US3115148A - Sewerage systems - Google Patents

Description

Dec. 24, 1963 s. A. J. LILJENDAHL SEWERAGE SYSTEMS 5 Sheets-Sheet l Filed May 2'7, 1959 Dec. 24, 1963 s. A. J. LILJENDAHL SEWERAGE SYSTEMS 5 Sheets-Sheet 2 Filed May 27, 1959 Dec. 24, 1963 s. A. J. LILJENDAHL 3,115,148

SEWERAGE SYSTEMS I Filed May 2'7, 1959 5 Sheets-Sheet 5 Dec. ,24, 1963 s. A. J. LILJENDAHL 3,11

SEWERAGE SYSTEMS Filed May 27, 1959 Q 5 Sheets-Sheet 4 Dec. 24, 1963 s. A. J. LILJENDAHL 3,115,148

SEWERAGE SYSTEMS Filed May 27, 1959 5 Sheets-Sheet 5 nxwaezuxmimmxmuuwmw i. 9338 United States Patent ()filice 3,115,148 Patented Dec. 24, 1963 3,115,148 SEWERAGE SYTEMS Sven Algot Joel Liliendahl, Gyllenstiernas Vag 8, Staket, Sweden Filed May 27, I959, Ser. No. 816,130 Claims priority, application Sweden May 28, 1958 7 Elairns. (Cl. 137-2tl5) The present invention relates to improvements in sewerage systems of the kind in which waste products discharged from water-closet bowls, urinals and like sanitary apparatus are conveyed away separately and distinctly from the waste products or effluents conveyed away from bath tubs, wash basins, sinks and the like. The eflluents from the last-mentioned class of apparatus will be referred to hereinafter briefly as waste water, while the efiluents from the first class of apparatus will be referred to as Waste.

In systems of the kind referred to it is a desideratum to be able to transport waste from water-closets and the like together with as small as possible an amount of water. Plants meeting these requirements are previously known to the art, for instance in my Belgian patent specification No. 557,284, the transportation being effected in such plants by the aid of an air-pressure difiference between the sanitary apparatus, on the one hand, and a closed sewage receptacle within which a vacuum prevails, on the other hand, said air pressure difference becoming elfective on the opening of an outlet valve near the sanitary apparatus in question.

The above-mentioned Belgian patent specification does not disclose how the contents of each such sewage receptacle, hereinafter termed a local receptacle, can be removed and forwarded therefrom. It has been suggested in the said patent specification that such removal could be carried out by road vehicles, for example. This method, however, may involve several drawbacks both from a sanitary and from an economical point of view.

The present invention has for its principal object the provision of a sewerage system of the kind referred to in which the sewages derived from sanitary apparatus are transported all the way from one or more local receptacles to a terminal station, where the sewage is either made use of, for instance for the production of more suitable forms of fertilizing material, or decomposed. This object is achieved, according to the invention, by providing means for forwarding the sewage collected in one or more local receptacles to a main receptacle, such forwarding means comprising conduits interconnecting said receptacles, and also providing means for propelling the sewages through said conduits.

Another object of the invention is to establish favourable conditions for an effective and economical carrying away of the only slightly impuri-fied waste water.

Still another object of the invention is to coordinate the transportation of the two kinds of waste products in a novel way.

Further features of the invention will appear from the following detailed description of a few embodiments given by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a schematic illustration of a land-area, such as a municipality or part thereof, or any other municipal unit having a common sewage outlet for that portion, at least, of the sewerage system through which refuse originating from water-closet bowls and like apparatus is conveyed. In the figure a number of arbitrarily chosen contours have been inserted which indicate the topographic conditions of the area;

FIGURE 2 indicates the projection in a vertical plane of the conduits drawn in FIGURE 1;

FIGURE 3 shows a local receptacle constructed in accordance with the invention;

FIGURE 4 shows, on a larger scale, a vertical section through a structure associated with a local receptacle;

FIGURE 5 illustrates an auxiliary equipment associated with a local receptacle;

FIGURES 6 and 7, respectively, illustrate modified forms of a device forming part of the equipment shown in FIGURE 5;

FIGURE 8, also in a highly schematic form, shows an arrangement forming part of the waste-Water section of the system;

FIGURE 9 is a fragmentary plan view of the arrangement of FIGURE 8;

FIGURES 10 to 12 show details the purpose and nature of which will be described in detail hereinafter;

FIGURE 13 is a cross-section through a covered ditch containing conduits laid out in accordance with the invention;

FIGURE 14 is a cross-section similar to that of FIG- URE 13;

FIGURE 15 shows a cross-section through an open ditch which carries waste water draining from the system;

FIGURE 16 shows a detail, and

FIGURE 17 illustrates a special arrangement according to the invention.

