JP2012067443A - Scum suppressing device and scum suppressing method for manhole pump place - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress formation of oily scum inside a water tank of a manhole pump place over a long period of time at a low cost.SOLUTION: The scum suppressing device 36 includes a solid oily scum dispersant 38 comprising a surfactant and a storage container 40 for storing the oily scum dispersant, is installed inside the water tank 12 of the manhole pump place 10, and suppresses the formation of the oily scum on a sewage surface. A slit 54 is provided on a bottom part 40A of the storage container 40, it is installed at such a position that the bottom part 40A is immersed in sewage at a pump activation water level HW, and thus, the oily scum dispersant 38 is immersed in the sewage at the pump activation water level HW.

Description

  The present invention relates to a scum suppressing device and a scum suppressing method applied to a manhole pump station provided in the middle of a sewer route.

  Conventionally, in a sewer, a manhole pump station may be provided for relaying along the route. The manhole pump station, for example, temporarily stores sewage flowing in from an upstream pipe (inflow pipe) in a water tank at a place where sewage cannot flow due to the difference in elevation, and the amount of water (pump activation water level) ) Is a facility that drives a submersible pump installed in the water tank to pump water and send sewage to a downstream pipe by detecting that the water level has been reached.

  The submersible pump stops operation when the amount of sewage in the water tank decreases and reaches a predetermined pump stop water level. Therefore, a part of the sewage stays in the water tank in the manhole pumping station, and there is a problem that oily scum is likely to be generated on the sewage surface. Oil-based scum is a floating substance whose main component is oil and fat, also called oil balls and white solids. If oil-based scum is generated, it may cause malfunction by adhering to a water level gauge, etc. The scum adheres to an unsanitary state, and the cleaning work for removing the scum becomes complicated.

  Various proposals have been made to suppress the formation of such scum (see Patent Documents 1 and 2 below). For example, in Patent Document 1 described below, a stirrer is provided in a water tank of a manhole pump station, and scum components are mixed in a suspended state in water by stirring sewage to suppress scum formation. However, the provision of a stirring device leads to an increase in the equipment cost of the manhole pumping station, and it is practically difficult to add a stirring device to an existing manhole pumping station.

  On the other hand, it is known to use a surfactant as a dispersant for dispersing oily scum (see Patent Documents 3 and 4 below).

JP 2003-034978 A JP 2002-115313 A JP 2003-211189 A Japanese Patent Laid-Open No. 2003-211191

  When applying the dispersant for oily scum as described above to a manhole pump station, a method of injecting into the water tank every predetermined time while controlling the injection amount of the dispersant can be considered, but such an injection device should be provided. Will increase the equipment cost of the manhole pumping station. On the other hand, if the solid dispersant is put into the water tank as it is, the dissolution in the sewage is quick and the scum formation inhibitory effect cannot be sustained for a long time. Therefore, it is necessary for the maintenance person to frequently change the dispersant, and the maintenance cost increases.

  The present invention has been made in view of the above, and an object of the present invention is to provide a scum suppressing device and a scum suppressing method capable of suppressing the formation of oily scum in a water tank of a manhole pump station at a low cost over a long period of time. .

  A scum suppressing device for a manhole pumping station according to the present invention is a device that is installed in a water tank of a manhole pumping station and suppresses the formation of oily scum on the sewage surface in the water tank, and comprises a solid agent made of a surfactant. An oil-based scum dispersant having a shape and a storage container for storing the oil-based scum dispersant, provided with a hole through which water can flow at the bottom, and installed at a position where the bottom is immersed in sewage at a pump activation water level And a storage container for storing the oil-based scum dispersant so that the oil-based scum dispersant is immersed in sewage at the pump starting water level.

  The manhole pump station scum suppressing method according to the present invention is a method for suppressing the formation of oily scum on the sewage surface in the water tank of the manhole pump station, and is provided with a hole through which water can flow at the bottom. A solid oily scum dispersant made of a surfactant is stored in a container, and the bottom of the container is immersed in sewage at the pump starting water level so that the oily scum dispersing agent is immersed in sewage at the pump starting water level. It is characterized by being installed at a position.

