HEIMGÅRD, Bjørn Egil (N-6433 Hustad, NO)
| A system for cleaning at least one closed space, comprising at least one liquid ring compressor for supply/discharge of large amounts of fluid to/from the space, characterised in that the system further comprises a cleaning fluid supply system comprising at least one atomizing device mounted in the space, which is connected to the liquid ring compressor for supply of gas, with a liquid crusher arranged downstream of the liquid ring compressor and upstream of the atomizing device, with a gas outlet from the liquid crusher connected to the atomizing device. A system according to claim 1 , characterised in that it is arranged on a vessel, for example a well boat, a ring net boat or a food products carrier, and the closed space is a cargo hold for transport of foodstuffs. A system according to claim 1 or 2, characterised in that the closed space is production premises and/or a pipe. A system according to one of the preceding claims, characterised in that a supply line is connected to the atomizing device for supply of a cleaning agent to the gas which is passed through the atomizing device. A system according to claim 4, characterised in that the atomizing device comprises an ejector, where the gas from the liquid ring compressor is the driving fluid and cleaning agent is drawn from the supply line into the gas stream. A system according to claim 4 or 5, characterised in that the cleaning agent supply line is connected to different cleaning agent sources and/or a water source. A system according to one of the preceding claims, characterised in that the water crusher comprises an inlet leading towards a conical element arranged internally in the water crusher. A system according to one of the preceding claims, characterised in that a control unit is mounted on the liquid ring compressor, thereby enabling it to be switched from a position where it supplies fluid to/from the cargo hold to a position where it supplies fluid to the cleaning fluid supply system and back again. A method for cleaning a cargo hold on a vessel, where a liquid ring compressor is arranged to supply fluid to a cleaning fluid supply system, where this fluid is conveyed to a liquid crusher, the gas from the liquid crusher is atomized in the cargo hold, and where during the atomizing process the necessary cleaning agent and/or other liquid is added. 10. The use of a water ring compressor on a vessel in order to provide driving fluid in a cleaning process for cleaning cargo holds on the vessel. |
The present invention relates to a system for cleaning at least one closed space, preferably a cargo hold on a ship for transport of foodstuffs, such as for example fish.
When transporting articles of food there are strict requirements with regard to hygiene and regular washing of the cargo holds in the vessel is essential. Similar demands exist for production premises and/or on shore slaughterhouses.
For washing a closed space of this kind, such as for example a cargo hold on a boat, a possible solution is for personnel to enter the cargo hold and carry out a more manual washing of the cargo hold. This presents challenges with respect to health, environment and safety aspects, not only because the personnel are exposed to the risks involved in the actual activity, but also because of the use of chemicals in this washing process. From EP1935515 A2 a cleaning system is known which uses spray nozzles and compressed air as a driving medium. WO2005051558 A2 describes a system for tank cleaning with spray nozzles for supplying cleaning agent, GB1428841 describes a mist generator using a venturi and US5653776 describes a scrubber with a liquid separator.
It is therefore a wish that this washing process should be able to be carried out without subjecting personnel to these risks and also in such a manner that a washing process is achieved which produces less environmental pollution.
This has been achieved with a system, method and use according to the invention.
A system has been provided for cleaning of at least one closed space, where the system comprises at least one liquid ring compressor for supply and/or discharge of large amounts of fluid to and from the space. The closed space may be a cargo hold on a vessel, production premises on shore, for example a fish slaughterhouse, and associated pipes connected therewith. This liquid ring compressor is therefore employed for loading and unloading foodstuffs/cargo into and from the space. This liquid ring compressor is advantageously a water ring compressor. Alternatively, another type of liquid ring compressor may be employed with another liquid than water, for example chemicals which are not harmful to the foodstuffs, for example the cargo transported by the vessel. This cargo may be live fish or frozen fish or another foodstuff. The system may be used in connection with a cargo hold on a vessel where the vessel may be a boat, but it is conceivable that the system described below could also function on other types of land-going vehicles.
