EP4506573A1 - Integrated bypass cooling for turbo compressors using two or more process stages - Google Patents

Abstract

at least one supply line (2) for a gas flow containing at least one gaseous compound to a compressor unit (4), as well as at least one discharge line (3) of the compressed gas flow from said compressor unit (4),said compressor unit (4) containing at least a first compressor stage (1) and a final compressor stage (F), wherein the supply line (2) is in fluid communication with the gas inlet of the first compressor stage (1) and the gas outlet of the first compressor stage (1) is in fluid communication with the gas inlet of a last cooling device (WA00F), as well as the gas outlet of the last cooling device (WA00F) is in fluid communication with the gas inlet of the final compressor stage (F),as well as the discharge line (3) is in fluid communication with the gas outlet of the final compressor stage (F),at least one first bypass (6a) which connects the discharge line (3) to the fluid connection which is located between the last cooling device (WA00F) and the compressor stage immediately preceding it, wherein a line located in the first bypass (6a), at least one valve (10) containing a first flow control (5a), the amount of gas guided in the bypass gas flow can be controlled and the flow of the gas flow through the final compressor stage (F) can thereby be regulated,at least one second bypass (6b) provided with a second flow control (5b), which connects the fluid connection located between the last cooling device (WA00F) and the final compressor stage (F) to the feed line (2),and a corresponding method that can be carried out using this device, the pump protection of the compressor unit (4) can be better coordinated with the individual compressor stages and condensation of the returned, compressed gas flow can be avoided. The gas flow finally compressed by the method supplies a compressed, hot gas that can be used for heat integration in process steps that follow the compression.

Description

The invention relates to the compression of process gases, in particular with turbo compressors, and the control of the compressors used by regulating the gas flow before it is introduced into a compressor stage with the aid of bypasses. This regulation is achieved by the compression method according to the invention and by a device with a special bypass circuit.

Compressors play an important supporting role in the industrial production of gases. For example, a compressor takes gas from a gas source for compression and delivers this compressed gas to a gas consumer. When the gas is introduced into the compressor, the pumping effect of the compressor creates suction, which is why the side of the compressor with the gas supply is also called the suction side of the compressor.

In order to be able to use compressors reliably in a process, the compression achieved by the individual compressor stages must be kept within a certain pressure range. In particular, the compressor must be controlled in such a way that it can continuously deliver the gas flow requested by a downstream consumer from the gas source at a specific pressure and at the requested flow rate. The compressor control must be able to respond variably to this requested flow rate.

In addition, especially in turbo compressors, the compressor control is also responsible for protecting the compressor stages. The compressor stages are operated with a surge limit control, which ensures the flow through the compressor stage regardless of the amount of gas provided by the supply line so that the minimum permissible flow (i.e. the surge limit) is never undercut. This phenomenon, known as surge, leads to vibrations in the compressor stage, destroys the turbo compressor and must therefore be avoided.

According to the state of the art, the surge limit control is carried out in such a way that part of the compressed gas is returned to the compressor stage via a bypass. When using several compressor stages one after the other, each compressor stage has its own surge limit. In this case, a Feedback from the last compressor stage is provided before the first compressor stage in order to protect all stages simultaneously.

This state of the art has two disadvantages:
On the one hand, the recirculation cannot be adjusted individually to the individual compressor stages, so that the bypass is larger than necessary.

On the other hand, the part of the gas stream heated by compression from the last compressor stage that is intended for recirculation must be cooled so that it does not enter the first stage hot and lead to an unacceptably high temperature at the outlet. If the returned, compressed gas has to be cooled to a temperature close to its dew point, there is a risk that the dew point will be accidentally exceeded and the resulting droplets will be fed into the first compressor stage with the gas stream and cause erosion damage there.

Therefore, it is an object of the invention that, compared to the prior art, the pump protection can be better adapted to the individual compressor stages using the device.

Another task is to avoid condensation of the returned, compressed gas.

Another task is to provide a compressed, hot gas to be used for heat integration in process steps following compression.

It is also an object of the present invention to provide a method and a device for compressing gases, which has at least two surge limit controls and is capable of providing a gas flow in the required gas quantity on the suction side of the corresponding compressor stages.

During compression, the compressed gas heats up, so that in a multi-stage compression process it is cooled between the compressor stages. This increases the efficiency of compression and prevents the compressor and the gas from heating up beyond permissible temperature limits. Common heat exchanger types are used to cool the gas flow. Usually, a cooling device is provided after each compressor stage to cool the gas flow. This type of cooling is both energy-intensive and expensive to provide and maintain. The necessary cooling devices involve the expenditure of resources, such as materials and costs. The new process and the new device are intended to conserve resources and in particular save energy, e.g. for cooling.

Furthermore, the decommissioning and maintenance of the compression device used should be simplified. When decommissioning, the supply and discharge lines of the compressor unit are closed. The gas in the individual compressor stages has different pressures and now flows within the compressor unit into areas of lower pressure until a uniform pressure prevails in the compressor unit, the settle-out pressure. For maintenance work, the gas must be drained from the compressor unit after the settle-out pressure has been set and, if necessary, then removed from the entire compression device using a purge gas.

It has been found that a modified method and a modified device for compressing gases solves the aforementioned problems if the compression device contains at least two special bypasses in addition to at least two compressor stages.

With the present invention, unintentional condensation of the compressed gas behind the last compressor stage is avoided by the absence of a cooling device between the last compression stage and the branch provided for recirculation for the final compressed gas flow. As a result, the gas returned to the cooling device in front of the suction side of the previous compressor stage no longer causes erosion of this compressor stage by condensate droplets, even without the installation of liquid separators.

By eliminating the need for a cooling device between the last compression stage and the branch intended for recirculation of the final compressed gas flow, the volume of gas that must be disposed of in the event of the device being switched off is also reduced. Likewise, by eliminating the need for a cooling device, the device has fewer dead spaces, which reduces the flushing time when flushing the device if necessary. In addition, the settle-out pressure was reduced by eliminating the need for a cooler and by switching the bypasses according to the invention.

A further advantage of the device and method according to the invention is that the cooling devices used according to the invention can be standardized in their dimensions. Compared with the prior art, Due to the inventive switching of the bypasses, a smaller volume flow, adapted to the pumping limits of the front compressor stages, is passed through the first cooling device than in the prior art. This means that the first cooling device can be made slightly smaller in size. This volume flow also passes through the last cooling device and is only drawn off as a bypass behind it. In addition, the bypass from the last compressor stage is routed in front of the last cooling device, ie the last cooling device is subjected to a larger volume flow than in the prior art. This means that its dimensions are slightly increased, which enables uniform dimensioning of all cooling devices.

