DE102012003639A1 - Method for operating a high-pressure cleaner with different operating modes - Google Patents

Abstract

A method of operating a high performance HD cleaner having at least one high pressure pump driven by a prime mover, wherein the water drawn in from the upstream side of the HP pump is compressed and conveyed through a heated boiler, and at least one spray lance is discharged, wherein the drive motor is controlled in its speed.

Description

The invention relates to a method for operating an HD cleaner with different operating modes, as well as an HD cleaner designed according to the method.

It is known to provide different operating modes of an HD cleaner, in particular it is known to operate an HD cleaner in the frost protection mode, as well as in steam operation and in excess operation.

1. State of the art for frost protection operation

Under the operating mode "frost operation" is understood that it is known in the art, when falling below the outside temperature to frost temperature to protect the freezing of the HD cleaner antifreeze operation such that at such low temperatures, if the HD-cleaner not. In working mode, only a small amount of water passes through the HD cleaner to prevent freezing of the internal and external lines.

For this purpose, the DE 2541383 A1 that when reaching a certain frost temperature, the drive motor of the high pressure pump is briefly turned on and off again to achieve a water flow for a relatively short time and thereby avoid water in the housing (both in the low pressure and the high pressure branch) stops and freezes there.

An identical object results, for example, from the DE 3 817 432 A1 or the DE 1 672 216 B1 ,

In the mentioned method for operating the high-pressure cleaner in the antifreeze operation, however, has the disadvantage that the pumped by the high-pressure pump water quantity is unnecessarily high due to the short-term switching on the engine, because the HP pump briefly runs in normal operation and thus wasting the water in an unnecessary way becomes. Through this short-term full load operation, the water is conveyed through the low and high pressure branch, which is associated with high water consumption costs.

There is thus further the danger that the user erroneously uses such a high-pressure cleaner, which actually works for a short time in frost protection mode, for the intended use (eg for car washing), although the mode of operation is not set up for this purpose. Namely, the HD cleaner turns off after the predetermined time and is not turned on by the user, resulting in complaints.

Further, it is known to use to protect against freezing of a high-pressure cleaner running parallel to the high-pressure pump, smaller feed pump which removes water in the low-pressure water supply and promotes low pressure and low flow in the high-pressure branch, so as to protect the high-pressure branch against freezing ,

Disadvantage of this arrangement, however, is that for this purpose a separate pump must be used and that the connection of this parallel pump branch is connected to the high-pressure branch with relatively great effort, namely with the use of overflow and check valves.

If such valves wear or do not function properly, there is an undesirable return of high pressure water into the parallel branch of the antifreeze pump, which is associated with destruction of the antifreeze pump.

In addition, there is the disadvantage in the impulssweise switching a high-pressure pump for the purpose of frost protection, the disadvantage that the cold engine and pump bearings are highly stressed, but have not built up an oil film, because low temperatures exist. Therefore, with high wear, the additional risk of bearing damage and damage to the sealing rings and other sealing between the rotating and fixed components.

2. State of the art for steam operation

There is another operating state of a high-pressure cleaner known, which relates to the so-called steam operation.

In such a steam operation is in the foreground that from the high pressure nozzle of the spray lance no water should be delivered, but a steam jet, which consists of superheated steam. Here, it is known to limit the delivery of the high-pressure pump in that the high-pressure pump is bypassed by a bypass branch, which means that a certain amount of water is fed back to the water inlet from the high-pressure branch via an adjustable control valve, so that the high-pressure pump with full liquid performance promotes, but on the other side of the branch valve, a small amount of liquid in the boiler and in the high-pressure branch is conveyed, whereby the water is heated in the boiler at steam level and then in the form of a superheated steam is discharged from the high-pressure gun.

However, the control of the bypass valve for returning an amount of water to the inlet side of the high-pressure pump is difficult. As a rule, this is carried out by hand and under visual control of the steam jet emerging from the high-pressure nozzle, the three-way valve is adjusted so that the amount of water reaching the boiler is so low that steam is formed there by overheating the amount of water still flowing at a low volume.

This is a high Einstellaufwand and is dependent on the ambient temperature, so that the setting and operation of such a steam stage is possible only under optical control and manual adjustment of the three-way valve.