Alternatively, the system may be employed for production premises and associated pipes, for example a salmon slaughterhouse. In this context a closed space should be understood to be a space which is delimited, such as for example a cargo hold, production premises and/or also pipes.
In this application cleaning should be understood to comprise both washing, disinfection and chemical treatment.
According to the invention the vessel further comprises a cleaning fluid supply system comprising at least one atomizing device arranged in the space/cargo hold, which is connected to the liquid ring compressor for supply of air to the atomizing device. In the connection between the liquid ring compressor and the atomizing device, a liquid crusher is provided downstream of the liquid ring compressor. A gas outlet from this liquid crusher is connected to the atomizing device.
With such a device a cleaning fluid supply system is obtained with great air supply capacity. Furthermore, this air contains a good deal of liquid, normally water, which is carried along with the air from the liquid ring compressor and is further crushed in the liquid crusher, with the result that it follows the air out of the gas outlet from the liquid crusher. An advantageous air/liquid mixture is thereby obtained in the atomizing device in the space/cargo hold.
According to an aspect of the invention the atomizing device may be connected to a supply line for supply of a cleaning agent to the gas which is passed through the atomizing device. One or more cleaning agents can thereby be mixed in, for example a chemical cleaning agent into the gas which is atomized in the atomizing device. According to an embodiment the cleaning agent supply line may be connected to different cleaning agent sources, whereby the cleaning agent concerned may be mixed and/or selected. The cleaning agents may be various soaps, disinfectants or other chemical cleaners. In this system valves and a regulation system will naturally be included for adjusting the valves for selecting the different cleaning agents.
According to an aspect the atomizing device may comprise an ejector, where the gas from the liquid crusher downstream of the liquid ring compressor is the driving fluid and cleaning agent is drawn from the supply line into the gas stream. By means of such a solution the system can be substantially driven by the pressure created by the liquid ring compressor. In another embodiment a booster system may also be provided in the cleaning agent supply line or in the sources for the cleaning agents.
According to yet another aspect the cleaning agent supply line may also be connected to a water source. By further mixing water into the supply to the space/the cargo holds, the cargo holds and associated pipe systems and other equipment can also be flushed in a final part of a washing process. In order to further increase the effect of the washing operation, in an embodiment the water source may be a hot water source.
According to an aspect of the invention the water crusher may comprise an inlet leading to a conical element arranged internally in the water crusher When fluid flows from the liquid ring compressor which contains some liquid, this liquid will be broken up into smaller drops when it hits the conical element, forming a part of the gas leaving the liquid crusher. A large proportion of liquid is thereby obtained in the gas which is atomized in the space/the cargo holds.
According to an aspect a control unit may be mounted on the liquid ring
compressor, thereby enabling the liquid ring compressor to be switched from a position where it supplies and/or helps to supply fluid to/from the space/the cargo hold to a position where it supplies fluid to the cleaning fluid supply system and back again. In an embodiment the liquid ring compressor may be a water ring compressor which supplies air to the cleaning fluid supply system and otherwise creates a vacuum for assisting in loading and unloading processes.
According to an aspect the vessel may be a sea-going vessel such as for example a well boat, a ring net boat or a food products carrier.
According to an aspect of the invention a method is also provided for cleaning a cargo hold on a vessel, where a liquid ring compressor is arranged to supply fluid to a cleaning fluid supply system, where this fluid is conveyed to a liquid crusher, the gas from the liquid crusher is conveyed to and atomized in the cargo hold and pipes, and where during the atomizing process the necessary cleaning agent and/or other liquid is added.
Furthermore according to the invention there is also provided a use of a water ring compressor on a vessel in order to provide driving fluid in a cleaning process for cleaning cargo holds on the vessel.
The invention will now be explained by a non-limiting embodiment in some more detail, with reference to the attached figures, in which;
Fig. 1 illustrates a principle for a system according to the invention,
Fig. 2 illustrates an atomizing device for use in the cargo hold,
Fig. 3 illustrates a water crusher for placing downstream of the liquid ring compressor.
