EP2390008A1

EP2390008A1 - An injector

Info

Publication number: EP2390008A1
Application number: EP11250561A
Authority: EP
Inventors: Ian Tebb
Original assignee: Polypearl Ltd
Current assignee: Polypearl Ltd
Priority date: 2010-05-28
Filing date: 2011-05-27
Publication date: 2011-11-30
Also published as: GB201008945D0; GB2480677A

Abstract

In the filed of injectors for injecting a particulate insulant material and a binding agent into a cavity there is a need for an improved injector that is able to maintain a uniform flow of insulant material and binding agent into a cavity to be injected.

An injector (50) comprises a hollow injector body (52) which has insulant and binding agent inlets (54, 56). The injector body (52) also includes a carrier fluid inlet (58) that is located downstream of the insulant material and binding agent inlets (54, 56). The carrier fluid inlet (58), in use, generates a low pressure region (82) in an interior (66) of the injector body (52) to draw insulant material (60) and binding agent (62) into the injector body (52).

Description

This invention relates to an injector, and in particular to an injector for injecting a particulate insulant material and a binding agent into a cavity.
It is known to mix a particulate insulant material and a binding agent before injecting into a cavity, e.g. a cavity in a wall of a building in order to reduce the thermal transmittance of the wall.
A conventional injector 10 for injecting such a mixture into a cavity wall is shown in Figure 1.
The known injector 10 includes a hollow injector body 12 having insulant material, binding agent and carrier fluid inlets 14, 16, 18 which converge in a mixing chamber 20 within the injector body 12.
The injector also includes a handle 22 extending from the injector body 12 that is intended to promote use of the injector in a desired orientation with the handle 22 extending downwards, as shown in Figure 1.
One drawback with the conventional injector 10 is that operatives have a tendency to use the bulky hose 24 supplying insulant material to the injector 10 as a makeshift handle, with the designated handle 22 extending upwards, since the conventional injector 10 is more easily held in this orientation.
Under such circumstances, i.e. with the insulant material hose 24 extending downwards, the binding agent has a tendency to drip into the hose 24. Dripping of the binding agent into the hose 24 causes the accumulation of insulant material at the insulant material inlet 14. This reduces the flow of insulant material into the injector 10, and can even block the insulant material inlet 14. Fouling of the insulant material inlet 14 in this way leads to an inconsistent flow of mixed insulant material and binding agent from the injector 10 which, in turn, causes an injected wall to exhibit an inconsistent reduction in thermal transmittance.
It is also difficult for an operative to remove any such accumulated insulant material and binding agent from the insulant material inlet 14, and so the aforementioned difficulties are not easily rectified.
There is, therefore, a need for an improved injector that is able to maintain a uniform flow of insulant material and binding agent into a cavity to be injected.
According to a first aspect of the invention there is provided an injector, for injecting a particulate insulant material and a binding agent into a cavity, the injector comprising a hollow injector body having insulant material and binding agent inlets and a carrier fluid inlet located downstream of the insulant material and binding agent inlets, the carrier fluid inlet in use generating a low pressure region in an interior of the injector body to draw insulant material and binding agent into the injector body.
Generating a low pressure region that draws the binding agent into the injector body reduces the likelihood of the binding agent fouling the insulant material inlet, irrespective of the orientation of the injector. This helps to keep the injector body and its inlets free from any obstruction and so maintain a uniform and constant flow of insulant material and binding agent into a cavity.
Preferably the carrier fluid inlet includes a carrier fluid manifold arranged in fluid communication with the injector body interior. The inclusion of a carrier fluid manifold helps to separate incoming carrier fluid from the binding agent and insulant material, and so prevent clogging of the carrier fluid inlet.
Optionally the carrier fluid manifold restricts the flow of carrier fluid into the injector body interior. Such a restriction provides a ready means of generating the desired low pressure region in a position downstream of the insulant material and binding agent inlets.
In a preferred embodiment of the invention the carrier fluid manifold includes a plurality of fluid conduits fluidly connecting the carrier fluid manifold with the injector body interior. The provision of a plurality of fluid conduits provides a desired restriction in the flow of carrier fluid and further helps to separate incoming carrier fluid from the binding agent and insulant material.
Each fluid conduit may extend in a downstream direction.
Arranging the fluid conduits to extend in a downstream direction helps to urge the mixture of carrier fluid, insulant material and binding agent out of the injector, and further resists the flow of insulant material and/or binding agent into the carrier fluid inlet.
Conveniently the carrier fluid inlet includes an annular carrier fluid manifold. The inclusion of an annular carrier fluid manifold helps to generate a uniform low pressure region in the injector body interior, and so promote uniform mixing of insulant material and binding agent.
Preferably the carrier fluid inlet includes a manifold insert to define the carrier fluid manifold, the manifold insert being selectively separable from the injector body.
The provision of a manifold insert that is selectively separable from the injector body allows ready removal of the insert from the injector body to allow cleaning and/or routine maintenance.
In another preferred embodiment of the invention the manifold insert sealingly engages with the injector body to define the carrier fluid manifold. Such an arrangement simplifies both the injector body and the manifold insert and allows ready cleaning, as desired, of both items.
Optionally the binding agent inlet includes a spray nozzle to distribute the binding agent within the injector body interior. The inclusion of a spray nozzle helps to uniformly distribute the binding agent within the injector body interior, and thereby assist in uniform mixing of the insulant material and binding agent.
The spray nozzle may be selectively separable from the injector body. The ability to separate the spray nozzle from the injector body allows an operative to easily clean the spray nozzle and injector body.
There now follows a brief description of preferred embodiments of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which:

Figure 1 shows an elevational view of a conventional injector;
Figure 2 shows a partially exploded view of an injector according to a first embodiment of the invention; and
Figure 3 shows a cross-sectional view of the injector shown in Figure 2.

