GB2044160A

GB2044160A - A bag adapted for the handling of a filtering element or filter unit

Info

Publication number: GB2044160A
Application number: GB7909818A
Authority: GB
Original assignee: Marshall D A G
Current assignee: Marshall D A G
Priority date: 1979-03-20
Filing date: 1979-03-20
Publication date: 1980-10-15

Abstract

The invention relates to a transparent, flexible, synthetic plastics bag (10) adapted to contain a filter element or filter unit (20) so that the latter can be inserted into or removed from a filter casing or duct (22) while being contained in the bag, in which the bag has a neck portion (32) which is capable of being removably secured in an air-tight manner on to a part (34) of the casing, and gloves or glove portions (18) are provided in, or are formed in, the wall of the bag to permit handles (26) on the filter element or unit to be grasped. <IMAGE>

Description

SPECIFICATION A bag adapted to contain a filtering element or filter unit This invention relates to a bag adapted to contain a filter element or filter unit.

In a number of prior British Patents and Patent Applications I have described various filters for filtering air and other gases. Some of these filters are designed to filter out toxic gases or other toxic substances which would otherwise be very injurious to health. For example, this is the case with filters used in nuclear power plants.

It will therefore be appreciated that, where a filter has been used to filter out toxic gases or other toxic substances, it will need to be handled with great care when the time comes for it to be replaced. In order to meet the stringent safety requirements laid down in nuclear installations and other plants where such toxic substances are encountered, the filter to be replaced should not be handled directly by anyof the personnel involved in its removal and it should be completely enclosed at all stages during its removal from a filter casing or duct where it is installed.

With this need in view, the present invention is directed to a transparent, flexible, synthetic plastics bag adapted to contain a filter element or filter unit so that the latter can be inserted into or removed from a filter casing or duct while being contained in the bag, in which the bag has a neck portion which is capable of being removably secured in an air-tight manner on to a part of the casing, and gloves or glove portions are provided in, or are formed in, the wall of the bag to permit handles on the filter element or unit to be grasped.

By means of the invention it thus becomes possible for a filter element or unit which is contaminated with toxic gases or other toxic substances as a result of its use in a filter casing or duct to be removed from the latter while being totally enclosed by the bag, there being provision for the bag to be completely sealed once the filter element or unit has been brought completely within the bag from the filter casing or duct.

In order that the invention may be thoroughly understood, an example of a bag in accordance with it will now be described with reference to the accompanying drawings, in which Figure 1 is a perspective view from above of the bag; Figure 2 is another perspective view from above of a filter unit lying just outside a filter casing or duct in which it is normally housed during use; and Figures 3-9 are diagrammatic plan views illustrating different stages during the insertion and removal of a filter unit and out of the filter casing or duct using the bag shown in Figure 1.

The bag 10 shown in Figure 1 is made of a transparent, flexible, synthetic plastics material such as heavy-duty polyethylene having a thicknes of 0.2 mm. Alternatively, the bag can be made of a laminate of polyethylene PVDC. It is to be understood that these two synthetic plastics materials are given by way of example only and that many other such materials could be used instead.

As will be seen from Figure 1, the bag 10 is generally of rectangular shape. Projecting into it from three of its sides 12, 14 and 16 are six gloves or glove portions 18 provided in, orformed in, the wall of the bag. These gloves can be made of polyethylene of greater thickness than the wall of the bag itself and are preferably heat welded into the bag after appropriate holes have been cut in the wall of the bag. It is however equally possible for the gloves or glove portions to be formed integrally in the bag.

Figure 2 illustrates a typical filter unit 20 which is inserted into a filter casing or duct 22 through an opening 24 in the latter. The filter unit 20 is of generally rectangular shape and it will be noticed that it has handles 26. Only two sides of the filter unit are shown as having such handles but in fact the side opposite the side 28 is similarly provided with two handles 26 as well. In otherwords,there are six handles on the filter unit, there being two handles on each of three sides. The internal construction of the filter unit 20 is not of importance from the point of view of the present invention apart from the fact that the filter unit is designed to absorb toxic gases and substances such as those found in nuclear power plants and in industrial chemical plants.A particular example of such a filter unit is shown in my co-pending Patent Application No.78.29879 filed on 14th July, 1978.

Figure 3 illustrates the first stage in inserting the filter unit 20 into the filter casing or duct 22 through the opening 24. The filter unit is placed within the bag so that its handles 26 can then be grasped through the gloves or glove portions 18. The filter units will frequently be sufficiently heavy for three men to be needed to handle them so that there will be one man at each of the three sides of the bag provided with the gloves or glove portions 18. With the filter unit 20 being held stationary within the bag by those three men, a nylon cord 30 which is preferably integral with the neck portion 32 of the bag is tightened to pull the said neck portion into an air-tight seal with respect to an annular groove 34 in the mouth part of the filter casing or duct 22.

Figure 4 shows the filter unit 20 having been moved into its normal operating position within the filter casing or duct 22. Once that operation has been completed a double heat seal is formed at the part 36 of the bag so as to seal offthe inside of the filter casing or duct 20 from the outside. As will be seen from Figure 4, the nylon cord 30 remains tightly in position.

