CLEANING DEVICE AND METHOD FOR CLEANING OF HEAT EXCHANGERS
Provided is a cleaning apparatus for cleaning a finned type heat exchanger, having a distributing device (720) for distributing and applying cleaning medium (W, S, D) on the side surfaces of the fins, wherein said distributing device (720) is disposed transversely to the extension of the side surfaces of the fins, wherein an outlet side (730) of the distributing device (720) has a number of metering openings (73, 73′), adapted to the spacing of the fins, wherein at least one metering opening (73, 73′) is disposed between two successive fins. Also provided is a method for cleaning a finned type heat exchanger, including applying a cleaning medium (W, S, D) on the side surfaces of the fins by means of a cleaning apparatus according to the invention, wherein the method includes the steps of disposing a distributing device (720) of said cleaning apparatus transversely to the extension of the side surfaces of the fins, and initiating a cleaning sequence including applying said cleaning medium (W, S, D) on the side surfaces of the fins.
This application is a Continuation-in-Part of international patent application serial No. PCT/SE2013/051061, filed 11 Sep. 2013. This application also claims foreign priority to Swedish patent application serial No. 1251021-0, filed 11 Sep. 2012. The complete disclosures of these applications are incorporated herein by reference.
TECHNICAL FIELDThe present invention relates to a cleaning apparatus for cleaning a finned type heat exchanger, comprising a distributing device for distributing and applying cleaning medium on the side surfaces of the fins, and a method for cleaning a finned type heat exchanger, comprising applying a cleaning medium on the side surfaces of the fins by means of a distributing device according to the invention.
STATE OF THE ARTIt is commonly known that heat exchangers in different applications such as in air-conditioners, ventilation systems, refrigerators and freezers, are clogged by dirt and grease, which results in that the efficiency gradually declines and the compressor has to work harder. For example, in a grocery store with a large number of refrigerator and freezer display cases, this results in enormous refrigeration/freezing costs. When a heat exchanger is clogged by dirt etc., bacteria thrive, which is not preferable, especially not in connection with food products.
Cooling batteries are frequently mounted in inaccessible positions in the bottom or the back wall of a refrigerator/freezer display case. It is sometimes possible to get access to the actual cooling/heating battery, however only after removal of the surrounding parts, but the cleaning will still be awkward. Large resources are required for the cleaning of heat exchangers, which many times results in it being omitted. At the same, the fins in a heat exchanger are in most cases thin and easily damaged, which makes cleaning without damaging the fins difficult. The cleaning has usually consisted in vacuum cleaning removal of visible dust on the outside of the cooling battery, while attempts to clean the internal parts of the cooling battery have usually been made by means of pressurized air or high pressure rinsing with water. The last-mentioned methods are unsuitable. A high pressure cleaner will bend the fragile fins and destroy the heat exchanger. Furthermore, a large quantity of water is consumed and has to be recovered. There are some patented methods for the cleaning of heat exchangers.
A method of cleaning a heating, alternatively cooling battery in a heating or cooling apparatus is disclosed in document GB 2225828 A. After making the heating/cooling battery accessible, it is cleaned by means of a (wet) vacuum cleaner, detergent, and a combination of a water unit and an air compressor.
A cleaning apparatus and a cleaning method for the heat exchanger in an air conditioner are disclosed in document U.S. Pat. No. 5,509,972. A cover is fitted over a portion of the front side of the heat exchanger so as to serve as a splash shield when detergent followed by water are sprayed into the area covered by the cover.
BRIEF DESCRIPTION OF THE INVENTIONIt is an object of the present invention to eliminate, or at least minimize the above-mentioned problems, which is achieved in that a distributing device according to the invention is disposed transversely to the extension of the side surfaces of the fins, wherein an outlet side of the distributing device comprises a number of metering openings, adapted to the spacing of the fins, wherein at least one metering opening is disposed between two successive fins.
Thanks to the invention, a cleaning apparatus/method, which enables cleaning of a heat exchanger in situ without damaging the fins and with a considerably smaller quantity of water than the current cleaning methods, is provided.
