GB2168307A

GB2168307A - Pneumatic transporting apparatus

Info

Publication number: GB2168307A
Application number: GB08530127A
Authority: GB
Inventors: Gerrit Naaktgeboren
Original assignee: NAAKTGEBOREN MASCHF ROTTERDAM
Current assignee: NAAKTGEBOREN MASCHF ROTTERDAM
Priority date: 1984-12-07
Filing date: 1985-12-06
Publication date: 1986-06-18
Also published as: GB8530128D0; DE8532231U1; GB2168307B; NL8403738A; GB2168759A; NL180992C; GB8530127D0; DE8532232U1; GB2168759B; NL180992B

Abstract

For discharging a tank lorry (1) the material to be discharged is fluidized in a discharge bin (33), extra turbulence being caused in the discharging material by the projecting nature of edges 40, 41 of funnel 70 and fluidising funnel 37. By this means the disintegrating material, regardless of what kind is easily transportable. <IMAGE>

Description

SPECIFICATION Pneumatic transporting apparatus The invention concerns a pneumatic transporting apparatus according to the commencement of Claim 1.

A pneumatic transporting apparatus of this kind is widely known, for example from DE 1272227.

For these principally as cement transport vehicles embodied pneumatic transporting apparatus, the funnel-shaped fluidization air intake means always consist of a porous plate or a porous cloth, for which a danger exists that this porous means will be come clogged, particularly because a large weight of material rests on it, and even more particularly, if the material is greasy. This known pneumatic transporting apparatus is therefore not well suited to the handling of certain materials.

The invention provides a pneumatic transporting apparatus which is suitable for the handling of more kinds of material than the known pneumatic transporting apparatus of the kind concerned here.

For this purpose, the funnel part is provided with a, in relation to the wall of the fluidization box, downward-slanting, inward-projecting edge. The downward-slanting, inward projecting edge leaves free a central aperture, through which many different kinds of material can fall, without arching. The projecting edge provides an air turbulence, with the consequence that the stream of material falling through the opening breaks up, and thus becomes well fluidized.

If the characteristic of Claim 2 is applied, the danger of clogging is avoided with yet more certainty.

It should be noted that a tank lorry is known from NL-A-8100135, with fluidization means also having two conical plates, and with the fluidization air being directed inwards and downwards via a fissure formed between the two plates. Here, however, there is absent a discharge funnel edge reaching substantially further inwards than the fluidization box. the fluidization air thus reaches, in this known apparatus, material which is still compact.

An extra mixing of material and air is obtained if the characteristic of Claim 3 is applied. Thus, an especially well transportable mixture is obtained.

Perfect discharging takes place with yet more certainty for many kinds of material if the characteristic of Claim 4 is applied. Thus, as it were, a quantity is continuously sucked away from the centre of a cloud of mixed material and air.

By combination of the measures from Claims 1 to 6 inclusive, the pneumatic transporting apparatus becomes well suited to the discharge of practically any bulk material, for example for gravel, but also for milk powder for calves, and also for wet products such as mud. In particular, this pneumatic transport apparatus can be embodied with great advantage as a tank lorry.

The above-mentioned and other characteristics of the invention, and its advantages, will be elaborated in the following description with reference to the drawings.

The drawings represent, schematically, the following: Figures 1 and 2 represent a partially cut-away side and top view, respectively, of a pneumatic transporting apparatus according to the invention, embodied as a tank lorry.

Figures 3 and 4 show a diagram of the tank lorry of figure 1 during, respectively, sucking up and expulsion of material.

Figure 5 shows a partially cut-away perspective view of detail V of figure 3.

Figures 6 and 7 show, on an enlarged scale, cross-sections through line VI-VI in figure 1, and line VII-VII in figure 5, respectively.

The tank lorry 1 according to the invention comprises a chassis 2 which carries a cylindrical tank 3.

Tank 3 is fastened to chassis 2 at its rear end 7 tiltably around a horizontal axis 6, and at its front end 8 raisably by a hydraulic jack 9, so that the tank 3 can be tilted as far as the raised position indicated by dashed lines in figure 1. The front end 8 of the tank encloses a filter space 10 of a filter apparatus 4, which is separated by a partition 11 from a space 12 for storage of material. The rear end 7 of tank 4 is closed off by means of a cover 14, which is fastened to tank 3 pivotably around a horizontal axis 13, is sealed by means of a gasket (not shown) and is locked in the closed position by means of latches (not shown). Material can be discharged where necessary by letting it run from tank 3, with tank 3 in the raised position, and cover 14 open.

Tank 3 has on its top two airtight removable covers 15. When tank 3 is filled from a silo, the material can be discharged into tank 3 with the covers 15 removed.

