EP1555223A1

EP1555223A1 - Valve, preferably for a waste suction system, and method for using the valve

Info

Publication number: EP1555223A1
Application number: EP05000751A
Authority: EP
Inventors: Erik Lund Sorensen
Original assignee: RENOVAC AS
Current assignee: RENOVAC AS
Priority date: 2004-01-16
Filing date: 2005-01-14
Publication date: 2005-07-20
Also published as: DK200400052A; DK175979B1

Abstract

The present invention concerns a valve (1) for regulating a mass flow, preferably a mass of waste in a waste suction system (30), including a valve chamber (2), a displaceable valve plate (3) and an actuation unit (4), where the valve chamber (2) at one end is adapted to be disposed between two pipe ends (5, 6), and where the actuation unit (4) is disposed at a second end of the valve chamber (2) and adapted to displace the valve plate (3) in the valve chamber (2) from a closed first position to an open second position, where the valve chamber (2) is designed with a number of air inlets (12) designed to lead secondary transport air in through the valve (1).

The present invention furthermore concerns a waste suction system (30), including a pipe system (31, 32), a number of waste shafts and a number of valves (1), where the valve (1) is disposed in the pipe system (31, 32) so that the secondary transport air (A) through the air inlet (12) is in downstream flow of a primary transport air (D) through the pipe system (31, 32).

The present invention furthermore concerns a method for using a valve (1) in a waste suction system (30).

Description

Scope of the Invention

The present invention concerns a valve for regulating a mass flow, preferably a mass of waste in a waste suction system, including a valve chamber, a displaceable valve plate and an actuation unit, where the valve chamber at one end is adapted to be disposed between two pipe ends, and where the actuation unit is disposed at a second end of the valve chamber and adapted to displace the valve plate in the valve chamber from a closed first position to an open second position.
The present invention furthermore concerns a waste suction system, including a pipe system, a number of waste shafts and a number of valves.
The present invention furthermore concerns a method for using a valve in a waste suction system.

Background of the Invention

In a modem waste collection system, the collection of waste from e.g. apartment blocks occurs by means of a fully automatic and closed system that is emptied after each waste collection by means of vacuum into either a common container or a similar common vessel.
The waste is thrown in e.g. waste shafts or throw-in openings under which there is provided a waste magazine that may store the waste until the waste magazine is emptied.
In order to prevent smell nuisances from the waste in the waste magazine coming to the users of the waste collection system, the waste magazine is provided with valves that both shut off the waste approximately airtight inside the waste magazine and blocks outwards to the pipe system of the waste collection system.
When the waste is emptied from the waste shaft by means of vacuum, the valve in the outlet opening is to be opened, and transport air is to be supplied to the waste magazine in order that the airstream may loosen and transport the waste away.
In International Patent Application WO 00/46129 there is described a system where there is used a "refuse discharge valve" (RDV) together with a pipe system for sucking in transport air in the waste magazine so that the waste can be loosened and transported away.
A drawback of this system is that there is to be used some piping, extra pipe connections and techniques for making it function satisfactorily and thereby cause the waste to be loosened and conveyed onwards.
Another drawback of this system is that the RDV valve is not self-cleaning, which means that there is risk of waste material and liquid accumulating at the bottom of the valve chamber, which eventually will cause failure of the valve plate, reducing the efficiency of the RDV-valve.
Particularly in the interspace between pipe ends of the adjacent pipe system waste material may fall down in the valve chamber, and subsequently accumulation of material occurs, which may prevent the valve plate from closing 100% tightly when the waste magazine is to the used for collecting waste.
Besides, liquid penetrating down into the interspace between pipe ends and valve chamber may furthermore entail that the valve plate in a closed position with be in an aggressive environment slowly corroding the valve plate and the valve chamber, causing the service life of the valve plate to be considerably reduced.
These drawbacks are acknowledged to some extent in the description in the International patent application WO 00/46129, but the solution of adding transport air in a pipe connection just before the RDV-valve does not alter the fact that there is to be used some piping, extra pipe connections and techniques, and that the RDV-valve is not self-cleaning.

