TWI551752B - A liquid trap system - Google Patents

Description

Liquid trap system

The present invention is directed to a liquid trap system that is designed to allow liquid to pass through the liquid trap system in a downstream direction while preventing gas from passing through the liquid trap system in an upstream direction.

The following documents can be considered as background art: French Patent No. FR 2 923 503, US Patent No. 4 026 317, European Patent No. EP 2 033 557, European Patent No. EP 0 494 060, and World Patent No. WO 87/00880.

The present invention relates to a liquid trap system designed to allow liquid to pass through the liquid trap system in a downstream direction while preventing gas from passing through the liquid trap system in an upstream direction, wherein the liquid trap system includes at least a first And a second liquid trap.

The liquid trap system can include two or more liquid traps, such as two, such as three, such as four, and the like. The preparation of two or more liquid traps allows, for example, for different uses of the individual liquid traps such that the first drain line is connected to the first liquid trap and the second drain line is connected to the second liquid trap while The third liquid trap is configured to function as a floor drain, that is, a fixture that is placed into a floor, and is used to drain water from the surface of the floor and drain into a sewer system.

Furthermore, the preparation of a plurality of different liquid traps allows for a more compact design of the entire liquid trap system since the overall height of the system can be reduced. This is particularly the case when a buoyancy member is configured/used to close the liquid trap, as described in further detail below.

In one embodiment, at least two of the liquid traps, such as all, are provided in the same housing. Furthermore, at least two of the liquid traps, such as all, may be provided in series or in parallel. In the case of the present invention, the liquid wells are supplied in series when the liquid flowing out of the first liquid trap can be discharged only by flowing through another liquid trap. In the case of the present invention, when the liquid passing through the first liquid trap will not pass through the second liquid trap, the liquid traps are provided in parallel to discharge the liquid trap system.

In one embodiment, the liquid trap system, for example, forms part of a floor drain such that the upper surface of the liquid trap system is designed to be positioned at the same level as the floor, wherein the liquid trap system is Provided in this level. A screen for collecting larger particles, such as hair, may be provided on the upper surface of the floor drain. The liquid trap system can be used in connection with a drainage system in a kitchen, such as a private or industrial kitchen; in a laboratory, such as a research or testing laboratory of a pharmaceutical company; in a clinic, such as medical Or in a dental clinic.

In one embodiment, the first liquid trap is adapted to allow liquid to pass therethrough when the flow rate of the liquid flowing into the entire liquid trap system is higher than the first predetermined flow rate. Still further, in this particular embodiment, when the flow rate of the liquid flowing in the liquid trap system is higher than the second predetermined flow rate, the second liquid trap can be designed to allow liquid to pass therethrough. In this particular embodiment, the second predetermined flow rate can be greater than the first predetermined flow rate.

By providing a two-liquid trap designed to open at different flow rates, the flow rate through the individual liquid traps can be maintained at a higher flow rate. It is conceivable that the low flow rate increases the risk of precipitation and deposition of particles and grease.

In one embodiment, the flow rate at which the second liquid trap is opened is 20% higher than the flow rate at which the first liquid trap is opened, such as 30% higher, such as 40% higher. High, such as 50% higher, such as 75 percent higher, such as 100 percent higher.

As an example, the first liquid trap can be designed to be opened at the lowest possible flow rate, for example at a flow rate of less than 0.01 liters per second, while the second liquid trap remains closed unless the flow rate More than 0.4 liters per second. The result is that any liquid flowing into the liquid trap system is directed through the first liquid trap when the flow rate is below 0.4 liters per second. It should be understood that if the two liquid traps are simultaneously opened, the flow rate in each of the two liquid traps will be lower (i.e., if the capacity of the two liquid traps is identical, 50% is lower), The total amount of water will be separated between the liquid traps.

In this example, when the flow rate exceeds 0.4 liters per second, the liquid traps will both open, and thus the flow rate in each of the two liquid traps will be reduced. However, if the dynamic flow of liquid through the second liquid trap cannot maintain the second liquid trap in its open state, the second liquid trap will close again.

In the above example, it is assumed that the capacity of the two liquid traps is identical, that is, for the two liquid traps, and the maximum flow rates in the two liquid traps are the same. As described below, the system is designed such that when the second liquid trap is opened, the flow rate in the first liquid trap is maintained at its maximum, whereby the flow of liquid in the second liquid trap will A flow rate begins that is less than 50% of the flow rate of all liquid flowing into the entire liquid trap system.