According to a further aspect of the invention, the distributing device extends transversely to the extension of the side surfaces of the fins, and a number of metering openings, adapted to the spacing of the fins, are present on an outlet side of the distributing device, wherein at least one metering opening is disposed between two successive fins, which results in a better distribution of the cleaning medium across the cooling battery.
According to a further aspect, at least one metering opening is disposed between each of the fins, whereby cleaning medium is applied between all fins.
According to another aspect of the invention, the distributing device comprises a space having an inlet for the cleaning medium and a plurality of outlets comprising said metering openings, wherein said outlets are smaller in area than the inlet, whereby a uniform distribution of the cleaning medium can be achieved. Since the distributing device has an elongated shape and the metering openings are disposed such that the spray characteristic of the metering openings distributes the cleaning medium along the longitudinal extension of the heat exchanger, preferably along the entire length, and preferably also along the entire width of the heat exchanger, an efficient cleaning can be provided without requiring any manual action during the cleaning process.
According to a further aspect of the invention, said distributing device is at least upwardly, but preferably also laterally surrounded by a cover, wherein said cover preferably comprises a planar top portion, and preferably also downwardly directed edge portions, which are preferably adapted to surround the outer edge portions of the heat exchanger, which assists in directing/forcing the cleaning medium down between the fins and prevents splashes in other directions than downwards. In addition, the cover contributes to making it easy to place the cleaning apparatus on the heat exchanger, since the cover encloses the heat exchanger to a certain extent and thereby holds it in place.
According to another aspect of the invention, the distributing device comprises a distribution box, which is preferably flat for the purpose of minimizing the quantity of cleaning medium therein. Alternatively, the distributing device comprises at least one elongated pipe having a small diameter.
For the purpose of enabling cleaning of heat exchangers of greater depth, said elongated pipe is adapted to form pipe sections disposed substantially in parallel and fluidically connected to one another via a transverse connecting pipe comprising a connector for the connection of a feed device for said cleaning medium, alternatively constitutes a continuous pipe coil, wherein said connector is disposed at one end of the pipe coil.
According to another aspect of the invention, it is advantageous if the cleaning apparatus can be used for heat exchangers of different sizes, which is achieved in that the metering openings can be disposed within an angle on the outlet side of the pipe, and that the metering openings can be disposed in different ways, e.g. linearly or alternately about a central axis on the outlet side of the pipe.
By using a cleaning apparatus according to the invention, a method for cleaning of a finned type heat exchanger, comprising applying said cleaning medium on the side surfaces of the fins, can be provided. According to one aspect of the invention, the method comprises the step of disposing said distributing device transversely to the extension of the side surfaces of the fins, and initiating a cleaning sequence comprising uniformly distributing said cleaning medium on the side surfaces of the fins, whereby a uniform distribution of the cleaning medium is obtained.
Since the cleaning sequence comprises applying steam, preferably dry, superheated steam having a temperature (TS) of no more than 180° C. and a pressure of 2-20 bars, more preferably 8-12 bars, for a duration (t) adapted to the total area of the side surfaces of the fins such that a temperature (T) of at least 85° C. is reached on the side surfaces (Y) of the fins, an efficient cleaning and a bactericidal effect are obtained. Furthermore, the advantage is achieved that the quantity of water used will be small and that steam easily fills up the space between the fins and reaches all surfaces in a delicate manner, and thereby reduces the risk of damaging the fins.
Since the cleaning sequence also comprises the step of applying water (W), preferably hot water having a temperature (TW) of 70-120° C., for a duration adapted to the total area of the side surfaces of the fins such that a temperature of at least 65° C. is reached on the side surfaces of the fins and/or of applying cleaning chemicals, an efficient dissolution and removal of dirt from the side surfaces of the fins is obtained.
Since the cleaning medium is deionized, the risk of it conducting electricity is eliminated or at least minimized.
In the following, the invention will be described in more detail with reference to the attached figures of the drawings, in which:
In the description of the invention, the heat exchanger will be described as a cooling battery 2 in a refrigerator/freezer display case, but the skilled person will appreciate that the invention is applicable to all forms of heat exchangers, such as in air-conditioning and ventilation installations.