1. a) Bereitstellung eines Gasstroms, enthaltend mindestens eine gasförmige Verbindung,
2. b) Einbringen des besagten Gasstroms über eine Zuleitung in eine erste Kompression, darin durchlaufend zumindest die folgenden Teilschritte:
   • b1) Einbringung und Komprimierung des eingebrachten Gasstroms in einer ersten Kompressorstufe,
   • b2) Ausbringung des komprimierten Gasstroms,
3. c) Einbringen des zuvor ausgebrachten komprimierten Gasstroms in eine weitere Kompression, enthaltend mindestens einen weiteren Kompressionsschritt, wobei in jedem durchgeführten, weiteren Kompressionsschritt zumindest
   • mindestens eine Kühlung des eingebrachten Gasstroms in einer für diesen Kompressionsschritt eigenen Kühlvorrichtung erfolgt und
   • danach eine Komprimierung des zuvor gekühlten Gasstroms in einer für diesen Kompressionsschritt eigenen Kompressorstufe erfolgt,
   mit der Maßgabe, dass dabei zumindest die folgenden Teilschritte durchlaufen werden:
   • c1) Einbringen des ausgebrachten komprimierten Gasstromes in die eigene Kühlvorrichtung, und Abkühlung des zur Kühlung eingebrachten, komprimierten Gasstromes, und Ausbringung des gekühlten Gasstroms,
   • c2) Einbringung zumindest eines Teils des ausgebrachten gekühlten Gasstroms in die eigene Kompressorstufe und Komprimierung darin,
   • c3) Ausbringung des komprimierten Gasstroms,
   • c4) gegebenenfalls Wiederholung der Schritte c1) bis c3) für die Durchführung mindestens eines weiteren Kompressionsschrittes,
   wobei nach Abschluss von Schritt c) von dem daraus in einer Ableitung ausgebrachten komprimierten Gasstrom ein Teil als Bypass-Gasstrom in einen Bypass abgezweigt, vor die letzte Kühlvorrichtung des Schrittes c) zurückgeführt und mit dem zur Kühlung und anschließenden Einbringung in die finale Kompressorstufe des Schrittes c) vorgesehenen Gasstrom vereinigt wird, wobei eine mindestens ein Ventil enthaltende Durchflussregelung die über den Bypass-Gasstrom im Bypass zurückzuführende Gasmenge steuert und dabei den Durchfluss des Gasstromes durch die finale Kompressorstufe des Schrittes c) regelt.

A first subject of the invention is a method for compressing gas of a gas stream, comprising at least the steps

1. a) providing a gas stream containing at least one gaseous compound,
2. b) introducing said gas stream via a feed line into a first compression, therein passing through at least the following sub-steps:
   • b1) introducing and compressing the introduced gas stream in a first compressor stage,
   • b2) discharge of the compressed gas stream,
3. c) introducing the previously discharged compressed gas stream into a further compression, comprising at least one further compression step, wherein in each further compression step carried out at least
   • at least one cooling of the introduced gas stream takes place in a cooling device dedicated to this compression step and
   • the previously cooled gas stream is then compressed in a compressor stage dedicated to this compression step,
   provided that at least the following sub-steps are carried out:
   • c1) introducing the discharged compressed gas stream into the cooling device, cooling the compressed gas stream introduced for cooling, and discharging the cooled gas stream,
   • c2) introducing at least part of the cooled gas stream discharged into the compressor stage and compressing it therein,
   • c3) discharge of the compressed gas stream,
   • c4) if necessary, repeating steps c1) to c3) to carry out at least one further compression step,
   wherein after completion of step c), a portion of the compressed gas stream discharged therefrom in a discharge line is branched off as a bypass gas stream into a bypass, returned before the last cooling device of step c) and combined with the gas stream intended for cooling and subsequent introduction into the final compressor stage of step c), wherein a flow control containing at least one valve controls the amount of gas to be returned via the bypass gas stream in the bypass and in doing so regulates the flow of the gas stream through the final compressor stage of step c).

It is preferred according to the invention if the gas stream discharged from the final compressor stage does not pass through a cooling device between the discharge of the compressed gas stream from the final compressor stage into the discharge line and the branching of the bypass gas stream provided for the removal of the bypass gas stream in the discharge line.

The gas flow provided in the method according to the invention experiences a pressure increase through the individual compressor stages along the flow direction from the introduction into the compression and its compressor stages to the discharge of the compressed gas of the final compression after each compression. The said flow direction of the gas flow thus corresponds to the pumping direction of the compressor stages. A "compressed gas flow" is understood to mean the part of the gas flow that has already passed through at least one compressor stage.

A "bypass" is understood to mean a fluid connection in which at least a part of the compressed gas flow is passed past at least one compressor stage against the pumping direction of the compressor stages and is reunited with the gas flow.

According to the invention, a "fluid connection" is understood to mean a device part that connects system parts to one another and through which a substance, which can be present in any state of aggregation, can be transported from one system part to the next, for example a supply line in the form of a pipe.

A "bypass gas stream" is understood to mean a gas stream branched off from a compressed gas stream, which is returned through a bypass past at least one compressor stage against the pumping direction of the compressor stages and is recombined at a position of the gas stream with a lower pressure than at the branch made.

According to the invention, each compressor stage is a turbo compressor stage.

The gas stream provided according to step a) contains at least one gaseous compound. The totality of all compounds present in the gas stream provided is referred to as the gas composition of the gas stream.

The process according to the invention is particularly advantageous in a further embodiment in which the gas composition of the gas stream provided according to step a) contains at least one halogen-containing gas selected from at least one gaseous compound of halogen, hydrogen halide or mixtures thereof, for example at least 90% by weight of halogen based on the total weight of the gas composition, as at least one gaseous compound. The use of an introduced gas stream containing at least chlorine gas, for example at least 90% by weight of chlorine gas based on the total weight of the gas composition, as at least one gaseous compound has proven particularly preferred.

For compression, the gas stream provided in step a) of the method according to the invention is introduced via the feed line into a compressor unit which contains at least two compressor stages - the first compressor stage and the final compressor stage. The compressor unit is a turbo compressor with several compressor stages.

In the method of the invention, the gas stream provided in step a) is first introduced in step b) via a feed line into a first compression, in which the gas stream is first introduced into a first compressor stage and compressed there, and the compressed gas stream is discharged again.

After this first compression according to step b), the method according to the invention provides that in step c) the compressed gas stream previously discharged from step b) is introduced into a further compression comprising at least one further compression step, wherein in each further compression step carried out at least at least one cooling of the introduced gas stream takes place in a cooling device dedicated to this compression step and
The previously cooled gas stream is then compressed in a separate compressor stage for this compression step.

• c1) Einbringen des ausgebrachten komprimierten Gasstromes in die eigene Kühlvorrichtung, und Abkühlung des zur Kühlung eingebrachten, komprimierten Gasstromes, und Ausbringung des gekühlten Gasstroms,
• c2) Einbringung zumindest eines Teils des ausgebrachten gekühlten Gasstroms in die eigene Kompressorstufe und Komprimierung darin,
• c3) Ausbringung des komprimierten Gasstroms,
• c4) gegebenenfalls Wiederholung der Schritte c1) bis c3) für die Durchführung mindestens eines weiteren Kompressionsschrittes.

The gas flow is guided through each of the further compression steps of step c) in such a way that the gas flow compressed in a compression step of step c) is either the final compressed gas flow or is introduced into a next compression step, whereby a separate cooling device and a separate compressor stage are used for this next compression step as previously defined. Several of these compression steps can be carried out in step c). Thus, at least the following sub-steps are carried out in step c):

• c1) introducing the discharged compressed gas stream into the cooling device, cooling the compressed gas stream introduced for cooling, and discharging the cooled gas stream,
• c2) introducing at least part of the cooled gas stream discharged into the compressor stage and compressing it therein,
• c3) discharge of the compressed gas stream,
• c4) if necessary, repeating steps c1) to c3) to carry out at least one further compression step.

