WO2020245174A1

WO2020245174A1 - Device for generating steam

Info

Publication number: WO2020245174A1
Application number: PCT/EP2020/065318
Authority: WO
Inventors: Helmut Barbisch
Original assignee: Swisslogo Ag
Priority date: 2019-06-03
Filing date: 2020-06-03
Publication date: 2020-12-10
Also published as: EP3977010B1; EP3977010A1

Abstract

The invention relates to a device for generating steam, in particular a supply device for an external cleaning machine that operates with steam, which cleaning machine can be connected by means of at least one flexible hose line, the device for generating steam comprising at least a pump and a steam generator, to which water coming from the pump can be fed at an operating pressure, which preferably is adjustable, during normal operation and which outputs pressurized steam, in particular dry steam. Intermittently, water can be fed to the steam generator (11) from the pump (2) at a cleaning pressure above the operating pressure in order to remove deposits, in particular limestone, from the steam generator (11).

Description

Device for generating steam

The invention relates to a device for generating steam according to the preamble of claim 1. Furthermore, the invention relates to a cleaning device in which such a device for generating steam is used and a cleaning machine is used.

The generation of steam (water vapor) is known for the most varied of purposes. In particular, it is known to use superheated dry steam for cleaning purposes, in which case the steam is under pressure.

In the steam generator, which is preferably designed as a once-through boiler, there are deposits, in particular limestone, which reduce the effective cross-section of the lines or pipes in the steam generator and, in the worst case, clog them completely.

In order to solve this problem, the invention proposes a device according to the features of claim 1.

According to the invention, at least one pump is thus provided which can deliver water at a pressure which is above the normal operating pressure. This so-called cleaning pressure can temporarily be supplied to the steam generator in order to remove deposits, in particular limestone, from the steam generator. This is preferably possible in the form of pressure surges so that the covering comes off due to short-term material expansion. However, longer, continuous (that is, not jerky) exposure of the steam generator to water, the pressure of which is at an increased cleaning pressure, is also possible. The cleaning process can be activated automatically, for example by measuring the differential pressure across the steam generator, with the cleaning process taking place automatically from a certain pressure drop, that is, the application of a cleaning pressure above the operating pressure. But it is also possible to activate the cleaning process manually. Others too Parameters, for example a direct measurement of the thickness of the deposits, can be used as an output variable for activating the cleaning process (removal of the deposits). In principle it would be conceivable to use two different pumps for providing the operating pressure on the one hand and for providing the cleaning pressure on the other hand. But you can also get by with a pump (a high pressure pump) by regulating the pressure leading from the pump to the steam generation via a pressure regulator or a similar device and / or running the pump in normal operation on the one hand and in cleaning operation on the other hand with different output pressure.

Particularly preferred is an embodiment in which two line strands lead from the pump to the steam generator, which can be optionally activated via a switchover valve. In a first line branch, which is responsible for normal operation, an operating pressure can be set on an adjustable pressure regulator. Further components such as a throttle, a flow switch, an overpressure safety valve, an overpressure safety switch and a check valve can also be arranged in this first line branch.

In the second line that leads to the pump and which is responsible for the cleaning process, a decalcifying device for supplying a decalcifying agent (for example formic acid) can be provided. The decalcifying agent can also be supplied in other ways (i.e. not in a second line of pipes).

In general, the decalcifying agent will be fed to the steam generator and, after a certain exposure time, it will be subjected to increased cleaning pressure in order to safely remove the deposits from the combination of decalcifying agent - pressurization with cleaning pressure. For cleaning purposes in particular, the operating pressure generated by the pump is advantageously between 10 and 20 bar. The cleaning pressure, however, is more favorable than 150 bar. Regardless of the absolute level of the cleaning pressure and the operating pressure, the cleaning pressure should be at least five times, preferably at least eight times, higher than the operating pressure in normal operation in order to achieve good removal of deposits in the steam generator and thus its cleaning. Especially with the version described above with two different line strands, it is possible to use the increased pressure in the second line strand not only for cleaning, but optionally also for a cold water outlet with high pressure, for example to rinse out corners that are difficult to access with a cleaning device. The increased pressure is thus optionally used on the one hand to clean the steam generator and on the other hand to provide a cold water outlet under pressure. There is thus a favorable double use.