Referring to FIGURE 1, each circle A may be considered to represent, for example, one large building or a plurality of smaller buildings situated comparatively close to each other, the closet bowls and similar sanitary apparatus of which communicate through one or more building conduits S with a local receptacle LB These local receptacles LB in turn are connected by main sewer conduits E to a main receptacle HB at a sewerage terminal B common to the sewerage system serving the district. As shown in the figure, the local receptacles LB may be connected to the main receptacle through conduits connected in parallel or in series with each other. A combination of these two methods is also possible, i.e., some of the local receptacles may be connected in parallel with a local receptacle situated nearer the main receptacle, the latter local receptacle communicating with the main receptacle of the sewerage terminal directly or in series with still other such local receptacles, etc.

The broken lines BDT indicate the waste water conduits of the system. The said conduits, which in the embodiment shown are only partly routed together with the main sewer conduits E, discharge into an open ditch D or any other natural receiver. The waste water conduits BDT, too, preferably originate from local receptacles LB which are supplied in an analogous mannor by building Waste water discarge conduits S to which a plurality of apparatus such as wash basins, bath tubs and the like are connected.

Waste is discharged from each building conduit S into the associated local receptacle LB by creating a vacuum in the local receptacle, resulting in a pressure diiierence between the conduit and the local receptacle. The vacuum in each local receptacle L'B may be achieved, for example, by an individual vacuum pump (not shown) that is coupled to the receptacle. This is assumed to be the case with the receptacles LE in the systems A and A of FIG. 1. Alternatively, a central source of vacuum VK located in the sewerage terminal B may be employed to provide the vacuum in all the local receptacles. Such is the case with the local receptacles LB in the systems A A and A of :FIG. 1, which are coupled to the source VK via vacuum lines V. The vacuum source VK is also coupled to the main receptacle HR to provide a vacuum therein that is useful for drawing sewerage through the conduits E and E in similar fashion, or by utilizing gravity, waste water is discharged from the building conduits S into the associated waste water local receptacles LB Where a natural slope exists between a local receptacle LB and the main terminal receptacle 1-18, the transportation through the conduit between these collecting stations can take place by gravity, without any special arrangements. This is assumed to be the case with respect to the main sewer conduit section E. On the other hand, where the transportation cannot be elfected exclusively by gravity, which most commonly is the case, then, according to the invention, the transportation is accomplished instead by creating a pressure difference between the local and main terminal receptacles. According to this invention such pressure difference may be established by creating in the main receptacle HE a vacuum greater than that existing within the local receptacles LE or by placing the receptacles LE intermittently under pressure to discharge their contents into the main sewer conduits E. A combination of both principles is also possible. The symbol K indicates a compressor which is connected through a compressed-air line TL to two of the local receptacles LB which are assumed to be situated at such a level relative to that of the main receptacle that it would be impossible to attain the transportation required exclusively by maintaining a vacuum within this receptacle.

The disposition of the above-mentioned conduits as projected on vertical planes is illustrated in PEG. 2.

FIGURE 3 shows diagrammatically an axial section through a local sewage recetpacle LB to which a plurality of building conduits S coming from apparatus such as closet bowls are connected. Connected to the local receptacle at its bottom is the drain conduit E serving for forwarding the excrements et cetera received in the local receptacle to the main receptacle. Numeral 1 designates devices associated with each building conduit S at its outlet into the local receptacle LE one such device being shown on a larger scale in FIGURE 4. The device 1 essentially comprises two cylinders 2 and 6, the cylinder 2 of which is in direct communication with the building conduit S as shown, and contains a plunger 3 serving as a valve cone. The mouth of the conduit S situated within the receptacle or tank LB is normally closed off by a valve disc i which may be provided, for example, with a counterweight 5, this weight being so dimensioned and mounted so as to allow the valve to be opened on a predetermined pressure increase occurring within the conduit S by the action of opening a valve at one of the sanitary apparatus connected thereto. The cylinder 6 of the device contains a piston 7, and the space above this piston communicates through a restricted orifice 8 and a pipe 9 with the conduit S either adjacent the local receptacle or tank LE as shown in the drawing, or at a point near the opposite end of the building conduit S The piston '7 is retained in its upward position by virtue of the vacuum normally existing in pipe 9, atmospheric pressure being applied at all times to the face of the piston 7 that is exposed to the open end of the cylinder 6, thus urging the piston 7 upwardly. The piston 7 has a piston rod ltl' formed with a longitudinally extending slot 11 which is engaged by a pin 12 on a rod 13 carrying the plunger 3. The various parts are shown in their normal or neutral positions, and the plunger 3 is prevented from sliding downward by gravity because its pin 12 is supported on one arm of a latch pawl 14 having a second arm which is loaded by a leaf spring 15.