When it is desired to remove the filter unit 20 from the filter casing or duct 22 then another bag 10' is fitted on to the mouth portion of the filter casing or duct as shown in Figure 5 by tightening its nylon cord 38 onto a second annular groove 40 in the mouth portion of the filter casing or duct 22. Once that has been done, the remaining portion 42 of the earlier bag 10 is released by cutting or otherwise removing the nylon cord 30. The remains 42 of the earlier bag are then placed out of the way within the second bag 10' to permit the filter unit 20 to be brought into the right-hand position shown in Figure 5. As with the insertion of the filter unit illustrated in Figure 3, the removal of the filter unit is accomplished by three men grasping its three handles 26 through the gloves or glove portions 18.For the sake of simplicity, the gloves or glove portions 18 have been omitted in Figures 5-9 of the drawings.

As shown in Figure 6 which illustrates the fourth stage of the insertion and removal procedure, the filter unit 20 which has been removed is now ready for disposal. A double heat seal is formed at the part 44 of the second bag 10' so that the removed filter 20 is now totally enclosed and can be taken away to a safe place where it will be incinerated or otherwise disposed of. This leaves a small portion 46 of the bag 10' still fitted on to the mouth portion of the filter casing or duct 22.

Figure 7 illustrates the insertion of a new filter unit 20' to replace that which has just been removed.

Prior to the insertion of the new filter unit 20' into the filter casing or duct 22, the remains 46 of the bag 10' are moved from the groove 40 on the mouth portion of the filter casing or duct 22 to the groove 32. That then permits a further bag 10" to be placed round the new filter unit 20' as shown in Figure 8 and to have its neck portion secured to the groove 40 by a nylon cord 48. Once the neck portion of the new bag 10" has been secured in the groove 40 the remains 46 of the bag 10' can then be placed out of the way within the bag 10". The new filter unit 20' is now therefore ready for insertion into the filter casing or duct 22 as shown in Figure 9. A double heat seal 50 is then formed on the bag 20".

It will therefore be seen that the present invention provides a bag by which a filter element of filter unit can be inserted into or removed from a filter casing or duct without there being any risk of contamination from toxic gases or substances within the filter casing or duct or within the filter element or unit once it has been used.

Claims

1. A transparent, flexible, synthetic plastics bag adapted to contain a filter element or filter unit so that the latter can be inserted into or removed from a filter casing or duct while being contained in the bag, in which the bag has a neck portion which is capable of being removably secured in an air-tight manner on to a part of the casing, and gloves or glove portions are provided in, or are formed in, the wall of the bag to permit handles on the filter element or unit to be grasped.

2. A bag according to claim 1, in which its shape and size is such that it can be completely sealed once the filter element or unit has been brought completely within the bag from the filter casing or duct.

3. A bag according to claim 1 or claim 2 which is made of heavy-duty polyethylene having a thickness of 0.2 mm. or above, or of a laminate of polyethylene with PVDC.

4. A bag according to any one of claims 1-3 having a generally rectangular shape apart from its neck opening, there being a plurality of gloves or glove portions provided in, or formed in, at least three walls of the bag.

5. A bag according to any preceding claim, in which the glove or glove portions are made of polyethylene of greater thickness than the wall of the bag itself and are heat welded into the bag after appropriate holes have been cut in the wall of the bag or are formed integrally in the bag.

6. A bag according to claim 1 substantially as described herein with reference to the accompanying drawings.

7. A method of using a bag according to claim 1 for the purpose of inserting a filter element or unit into a filter casing orductthrough a mouth opening in the latter, which method comprises placing the unit or element within the bag so that handles on the unit or element can be grasped through the gloves or glove portions of the bag, and holding the unit or element stationary within the bag while a cord which is integral with or adjacent the neck portion of the bag is tightened to pull the said neck portion into an air-tight seal with respect to an annular groove in the mouth part of the filter casing or duct.

8. A method according to claim 7, in which, once the said operation has been completed, a double heat seal is formed at an intermediate part of the bag so as to seal off the inside of the filter casing or duct from the outside.

9. A method of using a bag according to claim 1 for the purpose of removing a filter unit or element from a filter casing or duct, which method comprises fitting another bag to the mouth portion of the filter casing or duct by tightening a cord on to a second annular groove in the mouth portion of the filter casing or duct, releasing the remaining portion of a first bag used to insert the unit or element into the casing or duct by cutting or otherwise removing its cord, removing the remains of the first bag into the second bag, and moving the filter unit or element into the second bag by grasping handles on the unit or element through the gloves or glove portions of the bag.

10. A method according to claim 9, in which, after the filter unit or element has been removed from the casing or duct, a double heat seal is formed at an intermediate part of the second bag so that the removed filter is now totally enclosed and can be taken away to a safe place for incineration or other form of disposal.

11. A method according to claim 10 for the insertion of a new filter unit or element to replace that which has been removed, which method comprises moving the remains ofthe second bag from the second groove on the mouth portion of the filter casing or duct to the first groove, placing a further bag round the new filter unit or element and securing the neck portion of the said further bag to the said second groove by a cord, moving the remains of the second bag out of the way within the said further bag, and inserting the new filter unit or element into the filter casing or duct, whereupon a double heat seal is formed on the further bag at an intermediate portion thereof.