GB2168261A

GB2168261A - Method of mixing materials and apparatus therefor

Info

Publication number: GB2168261A
Application number: GB08431721A
Authority: GB
Inventors: Paul Radmall
Original assignee: DOWTY GROUP SERVICES
Current assignee: DOWTY GROUP SERVICES
Priority date: 1984-12-15
Filing date: 1984-12-15
Publication date: 1986-06-18
Also published as: GB8431721D0; GB2168261B

Abstract

A method of mixing at least two materials, the first of which is contained in a plurality of capsules 5, comprising the introduction of the capsules into a flow conduit 1 at a position upstream of a filter device 2 contained in that conduit so that the capsules are carried by a second material 6 passing under pressure through conduit 1 in the direction towards device 2. Engagement of the capsules with device 2 causes them to rupture and to discharge their contents into the second material, so that mixing of the two materials takes place at least downstream of device 2. <IMAGE>

Description

SPECIFICATION Method of mixing materials and apparatus therefor This invention relates to a method of mixing materials and to apparatus therefor.

Hitherto, where for example a first material intended to act as a hardener is required to be introduced to a second or base material to effect subsequent setting of the mixture, this has been achieved by the use of injection or other suitable means which ensures that the first material passes in desired proportion into the second material as it flows towards, or reaches, a point of usage, mixing of the two materials then taking place to an adequate extent. In some cases the first material is contained in a capsule or capsules which are required to be pierced to release the contents thereof to enable the contents to so mix with the second material.

It is an object of this invention to provide an improved method of mixing materials, and apparatus therefor.

According to the invention a method of mixing at least two materials, the first of which is contained in a plurality of capsules, comprises the introduction of said capsules into a flow conduit at a position upstream of a filter device contained in that conduit so that said capsules are carried by a second material passing under pressure through said flow conduit in the direction towards said filter device, whereby engagement of said capsules with said filter device causes them to rupture and to discharge their contents into said second material, so that mixing of the two materials takes place at least downstream of said filter device.

Also according to this invention there is provided apparatus, for performing the method set out in the next-preceding paragraph, including a main flow conduit and a filter device contained in that conduit and adapted to rupture capsules, containing a first material, as they come into engagement therewith.

A secondary conduit may be provided which is connected with said main flow conduit upstream of said filter device and through which said capsules are permitted to pass into said main flow conduit.

Preferably said filter device includes a filter screen having a plurality of apertures of such shape and of such size that whilst preventing free passage of whole capsules through them to the downstream side of the device, their edges are sufficiently sharp as to effect rupturing of the capsules as, under the pressure applied thereto by a second material passing through said main flow conduit, they are forced into striking engagement with said edges of those apertures.

The apertures may be of circular shape and when capsules of circular cross-section are used their diameter is slightly larger than the diameter of said apertures.

The first material may be benzoyl peroxide and the second material may be a polyester resin.

By the invention the first said material in particular can be introduced in a readily-handleable manner and difficulties with leakage of that material are avoided as far as possible because the capsules are not ruptured until they reach the point at which their contents is really required to come into contact with the second material.

One way of carrying out the invention is described in detail below with reference to drawings which illustrate only one specific embodiment, in which: Figure 1 is a cross-sectional side elevation of a mixing apparatus in accordance with the invention, and Figure 2 is a cross-section taken along the line Il-Il on Figure 1.

In the drawings a main flow conduit 1 is provided with a filter device 2 which has a filter screen 3. A secondary conduit 4 connects into conduit 1 at a position upstream of the filter device.

Conduit 4 is connected to receive a first material, in this embodiment benzoyl peoxide, forming a hardener which is contained in a plurality of small capsules 5 of circular cross-section received from a suitable source (not shown). Conduit 1 is connected to receive a second material, in this embodiment a polyester resin 6 under pressure, also from a suitable source (not shown), this resin flowing along conduit 1 in the direction of the arrow.

The screen 3 is provided with a plurality of circular apertures 7 the diameter of each of which is slightly less than that of each capsule 5. Apertures 7 have sharp edges at their upstream ends.

It is required that a mixture of the contents within capsules 5 and the polyester resin 6 is passed from the mixing apparatus to a drilled hole (not shown), for example in a rock structure or in a concrete structure, and is there allowed to set hard to provide a means of locking an element, for example an anchor or roof bolt (also riot shown), occupying the drilled hole.

