The present invention relates to a system and method for draining waste in a plumbing system. More particularly, the present invention relates to a system and method for draining waste in a plumbing system using a vacuum system.
Various types of drainage systems are used to direct waste from a source, or a plurality of sources, to a common collection point. For example, gravity feed systems are commonly used in residential and commercial buildings to direct waste to the desired collection point. In a gravity feed system, gravity provides the motive force to move the waste from the source(s) to the collection point. Because gravity is the main motive force, the pipes between the source(s) and the collection point must slope down toward the collection point to maintain the desired flow. However, as the pipes of a gravity system become worn, corroded, roughened, or clogged, gravity alone is sometimes insufficient to move the waste. The requirement that the pipes slope also requires careful planing prior to, and during the construction of a building to assure that the pipes are properly located. This extensive pre-planning makes the addition of pipes or new sources to a completed building difficult.
Vacuum drainage systems offer an alternative to gravity systems. Vacuum systems use a combination of gravity and vacuum to draw waste from the source, or sources, to a collection point. Because the main motive force is vacuum (pressure) rather than gravity, the orientation of the pipes is not significant to the operation of the unit. However, vacuum drainage systems are limited in the height to which they can lift waste and are susceptible to staling during operation.
The present invention provides a vacuum drainage system operable to remove waste from a source. The system includes an accumulator in fluid communication with the source and a substantially vertical riser having a first portion in fluid communication with the accumulator and a second portion downstream of the first portion and in fluid communication with a vacuum source. A first valve is disposed between the first portion and the second portion. The first valve is selectively operable to provide fluid communication between the first portion and the vacuum source. An air inlet is disposed a distance downstream of the first valve and is selectively operable to provide fluid communication between the outside atmosphere and the second portion.
The invention also provides a vacuum drainage system comprising a source of waste and an accumulator in fluid communication with the source and positioned below the source to receive the waste. A vacuum source is operable to provide a vacuum region. The invention also includes a riser having a first portion in fluid communication with the accumulator and a second portion in fluid communication with the vacuum region. A sensor is operable to measure a waste level within the accumulator and an air inlet is operable in response to the waste level within the accumulator to provide fluid communication between the outside atmosphere and the second portion. A first valve is disposed between the first portion and the second portion. The first valve is movable between a first configuration and a second configuration. The first configuration inhibits fluid communication between the first portion and the second portion and the second configuration allows fluid communication between the first portion and the second portion.
The invention also provides a method of transferring waste using a vacuum drainage system. The vacuum drainage system includes an accumulator that receives waste from a source and a riser having a first portion in fluid communication with the accumulator and a second portion in fluid communication with a vacuum source. The method comprises positioning a valve between the first portion and the second portion and providing a selective air flow path between the atmosphere and the second portion. The method also includes sensing a waste level within the accumulator and opening the valve when the waste level exceeds a first predetermined value. The method further includes opening the air flow path to admit air into the second portion of the riser.
In yet another aspect, the invention provides a vacuum drainage system including a vacuum source operable to provide a vacuum region and an accumulator operable to receive a quantity of waste from at least one source. A first riser portion is in fluid communication with the accumulator and a last riser portion is in fluid communication with the vacuum region. An intermediate riser portion is disposed between the first riser portion and the last riser portion and a first valve interconnects the first riser portion and the intermediate riser portion. The first valve is selectively operable to provide fluid communication between the first riser portion and the intermediate riser portion. A first air inlet is selectively operable to provide fluid communication between the outside atmosphere and the intermediate riser portion and a second air inlet is selectively operable to provide fluid communication between the outside atmosphere and the last riser portion.
The description particularly refers to the accompanying figures in which:
Before any embodiments of the invention are explained, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof is meant to encompass the items listed thereafter and equivalence thereof as well as additional items. The terms “connected,” “coupled,” and “mounted” and variations thereof are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings.
With reference to
The collection tank 20 provides a point where the waste can collect. The tank 20 includes a lower drain 40 that allows for the removal of the accumulated waste at periodic intervals or whenever the tank 20 is full. The waste enters the tank near the top where a low-pressure air space 45 is maintained. The vacuum pump 25 also connects to the tank 20 near the top so that operation of the vacuum pump 25 at least partially evacuates the air in the low-pressure air space 45 of the tank 20. The evacuation of air in the low-pressure air space 45 acts to reduce the pressure within the tank 20 and draws air in from the piping 30 attached to the tank 20. In this manner, the vacuum pump 25 is able to produce at least a partial vacuum within a portion of the piping 30 and 70 of the vacuum drainage system 10. It should be noted that the terms “low-pressure” and “vacuum” are used interchangeably herein to describe a region having a pressure below the local atmospheric pressure. Thus, the term “low-pressure” should be understood to mean a region having a pressure below atmospheric pressure. In addition, the term “vacuum” should be understood to include partial vacuums (i.e., any pressure below atmospheric).