It will be appreciated that in systems comprising more than two liquid traps, such as three liquid traps, each of the different liquid traps can be designed to allow passage of liquid at different flow rates of liquid flowing into the entire liquid trap system.

In one embodiment, if the flow rate of the liquid flowing into the entire liquid trap system is below a predetermined threshold, the liquid passes through the first liquid trap while being prevented from passing through the second liquid trap. In the same specific embodiment, if the flow rate is above the predetermined threshold, the liquid passes through the two liquid traps such that the first portion of the liquid passes through the first liquid trap while the second portion of the liquid Pass the second liquid trap.

In a specific embodiment, the first and/or the second liquid trap includes a locking system having a locking member, the locking member being designed to move between a locked position and an open position, wherein the locking In the position, the locking member prevents flow of liquid in the upstream direction, and in the open position, the locking member allows liquid to flow in the downstream direction. Moreover, when a predetermined amount of liquid is provided above the locking member, the locking member can be configured to bias into the locking manner such that the locking member is forced away from the locking position (eg, by gravity) position. In a specific embodiment, the locking system is below the buoyancy system described, and the locking member is a corresponding buoyancy member, alternatively, or as a supplement, the locking system is below the described elastic system And the locking member is its corresponding blocking member.

In one embodiment, at least one of the first and second liquid traps includes a buoyancy system, each of the buoyancy systems defining a recessed portion having an inlet and an outlet, and a buoyancy member is provided a recessed portion such that when a predetermined amount of liquid is received in the recessed portion, the entrance of the recessed portion is closed by the buoyancy member due to buoyancy of the buoyancy member, and when a predetermined amount The liquid is provided above the buoyancy member such that the buoyant member is forced out of the inlet by gravity.

One advantage of providing a buoyancy member is to improve the system capabilities to prevent backflow of liquid in an upstream direction. The reason for this is that the increased pressure causes the seal between the inlet and the buoyancy member to be improved as the two are forced toward each other with a greater force. The effect of the improved seal is that the liquid trap system can be capable of withstanding a pressure corresponding to 5 meters, such as 8 meters, such as 10 meters, such as 12 meters, such as 15 meters, such as 20 A meter, such as a 30-meter water column.

By providing a liquid trap that prevents backflow of liquid, such as by a buoyancy member, it can be ensured that liquid flowing out of one of the liquid traps does not flow upstream into the other of the liquid traps. If the other liquid trap is fluidly connected to a general purpose appliance (provided upstream of the liquid trap), it is particularly conceivable that the appliance will be damaged by this reflow of liquid.

By providing a liquid trap system with improved ability to withstand high pressure downstream of the liquid traps, the odor, viruses and bacteria are prevented from flowing backwards into the system. Furthermore, the dangerous gas in a sewer system is prevented from overflowing into the room, kitchen, bathroom, clinic, etc., through the liquid trap system as it flows back through the liquid trap system. Accordingly, the present invention reduces the risk of terrorist attacks by gases passing through the sewer system.

In one embodiment, the inlet is defined by an annular rim defining a circular opening.

It should be understood that in order to achieve this sealing effect, the inner diameter of the opening must be smaller than the outer diameter of the buoyancy member. If the diameter of the inlet is greater than the diameter of the buoyancy member, the liquid can flow through the inlet, for example if the downstream pressure increases. The annular rim may comprise an elastomeric material such as natural or synthetic rubber.

Alternatively, or as a supplement, at least one of the first and second liquid traps includes an elastic system, each of the elastic systems defining a recessed portion having an inlet and an outlet, and a blocking member is It is configured to be biased into contact with the inlet by an elastic member to close the inlet. In this particular embodiment, the blocking member can be forced out of the inlet by gravity when a predetermined amount of liquid is provided over the blocking member.

As in the case of the buoyancy member, the blocking member will improve the ability of the liquid trap system to increase the pressure downstream of the liquid trap system causing the blocking member and the inlet to be subjected to an even greater force. When forced toward each other, the backflow of the liquid in the upstream direction is resisted/prevented.

It will be appreciated that as the buoyancy of the buoyancy members is used to determine the flow rate at which the liquid trap opens, the spring constant of the resilient member determines the flow rate at which the liquid trap opens.

