependent, this pressure in the system, i.e. in the classifier 1, is preferably measured continuously and the saturated steam temperature is calculated from this. A comparison with the real temperatures is preferably also carried out continuously.

In order to ensure that there is no loss of heat flow to the environment, the entire system, ie the classifier 1, is preferably insulated in a heat-tight manner. The entry elements, in particular rotary valve as feed lock 5, and discharge elements, in particular coarse material lock 6 and fine material lock 8, as well as filter 7 and security or police filter 10 are advantageously equipped with additional trace heating.

For the exemplary embodiment in question, some details for the pressure control in the circulating gas process will now be given.

The amount of water supplied, which is evaporated and overheated due to the energy differences between input and output in the circulating gas process, must leave the circuit again, otherwise the pressure in the system would increase. For this purpose, an operating pressure sensor 15 is installed in front of the classifier housing 3, which regulates the system pressure via the control valve 13 or a corresponding control flap. Depending on the amount of water supplied and the amount of gas removed, any desired or required system pressure can be set. This amount of water, which turns into superheated water vapor, removes the air in the system and the air supplied by the product during operation from the process.

A further pressure control via the supply pressure sensor 16 and the control valve 17 is provided upstream of the sighting gas or process gas compressor 9. This can be used to increase the overall system resistance if necessary. The result of this is that the energy input through the classifying/process gas blower or the classifying/process gas compressor 9 is increased. This may be necessary at very high throughputs and the associated greater cooling of the process gas during the classifying process due to the removal of coarse material G and fine material F.

Examples are in the Fig. 2 and 3 System characteristics / process parameters / operating parameters shown. For this purpose, various calculations were carried out to show to what extent the process parameters and the amounts of water to be supplied change depending on the operating parameters. The corresponding calculations have been carried out for one type of classifier as an example. Scaling up to other sizes is possible.

For a first calculation example, the operating parameters are shown in the following tables:

Water injection kg/h 13.42

Pressure after blower mbar(g) 0 Gas temperature after classifier °C 120 Mass flow product kg/h 75 Heat capacity product J/kgK 1000 Product inlet temperature °C 20 Product outlet temperature °C 60 Shaft power blower kW 10.9 Shaft power classifier kW 1

Calculation of the mass flow of the steam

Mass flow classifier 250 kg/h gap 75 kg/h additive 0 kg/h camp 10 kg/h Total 335 kg/h

Pressure drop across the system components

Classifier 300 mbar Product filter 15 mbar Security filter 10 mbar Total pressure drop across the system components 325 mbar

Pressure drop in pipes

S class and filters 1 mbar Line between filter and safety filter 1 mbar Line between safety filter and fan 1 mbar Line between blower and S_Class 2 mbar Total pressure drop in lines 5 mbar

Druck [mbar(g)] -2 -202 -203 -318 -319 329 330 0 0

gesamtes Dampfvolumen [m3/h)] 607 870 872 891 892 905 907 697 608

Temperatur [°C] 119 120 120 120 120 120 120 178 119

Sattdampftemperatur [°C] 99,9 91,4 91,4 90,9 90,8 90,5 90,5 100,0 100,0

Wasser-zufuhr [kg/h] 0 0 0 0 0 0 0 0 13,42 The values for measuring points A to I in the Fig. 2 For the sake of clarity, they are shown in the table below: A b C D E F G H I before classifier according to classifier before product filter by product filter before safety filter by security filter in front of fan after blower after water supply

Pressure [mbar(g)] -2 -202 -203 -318 -319 329 330 0 0

total steam volume [m3/h)] 607 870 872 891 892 905 907 697 608

Temperature [°C] 119 120 120 120 120 120 120 178 119

Saturated steam temperature [°C] 99.9 91.4 91.4 90.9 90.8 90.5 90.5 100.0 100.0

Water supply [kg/h] 0 0 0 0 0 0 0 0 13.42

For a second calculation example, the operating parameters (change in the feed rate of the classifier 1 and reduction in the circulating amount of steam and the system pressure after the process gas compressor 9) are shown in the tables below:

Water injection kg/h 8.29

Pressure after blower mbar(g) 60 Gas temperature after classifier °C 120 Mass flow product kg/h 250 Heat capacity product J/kgK 1000 Product inlet temperature °C 20 Product outlet temperature °C 60 Shaft power blower kW 8.0 Shaft power classifier kW 1

Calculation of the mass flow of the steam

Mass flow classifier 150 kg/h gap 75 kg/h additive 0 kg/h camp 10 kg/h Total 235 kg/h

Pressure drop across the system components

Classifier 300 mbar Product filter 15 mbar Security filter 10 mbar Total pressure drop across the system components 325 mbar

