EP1851432A1

EP1851432A1 - Water injection compressor plant for producing compressed air

Info

Publication number: EP1851432A1
Application number: EP06710516A
Authority: EP
Inventors: Gerd Cromm
Original assignee: GCI Consulting GmbH
Current assignee: GCI Consulting GmbH
Priority date: 2005-02-25
Filing date: 2006-02-21
Publication date: 2007-11-07
Also published as: WO2006090276A1

Abstract

The invention relates to a method for regenerating the internal water circuit of a compressor plant (1) for producing compressed air (46) essentially comprising a compressor stage (2) which is cooled and lubricated by injected water. A compressed air concept comprises other compressed gases, for example oxygen (O2), nitrogen (N2) and/or carbon dioxide (CO2). At least one electronically controlled ultrasonic transmitter (41, 42) transmits ultrasonic waves to water accumulations in the compressor plant (1). The ultrasonic transmitters (41, 42) are arranged on the compressor stages (2) in an air/water separator, in cyclone separators (44), in a water cooler (7) in water filters (14, 26) and/or in water conduits (6, 10).

Description

Water-injected compressor unit for generating compressed air

The invention relates to a method and a device for regenerating internal water circuits of a compressor system for the production of compressed air, which comprise substantially at least one compressor stage cooled by injected water and lubricated. Each compressor stage has at least one water cooler, water filter, air intake filter and air / water separator. Further, the invention relates to applications of the method.

Here and below, the term compressed air includes not only compressed air, but compressed gases in general, z. As oxygen (O ₂ ), nitrogen (N ₂ ) and / or carbon dioxide (CO ₂ ).

There are known compressor systems in which water, preferably tap water, is used as lubricant and coolant. The injection of water into the compressor chamber of the compressor, in which heat is generated by the compression process, simultaneously serves to cool and lubricate and seal the rotors with each other and with the housing on the other hand. Injectors with water injection cooling are more efficient than compressors with other lubricants and coolants such as oils. By using water, condensate treatment and oil disposal can be avoided, which brings economic and environmental benefits.

However, the injection of water in compressors not only brings benefits, but without any special measures also disadvantages. When using conventional materials, caused by the air / water mixture, corrosion damage may occur. This makes the use of corrosion-resistant permanent materials such as stainless steels, ceramics or composite materials required.

Furthermore, the use of water has the disadvantage that microorganisms, for example bacteria and / or germs, form in internal circulatory systems, which as a rule grow rapidly and / or multiply. These negative effects are largely prevented or reduced during normal compressor operation by high and rapid pressure changes in the water circuits. Finally, water in one cycle favors the agglomeration of solid particles.

Despite the arrangement of filters in the water cycle of a compressor with periodic shutdowns, the growth and proliferation of microorganisms and the accumulation of agglomerating solid particles can not be prevented, which leads to continuous operation time to a constantly increasing degree of contamination of the water.

The water must therefore be replaced at comparatively short time intervals, which leads to interruptions in operation and impedes rational operation.

The proportion of microorganisms increasing compressor stoppages can not be avoided, they occur even in rational operation, for example,

in one and two-shift operation, in standby operation of at least one compressor in a compressor system with more than one compressor,

- In the time interval between the switching off of a compressor after reaching a certain Endrucks and its start after reaching a lower discharge pressure, or - during longer periods of downtime, for example at weekends, during company holidays, production-related shutdowns and overhauls.

Kaikabscheidungen form in the water circuits of water-injected compressors at operating temperatures above about 45 ⁰ C. Despite the contribution of ultrapure water and filtered outside air, calcium ions and solid particles can invariably penetrate and, through deposits, especially calcification, impede the mobility of functional components, such as valve tags and rotors, or immovable components, such as seals or radiators, and prematurely replace them or carry out repairs.

The inventor has set itself the task of creating a method and an apparatus of the type mentioned, which prevent the growth and proliferation of microorganisms, lead to the destruction of solid particles and the removal of deposits in the water circuits.

With respect to the method, the object is achieved according to the invention in that at least one electronically controlled ultrasonic transmitter emits ultrasonic waves in water accumulations in the compressor system. Advantageous and further developing embodiments of the method are the subject of dependent claims.