  According to the present invention, a solid oily scum dispersant is used as an agent for suppressing the formation of oily scum, and the oily scum dispersant is installed in the water tank so as to be immersed in sewage at the pump starting water level. Therefore, the oil-based scum dispersant is not always immersed in sewage, but is immersed in sewage near the highest water level, and a part of the dispersant located on the bottom side of the storage container is immersed in sewage. The excessive dissolution of the oily scum dispersant can be prevented, and the dispersant component can be gradually eluted. Therefore, formation of oily scum in the water tank can be suppressed at a low cost over a long period of time.

It is a longitudinal cross-sectional view of the manhole pump station which concerns on embodiment. It is a plane sectional view of the manhole pumping station. It is a principal part expanded sectional view of this manhole pumping station. It is a disassembled front view of the scum processing apparatus of this manhole pump station. It is a bottom view of this scum processing apparatus. It is a principal part expanded sectional view in the middle of use of this scum processing apparatus. It is a principal part expanded sectional view of the scum suppression apparatus which concerns on the example of a change.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the manhole pump station 10 concerning embodiment forms the submersible pump 14 for pumping up sewage in the water tank 12 as a manhole main body embed | buried under the ground. Reference numeral 11 denotes a manhole cover.

  The water tank 12 is a tank that stores sewage flowing in from an inflow pipe 16 that is a sewage pipe on the upstream side, and the inflow pipe 16 is connected to a side wall at a central portion in the height direction. In the water tank 12, an inflow baffle 18 made of a metal plate that prevents scattering of sewage flowing in from the inflow pipe 16 is provided so as to cover the inlet 16 </ b> A from the inflow pipe 16.

  As shown in FIGS. 1 and 2, the inflow baffle 18 is attached to the wall surface of the water tank 12, and the inflow path 20 extending in the vertical direction along the wall surface of the water tank 12 is between the main water storage portion 12 </ b> A of the water tank 12. The partition is formed with. The lower end of the inflow baffle 18 extends below the lowest sewage water level, that is, below the pump stop water level LW.

  Two submersible pumps 14 are installed at the bottom of the water tank 12, and are configured to be appropriately switched. A discharge pipe 22 is connected to the discharge side of the submersible pump 14, and each discharge pipe 22 is connected to a pressure feed pipe 28 via a check valve 24 and a water stop valve (ball valve) 26, and externally (ie, , Downstream pipe line).

  Reference numeral 30 denotes a guide member made of a metal pipe for raising and lowering the submersible pump 14, and only the upper part thereof is shown in FIG.

  In the water tank 12, a water level gauge 32 for detecting the water level of sewage is provided. The water level gauge 32 is not particularly limited as long as it can detect the water level of the sewage stored in the water tank 12, for example, a pressure type water level gauge that detects the water level based on the water pressure, or a bubble type water level gauge. A float-type water level gauge can also be used. Reference numeral 34 denotes a backup float switch.

  The submersible pump 14, the water level gauge 32, and the float switch 32 are connected to a control unit (not shown) and are controlled as follows.

  Waste water (sewage) from a general household or the like is stored in the water tank 12 of the manhole pump station 10 through the inflow pipe 16. When the water level of the sewage in the water tank 12 rises and reaches a preset pump activation water level HW, the water level gauge 32 detects this and activates the submersible pump 14 by a control unit (not shown). Thereby, the sewage in the water tank 12 is pumped up and drained to the outside through the pressure feeding pipe 28. When the water level in the water tank 12 is gradually lowered by this drainage and reaches a preset pump stop water level LW, the water level gauge 32 detects this, and the operation of the submersible pump 14 is stopped by the control unit. By repeating such an operation, the manhole pumping station 10 is configured to intermittently send sewage flowing from the upstream pipeline to the downstream pipeline. In general, the submersible pump 14 is operated about once every 10 to 20 minutes, depending on the volume of the water tank 12, the installation position of the manhole pump station 10, and the time zone.