To this end capsules 5 delivered into conduit 4 are introduced into the resin 6 flowing under pressure through conduit 1 in the direction towards filter device 2 as indicated by the arrow, the number of capsules introduced being in a desired proportion to the volume of resin flowing. As the capsules enter the resin.they are carried along under the pressure in that resin towards the filter device.

On striking the sharp edges of apertures 7 the capsules are ruptured so that their contents are discharged into the resin then flowing through the filter device. Thus the benzoyl peroxide mixes with the resin at least downstream of the filter device and the mixture of these two materials passes from conduit 1 under the pressure applied thereto and is directed in suitable manner into the drilled hole in the rock structure or concrete structure, as the case may be, whereupon it sets due to the hardening effect of the benzoyl peroxide on the resin thus to lock the anchor or roof bolt in that structure.

The capsules 5 may, in some embodiments, be suspended when passing through conduit 4 in resin identical to the resin passing through the main flow conduit, or alternatively, may be urged through conduit 4 by a compressed gas, for example compressed air.

Although in the embodiment above described with reference to the drawings the filter device includes a screen having apertures provided therein, in other embodiments of the invention the filter device may be of somewhat different construction and include pointed elements presented towards the oncom ing- capsu les so that as the capsules engage the points of those elements they r rupture and discharge their contents into the resin.

Further, although in the embodiment above described with reference to the drawings the capsules are introduced through a secondary conduit into said main flow conduit, in alternative embodiments of the invention no such secondary conduit is provided, but instead the capsules containing-the first material are introduced directly into one end of the main flow conduit in suspension in the second material. In this case the capsules and the second material may be pressurized by external means so as to urge them together in the direction towards the filter device. The capsules and second material may be contained in a cartridge which is provided with a slave piston so that on pressurization of the slave piston the capsules and the second material are ejected together from the cartridge through a rupturablediaphragm or the like thereby then to pass through the conduit in the direction towards the filter device.

The invention is not limited to the use of benzoyl peroxide as the said first material and to the use of polyester resin as the said second material, as in other embodiments of the invention the first material may be in the form of any other suitable hardener and the second material may be any other suitable base material, for example an epoxy resin.

Claims

1. A method of mixing at least two materials, the first of which is contained in a plurality of capsules, comprising the introduction of said capsules into a flow conduit at a position upstream of a filter device contained in that conduit so that said capsules are carried by a second material passing under pressure through said flow conduit in the direction towards said filter device, whereby engagement of said capsules with said filter device causes them to rupture and to discharge their contents into said second material, so that mixing of the two materials takes place at least downstream of said filter device.

2. Apparatus, for performing the method set out in claim 1, including a main flow conduit and a filter device contained in that conduit and adapted to rupture capsules, containing a first material, as they come into engagement therewith.

3. Apparatus as claimed in claim 2, wherein a secondary conduit is provided which is connected with said main flow conduit upstream of said filter device and through which said capsules are permitted to pass into said main flow conduit.

4. Apparatus as claimed in either claim 2 or claim 3, wherein said filter device includes a filter screen having a plurality of apertures of such shape and of such size that whilst preventing free passage of whole capsules through them to the downstream side of the device, their edges are sufficiently sharp as to effect rupturing of the capsules as, under the pressure applied thereto by a second material passing through said main flow conduit, they are forced into striking engagement with said edges of those apertures.

5. Apparatus as claimed in claim 4, wherein said apertures are of circular shape and when capsules of circular cross-section are used their diameter is slightly largerthan the diameter of said apertures.

6. Apparatus as claimed in either claim 2 or claim 3, wherein said filter device includes pointed elements presented towards the oncoming capsules so that as the capsules engage the points of these elements they rupture and discharge their contents into the resin.

7. Apparatus as claimed in claim 2, wherein said capsules containing said first material are introduced directly into one end of said main flow conduit in suspension in the second material.

8. Apparatus as claimed in claim 7, wherein said capsules and said second material are contained in a cartridge which is provided with a slave piston so that on pressurization of said slave piston said capsules and said second material are ejected together from the cartridge through a rupturable diaphragm or the like thereby then to pass through the conduit in the direction towards the filter device.

9. A method as claimed in claim 1, wherein said first material is benzayl peroxide and the second material is a polyester resin.

10. A method of mixing at least two materials, substantially as hereinbefore described with reference to the accompanying drawings.

11. Apparatus, for performing a method of mixing at least two materials, substantially as hereinbefore described with reference to the accompanying drawings.