In one embodiment, each of the first and second liquid traps includes an elastic system. In this embodiment, the spring constant of the elastic member of the second liquid trap is greater than the spring constant of the elastic member of the first liquid trap. Accordingly, the first and second liquid traps are opened at different flow rates.

It should be understood that the principles of the buoyancy member and the resilient member can be combined in any manner. For example, one of the liquid traps can include a buoyancy member while the other of the liquid traps (in the same system) includes an elastic member. Furthermore, each of the liquid traps can include both a buoyancy member and an elastic member. In one embodiment, each of the first and second liquid traps includes a buoyancy system. In this system, the buoyancy of the buoyancy member of the first liquid trap may be lower than the buoyancy of the buoyancy member of the second liquid trap.

It will be appreciated that when the liquid trap system includes two buoyancy members having different buoyancy, the liquid trap provided with the buoyancy member having the lowest buoyancy will open before the other liquid trap (where the buoyancy member has a larger buoyancy system) . The difference in buoyancy can be achieved by providing different volumes of buoyancy members, for example the volume of the first buoyancy member can be smaller than the volume of the second buoyancy member.

Alternatively, the two buoyancy members may have exactly the same volume while the weights of the two buoyancy members are not identical. The difference in the weight of the two buoyancy members can be achieved by providing the two elements in different materials or by inserting a small weight in one of the buoyancy members, the weight being a liquid having a density, The density of the liquid is higher than the density of the liquid passing through the liquid trap system. Alternatively, the weight can be a metallic material.

In one embodiment, the first and second liquid traps are configured such that liquid flowing into the liquid trap system initially enters the first liquid trap, and if the flow rate is above a predetermined flow rate, the liquid A first portion flows through the first liquid trap while a second portion of the liquid flows into the second liquid well and further flows therethrough.

Furthermore, the effect is that the flow rate of the liquid flowing through the individual liquid traps is higher than if the two liquid traps were simultaneously opened. One of the advantages of this increased flow rate is that the precipitation and deposition of the material can be reduced or even eliminated.

The liquid trap system can be designed such that the individual liquid trap can be used not only to drain a floor but also to connect a drain to it. Accordingly, in one embodiment, the inlet of at least one of the first and second liquid traps is designed to be fluidly connected to an outlet of a drain. The drain can be a sink, a bathtub, a dishwasher, a washing machine or any other drain that must be connected to a drain.

It should be understood that the liquid trap system can take any form. As an example, the liquid trap system can, for example, form part of a drain tube such that it has the function of connecting two drain tubes.

In one embodiment, the buoyancy member defines an outer surface that is designed to prevent or reduce deposition of waste. It will be appreciated that the risk of blockage of the liquid trap system is reduced or even eliminated when deposition of material is prevented.

In a specific embodiment, the outer surface of the buoyancy member defines a plurality of indentations. The effect of the indentations is in use, and when the liquid flows through the liquid trap, the indentations will cause the buoyancy member to rotate. This rotation will cause particles or grease deposited on the outer surface of the ball to be removed, as the annular edge defining the opening of the liquid trap will scrape the material. The preparation of the dimples/small pits in the buoyancy member causes the boundary layer of water to be delayed by the separation of the balls. This effect is that the liquid tends to "attach" to the buoyancy member 112 and thus reduces the risk of other materials depositing on the surface of the buoyancy member.

In one embodiment, the buoyant member is coated on its outer surface with a material that prevents the deposition of waste material on its outer surface. An example of such a material is polytetrafluoroethylene (PTFE), such as Teflon.

It will be appreciated that any surface of the liquid trap system can be coated with the material (e.g., PTFE) to prevent deposition of material on either surface of its surface.

Figure 1 discloses a liquid trap system 100 in the form of a floor drain. However, as previously described, the liquid trap system can take any other form, such as the liquid trap system can form part of a waste water pipe. The liquid trap system 100 defines a first liquid well 102' and a second liquid well 102". Both liquid wells 102', 102" are provided below the upper surface 104 of the liquid trap system 100, the liquid trap system 100 being designed Thus, when the liquid trap system 100 is installed in the floor, the upper surface 104 is at the same level as the upper surface of the floor (not visible in the drawing). The upper surface 104 surrounds the main inlet 101 of the liquid trap system 100. Again, the system 100 defines a primary exit 103.