  Here, the pump start water level HW is set at a position lower than the height of the inlet 16A of the inflow pipe 16, and the pump stop water level LW is a level that can maintain the state where the suction port of the submersible pump 14 is immersed in sewage. Is set.

  In the manhole pump station 10 as described above, in order to suppress the formation of oily scum on the sewage surface in the water tank 12, the scum suppressing device 36 described below is installed in the water tank 12 in this embodiment.

  As shown in FIGS. 3 to 5, the scum suppressing device 36 includes a solid oil-based scum dispersant 38 made of a surfactant and a storage container 40 that stores the oil-based scum dispersant 38.

  Although the shape of the oil-based scum dispersant 38 is not particularly limited, in the present embodiment, it is formed in a columnar shape, more specifically in a columnar shape as shown in FIGS.

  The surfactant constituting the oily scum dispersant 38 is not particularly limited as long as the oily scum component can be dispersed to reduce or suppress the generation and growth of solid oily scum. Examples of the surfactant include fatty acid esters of polyhydric alcohols such as sorbitan fatty acid esters and sucrose fatty acid esters, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, monostearic acid polyoxyethylene sorbitan esters, and polyoxyethylene. Nonionic surfactants such as polyoxyethylene fatty acid esters such as oleic acid esters, polyoxyethylene castor oil and polyoxyethyleneoxypropylene glycol can be used, and for example, carboxylic acid-based anionic properties such as soap Surfactants and sulfonic acid anionic surfactants such as linear alkylbenzene sulfonic acid (LAS) can also be used. The oil-based scum dispersant 38 may contain other components such as an alkali agent and a shape-retaining agent together with the surfactant, as long as the oil-based scum dispersant 38 is a solid (lumb) containing the surfactant as a main component.

  The storage container 40 has a cylindrical shape as shown in FIGS. 3 to 5 and is a resin member capable of storing the oil-based scum dispersant 38 therein. Specifically, it includes a cylindrical main body 42, a lower side cap 44 that closes the lower end opening of the cylindrical main body 42, and an upper side cap 46 that closes the upper end opening of the cylindrical main body 42. The lower side cap 44 is fixed to the cylindrical main body 42, while the upper side cap 46 is detachably provided so that the oil-based scum dispersant 38 can be set in the storage container 40.

  An eyebolt 48 having a ring at the head is attached to the ceiling surface of the upper cap 46 in order to suspend the storage container 40 in the water tank 12. Further, a pair of engagement pins 50 project inwardly at two locations facing the radial direction on the inner peripheral surface of the upper cap 46.

  On the other hand, the upper end opening of the cylindrical main body 42 is provided with engagement grooves 52 that engage with the engagement pins 50 at two locations facing each other in the radial direction. The engaging groove 52 includes a first groove 52A extending downward from the upper end of the cylindrical main body 42, a second groove 52B extending in the circumferential direction from the lower end of the first groove 52A, and a second extending upward from the tip of the second groove 52B. It has a substantially J-shape consisting of three groove portions 52C, and is formed symmetrically with respect to each other at two locations facing each other in the radial direction.

  When the upper cap 44 is attached to the cylindrical main body 42, the upper cap 44 is put on the cylindrical main body 42 so that the engaging pin 50 is guided from the first groove 52A to the third groove 52C through the second groove 52B. Just twist a little.

  The bottom 40A of the storage container 40 is provided with a through hole 54 through which water can flow. In this example, as shown in FIGS. 4 and 5, the storage container 40 has a center support portion 56 that supports the lower surface of the oil-based scum dispersant 38 at the center portion of the bottom surface 40 </ b> B, A plurality of slits 54 extending radially from the bottom surface 40 </ b> B to the lower end portion of the side surface 40 </ b> C of the storage container 40 are provided around the central support portion 56. Specifically, as shown in FIG. 5, eight slits 54 are provided radially at equal intervals on the bottom surface of the lower cap 44 except for the central portion (central support portion 56). A similar slit is provided at the lower end of the side surface of the cylindrical main body 42 which is formed so as to rise on the side surface of the side cap 44.

