JP2008030021A - Sand pumping and transporting apparatus and sand pumping and transporting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sand pumping and transporting apparatus which can efficiently pumps and transport settled sand in a sand sedimentation pond with small power and with high head, over a long distance. <P>SOLUTION: The sand pumping and transporting apparatus is equipped with a solid liquid recovery tank 3, a suction transportation pipe 2 and a vacuum pump 4 for decompressing the inside of the solid liquid recovery tank 3 and the suction transportation pipe 2. Further the sand pumping and transporting apparatus is equipped with an air releasing pipe 7 which is connected with the suction transportation pipe 2 at an upper position than the highest water level HWL of the sand sedimentation pond 1, an air injection tube 12 which has an air injection valve 15 and which is connected with the suction transportation pipe 2 at a connection 12a that is below a connection 7a of the air releasing pipe 7, namely in water of the sand sedimentation pond 1, and a control section 20 which repeats opening/closing of the air injection valve 15 and an air releasing valve 6 so that a water column for transportation longer by about length between these connections is formed in the suction transportation pipe 2 to enable transportation to be carried out by injecting pressurized air from the air injection tube. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sand transporting apparatus and a sand transporting method for efficiently sucking and transporting a sedimentary solid together with a liquid, and in particular, deposited in a sand basin or septic tank sludge of a sewage treatment facility or a human waste processing facility. The present invention relates to a sand-carrying apparatus and a sand-carrying transport method for sand-carrying sand together with liquid by vacuum suction and transporting it to a solid-liquid recovery tank.

  The sand transportation facilities in sand basins such as sewage treatment facilities and human waste treatment facilities contain sediment, gravel, metal deposits, etc., and are in an environment that generates strong odors. Accordingly, it has been demanded to remove sand sediment automatically, without problems such as clogging, with a high lift, a long transport distance, energy saving, efficient and safe removal. For this reason, various methods have been proposed as techniques for sanding from a sand basin, transporting to a solid-liquid recovery tank, washing, and solid-liquid separation.

  Conventionally, in order to transport sand by sand transport, a method using a sand pump or a method of suctioning by vacuum has been mainly used. However, in the method using the sand pump, the blade may be damaged or rapidly worn by stone pieces, metal pieces, etc. mixed in the settling sand. In addition, conveyors are sometimes used for transporting sand settling, but maintenance problems such as odor leaking and sewage splashing cannot be maintained even if the conveyor is covered with a cover. was there.

  Further, there are various methods for suctioning by vacuum, and they have been improved. For example, an ejector method that generates a negative pressure by high-pressure water injection, or an air-jet mixed water stream in which high-pressure water is further mixed with air in the sand transport pipe, is jetted near the end opening of the suction transport pipe. Pressure and air lift effects are applied and suctioned (see, for example, Patent Documents 1 and 2), vacuum suction by a vacuum pump, and compressed air or air with a blower from an air introduction pipe connected in the vicinity of the end of the sand transport pipe There is a method of continuously injecting, sucking and transporting sand by sand (see, for example, Patent Documents 3 to 5). There is also a system in which air and / or pressurized water is introduced in the middle of the sand transport pipe (see, for example, Patent Document 6).

  In addition, the opening of the end of the sand transport pipe is devised, the inner cylinder (sand transport pipe) is wrapped in the outer cylinder, it has an outside air suction control valve, and sucks in a spiral from the suction port. An apparatus has also been proposed (see, for example, Patent Documents 7 and 8). Furthermore, the gap between the inner cylinder and the outer cylinder is increased to form a mixing chamber, an intake pipe is provided above the mixing chamber below the liquid level, and an open / close mechanism (valve) is provided on the liquid level of the intake pipe. It has also been proposed to intermittently perform vacuum suction by mixing the solid liquid and suction air of the sand basin into the mixing chamber by opening and closing (see, for example, Patent Document 9). According to this method, it is said that a large amount of earth and sand can be transported by reducing the apparent specific gravity of the solid content in the mixing chamber.

