Vacuum accumulator connected to a suction pipe

Abstract: Vacuum accumulator incorporating a vacuum vessel (15) for communication with a suction conduit (6), and with at least one vacuum accumulator vessel (20)interconnectable therewith via a stop valve (19), in turn connected to a vacuum pump (23) for charging of said vessels (15 and 20) with a vacuum under a limited volume, whereby the stop valve (19) is adapted to open more and more when the vacuum in the vacuum vessel (15) drops to a certain volume.

Description: The present invention refers to waste treatment by aid of suction. At transport of waste of different kinds with aid of suction it is often used continuous suction, which certainly means a very large energy consumption, and which also means a need for big and expensive vacuum pumps. For intermittent transport it however also is required rather large and therefore expensive vacuum vessels and vacuum pumps, as the suction must be maintained during a time of several seconds, which means a need for a rather big volume of vacuum. Primarily the invention refers to a vacuum accumulator by aid of which the size and capacity of required vacuum pumps and tanks can be reduced to a substantial degree with maintained extended suction time. GB-A-1342097 refers to a refuse disposal system having a vacuum accumulator that incorporates a vacuum vessel arranged to communicate with a suction conduit and with a vacuum accumulator vessel connected to the vacuum vessel via a stop valve, which vacuum accumulator vessel is connected to a vacuum pump. Hereinafter the invention will be further described with reference to an illustratory embodiment shown in the accompanying drawings. Fig. 1 illustrates schematically the design of a vacuum accumulator according to the invention. Fig. 2 shows an end view from the left hand side of a waste removal device suitable for connection to the vacuum accumulator according to the invention. Fig. 1 shows a vacuum accumulator, which can be used where there is a desire to minimize operating and investment costs but still a need for a vacuum during a certain period of time, and in which is arranged a suction duct 6. The duct 6 is preferably provided with a first stop valve 14. The duct is connected to a columnar vacuum container 15, which at the upper end is equipped with a number of filters/dewatering tubes 16, and has a tube line 17 extending from the top thereof. In this tube line 17 there is preferably arranged a by-pass conduit 18 with a second stop valve 19 before the tube line 17 is connected to an accumulating vacuum vessel 20. The accumulator vessel 20 is further, via a conduit 21 having an adjustable valve 22 provided therein, connected to a vacuum pump 23 driven by a motor 24 and equipped with an outlet 25. By means of such an arrangement it is possible to charge both vessels 15 and 20 with vacuum of e.g. 70-90%, with quite a small vacuum pump 23. At start of the rather short suction procedure required for the device according to the invention, the valve 19 is closed and the valve 14 is opened, whereby a short inflow of air through the duct 6 into the vacuum vessel 15 occurs, which gives a suction effect in the duct 6 and thereby in a device connected to the suction duct 6. Hereby the vacuum in the vacuum vessel 15 is continuously reduced. A proper through-flow of about 50-60 m/s for the intended application field can be set after the first jerk-like moment by proper dimensioning. When the vacuum in the vessel 15 has been reduced to a certain level, where the desired flow can not be maintained any longer, the valve 19 is opened, whereby the vacuum in the accumulator vessel 20 causes that the desired volume of flow, which is sufficient for maintaining transport of goods in a device coupled to the vacuum accumulator, can be maintained a further period of time time. The valve 19 thereby in a manner known per se is designed thus that its opening condition is dependent of the remaining vacuum in the vacuum vessel 15, i.e. as the vacuum in the vessel 15 drops, the valve 19 is opened more and more. In this manner it is possible with comparatively inexpensive vessels and a vacuum pump of rather low capacity to obtain suction periods of about 10 seconds and more at the above-mentioned desired flow. In the shown sketchy design the device has been shown with a vacuum vessel 15 and an accumulator vessel 20, but it is of course possible to increase the suction capacity and performance by connecting more accumulator vessels in the system if so is required and desired. The invention is not limited by the embodiment illustrated in the drawing and described in connection thereto but modifications and variations are possible within the scope of the appended claims. In Fig. 2 is schematically illustrated a device for dewatering and removal of waste material, which can preferably be connected to the suction conduit 6 from the vacuum accumulator according to the invention, and