As mentioned by way of introduction, the cleaning of cooling batteries constitutes a problem, since they are often mounted in inaccessible positions in the bottom or back wall of a refrigerator/freezer display case, in the space formed between an inside wall and an outside wall, where, among other things, insulating material is placed. In those few cases when they are located in a more easily accessible position, cleaning still remains a rare event, since it is difficult and awkward to clean them. In the example below, the invention will be described with reference to a vertical refrigerator display case, but the skilled person will appreciate that the example also applies to a horizontal refrigerator display case, with the difference that the shelves 4 shown in
In the following, a cleaning apparatus and a method for simple and quick cleaning of a cooling battery 2 in situ, i.e. while the cooling battery 2 is mounted in a refrigerator/freezer display case of the kind shown in
Through the invention, a method for cleaning a cooling battery 2 is provided, wherein the fact that the cooling battery 2 is surrounded by the inside wall and outside wall of the refrigerator/freezer display case, which until now has been regarded as a complicating factor for the access to the cooling battery, is used instead together with a cleaning apparatus according to the invention to thereby achieve conditions favourable for the purpose, and thereby enable an efficient cleaning of the cooling battery 2. More specifically, the inside wall and outside wall, respectively, of the refrigerator/freezer display case surround the cooling battery along the sides towards which the edges of the fins are facing. Thus, the inside and outside wall of the refrigerator/freezer display case interact with the side surfaces of the fins so as to create confined spaces, resembling a duct/conduit/passage, between the fins. These confined spaces contribute to enabling the cleaning medium to be distributed more uniformly between the fins in the cooling battery and on the side surfaces thereof in an efficient way.
The applicant has developed a nozzle 7, said nozzle 7 being shown in a perspective view from above in
In a preferred embodiment, the nozzle 7 comprises a cover, suitably consisting of a substantially planar, rectangular top portion 70 having edge portions 74, 75, 76, 77, said edge portions extending substantially perpendicularly downward from said top portion 70. The edge portions comprise two long edge portions 74, 75 extending downwardly from the long sides of the top portion 70, and two short edge portions 76, 77 extending downwardly from the short sides of the top portion 70. Said long edge portions 74, 75 and short edge portions 76, 77 preferably have the same height, so that the lower edge of said long edge portions 74, 75 and short edge portions 76, 77 terminate in a common plane. This provides the advantage that, when the nozzle 7 is placed on top of the cooling battery 2 during cleaning, a closed space is provided between the cover of the nozzle, the outside and inside wall of the refrigerator/freezer display case enclosing the cooling battery 2, and the side surfaces of the outermost fins, which forms a duct/conduit/passage so that the cleaning media can be distributed more uniformly between the fins in the cooling battery 2. The cover is preferably made of composite plastic, which is durable, easy to keep clean, and enables a simple manufacture, e.g. by compression moulding, but it is appreciated that other materials can be used, such as bent sheet metal, and that other manufacturing methods can be used without taking away from the purpose of the invention. The cover can be provided with handles, which may be thermally insulated, for the purpose of facilitating the handling of the nozzle 7. The connector 71 is preferably disposed centrally on the top portion 70 and is adapted to be connected to a distributing device 720, disposed on the bottom side of the nozzle 7, via a sealed through-hole (not shown) in the top portion 70.
The metering holes 73 are adapted to apply a uniform flow and a uniform distribution of the fluids (detergents, steam, water) through the cooling battery and thereby ensure that all parts will be cleaned. The number of metering holes and their size can be varied as needed. For the purpose of providing a flow of cleaning medium which is sufficient to rinse away accumulated dirt on the side surfaces of the fins, but at the same time minimizing the quantity of fluid consumed, a version with fewer metering holes having a small diameter is preferred as compared to a version with fewer metering holes having a larger diameter. Suitably, the metering holes 73 have a diameter of 0.2-1.5 mm, preferably 0.5-1.0 mm, most preferably 0.6-0.8 mm, typically 0.7 mm, and have a spacing of 2-20 mm, preferably 2-15 mm, most preferably 2-10 mm.