  In addition, as a liquid suction device, an intake pipe with a throttle valve is provided directly above the liquid surface, and suction is performed by a suction pump to form a number of stepped gas-liquid layers in the suction pumping pipe. There has also been proposed a method (see, for example, Patent Document 10). In addition, as a suction device for the high head of mud water, an air inlet pipe with a throttle valve is provided directly above the liquid level of the suction transport pipe and at the bent part, and the muddy water part and the air part are connected and formed in multiple stages in the suction transport pipe. There has also been proposed an apparatus that raises the head by the amount of the sum of the heights of the air sections by performing vacuum suction (see, for example, Patent Document 11).

  In addition, as a method of pumping the stored liquid at the bottom of structures such as underground tanks, the opening of the pumping pipe from the gas-liquid separation tank attached with the vacuum pump is set in the stored liquid, and the control valve is positioned above the stored liquid level. In a device with an attached (atmospheric) introduction pipe, the pumping process for closing the electromagnetic control valve and sucking liquid into the pumping pipe, and opening the electromagnetic control valve to allow air to flow from the introduction pipe, A method of repeatedly pumping up the liquid and intermittently pumping up the liquid has also been proposed (see, for example, Patent Document 12).

  Currently, the water ejector method that generates negative pressure using high-pressure water alone and the method that adds the air lift effect to the negative pressure by the mixed jet water flow that mixes air with high-pressure water are mainly used. is there. According to these methods, the transportation route can be freely bent as compared to a conveyor and the like, space saving can be achieved, no odor is produced, and maintenance can be saved. It is said that.

  However, since these devices that are practically used suck up sedimentation and water by negative pressure by a high-pressure water ejector, a high-pressure water pump with a large power (55 to 75 kW) is required, and energy consumption increases. Since a large amount of water is required in a short time, a large storage tank is required. In addition, as high-pressure water, low turbidity, for example, secondary treatment water of sewage or water quality equivalent to tap water is required, and securing this becomes a problem. Furthermore, since the amount of water sucked up together with the settling sand is large, a large-scale separation device for separating the settling sand and the water at the transportation destination is required. For this reason, there is a problem that the entire apparatus is not compact, and there is a large problem to be solved that energy consumption is large. As described above, conventional devices have become unsuitable for the needs of the times in terms of global warming and energy saving.

JP 52-111008 A Japanese Utility Model Publication No.59-119305 JP-A-60-216813 Japanese Patent Laid-Open No. 02-035902 Japanese Patent Application Laid-Open No. 07-031807 Japanese Patent Laid-Open No. 08-038811 Japanese Utility Model Publication No. 62-144504 JP 63-253200 A Japanese Patent Application Laid-Open No. 07-103199 Japanese Utility Model Publication No.41-004361 Japanese Patent Laid-Open No. 55-064200 JP-A-11-193800

  The present invention has been made in view of such problems of the prior art, and is capable of efficiently transporting sand in a sand basin with a small amount of power, with a high head, and over a long distance. And to provide a method of transporting sand.

  According to one aspect of the present invention, there is provided a sand transporting device that can lift sand by small power. This sand transporting device includes a solid-liquid recovery tank and a suction transport pipe. The suction transport pipe has a first end that is submerged in the water in the sand basin and a second end that is connected to the solid-liquid recovery tank. The sand-carrying transport device includes a decompression device that decompresses the solid-liquid recovery tank and the suction transport pipe, and an open air pipe connected to the suction transport pipe at a position above the highest water level of the sand basin, An atmosphere release valve is provided for opening the connection portion of the suction transport pipe with the atmosphere release pipe through the atmosphere release pipe. In addition, the sand transporting device closes the air release valve and sucks the sediment deposited in the sand basin as a solid-liquid mixture with water into the suction transport tube, and the water level is from the connection with the air release tube. When the air rises upward, the air release valve is opened to form a transport water column above the connecting portion, and the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank The transport water column is transported to the solid-liquid recovery tank by the above, the air release valve is closed immediately before the entire transport water column enters the solid-liquid recovery tank, and the air release valve is repeatedly opened and closed to repeat the transport. A control unit that repeats the formation and transportation of the water column is provided.

  The degree of vacuum used in the present specification is represented by minus display with the atmospheric pressure set to 0 kPa and the negative pressure as it is. For example, −49.0 kPa (−5 mAq) means that the atmospheric pressure is set to 0 kPa and the pressure is lowered by 49.0 kPa. Further, a high vacuum means that the negative pressure is large, and a low vacuum means that the negative pressure is small.