The ultrasonic waves radiated by the ultrasonic transmitters generate the smallest vacuum bubbles in the water, which immediately implode again, which is referred to as the tensile and compressive phases. This creates high local temperatures. At an ultrasonic frequency of about 25 kHz, temperatures of more than 5,000 ° C. and pressures of up to about 500 bar can arise for a short time, which releases large local forces.These high and rapid pressure changes in the water cycle of compressors are able to produce microorganisms, as mentioned, in particular, bacteria and germs to kill. The the ultrasonic waves Inherent energy can also be solid particles! to smash and remove deposits in the water circuits, whereby a potential premature wear of the compressor stage, all functional parts and lines is prevented, so the life of the compressor plant is increased overall.

The ultrasonic waves are emitted at the same or different time intervals, for example electronically controlled according to a stored nominal curve. Accordingly, the ultrasonic waves can be transmitted during the same or different time intervals, also programmatically.

The emission of ultrasonic waves also causes optimal degassing of the guided in the closed circuits water, especially in the air / water. Optimal degassed water

- increases the efficiency of the compressor,

- does not return compressed air to the compressor via the water injection, - cools the recycled water in the water cooler to a lower temperature,

- Leaves the water supply bubble-free to water-lubricated bearings of the compressor and makes them more reliable.

During operation, ultrasound-like pressure waves are generated in the compressors, which can have a comparable effect. The ultrasonic transmitter can additionally emit ultrasonic waves during operation. However, it is of particular importance that ultrasonic waves are emitted during a shorter or longer standstill of a compressor, in particular in water accumulations of the affected water cycle.

In general physical language, vibrations with fre- above 18 kHz referred to as ultrasound. These frequencies are perceived by the human ear usually no more or only as a disturbing noise. The ultrasonic waves radiated by the ultrasonic transmitters in the present case preferably have a frequency of 20 to 35 kHz, in particular 23 to 25 kHz.

As already mentioned, the ultrasonic waves are preferably emitted into areas with water accumulations. This is particularly the case in an air / water separator, in a cyclone with a sump, in a water cooler, in water filters, in a compressed air tank with separated water and / or in pipes for water in general the case. Of course, may be arranged in a compressor plant of these mentioned plant parts or construction elements depending on the complexity of one or more. In a compressor station with several compressor systems all, a group or a single compressor system can be shut down. The generation of ultrasonic waves takes place continuously in all compressor systems or in each case only in concerned stationary compressor systems.

The greater the amplitude of the ultrasonic waves, the more powerful pressure surges are generated, especially in the low frequency range. Agglomerates of microorganisms and possibly secretions, floating and deposited on the surfaces of solid particles and deposits are broken by strong ultrasonic waves and smashed and carried by the water cycle until calmer accumulations of water are reached, where they are possibly further smashed. The killed microorganisms and smashed solid particles sediment in the air / water separator or cyclone separator. There, the swamp formed is periodically drained and replaced if necessary by fresh ultrapure water.

According to a variant of the method, the efficiency of the ultrasonic waves can be increased even further if they are used in chemical reactions known per se. Sent staggered water.

With respect to the compressor system for carrying out the method, the object is achieved according to the invention that are arranged in the compressor stages, in air / Wasserabscheidem, in Zyklonabscheidem, in Druckluftbehältem, in water coolers, in filters and / or in pipelines ultrasonic transmitter. Special and further embodiments of the compressor system are the subject of dependent claims.

In complex cases, the compressor system may also include more than one compressor stage, more than one air / water separator, and / or more than one compressed air tank.

The number of ultrasound transmitters used according to the invention, their activation intensity and activation time depend on the size of the system and the number, position and volume of the water accumulations in the system parts, which form in particular during a shorter or longer standstill. Next plays the number, the design and the performance of the compressor stages used a significant role.

The oil-free Kompressorsstυfen provide clean, high-quality oil-free compressed air for a variety of delicate industries. Even where compressed air or, as mentioned, other compressed gases come into direct contact with persons, animals or the products to be manufactured, this is essential. With the device according to the invention, the method can be used in particular in the food and beverage industry, in the pharmacy, the health care, the electrical engineering and the textile industry.

The invention will be explained in more detail with reference to embodiments shown in the drawing, which are also the subject of dependent claims. They show schematically: - Fig. 1 is a compressor system and

FIG. 2 shows a variant of FIG. 1 with an additional cyclone separator

In a compressor system 1, a compressor stage 2 with a drive motor M above an air / water separator 3 is arranged. Both the compressor stage 2, also called compressor or compressor stage, as well as a cylinder-shaped air / water separator 3 are arranged horizontally in the present case, but both can also be arranged vertically. The air / water separator 3 may also have other than a cylindrical shape.

