WO2015178818A1

WO2015178818A1 - Proceeding for flushing of pipes at hydraulic systems and a plant for the flushing

Info

Publication number: WO2015178818A1
Application number: PCT/SE2015/050402
Authority: WO
Inventors: Tobias AHLBERG; Karl-Johan STJÄRNA
Original assignee: Tts Marine Ab
Priority date: 2014-05-23
Filing date: 2015-03-31
Publication date: 2015-11-26
Also published as: SE538171C2; CN106573278B; CN106573278A; KR20170012291A; SE1450616A1; KR102376608B1

Abstract

The invention concerns a proceeding for the pipe flushing of a hydraulic system (3) internally by throughput of said hydraulic system (3) with fluid (4) in a flow of at least Re 2300 Reynolds. According to the invention, motor (5), pump (6) included in utilized plant (2) and the desired purification degree are regulated by a control unit (1) by the feedback of motor speed, oil flow, oil temperature, and contamination degree via particle counter (23). In that connection, there is provided automatic purification of the oil (4) or of another fluid, which is utilized in a so-called closed loop system with corrections automatically made by the control unit (1) after predetermined desired final result of the purification degree before approved result report can be delivered. The invention also concerns a plant (2) for accomplishing a said proceeding.

Description

Proceeding for flushing of pipes at hydraulic systems and a plant for the flushing.

The present invention concerns a

proceeding for pipe flushing of a hydraulic system

internally by throughput of said hydraulic system with fluid in a flow of at least Re 2300 Reynolds.

Flushing of pipes, i.e., cleaning of a hydraulic system internally according to known proceedings in connection with a fluid in a turbulent flow of at least Re 3000, takes place, inter alia, in such a way that the contamination degree of the fluid is measured by, among other things, particle counter according to ISO 4406:1999 or NAS 1648 or by other known similar proceedings. In pipe systems for hydraulic plants, there are problems to reliably and efficiently be able to get all parts of the ship in serviceable state in a short time and with good results .

Since the entry of modern hydraulics in

1970's-80's, it has globally been proved to be very problematic to accomplish a correct flushing. This

manifests itself in the form of hydraulic breakdowns, leaky seals, damaged and fixed valves, etc., which brings about high repair costs and disappointed customers

entailing decreased supplier confidence.

On board, e.g., ships, before delivery of ready-built and installed ship, it is necessary to clean all hydraulically controlled ramps, gates, car decks, and doors and which have at least double pipe sections. In that connection, each pipe section has to be coupled to and from the flushing station in question to undergo the intended cleaning. Totally, there may be more than several tens and hundreds of individual flushings for each ship, which may require over a month. Thus, this justifies an automatization .

The principal reason is to a major degree the generally insufficient knowledge within the technical field of flushing together with the importance so often minimized of a clean system. Likewise, it is shown how difficult and expensive it actually is to take care of a contaminated system afterwards, if it at all is possible without complete component replacements.

It is also important that the operator who carries out the work has access to a station having capacity enough to deliver the requisite flow. Exactly this has turned out highly distressing since ever so few users manage to dimension which motor and pump, etc. that are required to execute a flushing complying with at least Re 3000. Re 3000 is the internationally recognized feed flow for the purpose but also Re 4000 is found.

To verify the capacity of an existing station, calculation skills within hydraulics are also required, which the practician most often does not possesses or can be required to know.

The above-mentioned is an international problem that continuously affects the large OEM

manuf cturers within, for instance, the offshore & marine industry.

Therefore, the main object of the present invention is primarily to solve, among other things, the above-mentioned problems, and provide shorter flushing periods, automatized flushing, and automatic logging of obtained values in contrast to today's manual proceeding.

Said object is achieved by means of a proceeding according to the present invention, which essentially is characterized in that, by a control unit, which regulates motor, pump included in the utilized plant and desired purification degree by the feedback of motor speed, oil flow, and oil temperature, there is provided automatic purification of the pipes in a so-called closed loop system by corrections automatically made by the control unit to maintain at least predetermined value of Re Reynolds number after predetermined desired final result of the purification degree, before approved result report is delivered.