In the shown embodiment, the metering holes 74 are circular with a diameter of 0.70 mm. The metering holes 73 are arranged along a central line and directed straight downward with a spacing of 10 mm. The length of the pipe 72 is about 625 mm, which corresponds to a common standard size for a cooling battery. Cooling batteries in larger sizes are often multiples of this standard size, i.e. 1250 mm, 1875 mm, and so on.
Another alternative can be that the pipe 72 is provided with one or several longitudinal slits so that the fluids are applied in a fan-shape (not shown). Transverse slits 73′ are also conceivable, see
It can also be advantageous that the distributing device 720 applies the fluid upwardly toward the top portion 70, by means of which the fluid flowing upward is surrounded by the top portion 70 and the edge portions 74, 75, 76, 77, and is thereby uniformly distributed therein, to then be forced downward towards the cooling battery 2 and in between the fins 20.
An alternative embodiment of a distributing device 720 according to the invention is seen in
As mentioned previously, the nozzle 7 is connected to a machine feeding the nozzle with steam, water, etc. The functions which the nozzle 7 should be provided with from the machine can preferably be entered on a display device on the handle of the machine so that the different functions are preprogrammed and followed in a predetermined continuous cleaning process. It is of course also possible to decide from case to case which cleaning steps that are to be included and in which order they are to be executed. Accordingly, it is appreciated that the same nozzle 7 is used throughout all steps in the cleaning process, which saves time and work steps. Preferably, in order to be able to clean most types of cooling batteries, an assortment of nozzles 7 of different sizes suitable for the most common modules is provided. Cooling batteries are normally made in certain standard sizes, and in larger sizes the dimensions are often multiples of the smallest module and therefore the same nozzle can be used for section-wise cleaning.
Another alternative embodiment of the distributing device 720 could be such that the distributing device 720, as in
In the following, it will be described how a preferred cleaning sequence is carried out, but it should be understood that also other combinations of cleaning steps can be used without therefore departing from the inventive concept and that other cleaning media than the ones described here, other flow rates, pressures and temperatures can be used.
Accordingly, during cleaning, the nozzle 7 is placed on top of the cooling battery 2. It is conceivable that that the nozzle 7 is placed such that the distributing device 720 bears against the fins 20, alternatively that the distributing device 720 is placed a small distance above the fins, but it is most preferred that the distributing device is disposed 0.5-1 cm above the fins 2. Preferably, the nozzle 7 has a size adapted to the exposed portion of the cooling battery 2 such that when the nozzle 7 is placed over the cooling battery 2, the edge portions 74, 75, 76, 77 of the nozzle close in around the uppermost portion of the cooling battery 2, so that the nozzle 7 is held in place without any additional means. An alternative embodiment of the nozzle 7 could be a telescopic solution, where the nozzle 7 can be extended to the desired length in the longitudinal direction, which enables the same nozzle 7 to be used for a number of cooling batteries of different lengths. Thereupon, the desired cleaning cycle is selected via a display device on the machine and the cleaning can start.
In a preferred cleaning cycle, the cleaning starts with the distributing device 720 applying a detergent D in the form of foam or spray between the fins, via the metering openings 73, 73′. The detergent preferably dissolves grease and has a pH value in the range of 4-9, since aluminium is sensitive to pH values outside this range. The skilled person will appreciate that if the cooling battery is made of another material than aluminium, the pH value can then be adapted to that material. The detergent is then left to act for a short time to dissolve dirt and grease. The duration will of course be determined by the degree of contamination and type of dirt and must be adapted thereto, but it is advantageous if the time consumption can be kept down. This step where detergent is applied and left to act on the cooling battery 2 has a maximum duration of 20 minutes, more preferably no more than 10 minutes, and most preferably the step has a maximum duration of 2 minutes. Examples of possible detergents are provided by the company Kylma (www.kylma.se) under the product ranges CoolSafe® refrigerator display case cleaner and EnviroCoil® evaporator cleaner.
