Improvements in or relating to protective apparatus used in the handling of harmful substances

Abstract

 In a method for the removal of harmful material 28 from an object 26, the object 26 is surrounded by an enclosure 10, the harmful material 28 is removed from the object and deposited within the enclosure 10, foam is introduced into the enclosure to cover the removed material, and the enclosure is removed from about the object.

Description

[0001] In recent years, realisation of the danger to health posed by harmful materials, for example, asbestos, has made it desirable to remove such materials from sites where they have been used. In the past, asbestos has been widely used for lagging pipes. The removal of lagging which is frequently old produces a great quantity of asbestos fibres, commonly referred to as dust, and constitutes a particular hazard to persons involved in the operation, or in the vicinity.

[0002] In British Patent No. 1567260, there were proposed a method and apparatus for stripping lagging from a length of pipe, in which the length of pipe and the removed material were substantially isolated from the operator and from the surroundings. In operation of the previous method, there was a tendency for dust particles to remain suspended in the air for prolonged periods and, whereas the bulk of the material could be safely removed using the method, a small proportion of the dust remained suspended in air. Because the inhalation of small airborne particles poses a substantial threat to health, there remains a need to improve the procedure to reduce the incidence of airborne particles.

[0003] According to one aspect of the invention, a method of removing material from an object comprises the steps of surrounding the object with an enclosure, sealing the object in the enclosure, removing the material from the object and depositing the material within the enclosure, introducing a foam into the enclosure to cover the removed material and removing the enclosure from about the object.

[0004] The object is sealed within the enclosure in order to prevent the stripped material, or dust therefrom, escaping from the enclosure, and accordingly any form of closure which achieves this object may be used to seal the object within the enclosure. The material to be stripped from the object may be inside the object, on its surface, or both.

[0005] In another aspect, the present invention relates to improvements in the method and apparatus described in British Patent No. 1567260, which afford increased protection for the operator or other persons in the vicinity from dust produced in the removal of lagging from a length of pipe, comprising the injection of foam into the apparatus before removal of the apparatus from the length of pipe. The injection of foam serves the dual purposes of reducing the dust content of the atmosphere within the apparatus,.and of eliminating the formation of further dust from the removed material. t Foam has better properties in this respect than water.

[0006] Thus, in a preferred form of the present invention, a method of stripping lagging from a length of pipe comprises a first step of placing about the length of pipe the upper end portion of a bag, preferably of plastics sheet material, which is transparent in at least the regions adjacent to the pipe, the bag enclosing said length, the said bag having apertures or sleeve portions through which the operator may insert his hands into the space within the bag, the bag further having a foam inlet, preferably at a point which in use will be above the maximum surface level of the stripped lagging, and substantially sealing the bag with respect to the ends of said length, a second step of stripping the lagging from the pipe, the stripped lagging falling into the bottom of the bag, and a third step of injecting foam into the bag through the foam inlet onto the stripped lagging. Preferably the above-mentioned sleeve portions may terminate in gloves or mittens. The sleeve portions may, however, be open sleeves, in which case the operator using the apparatus would normally wear gloves or gauntlets. Similarly, an operator using a bag having apertures instead of sleeve portions would normally wear gloves or gauntlets.

[0007] According to a further aspect of the invention, a protective apparatus for the stripping of lagging from a length of pipe comprises a bag having one end closed and its other end capable of being detachably secured about a length of lagged pipe, forming a seal with opposite ends of the said length, the said bag being made from plastics sheet material which is transparent in at least the regions thereof to be adjacent to the pipe and having apertures or sleeve portions through which an operator may insert his hands into the interior of the bag for work on the pipe, a foam inlet through which foam may be injected into the bag, and further comprising means for supplying or producing foam.

[0008] It will of course be appreciated that the foam inlet is preferably at a point which is above the maximum surface level of the stripped lagging, that is in the upper portion of the bag.

[0009] Preferably the foam used in the invention is of a type formulated from at least one highly foaming anionic hydrocarbon surfactant, at least one solvent and at least one foam stabiliser, although in principle any flexible foam may be used, for example a mechanically or chemically produced foam of the type used in fire fighting. A foam typical of the type preferred for use in the invention has the following properties:



effect of freeze/thaw : no performance loss.

[0010] An Example of a foam suitable for use in the invention is EXTOL.

[0011] The foam inlet is preferably capable of connexion to a foam supply.

[0012] The injection of foam into the apparatus may, if desired, be controlled by a valve, tap, or other means incorporated into the foam inlet.

[0013] In a preferred form of the invention the bag has means for securing the front and back walls of the bag together at a location between the sleeve portions and the end of the bag where the removed lagging is kept.

[0014] In using the apparatus, the operator positions the bag about the object and strips off the material to be removed. When this has been done the operator opens the foam inlet to allow foam to be injected into the bag. When the reauired quantity of foam has entered, the operator shuts the foam inlet and removes the bag from the pipe.

[0015] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a front view of a protective apparatus according to the invention, and

Figure 2 shows a cross-sectional view of the apparatus, on the line II-II of Figure 1.

[0016] Referring to the drawings, the protective apparatus 10 is made from transparent plastics sheet material and all its seams are welded. The apparatus is in the form of a bag with front and back walls 12, 14, the lower portion 20 of the bag acting as a receptacle for the stripped material. In its upper portion, the bag has front and back flaps 22, 24 which, in use, are placed about a length of a pipe 26 from which lagging 28 is to be removed. The edges of the flaps 22, 24 meet when the flaps are so placed about the pipe, and they have formed integrally with them or welded to them the components of a sliding clasp fastener 30, operated by clasp 32, to form a seal between the two flaps. The flaps 22, 24 have lateral extensions 34, 36 beyond the bag to cover adjoining lengths of the lagged pipe, thus forming a seal with opposite ends of the first-mentioned length.

