Method for controlling a vacuum sewage system for a building or for a marine vessel

Abstract

Method for controlling a vacuum sewage system for a building or for a marine vessel, which includes a vacuum unit (11), vacuum piping (7), a source of sewage (91, 92, 93, 94), and a discharge valve (8) between each source of sewage and the vacuum piping, wherein the vacuum unit generates a predetermined vacuum level in the vacuum piping, in which method the operation of the vacuum sewage system is monitored. In order to ensure an efficiently operating vacuum sewage system, the running time of the vacuum unit is monitored and the vacuum level of the vacuum piping is monitored.

Claims

1. A method of controlling a vacuum sewage system within a building or within a marine vessel, which vacuum sewage system includes a vacuum unit, vacuum piping with at least a main pipe line and at least one branch pipe, at least one source of sewage, and a discharge valve between each of the at least one source of sewage and a respective branch pipe, wherein the vacuum unit generates a predetermined vacuum level in the vacuum piping, the method comprising: monitoring a running time of the vacuum unit; monitoring a vacuum level in the vacuum piping; determining a first given reference value for the running time of the vacuum unit during a predetermined time period during which the running time of the vacuum unit is monitored; and monitoring the vacuum level in the vacuum piping at at least two separate predetermined positions the vacuum piping when a duration of the running time of the vacuum unit is less than the first given reference value.

2. The method of claim 1, further comprising comparing the monitored vacuum levels at the at least two separate predetermined positions with a discharge or flushing sequence of the source of sewage.

3. The method of claim 2, wherein comparing the monitored vacuum levels at the at least two separate predetermined positions with the discharge or flushing sequence of the source of sewage occurs at specific time intervals.

4. The method of claim 1, the running time of the vacuum unit is monitored by a running time meter unit, which registers the running time of the vacuum unit.

5. The method of claim 4, wherein a total registered running time within the predetermined time period is measured in order to determine the first given reference value for said running time.

6. The method of claim 1, wherein the vacuum level is monitored by at least two vacuum sensors placed in each of the at least one branch pipe of the vacuum piping, and in that the vacuum levels indicated by a set of two adjacent vacuum sensors placed in a branch pipe are compared in connection with a discharge or flushing sequence of the source of sewage.

7. The method of claim 1, further comprising monitoring a start-up frequency of the vacuum unit with a counter unit configured to register a number of start-ups of the vacuum unit.

8. The method of claim 7, further comprising registering the number of start-ups of the vacuum unit within a predetermined time to provide a second given reference value for the start-up frequency.

9. The method of claim 8, wherein, when the duration of the running time is greater than the first given reference value or the number of start-ups of the vacuum unit is greater than the second given reference value, the vacuum level is monitored by a vacuum sensor placed at least at one predetermined position of the vacuum piping.

10. The method of claim 9, wherein the vacuum sensor is placed at a sewage source end of a branch pipe.

11. The method of claim 9, wherein the vacuum piping includes a plurality of branch pipes and a vacuum sensor is placed at the sewage source end of each of the plurality of branch pipes, the method further comprising comparing the vacuum levels indicated by the vacuum sensors placed at the sewage source end of each of the plurality of branch pipes.

12. The method of claim 9, wherein the or each branch pipe is closed for a predetermined time by a shut-off valve placed in the branch pipe.

13. The method of claim 1, wherein the vacuum unit comprises one of a vacuum pump, a rotary lobe pump, a liquid ring pump, or an ejector unit.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In the following the invention will be described, by way of example only, in more detail with reference to the attached schematic drawings, in which

(2) FIG. 1 illustrates a general layout of a vacuum sewage system for a building or for a marine vessel in which the method according to the present invention is used,

(3) FIG. 2 illustrates an arrangement for localizing blockage, deposits or layers,

(4) FIG. 3 illustrates an arrangement for localizing leakage, and

(5) FIG. 4 illustrates an alternative arrangement for localizing leakage.