3. State of the art for surplus operation

The third operating mode of an HP cleaner is the so-called surplus operation, which means that according to the prior art, the high-pressure pump operates with the same flow rate, but the valve arranged on the spray lance is designed as an excess valve. This means that the lance-side spray nozzle designed for maximum passage delivers a large amount of water with a lower water temperature. Such a mode is used for flushing cleaning surfaces.

Disadvantage of this arrangement is that when a water jet with high volume and low temperature is desired, the boiler working at full load must be on and off in pulses, which is associated with increased wear of the boiler and the unwanted emission of larger amounts of exhaust gas.

The invention is therefore based on the object, a method for operating an HD cleaner with different modes and an operating according to the method HD-cleaner so that with significantly lower means the various modes described are easily adjustable.

To solve the problem, the invention is characterized by the technical teaching of claim 1.

It is essential that the drive motor of the HP pump is speed-controlled. Such a variable-speed drive motor copes in a surprising manner all three aforementioned modes with little effort and simple means. It follows that the method for operating the variable speed drive motor and the operating according to the method drive motor for all three Betriebarten can be used in an optimal way. The speed-controlled drive motor is thus the unity of the invention producing connecting, functional "band". Thus, the invention is uniform, because the inventive idea of the speed control of the drive motor can be used in the form of various operating modes of the HD-cleaner.

The focus of the invention is therefore a drive motor whose speed is designed to be controllable by electrical means. Such, adjustable in its speed motor is preferably a three-phase asynchronous motor. In an alternative embodiment, a three-phase synchronous machine or a DC-operated slip ring motor can be used, although its circuit complexity is greater.

The AC motor (also called induction motor) is an electric motor that is operated with single-phase alternating current. A preferred alternative is the operation of a three-phase motor with a frequency converter, which rectifies the AC voltage and then converts it into three-phase current. With such a three-phase motor speed adjustment in wide ranges is possible. For this reason, this embodiment will be described in more detail below, but this is not intended to limit the scope of the invention.

Frost protection mode

An essential feature with respect to the operating mode antifreeze operation is that a three-phase motor, which drives the HP pump is controlled by a frequency converter, which is able to control the speed of the three-phase motor from the actual operating speed of z. B. 3000 U / min on z. B. 2 revs / min.

With the given technical teaching, there is the advantage that a frost protection operation can be driven, which is that upon reaching a certain temperature of weathering of z. B. 0 ° C, the rotational speed of the three-phase motor is adjusted by suitable control of the frequency converter so that the high-pressure pump and the three-phase motor z. B. run only with a minimum speed 2 U / min for the entire operating life of the frost protection operation.

This means that for the anti-freeze operation, the speed of the three-phase motor and thus the flow rate of the HP pump is significantly reduced and a continuous, continuous flow of water through the low-pressure and high-pressure branch runs. This has the advantage that a constant flow through all wetted parts of the high-pressure cleaner, so that all wetted parts are reliably protected from freezing.

Furthermore, there is the advantage that due to the greatly reduced speed of the HP pump, a barely perceptible engine and pump noise is generated and no longer the previously given by the prior art impulsively switching on and off must be accepted, with full load was switched to rest and vice versa. Thus, such a frost protection operation is gentle on the engine parts used, because the high-pressure pump is constantly driven at a low speed, and thus all remain evenly lubricated with oil-lubricated bearings. Likewise, all seals remain evenly moistened and do not dry out, as could occur in the prior art.

Speed-controlled drive motor

Important in all modes is therefore that the three-phase motor of the HP pump is speed-controlled and according to the selected mode within wide limits above or below its dependent on the mains frequency speed is adjustable.

For a speed control, a frequency converter is preferably used and - if it is an asynchronous - three-phase motor, the speed control is done simply by the fact that in the frequency converter at a standard frequency of 50 Hz is sometimes controlled to a lower frequency converter of z. B. 2 Hz or according to the selected operating state of the HD-cleaner also to a value of> 50 Hz.

The invention thus relates to the combination of all three types of operation, but also claimed each individual mode of operation as essential to the invention and in isolation.

steam operation

As a further mode of operation of the so-called steam operation is specified, which was the prior art in that the high-pressure pump was bridged by a bypass branch, wherein a secondary flow was fed back from the high pressure branch back to the water inlet of the high pressure pump.