  According to such a configuration, when the water containing sedimentation is sucked into the suction transport pipe by the decompression device and the air release valve is opened when the water level of the suction transport pipe rises above the connection portion of the air release pipe. The connection portion of the atmosphere release pipe is open to the atmosphere, and a transport water column can be formed above the connection portion. This transport water column is transported to the solid-liquid recovery tank by the difference between the atmospheric pressure acting on both ends and the degree of vacuum.

  In other words, the atmospheric pressure is sucked from the connecting portion at a stroke by the decompression device, and becomes atmospheric pressure. The transport water column is transported while sucking the air from the connection portion due to the difference between the degree of vacuum acting on the upper surface of the transport water column above the connection portion and the atmospheric pressure acting on the lower surface of the transport water column. To do. At this time, the transport water column is initially a solid-liquid mixture, but gradually changes from the rear of the transport water column to a gas-solid liquid mixture during transport. What is important in the present invention is that the atmosphere is sucked in a piston flow at once when the atmosphere release valve is opened. The slower the air suction, the more easily a large amount of air enters the formed water column for transportation as bubbles, and the degree of collapse of the shape of the water column increases. However, even if this shape collapses, the entire water-solid liquid column is finally transported by repeating the sand transporting process.

  And just before the whole water column for transport enters the solid-liquid recovery tank, the air release valve is closed, and the sediment deposited in the sedimentation basin is sucked into the suction transport pipe together with water as a solid-liquid mixture. The water level is raised above the connection portion of the atmosphere release pipe, and then the atmosphere release valve is opened to form a transport water column above the connection portion.

In the suction transport pipe, a transport water column is basically formed after the solid-liquid mixture is formed, and before the entire transport water column enters the solid-liquid recovery tank, that is, before it is transported. In addition, the suction is started so that the solid-liquid mixture is sucked from the sand basin and the next water column for transportation can be formed. As a result, air does not communicate between the solid-liquid recovery tank and the open air pipe, the vacuum level of the solid-liquid recovery tank does not change so much, and a certain range of vacuum always acts on the entire suction transport pipe. In addition, it is possible to stabilize the flow rate of sucking the solid-liquid mixture from the sand basin and the transport flow rate of the transport water column in the suction transport pipe.
When the air release valve is opened, the air sucked into the suction transport pipe enters the solid-liquid recovery tank by transport, but in order to keep the degree of vacuum of the solid-liquid recovery tank within a predetermined range, For example, the water-sealed vacuum pump is operated almost continuously, and the sucked air is discharged.

  For example, when the diameter of the suction transport pipe is 80 A (nominal diameter: for example, the inner diameter is 81.1 mm in Sch 20S of SUS304) and the initial value is −49.0 kPa (−5 mAq) as a practical degree of vacuum, The solid-liquid mixture could be sucked to a height of 2.0 to 2.5 m from the highest water level in the sand basin. And the height (length) of the water column for transport became an average of 2.3 m, and the sedimentation concentration at this time was 20 to 35%, and the average was 27%. Moreover, even if the sand transport was repeated, the fluctuation range of the degree of vacuum was within a predetermined value.

  As described above, according to the present invention, the power of the vacuum pump for maintaining the vacuum degree of the solid-liquid recovery tank after reaching the predetermined vacuum degree may be small power, and the solid-liquid recovery tank with small power. By repeating the operation of transporting the sand to the sand, the solid-liquid mixture containing the sand can be transported.

  According to another aspect of the present invention, there is provided a sand transporting device capable of pulling up sand sink more efficiently with small power. This sand transporting device includes a solid-liquid recovery tank and a suction transport pipe. The suction transport pipe has a first end that is submerged in the water in the sand basin and a second end that is connected to the solid-liquid recovery tank. The sand-carrying transport device includes a decompression device that decompresses the solid-liquid recovery tank and the suction transport pipe, and an open air pipe connected to the suction transport pipe at a position above the highest water level of the sand basin, An atmosphere release valve is provided for opening the connection portion of the suction transport pipe with the atmosphere release pipe through the atmosphere release pipe. The sand transporting device includes an air injection pipe connected to the suction transport pipe in the water of the sand basin, an air transfer device for sending air into the suction transport pipe, and the air transfer through the air injection pipe. The apparatus includes an air injection valve for injecting air into the suction transport pipe from a connection portion of the suction transport pipe with the air injection pipe. Furthermore, the sand transporting device sucks the sand deposited in the sand settling basin together with water as a solid-liquid mixture into the suction transport pipe by closing the air release valve and the air injection valve, and the water level of the sand settling basin is When the air injection valve is opened above the highest water level, the solid-liquid mixture above the connection with the air injection pipe is opened in the vicinity of or above the connection with the air release pipe. To open the atmosphere release valve and close the air injection valve to open the connection with the atmosphere release pipe to the atmosphere to form a water column for transportation above the connection with the atmosphere release pipe, The transport water column is transported to the solid-liquid recovery tank due to the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank, and the entire transport water column enters the solid-liquid recovery tank. Just above Closing the open valve, and a control unit to repeat the transportation with the formation of the transportation of water by repeating the opening and closing of the atmosphere release valve and the inflation valve.