The liquid traps are fastened relative to the liquid trap system 100 by a snap ring 107 that is permanently or detachably fastened to the liquid trap system 100. In the particular embodiment in which the retaining ring 107 is detachably attachable to the liquid trap system 100, the detachable attachment can be achieved by a threaded or snap-locked connector. It will be appreciated that the ability to withstand back pressure (water backflow) is determined in part by this (permanently or detachably) fastening of the fastening ring 107.

Each of the liquid wells 102', 102" defines a recessed portion 106', 106" having an inlet 108', 108" and an outlet 110', 110". In each of the recessed portions 106, a buoyancy member 112', 112" is provided, which - when a liquid (e.g., waste water) is provided in the liquid traps 102', 102" - is forced with an annular edge 114', 114" cause contact. Each annular edge 114', 114" defines a channel having an inner diameter. The inner diameter of the passage is smaller than the diameter of the individual buoyancy members 112', 112", and thus the buoyancy of the buoyancy members 112', 112" causes the buoyancy member 112 to be forced with the annular edges 114', 114" Contact is made to close the individual liquid traps 102', 102".

The recessed portions 106', 106" form a portion of the water trap 102', 102" whereby water (or any other liquid) entering the recessed portion 106', 106" is received in the recessed portion 106', 106", the gas is prevented from passing through the inside of the liquid well 102', 102" in an upstream direction. Thus, the odor and bacteria located downstream of the liquid well 102', 102" are prevented from passing through the liquid. Wells 102', 102".

When water enters the recessed portions 106', 106", the water will flow over the edges 116', 116" of the outlet 110 defining the individual recessed portions 106', 106". The liquid trap effect is by the wall 118', 118" is achieved locally, the wall prevents the gases from passing in the upstream direction while allowing the liquid to pass in the downstream direction and partially through the buoyant members 112', 112".

It will be appreciated that the upright position of the edges 116', 116" determines the upright position of the upper surface of the liquid contained in the recessed portions 106', 106" (indicated by the dashed line 117). Thus, the relative positions of the annular edges 114', 114" and the edges 116', 116" determine how the buoyant members 112', 112" can approach the upper surface of the liquid. In other words, the aforementioned relative positions The minimum distance at which the buoyancy members 112', 112" are submerged below the water level is determined, and the force exerted on the annular edges 114', 114" by the buoyancy members 112', 112" is thus determined. Since this force determines the ability to be used in such water traps to prevent backflow, i.e., the flow of water in an upstream direction, it may be desirable in some embodiments to have the annular edge 114', 114" is positioned as far as possible away from the edge 116', 116" while still allowing the buoyant member 112', 112" to move during downstream flow of water in the system. However, it is also understood by the buoyancy member 112. The greater the force exerted by the ', 112' on the annular rim 114', 114", the more liquid must be provided above the buoyancy member 112', 112" for forcing the buoyancy member downward, such that The liquid trap opens and allows water to flow in this downstream direction.

In a particular embodiment of the invention, the difference is at least 3 mm, such as at least 5 mm, such as at least 10 mm, such as at least 15 mm, such as at least 20 mm, in a particular embodiment of the invention, the difference is Optionally, such water traps prevent backflow of water, even if the water pressure downstream of the liquid traps in the liquid system is at least 0.5 bar, such as at least 1 bar, such as at least 1.5 bar, such as at least 2 bar, such as at least 2.5 bar, such as at least 3.0 bar, such as at least 3.5 bar or 4 bar.

The wall surface 118', 118" terminates in a lower surface 120', 120" that is covered with a liquid when liquid is provided in the recessed portion. It should be understood that the wall surface 118' The distance from the lower surface 120', 120" of the 118" to the upper surface (the water/liquid level) of the liquid contained in the recessed portion (not shown) is also relevant to the liquid trap system 100. The determinant of the pressure experienced in this downstream direction while still preventing the flow of odors and bacteria in this upstream direction.

Figure 2 illustrates the use of the liquid trap system 100. In order to simplify the drawings, many of the reference numerals presented in FIG. 1 have not been indicated. However, since the two drawings are identical (except for the arrows indicating the flow), the reference numerals of Fig. 1 are also applied to Fig. 1.