If, for example, because of leakage, wrong manipulation of associated apparatus, or for any other reason, an inflow of air into the building conduit S should occur for a duration of time considerably in excess of the normal open period of the discharge valve of such apparatus, then air will flow through the pipe '9 and orifice 8 and enter the cylinder s above the piston 7, thus destroying the pressure diiierence that retained the piston 7 in its upward position and allowing the piston to move slowly downward causing relative movement to take place between the slot 11 and pin 12. if, during this movement, the cause of the failure is removed so that the extended inflow of air is interrupted, then the positive pressure above the piston '7 will decrease causing the piston to return to its neutral position. On the other hand, if said inllow of air should continue for a period several times longer than the normal open period of the discharge valve of a closet bowl, for example, then a projection 16 provided on the piston rod ltl will finally engage the latch pawl 14 and will pivot the latter against the action of the spring 15 to disengage the pawl from the pin 12, whereby the plunger 3 will drop down and cut off the communication between the receptacle LB and the conduit S so that the vacuum. within the receptacle LB will not be lost. However, when the extended or abnormal air inflow has ceased, then the air entrapped within the conduit S is evacuated through a restricted by-pass 1'7 fonmed through the plunger 3. This by-pass, of course, is also effective when the plunger valve was closed, but the rate of air inflow through the same is insignificant as compared with the amount of air which would flow into the receptacle in the absence of the plunger 3. The evacuation of the air in the pipe 9 and in the space above the piston 7, of course, takes place in the same way. Upon completion of this evacuation, the piston will return to its uppermost position because of the pressure diiference between the faces of the piston and will now carry with it the valve plunger 3. immediately before the neutral position has been reached, the pin 12 will reengage the latch pawl 14.

The valve 4 has an important function if two or more pipes S lead to a common local receptacle LB The check valves 4 serve to prevent the destruction of vacuum in one or more of the pipes S in the event the air pressure in the local receptacle LE should rise suddenly above a predetermined value due to a sudden onrush of large quantities of air from another pipe S which is leaking and which has not yet been shut off from the receptacle LE by its plunger 3. Upon such a pressure increase in the receptacle, the valves 4 to the other pipes S close, retaining the vacuum formerly existing in these other pipes.

If, in accordance with one particular embodiment of the invention, the local receptacle LB is discharged into the sewerage line B of FIGURE 1, for example, by means of compressed air, then the local receptacle or tank is preferably provided with a readily removable cover 18, as shown in FIGURES 3 and 5. On this cover there may be mounted, firstly, a relatively small compressor 19 for creating the positive pressure required for the discharge, and, secondly, a valve device 2h for interrupting communication between the conduit V leading from the vacuum source VK shown in FIGURE 1 and the interior of the receptacle LB when said receptacle is to be emptied. The valve device 26 may be operated by a float 21 adapted, when the tank is almost filled, to urge a valve cone against a corresponding valve seat. In addition, the float may preferably be provided with an arm 22 adapted to actuate a switch 22 and thereby to start the motor driving the compressor 19, thus providing for automatic discharge of the local receptacle as soon as the vacuum pipe V is closed off from the local receptacle LB by the float 21.