The invention can dispense with this because it is provided according to the invention that the rotational speed of the three-phase motor and thus the delivery of the high-pressure pump is lowered by the setting of the frequency converter, so that this high-pressure pump delivers less capacity to the boiler and the boiler but operated with the same thermal performance as in normal operation, so that the water flowing through the boiler (which corresponds to a low flow rate) z. B. is heated to a temperature of 140 ° C.

The heating of the water can be detected by a arranged in the HD branch temperature sensor and if z. B. a water temperature of 140 ° C to be adjusted, the temperature sensor signals via an associated signal line its signal to a microprocessor whose output is connected to the frequency converter, so that the frequency always reduces the high-pressure pump to such a speed and ensures that always a water temperature of z. B. 140 ° C at the outlet of the boiler is achieved.

Excess operating

The third mode of operation according to the invention is the so-called surplus operation.

The surplus operation is characterized in that the speed control of the high-pressure pump is designed so that the three-phase motor is driven at more than 50 Hz, z. B. with a frequency of 200 Hz, whereby its speed is quadrupled, for example. Thus, the delivery rate of the HP pump is increased and it is envisaged that the resulting water flow is discharged with a larger volume through a large-sized lance-side nozzle as excess water, whereby the delivery of a large amount of water from the water lance at low temperature is possible.

When washing agricultural animals, such. As pigs or cows, it is preferred if the amount of water at the outlet of the high-pressure lance for washing and rinsing of the animal body is increased, but the temperature is set, for example, only on a temperature range of 50 ° C, creating a particularly gentle and pleasant cleaning of the animals given is.

Thanks to the operation with a frequency converter, therefore, the water is always conveyed with constant volume in the working with the same thermal capacity boiler, without the need for pulse-wise switching on and off of the boiler, as is the case in the prior art.

In the prior art, a so-called hysteresis had to be accepted, which means that when the boiler is turned on and off in pulses, it takes a few seconds to the water can be delivered in the required temperature at the high pressure lance.

This avoids the invention, because the invention provides that the boiler always always works with its maximum thermal power, which significantly increases its life and the emission of harmful exhaust gases, because a pulse-wise operation is avoided and what a hysteresis-free delivery of a large volume flow of Low temperature water can be used.

The invention also provides that of a large-volume (rinsing) nozzle, the large-volume water jet with z. B. 50 ° C, can be switched to a low-volume nozzle (high pressure nozzle), which then correspondingly with a temperature of z. B. 99 ° C releases.

It is therefore a switch between a nozzle emitting a large volume jet and a lower volume jet emitting nozzle in excess operation.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following, the invention will be explained in more detail with reference to drawings illustrating several execution paths. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Show it:

1 : Schematically illustrates a high-pressure cleaner according to the invention for the frost protection operation

2 : a diagram of the speed control for the anti-freeze operation of the HD cleaner after 1

3 : a high pressure cleaner after 1 for steam operation

4 : a high pressure cleaner according to the 1 and 3 for the surplus operation

In figures, the same parts are provided with the same reference numerals, therefore, the same explanations apply to all three drawings and the parts shown there.

In 1 is shown that a three-phase motor 1 from a frequency converter 18 is controlled, at the three-phase input 19 the three-phase current sourced from the mains is applied.

The three-phase motor 1 drives a high-pressure pump via its mechanical shaft 2 on, the water from a low-pressure water inlet 3 sucks, to a pressure of z. B. 100 bar and in the HD stage 4 emits.

The water flows into the boiler 5 a, which can be formed in any way. It may be an electrically heated or an oil-fired boiler.

The heated water flows in the direction of the arrow 6 continue in the HD stage 4 to the spray lance 7 and is there at its outlet via a nozzle 8th as HD-beam 10 issued.

