System, tool and method for cleaning the interior of a freight container

Abstract

A method for cleaning the interior of a freight container of ISO type having an access opening for receiving goods, wherein the method comprises: providing a cleaning tool comprising a framework, a robot movably connected to the framework and having a nozzle for supplying a cleaning medium including dry ice, and an actuating unit arranged to move the robot relative to the framework; gripping the framework of the tool with a truck designed for gripping and carrying freight containers of ISO type; driving the truck carrying the tool to the container to be cleaned; moving the robot into an interior of the container by means of the actuating unit; and moving the nozzle by means of the robot along a programmed cleaning path while cleaning the interior of the container by means of dry ice blasting.

Claims

1. A method for cleaning the interior of a freight container of ISO type having an access opening for receiving goods, wherein the method comprises: providing a cleaning tool comprising a framework, a robot movably connected to the framework and having a nozzle for supplying a cleaning medium including dry ice, and an actuating unit arranged to move the robot relative to the framework; gripping the framework of the tool with a truck designed for gripping and carrying freight containers of ISO type; driving the truck carrying the tool to the container to be cleaned; moving the robot into an interior of the container by means of the actuating unit; and moving the nozzle by means of the robot along a programmed cleaning path while cleaning the interior of the container by means of dry ice blasting.

2. The method of claim 1 wherein the framework comprises a housing enclosing the robot and the actuating unit, the housing having an opening sized to attach to the access opening of the container, the truck moves the tool to a position in which the opening of the housing is facing the opening of the container, and the method further comprises attaching the opening of the housing to the opening of the container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained more closely by the description of different embodiments of the invention and with reference to the appended figures.

(2) FIG. 1 shows a tool for cleaning the interior of a freight container according to an embodiment of the invention in a perspective view seen slightly from above.

(3) FIG. 2 shows a perspective view of the tool shown in FIG. 1 seen slightly from below.

(4) FIG. 3 shows a tool for cleaning the interior of a freight container according to another embodiment of the invention.

(5) FIG. 4 shows an example of means for attaching the opening of the housing to the opening of container.

(6) FIG. 5 shows a system for cleaning the interior of freight containers according to an embodiment of the invention.

(7) FIG. 6 shows a truck moving the cleaning tool to the container to be cleaned.

(8) FIG. 7 shows the tool during cleaning of the container.

DETAILED DESCRIPTION

(9) FIGS. 1 and 2 show a tool 1 for cleaning the interior of a freight container according to an embodiment of the invention. The tool 1 comprises a framework 2 having a size and design that allows a truck adapted for gripping and carrying freight containers of ISO type to grip and carry the tool. Preferably, the external size of the framework should correspond to the outer size of an ISO container. It is particular important that the width of the tool is not much larger than the width of an ISO container. Further, the framework should be designed so that it is possible for the truck to grip the container with a standardized gripping tool. The tool further comprises a robot 3 movably connected to the framework 2 and provided with a nozzle 4 for spurting dry ice. The robot and the nozzle are adapted to clean the interior of the container by means of dry ice blasting.

(10) In this example, the framework 2 is provided with a rail 8 arranged in the ceiling. Alternatively, the rail can be mounted on the floor of the framework. The tool also includes an actuating unit 6 arranged to move the robot between the interior of the framework and the interior of the container to be cleaned. In this example, the actuating unit 6 includes an elongated holding device 9 connected to the robot and arranged movable relative the beam 8. The actuating unit further includes a motor 10 for driving the motion of the robot relative to the framework. The holding device 9 has a length that essentially corresponds to the length of the interior of the housing 2. This is advantageous since the length of the housing corresponds to the length of the container to be cleaned, and accordingly the robot can reach the inner part of the container during the cleaning. The holding device 9 is provided with a counter weight 11 to compensate for the weight of the robot. The holding device 9 carrying the robot 3 is arranged movable along the longitudinal axis of the housing 2.

