Vacuum sewer system

Abstract

The invention relates to a method for transporting waste material in a vacuum sewer system, which includes a source of waste (1), a sewer pipe (2, 21, 22), a first discharge valve (3) between the source of waste (1) and the sewer pipe (1, 21), a second discharge valve (4) in the sewer pipe (2), a waste receiving space and means (100) for generating vacuum into the sewer pipe. Waste is transported in the form of waste slugs, whereby during a first phase, the waste slug is conveyed from the waste source (1) through the first discharge valve (3) into the sewer pipe (2, 21, 22) by way of vacuum, and in a second phase, waste is conveyed further in the sewer pipe (2, 21,22), in the direction of the receiving space. For automatically adjusting the flush cycle according to the waste slug, in the first phase, the pressure flow after the waste slug, higher than said vacuum, is introduced from the location (9) after the first discharge valve (3) to the second discharge valve (4) for closing the same so that the flow through the first discharge valve is stopped, and in the second phase, a vacuum connection to the second discharge valve (4) is activated for opening the same.

Description

[0001] The invention relates to a method for transporting waste material in a vacuum sewer system according to the preamble of claim 1. The invention also relates to a vacuum sewer system.

[0002] This kind of vacuum sewer systems are previously known. However, the noise level related to the flush sequences of the known systems is high. Further, assuring that the source of waste, for example the toilet bowl of the toilet unit, is emptied of all waste requires adjusting of the flush sequence so that it is long enough for letting even larger quantities of waste to be discharged down the drain during the flush sequence, which also has a decisive influence on the noise level.

[0003] An object of the invention is to provide a method by which the above-mentioned disadvantages are avoided and which makes it possible to transport the waste efficiently with simple means. The object is attained by a method according to the invention the main features of which are given in claim 1.

[0004] The basic idea of the invention is to determine the length of the flush sequence automatically according to the amount of waste, i.e. the size of waste batch or discrete waste slug to be transported, in which case the amount of air per flush sequence is constant. When the second discharge valve is closed after the waste batch has been transported through the first discharge valve, the flow, and thereby also the passage of air, via the first discharge valve is terminated.

[0005] The flow through the first discharge valve is accelerating in nature in which case the flow rate increases from the starting moment of the flow, in other words from the beginning of the waste batch, until the flow stops. The so-called after-air subsequent to the waste batch accelerates the flow rate even more in proportion when the flow resistance is smaller. The flow resistance is in direct proportion to the noise level.

[0006] In the present invention, the amount of after-air passing through the first discharge valve is optimized, particularly minimized, in which case the flow rates decrease, which lowers the noise level significantly. Further, the function of the flush or discharge sequence is pneumatically controlled with a control means by using vacuum prevailing in the vacuum sewer system.

[0007] The closing of the second discharge valve is preferably controlled in a way that with the control means, the connection of the vacuum to an auxiliary valve for opening thereof it is activated, so that a flow connection is formed between the waste batch passing location after the first discharge valve and the second discharge valve, in which case the auxiliary valve is closed after a predetermined time since the waste batch flow through the first discharge valve has stopped.

[0008] The control means advantageously activates also the connection of the vacuum to the first discharge valve for opening of the same, in which case the closing takes place after a predetermined time since the waste batch flow through the first discharge valve has stopped.

[0009] Further, the control means advantageously activates the connection of the vacuum to the rinse water valve for opening of the same, in which case the rinse water valve is closed after a predetermined time subsequent to the closing of the first discharge valve.

[0010] For increasing the discharge efficiency of the system, there is also an aeration valve preferably connected to the sewer pipe, in which case the control means can advantageously activate the connection of the vacuum to the said aeration valve for opening the same after a predetermined time subsequent to the opening of the first discharge valve for passing transport air into the sewer pipe, in which case the aeration valve is closed after a predetermined time subsequent to the opening of the second discharge valve.

[0011] The predetermined times related to the above-mentioned valves are advantageously controlled with the help of flow restrictors in connection with the control means and said valves. The flow restrictors are advantageously nozzles, whereby by changing their dimensions, the desired time effect can be obtained. Naturally, as an alternative, an adjustable valve arrangement can be used.

[0012] The present invention further relates to a vacuum sewer system, the main features of which are given in claim 11. Preferred embodiments of the vacuum sewer system are given in claims 12 to 18.

[0013] In the following, the invention will be described more in detail, by way of example only, with reference to the enclosed schematic drawing.