The device according to the invention for generating steam can be designed as an essentially autonomous, mobile unit which is designed to be self-propelled, for example, or which can be charged on a loading area of a vehicle. Essentially autonomous means that the essential components are combined to form a mobile unit and essentially only the water supply needs to be provided from the outside. In special cases this can even be integrated in a tank in the facility.

The autonomous, mobile unit can have a battery in order to be independent of a power connection, although a power connection via a power cable is also quite conceivable and possible. If such a battery is provided, it is advantageous if it can be charged and is charged, for example, via a mains connection or an internal combustion engine including a generator. The

Combustion engine can also be used to drive the pump (high pressure pump). The tank for the fuel of the internal combustion engine (preferably diesel) is then preferably integrated in the autonomous, mobile unit. The device according to the invention for generating steam is particularly suitable for use in cleaning devices in which a preferably hand-operated cleaning device is connected to the device for generating steam via at least one flexible hose. The cleaning device itself has at least one steam outlet in order, for example, to remove residues from floor surfaces. In addition to the steam outlet, at least one rotatable brush is advantageously provided in order to also mechanically loosen the dirt on the floor. Cleaning devices of different construction, for example arranged directly on a vehicle, are also entirely conceivable and possible.

Further advantages and details of the invention are explained in more detail with reference to the following description of the figures: FIG. 1 shows a schematic circuit diagram of an embodiment of a device according to the invention in normal operation,

Fig. 2 shows the same embodiment in the cleaning mode (removal of the deposits in the steam generator),

Fig. 3 shows the same embodiment in the setting "cold water - floch pressure",

Fig. 4 shows a schematic view of an embodiment of a device according to the invention in a schematic side view.

Fig. 5 shows a schematic circuit diagram of a further embodiment of the device according to the invention.

In the device shown in FIG. 1 in normal operation (180 degrees dry steam setting), water is sucked in by a suction pump (here a side channel centrifugal pump) and fed to the pump 2 designed as a high pressure pump. From there the water reaches the three-way valve 4 at high pressure; the pressure can be read off via a pressure manometer 3 or can also be fed to an electronic control device (not shown here). For the Dry steam generation (normal operation) the three-way valve 4 is brought to a position 4, 2, with which the pressurized water reaches the pressure regulator 5 and from there via a nozzle (throttle) 6, via a flow switch 7 and via an overpressure safety valve 13 and a Overpressure safety switch and finally via a non-return valve 10 to the actual steam generator 11, which is designed as a tubular boiler, in which the pipeline extends, preferably helically, around the combustion chamber and the combustion chamber itself can be heated via an oil burner 11 a in order to use the supplied water the pipes to generate steam. The dry steam generated then reaches the outside via a temperature regulator 12 and an overpressure safety valve 13 and can, for example, be fed to a cleaning device via a special steam hose, as is shown schematically in FIG. 4, for example. The cleaning device shown there is shown only in a simplified manner, in particular for

Removal of chewing gum, this cleaning device can of course also comprise further components, especially rotatably driven brushes.

If too little water flows through the flow switch / flow monitor 7, this switches off the oil burner 11a in the steam generator and the

Dry steam generation is interrupted for safety reasons. The components 8 and 9 also serve safety aspects that cause the oil burner 11 a to be switched off in the event of boiler calcification or some other malfunction.

The outlet-side safety valve 13 opens when the steam flow is interrupted, for example by force.

For decalcification according to the invention, the three-way valve is now - as shown in FIG. 2 - brought into position 4.1, whereby the second line section from the pump 2 to the steam generator 11 is activated. This second wiring harness comprises components 14 to 19, while the first wiring harness active in FIG. 1 has components 5 to 10.

In the position shown in FIG. 2, the decalcifier 11 is cleaned by removing the deposits. The water passes from the high pressure pump to a pressure regulator 14, which in the exemplary embodiment is set to 170 bar, for example. The pressurized cold water then passes via an overpressure safety valve 15 to a further three-way valve, which is in position 17, 2 here. In the device 18 for supplying a decalcifying agent, a decalcifying agent can be metered into the line, for example via a Venturi nozzle. This descaling agent is, for example, an acid or vinegar, in particular formic acid. The mixture of water and decalcifying agent then reaches the inlet of the steam generator via the non-return valve 9 and finally in its pipes inside. The calcification in the boiler (steam generator) 11 is flushed out by the water pressure of 150 bar and more in particular. It is also possible to let the water-decalcifying agent mixture take effect, for example for a period of 20 minutes and then switch on the high-pressure pump 2 again to rinse the water-decalcifying agent mixture from the steam generator together with the removed deposits. Finally, this rinsed mixture can be fed to a suitable drain.