  According to such a configuration, when the water containing sedimentation is sucked into the suction transport pipe as a solid-liquid mixture by the decompression device, and the water level rises above the connection with the air injection pipe, the air injection valve Pressurized air is injected by opening and the solid-liquid mixture can be pushed up by this pressurized air. Furthermore, by opening the atmosphere release valve and closing the air injection valve, a long water column for transportation is formed in the suction transportation pipe, and the lower surface of the transportation water column is raised near or above the connection part of the air release pipe. Can do. Then, due to the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank, the transport water column can be transported to the solid-liquid recovery tank.

  That is, the lower surface of the solid-liquid mixture sucked above the highest water level of the sand settling basin by the pressurized air from the connection portion of the air injection pipe is preferably set close to or above the connection portion of the air release pipe. Then, open the air release valve and close the air injection valve. Thereby, a comparatively long transportation water column is formed, and the transportation water column is transported to the solid-liquid recovery tank by the difference between the atmospheric pressure and the degree of vacuum acting on both ends of the transportation water column. Immediately before the entire transport water column enters the solid-liquid recovery tank, the atmosphere release valve is closed, the transport water column is formed again, and then the atmosphere release valve is opened to repeat the transportation. Of this transport water column, the portion pushed upward by the pressurized air is a portion corresponding to the length between the connection portion of the air release pipe and the connection portion of the air injection pipe, and is located below the transport water column. Equivalent to. For this reason, the sediment concentration in this part tends to be high due to the influence of gravity sedimentation of the sediment. Therefore, compared with the case where only the atmosphere open pipe is used, the transportation efficiency is improved because the formed water column for transportation can be made longer and the sediment concentration is higher.

  There is basically one transport water column in the suction transport pipe, and before the entire transport water column enters the solid-liquid recovery tank, that is, before transport, Control so that the suction of the solid-liquid mixture from the pond starts and the next water column for transportation can be formed. As a result, air does not communicate between the solid-liquid recovery tank and the open air pipe, the vacuum level of the solid-liquid recovery tank does not change so much, and a certain range of vacuum always acts on the entire suction transport pipe. In addition, it is possible to stabilize the flow rate of sucking the solid-liquid mixture from the sand basin and the transport flow rate of the transport water column in the suction transport pipe.

When the air injection valve and the air release valve are opened, pressurized or sucked air intermittently enters the solid-liquid recovery tank, but the pressure is reduced to maintain the vacuum level of the solid-liquid recovery tank within the specified range. For example, a water-sealed vacuum pump as an apparatus is operated almost continuously, and the air sucked into the solid-liquid recovery tank is discharged.
It is preferable to provide a vacuum sensor in the solid-liquid recovery tank, and select and operate a vacuum pump as a decompression device so that the vacuum of the solid-liquid recovery tank falls within a predetermined range.
In addition, the solid-liquid recovery tank is preferably provided with a ventilation valve that opens the degree of vacuum in order to wash the sucked sediment.

  For example, the suction transport pipe has a diameter of 80 A, an air injection pipe is connected below the liquid level 1 m below the connection part of the open air pipe, and the initial value is -49.0 kPa (-5 mAq) as a practical degree of vacuum. As a result, it was possible to suck the solid-liquid mixture to a height of 2.0 to 2.5 m and an average of 2.3 m from the highest water level HWL. Next, the air injection valve is opened to inject pressurized air, and the lower surface of the solid-liquid mixture above the connection part of the air injection pipe is pushed up near or above the connection part of the atmosphere release pipe to open the atmosphere release valve. In addition to the above-mentioned average height of 2.3 m, a long transport water column with an average of 3.3 m, which was increased by about 1 m, could be formed. The sediment concentration of this long water column for transportation was 20 to 35%, and the average was 30%. Moreover, even if the sand transport was repeated, there was almost no change in the degree of vacuum.