The driven by the drive motor M compressor stage 2 sucks to be compressed outside air 13 through a suction filter 4. At the same time water 20 is injected from the air Λ / Vasserabscheider 3 via a line 6 with a water filter 14 and a water cooler 7 in the compressor stage 2. The water cooler 7 is designed as a heat exchanger, via lines 8, 9 normal tap water is added or removed as a cooling medium. Via a further line 10 with a water pump 25 and a fine water filter 26, the water-lubricated bearings of the compressor stage 2 water 20 is supplied from the air / water separator 3, wherein the line 10 is divided just before the compressor stage 2 in two lines 27 and 28.

A mixture of compressed air 13 and water 20 is pressed via a line 5 from the compressor stage 2 in the LufWWaßabscheider 3 and separated there. The compressed air 46 is supplied via a line 12 with a minimum pressure check valve 11 at least one compressed air tank 40.

In the air / water separator 3, the solid particles 18, including the destroyed microorganisms, collected and sediment, the sump formed is periodically discharged through a valve 22. The loaded, drained water 20 is replaced at insufficient water level 21 by lines 24, 33 supplied ultrapure water. This is produced by passing tap water 39 through a valve 32 into a reverse osmosis unit 31, which uses the pressure to reverse a natural osmosis process known per se. The reverse osmosis unit 31 comprises an osmotic membrane which only pours through the carrier liquid and retains the solutes. The membrane must be designed to withstand the pressure of tap water 39. When the pressure of the tap water 39 is greater than the osmotic slope, the contaminant molecules are retained while the ultrapure water passes through the membrane. For the reverse osmosis process to be maintained, the contaminant molecules must be continuously or periodically evacuated and disposed of.

The supply of ultrapure water to the air / water separator 3 is metered via a line 33 with a valve 38 and via a line 24 with a valve 37. A water-permeable dividing wall can be arranged in the air / water separator 3 between the two junctions of the lines 24, 33, whereby the two water tank areas A, B are partially separated.

A regulation of the level 21 of the water 20 in the air / water separator 3 via a water level sensor 30 for the minimum and another water level sensor 29 for the maximum level.

During operation of the compressor unit 1, the humidity of the intake air sucked in via the intake filter 4 is added to the water circuit. When the water level 21 reaches the upper water level sensor 29, the valve 22 opens with sediment to the discharge of contaminated water 20 and closes again in a timed manner. If the water requirement can not be covered by condensed water from the intake outside air 13, ultrapure water is supplied via line 33 and / or 24. In the present case 3 Uitra- sound transmitter 41, 42 are arranged on the left half of the air / water separator. The ultrasonic transmitters 41 arranged at the end dip into the water 20, and the ultrasonic transmitters 42 arranged below the air / water separator 3 can have a shortened design. In the area of the ultrasound transmitters 41, 42, air bubbles 19 are formed in the water, which immediately collapse again and cause the microorganisms and solid particles 18 in the water 20 to destroy rapidly changing pressure differences and local temperature increases. The resulting generated flows in the water 20 cause the smashed solid particles 18, including the destroyed microorganisms, reach the right, quieter half of the air / water separator 3, sediment there and can form a swamp in the bottom layer of the water 20, the as mentioned, is periodically drained and discarded by the opening of the valve 22.

Of course, according to other embodiments of the air / water separator 3, the ultrasonic transmitters 41, 42 may be placed in any desired arrangement. In the compressor stage 2, in the compressed air tank 40, in the water filters 14, 26 in the water cooler 7 and at exposed points of the lines 6, 10 in the water cycle with a tendency to form accumulations of water at a standstill of the compressor stage 2 corresponding ultrasonic transmitter 41, 42 are also arranged, which are only hinted.

All ultrasonic transmitters 41, 42 are electrically connected to a control unit 43. The control unit 43 activates the ultrasonic transmitters 41, 42 individually, in particular during stoppages of the compressor stage 2. An electrical control 34 is connected to all valves of the compressor unit 1 and controls them individually, likewise the control unit 43. For an emergency operation, the valves can also be operated manually ,

In the embodiment of FIG. 2 with vertically arranged compressor stage 2, the per se unchanged, horizontal LufWWaßabscheider 3 is used according to This is sucked in the operation of the compressor system 1 of the compressor stage 2 via the line 5 with a suction filter 4 and compressed. A mixture of compressed air 46 and water 20 is forced via a line 45 from the compressor stage 2 into a cyclone separator 44 and separated there. The compressed air 46 is guided via the line 12 with the minimum pressure check valve 11 to the compressed air tank 40. Not shown, the compressed air 46 can also be performed directly from the minimum pressure check valve 11 to a consumer.