(11) In this example, the framework 2 is designed as an elongated housing enclosing the robot 3 and the actuating unit 6. The housing is provided with an opening 12 in one of its short ends and has a size such that the robot can be moved between the outside and the interior of the housing through the opening. The opening 12 is provided with a door 14. The door can be opened 270 degrees and accordingly allows a leak proof connection to the opening of the container. The housing is provided with means 15 for receiving grippers of a gripping tool of the truck, and for attaching the housing to the gripping tool. In this embodiment the means 15 is a set of three holes, each set of holes arranged in one corner of the roof of the housing. The gripping tool of the truck includes correspondingly arranged grippers with a hook. During the gripping, the hooks are inserted into the holes and the grippers are turned so that the hooks are locked in the holes. In this embodiment, the housing 2 is provided with an electrical connector 16 for connection to a power supply cable. The power is, for example, supplied from the truck to the tool. In this embodiment the housing is made of an ISO container, for example, with a length of 20 ft. or 40 ft. Such an ISO container has a rectangular cross section and an opening with a rectangular cross section.

(12) In this example the robot 3 is a traditional industrial robot having three main axes and three wrist axis. A stationary foot, usually referred to as the base of the robot, supports a stand which is rotatable about a first axis. The stand supports a first arm which is rotatable about a second axis. The first arm supports a second arm which is rotatable about a third axis. The second arm supports a wrist which is rotatable about a fourth, fifth and a sixth axis. The wrist supports the nozzle 4. The movement of the robot 3 is controlled by robot controller. Preferably, the robot controller is located inside the housing 2. Preferably, the actuating unit 6, and accordingly the horizontal movements of the robot 3 relative housing 2 is also controlled by the robot controller.

(13) FIG. 3 shows a cleaning tool 20 according to another embodiment of the invention and a container 24 to be cleaned. Elements corresponding to the ones of the embodiment shown in FIGS. 1 and 2 are given in the same reference numbers as the corresponding elements of that embodiment. The tool 20 includes a robot 3 provided with a nozzle 4 adapted for dry ice blasting and a housing 2. The actuating unit 6 is arranged to move the robot 3 between the interior of the housing 2 and the interior of the container 24. FIG. 3 shows the robot in its cleaning position inside the container while cleaning the container by means of dry-ice blasting. In this embodiment, the holding device 9 is provided with a support wheel 26 for facilitating the movements of the robot between the container and the housing. However, it is also possible to have more than one support wheel.

(14) The robot 3 is controlled by a robot controller 30 located inside the housing 2. The robot controller 30 is a traditional robot controller and includes software for controlling the movements of the robot and accordingly the movements of the nozzle 4. The roof 22 of the housing 2 is designed as an interface to a gripping device of a truck adapted for gripping and carrying ISO containers. In this embodiment, the tool comprises a power unit 32 for providing power to the robot 3, the motor 10 of the actuating unit, and to a dry ice producing unit 34. The power unit 32 is located inside the housing 2. The power unit 32 is, for example, a battery, fuel cell, or a power plant producing electricity based on a fossil fuel. In this embodiment the power unit is a power plant producing electricity based on diesel.

(15) In this embodiment, the tool further comprises a dry ice producing unit 34 arranged to produce dry ice, i.e. frozen carbon dioxide, and to provide the nozzle with the dry ice. The dry ice producing unit 34 is located inside the housing 2. The dry ice producing unit 34 comprises storage for CO.sub.2. The dry ice producing unit further includes a compressor 36 for delivering the dry ice with super sonic speed to the walls of the container to be cleaned. In this example, the power unit 32 includes a diesel engine. The diesel engine produces waste gases including carbon dioxide. The carbon dioxide is separated from the waste gases and is led to the dry ice producing unit 34 via a duct 38. The dry ice producing unit is configured to receive the carbon dioxide from the power unit and to use the carbon dioxide for producing dry ice in addition to the stored CO.sub.2. Accordingly, the CO.sub.2 from diesel engine is reused in the dry ice producing unit.

(16) The dry ice produced by the dry ice producing unit 34 is transferred to the nozzle 4 by means of a flexible tube (not shown). The electrical power produced by the power unit 32 is supplied to the robot controller 30, to the motor 10 of the actuating unit, the compressor 32 and to the dry ice producing unit 34. The robot controller 30 is connected to the robot 3 and provides the robot with power. Alternatively, it is possible to use prefabricated dry ice.