In the arrangement shown in FIGURE 6, the compressor is assumed to be disposed remotely from the local receptacle or tank LB Numeral 23 indicates the compressed-air inlet pipe which is coupled, for example, to the air compression line TL of FIGURE 1. As the float 21 positioned in the receptacle or tank LB rises, a ballshaped valve member 24 coupled thereto by a flexible wire 24 that passes over pulleys 24" will leave its seat against the mouth of a pipe 23' and fall downwardly into a portion 23", whereupon the compressed-air is freely admitted into the interior of the tank LB via the pipes 23 and 23 after the vacuum pipe V is closed off. The arrangement may suitably be supplemented by an electromagnetic valve operating device 25 coupled to the member 24- and float 21 which enables the local tank to be discharged before the level therein 'has risen to the height at which the float becomes effective, if this should be desired.

In the arrangement illustrated in FIGURE 7, the ballshaped valve member 24- is aflixed to a wire 24 which is passed through a larger ball 26 and over pulleys 24" thence to a spring 27 associated with a pivoting tube 27. A V-shaped passage formed in the ball 26 serves to facilitate release of the ball from its valve seat against the mouth of the pipe 23. Numerals 27 and 28 indicate a pivotally mounted tube and a ball therein, respectively, associated with the float mechanism 21 (not shown) and the valve members 24- and 26. The ball 28 is adapted, when the tube 27 passes a dead centre position during its pivotal movement, to move rapidly to the opposite end of the tube thereby quickly unseating the valve member 24 and dropping the member 24, together with the ball 26, downwardly into the portion 23", whereby compressed air from the pipe 23 is admitted into the receptacle LE via the pipe 23' following the closing of the vacuum pipe V.

In all the arrangements shown in FIGURES 5 through 7, a substantial lowering of the sewerage level in LB is required to reopen the vacuum source valve and shut off the compressor 19 or close ofi the pipes 23, because the vacuum valve in the pipe V when closed is subjected to a lifting force created by the vacuum in the pipe, this force having to be overcome by the effective weight of the float 21 to open the valve again.

The waste water of the sewerage system should be transported as far as possible by the utilization of natural slope. Where the conduit BDT (FIG. 1) passes a hill or any similar irregularity in the area, the siphon principle can sometimes be utilized to convey the water over the hill, the conduit BDT being suitably provided in this case with a device such as is shown in FIGURES 8 and 9, which is connected in series relationship with the conduit BDT, as shown in FIG. 1 in the area A for example. This device essentially comprises a container 29 into which waste water and similar comparatively clean water is admitted via the conduit BDT at the base of a hill. Disposed within the container is a valve member 30 formed as a float and co-operating with a valve seat 31 of a waste water outlet conduit 32 which passes over the hill. When the water level within the container has fallen to a predetermined value, the float valve 30 will engage the seat 31. However, owing to the fact that the conduit 32 is now filled with water, the float valve 30* will not re-open until, due to the continued water inflow into the container 2%, the water level therein has reached a slightly higher level. In this way, the water level within the container 29 will alternate between two different values.

When the portion of the conduit acting as a siphon is to be filled initially, the float valve member 30 is forced by two jack-like devices 33 against its seat 31, after which water from a domestic water service main is admitted into the conduit 32 by opening a valve 34 in a pipe 35 passing through the entire float valve 30. The float 30 is free to slide within guide members 30' upwardly and downwardly by the pipe 35. For this pur-- pose, i.e., to fill the conduit 32 with water, the outlet end of conduit 32 must be kept closed, which may be effected in any suitable manner. FIGURES 10 and 11 show a valve '36 which is disposed at the topmost point of the conduit section concerned, i.e., at the top of the has fallen to a predetermined lower value.

hill, and which may be, for example, a conventional nonreturn valve. The purpose of the valve 36 is to vent such air as is displaced through the conduit 32 when filling the latter with water. To prevent air from entering the siphon conduit 32 through its discharge end, said conduit may suitably be provided at the outlet end with a water trap, as shown in FIGURE 12. Once the conduit 32 passing over the hill is filled with water, it acts as a siphon, and the jack-like devices 33- are unscrewed to permit the float 36} to operate, and the valve 34 in the pipe 35 is closed.