An injector according to a first embodiment of the invention is designated generally by the reference numeral 50.
The injector 50 includes a hollow injector body 52 which has an insulant material inlet 54 and a binding agent inlet 56. The injector body 52 also includes a carrier fluid inlet 58 that is located downstream of the insulant material and binding agent inlets 54, 56.
The insulant material 60 may be an expanded polystyrene material, and in particular an expanded polystyrene material in bead form.
The binding agent 62 may be a vinyl acetate/vinyl ethylene copolymer or a vinyl acetate/veova acrylic ester copolymer, each diluted with water to approximately 34% solids.
The carrier fluid (not shown) may be air, and in particular compressed air. In other embodiments of the invention (not shown) the carrier fluid may be different.
The carrier fluid inlet 58 includes a carrier fluid manifold 64 that is arranged in fluid communication with the injector body interior 66. The manifold 64 restricts the flow of carrier fluid into the injector body interior 66.
In the embodiment shown the carrier fluid manifold 64 restricts the flow of carrier fluid by including a plurality of conduits 68 that fluidly connect the manifold 64 with the injector body interior 66.
In particular the manifold 64 includes a plurality of substantially cylindrical conduits 68 that are equally spaced in a radial manner from one another. Other embodiments of the invention (not shown) may include conduits having a different cross-sectional shape and/or a different spatial relationship relative to one another. Indeed, other embodiments of the invention (not shown) may include one or more restrictions in the carrier fluid manifold 64 that differ to the aforementioned conduits 68.
Each conduit 68 extends in a downstream direction D.
As shown in Figures 2 and 3, the carrier fluid inlet 58 includes an annular carrier fluid manifold 64, i.e. a manifold that adopts the shape of an annulus.
The carrier fluid inlet 58 also includes a manifold insert 70 that defines the carrier fluid manifold 64, and which is selectively separable from the injector body 52. In particular, in the embodiment shown, the manifold insert 70 is slidably received within the injector body interior 66.
The manifold insert 70 includes a pair of spaced apart first and second sealing members 72, 74. Each sealing member 72, 74 sealingly engages with the injector body 52 to define the carrier fluid manifold 64 lying between the injector body 52 and the manifold insert 70. In the embodiment shown each sealing member 72, 74 is an O-ring, although other sealing members are also possible.
The binding agent inlet 62 includes a spray nozzle 76 that is selectively separable from the injector body 52. A third sealing member 86 provides a fluid-tight seal between the spray nozzle 76 and the binding agent inlet 56. Various spray nozzles 76 having different aperture sizes may be interchanged so as to adjust the volume of binding agent 62 introduced into the injector body interior 66, and hence ensure the correct ratio of binding agent 62 / insulant material 60 is injected into a cavity.
The injector 50 may also include an on/off valve 78 adjacent to each of the binding agent and carrier fluid inlets 56, 58 to allow an operative to selectively close each of these inlets, as may be desired.
In addition, the injector 50 may include a carrier fluid manifold pressure indicator 80 to allow an operative to monitor the pressure in the carrier fluid manifold 64, as required.
In use, the carrier fluid manifold restricts the flow of carrier fluid into the injector body interior 66 so as to generate a low pressure region 82 within the injector body interior 66.
The low pressure region 82 draws insulant material 60 and binding agent 62 into the injector body interior 66 and promotes mixing thereof before urging the mixed insulant material 60 and binding agent 62 out of the injector, e.g. through a discharge pipe 84.
Optionally the binding agent 62 is supplied to the injector 50 under pressure, e.g. at 0.5 MPa (5 BAR), so as to further promote drawing of the binding agent 62 into the injector body interior 66. Pressurising the binding agent 62 may be achieved through the provision of a pressure reservoir (not shown) in a delivery vehicle which is constantly topped up with, e.g. regulated air.

Claims

An injector, for injecting a particulate insulant material and a binding agent into a cavity, the injector comprising a hollow injector body having insulant material and binding agent inlets and a carrier fluid inlet located downstream of the insulant material and binding agent inlets, the carrier fluid inlet in use generating a low pressure region in an interior of the injector body to draw insulant material and binding agent into the injector body.
An injector according to Claim 1 wherein the carrier fluid inlet includes a carrier fluid manifold arranged in fluid communication with the injector body interior.
An injector according to Claim 2 wherein the carrier fluid manifold restricts the flow of carrier fluid into the injector body interior.
An injector according to Claim 2 or Claim 3 wherein the carrier fluid manifold includes a plurality of fluid conduits fluidly connecting the carrier fluid manifold with the injector body interior.
An injector according to Claim 4 wherein each fluid conduit extends in a downstream direction.
An injector according to any of Claims 2 to 5 wherein the carrier fluid inlet includes an annular carrier fluid manifold.
An injector according to any of Claims 2 to 6 wherein the carrier fluid inlet includes a manifold insert to define the carrier fluid manifold, the manifold insert being selectively separable from the injector body.
An injector according to Claim 7 wherein the manifold insert sealingly engages with the injector body to define the carrier fluid manifold.
An injector according to any preceding claim wherein the binding agent inlet includes a spray nozzle to distribute the binding agent within the injector body interior.
An injector according to Claim 9 wherein the spray nozzle is selectively separable from the injector body.
An injector generally as herein described with reference to and/or as illustrated in Figures 2 and 3 of the accompanying drawings.