An accumulator 50 is in fluid communication with the sink 15 to receive a flow of waste. While a single accumulator 50 is illustrated as being associated with a single sink 15, it should be understood that multiple accumulators could be associated with each source or multiple sources could feed a single accumulator. Waste from the sink 15 flows under the force of gravity to the accumulator 50 where it collects. The accumulator 50 provides a small storage area for waste, thereby allowing for the collection of a larger amount of waste and a longer duration between vacuum applications.
As shown in
As illustrated in
The position of the riser valve 65 relative to the accumulator 50 can effect system operation. Therefore, it is desirable to locate the riser valve no more than four feet above the elevation of the accumulator 50, with lower locations being more preferred. However, it should be understood that many other factors (e.g., pipe diameter, piping arrangement, vacuum pressure, atmospheric pressure, etc.) can effect system performance and will allow systems to function with riser valves 65 located at elevations greater than four feet above the accumulator 50.
As illustrated in
The first tube 85 has an open end positioned within the accumulator 50 such that as the accumulator 50 fills, the end of the tube 85 becomes submerged. Once submerged, the end of the tube 85 is subjected to hydrostatic pressure that varies with the depth of the liquid within the accumulator 50. Thus, the tube 85 is able to measure a pressure change within the accumulator 50 even though the accumulator 50 is exposed to atmospheric pressure.
With reference to
When the air admittance valve 100 is open, air is drawn through an air inlet 115, through the air tube 110, and into the second portion 70 of the riser 55, which is maintained under a partial vacuum by the vacuum pump 25. Thus, the air tube 110 should be formed from a material that is suited to the purpose (e.g., metals, such as copper, steel, stainless steel, or plastics, rubber, composites, ceramics, and the like).
The location in the second portion 70 of the riser 55 at which the air tube 110 penetrates the riser 55 (i.e., the aeration point 120) is not critical. However, it is desirable to position the aeration point 120 as near to the riser valve 65 as possible without interfering with the function of the riser valve 65. A position between 1 inch and 12 inches downstream of the riser valve 65 is preferred.
Turning to
The riser 55a includes a first portion 145, a second portion 150, a third portion 155, and a fourth portion 160. The first portion 145 is in fluid communication with the accumulator 50 and is separated from the second portion 150 by the riser valve 65. The second portion 150 is separated from the third portion 155 by the second air admittance point 120b. The third portion 160 is separated from the fourth portion 165 by the third air admittance point 120c. The fourth portion 165 is in fluid communication with the vacuum portion of the piping 75. It should be noted that in many constructions, the second portion 150, the third portion 155, and the fourth portion 160 are formed from a single pipe. The air admittance points 120 define the break between the portions 155, 160, 165. However, the portions 155, 160, 165 are still formed from a single pipe and, in most constructions, cannot be “separated” from one another.
The aeration points 120a, 120b, 120c receive a flow of air from the independent air admittance valves 100a, 100b, 100c. Each air admittance valve 100a, 100b, 100c is actuated in response to the pressure within the second tube 90 as described with regard to
While the aeration stages 140 of
In another construction illustrated in
With reference to
With the riser valve 65 now open, the first portion 60 of the riser 55 and the accumulator 50 are in fluid communication with the collection tank 20. As such, the low pressure draws the waste out of the accumulator 50 and the first portion 60 of the riser 55 and moves the waste toward the collection tank 20. At the same time, an amount of air is drawn into the second portion 70 of the riser 55 through the air admittance valve 100. The air serves to break-up the waste into an emulsion (air-waste mix) that is more easily lifted by the vacuum. If the waste stalls with the air-admittance valve 100 open, the air entering the second portion 70 will act to push the waste from the aeration point 120 to the vacuum tank 20 while simultaneously breaking-up the waste.
As the waste is drawn out of the accumulator 50, the waste level within the accumulator 50 drops, thereby causing the pressure within the first tube 85 to drop in a similar fashion. Once the pressure within the first tube 85 reaches a predetermined value, the controller 80 actuates and closes both the riser valve 65 and the air admittance valve 100.
The operation of the construction of
The construction of
The construction of
In another system, the air admittance valves 100a, 100b, 100c open and/or close in sequence rather than simultaneously. Timers can be employed to achieve the desired time intervals between the opening and closing of the various valves 100a, 100b, 100c. In addition, other control systems (e.g., microprocessor-based controls, PLCs, relay controls and the like) can be used to control the various valves in the system.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.