According to step c) of the method according to the invention, the sequence of steps c1) to c3) is carried out at least once. The compressor stage that is carried out last in step c), i.e. including possible repetitions of the sequence of steps c1) to c3), is also referred to as the final compressor stage. The cooling device that is carried out last in step c), i.e. including possible repetitions of the sequence of steps c1) to c3), is also referred to as the last cooling device. When step c) is completed, the compressed gas stream is discharged from the compressor unit in a discharge line.

According to step c4) of the method, steps c1) to c3) can optionally be repeated at least once with the compressed gas stream previously discharged from step c3). A particularly preferred embodiment of the method according to the invention provides that according to step c) of the method, the sequence of steps c1) to c3) is carried out three times, and steps c1) to c3) according to step c4) are thus carried out twice, each using a separate cooling device and in a separate compressor stage with the compressed gas stream emitted from the previous step c3).

The cooling devices used in the method according to the invention in step c) to cool the compressed gas stream cool the previously compressed gas stream before at least a portion of it is introduced into a further compression step. Said cooling devices are preferably heat exchangers. "At least a portion" in this context means that either the gas stream in question is introduced completely or partially, depending on whether or not a bypass gas stream is explicitly discharged before introduction.

Part of the cooling capacity of said cooling devices can be provided for the amount of gas returned as a bypass gas flow without using additional energy if the gas has a positive Joule-Thomson coefficient. In this case, the gas cools down during adiabatic expansion in the valve for regulating the bypass gas flow.

For regulating the recirculated bypass gas flow, a surge limit valve is preferably used as the valve, with the valve more preferably being selected from a degree seat valve or rotary cone valve. In one embodiment of the method, the valve, which is more preferably designed as a pressure surge valve, degree seat valve or rotary cone valve, has a passage with a diameter of at most 350 mm, particularly preferably at most 200 mm.

In a preferred embodiment, after at least one compressor stage of the process, a portion of the compressed, cooled gas stream is branched off as a bypass gas stream downstream of the cooling device of the following compression step and returned to the gas stream upstream of the compressor stage and combined with this gas stream. The size of this bypass gas stream is regulated by means of a valve in which the bypass gas stream expands adiabatically and cools further if the gas has a positive Joule-Thomson coefficient.

If the source for the gas stream provided in step a) supplies a gas stream with a variable volume flow during the process (e.g. a gas production plant connected for the provision of the gas stream, such as a chlor-alkali electrolysis plant), in a preferred embodiment of the process, a portion of the compressed gas is fed via bypasses behind the cooling stages of the respective subsequent compression steps c) to the suction side of the preceding compressor stage and thereby restores the safe operation of the compressor stages of the compression device used. However, the operation of the bypasses requires additional cooling capacity from the cooling stages, which in turn leads to higher energy consumption of the process.

A preferred embodiment of the method is therefore characterized in that, in order to regulate the gas flow after completion of at least one sequence of steps c1) to c3) of step c), a portion of the gas flow from step c1 is branched off into a bypass, returned past at least one compressor stage from at least one step selected from step b) or step c) and recombined with the gas flow, wherein in the bypass the size of the bypass gas flow is preferably regulated by at least one valve, wherein the bypass gas flow is further cooled by the adiabatic expansion at the valve if the gas has a positive Joule-Thomson coefficient.

A particularly preferred embodiment of the method is characterized in that a further bypass gas stream is branched off from the cooled gas stream after the last cooling step c1) of step c) and before entering the final compressor stage of step c) in a further bypass, returned past the compressor stages of steps c) and b), and combined with the gas stream of step a) before it is introduced into step b). In this case, a flow control containing at least one further valve controls the amount of gas to be returned via the bypass gas stream in the further bypass and thus regulates the flow of the gas stream through the compressor stage of step b).

An embodiment is preferred according to the invention in which the bypass gas stream removed after the final compressor stage is returned before the last cooling device of step c). It has been observed that the bypass gas stream can be pre-cooled in the bypass by at least one adiabatic expansion taking place at the valve if the gas composition of the gas stream has a positive Joule-Thomson coefficient. In an embodiment that is particularly preferred according to the invention, the compressed gas stream does not pass through a cooling device between the discharge of the compressed gas stream from the final compressor stage into the discharge line and the branching of the bypass gas stream contained in the discharge line.

A particularly preferred embodiment of the method according to the invention provides that according to step c) of the method, the sequence of steps c1) to c3) is carried out three times, the Steps c1) to c3) are repeated twice in accordance with step c4), each in a separate cooling device and in a separate compressor stage, using the compressed gas stream emitted from the previous step c3).

• c1) Einbringen des ausgebrachten komprimierten Gasstromes in die eigene Kühlvorrichtung, und Abkühlung des zur Kühlung eingebrachten, komprimierten Gasstromes, und Ausbringung des gekühlten Gasstroms,
• c2) Einbringung zumindest eines Teils des ausgebrachten gekühlten Gasstroms in die eigene Kompressorstufe und Komprimierung darin,
• c3) Ausbringung des komprimierten Gasstroms, und erneutem Einbringen zumindest eines Teils des aus Schritt c3) ausgebrachten komprimierten und abgekühlten Gasstroms in eine weitere zusätzliche Kompression, darin durchlaufend zumindest die folgenden Schritte:
  • c1-1) Einbringen des ausgebrachten komprimierten Gasstromes in die eigene Kühlvorrichtung, und Abkühlung des zur Kühlung eingebrachten, komprimierten Gasstromes, und Ausbringung des gekühlten Gasstroms,,
  • c2-1) Einbringung des ausgebrachten gekühlten Gasstroms in die eigene Kompressorstufe und Komprimierung darin,
  • c3-1) Ausbringung des komprimierten Gasstroms,
    und erneutem Einbringen zumindest eines Teils des aus Schritt c3-1) ausgebrachten komprimierten und abgekühlten Gasstroms in eine weitere zusätzliche Kompression, darin durchlaufend zumindest die folgenden Schritte:
  • c1-2) Einbringen zumindest eines Teils des ausgebrachten komprimierten Gasstromes in die eigene Kühlvorrichtung, und Abkühlung des zur Kühlung eingebrachten, komprimierten Gasstromes, und Ausbringung des gekühlten Gasstroms,
  • c2-2) Einbringung des ausgebrachten gekühlten Gasstroms in die eigene Kompressorstufe und Komprimierung darin,
  • c3-2) Ausbringung des komprimierten Gasstroms in einer Ableitung,
  wobei nach Abschluss von Schritt c) von dem daraus in der Ableitung ausgebrachten komprimierten Gasstrom ein Teil als Bypass-Gasstrom in einen Bypass abgezweigt, vor die Kühlvorrichtung des Schrittes c1-2) zurückgeführt und mit dem zur Kühlung und anschließenden Einbringung in die finale Kompressorstufe des Schrittes c) vorgesehenen Gasstrom vereinigt wird, wobei eine mindestens ein Ventil enthaltende Durchflussregelung die über den Bypass-Gasstrom im Bypass zurückzuführende Gasmenge steuert und dabei den Durchfluss des Gasstromes durch die finale Kompressorstufe des Schrittes c) regelt. Alle zuvor genannten vorzugsweisen Ausführungsformen von Merkmalen dieser besonders bevorzugten Ausführungsform gelten für diese besonders bevorzugte Ausführungsform mutatis mutandis ebenfalls als vorzugsweise Ausführungsformen dieser Merkmale.