this device incorporates a transport gutter 1, which can be constituted, e.g. by a conveyor or can be a portion thereof, and in which the material, primarily food waste, which shall be dewatered and transported away is supplied from the left hand side in the drawing. At the right hand side the gutter 1 opens in a collecting hopper 2, provided in a housing 3. The collecting hopper 2 has a cross section narrowing in a direction from above and downwards and its thus inclined walls 4 are wire walls, or walls otherwise designed for allowing liquid passage. At the lower part of the hopper 2 this is also provided with a bottom 5 which is liquid permeable and the interior portion above the bottom is connected to the vacuum duct 6. The bottom 5 in the collecting hopper 2 is situated at a level above the lower wall 7 of the housing 3, which slopes towards the centre and one side, where a conduit 8 is connected for discharging liquid, which has drained off from the material collected in the collection hopper and passed the liquid permeable walls 4 and bottom 5 of the collecting hopper. At a distance above the bottom 5 of the collection hopper there is provided a plate 9 designed as a pivotable valve, with a substantially horizontal pivot shaft 10 supported in the walls of the collecting hopper. This plate 9, acting as a rotary valve, is dimensioned to cover, in its horizontal normal position, the cross section of the collecting hopper 2 and thereby prevent material fed down into the collecting hopper from reaching the bottom 5 of the hopper. In the embodiment shown the plate 9 is pivotable by influence of an actuator 11, e.g. an air cylinder, an electric rotary actuator, or the like. This actuator 11 can be adapted to initiate pivoting of the plate 9 at certain time intervals under governing from a control device not further shown, and/or can be manually brought to effect a pivoting of the plate 9 by actuation of a control. The housing 3 of the device at one side is provided with a removable cover 13 for making possible a simple rinsing and cleaning of the interior of the device. This device operates in the following manner: Trays or the like (which are not shown in the drawings), on which rest food waste, napkins and the like, are transported along the gutter 1 towards the housing 3. At the upper end of the collecting hopper the trays are emptied in appropriate manner, e.g. by not shown scrapers, by not shown rockers or the like, thus that the material on the trays is emptied into the collecting hopper 2. The plate 9 in its neutral position is in its substantially horizontal position, covering the cross section of the hopper and preventing the down-falling material from reaching the bottom 5 of the collecting hopper. In this position with the material resting on the plate 9, liquid in the material will flow out and be drained via the liquid permeable walls 4 of the hopper. This liquid flows down onto the lower wall 7 of the housing, where it is led away through the conduit 8. After a proper dwell time in relation to the volume of material supplied on this plate 9, the material collected thereon is brought to fall into the lower portion of the hopper in that the actuator 11 is activated either via the time control or manually, thus that the plate 9 is pivoted preferably 180°, and eventually to a substantially vertical position, whereby the material falls down into the space below the plate 9 in the hopper 2. At the pivoting through 180° or after return of the plate 9 to its position covering the cross section of the hopper, by influence of the actuator 11, further material can be gathered upon the plate 9. After a dwell time of e.g. 2 minutes for the material, which has fallen down below the plate 9, during which time further dewatering occurs, the duct 6 opening in the lower portion of the hopper is subjected to a suction effect, which is maintained during a certain time for sucking out the material in the space below the plate 9 to a not shown station for taking care of or treating the material, which thus has been dewatered.

Claims: A vacuum accumulator that incorporates a vacuum vessel (15) arranged to communicate with a suction conduit (6), and with a vacuum accumulator vessel(20) connected to the vacuum vessel via a stop valve (19), which vacuum accumulator vessel (20) is connected to a vacuum pump (23), characterized therein , that the vacuum pump (23) is adapted to keep said vessels (15 and 20) charged with a vacuum under a limited volume, and that the stop valve (19) is adapted to open to a bigger extent when the vacuum in the vacuum vessel (15) has dropped to a certain volume. A vacuum accumulator as claimed in claim 1, characterized therein , that a by-pass conduit (18) is provided to bridge the stop valve (19).

Inventors: KIHLSTROEM CHRISTER, KIHLSTROEM, CHRISTER, Kihlström, Christer
Applicants: CENTRALSUG AB
Application year: 1995
Main classification: B65F5
IPC codes: B65F5