  As shown in FIG. 1, the scum suppressing device 36 is installed at a position where the bottom 40A of the storage container 40 is immersed in sewage at the pump activation water level HW, whereby the oil-based scum dispersing agent 38 inside the pump is activated. The water level HW is soaked in sewage. That is, the storage container 40 is not soaked in sewage at normal water levels including the pump stop water level LW, and is installed so that the bottom 40A is soaked in sewage when approaching the pump activation water level HW that is the highest water level.

  Specifically, as shown in FIG. 3, the storage container 40 is suspended in the water tank 12 by the wire 58 by attaching a wire 58 as a suspension member to the eyebolt 48 of the ceiling portion.

  In the present embodiment, as shown in FIGS. 2 and 3, the storage container 40 is installed close to the surface 18 </ b> A on the opposite side of the inflow baffle 18 from the inflow path 20. That is, the storage container 40 is disposed close to the side surface 18 </ b> A of the inflow baffle 18 on the side opposite to the inflow path 20 across the inflow baffle 18. Therefore, the storage container 40 is suspended by projecting a locking tool 60 on the side surface 18 </ b> A of the inflow baffle 18 and hooking the upper end of the wire 58 on the locking tool 60.

  In the scum suppressing device 36 configured as described above, the oil-based scum dispersant 38 is not normally immersed in sewage, but is immersed in sewage when the water level rises and approaches the pump activation water level HW, and reaches the pump activation water level HW. When the submersible pump 14 is activated and drained, it is suspended in the air higher than the water surface.

  When the oily scum dispersant 38 is immersed in the sewage near the pump start water level HW, the surfactant is eluted into the sewage, so that the oily scum can be dispersed. At this time, the oil-based scum dispersant 38 is immersed in only the sewage surface, that is, in the vicinity of the water surface. However, since the oil-based scum is formed on the sewage surface, the sewage flows in the water tank 12 in the vertical direction. Even if there is almost no, generation | occurrence | production and growth of oil-based scum can be reduced.

  In the scum suppressing device 36, only the bottom 40A of the storage container 40 is immersed in the sewage at the pump starting water level HW, so that only the lower part of the oily scum dispersant 38 is also immersed in the sewage. In this way, the oil-based scum dispersant 38 is not always immersed in sewage, but is immersed in sewage near the highest water level, and even when immersed, the entire scum dispersant 38 is not partially immersed, but is partially immersed. Since it dissolves sequentially from the side, excessive dissolution of the oily scum dispersant 38 can be prevented and the surfactant can be gradually eluted.

  Thereby, for example, the oil-based scum dispersant 38 can be left in the storage container 40 for a long period of one month. That is, when the oil-based scum dispersant 38 is not dissolved, the upper cap 46 of the storage container 40 is opened and a new oil-based scum dispersant 38 is replenished. According to this embodiment, the oil-based scum dispersant 38 is replenished. Maintenance performance can be improved by reducing the number of replenishment operations of the dispersant 38. In addition, with such a simple device configuration, the formation of oil-based scum can be suppressed, so it is possible to take measures against scum at low cost for existing manhole pump stations as well as newly laid manhole pump stations. it can.

  Further, the storage container 40 includes a slit 54 extending radially around the center portion of the bottom surface 40B as a central support portion 56, and the slit 54 extends to the side surface 40C of the storage container 40. It is possible to avoid the problem that the scum dispersing agent 38 that swells and has a viscosity by closing the slit 54 blocks the slit 54. That is, as a hole provided in the bottom part of the storage container 40, a through hole can be provided only in the bottom surface 40B, but in this case, the through hole may be blocked by the swollen scum dispersant 38. On the other hand, the clogging caused by the swollen scum dispersant 38 can be eliminated by providing the slit 54 extending to the side surface 40C.