For sucking up material, a hose 16 is connected via a shut-off valve 17 to tank 3, and furthermore, to create a vacuum in tank 3, there is a suction aggregate 5 present, comprising a blower 18 with figure-of-eight shaped impellers 19. This is a so-called Roots compressor, which, according to the power of the motor 54, can displace 1000-7000 m3 per hour. The intake side of the blower 18 is connected to the storage space 12 via a conduit 21, a silencer 22 and the filter apparatus 4, while its outlet side 24 is connected to the atmosphere via a conduit 25 with a silencer 26, and via a shut-off valve 23.

Conduit 25 branches by means of a distribution control valve 45 into a fluidization air conduit 29 provided with a control valve 27, and a blow air conduit 31. Before control valve 27, the fluidization air conduit is connected to a secondary air conduit 28, provided with a control valve 30. The fluidization air conduit 29 is closed off when gravel is being discharged, but is opened for use with fine material. At the bottom of cover 14 there is a discharge funnel 32 present, a bottom funnel part 70 being connected, as shown in figure 6, to a discharge bin 33, such that an edge 40 extends further inwards than the wall 35 of fluidization bin 34, so that turbulence in the material arises at edge 40.

The opening 96 of the funnel 32 has a diameter g of 70cm., that is to say large enough to prevent obstructive arching in the material. In the fluidization bin 34, there is welded a funnel 36, under which a funnel 37 is located, leaving free a fissure 38. The fluidization conduit 29 is connected to the fluidization bin 34 beneath funnel 37 which is provided with apertures 39, so that fluidization air from conduit 29 can reach the downwards flowing material via appartures 39 and fissure 38.

The funnel 37 projects at an edge 41 further inwards than wall 43 of the mixing bin 42 connected thereto. The conduit 28 for secondary air projects with its discharge orifice 81 from wall 43 into the mixing bin 42 for some way inwards up to a certain distance from, and in line with, the entrance 71 of a discharge tube 44, so that the fluidized material which, owing to the edge 41, has extra turbulence, mixed with secondary air 57, is directed into discharge tube 44 in the direction of arrow 46. The entrance 71 projects, relative to wall 43 of mixing bin 42, some way inwards. The discharge tube 44 is connected via a shut-off valve (48) and mixer 47 to a delivery hose 49.In the mixer 47, blow air from the thereto connected blow air conduit 31 is added to the material/air stream, insofar as that is necessary in order to transport the material for a large distance andlor to a considerable height. The air delivered by suction aggregate 18 may be supplied, distributed according to requirements by means of a distribution control valve 45 between fluidization air and secondary air via conduits 29 and 28 respectively to discharge bin 33. With the discharge bin 33 of figure 6, even gravel with a grain diameter of 10-60mm. can be blown onto roofs of a height, for example, of 40 metres. Similarly garden earth and other material can be blown to distant, high and inaccessible places.

It should be remarked that in each of the conduits 21 and 25, there is a rotatable coupling 50 built in coaxially with the axis 6, and that a detachable tube coupling 51 is built into the conduit 25 in the closure plane of cover 14.

The blower 18 is driven by a motor 54 via a beltdrive 52, a propellor shaft 53 and a clutch 55, the motor also being used for propulsion of the tank lorry 1. When material is being blown out of tank 3, the blower 18 is connected to the atmosphere via a conduit 21 and a shut-off valve 56 For sucking material into tank 3, a strong vacuum is created in the tank 3, preferably up to 98% if necessary, that is, up to 200 mm. water-column equivalent.

The lower space 72 of filter space 10 is connected via a conduit 58 with a shut-off valve (59) to an evacuation chamber 60, which, via an entrance 61 provided with a check valve 62, connects at a high level to the storage space 12. The bottom of the evacuation chamber 60 consists of baffle plates 63. The evacuation chamber 60 is arranged in the top of storage space 12, in order that as little material as possible should be sucked into filter space 10. In the filter space 10 there is arranged a multiplicity of adjacent flat suction grids 64, which have external filter bags 65. The cages 64 are largely closed at their tops by injection tubes 66, each of which is connected via a separate valve to an air pressure vessel 68, which forms a pulsed air source.The suction conduit 21 is connected to the upper space 69 of the filter space 10, and thus stands in connection, via fissures 70 on each side of injection tubes 66, with the interiors cages 64, so that air is sucked out of the lower space 72 of filter space 10 through the filter bags 65, so that any material present in the air is held back. In order to maintain the suction efficiency of blower 18, the filter bags 65 are periodically beaten out by means of a control organ 73, through valves 67 each being briefly opened in turn for the injection of a compressed air pulse. The filter bags 65 are then suddenly inflated, and there results a beating effect which causes the filter bags 65 to be cleaned.