The invention also concerns a plant for accomplishing a proceeding of the above-mentioned kind in a reliable, good, and cost-effective way.

A said plant is characterized, among other things, in that the control unit included in the plant comprises means allowing controlling motor, pump included in said plant and desired purification degree, that said control unit is arranged to receive values from feedback of motor speed, oil flow, and oil temperature, and that said control unit is arranged to provide automatic

purification of the oil in a so-called closed loop system, the control unit comprising means allowing making

automatic corrections of the plant after predetermined desired final result of the purification degree, before approved result report is delivered.

According to the present invention, the knowledge concerning the flushing is now moved from the operators to a control unit for accomplishing said

proceeding for the flushing of pipes and to a plant for accomplishing a said proceeding according to the

invention. Said control unit may consist of software utilized in a computer and according to the invention, intended purification of the pipes is provided by means of oil or another fluid in a so-called closed loop system in contrast to previously utilized "open loop systems" .

According to the invention, the knowledge is now moved from the practician to the software and affords a very simple user interface 14.

The software uses a number of mathematical formulas to regulate the outflow of the pumps so that at least Re 3000 or 4000 feed flow always is delivered regardless of the fluid temperature and pipe size at the same time as built-in functions guarantee that desired purity always has been attained before approved result report can be delivered. Thus, a fully automatic flushing station is provided.

A traditional flushing system operates according to the principle open loop system, which means that the system does. not process fed back parameters and accordingly cannot take rectifying measures to achieve a predetermined result .

Traditional systems do not process fed back parameters or lack, in certain cases, entirely feedback from the system and cannot accordingly guarantee that correct conditions upon flushing apply in a given pipe system.

Usually, an electric motor is run at about 1500 V/min, which in turn drives a fixed or pressure- compensated pump .

This traditional method has, among other things, the disadvantages mentioned below:

* No feedback to the system indicating if the flushing is OK or not.

* Generates much heat, which normally simultaneously has to be cooled away. * Requires large electric motor and/or pump to carry out the desired operation.

* Large plant dimension to manage the job.

* The operator himself/herself has to monitor the flushing and take active measures to keep Re 3000.

* Very high operation noise.

* No possibility of logging, for instance, flow, pressure, temp., ISO/NAS code, since this is

necessary to document manually. In the best case, it is possible to dump the particle counter of information but this then shows only the contamination degree and not the simultaneous oil flow, which could have proven that the pipes are clean and not only the oil .

* Tremendously time-consuming logging operation.

* Very simple for the operator to create a misleading and positive report that then may be used against OEM to disclaim possible warranty problems.

* Expensive to construct since everything becomes large and soon escalates economically.

* High running costs .

* In traditional flushing, oil temperature has been the factor that the operator in the best case has been able to manipulate in order to increase the pipe length during cleaning in progress or to reach the desired Reynolds number. This is often not enough and pump station replacement therefore becomes the solution.

* Requires traditionally a plurality of external expensive instruments to carry out the operation.

According to the present invention, it is now proceeded according to "closed loop system", which means that the proceeding and system in question according to the invention have feedback from the final result and which allows to let the software or another entered information in a control unit 1 in question to take intended rectifying, corrected, measures to achieve the predetermined result desired to be achieved.

According to the invention, the following advantages, among other things, are now achieved:

* Feedback to software which also is shown to operator in touch panel/user interface.

* Generates only the frictional heat that the oil flow produces. This applies all through the pipe register.

* Smaller electric motor and pump

required, since now it is possible to run at speeds up to 3700 revolutions per minute.

* Is given considerably smaller plant dimension and which allows move by palletiser. Increases the mobility with a considerably more compact design compared with known plants on the market and which have the same or higher power. Dimension and weight now allow, among other things, air transport.

* The operator does not have to make any adjustments of the equipment since the software handles the flushing.

* Ever so low operation noise thanks to special pumps are utilized, e.g. vane pumps, and by well thought-out tank design.

* Logs all flushings and shows the results in user interface where it is possible to see how the oil goes from dirty oil to clean oil. Upon printout, all required data are received with unique identity number indicating, among other things, date, time, pipe

dimension, and name, etc.