As a second step, see
Steam is applied until it has filled the spaces between the fins 20, preferably from the top portion to a lower level N1 adjacent to a portion opposite to the portion that the distributing device 720 is applied to, see
The steam is followed by a rinsing step, see
Owing to this cleaning method, the fluid consumption is very small, a maximum consumption of water is 20 litres, more preferably a maximum consumption of 10 liters, and even more preferred is a maximum consumption of 1 liter of fluid, per cleaning sequence. A cleaning sequence then includes the three steps applying detergent, steam washing and rinsing. Then it is to be understood that one or several of the steps can be omitted, alternatively can be switched in order according to needs and desires. The quantity of water consumed in a cleaning sequence is to some extent also influenced by the size of the cooling battery 2 and the amount of dirt, and the above-mentioned consumption of fluid refers to a cooling battery of standard design as regards the ratio between length:depth:height, wherein the length amounts to a maximum of 1 m.
Additional advantages of the small quantities of steam and fluid in the cleaning method according to the invention is that the refrigerant in the pipe coil 21 has no time to be heated as much during a cleaning sequence. Since all pressurized systems today comprise safety valves that are triggered if, among other reasons, the refrigerant gets too hot, the triggering of the safety valves can be avoided by means of the cleaning method according to the invention. In the current methods of cleaning energy exchangers, air compressors, aerosols etc. are used, which means that bacteria and fungi are spread into the air, for example in a store. These methods require that the premises/store are/is closed, and sometimes also that the person performing the cleaning works in full protective suit to protect himself/herself. By means of the method according to the invention, energy exchangers can be cleaned without having to evacuate the premises where the energy exchanger is located, and the people working with the cleaning do not have to wear protective suits either, since the steam has a temperature which ensures that bacteria etc. are killed.
Excess water/condensed water flows downward through the cooling battery 2 and then follows the existing arrangement for the normal condensed water in the refrigerator display case 1, which is usually arranged to pass to some kind of sewer/floor drain. The small amount of water used in the cleaning facilitates cleaning of cooling batteries 2 while the store is open, whereas otherwise there is a risk that water spills out on the floor. An alternative that is particularly advantageous when cleaning large cooling batteries 2, where the steam has to be forced a longer distance to reach all the way to the lower part of the cooling battery 2, can be to connect a wet vacuum cleaner 9 to the side of the cooling battery that is opposite to the side to which the distributing device 720 is applied. Thereby, the wet vacuum cleaner 9, on the one hand, produces suction from the opposite side, which makes it easier to get the steam to pass through all the way along the fins 20, and, on the other hand, the wet vacuum cleaner 9 directly collects the fluid used during the cleaning.
Yet another advantage of the cleaning method according to the invention is that a cleaning sequence according to the preferred embodiment, with the three cleaning steps detergent, steam and rinse, occupies a short time, of a maximum duration of 20 minutes, more preferably the cleaning sequence has a maximum duration of 10 minutes, and most preferably a maximum duration of 5 minutes. Thanks to the short duration of a cleaning cycle comprising all three steps, many refrigerator/freezer display cases can be cleaned in a short time. It should also be mentioned that the cleaning of the cooling batteries 2 takes place in situ and also can be done in day time when the stores are open, since there is no need for moving the refrigerator/freezer display cases. Also the small quantity of water used and the short cleaning time contribute to the fact that it is possible to perform the cleaning during the opening hours of a store. To further improve the situation for the store when the cleaning takes place during opening hours, it is possible to hang a curtain or the like in front of the open part of the refrigerator/freezer display case to prevent steam/condensation from spreading outside the actual refrigerator/freezer display case. It is also possible to place ice in a wet vacuum cleaner 9, if such a machine is used, wherein the ice causes the steam to condense inside the wet vacuum cleaner and it does pass directly through the machine and out into the room.
The problem with clogged, dirty cooling batteries results in a reduction of the effectiveness of refrigerator/freezer display cases, since the efficiency gradually declines at the same time as the compressor has to work more. This means than stores with many refrigerator/freezer display cases have enormous electricity costs, and they can, owing to the invention, reduce their energy consumption by 10-40% of the share used for refrigeration/freezing. From a general point of view, it can be said that the share of refrigeration/freezing constitutes about 50% of the total energy consumption in a grocery store. Considerable savings can be made for each meter of cooling battery and, accordingly, there are great cost savings to be made by regularly cleaning the cooling batteries in a refrigerator/freezer.
