GB2124194A

GB2124194A - Insulation dispensing apparatus

Info

Publication number: GB2124194A
Application number: GB08207423A
Authority: GB
Inventors: John Keith Herbert Mason; Earl Frederick Sommers
Original assignee: ECOMAX
Current assignee: ECOMAX
Priority date: 1981-03-13
Filing date: 1982-03-15
Publication date: 1984-02-15
Also published as: GB2124194B

Abstract

A hopper for storing insulation material, e.g. mineral fibres, to be fed to a pump, is discharged via a rotary means in a trough (12) at the bottom of the hopper. The rotary means has a shaft (16) carrying blading (19) spaced from the shaft and following a helical locus. Exit (30) from the trough is associated with modified blading, shown as discrete paddles (20), to slow the material. Also, flexible flails at the exit serve to sweep its edges clean. <IMAGE>

Description

SPECIFICATION Insulation dispensing apparatus The invention relates to apparatus for dispensing insulation as finds use in pumping, usually from a vehicle, into the roof space, and wall cavities, of buildings.

It will be appreciated that such apparatus requires material to be in divided form so as to be capable of forced travel, usually in an air stream, through a delivery tube or pipe, usually flexible, to the desired place for the insulation. Granulated or shredded mineral fibre insulation materials, are suitable for the purpose. In general, machines suitable for the purpose require a storage hopper and feeding means therefrom to a pressurising delivery pump. The feeding means is best organised to cooperate with an outfeed of the storage hopper to have a shredding, granulating or other suitable dividing action on the insulation material at least to counteract any densification compacting or agglomeration thereof under its own weight in the hopper or by action of a conventional auger outfeed therefrom.

Any compaction or agglomeration or reduction of actual separation of the divided components of the insulation material has two deleterious effects in reducing insulation value and increasing the quantity of material required for a desired nominal insulation thickness or volume.

This invention is directed particularly at minimising compaction problems at the outfeed from the storage hopper.

According to the present invention there is provided an insulation dispensing machine comprising a storage hopper for divided insulation material, pump means for forced delivery of divided insulation material via a pipe or tube, and feeding means between an outlet from the bottom of the hopper and an inlet to the pump means, wherein the hopper has, for feeding material to its outlet, a trough-like bottom about at least a lower part of a rotary bladed feed shaft of which the blading secured thereto has at least its major material feeding extent spaced from the shaft itself to leave about the shaft a relatively free volume for the insulation material.

A particularly preferred blading follows a helical ribbon path coaxial with the shaft and secured thereto at intervals, say by radially extending rods or spokes. A single continuous helical ribbon blade closely fitting to the bottom of the trough has been found to be most satisfactory in reducing any tendencies to compaction of insulation material in the trough as occurs where a solidly bladed auger is used. We shall refer to such a bladed shaft as a "ribbon auger", which term is to include both multistart and discontinuous ribbon blades so long as blade components thereof follow a generally helical path usually but not necessarily of substantially constant pitch.

Such a ribbon auger will, of course, promote movement of insulation material along the trough to an outlet therefrom, usually at one end, though an outlet medially of the trough could, if desired, be fed from both sides by opposite handings of blading to different sides thereof. At the position of that outlet, gravity assists translation of material movement from the direction of the shaft to downward through the outlet. Further assistance can be obtained from slowing translation along the shaft by securing paddles to the shaft, usually on radial rods or spokes.

Discrete paddles on a double-helix locus are satisfactory for this purpose.

Another most useful feature, aimed at avoiding build-up of insulation material about the outlet, is the provision of flexible flails secured to the shaft at the outlet position, again usually on radial rods or spokes, with terminations at a greater radial spacing from the auger shaft than the trough bottom, so as to "sweep" edges of the outlet.

We have found that it is also generally advantageous to be able to adjust the size of the hopper outlet and our preferred machine permits that simply by adjustment of a sliding plate or plates to vary the width of an outlet cut in the bottom of the trough. The flails mentioned above are then of even more assistance in avoiding build-up of material.