If the HD cleaner is to be operated in frost protection mode, it is envisaged that depending on one in a return line 13 arranged temperature monitor the temperature of the existing water is detected. The return line takes this at the washing area of the Spühlanze 7 discharged water and leads this a drain 15 to. The temperature detected there is a microprocessor 17 over the electrical line 25 fed. Its output regulates over the line 26 the frequency converter 18 ,

In antifreeze operation thus the frequency of the frequency converter of z. B. usually 50 Hz only to a value of z. B. 2 Hz down, causing the speed of the three-phase motor of z. B. 1000 U / min is reduced to 20 U / min.

In the frost protection mode, which can be maintained permanently, the HD pump 2 Therefore, only operated at a low speed continuously and therefore promotes only a small volume of water. It is envisaged that when the spray lance is closed 7 over one at the nozzle 8th or at the spray lance 7 arranged bypass opening 9 the low-volume water jet thus generated as antifreeze water 11 dripped down and from a stationary collection container 12 is caught. The collection container 12 is with the return line 13 connected, via which the outlet water in the arrow direction 14 to a process 15 runs and is omitted there.

The temperature monitor 16 is preferred in the return line 13 of the collection container 12 arranged because of this arrangement, a certain flow of antifreeze water in the return line 13 is given and in this area the risk of freezing the water is given primarily so that the temperature monitor 16 z. B. always monitors a minimum temperature of + 5 ° C and turns on the temperature below the frost protection mode.

The invention is not on the arrangement of the temperature monitor 16 in the return line 13 limited. The temperature monitor 16 can also be arranged elsewhere. In particular, it can detect the ambient temperature of the air and accordingly the microprocessor 17 drive.

In another embodiment, it can also be provided that two temperature monitors are provided, namely one that detects the temperature of the ambient air and the second, here called temperature monitor 16 , which is the temperature of the water returned in the frost protection mode in the return line 13 detected.

The signal of both temperature monitors or a differential signal formed therefrom is in the microprocessor 17 fed.

The 2 now shows the speed-controlled operation of the high-pressure cleaner in frost protection mode.

Starting from z. B. a temperature of 0 ° C in the ambient air up to a temperature of 40 ° C, the high-pressure cleaner should be operated as intended in its normal mode. This is in the curve branch 21 recognizable that from position 20 the normal rated speed of z. B. 1500 U / min for the three-phase motor 1 and thus for the high-pressure pump 2 is provided.

But as soon as the ambient temperature or the temperature in the return line 13 to a value of <0 ° C or in a range of z. B. + 5 ° C and -5 ° C drops, the speed of the high-pressure pump is controlled so that at position 22 a curved branch 23 is generated and at position 22 a number of revolutions of z. B. 2 U / min and at even lower temperatures such. B. -20 ° C a number of revolutions of 5 U / min and at -40 ° C a number of revolutions of 10 U / min are provided. The speed in the antifreeze operation is therefore changed linearly as a function of the linear decrease of the temperature. Instead of a linearly proportional increase of the speed with decreasing temperature, a non-linear control can be provided.

The 3 shows the operating mode "steam operation" of the high-pressure cleaner according to the invention.

The steam operation is according to 3 characterized in that the rotational speed of the three-phase motor 1 is reduced and the three-phase motor z. B. only in a frequency range of z. B. 10 to 40 Hz, whereby the speed of the high-pressure pump 2 and their volume flow is greatly reduced. But if the boiler 5 works with the same thermal performance as in normal operation, it comes in the high-pressure stage 4 to overheat the funded with lower flow from the HP pump water, which z. B. is thereby heated to 140 ° C.

According to the invention is in the HD stage 4 a temperature sensor 24 arranged, the microprocessor 17 over the electrical line 25 which in turn with its output 26 the frequency converter 18 controls.

The temperature sensor 24 and the speed control of the HP pump influenced by it always ensure that in the HD stage a temperature of 140 ° C, depending on the flow rate of the HP pump 2 is complied with.

That from the nozzle 8th discharged water (HD beam 10 ) is then a jet of steam, consisting of superheated steam.

In the third mode of operation of the HD cleaner according to the invention (surplus operation), the focus is on the fact that the HP pump should promote the largest possible volume flow of water with the temperature lowered.

For this purpose, the invention provides that the frequency converter is controlled to a frequency of more than 50 Hz, z. B. to a frequency in the range of 50 to 200 Hz, whereby the three-phase motor is controlled to a doubled or tripled speed and, accordingly, the high-pressure pump 2 a doubled or tripled volume flow of water into the boiler 5 into it.