* The result history is saved in user interface and may simply be transferred to, e.g.,

Flash/USB memory.

* Is not possible to tamper with the results and no approved result is received if the flow is too low. Thus, it is prevented that only the oil is clean but the pipes dirty, which is so frequent today.

* Economically advantageous alternative, by fewer and more inexpensive components.

* Low running costs in relation to

traditional technique thanks to lower power consumption.

* Viscosimeter may be present, wherein the plant upon flushing can be extended to be used for other fluids and purposes than hydraulic systems.

The invention is described below,

reference being made to the accompanying drawings in which,

Fig. 1 shows a schematic cross-section of a plant according to the invention, and

Fig. 2 shows a block diagram of the plant and the proceeding utilized thereby.

A proceeding for accomplishing so-called flushing of pipes at hydraulic systems 3 internally by providing throughput of said hydraulic system 3 with fluid 4 in a flow of at least Re 2300 (Reynolds) is accomplished according to the present invention in such a way that there is provided automatic purification of the hydraulic pipes by means of the oil 4 or another suitable fluid utilized therefor in a so-called closed loop system. By selected pipe size in user interface 14 and by means of a control unit 1, which regulates motor 5, pump 6 included in a utilized plant 2 and the desired purification degree, feedback is provided of rotational speed of the motor 6 or motors 6 in question, turbulent oil flow, and oil

temperature .

The invention according to "closed loop" comprises the steps indicated below.

I. The operator selects pipe size in user interface 14.

II. By selection of pipe size, the control unit 1 regulates motor 5 and pump 6.

III. Temperature sensor, particle counter 23, the oil flow from frequency converters 17 are fed back to the control unit 1.

IV. The control unit 1 processes the

parameters in said point III and regulates heater element 16, frequency converters 17 and cooling fan 25 to maintain at least Re 2300.

V. When the desired degree of purity of fluid, and accordingly then also of the hydraulic pipes, an approved report is presented in the user interface 14.

In that connection, intended corrections of said flushing of pipes are carried out automatically by the control unit 1 after predetermined desired final result of the purification degree. In that connection, feedback is provided of obtained measured values to a software or any other suitable control means in said control unit 1 and which in turn controls so that the desired parameters are achieved automatically in a plant 2 in question, before approved result report is delivered. That is, without involving any persons and manual

adjustment. Suitably, the flushings in question are logged so that the purification procedure can be monitored from start to end and with possibility of providing reliable extraction of desired data from the plant 2 if desired and need therefor. For example, a unique number may show, among other things, date, time, pipe dimension, location, name, etc. Obtained results are arranged to be possible to be saved in, e.g., an internal memory in the plant 2 or in another way and be possible to be extracted via, e.g., USB memory or to another extractor. For instance, it is possible to make screen dumps to mail over to a central for, e.g., technical support.

In said software or in another control means, a number of mathematical formulas are used to correctly be able to regulate that the outflow of the pumps in question is the correct one desired as well as to ensure so that correct feed flow always is provided and that the final result of the purification is checked before the approval of the purification is given. In that connection, it is arranged so that the approval result of the purification is allowed to be given only when the flow through the pipes 3A achieves a certain determined smallest flow value. Naturally provided that the rest of the necessary parameters for the purification also have been attained. Before start, dimension is entered by the user interface 14 of the pipes 3A utilized in the

hydraulic system 3 intended to be checked.

In that connection, e.g., a green flashing light may communicate that completed programme is

approved-. Furthermore, a red flashing light may

communicate plant error and then immediately stops the machine, and indicates a specific alarm in the user interface 14.

* Saved logging curves can be studied directly in user interface. * The user can determine the filename of the log file, which is saved in internal memory.

* Direction of rotation of electric motors becomes correct independently of phasing.

* All the motors are protected against overload.

* Emergency stop is available locally and with possibility of remote stop via cable.

* Built-in function may exist for

filling/emptying of tank, with power feedback function which senses if, for instance, an oil barrel is empty to protect against the pump running dry.

* A plurality of return filters may be present with selector to continue to operate without stop for filter change.