The described decalcification process can be activated manually, but it is also possible to measure operating parameters, such as the pressure drop across the steam generator, and to use this variable as a trigger for an automatic decalcification procedure.

It is also possible to achieve preferred pressure surges via an electromagnetically controlled valve in order to efficiently remove the limescale. The pressure relief valve 15 itself can also contribute to a varying pressure in that it opens in the event of a high level of calcification of the steam generator, so that the pressure drops and then rises abruptly again because of the calcification. There is an "up and down" of the pressure until the last remnants of the deposits in the steam generator have blown off. At the same time or afterwards, the boiler can be rinsed using the water-decalcifying agent mixture. In the position shown in FIG. 3, the high pressure present in the second conduit is used to serve a cold water outlet. For this purpose, the three-way valve 17 is brought into position 17, 1. So you can use the available high pressure not only for cleaning purposes of the steam generator (boiler), but also for an additional purpose, namely the Provision of cold water under high pressure, for example for cleaning purposes, via a hose and a suitable outlet nozzle.

In the exemplary embodiment shown in FIG. 4, one sees a carrier 20 in the form of a frame which, in the sense of a mobile autonomous unit, carries the essential components of an exemplary embodiment of the device according to the invention for generating steam. These include in particular the steam generator 11 itself, which has a tubular line 11b around a combustion chamber, through which water under operating pressure is passed in normal operation and converted to steam. This steam then emerges via the outlet line 21 and can, for example, be a hand-held one, generally designated 23

Cleaning device are supplied. This has, for example, a handle 24 and wheels 25 and outlet nozzles 26 for the steam. In practice, this cleaning device 23 can also be designed in more detail, for example with rotatably mounted brushes in order to clean a floor surface.

Now back to the autonomous steam generator. In addition to the steam generator 11 with an oil burner 11 a, this has a fan 11 c. The combustion gases escape from the steam generator 11 via a chimney 11 d.

A high-pressure pump 2 is driven by a diesel engine 27 with a diesel tank 28, in particular via a belt or chain drive, and supplies water under pressure via the line 29 to a valve and control unit, shown generally at 30. In the unit 30, the components of which can also be located at other locations, as shown in FIG. 3, essentially the components 3 to 10 and 14 to 19 of FIGS. 1 to 3 are located. The cold water can be via a tank in the unit itself or via a cold water connection 31 from the outside.

The diesel engine 27 can also drive a generator 32, which supplies power to a rechargeable battery (not shown here) in order, for example, to supply electrical components of a control or also lighting with power. Fig. 5 shows a further embodiment. The same reference symbols denote the same or similar components as in FIGS. 1 to 4. The essential difference between FIG. 5 and FIGS. 1 to 3 is that in FIG. 5 two separate pumps 2, 2 'are provided. The pump 2 'is set to a lower pressure and essentially serves to supply water for generating steam. The pump 2 is set to a higher pressure, for example 130 to 150 bar. It serves on the one hand to provide water under floch pressure for cleaning the tubular boiler / steam generator 11. In another position of the 3-way valve 16, the water from the pump 2 is fed, for example, to a lance for cold water high-pressure cleaning. The two pumps 2, 2 'allow two people to work at the same time, one with superheated steam and the other with high-pressure cold water.

The pumps 2, 2 ‘can be driven (for example by an electric motor or magnetically) switchable clutches with a drive unit (for example a diesel engine). Both pumps 2 and 2 ‘can be connected to a tank or a drain via a return 33.

Such a coupling can also be used to drive a separate dirty water suction turbine 34 which can be connected to the cleaning device 23 (FIG. 4) via a suction line. This dirty water suction turbine 34 can be used to convey dirty water into a tank (not shown).

The device according to the invention is particularly suitable for generating steam for a cleaning device for cleaning floors, but other uses are quite conceivable and possible.

Claims

1. A device for generating steam, in particular a supply device for an external cleaning machine that can be connected via at least one flexible hose line and that works with steam, the device for generating steam having at least one pump and a steam generator to which the water coming from the pump under normal operation a - preferably adjustable - operating pressure can be supplied and the pressurized steam, in particular dry steam, emits, characterized in that the steam generator (11) from the pump (2) can be supplied temporarily with water at a cleaning pressure above the operating pressure to remove deposits, in particular Limestone to be removed from the steam generator (11).