[0017] Two sleeve portions 38, 40 are secured to the front wall 12 of the bag, in its upper portion, at apertures 42, 44, and extend into the interior of the bag. The two sleeve portions 38, 40 terminate in respective mitten portions 46, 48, with respective elasticated cuffs 50, 52, to grip the operator's wrists. A further, smaller aperture 54 is provided in the front wall 12 between the two apertures 42, 44. A short, open-ended sleeve 56 extends into the bag from the aperture 54, and is provided with a tap 59 which may be used to control the injection of foam into the bag.

[0018] Two strips 60, 62 of a Velcro (Trade Mark) fastener are secured to the inner faces of the front and back walls 12, 14, respectively, below the apertures 42, 44, in order that the lower portion 20 of the bag can be sealed when the lagging 28 has been removed from the pipe 26.

[0019] When the protective apparatus is to be used, with the clasp fastener 30 unfastened, the two flaps 22, 24 are placed around the length of lagged pipe 26 and are then fastened together by sliding the clasp 32. The flap extensions 34, 36 may be secured about the pipe by string or laces 76, 78 or other convenient means. The operator then inserts his hands and arms into the mitten and sleeve portions 46, 38 and 48, 40 and works on the lagging, using handtools as necessary. With the Velcro fastener 60, 62 unfastened, the displaced lagging falls into the lower portion 28 of the bag, which may if necessary be supported on a table or other flat surface or in the angle of a V-shaped supporting surface. When the length of pipe has been stripped of lagging, or even during the actual stripping operation, the operator may introduce foam from a foam supply through the aperture 54 and the sleeve 56 to damp down dust within the bag, the introduction of foam being controlled by the tap 59. When the particular length of pipe has been stripped, the two Velcro strips 60, 62 are pressed together to seal the lagging spoil in the lower portion 20 of the bag. The bag may then be removed from the pipe by unfastening the clasp fastener 30, and may be placed bodily within an outer bag for disposal in accordance with existing regulations.

[0020] It will of course be understood that the foam to be used in accordance with the invention will be a foam which will remain stable for a length of time which is sufficient to allow safe removal and disposal of the apparatus and the stripped material contained therein.

[0021] The removal of lagging carried out as described herein reduces the exposure of the operator to harmful dust and hence increases the safety of these operations.

Claims

1. A method of removing material from an object, comprising the steps of surrounding the object with an enclosure, sealing the object within the enclosure, removing the material from the object and depositing the material within the enclosure, introducing a foam into the enclosure to cover the removed material and removing the enclosure from the object.

2. A method of removing material from an object as claimed in claim 1, wherein the object is a length of pipe and wherein the enclosure comprises a bag, the upper end portion of the bag being placed about and so enclosing the length of pipe, the said upper end portion of the bag being transparent in at least the regions thereof to be adjacent to the pipe, the bag having apertures or sleeve portions through which the operator may insert his hands into the space within the bag, the bag further having a foam inlet at a point which in use will be above the maximum surface level of the stripped lagging, the bag being substantially sealed with respect to the ends of the said length, the material being stripped from the pipe, the stripped material falling into the bottom of the bag and foam being injected into the bag through the foam inlet onto the stripped lagging.

3. A method of removing material from an object as claimed in claim 1 or claim 2, wherein the foam is formed from a mixture of at least one highly foaming anionic hydrocarbon surfactant, at least one solvent and at least one foam stabiliser.

4. A protective apparatus for the stripping of lagging from a length of pipe, comprising a bag having one end closed and the other end capable of being detachably secured about a length of lagged pipe, forming a seal with opposite ends of the said length, the said bag being made from plastics sheet material which is transparent in at least the regions thereof to be adjacent to the pipe and having apertures or sleeve portions through which an operator may insert his hands into the interior of the bag for work on the pipe, a foam inlet through which foam may be injected into the bag, and further comprising means for supplying or producing foam.

5. A protective apparatus as claimed in claim 4, wherein the foam inlet is at a point on the upper part of the bag which is so located that it will be above the maximum surface level of the stripped lagging in the bag in use of the apparatus.

6. A protective apparatus as claimed in claim 4 or claim 5, wherein the bag has means for securing the front and back walls of the bag together at a location between the sleeve portions and the closed end of the bag.

7. A protective apparatus as claimed in any one of claims 4 to 6, which has sleeve portions, and wherein the sleeve portions terminate in gloves or mittens.

8. A protective apparatus as claimed in any one of claims 4 to 7, wherein the foam inlet has incorporated therein a control means for control of the injection of foam.

9. A protective apparatus as claimed in claim 8, wherein the control means comprises a valve or tap.

10. A kit of parts comprising (i) a protective apparatus for the stripping of lagging from a length of pipe, comprising a bag having one end closed and the other end capable of being detachably secured about a length of lagged pipe, forming a seal with opposite ends of the said length, the said bag being made from plastics sheet material which is transparent in at least the regions thereof to be adjacent to the pipe and having apertures or sleeve portions through which an operator may insert his hands into the interior of the bag for work on the pipe and a foam inlet through which foam may be injected into the bag and (ii) means for supplying foam to the foam inlet.

Drawing