* Boost Flush may be arranged to be possible to be carried out, i.e., a state that is

activated by the operator and where the plant is given full power, i.e., more than what is needed to provide maximum flow in pipes for a shorter time. Said "Boost

Flush" is utilized when it is suspected that an extra high contamination degree of hydraulic system is at hand.

A plant 2, which is arranged for

accomplishing a proceeding of the above-mentioned kind to provide flushing of pipes at hydraulic systems 3

internally by providing throughput of said hydraulic system with fluid in a flow of at least Re 2300

(Reynolds) , comprises an intended control unit 1 having means included therein allowing controlling, among other things, included motor 5, pump 6, and the desired

purification degree. Said control unit 1 is, in that connection, arranged to receive values from feedback of motor speed, contamination degree, oil flow, and oil temperature from means sensing the same. The control unit 1 is furthermore arranged to provide that automatic purification of the oil is carried out in a closed loop system and comprises means allowing making automatic corrections of the plant 2 after predetermined desired final result of the purification degree of the cleaned oil in the intended connected hydraulic system 3 and the lines 3A thereof, before approved result report is delivered.

In the control unit 1, there is included software or another control means, which is arranged to control so that the desired parameters are achieved.

Units included in said plant 2 are

contained in a compact stand 8 having a covering cap 9 externally thereon and is suitable to be handled by means of, e.g., one or more fork-lift trucks or by other

suitable lift and/or transportation means, e.g. palletiser or crane. Furthermore, there is a tank 10 for the receipt of fluid in the bottom of the plant 2 and having driving and control units therefor situated on top of and/or on the side of the tank 10.

Couplings 11 for the pressure and return hoses 12, 13 for checked fluid 4 are connected to the plant 2. In the plant 2, such as for instance is shown in Fig. 1, there is included user interface 14 having touch panel for the adjustment of the desired functions, obtained results, and for the extraction by printing and/or data of obtained results and/or for the input of files to control program of the plant 2. Furthermore, means is included for the selection of filter 15. The control unit 1 allows to alarm upon dirty filter 15 and selection of pump(s) 6, motor(s) 5, filling level of the oil 4 in the tank 10, heater element 16 for the heating of the oil 4 in the tank 10, cooling fan 24 for the cooling of the oil 4 in the tank 10, and control for start and stop. Also a number of frequency converters 17 for the motors 5, e.g. vane pumps 6 and a plurality of separated systems for pipe wash, pressure test, and hydraulic control are included in the plant 2. Means for the logging of flow of fluid, pressure transducer 25, temperature 18, time, viscosity, flushing time, particle counter status, number of approved measurements, oil level, etc., are included in a said programme for pipe wash.

In a programme for the pressure test of pipes, means are included for the logging of pressure, pressure curve, and display of the same, and in a

programme for hydraulics proceeding, there are included means for operating hydraulic equipment and means for selecting maximum hydraulic pressure -and maximum flow of the fluid. Also means for providing standby heating of the oil and misconnection means to protect staff and plant against misconnection, etc., in the plant 2 are included therein.

* Maximum pressure is 420 bar at pressure test .

* Ramps up the pressure to avoid pressure surges .

* Automatically releases the pressure in case a pipe would burst during pressure test or filling phase .

- * Simple to select the desired pressure in user interface 14.

* Logs the pressure curve and displays it with, e.g., 60 min history. Software, etc., for the plant 2 comprises descriptive pages for the operation of the plant 2 and information about parts therein, such as filter type, service points, etc., in user interface 14.

The nature and function of the plant 2 should now have been clearly understood with the aid of the above-mentioned and shown in the drawings. A said plant 2, which is compact and relatively light, for instance empty it weighs slightly more than 1 ton and the double with a full tank 10, has the dimensions about 1,8 x 1,25 x 1,6 m.

Upon start-up of the proceeding after connection of the hydraulic system 3 to the plant 2 in a loop via the connections 11, first the oil 4 is heated to the correct temperature in the tank 10 and standby heat may be presentin the system to minimize heating time at low temperatures, for instance in the winter. When running the oil 4 is measured via electric cable 19, 19A, by means of the particle counter 23, it is possible to easily see how the purity values of the oil are changed and the result can be read in diagram in user interface 14. Data are automatically stored in the plant and can be extracted via USB memory or in another desirable way. Returned scavenge oil is directed via a filter 15 to the tank 10 via pipe 20. During cleaning of the system 3, the cleaned oil is directed out to the system 3 again via outgoing pipe 21 and which pipes 20, 21 are included in said

"closed loop system" .