Object of the Invention

It is the purpose of the present invention to indicate a valve for preferably waste suction systems, where this valve is designed simple, self-cleaning and functioning automatically during operation.
This is achieved by means of a valve as specified in the preamble of claim 1, and where the valve chamber is designed with a number of air inlets arranged to lead secondary transport air in through the valve.
Another purpose of the present invention is to provide a waste suction system which is designed simple and where a valve according to the present invention is used, and where the valve is disposed in the pipe system so that the secondary transport air through the air inlet is in downstream flow of a primary transport air through the pipe system.
A further object of the present invention is to indicate a method for using the valve according to the present invention in a waste suction system.

Description of the Invention

In order to provide a simply designed valve, there is used a valve in the shape of a slide valve that includes a valve chamber, a displaceable valve plate and an actuation unit, where the valve chamber encloses the displaceable valve plate, which is displaced by means of the actuation unit.
The valve chamber is furthermore arranged for interconnection between two pipe ends so that the joining of the pipe ends occurs inside the valve chamber. In order to make room for the valve plate, the pipe ends are joined so that an interspace is left between pipe ends through which the valve plate may be displaced for shutting off the mass flow in the pipe system.
The actuation unit causing the displacing of the valve plate in the valve chamber may be a cylinder, a mechanical arrangement or similar, which may displace the valve plate rapidly and easily.
In a preferred embodiment of the present invention, the actuation unit is a pneumatically driven cylinder mounted on the valve chamber and connected to the valve plate.
Alternatives to a pneumatically driven cylinder may be other types of cylinders that e.g. are powered by electricity, hydraulics or the like, or a mechanical arrangement, e.g. a rack and pinion unit which is powered by a motor unit.
In order to close the waste magazine, the valve is adapted so that the valve plate may be displaced in the valve chamber from a first closed position to another open position, either as a variable continuous movement or in steps.
In a preferred embodiment of the present invention, the valve is arranged so that the valve plate is displaced in a continuous movement, causing the waste lying in the front of the waste magazine to be loosened at a controllable rate and subsequently to be conveyed away, without arising any chock effect with a sudden movement of a large amount of waste which may form a plug in the succeeding pipe system.
It is important to be able to control the opening period of time of the valve plate, because there are disadvantages connected with too rapid opening as well as too slow opening.
Too rapid opening of the valve plate entails a chock effect where a large amount of waste is suddenly drawn through the pipe system and thereby may form a plug in the succeeding pipe system.
Too slow opening of the valve plate entails that the primary transport air has managed to move so much waste right up to the valve so that it clogs, and thereby it is not possible for the secondary transport air to loosen and accelerate the waste onwards in the pipe system.
A preferred opening time of the valve plate is 2 - 5 seconds.
In order to avoid mechanical problems with the valve in the form of accumulation of waste material in the valve chamber and corrosion of the valve plate and valve chamber, it is important that the valve is self-cleaning.
This is achieved by the valve chamber being designed with a number of air inlets that allow suction of secondary transport air in through the valve.
This secondary transport air has a plurality of functions, for example:

When the valve plate is displaced from the closed first position, the secondary transport air will entail a strong flow about the valve plate so that it entrains waste materials that has dropped down between the pipe ends and down to the bottom of the valve chamber.
The secondary transport air will loosen the waste lying at the front of the waste magazine.
The secondary transport air will contribute to the loose waste being centred in the pipe system, accelerated and carried away as "beads on a string".

The secondary transport air is conducted through the valve from the moment on when the valve plate is lifted, and until the valve plate is back in a closed position.
As the valve can be disposed at different positions in a waste suction system where there are different requirements to the amount of secondary transport air, it is an advantage if the air inlet of the valve can be adjusted. The said air inlets are therefore designed with an adjustable closing arrangement.
This provides that it is possible either to set the amount of secondary transport air once before using the valve, or to adjust the amount of secondary transport air concurrently during the use of the valve.
Typically, it will be so that the valve is calibrated, whereby the exact amount of secondary transport air is determined, and the closing arrangement is set.
The closing arrangement may be any kind of shut-off valve where it is possible to set the shut-off valve at certain positions in order thereby to allow different amounts of secondary transport air to penetrate through the valve.
In a waste suction system with a manually operated closing arrangement, the amount of required secondary transport air is determined once and thereafter set. This method may be used for waste suction systems where adjustment of the closing arrangement seldom occurs, apart from maintenance/overhaul of the valve.
If the closing arrangement is used in a waste suction system where the amount of required secondary transport air is adjusted concurrently, the said adjustable closing arrangement is coupled to a control which may activate and control the closing arrangement according to the actual conditions.
This control may be:

coupled to a valve control controlling the valve plate so that the amount of secondary transport air is adapted to the opening period of the valve plate and the time for supply;
a separate control which e.g. is coupled to a main control, whereby the amount of secondary transport air to the valve may be controlled and may e.g. be adapted to the amount of primary transport air or the power of the suction vacuum; or
be a combination of the two above possibilities.

The control may be placed centrally in a control compartment, entailing that it is not necessary physically to access the closing arrangement in order to adjust the amount of secondary transport air.
In order to have the greatest possible useful effect of the secondary transport air through the valve, it is important that the secondary transport air is conducted through the valve, so that it is in downstream flow with the primary transport air.
This entails that the air intakes are disposed at one side of the valve chamber, which in practice is the side facing the waste magazine.
The air inlet may, however, be mounted upon or at the side of the valve chamber. If the said air inlets are disposed at a side of the valve chamber, it will be impossible to orient the valve incorrectly, as it will clearly appear from the installation instructions that the secondary transport air is to be supplied to the primary transport air in downstream flow.
Previously, valve plates of stainless steel or other resistant metal alloys have been used, possibly provided with a plastic coating, but experience shows that wear on the valve plate has caused the coating to wear off, and that the aggressive environment occurring because of the waste, which is a mixture of common household refuse, will cause corrosion anyway of a valve plate of stainless steel or other metal alloy.
The said valve plate is made of a plastic material, e.g. polycarbonate, which is hard and which can resist the aggressive environment. In order to attain sufficient strength of the valve plate, it will therefore be required to make it with greater thickness than a valve plate of metal.
This entails that the interspace between the pipe ends in the valve chamber is to be larger. This is, however, no disadvantage, since thereby there is greater probability that the secondary transport air led down around the valve plate may better entrain possibly accumulated waste material and liquids that have run down to the bottom of the valve chamber.
In an embodiment of the invention, the valve chamber is designed with inlet connections for the pipe ends so that the pipe ends are connected at the outside of the valve instead of inside the valve.
In that way it is ensured that the valve plate is closing completely tight in the closed first position, as the valve is designed internally so that the pipe ends are fitting exactly with the thickness of the valve plate.
In a modem waste collecting system, a waste suction system in e.g. an apartment block constructed so that waste is thrown into waste shafts or throw-in openings under which there is provided a waste magazine that may store the waste until the waste magazine is emptied.
In order to make the valves in the waste suction system function optimally, the valve is disposed in the pipe system so that the secondary transport air through the air inlet is in downstream flow of a primary transport air through the pipe system.
This means that the secondary transport air contributes to loosen the waste in the waste magazine and accelerate the waste, and simultaneously it provides for the valve being self-cleaning, as accumulated waste material in the valve chamber is entrained and carried away from the waste magazine.
If the valve is self-cleaning, it means lower costs for maintaining the valve, and the efficiency of the waste suction system is increased.
In an embodiment of the invention, the valve is disposed in the pipe system immediately after a waste shaft or a waste magazine, where the valve is used as a shut-off valve holding back the waste in the waste magazine.
In order to loosen, accelerate and transport the waste away from the waste magazine, primary transport air is to be applied through the pipe system together with an amount of secondary transport air through the valve.
In a second embodiment of the invention, the valve is disposed in the pipe system with spacing to a waste shaft or a waste magazine, where the valve is used as a sectional valve keeping parts of the pipe system of the waste suction system shut off.
It is used typically if the waste suction system has a certain size where it is impossible to subject the entire pipe system to vacuum at once.
In order to keep up the transport of waste away from a section of the pipe system, primary transport air is to be applied through the pipe system together with an amount of, or no, secondary transport air through the valve.
As the valve is designed so that the opening between the pipe ends corresponds the thickness of the valve plate, the valve may be disposed in the pipe system at an angular position that will entail that the valve can be placed on vertical pipes, on pipes with a slope or on horizontal pipes, without harming the functionality of the valve.
In the preferred embodiment of the invention, the valve is used as a shut-off valve in a waste suction system, and an emptying of a waste magazine is effected according to the following steps:
a) a vacuum is formed in the pipe system, provided on the suction side of the valve;
b) the valve is opened by lifting the valve plate in a continuous movement;
c) secondary transport air is conducted through a slot at the valve plate;
d) immediately thereafter, primary transport air is conducted through a mass of waste so that it is advanced to a valve and onwards out into the pipe system;
e) the valve is closed by lowering the valve plate; and
f) there is closed for the primary transport air first, and immediately afterwards there is closed for the secondary transport air.
At the moments where the valve plate is lifted up from and later is lowered down into the closed position, there is a strong flow of secondary transport air around the valve plate, whereby possible waster material in the valve chamber is entrained and removed with the mixture of primary and secondary transport air.
A valve as disclosed by the present invention may find application in the waste disposal industry, but may also find application in other industries where valves with transport air inlets are used, for example:

The grain and feedstuff industry where grain and the like are transported pneumatically from e.g. storage to lorry and vice versa.
The wood and furniture industry where wooden chips and dust are transported pneumatically from e.g. a machine to a storage and the like.

Alternatively, one may use the valve according to the present invention in wet environments where sewer sludge, suspensions, ensilage and the like are transported. In such cases, the transport system will e.g. be a system where secondary transport air is blown into the pipe system by means of e.g. a pressurised air unit.

Short Description of the Drawing

The invention will now be explained more closely with reference to the accompanying drawing, where:

Fig. 1: shows a side view of a valve according to the invention,
Fig. 2: shows another side view of the valve in Fig. 1,
Fig. 3: shows a detailed section of a pipe joint with a valve plate in movement according to the invention,
Fig. 4: shows a further detailed section of a pipe joint with a valve plate in closed position, and
Fig. 5: shows side views of a valve moving from a closed position to an open position according to the invention.

Detailed Description of the Invention

On Figs. 1 and 2 are shown a valve 1 including a valve chamber 2, a displaceable valve plate 3 and an actuation unit in the form of a cylinder 4.
The valve chamber 2 encloses an outer edge of the two pipe ends 5, 6 which are joined so that an interspace 7 (shown on Fig. 3) appears, and which together with the bottom 8 of the valve chamber 2 and the two pipe ends 5, 6 form a chamber 9 in which the lower edge 10 of the valve plate 3 is disposed when the valve plate 3 is in a first, closed position.
The valve plate 3 is shown in Figs. 1 and 3 in a beginning upwards movement where the valve plate 3 has opened for the mass flow through pipe ends 5, 6.
Cylinder 4 is mounted on the upper part of the valve chamber 2 and is connected with a rod 11 to an upper part of the valve plate 3.
The valve chamber 2 has such a size that the valve plate 3 may be displaced so that it is in a closed first position, where the valve plate 3 guards pipe ends 5, 6, or is in an open second position where the valve plate 3 is lifted up in the valve chamber 2.
At one side 14, the valve chamber 2 is provided with an air inlet 12 arranged to lead secondary transport air down through the valve 1. Air inlet 12 is shown here with a closing arrangement in the form of a screw handle 13 which by turning allows adjusting of the amount of the secondary transport air.
The bottom 8 of the valve 1 is a flange construction which may be dismounted.
Figs. 3 and 4 show a detailed section of an area around the bottom part of the valve chamber 2, where it appears that pipe ends 5, 6 are joined inside valve chamber 2 so that an interspace 7 appears, and that chamber 9 is formed by pipe ends 5, 6 and the bottom 8 of the valve chamber 2.
On Fig. 3 is shown how a secondary transport air A is supplied to the valve chamber 2 and down into the chamber 9, after which primary transport air D passes down under the lower edge 10 of the valve plate 3, where it is mixed with the secondary transport air A, whereby possible waste material in the valve chamber 2 or the chamber 9 is entrained by transport air C which is constituted by the primary transport air D and the secondary transport air A in combination.
On Fig. 4 is shown how the valve plate 3 is provided in a closed position so that it abuts on pipe end 6 and thereby cuts off through-flow of the transport air.
Pipe end 6 has a projection 6a causing valve plate 3 to fit tightly to pipe end 6 and contributing to effectively leading waste material through the valve 1 and onwards into pipe end 6.
When valve plate 3 is in closed position, interspace 7 will be filled, and there will be no possibility of waste material falling down into the chamber 9.
On Fig. 5 is shown a part of a waste suction system 30, including a pipe bend 31, a valve 1 and a pipe section 32, where pipe section 31 is used as waste magazine for waste 33 which has been thrown down through a waste shaft connected to the pipe bend 31.
On the upper view I, the valve 1 is closed and the valve plate 3 is in closed position, and no through-flow of either primary or secondary transport air through valve 1 occurs.
On the centre view II, the valve 1 is activated, and the valve plate 3 is displaced while at the same time through-flow of secondary transport air A occurs through valve 1 via air inlet 12. The secondary transport air A loosens and accelerates the waste 33 and, together with the primary transport air D, will transport the waste 33 away through pipe section 32 in transport air C.
On the lowermost view III, the valve 1 is completely open, and the valve plate 3 is displaced up into the valve chamber 2, and there is free access from pipe bend 31 to pipe section 32. A flow of secondary transport air A still occurs through valve 1 via air inlet 12, so that the waste 33 is loosened and conducted away through pipe section 32.
The invention is not limited to the embodiments shown in the Figures and described above. Other embodiments with other kinds of valves, valve chambers, valve plates, air inlets and/or actuation units are conceivable within the scope of this invention.