  Moreover, even if the sand transport was repeated, the fluctuation range of the degree of vacuum was within a predetermined value. The above-mentioned positive length of about 1 m corresponds to the length of the connecting portion of the underwater air injection pipe and the connecting portion of the open air pipe. On the other hand, when the pressurized air is not injected, the formed solid-liquid mixture, that is, the length of the water column for transportation is 2.3 m on average, and the sand concentration is 20 to 35%, average. 27%.

  Thus, according to the present invention, by appropriately setting the distance between the connection portion of the air injection pipe and the connection portion of the atmospheric release pipe, a long water column for transportation can be obtained as the height (distance). can get. Moreover, since the sedimentation concentration can be increased, it is possible to transport the sand efficiently. Also, once the vacuum level has been reached, the vacuum pump power to maintain the vacuum level of the solid / liquid recovery tank may be small, and the operation of transporting sand to the solid / liquid recovery tank with low power will be interrupted. By repeating the process repeatedly, the solid-liquid mixture containing the sedimentation can be transported.

  The first end portion of the suction transport pipe may have a shape in which the inner diameter is gradually reduced so as to have an inclination of 50 degrees to 70 degrees, and the minimum diameter of the opening portion of the suction transport pipe is It is preferable that the diameter is ½ or more and the minimum diameter is 40A or more. The suction flow rate at the opening with such minimum diameter is about 4 times the suction flow rate of the main suction pipe, and it is transferred to the solid-liquid recovery tank without clogging the sand that has been taken in the transport pipe. become able to. That is, a conventional bell mouth type having an opening shape can be used, but as described above, an opening shape having an inclination with respect to the horizontal plane is preferable so that the inner diameter gradually decreases toward the tip. This is because the suction flow velocity of the opening is larger than that of the bell mouth type.

  Moreover, it is preferable that the said sand transporting apparatus is further provided with the water injection nozzle which fluidizes the sedimentation sand of the vicinity of the 1st end part of the said suction transportation pipe | tube by jetting water. As a result, when a large amount of sand is accumulated in the suction portion of the suction transport pipe, it is possible to smoothly suck the sand into the suction transport pipe by fluidizing the sand sediment by the water jet nozzle. This water spray nozzle is placed in the sand settling basin so as to collect sand near the first end of the suction transport pipe. Designed.

  Moreover, the said sand transporting apparatus may further be provided with the suction transport valve provided above the connection part of the said air release pipe of the said suction transport pipe. By providing a plurality of suction transport pipes having suction transport valves for one solid-liquid recovery tank and a decompression device, it is possible to perform sanding by these suction suction transport pipes by controlling the suction transport valves. Become. Moreover, at the time of initial start-up, by opening the suction transport valve after fully depressurizing the inside of the solid-liquid recovery tank with the decompression device with the suction transport valve closed, the opening of the first end of the suction transport pipe A high degree of vacuum (suction force) can be applied, and sand with high viscosity and high specific gravity can be sucked up.

  Moreover, when there are a plurality of sand basins, it is possible to cope with a plurality of sand basins by controlling a suction transport valve provided in each suction transport pipe corresponding to each sand basin. On the other hand, when one sand basin and one suction transport pipe are provided, the present invention can be implemented without providing a suction transport valve. When the suction / transport valve is not provided, the degree of vacuum in the suction / transport pipe gradually increases when the degree of vacuum of the solid-liquid recovery tank is increased usually over 60 to 120 seconds. When the degree of vacuum in the suction transport pipe reaches a predetermined value, the solid-liquid mixture is sucked to a predetermined level in the suction transport pipe according to the degree of vacuum.