DETAILED DESCRIPTION

(6) FIG. 1 illustrates a general lay-out of a vacuum sewage system 1 for a building or for a marine vessel. In other words, the vacuum sewage system according to the present invention is deployed, or located, as a whole, within a building or onboard a marine vessel. The term building is considered to include housing, hotels, department stores, supermarkets, industrial buildings, etc. The term marine vessel is considered to include yachts, ships, cruisers, freighters, off-shore platforms, etc.

(7) In other words, the present invention relates to a vacuum sewage system, in which all components of the vacuum sewage system are arranged or located within a building or marine vessel. The transport of sewage by vacuum in the vacuum sewage system takes place within the building or the marine vessel. The present invention does not relate to a vacuum sewage system deployed outside a building and collecting and transporting sewage received from the building. In a corresponding manner, the present invention does not relate to a vacuum sewage system deployed outside a marine vessel, e.g. on a quay, for collecting and transporting sewage received from the marine vessel.

(8) The vacuum sewage system comprises a source 9 of sewage, in this embodiment a number of sources of sewage, such as a toilet 91, a urinal 92, a wash basin 93, and a shower 94. The vacuum sewage system further comprises vacuum piping 7 including branch pipes 71, main pipe lines 72 and a collector 73. As indicated in FIG. 1, each source of sewage in the building or onboard the marine vessel, in this example the toilets 91, is individually, in other words separately, connected to the vacuum piping, or in this embodiment to the respective branch pipes 71, through discharge valves 8, which thus are arranged between each of the toilets 91 and the vacuum piping 7. A vacuum unit 11, which in this embodiment is illustrated as a vacuum pump 110, is connected to the collector 73 for generating vacuum and for pumping a flow of sewage in the vacuum piping of the vacuum sewage system. The vacuum unit 1 is further connected to a discharge pipe 12 for discharging the flow of sewage to a receiving facility 13 under atmospheric pressure. The vacuum unit can alternatively also be in the form of e.g. an ejector unit. For a vacuum sewage system onboard a marine vessel, the discharge facility could be e.g. a surrounding sea, a storage tank or a treatment plant. The flow of sewage is in the substantially in the form of sewage water.

(9) Vacuum sewage systems of this kind are well known in the art and by a person skilled in the art and are therefore not discussed in greater deal in this connection.

(10) The direction of the flow of sewage is indicated with block arrows.

(11) FIGS. 2, 3 and 4 illustrate various simplified examples of embodiments of the present invention which will be discussed in detail below. The embodiments include, as discussed above, a vacuum unit 11, vacuum piping 7 with a collector 73 (FIG. 2), a main pipe line 72, a branch pipe 71 and a discharge valve 8. The direction of the flow of sewage is indicated with a block arrow in these figures. The sources of sewage (not shown) are located upstream, in view of the direction of the flow of sewage, of the discharge valves.

(12) The vacuum piping can be subject to leakage. Leakage can be controlled or detected by monitoring the running time of the intermittently operating vacuum unit 11. For this purpose the vacuum unit is provided with a running time meter unit 111 for registering the running time of the vacuum unit.

(13) Alternatively, leakage can also be controlled or detected by monitoring the start-up frequency of the intermittently operating vacuum unit 11. For this purpose the vacuum unit 11 is provided by a counter unit 112 for registering the number of start-ups of the vacuum unit.

(14) In order to achieve more reliable information the vacuum unit 11 can be provided with both a running time meter unit 111 and a counter unit 112, whereby two separate sources of data are made available for the monitoring purpose.

(15) The running time meter unit 111 and the counter unit 112 are both shown in the embodiments of FIGS. 2, 3 and 4, but it is to be understood that they can be used separately or together as found appropriate. The running time meter 111 unit and/or the counter unit 112 are considered to be included also in the general layout of the vacuum sewage system as illustrated in FIG. 1 although they are not specifically referenced.

(16) By monitoring the running time of the intermittently operating vacuum unit the following observations apply. Long running time periods indicate that there is a leakage in the vacuum piping. Short running time periods indicate that the volume of the vacuum piping has decreased, which indicates that a deposit or layer has formed in the vacuum piping. If the start-up frequency is high, this indicates a leakage in the vacuum piping.