A particularly preferred embodiment of the method is thus characterized in that step c) is carried out by introducing the compressed gas stream discharged from step b) into an additional compression, therein passing through at least the following sub-steps:

• c1) introducing the discharged compressed gas stream into the cooling device, cooling the compressed gas stream introduced for cooling, and discharging the cooled gas stream,
• c2) introducing at least part of the cooled gas stream discharged into the compressor stage and compressing it therein,
• c3) discharging the compressed gas stream, and reintroducing at least a portion of the compressed and cooled gas stream discharged from step c3) into a further additional compression, therein undergoing at least the following steps:
  • c1-1) introducing the discharged compressed gas stream into the cooling device, and cooling the compressed gas stream introduced for cooling, and discharging the cooled gas stream,
  • c2-1) introducing the cooled gas stream into the compressor stage and compressing it therein,
  • c3-1) discharge of the compressed gas stream,
    and reintroducing at least a portion of the compressed and cooled gas stream discharged from step c3-1) into a further additional compression, therein undergoing at least the following steps:
  • c1-2) introducing at least part of the discharged compressed gas stream into the cooling device itself, and cooling the compressed gas stream introduced for cooling, and discharging the cooled gas stream,
  • c2-2) introducing the cooled gas stream into the compressor stage and compressing it therein,
  • c3-2) discharge of the compressed gas stream into a discharge line,
  wherein after completion of step c), a portion of the compressed gas stream discharged therefrom in the discharge line is branched off as a bypass gas stream into a bypass, returned in front of the cooling device of step c1-2) and combined with the gas stream intended for cooling and subsequent introduction into the final compressor stage of step c), wherein a flow control containing at least one valve controls the amount of gas to be returned via the bypass gas stream in the bypass and in doing so regulates the flow of the gas stream through the final compressor stage of step c). All of the above-mentioned preferred embodiments of features of this particularly preferred embodiment also apply to this particularly preferred embodiment mutatis mutandis as preferred embodiments of these features.

The method according to the invention and the other objects of the invention described below can be combined in a further preferred embodiment with a liquefaction of substances that are gaseous under standard conditions. In this case, said gaseous substances are preferably liquefied for purification. For this purpose, a gas (in particular compressed gas from the compressed gas stream discharged from the final compressor stage of the method according to the invention into the discharge line) is liquefied and stored under pressure (in particular at a relative pressure based on the atmospheric pressure (overpressure) in the range of 2.5 to 13 bar) in a buffer tank. If the liquefied gas is to be removed from the buffer tank again, at least part of the liquefied gas is usually led out of the buffer tank and converted into a gas stream in an evaporator with the addition of heat. This gas stream is advantageously passed into a preheating device for further transport and heated there by further heat input, in particular superheated. For this heat input, the heat of the compressed gas flow discharged from the final compressor stage into the discharge line can be used for heat integration. In this embodiment of the method according to the invention, this heat integration step takes place after the branching of the bypass gas flow from the discharge line according to the invention.

If gas, preferably gas from the gas composition of the said final compressed gas stream, is liquefied and introduced into a buffer vessel and/or stored, it has

Within the scope of the embodiment of the method according to the invention, it has proven to be particularly preferred if a liquefied gas taken from a buffer tank is fed to a preheating device after the evaporation step as a gas stream to be heated and in this preheating device the heat of the gas stream discharged from the final compressor unit is used as a heat source for heating, in particular superheating, the said gas stream to be heated. In this case, no material mixing of the gas streams involved takes place. Advantageously, the gas stream discharged from the final compressor stage into the discharge line, compressed and heated by compression, can therefore be used for heat integration as a heat source for a subsequent process step, in particular for heating a gas, in particular a gas (preferably a halogen gas) with a relative pressure based on the atmospheric pressure (overpressure) in the range of 2.5 to 13 bar. Within the scope of a preferred embodiment of the invention, the compressed gas stream discharged from the final compressor stage of step c) and located in the discharge line is fed, after the bypass gas stream has been branched off, to a device for heating a further gas stream (in particular a further halogen gas stream) as a heat source. The pressure of the gas stream to be heated is preferably in the aforementioned preferred pressure range.

The further gas stream to be heated is, of course, different from the compressed gas stream resulting from the final compression, particularly in terms of temperature and pressure.

The further gas stream to be heated in the preheating device, in all of the aforementioned embodiments, further preferably contains at least 90% by weight of halogen, in particular at least 90% by weight of chlorine gas.

• der aus der finalen Kompressorstufe des Schrittes c) in die Ableitung ausgebrachte, komprimierte Gasstrom hinter der Abzweigung des Bypass-Gasstromes in einen Strömungsweg mindestens einer Vorwärmvorrichtung für einen weiteren Gasstrom eingebracht sowie nach Abgabe von Wärme wieder herausgeführt und
• in einen weiteren davon getrennten Strömungsweg derselben Vorwärmvorrichtung der weitere Gasstrom zur Erhitzung eingebracht, wobei besagter weitere Gasstrom durch Wärmeaustausch mit dem komprimierten Gasstrom der finalen Kompressorstufe (F) in der Vorwärmvorrichtung erhitzt und aus der Vorwärmvorrichtung als erhitzter Gasstrom herausgeführt wird.

In a further preferred embodiment of the invention,

• the compressed gas stream discharged from the final compressor stage of step c) into the discharge line is introduced into a flow path of at least one preheating device for a further gas stream behind the branching of the bypass gas stream and is discharged again after heat has been released and
• the further gas stream for heating is introduced into a further separate flow path of the same preheating device, wherein said further gas stream is heated by heat exchange with the compressed gas stream of the final compressor stage (F) in the preheating device and is led out of the preheating device as a heated gas stream.

Preferably, the pressure of the further gas stream before introduction into the preheating device is in the aforementioned preferred pressure range.

If the gas to be heated in the preheating device is previously taken from a buffer tank as a liquid (in particular at a relative pressure with respect to atmospheric pressure (overpressure) in the range of 2.5 to 13 bar), this liquefied gas must first be vaporized, thereby obtaining the additional gas flow intended for heating described above. This additional gas flow is introduced into the preheating device for this purpose.

To evaporate the liquefied gas, in particular the chlorine, from the buffer tank, the compressed gas stream emerging from the preheating device is preferably used as a heat source. For this purpose, it is preferred if the compressed gas stream discharged from the preheating device is introduced as a heat source into a flow path of an evaporation device, cooled by releasing heat and at least partially liquefied and then discharged again, and a liquefied gas is taken from a buffer tank and introduced into another, different flow path of the evaporation device, wherein said liquefied gas is evaporated by heat exchange with the compressed gas stream of the final compressor stage in the evaporation device and is discharged from the preheating device as another gas stream. There is no material mixing of the streams involved.

If a liquefied gas, in particular chlorine, is evaporated at a relative pressure based on the atmospheric pressure (overpressure) in the range of 2.5 to 13 bar, the evaporated gas, in particular chlorine gas, usually exits the evaporation device at the dew point and is therefore introduced into the preheating device for heating, in particular superheating, within the scope of the aforementioned preferred embodiment of the invention.