[0014] The drawing represents a section of the vacuum sewer system which includes a source of waste, in this example a toilet unit 1, a sewer pipe 2, which comprises a first section of the sewer pipe 21 and a second section of the sewer pipe 22, a first discharge valve 3 between the toilet unit 1 and the first section of the sewer pipe 21 as well as a second discharge valve 4 in the sewer pipe 2, i.e. between the first section of the sewer pipe 21 and the second section of the sewer pipe 22. The second section of the sewer pipe 22 leads to a waste receiving space, not shown in the drawing. The vacuum sewer system further includes a means for generating vacuum in the sewer pipe 2, which means has been represented only as a reference by an arrow 100.

[0015] A control system is connected to the toilet unit 1 which automatically controls the length of the toilet unit 1 flush cycle according to the amount of waste transported from the toilet bowl 11 to the sewer pipe 2.

[0016] The control system includes a control means 5, from which there is a flow connection, by means of tube means, to the second section of the sewer pipe 22, which is under a constant vacuum maintained in the vacuum sewer system. The flow connection is arranged at a location 6 situated after the second discharge valve 4, i.e. on the waste receiving side of the second discharge valve 4. Correspondingly, there is a flow connection from the control means 5 to an aeration valve 7 and an auxiliary valve 8 connected to the first section of the sewer pipe 21. Further, a flow connection by means of a tube means is arranged from the control means 5 to the first discharge valve 3 and to a rinse water valve 10 of the toilet unit. A pneumatic activator means 12 is connected to the control means 5 by means of the tube means forming the flow connection.

[0017] A first tube means 51 between the control means 5 and the second section of the sewer pipe 22 is joined to a second tube means 52 between the auxiliary valve 8 and the second discharge valve 4 by means of a first tube portion means 71, in which a first flow restrictor 31 is arranged. The first tube means 51 has a first non-return valve 41 and a second non-return valve 42 arranged on opposite sides of the connection location of the first tube portion means 71.

[0018] A second tube portion means 72 leading to valve 7, which branches off a third tube means 53 leading from the control means 5 to the auxiliary valve 8 is provided with a second flow restrictor 32.

[0019] In the rinse water valve 10 there is arranged a third flow restrictor 33 and in the control means 5 there is arranged a fourth flow restrictor 34.

[0020] The above-mentioned flow restrictors 31, 32, 33 and 34 are preferably nozzles in which case, by changing the dimensions of the nozzles, the desired effect can be provided. Alternatively, the adjustable valve arrangement can be used.

[0021] The vacuum sewer system according to the example has the following operation principle.

[0022] When the toilet unit 1 is in state of rest the first discharge valve 3 is closed. The aeration valve 7 and the auxiliary valve 8 connected to the first section 21 of the sewer pipe 2 are also closed. The auxiliary valve 8 is a diaphragm valve, which in a closed-position shuts off the connection between the second tube means 52 and an eight tube means 58 and which correspondingly opens said connection when it is in an open-position. The second discharge valve 4 is open because it is connected to the sewer pipe 2 (more exactly to the second section 22 of the sewer pipe 2, which is under the vacuum maintained in the vacuum system) through a connection formed by the first tube portion means 71 and the second tube means 52.

[0023] When the toilet unit 1 has been used and there is waste accumulated in the toilet bowl 11, the intention is to flush the waste down to the sewer pipe 2 and the flush sequence is activated by affecting the pneumatic activator means 12. This can preferably be for example a flush button in connection with a bellows system, which by pressing the flush button provides an air pulse through a fourth tube means 54 to the direction of the control means 5.

[0024] The air pulse created by the pneumatic activator means 12 is arranged to affect the control means 5 in such a way that the vacuum is connected from the sewer pipe 2 via the first tube means 51 to the first discharge valve 3 through a fifth tube means 55 connected thereto, in which case the first discharge valve opens up. Correspondingly, the vacuum is connected to the auxiliary valve 8 through the third tube means 53, to the rinse water valve 10 through a sixth tube means 56 and to the aeration valve 7 through the third tube means 53 and the second tube portion means 72, in which case the said three valves open up as well. The aeration valve 7 is arranged to open with a predetermined delay under the influence of the second flow restrictor 32.