(17) The tool further comprises a ventilation duct 40 provided with a fan 41 for transporting waste products, originating from the dry ice cleaning, from the container 24 to the tool 20. The ventilation duct 40 has an inlet 44 arranged in the opening 12 of the housing and an outlet 46. The outlet 46 is, for example, connected to a storage unit 48, such as a removable bag, for retaining the waste products. The duct and the bag are located inside the housing. The duct 40 is, for example, arranged by installation of a second floor 42 in the housing of the tool. The opening of the container 24 as well as of the opening 12 of the housing 2 is provided with bellows 54a-b to allow the openings to be sealingly connected to each other. The tool comprises means 50a-b for attaching the opening of the housing 2 to the opening of the container 24. The container is provided with corresponding attachment means 52a-b. FIG. 4 shows an example of the attachment means in more detail. In this example the attachment means of the tool includes a rotatable gripping arm 50a arranged movable relative the housing of the tool, and the container 24 is provided with space having an elongated opening 52a adapted for receiving the rotatable gripping arm. This is a common type of attachment means for ISO containers.

(18) FIGS. 5-7 show a system for cleaning the interior of ISO containers 24. The containers 24 have access openings for receiving goods. The system comprises a cleaning tool 20 as described with reference to FIGS. 1 and 2. The system further comprises a truck 60 specially designed for gripping and carrying freight containers of ISO type. The truck 60 includes a base structure provided with wheels and a motor. The base structure is provided with two pairs of upwardly protruding elements: a pair of front elements 64a and a pair of rear elements 64b. The distance between the elements of the pair correspond to, or is a little bit larger than the width of the containers in order to allow the front and rear elements 64a-b to receive the container 24. The truck is further provided with a gripping tool 62. The gripping tool 62 is arranged vertically movable relative the elements 64a-b and accordingly relative the ground. The gripper tool 62 is provided with at least four grippers 65 designed to grip and attach to the container 24. The grippers 65 are, for example, of the same type as shown in FIG. 4. The grippers 65 includes a rotatable gripping arm arranged movable relative the gripping tool, and the roof of the containers 24 and the housing 2 of the cleaning tool is provided with space having an elongated opening 15 adapted for receiving the rotatable gripping arm. This truck 60 is designed for gripping and moving ISO containers 24. According to the invention, the same truck 60 is also used for gripping and transportation of the cleaning tool 1.

(19) FIG. 5 shows the truck 60 moving towards the cleaning tool 1. When the truck has reached the cleaning tool, the gripping tool 62 is moved so that it is above the roof of the cleaning tool. The gripping tool is lowered until the gripping arms of grippers can be inserted into the openings 15 of the housing of the cleaning tool. When the gripping arms have been inserted in the openings, the gripping arms are rotated about 90 degrees and the grippers are locked. When the cleaning tool has been attached to gripping tool of the truck and raised from the ground, the truck moves the cleaning tool in a direction towards the container 24 to be cleaned, as shown in FIG. 6. The door of the container to be cleaned and the door of the housing of the cleaning tool are opened. The truck moves the cleaning tool so that the opening of the cleaning tool is facing the opening of the container 24. Thereafter, the truck moves the cleaning tool into contact with the container and the openings are attached to each other. The robot is moved by means of the actuating unit from the interior of the cleaning tool to the interior of the container 24. When the robot is inside the container 24 the robot begins the cleaning by dry ice blaster of the interior of the container, as shown in FIG. 7. The robot is moved according to a preprogrammed path suitable for carrying out cleaning of the interior of the container. During the cleaning, the actuating unit moves the robot along the length axes of the container so that the entire container is cleaned.

(20) When the cleaning is finished the robot is moved back into the interior of the cleaning tool 20 and the truck 60 either moves the cleaning tool to the next container to be cleaned, or if all containers have been cleaned, moves the cleaning tool back to a storage position of the tool. When the cleaning of the containers has been finished the same truck can be used for moving the cleaned containers to a vehicle such as a train or a ship for further transportation.

(21) The present invention is not limited to the embodiments disclosed but may be varied and modified within the scope of the following claims. For example, in the embodiments described above the housing is provided with walls enclosing the robot and thereby achieving suitable conditions for the robot regarding damp and temperature. In an alternative embodiment it is possible to have a framework without walls, or with only a few walls, or with only a roof, but no walls. However, such a construction is only suitable to use indoors. The truck disclosed in FIGS. 5-7 is a straddle carrier type of truck. However, the truck can be of various types, for example, container handlers, reach stackers, forklift trucks and automatic stacking cranes.