According to the inventive concept, it is also possible that a distributing device 720 is fixedly mounted above a cooling battery for periodic cleaning, for example by being fastened by means of clips. In that case, it is advantageous to use a distributing device 720 without any cover, to not unnecessarily restrict the passage of the cooling air through the cooling battery and further through the conduits for distributing the cooled air of the refrigerator/freezer display case. In this case, the distributing device 720 is fixedly mounted above the cooling battery 2, in accordance with the principle of mounting it adjacent to the fins that has been described above, and connected to a machine, for example Steam Pressure as described previously. The cleaning of the cooling battery 2 can then be performed periodically to prevent the cooling battery from being clogged by dirt and grease, which causes the efficiency to gradually decline.
An alternative embodiment of a cleaning device according to the invention is depicted in
In
Another variant of arranging a distributing device 720 in the cooling battery 2 during manufacture is to leave out one or several horizontal sections of the pipe coil 21 for the refrigerant, and to use these holes in the fins 20 for the distributing device 720. It is also appreciated that it is possible to provide the fins with extra holes in which a distributing device 720 according to the invention can be disposed in a retrofitting operation. Alternatively one or several pipe coils for refrigerant in the cooling battery can be removed to thus provide space for mounting a distributing device therein. According to the inventive concept, it is also possible that a distributing device 720 is fixedly mounted above a cooling battery 2 during manufacture.
In the case when a distributing device 720 is arranged in a cooling battery 2 during manufacture and/or by retrofitting, it is advantageous to use a distributing device 720 without any cover, to not unnecessarily restrict the passage of the cooling air through the cooling battery and further through the conduits for distributing the cooled air of the refrigerator/freezer display case. If the advantages that can be offered by a cover are still desired, i.e. that it contributes to forcing/directing the steam downward through the fins, there is the possibility of placing a loose cap, screen, or something else confining the space, such as a piece of sheet metal, on top of the cooling battery 2, so that the major part of the steam is forced to take the intended path through the fins 20. It is of course also possible to fit some kind of cap/cover, during the manufacture, disposed on the cooling battery 2, or adjacent to the cooling battery 2 by means of hinges, so that it can easily be folded down during the cleaning session. It is of course appreciated that it is also possible that the cleaning process is carried out without any cap/cover, but that the pressure of the steam has to be raised to enable it to be forced down through the fins. It is also appreciated that it is possible to arrange one or several distributing devices 720 in a cooling battery. For example, in a very high battery, there can be two or more levels of distributing devices 720. In that case one can optionally choose to operate one or several of the distributing devices 720. Since the flow through the battery passes from the bottom upwards, more dirt is accumulated at the lower end, and with this embodiment one can then choose to clean the lower end more frequently than other parts/the whole battery.
The invention is not limited to what has been described above, but can be varied within the scope of the following claims. For instance, it is appreciated that detergents, steam, etc. can expelled from the nozzle 7 through passages, said passages being an integrated part of the top portion 70 of the actual nozzle. A conceivable embodiment comprises a flat distribution box, for the purpose of minimizing the quantity of cleaning medium therein, wherein a lower plate comprises said distributing openings. In spite of the fact that the described example deals with a cooling battery, the skilled person will also understand that the cleaning method is suitable for all forms of heat exchangers. It is also appreciated that the cleaning of a heat exchanger can be done from any side of the heat exchanger, entirely depending on how the heat exchanger is placed in its application, and where it is most easily accessible to the nozzle.
Claims
1. A cleaning apparatus for cleaning a finned type heat exchanger, comprising:
- a distributing device for distributing and applying cleaning medium on the side surfaces of the fins, wherein said distributing device is disposed transversely to the extension of the side surfaces of the fins, wherein an outlet side of the distributing device comprises a number of metering openings, adapted to the spacing of the fins, wherein at least one metering opening is disposed between two successive fins.