In a preferred aspect of the present invention, the air release pipe is connected to the suction transport pipe at an angle of 50 degrees to 70 degrees with respect to a horizontal plane, and the inner diameter of the air release pipe is equal to the diameter of the suction transport pipe. The opening area when the air release valve is fully open is approximately the same as the cross-sectional area of the air release pipe.
In a preferred aspect of the present invention, the air injection pipe is connected to the suction transport pipe at an angle of 50 degrees to 70 degrees with respect to a horizontal plane, and the opening area when the air injection valve is fully opened is The cross-sectional area of the air injection tube is substantially the same.
This is because air resistance by piping and valves is reduced as much as possible at the time of atmospheric suction and pressurized air injection, so that atmospheric suction and pressurized air injection are performed at once in a piston flow. This is to prevent the collapse of the shape of the water column for transportation due to mixing as much as possible and to carry out transportation efficiently.

In a preferred embodiment of the present invention, a vacuum degree sensor that detects the degree of vacuum in the suction transport pipe is provided at a position 3 to 15 m away from the second end of the suction transport pipe, and is detected by the vacuum degree sensor. A monitoring device for monitoring the degree of vacuum is further provided.
By detecting the degree of vacuum in the suction transport pipe, it is possible to grasp the operating state of the sand transporting device, that is, the transport state of the water column, and to reflect the detected change in the degree of vacuum in the control and effectively utilize it. The reason why the vacuum degree sensor is provided at a position of 3 to 15 m from the second end of the suction transport pipe is that the transport speed of the water column fluctuates in the range of 3 m / sec to 15 m / sec. This is because it is necessary to detect that the transport water column has passed before the entire transport water column has entered. The closer the installation position is to the solid-liquid recovery tank, the more the entire water column for transportation enters, and the risk of communication between the solid-liquid recovery tank and the open air pipe increases. If the solid-liquid recovery tank and the open air pipe communicate with each other, the degree of vacuum in the suction transport pipe and in the solid-liquid recovery tank will decrease. In order to avoid this danger, the vacuum degree sensor is preferably provided at a position 3 to 15 m from the second end of the suction transport pipe.

  According to another aspect of the present invention, there is provided a sand transporting method capable of lifting sand by small power. According to this method, the first end of the suction transport pipe is submerged in the water of the sand basin, and the second end of the suction transport pipe is connected to the solid-liquid recovery tank. An air release pipe is connected to the suction transport pipe at a position above the highest water level of the sand basin. The inside of the solid-liquid recovery tank and the suction transport pipe is depressurized. The air release valve provided in the air release pipe is closed, and the sand deposited in the sand basin is sucked into the suction transport pipe together with water as a solid-liquid mixture. When the water level rises above the connection part of the atmosphere release pipe, the atmosphere release valve is opened to open the connection part with the atmosphere release pipe to the atmosphere, and the water column for transportation is placed above the connection part. Form. Due to the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank, the transport water column is transported to the solid-liquid recovery tank while suctioning the atmosphere through the open air pipe. The air release valve is closed immediately before the entire water column for transportation enters the solid-liquid recovery tank. The formation and transportation of the water column for transportation are repeated by repeatedly opening and closing the air release valve.

  According to another aspect of the present invention, there is provided a sand transporting method capable of lifting sand by small power. According to this method, the first end of the suction transport pipe is submerged in the water of the sand basin, and the second end of the suction transport pipe is connected to the solid-liquid recovery tank. An air release pipe is connected to the suction transport pipe at a position above the highest water level of the sand basin. An air injection pipe is connected to the suction transport pipe in the water of the sand basin. The inside of the solid-liquid recovery tank and the suction transport pipe is depressurized. The air release valve provided in the air release pipe and the air injection valve provided in the air injection pipe are closed, and the sediment deposited in the sand basin is sucked into the suction transport pipe together with water as a solid-liquid mixture. When the water level rises above the water level of the sand basin, the air injection valve is opened to inject air from the air transfer device into the suction transport pipe and above the connection with the air injection pipe. Push the solid-liquid mixture upward. The air release valve is opened and the air injection valve is closed to open the connection portion with the atmosphere release pipe to the atmosphere to form a transport water column above the connection portion with the atmosphere release pipe. Due to the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank, the transport water column is transported to the solid-liquid recovery tank while suctioning the atmosphere through the open air pipe. The air release valve is closed immediately before the entire water column for transportation enters the solid-liquid recovery tank. The formation and transportation of the transport water column are repeated by repeatedly opening and closing the air release valve and the air injection valve.