As shown in FIG. 2, the first and second liquid wells 102', 102" are disposed relative to each other such that liquid flowing into the liquid trap system 100 will initially flow into the concave portion of the first liquid well 102'. 106' (indicated by arrow 121). This will cause the liquid to be collected in the inlet region 122' of the first recessed portion 106'. When the weight of the liquid exceeds a predetermined threshold, the liquid will cause The buoyancy member 112' is forced downwardly and thus no longer engages the annular edge 114'. This will cause the first liquid well 102' to open, whereby the liquid will flow through the first liquid well 102'. If the water flow exceeds the flow volume of the first liquid well 102, the liquid contained in the first inlet region 122' will flow above the separation wall surface 124, and the separation wall surface 124 separates the first liquid well 102'. An inlet region 122' and a second inlet region 122" of the second liquid well 102". This overflow of liquid is indicated by arrow 126. Similar to the first liquid well 102', when the second inlet region The second liquid well 102" will open when the weight of the liquid contained in 122" exceeds a predetermined threshold. In this state, only the liquid will flow through the first fluid well 102 ', and also the second fluid through the well 102. "

One advantage of providing two liquid wells 102', 102" is that the overall height of the system can be smaller than conventional systems (having the same capabilities to withstand the high pressure downstream of the liquid traps).

FIG. 3 illustrates a state with increased pressure (indicated by arrow 125) in a region downstream of the liquid trap system 100. However, the preparation of the buoyancy members 112 causes the liquid trap system 100 to cause the members 112 to abut against the annular edge 114 due to the buoyancy of the buoyancy member 112 such that backflow of the water is prevented. The buoyancy of the buoyancy member 112 is indicated by arrow 127.

In Figures 4-6, a drain tube 128 has been coupled to the second liquid trap 102" by a rubber manifold 130, which is designed in a particular embodiment of the drawings such that it defines a wide portion 132 and a narrow portion 134. The inner diameter of the wide portion corresponds to the outer diameter of the drain tube 128 such that the drain tube 128 can be inserted into the wide portion 132 whereby a seal is defined Between the drain pipe 128 and the rubber header 130. Similarly, the outer diameter of the narrow portion 134 corresponds to the inner diameter of the inlet region 122" of the second liquid well 102", thus allowing the rubber header 130 will be inserted into the inlet region 122" whereby a seal is defined between the rubber header 130 and the inlet region 122". Due to the seal, the first inlet region 122' to the second inlet The overflow of the water of the area 122" is prevented.

Since the drain tube 128 is directly connected to a liquid trap, bacteria located downstream of the liquid trap system 100 are prevented from passing through and into the drain tube 128 in the upstream direction.

The first liquid well 102' of the liquid trap system 100 of Figures 4-6 has the function of a floor drain, and thus the liquid (e.g., water) provided on the floor will flow into the first liquid well 102', such as by The arrow 121 indicates and continues to flow out of the main outlet 103 of the liquid trap system 100. This flow is indicated by arrow 125 in FIG. The buoyancy of the buoyancy member 112" prevents the inflowing water from entering the drain pipe 128 in an upstream direction. Thus, any general purpose appliance that is fluidly connected to the drain pipe 128 is prevented from flowing into the appliance from the drain pipe. The liquid is damaged.

FIG. 7 discloses yet another embodiment of the present invention in which the primary outlet is provided in the bottom of the liquid trap system 100.

Figure 8 discloses a buoyancy member 112 that defines an exterior surface that is designed to prevent or reduce the deposition of waste material due to the preparation of the dimples 136. In use, the indentations 136 will cause the buoyant member 112 to rotate relative to the annular edge 114 whereby any waste that has been deposited on the outer surface is scraped off by the annular edge 114.

100. . . Liquid trap system

101. . . main entrance

102', 102"... liquid trap

103. . . Main exit

104. . . Upper surface

106', 106"... concave part

107. . . Tight ring

108', 108"... entrance

110', 110"...export

112. . . Buoyancy member

112', 112"... buoyancy components

114. . . Annular edge

114', 114"... ring edge

116', 116"... edge

117. . . dotted line

118', 118"... wall

120', 120"... lower surface

121. . . arrow

122', 122"... entrance area

124. . . Separate wall

125. . . arrow

126. . . arrow

127. . . arrow

128. . . Drainage pipe

130. . . Collector

132. . . Broad part

134. . . Narrow part

136. . . dent

The invention will now be described in further detail with reference to the drawings in which:

Figure 1 discloses a liquid trap system in accordance with the present invention.

Figure 2 reveals the flow of water into the liquid trap system.

Figure 3 discloses the prevention of backflow in the liquid trap system.