The discrete blading, preferably with the flexible flails, promote change from axial to downward movement at the outlet, though they may also produce some upward circulatory movement of the insulation material within the hopper.

We also prefer that the hopper itself shall be a moulding of material, such as fibre glass, that will not be subject to corrosion and will, in use, become progressively "slippier" so that risks of localised build-up of insulation material anywhere in the hopper will be reduced, though mild steel could be used if desired.

One specific embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 shows a combined hopper and shredder housing; Figure 2 shows a hopper outfeeder, shredder and air valve distributor; Figure 3 shows the shredder and air valve; Figures 4, 5 and 6 show central and end parts of an air valve housing; Figure 7 shows an automatic nozzle; and Figure 8 shows a preferred hopper top.

Fig. 1 shows a moulded plastics container 10, though it could be of mild steel, having a hopper portion 11 with downwardly convergent sloping sides to a trough-like bottom 1 2 and a shredder housing portion 13 below one end of the hopper bottom and communicating therethrough. The container 10 is advantageously a low function material at least internally and may be of a conventional glass-fibre-inresin type even, if desired, suitably lined, or mild steel lined and/or coated, say with Teflon (Registered Trade Mark), so that, in use, there will inherently be a high degree of slip that will if anything increase in slipperiness with use.Such a container will resist roughening and corrosion at its inner surfaces, and its convergent side walls preferably have steep slopes, preferably greater than 45, even parabolic, as particles of insulation material do not readily slide over each other.

Fig. 2 shows a ribbon auger 1 5 to fit in the trough-like bottom 1 2 of the aforementioned hopper 11. The ribbon auger 1 5 comprises a shaft 1 6 which has spoke-like radial rods 17, 1 8 extending therefrom. The rods 1 7 are spaced along and about the shaft from one end to an outlet 30 to the shredder and support a helical ribbon 1 9 spaced from the shaft and constituting means for translating divided insulation material towards the hopper outlet 30 with a minimum of compaction of the insulation particles thereof. The rods 18 above the hopper outlet support paddles 20 that are actually disposed at intervals along the loci of opposite handed helices.The paddles 20 then form a particularly effective mechanism for gently stopping the insulation particles in their movement along the shaft 1 6 by the ribbon 1 9 and encouraging their exit evenly through the hopper outlet 30.

Attached to the paddles 20 are flexible flails 20A extending well beyond the paddles themselves to sweep edges of the hopper exit and avoid build-up there of insulation material.

The shaft 1 6 will be suitable journaled in holes, such as 21, in the hopper 11 to be rotated at 22 by a suitable drive, normally taken from the engine of a vehicle carrying the insulation pumping apparatus being described.

Turning now to Fig. 3, the shredder housing 13 is shown with upwardly divergent sides 23, 24 and is traversed by two counterrotating shredder shafts 25, 26 each equipped with blades 27, 28 that interleave marginally and further cooperate with stationary blades 29 in enhancing particulation of the insulation material from the hopper 11 (Fig. 1). An inlet pipe 34 is shown at a low position in the shredder for injection of lowpressure air the further to aid separation of the insulation particles and smooth flow out of the shredder. Holes in the container 10 are shown at 31, 32 (Fig. 1) for the shredder shafts 25, 26 to be driven at 30, 31 and at 33, for air inlet pipe 34, if desired via a mesh screen or permeable membrane.

Fig. 3 also shows a slide 36 for varying out-flow from the shredder to an air valve 37 comprised of a shaft 38 carrying radial lengthwise vanes 39 establishing chambers between them that will be substantially sealed one from the other by coaction of the vanes 39 and the interior of casing 40 below the shredder outlet. Those chambers will load consecutively as shaft 38 rotates.

The counter-rotatable shredder shafts 25, 26 are actually at different heights and the higher one 26, relatively rearward in Fig. 3, has flat chopper blades of greater extent than the narrow blades of the other lower shaft 25.