In the cyclone separator 44, a float valve 15 for regulating the level 21 of the water 20 is arranged. The line 6 carries water through the water filter 14 to the compressor stage 2. A nozzle 17 for discharging contaminated water 20 from the cyclone 44 is controlled by the level controller 15, the fresh water is supplied via the water reservoir, which via a water pipe 33 with ultrapure water from the reverse Osmosis unit 31 is supplied. The cyclone separator is equipped with at least one ultrasonic transmitter 42.

In order to further reduce bacterial growth during longer standstill phases or to completely suppress the pressure in the compressor system 1 and thus in the entire water cycle to the minimum pressure check valve 11 can be relieved. The water 20 flows backward through the compressor stage 2 via line 5 in the LufWWaßabscheider 3. All components, which are higher than the air Λ / Vasserabscheider 3, are thereby dehydrated under the action of gravity. Compressed air is supplied from the compressed air tank 40 and from the compressed air network to the minimum pressure check valve 11 of the compressor stage 2 via a line 36 after the opening of valve 35. This compressed air, which in this case has been relieved from a pressure of 8 bar to normal pressure, generally has a relative humidity of less than about 15%. This dry purging air pushes the remaining water in the water cycle in the air / water separator 3 or in the Cyclone 44 and dries for the most part the compressor stage 2 and the lines. If the compressor unit 1 is still followed by an unillustrated dryer, the line 36 can also be connected to the dryer, so is still dry purging air available. It is known that microorganisms developed in water do not survive in a dry atmosphere.

The water treated in an air / water separator 3 of a compressor installation 1 can be supplied via another, not shown in FIGS. 1 and 2 line another, any intended use, if it is not or only partially consumed by the compressor stage 2. With appropriate dimensioning can be achieved by sonication with ultrasonic waves of industrial water / drinking water that particular microorganisms such as bacteria, viruses, germs, are wholly or largely killed. This prevents people and / or animals using the water from becoming infected and possibly ill.

Claims

claims

1. A method for regenerating internal water circuits of a compressor unit (1) for generating compressed air (46), which compressor unit (1) essentially comprises at least one compressor stage (2) cooled by injected water and lubricated,

characterized in that

at least one electronically controlled ultrasonic transmitter (41, 42) emits ultrasonic waves in water accumulations in the compressor system (1).

2. The method according to claim 1, characterized in that with the emitted ultrasonic waves microorganisms, in particular bacteria and / or germs killed, smashed solid particles (18), deposits are removed in the water circuits and / or the water is vented.

3. The method according to claim 1 or 2, characterized in that at equal or different time intervals during the same or different time periods ultrasonic waves are emitted in water accumulations.

4. The method according to any one of claims 1 to 3, characterized in that the Uitraschallwellen be sent out when the compressor stage 2.

5. The method according to any one of claims 1 to characterized in that ultrasonic waves in the range of 20 to 35 kMh, in particular 23 to 25 kHz, are emitted.

6. The method according to any one of claims 1 to 5, characterized in that the ultrasonic waves in compressor stages (2), in air / Wasserab- scheidem (3), in Zyklonabscheidern (44), in water coolers (7), in water filters (14 , 26), in compressed air tanks (40) and / or in water pipes (6, 10) are generated.

7. The method according to any one of claims 1 to 6, characterized in that the destroyed microorganisms and crushed solid particles (18) sedimented in the LufWWaßabscheider 3 and / or in Zyk- Iσnabscheider (44) are discharged as a swamp and disposed of.

8. The method according to any one of claims 1 to 7, characterized in that at a standstill at least part of the compressor system (1), this preferably automatically drained and flushed with compressed air (46) from the compressed air tank (40) and dried.

9. compressor system (1) for carrying out the method according to one of claims 1 to 8, which essentially at least one each by injected water cooled and lubricated compressor stage (2) with water coolers (7) and water filters (14, 26) and at least one air Comprises / water separator (3),

characterized in that

in the compressor stages (2), in the air / water separators (3), in the cyclone separators (44), in the water coolers (7), in the water filters (14, 26) and / or in the water pipes (6, 10) Ultrasonic transmitters (41, 42) are arranged.

10. compressor system (1) according to claim 9, characterized in that it comprises at least one pressure vessel (40) each having at least one ultra shell (41, 42).

11. compressor system (1) according to claim 9 or 10, characterized in that for the air ~ / water separation a cyclone separator (44), preferably with at least one ultrasonic sensor (42) is arranged.

12. Application of the method according to one of claims 1 to 8 in the food and beverage industry, pharmacy, healthcare, electronics and textile industry.