To prevent the waste water from freezing to ice in winter-time during its transport through the main conduits from the local collecting receptacles LB to the natural receiver, steps may be taken to secure as continuous a flow as possible through said conduits. With said object in view the local collecting receptacles LB should be dimensioned large enough to enable them to serve as flow equalizing receptacles. During day-time when the inflow of waste water to the collecting receptacles is a maximum, each receptacle will receive more waste water than the amount discharged causing the water level in the receptacle to rise, whereas during night-time when the receptacle receives only comparatively small amounts of waste water the amount of water accumulated during the previous day will be discharged. A suitable throttling of the outlet will ensure that the receptacle is never emptied entirely. On the other hand, arrangements should be made to prevent the receptacle from ever becoming quite full. The receptacle may, for example, be provided with a valve-controlled extra outlet, the outlet valve of which is controlled by a float which opens the valve when the water level in the receptable has reached a permissible maximum and closes the valve again when the water level The same result can be attained, of course, by providing the regular outlet with an adjustable throttle valve controlled by a float or the like, or in any other suitable manner.

The conduits E connecting the local receptacles LB mutually and with the main receptacle HB must be buried in the ground in a manner to secure that during wintertime the excrement sludge will never freeze to ice during its transport through the conduits and clog the same. Normally such a freezing is avoided by placing the conduits E in the ground at a frost-free depth. In such cases when the conduits E for transporting the excrement waste and the conduits BDT for transporting warm waste water run alongside one another, the conduits may be placed in the ground at a smaller depth, particularly if the two kinds of conduits are provided with a common heat insulation against the surroundings. A suitable manner of placing conduits in the ground is shown in FIGURE 13.

In said figures the reference symbol 38 denotes a transport conduit for excrement waste, 39 a transport conduit for waste water, 40 an ordinary fresh water conduit or pipe, and 41 and 42 vacuum and compressed-air conduits. All conduits 3$42 are enwrapped within a heat insulating mat 43, for example of mineral wool. The insulated group of conduits rests on a gravel bed 44 containing drain pipes 45. Disposed above the conduits is a semi-circular protective cover 46 formed of concrete. Owing to the emission of heat from the transport conduit 39 for waste water the temperature inside the insulating mat 43 is always higher than the temperature in the surrounding ground. Not only the conduit 38 but also the water pipe 40 may therefore be placed in the ground at a lesser depth below the ground surface than would otherwise be possible. The fresh water pipe 40 may advantageously be provided with a heat insulation of its own which prevents the water in the pipe from assuming too high a temperature in summertime.

In FIGURE 14 a conduit 38 for excrement sewerage and a conduit 39 for waste water as well as an air conduit 41 are disposed within a pre-existing larger diameter 7 sewerage conduit 47 which, for example, may be used for the for transport of drained-off surface water.

FIGURE 15 shows a cross-section through an open ditch which is utilized as a receiver and purifier for waste water. On the bottom of the ditch there is placed a compressed air conduit 48 which is provided along its entire length with narrow outlet-openings 49, as shown in FIG- URE 16, through which air is continuously or periodically discharged in order to produce a movement of the Water in the ditch while simultaneously increasing the oxygen content of the water, whereby the biological purification of the water in the ditch is accelerated. The compressed air could be heated during the cold season in order to maintain' asufiiciently high temperature of the water in the ditch to prevent interruption of the biological purifying process. If desired, the compressed air may contain chemical additions which promote the biological action. In addition to waste water from the sewerage system, drained-off surface Water can be disposed into the ditch via conduits 50 and 51. The open ditch is covered by a coarse net 52 adapted to prevent children and animals from falling into the ditch. In winter-time said net may serve as a supporting base for a heat-insulating covering adapted to prevent an excessive cooling-down of the water in theditch so that the water will never freeze.

The conduit'loop 53 shown in FIGURE 17, which may be provided at suitable points along the conduits through which iwaste transport is effected thnough suction, forms a kind of pocket in which the sewerage is collected so as to form a plug'which entirely fills out the cross-sectional area of the conduit. The plug is moved by the suction a considerable distance along the conduit in an integral condition, whereby the transport is facilitated.

All or certain of the conduits included in the sewerage system may advantageously be formed of plastic.

It will be appreciated that the volume of each evacuated local receptacle for excrement Waste and the capacity of the vacuum pump or other vacuum source must be selected with respect to the number of water closet bowls and other sanitary apparatus connected to the receptacle in question. In general, it is suitable to give a local receptacle a rather large volume, so that the inflow of air into the receptacle upon the simultaneous opening of a reasonable number of outlet valves allotted to sanitary apparatus shall not unduly reduce the vacuum in the receptacle. In cases when a local receptacle is connected to the main receptacle through a large-diameter conduit sloping continuously towards the main receptacle, the volume of the large-diameter discharge pipe will increase the effective pressure-equalizing capacity of the local receptacle, so that a local receptacle of smaller volume than otherwise can be used. Furthermore, a separate air conduit between the main receptacle, in which the vacuum is assumed to be generated, and the local receptacle can be dispensed with, in that the Waste discharge pipe will provide for the necessary air communication.