Pressure drop in pipes

S class and filters 1 mbar Line between filter and safety filter 1 mbar Line between safety filter and fan 1 mbar Line between blower and S class 2 mbar Total pressure drop in lines 5 mbar

Druck [mbar(g)] 58 -242 -243 -258 -259 -269 -270 60 60

gesamtes Dampfvolumen [m3/h)] 417 562 563 574 575 683 584 470 417

Temperatur [°C] 134 120 120 120 120 120 120 186 134

Sattdampftemperatur [°C] 101,4 93,3 93,3 92,8 92,8 92,5 92,4 101,5 101,5

Wasser-zufuhr [kg/h] 0 0 0 0 0 0 0 0 8,29 In the Fig. 3 the process parameters are shown. The values for measuring points A to I in the Fig. 3 For the sake of clarity, they are shown in the table below: A b C D E F G H I before classifier according to classifier before product filter by product filter before safety filter by security filter in front of fan after blower after water supply

Pressure [mbar(g)] 58 -242 -243 -258 -259 -269 -270 60 60

total steam volume [m3/h)] 417 562 563 574 575 683 584 470 417

Temperature [°C] 134 120 120 120 120 120 120 186 134

Saturated steam temperature [°C] 101.4 93.3 93.3 92.8 92.8 92.5 92.4 101.5 101.5

Water supply [kg/h] 0 0 0 0 0 0 0 0 8.29

• Wahl des Prozessgases - überhitzter Wasserdampf für feinere Trennungen und höhere Ausbeuten
• Spülung der Lager mit dem Prozessgas (überhitzter Wasserdampf) um eine Verdünnung des Prozessgases zu verhindern
• Zugabe von flüssigem H₂0 zur Temperaturreglung des Prozessgases
• Zugabe von flüssigem H₂0 zu Erzeugung des Prozessgases (überhitzter Wasserdampf)
• Regelung der Wasserzugabe in Abhängigkeit der Sattdampftemperatur
• Regelung der Wasserzugabe in Abhängigkeit der zugeführten und abgeführten Wärmemengenströme
• Einstellung der Sattdampftemperatur durch variable Druckregelung in der Anlage
• Zuführung der Wasserzugabe nach dem Sichtgas/Prozessgasgebläse möglichst effektive Verdampfung und Überhitzung zu erreichen
• Veränderung der Wellenleistung des Sichtgas/Prozessgasgebläses und damit variable Einstellung des Energieeintrages in den Prozess über druckabhängige Regelung vor dem Sichtgas/ Prozessgasverdichter
• Adiabates System: Ausgleich von Wärmeverlusten durch Begleitheizungen an den Filtern, Ein- und Austragsorganen und Isolation der Rohrleitungen
• Fahrweise des Prozesses im Kreisgassystem
• Energiebedarf bei der Fahrweise im Kreisgassystem liegt bei ca. 5% von der bei der offenen Fahrweise
• Fahrweise im offenen Prozess ist möglich

For the operating method for the classifier 1 for the classification of regrind in particular, as well as this classifier 1 in terms of apparatus, the following features of the process must be mentioned or highlighted as individual or combinable effects and design options:

• Choice of process gas - superheated steam for finer separations and higher yields
• Flushing the bearings with the process gas (superheated steam) to prevent dilution of the process gas
• Addition of liquid H ₂ 0 to control the temperature of the process gas
• Addition of liquid H ₂ 0 to generate the process gas (superheated steam)
• Control of water addition depending on the saturated steam temperature
• Control of the addition of water depending on the heat flows supplied and removed
• Setting the saturated steam temperature through variable pressure control in the system
• Supplying the water after the classifying gas/process gas blower to achieve the most effective evaporation and superheating possible
• Changing the shaft power of the sifting gas/process gas blower and thus variable adjustment of the energy input into the process via pressure-dependent control in front of the sifting gas/process gas compressor
• Adiabatic system: Compensation of heat losses through heat tracing on the filters, inlet and outlet elements and insulation of the pipes
• How the process operates in the circulating gas system
• The energy requirement when operating in the circular gas system is approx. 5% of that when operating in an open manner
• Driving in an open process is possible

A further pressure control via the supply pressure sensor 16 and the control valve 17 can be provided upstream of the sighting or process gas compressor 9. This can be used to increase the overall system resistance if necessary. The result of this is that the energy input through the classifying/process gas blower or the classifying/process gas compressor 9 is increased. This can enable advantageous compensation at very high throughputs and the associated greater cooling of the process gas during the classifying process by removing coarse material G and fine material F.

The invention is shown only as an example based on the exemplary embodiment and preferred embodiments in the description and is not limited thereto, but includes all variations, modifications, substitutions and combinations that the person skilled in the art would consider in the present documents, particularly within the scope of the claims and the general representations in the introduction to these Description and the description of the exemplary embodiments can be found and combined with his professional knowledge and the state of the art.