(17) The total running time of the vacuum unit 11 registered by the running time meter unit 111 within a predetermined time period is measured. In a corresponding manner, the total number of start-ups of the vacuum unit 11 registered by the counter unit 112 within a predetermined time period is registered.

(18) Given reference values (first given reference value) for the running time can be acquired by carrying out the monitoring within predetermined time periods during e.g. a one month's time when the vacuum sewage system is taken into use, whereby it is still intact, without leakage, and whereby the vacuum piping is still clean or un-contaminated, i.e. without blockage, partial blockage, deposits or layers formed in the vacuum piping.

(19) Given reference values (second given reference value) for the start-up frequency time can be acquired by carrying out the monitoring within predetermined time periods during e.g. a one month's time when the vacuum sewage system is taken into use, whereby it is still intact, without leakage, and whereby the vacuum piping is still clean or un-contaminated, i.e. without blockage, partial blockage, deposits or layers formed in the vacuum piping.

(20) The terms long, short, low and high are thus to be compared to said given reference values and indicate a clear deviation from the given reference values.

(21) Firstly, in other words, if there is a given first reference value for the running time, i.e. a given measured running time, a short, shorter, long, or longer running time indicates that there is a clear deviation in the running time from the reference value vis--vis the given first reference value. It is considered that a person skilled in the art is able to determine, if the deviation fulfils the criteria short, shorter, long, or longer.

(22) Secondly, in other words, if there is a given second reference value for the start-up frequency, i.e. the number of start-ups, a high, higher, low, or lower start-up frequency indicates that there is a clear deviation in the number of start-ups from the reference value vis--vis the given second reference value. It is considered that a person skilled in the art is able to determine, if the deviation fulfils the criteria high, higher, low, or lower.

(23) By establishing a problematic occurrence, e.g. a leakage or a decrease in the volume of the vacuum piping, as discussed above, the localization of the problematic occurrence is facilitated and can be carried out as described in more detail in connection with FIGS. 2-4 below.

(24) If the vacuum sewage system is deployed onboard a marine vessel, the monitoring is advantageously done during night time when the usage of the sources of sewage, such as toilets, is low. In such a case, the monitoring is advantageously carried out during a predetermined time period during the night and on a daily basis, whereby the time period could advantageously be between e.g. 1 a.m. and 5 a.m. onboard time. If the vacuum system is deployed in a building, said time period would be chosen in a corresponding manner, when the usage of the sources of sewage is low.

(25) FIG. 2 shows a first embodiment of the present invention, which provides for a manner for localization of a blockage, partial blockage, deposit or layer in the vacuum piping.

(26) Firstly, the occurrence of a decrease in the volume of the vacuum piping, which indicates that a deposit or layer has formed in the vacuum piping, is considered to have been established based on the running time being short in comparison to the first given reference value as discussed above.

(27) In this embodiment, after the decrease in the volume has been determined, the vacuum level is monitored at least at two separate predetermined positions of the vacuum piping, in this case at three separate positions of a branch pipe 71. A first vacuum sensor P1, a second vacuum sensor P2 and a third vacuum sensor P3 are placed downstream, in view of the direction of the flow of sewage, of the discharge valve 8 in the branch pipe 71. Each source of sewage 8 (not shown) is thus connected individually to a respective discharge valve 8 as discussed above in connection with FIG. 1.

(28) In the operation of the vacuum sewage system, when a toilet, i.e. a source of sewage, is discharged or flushed and the sewage as well as a mass of air is pushed into the branch pipe 71 of the vacuum piping 7, the decrease of the vacuum level in the vicinity of the discharge valve 8 in connection with the discharge or flushing sequence is clear, if the branch pipe is open and clean, i.e. free of any contamination, i.e. blockage, partial blockage, deposit or layer in the branch pipe. Closer to the vacuum unit, i.e. farther away from the discharge valve, the decrease of the vacuum level is moderate.