2. Device according to claim 1, characterized in that a pressure regulator (5) is arranged in at least one line leading from the pump (2) to the steam generator (11).

3. Device according to claim 1 or 2, characterized in that two lines (5 to 10, 14 to 19) lead from the pump (2) to the steam generator (11), which can be optionally activated via a switching valve (4) (Fig. 1 to 3) or at least two separate, preferably identically constructed, pumps (2, 2 ') are provided, one of which is assigned to one of the two line strands (FIG. 5).

4. Device according to claim 3, characterized in that the first line strand (5 to 10) is designed for normal operation and one on the

Has operating pressure adjustable or set pressure regulator (5).

5. Device according to claim 3 or 4, characterized in that the second line section (14 to 19) is designed for the cleaning operation and has a pressure regulator (14) which is adjustable or set to the cleaning pressure.

6. Device according to one of claims 3 to 5, characterized in that at least one of the following components is arranged in the first wiring harness: - a throttle (6)

- a flow switch (7)

- an overpressure safety valve (8) and / or

- an overpressure safety switch (9) and

- a check valve (10).

7. Device according to one of claims 3 to 6, characterized in that at least one pressure relief valve (15) is arranged in the second conduit.

8. Device according to one of claims 1 to 7, characterized in that the steam generator (11) can be supplied with a cleaning pressure which varies over time - preferably intermittently.

9. Device according to claim 8, characterized in that the pressure surges are caused by an electronic control device that can be controlled by an electrically controllable valve.

10. Device according to claim 8, characterized in that the pressure surges are generated via a pressure relief valve (15) which automatically opens when a maximum cleaning pressure is exceeded with a decrease in pressure in the line and then closes with a pressure build-up in the line.

11. Device according to one of the preceding claims, characterized in that a decalcifying device (18) is provided for supplying a decalcifying agent into a line leading from the pump (2) to the steam generator (11).

12. Device according to claim 11 and one of claims 3 to 7, characterized in that the decalcifying device (18) is arranged in the second line strand.

13. Device according to claim 11 or 12, characterized in that the decalcifying agent contains at least one acid, preferably formic acid or vinegar.

14. Device according to one of claims 11 to 13, characterized in that a Venturi nozzle is provided to supply the decalcifying agent to the line.

15. Device according to one of claims 3 to 14, characterized in that a valve (17) is arranged in the second conduit, via which pressurized water can optionally be fed to the steam generator (11) or a cold water outlet.

16. Device according to one of the preceding claims, characterized in that the operating pressure generated by the pump (2), preferably high-pressure pump, and reduced via a pressure regulator (5) is between 10 and 20 bar.

17. Device according to one of the preceding claims, characterized in that the cleaning pressure generated by the pump (2), preferably high-pressure pump, is above 150 bar.

18. Device according to one of the preceding claims, characterized in that the cleaning pressure is at least five times - preferably at least eight times - higher than the operating pressure in normal operation.

19. Device according to one of the preceding claims, characterized in that the temperature of the steam from the steam generator is above 150 degrees Celsius - preferably around 180 degrees Celsius.

20. Device according to one of the preceding claims, characterized in that the steam generator (11), which is preferably designed as a flow boiler, is a tubular boiler in which a pipeline - preferably helical - in the Wall of a by means of a burner (11 a) heatable combustion chamber is arranged.

21. Device according to one of the preceding claims, characterized in that the pump (2) is driven by an electric motor or an internal combustion engine (27), preferably a diesel engine.

22. Device according to one of the preceding claims, characterized in that the device is designed as an essentially autonomous, mobile unit which, for example, is designed to be self-driving or can be charged on a loading area of a vehicle (FIG. 4).

23. Device according to one of the preceding claims, characterized in that the essential components, in particular the pump (2), its drive motor (27), the steam generator (11), the connecting lines and valves arranged therein, on or in a common support frame (20) are attached.

24. Device according to one of the preceding claims, characterized in that a motor (27) driving the pump (2) also drives a generator (32) whose electric current can be stored in a rechargeable battery.

25. Cleaning device with a device according to one of claims 1 to 24 and at least one, preferably hand-held, cleaning device (23) connected thereto via at least one flexible hose (21).

26. Cleaning device according to claim 25, characterized in that the cleaning device (23) has at least one steam outlet and preferably at least one rotatable brush.

27. Use of a cleaning device according to claim 25 or 26 for removing soiling, in particular chewing gum residues, on floor surfaces.