The gas stream heated, in particular superheated, in the preheating device is, for example, delivered to a consumer via a pipeline after leaving the preheating device. Due to its heating, in particular superheating, the risk of condensation of the gas, in particular the chlorine, in the pipeline to the consumer is significantly reduced.

• mindestens eine Zuleitung für einen mindestens eine gasförmige Verbindung enthaltenden Gasstrom zu einer Verdichtereinheit, sowie mindestens eine Ableitung des komprimierten Gasstroms aus der Verdichtereinheit,
• eine Verdichtereinheit, enthaltend zumindest eine erste Kompressorstufe und eine finale Kompressorstufe, wobei die Zuleitung mit dem Gaseinlass der ersten Kompressorstufe in Fluidverbindung steht und der Gasauslass der ersten Kompressorstufe mit dem Gaseinlass einer letzten Kühlvorrichtung, sowie der Gasauslass der letzten Kühlvorrichtung mit dem Gaseinlass der finalen Kompressorstufe, sowie die Ableitung mit dem Gasauslass der finalen Kompressorstufe in Fluidverbindung steht,
• mindestens einen ersten Bypass, der die Ableitung mit der Fluidverbindung verbindet, die sich zwischen der letzten Kühlvorrichtung und der unmittelbar davor liegenden Kompressorstufe befindet, wobei mit einer im ersten Bypass befindlichen, mindestens ein Ventil enthaltenden ersten Durchflussregelung die im Bypass-Gasstrom geführte Gasmenge steuerbar ist und dadurch der Durchfluss des Gasstromes durch die finale Kompressorstufe regelbar ist,
• mindestens einen mit einer zweiten Durchflussregelung versehenen zweiten Bypass, wobei dieser die zwischen letzter Kühlvorrichtung und finaler Kompressorstufe befindliche Fluidverbindung mit der Zuleitung verbindet.

The method according to the invention can be carried out excellently in a device for compressing gas from a gas stream prepared for this purpose. A further subject of the invention is therefore a device for compressing gas from a gas stream, comprising

• at least one supply line for a gas stream containing at least one gaseous compound to a compressor unit, and at least one discharge line of the compressed gas stream from the compressor unit,
• a compressor unit comprising at least a first compressor stage and a final compressor stage, wherein the supply line is in fluid communication with the gas inlet of the first compressor stage and the gas outlet of the first compressor stage is in fluid communication with the gas inlet of a final cooling device, and the gas outlet of the last cooling device is in fluid communication with the gas inlet of the final compressor stage, and the discharge line is in fluid communication with the gas outlet of the final compressor stage,
• at least one first bypass which connects the discharge line to the fluid connection which is located between the last cooling device and the compressor stage immediately preceding it, wherein the amount of gas guided in the bypass gas flow can be controlled by means of a first flow control located in the first bypass and containing at least one valve, and the flow of the gas flow through the final compressor stage can thereby be regulated,
• at least one second bypass provided with a second flow control, which connects the fluid connection between the last cooling device and the final compressor stage to the supply line.

As is necessary for the embodiments of the method according to the invention with at least one repetition of steps c1) to c3), in a preferred embodiment of the device, said compressor unit contains a further compressor stage for each intended repetition of said steps, which is integrated into the device together with a further cooling device.

Thus, a device is preferably suitable according to the invention in which the compressor unit (4) contains at least one further inserted compressor stage, with the proviso that for each further inserted compressor stage there is a separate cooling device connected upstream of the respective inserted compressor stage, with the proviso that the The gas outlet of the first compressor stage is in fluid communication with the inlet of an additional, inserted cooling device instead of the fluid connection with the inlet of the last cooling device, the outlet of the inserted cooling device is in fluid communication with the inlet of the inserted compressor stage, and the outlet of the inserted compressor stage is in fluid communication either with the inlet of at least one further additional combination of cooling device and compressor stage or with the inlet of the last cooling device.

Each repetition of steps c1) to c3) therefore requires the insertion of an insert element. Each of these insert elements is inserted between the first compressor stage and the last cooling device, with each insert element containing a cooling device and a compressor stage.

The cooling device of the insert element is always located on the suction side of the compressor stage of the same insert element. This is ensured by the gas outlet of the cooling device being in fluid communication with the gas inlet of the compressor stage of the insert element. An example of such an insert element is shown in Fig.4a illustrated. If several insert elements are used, they are first linked in series in such a way that the gas outlet of the compressor stage of one insert element is connected to the gas inlet of the cooling device of the next insert element. The gas inlet of the linked insert elements is the gas inlet of a cooling device in fluid connection with the gas outlet of the first compressor stage and the gas outlet of the linked insert elements is the gas outlet of a compressor stage in fluid connection with the gas inlet of the last cooling device. This is exemplified in Fig.3 illustrated by the linked insertion elements using the dashed line.

It is also possible within the scope of a further embodiment that at least one of the slide-in elements used additionally contains a bypass provided with a flow control, whereby this bypass is removed after the outlet of the compressor stage of the slide-in element and is returned before the inlet of the cooling device of the same slide-in element. Such a slide-in element with a bypass is shown as an example in Fig.4b Another possibility is that at least one of the slide-in elements used additionally contains a bypass provided with a flow control, whereby this bypass is located after the outlet of the cooling device of the insert element and returned to the inlet of the compressor stage of the preceding insert element.

It is advantageous according to the invention if, in a preferred embodiment, the device does not have any further cooling device after the gas outlet from the final compressor stage of the device.

Preferably, the compressor stages of the device are operated with a suction pressure control, since the suction pressure of the compressor stage is influenced by the amount of gas provided by the supply line. For this purpose, the device preferably has a suction pressure control.

Generally, according to the invention, devices are preferably suitable in which each of the said bypasses has a valve, whereby the flow of the gas stream in the affected bypass can be regulated by a control unit. The aim of the regulation is to provide a sufficient amount of gas for a surge limit regulation of the compressor stage upstream of the bypass. Furthermore, an adiabatic expansion of the gas takes place at the valve while cooling if the gas has a positive Joule-Thomson coefficient.

Furthermore, in one embodiment of the device, the flow control valve can act as a bypass control in the sense of a safety valve in the event of a complete failure of the gas supply in the supply line or a large pressure difference between the compressed gas flow after completion of the final compression and the gas flow supplied in the supply line to prevent a backflow of the gas through the entire compressor unit. In this embodiment, the bypass has two valves installed in parallel, each with flow control, whereby both valves can be used for adiabatic expansion. At least one of the valves preferably has a passage diameter of at least 50 mm, preferably more than 200 mm; whereby this one valve can also be used as a safety valve as described above.

As previously described for the execution of the method according to the invention and its embodiments, preferred devices are characterized in that said cooling devices cool the gas stream according to the heat exchanger principle via a cooled medium as cooling.

In a very special embodiment of the device, the gas discharged from the device's outlet and compressed by the final compressor stage Gas flow is no longer introduced into a cooling device and cooled. As a result, this very special embodiment contains one cooling device less than the number of compressor stages.