* Washes pipe according to Re 2300, 3000, & 4000.

* The maximum flow is 322 1/min. * Manages at least pipe diameters between 8-70 mm, which is the most common dimensions within the hydraulics but also greater pipe diameters.

* The software provides for the flushing and ensures that feed flow always is Re 2300, 3000, or alternatively 4000, or Boost Flush.

* If the flow should not be sufficient, because of external factors, there are built-in functions of the software with complete solutions so that the operator only faces very simple selections and can

continue the operation.

* Quick flushing by good filter

technology .

* Possibility of selecting between Re 2300, 3000, and 4000, as well as Boost Flush.

* .Possibility of monitoring oil

viscosities .

* Logs flow, pressure, temperature, time, viscosity (theoretical) , flushing time, particle counter status, number of approved measurements, oil level, loop number, etc.

* Upon oil colder than 5 °C, the station gives 50 1/min to protect the pumps against cavitation. When oil has risen to operating temperature (>5 °C) , the system returns to normal operation.

Upon pressure testing of the system 3 and its pipes included therein, test can be made all the way up to about 420 bar. When the oil 4 becomes too warm, cooling fans 24 start to run and cool the oil 4.

A hydraulic system may be driven by the plant if required. The maximum pressure is 250 bar and the maximum flow is 80 1/min. There is naturally safety equipment in the plant 2 to automatically act upon abnormal operation, such as if an oil pipe would burst, upon misconnections , or upon faulty controls, etc. The plant 2 is arranged to manage to clean pipes having a greater diameter than 8 mm, but at least the most common pipe dimensions used on ships, which are of between 8-70 mm in diameter, pressure testing installed pipe system at 50-420 bar, and be used as traditional pump station and thereby provide for most hydraulic needs present within, e.g., offshore- and marine production industry with superior performance and

usability in relation to known traditional systems

therefor .

1. Control unit

2. plant

3. hydraulic system

4. fluid (oil)

5. motor

6. pump (vane pumps)

7. closed loop system

8. stand

9. cap

10. tank

11. couplings

12. Pressure and return hoses

13. _ II _

14. touch panel/user interface

15. filter

16. heater element

17. frequency converter

18. temperature

19. S 19A. electric cable for oil tank

20. incoming pipe conduit 21. outgoing pipe conduit

22. electric cable for particle counter

23. particle counter

24. oil cooler

25. pressure sensor

Function and nature of the invention should have been clearly understood from the above- mentioned and with knowledge also about what is shown in the drawings but the invention is naturally not limited to the embodiments described above and shown in the

accompanying drawings. Modifications are feasible, particularly as for the nature of the different parts, or by using an equivalent technique, without departing from the protection area of the invention, such as it is defined in the claims.

Claims

C l a i m s

1. Proceeding for the pipe flushing of a hydraulic system (3) internally by throughput of said hydraulic system (3) with fluid (4) in a flow of at least Re 2300 Reynolds, characterized in that, by a control unit (1), which regulates motor (5), pump (6) included in utilized plant (2) and the desired purification degree by the feedback of motor speed, oil flow, oil purification degree, and oil temperature, there is provided automatic purification of pipes (3) by means of oil (4) or by another fluid, which is utilized in a so-called closed loop system (7) with corrections automatically made by the control unit (1) to maintain at least predetermined value of Re Reynolds number after predetermined desired final result of the purification degree, before approved result report can be delivered in user interface (14) .

2. Proceeding according to claim 1,

characterized in that feedback is provided of measured values to software or another control means in said control unit (1) and which in turn controls that the desired parameters are automatically achieved in a plant (2) in question.