[0025] When the first discharge valve 3 has opened, the ambient air pressure prevailing in the toilet bowl 11 pushes the waste in the bowl and rinse water into the sewer pipe 2 maintained under vacuum through the discharge valve 3. In such a vacuum sewer system the waste displaces or moves along intermittently and in the form of so-called waste batches or discrete waste slugs, which fill up the diameter of the sewer pipe completely. This also means that the waste slugs are followed by a pressure front higher than said underpressure.

[0026] To a predetermined location 9 of the sewer pipe 2, in other words to the first section of the sewer pipe, preferably almost immediately after the first discharge valve 3, a flow connection is arranged to the auxiliary valve 8 by means of the eight tube means 58. When the waste slug passes this location 9, the pressure front in question causes a sudden increase in pressure which moves under the influence of the said vacuum control of the eight tube means 58 through the auxiliary valve 8 in its open-position and further via the second tube means 52 to the second discharge valve 4 and closes it. Therefore, the flow through the first discharge valve 3 stops.

[0027] When the predetermined control period of the control means 5, i.e. in practice the prolonged vacuum effect provided by the fourth flow restrictor 34, ends, the ambient air pressure is connected to the tube means 53, 72, 55 and 56 and it has an effect on the first discharge valve 3, the auxiliary valve 8, the aeration valve 7 and the rinse water valve 10, in which case the first discharge valve 3 and the auxiliary valve 8 close up almost immediately. The aeration valve 7 and the rinse water valve 10 on the other hand stay open for a while because of the second flow restrictor 32 and the third flow restrictor 33 arranged therewith. By extending the opening time of the rinse water valve 10 there is a water mirror provided in the toilet bowl 11 for the next flush cycle. There is a flow connection from the rinse water valve 10 to the toilet bowl 11 of the toilet unit 1 by means of a seventh tube means 57.

[0028] Because the auxiliary valve 8 has closed up, in other words it is in its closed-position, there is air discharging (to the direction of the vacuum affecting the second section of the sewer pipe 22) through the first flow restrictor 31 (via the connection created by the second tube means 52, the first tube portion means 71 and the first tube means 51), in which case the second discharge valve 4 opens up again under the vacuum directed thereto. However, the aeration valve 7 is still open (under the influence of the second flow restrictor 32), in which case there is transport air further helping the transportation of the waste slug flowing into the first section of the sewer pipe 21, whereby the waste is forced into the second section of the sewer pipe 22 and further into the waste receiving space. After a time predetermined by the second flow restrictor 32, the aeration valve 7 closes up after which the flush or discharge cycöe has been completed and the section of the vacuum sewer system in question has returned to the above-mentioned state of rest for a new flush or discharge period.

[0029] According to what has been represented above, the first, second, third and fourth flow restrictors 31, 32, 33 and 34 are preferably nozzles so that with the dimensions of the nozzles, the control of the vacuum sewer system can be affected as desired.

[0030] The opening time of the discharge valve 3 is adjusted with the fourth nozzle 34 of the control means 5. This control also affects the opening time of the rinse water valve 10, the auxiliary valve 8 and the aeration valve 7. A smaller nozzle extends the vacuum duration of action, in other words the opening time of said valves.

[0031] The feeding time and amount of the auxiliary transport air is controlled with the second nozzle 32, in which case a smaller nozzle adds to the feeding quantity of the transport air by keeping the aeration valve 7 open for a longer time.

[0032] The first nozzle 31 on the other hand has the following effect on the operation of the second discharge valve 4. A smaller nozzle speeds up the closing up of the valve and therefore it is possible to influence the amount of air driven with the waste slug through the toilet bowl 11 of the toilet unit 1. In known vacuum sewer systems in which the flush cycle remains constant, the amount of air conveyed to the sewer pipe 2 varies according to the quantity of the waste slug. In the system according to the present invention said air amount per flush cycle is always constant. A further advantage of this arrangement, in addition to the above-mentioned benefits, is that the capacity of the vacuum sewer system is more easily dimensioned, which also facilitates the control of the system.

[0033] The level of the water mirror is adjusted in the toilet bowl 11 by means of the third nozzle 33 of the rinse water valve 10. The total water amount is determined by interaction of the third 33 and the fourth nozzle 34 in which case smaller nozzle dimensions increase the amount of the fed rinsing water by prolonging the opening time of the valve.

[0034] The above description and the drawing attached thereto are only intended to clarify the basic idea of the invention. The method and system according to the invention may vary within the ensuing claims.