Fig. 1 illustrates a principle according to the present invention. In the cargo holds 1 , illustrated by dotted lines, one or more atomizing devices 4 are arranged. As illustrated, a cargo room may have one or three or another number of atomizing devices 4. The atomizing devices 4 are supplied with gas via lines leading from a gas outlet 31 of a liquid crusher 3, or as designated in other words, a separator 3. Upstream of the atomizing devices 4 there are provided regulating valves for the gas, in order to regulate to which cargo holds and the amount of gas to be admitted to the atomizing devices 4 in the cargo hold. In the atomizing devices 4 a supply line 5 is also connected for supply of cleaning agent or water from cleaning agent tank 6 or water tank 7 to the atomizing devices 4. Valves are provided for regulating the amount of cleaning agent into each atomizing device 4 and valves 9 for regulating the mixture ratio between the different cleaning agents. Furthermore, dosing units are also provided in the system to regulate the dosage of the different cleaning agents and the water. The water is preferably hot water. The liquid ring compressor 2 draws fluid from a suction line 14 from air. This fluid is admitted to the fluid inlet 30 in the liquid crusher 3. The liquid that collects in the bottom of the liquid crusher 3 is discharged therefrom through a liquid outlet 32 to a pump 15, to a cooler 16, which may be cooled, for example by seawater, where, when it is at the correct temperature as monitored by thermometer 17, the liquid can be used and returned to the liquid ring compressor if necessary. Valves in the system are controlled by a regulating unit 12 which controls the valves electrically, as indicated by the lines in the system. Valves 10 are also provided for controlling the orientation of the atomizing devices 4 in the cargo holds, thereby enabling all parts of the cargo holds to be flushed/cleaned/washed.
Fig. 2 illustrates a possible embodiment of an atomizing device as indicated in fig. 1. It is possible to employ other types of atomizing devices in the system in fig. 1. The atomizing device 4 or the mist valve has an inlet 40 for the gas that is passed from the liquid crusher arranged downstream of the liquid ring compressor. The cross sectional area is reduced from the inlet 40, whereupon a larger cross sectional area is again provided downstream thereof at the outlet 41. The outlet 41 may well be larger than the inlet 40 and between them is a portion with a cross sectional area which is smaller than both of them. This reduction in cross sectional area will increase the velocity of the gas admitted into the inlet, whereupon this increase in velocity will carry along cleaning agent from the supply line 5, which is arranged at the smallest cross sectional area. This portion of the atomizing device 4 is formed with an outer sleeve 44, a pipe element 45 mounted inside it and an innermost pipe element 42. These are arranged in close abutment to each other, outside each other. This innermost pipe element 42 has a plurality of milled grooves 43 in its outer surface. When this innermost pipe element 42 abuts against the outwardly arranged pipe element 45, channels will be formed in the longitudinal direction of the pipes 42, 45. These channels are connected to the supply line 5 and end in a portion of the atomizing device 4 where the gas has high velocity, with the result that it carries along cleaning agent. An ejector effect is thereby obtained in the atomizing device. From this portion with the smallest internal cross sectional area, the atomizing device 4 has a conical shape until the larger internal diameter at the outlet 41. Fig. 3 illustrates a possible embodiment of a liquid crusher. Other types of liquid crushers or separators may be employed in the system as described in connection with fig. 1. The illustrated liquid crusher has an inlet 30 in the upper part of a tank 37. This inlet 30 has a tubular form where it enters the tank 37 and leads to a conical crusher element 35. The crusher element may be perforated in order to crush water drops into even smaller water drops, thereby increasing the proportion of water in the gas which is discharged from the tank 37 via the gas outlet 31 in the upper surface of the tank 37. Between the inlet 30 and the crushing element 35 a protecting wall 36 is provided, in order to prevent excessively large water drops from being drawn directly from the inlet 30 to the outlet 32. Liquid separated in this process may be drained out through the liquid outlet 32 when the level meter indicates a certain amount of liquid in the tank 37.
The present invention has now been explained with reference to a non-limiting embodiment and some possible detail solutions. A person skilled in the art will appreciate that modifications and changes may be made to these examples which are within the scope of the invention as defined in the following claims.