For example, the compressor unit described can be used in conjunction with chlor-alkali electrolysis or oxidation of hydrogen chloride (Deacon process) to compress the chlorine gas obtained therefrom in such a way that it can be liquefied with common coolants in several cooling stages or in a liquefaction device designed as a flash cooler. If the liquefaction device for the liquefaction of the compressed gas stream discharged from the final compressor stage is designed in such a way that liquid chlorine from a buffer tank is evaporated as a liquid to be heated in order to cool and liquefy the compressed gas stream, e.g. compressed chlorine gas, using the resulting cold, then compressed chlorine gas from the final compressor stage can advantageously be used as a heat source for the evaporation of the liquid chlorine gas originating from the buffer tank. For this purpose, preferably at least two devices are required, at least one device for evaporating the liquefied gas, in particular chlorine gas, and at least one preheating device for heating the gas stream resulting from the evaporation. The compressed gas stream, in particular chlorine gas stream, located in the discharge line behind the branch of the first bypass from the final compressor stage is first fed into the preheating device as a heat source and then from the preheating device into the evaporation device. In the opposite direction, the liquefied gas is first fed from the buffer tank into the evaporation device and the further gas stream obtained from it after evaporation is fed into the preheating device.

• mindestens ein Strömungsweg mindestens einen Einlass für komprimiertes Gas aufweist, der hinter dem ersten Bypass (6a) mit der Ableitung (3) für den final komprimierten Gasstrom aus der Verdichtereinheit (4) in Fluidverbindung steht, sowie mindestens einen Auslass für das komprimierte Gas aufweist; und
• mindestens ein weiterer Strömungsweg mindestens einen Einlass für einen weiteren Gasstrom, insbesondere Chlorgas, aufweist, der in Fluidverbindung mit einer Quelle für besagten weiteren Gasstrom steht und mindestens einen Auslass für den erhitzten Gasstrom, insbesondere für erhitztes Chlorgas, aufweist.

In this embodiment, the device according to the invention preferably additionally contains at least one preheating device as a heat exchanger with at least two flow paths, wherein

• at least one flow path has at least one inlet for compressed gas, which is in fluid communication with the discharge line (3) for the final compressed gas flow from the compressor unit (4) behind the first bypass (6a), and at least one outlet for the compressed gas; and
• at least one further flow path has at least one inlet for a further gas stream, in particular chlorine gas, which is in fluid communication with a source of said further gas stream and has at least one outlet for the heated gas stream, in particular for heated chlorine gas.

• mindestens ein Strömungsweg mindestens einen Einlass für komprimiertes Gas aufweist, der mit der Vorwärmvorrichtung über den Auslass für den komprimierten Gasstrom in Fluidverbindung steht, sowie mindestens einen Auslass für das komprimierte, gekühlte und zumindest teilweise verflüssigte Gas aufweist; und
• mindestens ein weiterer Strömungsweg mindestens einen Einlass für ein verflüssigtes Gas, insbesondere flüssiges Chlor, aufweist, der in Fluidverbindung mit einer Quelle für besagtes verflüssigtes Gas, bevorzugt mit einem Pufferbehälter für verflüssigtes Gas, besonders bevorzugt für flüssiges Chlor, in Fluidverbindung steht und mindestens einen Auslass für Dampf der besagten Flüssigkeit, insbesondere für Chlorgas, aufweist.

Furthermore, a preferred embodiment of the said device for compression equipped with a preheating device additionally contains at least one evaporation device as a heat exchanger with at least two flow paths, wherein

• at least one flow path has at least one inlet for compressed gas which is in fluid communication with the preheating device via the outlet for the compressed gas stream, and at least one outlet for the compressed, cooled and at least partially liquefied gas; and
• at least one further flow path has at least one inlet for a liquefied gas, in particular liquid chlorine, which is in fluid communication with a source of said liquefied gas, preferably with a buffer vessel for liquefied gas, particularly preferably for liquid chlorine, and has at least one outlet for vapor of said liquid, in particular for chlorine gas.

The subject matter of the device for compressing gas from a gas stream, as well as its previously described embodiments, are suitable for carrying out the inventive method of the first subject matter of the invention and are preferably used for this purpose. A further subject matter of the invention is therefore the use of a corresponding device for compressing gas from a gas stream for compressing a gas stream according to a method of the first subject matter of the invention. The invention is illustrated below by way of example without being limited thereto.

1

erste Kompressorstufe (Turbokompressorstufe)

E

zwischen erste und finale Kompressorstufe eingeschobene Kompressorstufe einer Turbokompressor-Vorrichtung

E1

erste eingeschobene Kompressorstufe (Turbokompressorstufe)

E2

zweite eingeschobene Kompressorstufe (Turbokompressorstufe)

F

finale Kompressorstufe (Turbokompressorstufe)

2

Zuleitung zur Verdichtereinheit 4 für einen mindestens eine gasförmige Verbindung enthaltenden Gasstrom

3

Ableitung aus der Verdichtereinheit für den final komprimierten Gasstrom

4

Verdichtereinheit, enthaltend 1, F, 7 und 8, sowie sofern eingezeichnet E, E1 oder E2

5

Durchflussregelung, enthaltend 9 und10

5a

erste Durchflussregelung, enthaltend 9 und 10

5b

zweite Durchflussregelung, enthaltend 9 und 10

6

Bypass

6a

erster Bypass

6b

zweiter Bypass

7

Antriebsaggregat für die Rotation der Achse 8

8

Achse

9

Steuereinheit

10

Ventil

E

eingeschobene Kompressorstufe

WAGE

eingeschobene Kühlvorrichtung

WA0E1

erste eingeschobene Kühlvorrichtung

WA0E2

zweite eingeschobene Kühlvorrichtung

WA00F

letzte Kühlvorrichtung

legend of the figures Fig.1 to Fig.5 :

1

first compressor stage (turbo compressor stage)

E

compressor stage of a turbo compressor device inserted between the first and final compressor stage

E1

first inserted compressor stage (turbo compressor stage)

E2

second inserted compressor stage (turbo compressor stage)

F

final compressor stage (turbo compressor stage)

2

Supply line to the compressor unit 4 for a gas stream containing at least one gaseous compound

3

discharge from the compressor unit for the final compressed gas stream

4

Compressor unit, containing 1, F, 7 and 8, and if indicated E, E1 or E2

5

flow control, containing 9 and 10

5a

first flow control, containing 9 and 10

5b

second flow control, containing 9 and 10

6

bypass

6a

first bypass

6b

second bypass

7

drive unit for the rotation of axis 8

8

axis

9

control unit

10

valve

E

inserted compressor stage

WAGE

inserted cooling device

WA0E1

first inserted cooling device

WA0E2

second inserted cooling device

WA00F

last cooling device

In the figures Fig.1 to Fig.5 A fluid connection between the individual compressor stages of the compressor unit, represented by a thick line, symbolizes the flow of the gas flow caused by the pumping effect of the compressor stages with the imposed flow direction from the suction side of the compressor unit to the discharge of the finally compressed gas out of the compressor unit. This flow direction is correspondingly with arrowheads along the fluid connection and is highlighted again by an arrow at the beginning and end.