Figure 4 discloses a drain tube connected to a liquid trap system in accordance with the present invention.

Figures 5-6 illustrate the use of the liquid trap system when a drain line is connected to the liquid trap system.

Figure 7 illustrates another alternative configuration of the outlet;

Figure 8 discloses a buoyancy member in accordance with an embodiment of the present invention.

100. . . Liquid trap system

101. . . main entrance

102', 102"... liquid trap

103. . . Main exit

104. . . Upper surface

106', 106"... concave part

107. . . Tight ring

108', 108"... entrance

110', 110"...export

112', 112"... buoyancy components

114', 114"... ring edge

116', 116"... edge

117. . . dotted line

118', 118"... wall

120', 120"... lower surface

122', 122"... entrance area

124. . . Separate wall

Claims (14)

A liquid trap system designed to allow liquid to pass through the liquid trap system in a downstream direction while preventing gas from passing through the liquid trap system in an upstream direction, wherein the liquid trap system includes at least one first and one a second liquid trap, the first liquid trap being designed to allow liquid to pass therethrough when a flow rate of liquid flowing into the entire liquid trap system is above a first predetermined flow rate, and wherein The flow rate of the liquid in the liquid trap system is above a second predetermined flow rate, the second liquid trap being designed to allow liquid to pass therethrough, the second predetermined flow rate being greater than the first predetermined flow rate. A liquid trap system according to claim 1, wherein the first and/or the second liquid trap comprises a locking system having a locking member, the locking member being designed to be adapted to be in a locked position and an open position. Intermoving, in the locked position, the locking member prevents flow of liquid in the upstream direction, and in the open position, the locking member allows liquid to flow in the downstream direction, and wherein the locking member is configured to The locking member is biased into the locked position, and wherein when a predetermined amount of liquid is provided above the locking member, the locking member is forced out of the locked position by gravity. The liquid trap system of claim 1, wherein at least one of the first and second liquid traps comprises a buoyancy system, each of the buoyancy systems defining a recessed portion having an inlet and an outlet, and a buoyancy member is provided in the recessed portion such that when a predetermined amount of liquid is received in the recessed portion, the entrance of the recessed portion is closed by the buoyancy member due to buoyancy of the buoyant member And when a predetermined amount of liquid is raised When placed above the buoyancy member, the buoyant member is forced to exit the inlet by gravity. The liquid trap system of claim 1, wherein at least one of the first and second liquid traps comprises an elastic system, each of the elastic systems defining a concave portion having an inlet and an outlet, and The blocking member is configured to be biased into contact with the inlet by an elastic member to close the inlet, and wherein when a predetermined amount of liquid is provided above the blocking member, the blocking member is by gravity Forced to leave the entrance. A liquid trap system according to claim 3, wherein each of the first and second liquid traps comprises one of a buoyancy system or an elastic system. The liquid trap system of claim 3, wherein each of the first and second liquid traps comprises a buoyancy system, and wherein the buoyancy member of the first liquid trap has a lower buoyancy than the second liquid trap The buoyancy of the buoyancy member. The liquid trap system of claim 6, wherein the volume of the first buoyancy member is smaller than the volume of the second buoyancy member. The liquid trap system of claim 4, wherein each of the first and second liquid traps comprises an elastic system, and wherein the elastic member of each of the first and second liquid traps has a spring constant, The spring constant of the elastic member of the second liquid trap is greater than the spring constant of the elastic member of the first liquid trap. The liquid trap system of claim 1, wherein the first and second liquid traps are configured such that liquid flowing into the liquid trap system initially enters the first liquid trap, and if the flow rate is at a predetermined time Flow rate The first portion of the liquid flows through the first liquid trap while the second portion of the liquid flows into the second liquid trap and further flows therethrough. A liquid trap system according to claim 1, wherein the inlet of at least one of the first and second liquid traps is designed to be fluidly connected to an outlet of a drain. A liquid trap system according to claim 3, wherein the buoyancy member defines an outer surface that is designed to prevent or reduce deposition of waste. A liquid trap system according to claim 11 wherein the outer surface of the buoyancy member defines a plurality of dimples. A liquid trap system according to claim 3, wherein the buoyant member is coated on its outer surface with a material that prevents deposition of waste on its outer surface. A liquid trap system according to claim 13 wherein the material comprises polytetrafluoroethylene (PTFE).