(29) However, if the branch pipe is contaminated or partially blocked, the decrease of the vacuum level is more radical than in an un-contaminated vacuum piping due to the diminished volume or flow section of the branch pipe due to formation of the partial blockage, deposits or layers in the branch pipe. Closer to the vacuum unit, i.e. farther away from the discharge valve, the decrease of the vacuum level is small, lesser than the moderate decrease with an open clean pipe.

(30) Consequently, by monitoring and comparing the vacuum levels indicated by a set of adjacent vacuum sensors in series of vacuum sensors along the piping, the contaminated part of the piping can be appropriately localized. The number of vacuum sensors can be chosen as desired and is not limited to the example of three vacuum sensors as discussed above.

(31) By using a number of vacuum sensors the contaminated point can be more exactly localized by comparing the vacuum levels indicated by a set of two adjacent vacuum sensors respectively.

(32) FIG. 3 shows a second embodiment of the present invention, which provides for a manner for localization of leakage in the vacuum piping of the vacuum sewage system.

(33) Firstly, the occurrence of leakage is considered to have been determined as described above, either by long running time as compared to a first given reference value or a high start-up frequency as compared to a second given reference value.

(34) In this embodiment, after leakage has been determined, the vacuum level at a predetermined position of the vacuum piping 7 is monitored. A vacuum sensor P is placed at said predetermined position, advantageously at the sewage source end of the branch pipe 71, i.e. immediately downstream, in view of the direction of the flow of sewage, of the discharge valve 8. Each source of sewage 8 (not shown) is thus connected individually to a respective discharge valve 8 as discussed above in connection with FIG. 1.

(35) FIG. 3 shows a vacuum sensor P placed in each of the four branch pipes 71 immediately downstream of the respective discharge valves 8. By comparing the vacuum level measured by the pressure sensor P in each branch pipe 71 the leakage can be localized to a specific branch pipe 71 of the vacuum piping 7.

(36) FIG. 4 shows a third embodiment of the present invention, which provides for an alternative manner for localization of leakage in the vacuum piping of the vacuum sewage system.

(37) Firstly, the occurrence of leakage is considered to have been established as described above in connection with FIG. 3.

(38) In this embodiment, after leakage has been determined, the vacuum level at a predetermined position of the vacuum piping is monitored. A vacuum sensor P is placed at said predetermined position, advantageously at the sewage source end of the branch pipe 71, i.e. immediately downstream, in view of the direction of the flow of sewage, of the discharge valve 8. Each source of sewage 8 (not shown) is thus connected individually to a respective discharge valve 8 as discussed above in connection with FIG. 1.

(39) FIG. 4 shows a vacuum sensor P placed in each of the four branch pipes 71 immediately downstream of the respective discharge valves 8.

(40) At the downstream end of the branch pipe 71, just before the connection of the branch pipe 71 to the main line 72, each branch pipe 71 is additionally provided with a shut-off valve MV. The shut-off valve is advantageously motorized in order to allow for an automatized function. The branch pipe 71 is closed by the shut-off valve MV for a predetermined time, whereby the respective branch pipe 71 is isolated. The vacuum level is measured by the pressure sensor P. If the branch pipe 71 is intact, whereby in other words there is no leakage in the branch pipe, the vacuum level in the branch pipe does not decrease. In case there is a leakage, the vacuum level decreases evenly as a function of time. By monitoring the measured vacuum level the branch pipes can be checked for leakage. This is advantageously carried out in a timed manner so that the vacuum levels are compared at specific time intervals.

(41) The respective monitoring, measuring and registering of the running time and the start-up frequency as well as the respective monitoring, measuring and comparing of the vacuum levels are advantageously carried out by automation, which lies in the competence of a skilled person in the art as is therefore not described in any detail in this connection. The resulting data can then be indicated in an appropriate way in order to provide and to facilitate any required maintenance and repair measures.

(42) The drawings and the description related thereto are only intended for clarification of the basic idea of the invention. The invention may vary in detail, such as to the layout of the vacuum piping, the type of vacuum unit, the number of sources of sewage, the number of monitoring points, the type of running time meter, the type of counter unit, etc., within the scope of the ensuing claims.