Claims

A valve (1) for regulating a mass flow, preferably a mass of waste in a waste suction system (30), including a valve chamber (2), a displaceable valve plate (3) and an actuation unit (4), where the valve chamber (2) at one end is adapted to be disposed between two pipe ends (5, 6), and where the actuation unit (4) is disposed at a second end of the valve chamber (2) and adapted to displace the valve plate (3) in the valve chamber (2) from a closed first position to an open second position, characterised in that the valve chamber (2) is designed with a number of air inlets (12) arranged to lead secondary transport air in through the valve (1).
Valve according to claim 1, characterised in that the air inlets (12) are designed with an adjustable closing arrangement (13).
Valve according to claims 1 - 2, characterised in that the adjustable closing arrangement (13) is coupled to a control.
Valve according to any of claims 1 - 3, characterised in that the air inlets (12) are disposed at one side (14) of the valve chamber (2).
Valve according to claim 1, characterised in that the valve plate (3) is designed in a plastic material.
Valve according to claim 1, characterised in that the valve chamber (2) is designed with inlet connections for the pipe ends (5, 6).
A waste suction system (30), including a pipe system (31, 32), a number of waste shafts and a number of valves (1) according to any of claims 1 - 6, characterised in that the valve (1) is disposed in the pipe system (31, 32) so that the secondary transport air (A) through the air inlet (12) is in downstream flow of a primary transport air (D) through the pipe system (31, 32).
Waste suction system (30) according to claim 7, characterised in that the valve (1) is disposed in the pipe system (31, 32) immediately after a waste shaft.
Waste suction system (30) according to any of claims 7 - 8, characterised in that the valve (1) is disposed in the pipe system (31, 32) at an angular position.
Method for using a valve (1) described in claims 1 - 6 in a waste suction system (30) described in claims 7 - 9, characterised in that emptying a waste shaft (31) is effected according to the following steps:

a) a vacuum is formed in the pipe system (32) provided on the suction side of the valve (1);

b) the valve (1) is opened by lifting the valve plate (3) in a continuous movement;

c) secondary transport air (A) is conducted through a slot at the valve plate (3);

d) immediately thereafter, primary transport air (D) is conducted through a mass of waste (33) so that it is advanced to a valve (1) and onwards out into the pipe system (32);

e) the valve (1) is closed by lowering the valve plate (3); and

f) there is closed for the primary transport (D) first, and immediately afterwards there is closed for the secondary transport air (A).