In the figures Fig. 1 to Fig. 5 Fluid connections, which are shown by a thin line, correspond to the bypasses in which the gas flow flows due to the pressure differences in the opposite direction to the flow direction of the main gas flow imposed by the pumping action of the compressor stages during the compression process (bypass gas flow). This flow direction is marked accordingly with arrowheads along the fluid connection

• mindestens eine Zuleitung 2 für einen mindestens eine gasförmige Verbindung enthaltenden Gasstrom zur Verdichtereinheit 4, sowie mindestens eine Ableitung 3 des komprimierten Gasstroms aus der Verdichtereinheit 4,
• eine Verdichtereinheit 4, enthaltend zumindest eine erste Kompressorstufe 1, zwei eingeschobene Kompressorstufen E und eine finale Kompressorstufe F, wobei jeder Kompressorstufe eine separate Kühlvorrichtung nachgeschaltet ist und der Gasauslass jeder Kompressorstufe mit dem Gaseinlass der entsprechenden Kühlvorrichtung in Fluidverbindung steht und der Gasauslass der jeweiligen Kühlvorrichtung mit dem Gaseinlass der nachfolgenden Kompressorstufe in Fluidverbindung steht,
• mindestens einen mit einer Durchflussregelung 5 versehenen Bypass 6, wobei dieser die nach dem Gasauslass der letzten Kühlvorrichtung WA00F befindliche Ableitung mit der Zuleitung 2 verbindet.

In Fig. 1 a prior art device is shown which serves to compress gas from a gas stream, comprising

• at least one supply line 2 for a gas stream containing at least one gaseous compound to the compressor unit 4, and at least one discharge line 3 of the compressed gas stream from the compressor unit 4,
• a compressor unit 4, containing at least a first compressor stage 1, two inserted compressor stages E and a final compressor stage F, wherein each compressor stage is followed by a separate cooling device and the gas outlet of each compressor stage is in fluid communication with the gas inlet of the corresponding cooling device and the gas outlet of the respective cooling device is in fluid communication with the gas inlet of the subsequent compressor stage,
• at least one bypass 6 provided with a flow control 5, which connects the outlet line located after the gas outlet of the last cooling device WA00F with the supply line 2.

The compressor unit 4 is a turbo compressor mechanically driven via an axle 8 by a drive unit 7, comprising said compressor stages connected in series.

The bypass 6 has its own flow control 5 comprising a valve 10 and a control unit 9.

• mindestens eine Zuleitung 2 für einen mindestens eine gasförmige Verbindung enthaltenden Gasstrom zur Verdichtereinheit 4, sowie mindestens eine Ableitung 3 des komprimierten Gasstroms aus der Verdichtereinheit 4,
• eine Verdichtereinheit 4, enthaltend zumindest eine erste Kompressorstufe 1 und eine finale Kompressorstufe F, wobei die Zuleitung 2 mit dem Gaseinlass der ersten Kompressorstufe 1 in Fluidverbindung steht und der Gasauslass der ersten Kompressorstufe 1 mit dem Gaseinlass einer letzten Kühlvorrichtung WA00F, sowie der Gasauslass der letzten Kühlvorrichtung WA00F mit dem Gaseinlass der finalen Kompressorstufe F, sowie die Ableitung 3 mit dem Gasauslass der finalen Kompressorstufe F in Fluidverbindung steht,
• mindestens einen ersten Bypass 6a, der die Ableitung 3 mit der Fluidverbindung verbindet, die sich zwischen der letzten Kühlvorrichtung WA00F und der unmittelbar davor liegenden Kompressorstufe befindet, wobei mit einer im ersten Bypass 6a befindlichen, mindestens ein Ventil 10 enthaltenden ersten Durchflussregelung 5a die im Bypass-Gasstrom geführte Gasmenge steuerbar ist und dadurch der Durchfluss des Gasstromes durch die finale Kompressorstufe F regelbar ist,
• mindestens einen mit einer zweiten Durchflussregelung 5b versehenen zweiten Bypass 6b, wobei dieser die zwischen letzter Kühlvorrichtung WA00F und finaler Kompressorstufe F befindliche Fluidverbindung mit der Zuleitung 2 verbindet.

Fig.2 on the other hand shows an example of a device according to the invention for compressing gas of a gas stream, containing

• at least one supply line 2 for a gas stream containing at least one gaseous compound to the compressor unit 4, and at least one discharge line 3 of the compressed gas stream from the compressor unit 4,
• a compressor unit 4, containing at least a first compressor stage 1 and a final compressor stage F, wherein the supply line 2 is in fluid communication with the gas inlet of the first compressor stage 1 and the gas outlet of the first compressor stage 1 is in fluid communication with the gas inlet of a last cooling device WA00F, and the gas outlet of the last cooling device WA00F is in fluid communication with the gas inlet of the final compressor stage F, and the discharge line 3 is in fluid communication with the gas outlet of the final compressor stage F,
• at least one first bypass 6a, which connects the discharge line 3 to the fluid connection located between the last cooling device WA00F and the compressor stage immediately preceding it, wherein the amount of gas guided in the bypass gas flow can be controlled by a first flow control 5a located in the first bypass 6a and containing at least one valve 10, and thereby the flow of the gas flow through the final compressor stage F can be regulated,
• at least one second bypass 6b provided with a second flow control 5b, which connects the fluid connection located between the last cooling device WA00F and the final compressor stage F to the supply line 2.

The compressor unit 4 is a turbo compressor mechanically driven via an axle 8 by a drive unit 7, containing said compressor stages.

Each bypass has its own flow control (here: 5a and 5b) containing a valve 10 and a control unit 9.

With the help of the device of Fig.2 a method according to the invention can be carried out in which no repetition according to step c4) is carried out. If at least one repetition according to step c4) of the method according to the invention is to be carried out, the device must be provided with at least one insertion of a Fig.4a or Fig.4b illustrated insert element as a combination of an inserted cooling device WA0E and a compressor stage E inserted on the axis 8 between compressor stage 1 and compressor stage F. The compressed gas flow led out of compressor stage 1 is first led into the inserted cooling device WA0E and then into the inserted compressor stage E. The gas flow led out of compressor stage E can then either be fed into another insert element for a further repetition according to Fig. 4a or Fig.4b of process step c4) or finally into the last cooling device WA00F of step c).

In Fig.5 An example of a device according to the invention for compressing gas from a gas stream is illustrated, which is based on the device according to the invention of Fig.2 is configured, with the difference that between the first compressor stage 1 and the last cooling device WA00F two inserted compressor stages E are positioned as E1 and E2, each of which is preceded by an inserted cooling device WAGE, for E1 the inserted cooling device WA0E1 and for E2 the inserted cooling device WA0E2. The insertion of the corresponding device components starting from the device from Fig.2 , as well as the guidance of the compressed gas flow along the imposed flow direction of the compressed gas flow, which must be ensured in this insertion, is described in Fig.3 illustrated. The Fig.3 The dashed components of the device and the dashed fluid connections apply to the case of insertion, which results in the device of the Fig.5 Without the dashed components of the device, the flow of the compressed gas would have to be guided along the dash-dot line, which would make the device of the Fig.2 results.

Out of Fig.3 It becomes clear that the insertions do not change the guidance of the respective Fig.2 It is possible to insert a plug-in element according to Fig.4b to introduce a further bypass. At least a portion of the compressed gas flow leading out of compressor stage E is removed through the bypass and returned to the cooling device WA0E of the same insert element. A flow control 5 containing at least one valve 10 and a control unit 9 controls the bypass gas flow guided in this bypass.