  Further, in the case of the radial slit 54 of the present embodiment, as water enters from the slit portion of the side surface 40C, the lower part of the scum dispersant 38 melts in a tapered shape as shown in FIG. The front end (lower end) of the head is supported by the center support portion 56. Therefore, sewage can enter and exit through the slit 54 more easily, and the effect of suppressing the formation of oily scum can be enhanced.

  Further, in the scum suppressing device 36 of the present embodiment, the upper side cap 46 is provided as a lid member that closes the upper end opening of the storage container 40, so even if water falls from the upper manhole cover 11 portion, It is possible to prevent the internal scum dispersant 38 from being splashed with water. If water is applied to the scum dispersant 38 from above, the scum dispersant 38 may stick to the wall surface of the storage container 40 and may not fall to the bottom surface 40B. However, by providing the upper cap 46, Trouble can be solved.

  Moreover, since the storage container 40 is installed along the back of the inflow baffle 18 in the case of the scum suppressing device 36 of the present embodiment, the following operational effects are exhibited. As shown in FIG. 3, the sewage flowing in from the inlet 16 </ b> A of the inflow pipe 16 is guided downward through the inflow path 20 as indicated by an arrow W, and the direction is changed at the bottom of the water tank 12 to change the inflow baffle. It flows upward along 18. Therefore, in a state where the bottom 40A of the storage container 40 is immersed in sewage, entry of sewage from the slit 54 is promoted, and the effect of suppressing the formation of oily scum can be enhanced.

  In the above embodiment, as shown in FIG. 3, the height of the slit 54 in the side surface 40C of the storage container 40 is set lower than the pump activation water level HW. However, as shown in FIG. The height of 54 may be set higher than the pump activation water level HW. As described above, by setting the height of the slit 54 higher than the maximum water level, when oily scum enters the storage container 40, the discharge performance can be improved.

  The shapes of the storage container 40 and the oil-based scum dispersant 38, the arrangement / shape of the slits 54 and the like in the above embodiment are merely preferred examples, and are not limited thereto. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Manhole pumping station 12 ... Water tank 16 ... Inflow pipe 18 ... Inflow baffle 20 ... Inflow path 36 ... Scum suppression device 38 ... Oil-based scum dispersing agent 40 ... Storage container 54 ... Slit 56 ... Center support part HW ... Pump starting water level

Claims (4)

A scum suppressing device that is installed in a water tank of a manhole pump station and suppresses the formation of oily scum on the sewage surface in the water tank,
A solid oily scum dispersant comprising a surfactant;
A storage container for storing the oil-based scum dispersant, comprising a hole through which water can flow at the bottom, and installed at a position where the bottom is immersed in sewage at a pump activation water level, so that the oil-based scum dispersant is A storage container for storing the oil-based scum dispersant to be immersed in sewage at a pump activation water level;
A scum suppressing device for a manhole pump station characterized by comprising:   The storage container has a center support part that supports the oil-based scum dispersant at the center part of the bottom surface, and serves as the flowable hole from the bottom surface around the center support part to the lower end of the side surface of the storage container. The scum suppressing device for a manhole pump station according to claim 1, further comprising a plurality of radially extending slits.   The manhole pump station includes an inflow baffle that prevents the sewage flowing from the inflow pipe from scattering and forms an inflow path along the wall surface of the aquarium, and the storage container is opposite to the inflow path of the inflow baffle. The scum suppressing device for a manhole pump station according to claim 1 or 2, wherein the scum suppressing device is installed close to the surface. A scum suppression method that suppresses the formation of oily scum on the sewage surface in a water tank of a manhole pump station,
A storage container having a hole through which water can flow at the bottom stores a solid oily scum dispersant made of a surfactant, and the storage container is immersed in sewage at the pump activation water level. Is installed at a position where the bottom is immersed in sewage at the pump activation water level.

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