3. Proceeding according to claim 2,

characterized in that the pipe flushing in question is logged in user interface (14) so that the purification procedure can be monitored from start to stop and with the possibility of reliable extraction of desired data from the plant (2) , such as a unique number showing, among other things, date, time, pipe dimension, name degree of purity (ISO/NAS) , the temperature of the oil, flow,

Reynolds number, contamination curve, flow curve, for selected pipe dimension, and that obtained results are saved in internal memory in user interface (14) .

4. Proceeding according to any one of claims

2-3, characterized in that, in the software, a number of mathematical formulas are used to regulate that the outflow of the pumps is the correct one desired as well as that correct feed flow always is provided and that the final result of the purification is checked before the approval of the purification is given.

5. Proceeding according to claim 4,

characterized in that approval of result of the

purification is arranged to be given only when the flow through the pipes (3) simultaneously achieves a certain determined smallest flow value.

6. Plant (2) for accomplishing the proceeding according to any one of the above claims for the pipe flushing of a hydraulic system (3) internally by

throughput of said hydraulic system with fluid in a flow of at least Re 2300 (Reynolds) , characterized in that the control unit (1) included in the plant comprises means allowing controlling motor (5) , pump (6) included in said plant and the desired purification degree, that said control unit (1) is arranged to receive values from feedback of motor speed, oil flow, oil purification degree, and oil temperature, and that said control unit (1) is arranged to provide automatic purification of pipes (3) by means of oil (4) or by another fluid, which is utilized in a closed loop system (7) , the control unit (1) comprising means allowing making automatic corrections of the plant (2) after predetermined desired final result of the purification degree, before approved result report can be delivered in user interface (14) .

7. Plant (2) according to claim 6,

characterized in that, in the control unit (1), there is included software or another control means to control that the desired parameters are achieved.

8. Plant (2) according to any one of claims 6-7, characterized in that units included in the plant are contained in a compact stand (8) having a cap (9)

externally and suitable to be handled by, for instance, one or more fork-lift trucks, crane, or palletiser, and having a tank (10) for fluid in the bottom and driving and control unit on top of or beside the tank (10) .

9. Plant (2) according to claim 8,

characterized in that couplings (11) for pressure and return hoses (12, 13) for controlled fluid are connected to the plant (2 ) .

10. Plant (2) according to any one of claims 6-9, characterized in that a user interface (14), e.g. touch panel, for the adjustment of the desired functions, for obtaining results, and for the extraction by printing and/or data of obtained results and/or for the input of files to control program in the plant (2) , is included in the plant (2) .

11. Plant (2) according to any one of claims 6-10, characterized in that means, for the selection of filter (15) , pump (6) , motor (5) , filling level, oil temperature, heater element (16) for the heating of oil (4) , cooling fan (24) for the cooling of oil (4), and having control for start and stop, is connected to the plant (2) .

12. Plant (2) according to any one of claims 6-11, characterized in that frequency converters (17) for motors (5) , vane pumps (6) , and a plurality of separated systems for pipe wash, pressure test, and hydraulic operation are included in the plant (2) .

13. Plant (2) according to any one of claims

6-12, characterized in that means for the logging of obtained values for flow (25) , pressure, temperature (18) , time, viscosity, cleaning time, particle counter status (23) , number of approved measurements, oil level, degree of purity (ISO/NAS) , the temperature of the oil, flow, Re Reynolds number, contamination curve, flow curve for selected pipe dimension, etc., in user interface (14) are included in a programme for pipe wash.

14. Plant (2) according to any one of claims

6-12, characterized in that means for the logging of pressure, pressure curve, and display of the same is included in a programme for the pressure test of pipes.

15. Plant (2) according to any one of claims

6-12, characterized in that means for operating hydraulic equipment and means for selecting maximum hydraulic pressure and maximum flow are included in a programme for hydraulic proceeding.

16. Plant (2) according to any one of claims 6-15, characterized in that means for providing standby heating and standby cooling of the oil (4) , misconnection means to protect staff and the plant (2) against

misconnection, etc., are included in the plant (2) .

17. Plant (2) according to any one of claims

6-16, characterized in that software, etc., comprises descriptive pages for the operation of the plant (2) and information about parts therein, such as filter type, service points, etc., in a user interface (14) .