Claims (14)

Method for compressing gas from a gas stream in a suitable device, comprising at least the steps in the order a) providing a gas stream containing at least one gaseous compound, b) introducing said gas stream via a feed line (2) into a first compression, therein passing through at least the following sub-steps: b1) introducing and compressing the introduced gas stream in a first compressor stage (1), b2) discharge of the compressed gas stream, c) introducing the previously discharged compressed gas stream into a further compression, comprising at least one further compression step, wherein in each further compression step carried out at least at least one cooling of the introduced gas stream takes place in a cooling device dedicated to this compression step and the previously cooled gas stream is then compressed in a compressor stage dedicated to this compression step, provided that at least the following sub-steps are carried out: c1) introducing the discharged compressed gas stream into the cooling device, cooling the compressed gas stream introduced for cooling, and discharging the cooled gas stream, c2) introducing at least part of the cooled gas stream discharged into the compressor stage and compressing it therein, c3) discharge of the compressed gas stream, c4) if necessary, repeating steps c1) to c3) to carry out at least one further compression step, characterized in that after completion of step c), a part of the compressed gas stream discharged therefrom in a discharge line (3) is branched off as a bypass gas stream (6a) into a bypass, returned to the last cooling device of step c) (WA00F) and mixed with the gas stream for cooling and subsequent introduction into the final compressor stage (F) of step c) is combined, wherein a flow control (5a) containing at least one valve (10) controls the amount of gas to be returned via the bypass gas flow in the bypass (6a) and in the process regulates the flow of the gas flow through the final compressor stage (F) of step c). Method according to claim 1, characterized in that from the cooled gas stream after the last cooling step of step c) and before entry into the final compressor stage (F) of step c), a further bypass gas stream is branched off in a further bypass (6b), returned past the compressor stages of steps c) and b), and combined with the gas stream of step a) before its introduction into step b), wherein a flow control (5b) containing at least one further valve (10) controls the amount of gas to be returned via the bypass gas stream in the further bypass (6b) and in the process regulates the flow of the gas stream through the compressor stage of step b). Method according to one of claims 1 or 2, characterized in that at least one surge limit valve is located as valve (10) in the corresponding bypass. Process according to one of the preceding claims, characterized in that in the gas composition of the gas stream provided according to step a), at least one halogen-containing gas selected from at least one gaseous compound of halogen, hydrogen halide or mixtures thereof is contained as at least one gaseous compound. Process according to one of the preceding claims, characterized in that the gas composition of the gas stream provided according to step a) contains at least one halogen-containing gas selected from at least one gaseous compound of halogen, hydrogen halide or mixtures thereof, in particular based on the total weight of the gas composition at least 90 wt.% halogen, as at least one gaseous compound. Method according to one of the preceding claims, characterized in that the compressed gas stream discharged from the final compressor stage of step c) into the discharge line is introduced into a flow path of at least one preheating device for a further gas stream behind the branching of the bypass gas stream and is led out again and into a further separate The further gas stream is introduced for heating purposes via the flow path of the same preheating device, wherein said further gas stream is heated by heat exchange with the compressed gas stream of the final compressor stage in the preheating device and is led out of the preheating device as a heated gas stream. Method according to claim 6, characterized in that the compressed gas stream discharged from the preheating device is introduced as a heat source into a flow path of an evaporation device, cooled by releasing heat and at least partially liquefied and discharged again, and a liquefied gas is taken from a buffer container and introduced into a further, different flow path of the evaporation device, wherein said liquefied gas is evaporated by heat exchange with the compressed gas stream of the final compressor stage in the evaporation device and is led out of the preheating device as a further gas stream. Device for compressing gas of a gas stream, comprising at least one supply line (2) for a gas stream containing at least one gaseous compound to a compressor unit (4), and at least one discharge line (3) of the compressed gas stream from said compressor unit (4), said compressor unit (4) comprising at least a first compressor stage (1) and a final compressor stage (F), wherein the supply line (2) is in fluid communication with the gas inlet of the first compressor stage (1) and the gas outlet of the first compressor stage (1) is in fluid communication with the gas inlet of a final cooling device (WA00F), and the gas outlet of the last cooling device (WA00F) is in fluid communication with the gas inlet of the final compressor stage (F), and the discharge line (3) is in fluid communication with the gas outlet of the final compressor stage (F), at least one first bypass (6a) which connects the discharge line (3) to the fluid connection which is located between the last cooling device (WA00F) and the compressor stage immediately preceding it, wherein the amount of gas guided in the bypass gas flow can be controlled by a first flow control (5a) located in the first bypass (6a) and containing at least one valve (10), and thereby the flow of the gas flow through the final compressor stage (F) can be regulated, at least one second bypass (6b) provided with a second flow control (5b), which connects the fluid connection between the last cooling device (WA00F) and the final compressor stage (F) to the supply line (2). Device according to claim 8, characterized in that the compressor unit (4) contains at least one further inserted compressor stage (E1 and/or E2), with the proviso that for each further inserted compressor stage (E1 and/or E2) there is a separate cooling device (WA0E1 and/or WA0E2) connected upstream of the respective inserted compressor stage, with the proviso that the gas outlet of the first compressor stage (1) is in fluid connection with the inlet of an additional, inserted cooling device (WA0E1) instead of the fluid connection with the inlet of the last cooling device (WA00F), the outlet of the inserted cooling device (WA0E1) is in fluid connection with the inlet of the inserted compressor stage (E1) and the outlet of the inserted compressor stage (E1) is in fluid connection either with the inlet of at least one further additional combination of cooling device (WA0E2) and compressor stage (E2) or with the inlet of the last cooling device (WA00F). Device according to one of claims 8 or 9, characterized in that said cooling devices cool the gas flow according to the heat exchanger principle via a cooled medium as cooling. Device according to one of claims 8 to 10, characterized in that said compressor unit (4) comprises at least one turbo compressor mechanically driven via an axis (8) and containing said compressor stages. Device according to one of claims 8 to 11, characterized in that it additionally contains at least one preheating device as a heat exchanger with at least two flow paths, wherein - at least one flow path has at least one inlet for compressed gas, which is in fluid communication with the discharge line (3) for the final compressed gas flow from the compressor unit (4) behind the first bypass (6a), and at least one outlet for the compressed gas; and - at least one further flow path has at least one inlet for a further gas stream, in particular chlorine gas, which is in fluid communication with a source for said further gas stream and has at least one outlet for the heated gas stream, in particular for heated chlorine gas. Device according to claim 12, characterized in that it additionally contains at least one buffer tank and at least one evaporation device as a heat exchanger with at least two flow paths, wherein - at least one flow path has at least one inlet for compressed gas which is in fluid communication with the preheating device via the outlet for the compressed gas flow, and at least one outlet for the compressed gas; and - at least one further flow path has at least one inlet for a liquefied gas, in particular liquid chlorine, which is in fluid communication with a source for said liquefied gas, preferably with a buffer container for liquefied gas, particularly preferably for liquid chlorine, and has at least one outlet for vapor of said liquid, in particular for chlorine gas. Use of a device according to one of claims 8 to 13 for compressing a gas stream according to a method according to one of claims 1 to 7.

Images