Owing to the vacuum in the cylindrical tank 3 being very strong, for example stronger than 1m.

water-column equivalent and preferably of the order of magnitude of 200mm. water-column equivalent, the air which passes through filter bags 65 is very thin, so that this air is easy to filter. Consequently the filter apparatus 4 can be given small dimensions, so that a large cargo space can be built onto tank lorry 1. The compressed air vessel 68, which can also function as a brake-systme air tank, is filled with compressed air from a compressor 74, driven by a motor 54.

The impeller space 75 of the blower 18 is provided in its circumferential wall on each side of blow air outlet 76 with a slit-shaped, extending principally in the axial direction 89 of the rotor shafts 90, cooling air inlet 77, which is connected to the atmosphere via a branch 88 of a manifold 80, a common cooling air supply 87, a shut-off valve 78 and a silencer 79.

As figure 7 shows, each cooling air inlet 77 is positioned at an angular separation j of approximately 180" from the air intake 20, whereby it is brought about that the compression space 94 enclosed by the circumferential wall 92 and the two principally cylindrical head of a given impeller 19 remains closed off from the cooling air inlet 77 by the lower head 93, as long as compression space 94 stands in connection with the air intake. In this situation shown in figure 7, the compression space 94 is separated from air inlet 20 as well as from cooling air inlet 77 by a narrow gap 97, between each head 93 on the one hand, and the circumferential wall 92 on the other. The heads 93 of the impellers 19 are flattened at the position of gap 97 to a radius r, which is greater than the main radius q of the principally cylindrical impeller heads 93. In the situation of figure 3, owing to the vacuum predominating in the impulsion space 75, atmospheric air is drawn in, and thus cools the blower 18 in a simple and effective way, such that this can be made with precision. Excessive expansion of the impellers 19, which would lead to their seizing, is avoided by cooling them. The blower 18 can consequently work efficiently at various and high rotation speeds.

Figure 5 shows a manifold 80 for connection of the silencer 79 to the two inlets 77 on either side of the blow air outlet 76. Through the strong vacuum, many different kinds of material, dry as well as wet substances and even gravel, sludge or stones can be sucked up. Discharging of the materials sucked up and transported by tank lorry 1 can take place, as well as by tipping, also, with cover 14 opened, by blowing out, for which tank 3 is usually also tilted around axis 6. The top of the collecting space 12 of tank 3 does not have to be provided an air supply. During discharging, the air and material stream is as indicated by arrows in figure 4. The material which is retained by filter bags 65 during sucking up arrives in storage space 84 of the filter apparatus 4, and when tank 3 is tilted it falls through a check valve 85 into the storage space 12.

The pneumatic transporting apparatus according to the invention is also applicable, for example, as a street sweeping machine, this being embodied as a dust aspirator with a roller brush.

Furthermore, the pneumatic transporting apparatus can be build, besides into a tank lorry, into a transshipment plant, material being sucked up, for example, from a ship's hold and transported into a fixed or a mobile tank, in the case of a fixed tank the material subsequently being discharged by transportation of the material into another ship's hold, or into a vehicle.

It should be noted that for a tank lorry, a hose of 10 to 15 cm. diameter is usable, considerable lengths of such a hose being easily conveyed with a tank lorry 1. This narrow hose diameter is a consequence of the powerful vacuum or the high degree of compression which is realized with blower 18, whereby clumsy and heavy hoses with large diameters are avoided. After all, an adequate transportation velocity can be realized in the narrow hose.

Claims

1. Pneumatic transporting apparatus comprising at least one tank, at least one material discharge conduit connected to a discharge funnel, at least one fluidization air conduit connected to the conduit connected to the discharge funnel, at least one secondary air conduit connected to the discharge funnel and fed by a blow air aggregate and a conical funnel-part of fluidization bin which is provided with funnel shaped fluidization air inlet means of which a central outlet debouches into a discharge bin in which a supply conduit of secondary air debouches through an influx nozzle opposite an entrance of the material discharge conduit; wherein the funnel-part is provided with a downward-slanting, inward-projecting edge relative to the fluidization bin.

2. Pneumatic transporting apparatus according to claim 1, wherein the fluidization means comprise funnel forming plates and air fissure for the downwards and inwards direction of fluidization air.

3. Pneumatic transporting apparatus according to claim 1 or 2, wherein a funnel forming plate of the fluidization means projects inwards with its inner edge past the wall of a further discharge bin thereunder.

4. Pneumatic transporting apparatus according to any one of claims 1 to 3, wherein the influx nozzle of the secondary air conduit project some distance inwards from the wall of the discharge bin.

5. Pneumatic transporting apparatus according to any one of the preceding claims, wherein the tank has air supply provisions only at its bottom.

6. Pneumatic transporting apparatus according to one of the preceding claims, wherein the material discharge conduit is connected outside the discharge bin via a compressed air conduit to an air aggregate.

7. Pneumatic transporting apparatus according to one of the preceding claims, characterised in that this apparatus is embodied as a tank lorry which has a vehicle chassis which carries the tank as well as an air aggregate.