What I claim is:

1. A sewerage system for handling waste products, comprising a main receptacle for collecting waste products, a local receptacle under vacuum for collecting waste products, a first conduit connecting said receptacles together, a second conduit connecting said local receptacle to a source of waste products, a pressure-sensitive means connected between said local receptacle and said second 8; conduit for substantially decoupling said second conduit and said local receptacle when said second conduit undergoes -a substantial increase in pressure for at least a predetermined time, and pressure means connected to one of said receptacles for transporting said waste products from said local receptacle to said main receptacle.

2. A sewerage system according to claim 1, wherein said pressure means provides a pressure diiference between said local receptacle and said main receptacle.

3. A sewerage system according to claim 1 wherein said pressure means comprises a compressor having an outlet connected to said local receptacle for discharging air therein, a source of vacuum, conduit means containing a valve therein coupling said source of vacuum to said local receptacle, means disposed in said local receptacle adapted to close said valve when the quantity of waste products in said local receptacle rises to a predetermined level, and means disposed in said outlet for coupling air from said compressor to the interior of said local receptacle only when said valve is closed.

4. A sewerage system as set forth in claim 1 wherein said pressuresensitive means includes a cylinder, said cylinder communicating with said second conduit, movable means in said cylinder controlled by pressure in said second conduit for actuating a valve mechanism in the input to said local receptacle to close said input when the pressure in said second conduit exceeds a predetermined value for at least a predetermined time, said valve mechanism including a passage to bleed the pressure in said second conduit into said local receptacle.

5. A sewerage system as set forth in claim 1 wherein one of said conduits has a loop therein for forming a plug of waste therein to facilitate the movement of waste to said main receptacle.

6. A sewerage system for handling waste products, comprising a local receptacle under vacuum, a conduit connecting said local receptacle to a source of waste products, pressure-sensitive means connected between said local receptacle and said conduit for substantially decoupling said conduit and said local receptacle when said conduit undergoes a substantial increase in pressure for at least a predetermined time, and means for receiving waste products from said local receptacle.

7. A sewerage system for handling waste products, comprising a receptacle under vacuum for collecting waste products, a plurality of conduits each connecting said receptacle to a source of waste products, a check valve provided at the end of each conduit connecting with the receptacle, and means connected to each one of said conduits for substantially decoupling a conduit from said receptacle when said conduit undergoes a substantial increase in pressure for at least a predetermined time.

References Cited in the file of this patent UNITED STATES PATENTS 382,188 Pitt May 1, 1888 1,303,358 Montgomery May 13, 1919 1,587,864 Sargent June 8, 1926 2,300,039 Yedmans et al Oct. 27, 1942 2,400,651 Marsh May 21, 1946 2,822,329 Griflith Feb. 4, 1958 2,884,131 Mocarski Apr. 29, 1959

Claims (1)

1. A SEWERAGE SYSTEM FOR HANDLING WASTE PRODUCTS, COMPRISING A MAIN RECEPTACLE FOR COLLECTING WASTE PRODUCTS, A LOCAL RECEPTACLE UNDER VACUUM FOR COLLECTING WASTE PRODUCTS, A FIRST CONDUIT CONNECTING SAID RECEPTACLES TOGETHER, A SECOND CONDUIT CONNECTING SAID LOCAL RECEPTACLE TO A SOURCE OF WASTE PRODUCTS, A PRESSURE-SENSITIVE MEANS CONNECTED BETWEEN SAID LOCAL RECEPTACLE AND SAID SECOND CONDUIT FOR SUBSTANTIALLY DECOUPLING SAID SECOND CONDUIT AND SAID LOCAL RECEPTACLE WHEN SAID SECOND CONDUIT UNDERGOES A SUBSTANTIAL INCREASE IN PRESSURE FOR AT LEAST A PREDETERMINED TIME, AND PRESSURE MEANS CONNECTED TO ONE OF SAID RECEPTACLES FOR TRANSPORTING SAID WASTE PRODUCTS FROM SAID LOCAL RECEPTACLE TO SAID MAIN RECEPTACLE.

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