Claims

1-18. (canceled)

19. A method for transporting waste material in a vacuum sewer system including a source of waste, a first discharge valve between the source of waste and the sewer pipe, a second discharge valve in the sewer pipe, a waste receiving space, and means for generating vacuum in the sewer pipe, wherein the waste material is transporting in the form of slugs, the method comprising:

a first phase in which the waste slug is transported from the source of waste through the first discharge valve into the sewer pipe by way of vacuum; and

a second phase in which the waste slug is further transported along the sewer pipe toward the receiving space;

wherein during the first phase, a pressure after the waste slug higher than the vacuum is communicated from a predetermined location downstream of the first discharge valve to the second discharge valve for closing the second discharge valve, thereby stopping flow through the first discharge valve; and

wherein during the second phase, a vacuum connection to the second discharge valve is activated for opening the second discharge valve, thereby to advance the waste slug further along the sewer pipe by vacuum.

20. A method according to claim 19, in which a vacuum connection to an auxiliary valve is activated by a control means for opening the auxiliary valve so that a flow connection is formed between the predetermined location downstream of the first discharge valve and the second discharge valve.

21. A method according to claim 20, in which the auxiliary valve is closed after a predetermined time after waste slug flow through the first discharge valve has stopped.

22. A method according to claim 21, in which the predetermined time for closing the auxiliary valve is controlled by a flow restrictor.

23. A method according to claim 19, in which a vacuum connection to the first discharge valve is activated by a control means.

24. A method according to claim 23, in which the first discharge valve is closed after a predetermined time after waste slug flow through the first discharge valve has stopped.

25. A method according to claim 24, in which the predetermined time for closing the first discharge valve is controlled by a flow restrictor.

26. A method according to claim 19, in which a vacuum connection to a rinse water valve is activated by a control means to supply rinse water to the source of waste.

27. A method according to claim 26, in which the rinse water valve closes after a predetermined time after the first discharge valve closes.

28. A method according to claim 27, in which the predetermined time for closing the rinse water valve is controlled by a flow restrictor.

29. A method according to claim 19, in which a vacuum connection to an aeration valve in fluid communication with the sewer pipe is activated to open the aeration valve after a predetermined time after the first discharge valve opens, thereby to supply transport air into the sewer pipe.

30. A method according to claim 29, in which the aeration valve is closed after a predetermined time after the second discharge valve is opened.

31. A method according to claim 30, in which the predetermined time for closing the second discharge valve is controlled by a flow restrictor.

32. A vacuum sewer system comprising:

a source of waste;

a sewer pipe;

a first discharge valve disposed between the source of waste and the sewer pipe;

a second discharge valve disposed in the sewer pipe;

a waste receiving space in fluid communication with the sewer pipe;

a vacuum generator in fluid communication with the sewer pipe; and

a flow connection communicating between a first section of the sewer pipe at a predetermined location downstream of the first discharge valve and the second discharge valve.

33. A vacuum sewer system according to claim 32, in which the flow connection includes an eighth tube means between said predetermined location of the sewer pipe and an auxiliary valve and a second tube means between the auxiliary valve and the second discharge valve, wherein the system further includes a control means, a third tube means between the auxiliary valve and the control means, and a fourth tube means between the control means and a second section of the sewer pipe downstream of the second discharge valve.

34. A vacuum sewer system according to claim 33, further comprising a fifth tube means between the first discharge valve and the control means.

35. A vacuum sewer system according to claim 34, further comprising a rinse water valve in fluid communication with the control means through a sixth tube means, wherein the rinse water valve is further in fluid communication with the source of waste through a seventh tube means.

36. A vacuum sewer system according to claim 35, further comprising an aeration valve in fluid communication with the control means through a third tube means and a second tube portion means, and the aeration valve is in fluid communication with the first section of the sewer pipe.

37. A vacuum sewer system according to claim 36, in which the first tube means and second tube means are connected to each other by a first tube portion means having a first flow restrictor, a second flow restrictor is attached to the aeration valve, a third flow restrictor is attached to the rinse water valve, and a fourth flow restrictor is attached to the control means.

38. A vacuum sewer system according to claim 37, in which each of the flow restrictors comprises a nozzle.

39. A vacuum sewer system according to claim 37, in which each of the flow restrictors comprises an adjustable valve.

40. A vacuum sewer system according to claim 33, further comprising a pneumatic activator means connected to the control means through a fourth tube means.