Reference symbol list

1

Sifter

2

sifter wheel

3

Classifier housing

4

Classified material feed, classifier entry

5

feed lock

6

Coarse material lock

7

filter

8th

Fine sluice

9

Sifting gas blower or separating gas compressor or process gas blower or process gas compressor

10

Security or police filter

11

pipeline

12

Water injection fittings

13

control valve

14

Temperature sensor, temperature sensor

15

Operating pressure sensor

16

Supply pressure sensor

17

control valve

18

Water feed

19

Exhaust steam outlet

20

Setting or control devices

F

Fine goods

G

Coarse goods

S

Visible good

Claims (15)

1. An operating method for a separator (1) for classifying,
   characterized in
   that superheated steam is supplied to the separator (1) as separating gas, and that the temperature of the superheated steam as separating gas is selected to be so low that in particular no condensation of the superheated steam occurs in the separator (1).
2. The operating method for a separator (1) for classifying according to claim 1,
   characterized in
   that the temperature of the superheated steam as separating gas is adjusted or regulated as a function of

   - the absolute pressure at a separator inlet (4) in bar (a),

   - the temperature of the separating material,

   - the thermal capacity of a separating material (S) in J / kgK,

   - a feed quantity of the product in kg/h,

   - the energy input of an included separating gas/process gas compressor (9),

   - the energy input by means of the separator (1),

   - the mass of the injected water for generating steam and cooling the separating gas in kg/h, and/or

   - heat flow losses due to emission to the environment in W.
3. The operating method for a separator (1) for classifying according to claim 1 or 2,
   characterized in
   that the superheated steam is used in a recirculating gas process, wherein the necessary superheated steam is preferably generated by the supply of liquid water.
4. The operating method for a separator (1) for classifying according to one of the preceding claims,
   characterized in
   that superheated steam is supplied to the separator (1) also for flushing a separator gap of the separator (1) and/or for protecting the bearings of the separator (1) against product contaminations.
5. The operating method for a separator (1) for classifying according to one of the preceding claims,
   characterized in
   that a pressure difference is generated by means of a separating gas blower or separating gas compressor (9) for conveying the flow of the separating gas, optionally in the cycle.
6. The operating method for a separator (1) for classifying according to claim 5,
   characterized in
   that the pressure difference is adjusted or regulated as a function of plant resistances.
7. The operating method for a separator (1) for classifying according to one of the preceding claims,
   characterized in
   that the temperature of the superheated steam is used as separating gas in the separator (1) in connection with the heating and the output of the separating material for the adjustment or regulation of the temperature of the superheated steam.
8. The operating method for a separator (1) for classifying according to one of the preceding claims,
   characterized in
   that the temperature of the superheated steam as separating gas takes place by means of adjustment or regulation of quantity and/or temperature of liquid water, which is introduced into the separating gas.
9. A separator (1) for classifying,
   characterized in
   that the separator (1) includes a separating gas supply comprising a water infeed (18) for generating superheated steam as separating gas, and that adjusting or regulating means (20) for the temperature of the superheated steam are provided as separating gas and are designed so that the temperature of the superheated steam as separating gas is adjusted to be so low that in particular no condensation of the superheated steam occurs in the separator (1).
10. The separator (1) according to claim 9,
    characterized in
    that a cycle for the superheated steam is present.
11. The separator (1) according to claim 9 or 10,
    characterized in
    that flushing means are present for a separator gap of the separator (1) and/or to protect the bearings of the separator (1) against product contaminations and are designed to supply superheated steam to the corresponding spots.
12. The separator according to one of claims 9 to 11, characterized in
    that a separating gas blower or separating gas compressor (9) for conveying the flow of the separating gas is optionally present in the cycle by means of a pressure difference.
13. The separator according to claim 12,
    characterized in
    that adjusting or regulating means (20) are provided for the separating gas blower or the separating gas compressor (9) for adjusting or regulating the pressure difference as a function of plant resistances.
14. The separator according to claim 13,
    characterized in
    that at least one temperature probe (14) for the superheated steam is assigned to the outlet of the separator and is functionally coupled to the adjusting or regulating means (20) for the temperature of the superheated steam as separating gas, so that the output of this temperature probe (14) is used as input, which is to be considered, of the adjusting or regulating means (20) for the temperature of the superheated steam.
15. The separator (1) according to one of claims 9 to 14,
    characterized in
    that the water infeed (18) is coupled to the adjusting or regulating means (20) for the temperature of the superheated steam as separating gas and is designed so that the adjustment or regulation of the temperature of the superheated steam as separating gas is realized via this by means of adjustment or regulation of quantity and/or temperature of liquid water, which is introduced into the separating gas.

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