In the high pressure stage 4 is a pressure sensor according to the invention 28 arranged, which determines whether the high-volume pumped water from a large-volume nozzle 8a is emitted from the spray lance, which automatically produces an HD beam 10a with a lower temperature of z. B. 50 ° results. The pressure sensor 28 also detects a switch between the large-volume nozzle 8a and a nozzle 8b , Both nozzles 8a . 8b are in the switching branch 25 arranged so that when switching the water from the "normal" HD nozzle 8b the spray lance is discharged, and thus a high temperature High pressure jet 10b with a temperature of z. B. 99 ° C is generated.

For such a surplus operation is characteristic that the frequency converter is regulated to higher frequencies than the useful frequency of 50 Hz, whereby the speed of the high-pressure pump is greatly increased and thus a larger volume flow of water is promoted.

LIST OF REFERENCE NUMBERS

1

Three-phase motor

2

HP pump

3

water supply

4

HP stage

5

boiler

6

arrow

7

Spray lance

8th

jet 8a . 8b

9

bypass opening

10

HP jet 10a . 10b

11

Antifreeze Water

12

receptacle

13

Return line

14

arrow

15

procedure

16

temperature Monitor

17

microprocessor

18

frequency converter

19

AC input

20

position

21

curve branch

22

position

23

curve branch

24

temperature sensor

25

management

26

management

27

switching branch

28

pressure sensor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2541383 A1 [0004]
• DE 3817432 A1 [0005]
• DE 1672216 B1 [0005]

Claims (9)

Method for operating a HD cleaner with different operating modes, the at least one HD pump ( 2 ), which is driven by a drive motor ( 1 ), whereby that of the HP pump ( 2 ) water drawn in on the intake side and through a heated boiler ( 5 ) and at least one spray lance ( 7 ), wherein the drive motor is regulated in its rotational speed, characterized in that in the operating mode "antifreeze operation" of the drive motor ( 1 ) is operated continuously at a reduced speed in comparison to normal operation, that for the operating state "steam operation", the speed of the drive motor ( 1 ) and thus the flow rate of the HP pump ( 2 ) is lowered so that the HP pump ( 18 ) with lower flow rate into the boiler ( 5 ), which is operated with the same thermal performance as in normal operation, so that there is an overheating of the lower volume flow from the HP pump pumped water, and that for the mode "excess operation" of the drive motor ( 1 ) is operated at a higher speed than in normal operation. A method according to claim 1, characterized in that the drive motor as a three-phase motor ( 1 ) formed by a frequency converter ( 18 ) is driven. A method according to claim 1 or 2, characterized in that in the "frost protection operation", the rotational speed of the three-phase motor ( 1 ) from Z. B. 2000 to 3000 U / min on a range of 50-2 U / min is lowered. Method according to one of claims 1 to 3, characterized in that in the operating state "steam operation" the water flowing through the boiler (which corresponds to a low flow rate) z. B. is heated to a temperature of 140 ° C. Method according to one of claims 1 to 4, characterized in that for the operating mode "surplus operation" of the three-phase motor ( 1 ) is driven at more than 50 Hz. Multi-mode HD cleaner for carrying out the method according to one of claims 1 to 5, which comprises at least one HP pump ( 2 ), which is powered by a drive motor ( 1 ), whereby that of the HP pump ( 2 ) water drawn in on the intake side and through a heated boiler ( 5 ) and at least one spray lance ( 7 ) is discharged, wherein the rotational speed of the drive motor is regulated. HD cleaner according to claim 6, characterized in that the drive motor as a three-phase motor ( 1 ) formed by a frequency converter ( 18 ) is driven. HD cleaner according to claim 6 or 7, characterized in that at the input of the frequency converter ( 18 ) applied mains frequency in a frequency range between 2 to 1000 Hz as the output frequency for the drive of the three-phase motor ( 1 ) is controllable. HD cleaner according to claim 8, characterized in that the regulation of the output frequency for driving the three-phase motor ( 1 ) as a function of sensors which can be used as temperature sensors ( 16 . 24 ) and / or as a pressure sensor ( 28 ) are formed.

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