2. The cleaning apparatus according to claim 1, wherein at least one metering opening is disposed between each of the fins.
3. The cleaning apparatus according to claim 1, wherein said distributing device comprises a space having an inlet for the cleaning medium and a plurality of outlets for uniformly distributing the cleaning medium, wherein said outlets are smaller in area than the inlet.
4. The cleaning apparatus according to claim 3, wherein said outlets comprise said metering openings.
5. The cleaning apparatus according to claim 3, wherein said distributing device has an elongated shape, that the metering openings are disposed such that the spray characteristic of the metering openings distributes the cleaning medium along the longitudinal extension of the heat exchanger.
6. The cleaning apparatus according to claim 1, wherein said metering openings comprise metering holes, which have a diameter of 0.2-1.5 mm, and have a spacing of 2-20 mm.
7. The cleaning apparatus according to claim 1, wherein said metering openings comprise metering slits, which have a width of 0.1-1.5 mm and have a spacing of 2-20 mm.
8. The cleaning apparatus according to claim 1, wherein said distributing device is at least upwardly surrounded by a cover.
9. The cleaning apparatus according to claim 1, wherein said distributing device comprises a distribution box for the purpose of minimizing the quantity of cleaning medium therein.
10. The cleaning apparatus according to claim 1, wherein said distributing device comprises at least one elongated pipe, and that said pipe has a diameter of no more than 15 mm for the purpose of minimizing the quantity of cleaning medium therein.
11. The cleaning apparatus according to claim 10, wherein said elongated pipe is adapted to form pipe sections disposed substantially in parallel for distributing said cleaning medium via said metering openings.
12. The cleaning apparatus according to claim 11, wherein said distributing device comprises a plurality of elongated pipes being fluidically connected to one another via a transverse connecting pipe.
13. The cleaning apparatus according to claim 12, wherein said metering openings are disposed along the pipe within an angle of (v)±60° from an imaginary line (L) through the central axis of the pipe which is parallel to, or substantially parallel to the extension of the side surfaces.
14. The cleaning apparatus according to claim 13, wherein said metering holes are linearly disposed substantially in parallel with the longitudinal direction of the pipe.
15. The cleaning apparatus according to claim 14, wherein said metering holes are alternately disposed on respective sides of said line (L).
16. A method for cleaning a finned type heat exchanger, comprising applying a cleaning medium on the side surfaces of the fins, wherein the cleaning medium is applied by means of a cleaning apparatus, and wherein said cleaning apparatus has a configuration according to claim 1, wherein the method comprises the following steps:
- a) disposing a distributing device of said cleaning apparatus transversely to the extension of the side surfaces of the fins, and
- b) initiating a cleaning sequence comprising applying said cleaning medium on the side surfaces of the fins.
17. The cleaning method according to claim 16, wherein the cleaning sequence comprises applying steam having a temperature (TS) of no more than 180° C. and a pressure of 2-20 bars for a duration (t) adapted to the total area of the side surfaces of the fins such that a temperature (T) of at least 85° C. is reached on the side surfaces (Y) of the fins.
18. The cleaning method according to claim 16, wherein the cleaning sequence comprises any one or both of the steps:
- c) applying water (W) for a duration adapted to the total area of the side surfaces of the fins such that a temperature of at least 65° C. is reached on the side surfaces of the fins and/or
- d) applying cleaning chemicals (D).
19. The cleaning method according to claim 18, wherein the water has a pressure in the range of 2-20 bars.
20. The cleaning method according to claim 18, wherein the cleaning chemicals have a pH value in the range of 4-9.
21. The cleaning method according to claim 17, wherein the steam (S) and water (W) are deionized.
22. The cleaning method according to claim 18, wherein the quantity of water (W) amounts to no more than 20 per cleaning sequence.
23. The cleaning method according to claim 16, further comprising collecting cleaning medium (W, S, D) and any removed dirt below the fins of the heat exchanger.
Type: Application
Filed: Mar 10, 2015
Publication Date: Jul 30, 2015
Inventors: Ulf Lindström (Klassbol), Ulf Andersson (Arvika)
Application Number: 14/642,802