It is the upper chopper bladed shaft that coacts with stationary blades 29 and the air inlet 34 terminates somewhat over half way across the shredder housing, i.e. under the upper shredder blades.

The housing 40 of air valve 37 is shown in greater detail in Figs. 4, 5 and 6 with a central cylindrical portion and end plates 41, 42. A bottom groove or indent 43 extends from an air inlet 44 to an angularly offset outlet 45, i.e. at an angle to vanes 39, so as to scavenge each air valve chamber progressively and to afford smooth transition between consecutive such chambers.

The shredder shafts will be driven at 46, 47 by suitable gearing if necessary variable and equipped with a clutch, and an air pump will also be provided from which shredder air supply can be bled off and the remainder used to supply air valve inlet 44. A flexible pipe from air valve outlet 45 will take the insulation entrained in air to its application point. At least for filling wall cavities, if not also for assuring particular insulation depths in roof spaces, it is desirable to have an automatic cut-out on the delivery end of the pipe so that delivery stops when the end is covered. That is done readily as shown in Fig.

7, where a pipe end fitting or nozzle 48 has a chamber 47 prior to and of greater crosssection than its actual outlet 49. Within the chamber 47 a closure plate 50 is hinged at 51 and carries a spacer 52 so that, in the its open position shown dashed, the spacer will abut a wall of the nozzle. Any obturation of the exit 49 will cause a back pressure to build up allowing or forcing the plate 50 to close.

Refinements concerning air flow control, which facilitate optimum adjustment and operation for various applications, include providing an air pump outlet with a spill branch, say at an elbow fitting to which a variable valve or a selection from different size spill orifice parts is attached. Clearly, valving from such a spill branch may include supply to the shredder for aeration purposes, say using a particular size of possible orifice parts 56 teed into the spill branch between the pump outlet and a variable valve.

Also, it is proposed to detect pressure of the air/insulation mixture, or the air alone prior to air valve 37, say by a pressure sensitive device to indicate that a desired volume and density of insulation fill, say in a wall cavity, has been achieved. Such a pressure sensor may operate an indicator, or a switch to automatically shut down the mechanical and pneumatic drives of the pumping apparatus, say by disabling electric clutches, if desired in a particular sequence.

One other worthwhile feature of our preferred pumping apparatus is indicated in Fig.

8. It will be appreciated that the hopper needs to be closed except when the apparatus is in use and preferably protected from intrusions that could damage its outfeed arrangement when being loaded. Thus we provide a combined top cover and side extension arrangement by way of hinged leaves 60, 61, 62, 63 that can be locked open as at 64 on three sides with an extension (63) to the fourth side adjacent to protective mesh 65 over part of the hopper top.

We have found that only for hoppers of much greater heights is it desirable to have any further circulator system above the described ribbon auger, the latter and provision of slippery surfaces for the hopper interior generally being adequate to the purpose.

Slider plate provision at the hopper exit is, of course, desirable and sensed pressures will normally be in the range of from 1 to 4 pounds per square inch for deliveries of about 200 cubic feet per minute.

We find it advantageous to utilise seven equispaced vanes 39 and a trough 43 inclined so that its ends are angularly displaced by about the spacing of the vanes 39. Fig. 2 shows such spacing, but with the sectional showing at the bottom indicating that the section concerned is close to the exit end of the chamber 37, though a more symmetrical disposition of the trough 43 could be used (relative to the bottom of the chamber 37).

Such a seven-vaned, vane-sprung-traversingtrough arrangement is particularly effective in use.

Claims

1. An insulation dispensing machine comprising a storage hopper for divided insulation material, pump means for forced delivery of divided insulation material via a pipe or tube, and feeding means between an outlet from the bottom of the hopper and an inlet to the pump means, wherein the hopper has, for feeding material to its outlet, a trough-like bottom about at least a lower part of a rotary bladed feed shaft of which the blading secured thereto has at least its major material feeding extent spaced from the shaft itself to leave about the shaft a relatively free volume for the insulation material.

2. An insulation dispensing machine according to claim 1, wherein said blading follows a helical ribbon path coaxial with the shaft and secured thereto at intervals by radial members.

3. An insulation dispensing machine according to claim 2, wherein the blading is a continuous helical ribbon closely fitting to the bottom of the trough.

4. An insulation dispensing machine according to any preceding claim, wherein the trough has a material outlet near one end thereof.

5. An insulation dispensing machine according to any preceding claim, wherein the shaft has material slowing means at outlet from the shaft.

6. An insulation dispensing machine according to claim 5 with claim 3, wherein the material slowing means comprises discrete paddles spaced from the shaft beyond the extent of the continuous helical blade.

7. An insulation dispensing machine according to claim 6, wherein the paddles lie on a double helix locus.

8. An insulation dispensing machine according to any preceding claim, wherein the shaft has flexible flails secured thereto at outlet from the trough.

9. An insulation dispensing means according to any preceding claim, comprising orifice varying means for outlet from the trough.

10. An insulation dispensing means according to claim 9, wherein the outlet varying means comprises sliding plate means.

11. An insulation dispensing means according to any preceding claim, wherein the hopper itself or an insert lining therefor is a moulding of material, such as glass fibre/resin, that is corrosion resistant and surface polishes in use.

1 2. An insulation dispensing means according to any preceding claim, wherein the hopper has a generally rectangular top with cooperating cover parts hinged to its sides, three of the cover parts being interlockable as upward side extensions, and the fourth cover part being operative relative to protective mesh over part of the hopper top from that side.

1 3. An insulation dispensing machine according to any preceding claim, wherein the feeding means includes parallel counter-rotating bladed shafts serving to lift material between them and lower it past their outer peripheries.

14. An insulation dispensing machine according to claim 13, wherein the blade of the counter-rotating shaft intercalate marginally.

1 5. An insulation dispensing machine according to claim 1 3 or claim 14, wherein one of the counter-rotating shaft is higher than and to one side of the other.

1 6. An insulation dispensing machine according to claim 15, wherein the higher of the counter-rotating shaft has broad blades and the other has narrow finger like blades.

1 7. An insulation dispensing machine according to claim 16, wherein both of broad and narrow blades constitute diametrical pairs, the pairs of broad blades being successively axially spaced at 90 angular displace ments and the pairs of narrow blades being successively axially spaced at 45 angular displacement.

18. An insulation dispensing machine according to any one of claims 1 3 to 17, wherein blades of either or both of the counter-rotating shafts cooperated with fixed blades on the interior of a casing.

19. An insulation dispensing machine according to any one of claims 1 3 to 18, wherein a or the casing for the counterrotating shafts has downwardly convergent sides parallel with the shaft axes.

20. An insulation dispensing machine according to any one of claims 1 3 to 19, comprising means for injecting low pressure gas below the counter-rotating shafts.

21. An insulation dispensing machine according to claim 20 with claim 14, wherein injection is below intercalation of the blades of the counter rotating shaft.

22. An insulation dispensing machine according to any one of claims 1 3 to 21, comprising variable orifice exit means below the counter-rotating shafts.

23. An insulation dispensing machine according to claim 22 with claim 15, wherein the exit is below the higher one of the counter-rotating shafts.

24. An insulation dispensing machine according to any preceding claim, comprising a pump feed via a cylindrical chamber having material entry through an upper side and rotary vanes effectively dividing the chamber into rotating sub chambers in turn passing over a bottom trough-like pumped outlet formation inclined to the axis of the cylindrical chamber.

25. An insulation dispensing machine according to claim 24, wherein the trough-like formation has its ends angularly displaced by about the peripheral pitch of the vanes.

26. An insulation dispensing machine according to claim 25, comprising seven equiangularly spaced vanes.

27. An insulation dispensing machine arranged and adapted to operate substantially as herein described with reference to and as shown in the accompanying drawings.