  ADVANTAGE OF THE INVENTION According to this invention, the sand sink of a sand basin can be sand-transported for a long distance efficiently with a small power with a high head. In addition, since the main equipment of the sand transporting device can be made smaller and the degree of freedom of the arrangement of the suction transportation pipe can be increased, energy saving can be achieved compared to the conventional device, and the installation of the device can be reduced. The degree of freedom can be improved.

  Hereinafter, an embodiment of a sand transporting apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 15. 1 to 15, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic diagram showing the configuration of the sand transporting apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the sand transporting device includes a suction transport pipe 2 in which one end 2 a (opening) is submerged in water in a sand basin 1 and the other end 2 b of the suction transport pipe 2. The solid-liquid collection tank 3 and a vacuum pump (decompression device) 4 connected to the solid-liquid collection tank 3 are provided. A sedimentation discharge valve 5 for discharging the sediment collected in the solid-liquid collection tank 3 is provided below the solid-liquid collection tank 3.

  The solid-liquid recovery tank 3 is generally positioned above the sand basin 1 so that the sand transporting device can transport the sand accumulated in the sand basin 1 to the solid-liquid recovery tank 3 along with water. It has become. In addition, the sedimentation sediment deposited on the bottom of the sedimentation basin 1 includes earth and sand such as pebbles and sand residue in addition to the sand.

  An air release pipe 7 provided with an air release valve 6 is connected to the suction transport pipe 2. The air release pipe 7 is connected to the suction transport pipe 2 at a connection portion 7 a located slightly (100 to 500 mm) above the highest water level HWL of the sand basin 1. When the atmosphere release valve 6 attached to the atmosphere release pipe 7 is opened, the connection portion 7a of the suction transport pipe 2 with the atmosphere release pipe 7 is opened to the atmosphere. A controller 8 is connected to the atmosphere release valve 6, and the controller 8 controls the opening and closing of the atmosphere release valve 6.

  In addition, a large number of water injection nozzles 19 for injecting water are provided in the vicinity of the end portion 2 a of the suction transport pipe 2, and the sedimentation fluid is fluidized by the water injection from the water injection nozzle 19, and the suction transport pipe. Sand is collected in the vicinity of the end portion 2a. In addition, the structure of the bottom of the sand basin 1 is also inclined to facilitate sand collection.

  An operation in the case where the sedimentation sediment deposited on the bottom of the sedimentation basin 1 is pulled up using the sand transporting device having such a configuration will be described. FIG. 2 is a timing chart showing the operation of the pumping sand transport device showing the operation and stop of the vacuum pump 4 in FIG. 1, the opening / closing timing of the air release valve 6, the change in the degree of vacuum of the solid-liquid recovery tank 3, and the change in the water level. It is an example of a chart (process table).

  First, as shown in FIGS. 1 and 2, the vacuum pump 4 is driven with the atmosphere release valve 6 closed. Thereby, the inside of the solid-liquid recovery tank 3 and the suction transport pipe 2 to which the vacuum pump 4 is connected is depressurized in about 60 seconds to a predetermined degree of vacuum, for example, −58.8 kPa (−6 mAq), As shown in FIG. 3, the water containing the settling sand in the settling basin 1 is sucked into the suction transport pipe 2 as a solid-liquid mixture 9. At this time, if necessary, water is jetted from the water jet nozzle 19 to fluidize the sand and make it easy to suck the sand from the opening of the end 2a.

  The control unit 8 is preferably -44.1 kPa (-4.5 mAq) until the degree of vacuum of the solid-liquid recovery tank 3 is -19.6 kPa (-2 mAq) to -78.4 kPa (-8 mAq). Wait until it reaches 58.8 kPa (-6 mAq). In the example shown in FIG. 2, the initial degree of vacuum is set to −58.8 kPa (−6 mAq), and the degree of vacuum during steady operation (during the second and subsequent sand transport) is set to about −49.0 kPa (−5 mAq).

  The degree of vacuum of the solid-liquid recovery tank 3 is -44.1 kPa (-4.5 mAq) to 58.8 kPa (-6 mAq), and the water level of the solid-liquid mixture 9 in the suction transport pipe 2 is connected to the atmosphere open pipe 7. When rising above the part 7a, the air release valve 6 is opened to open the connection part 7a of the suction transport pipe 2 to the air release pipe 7 to the atmosphere. By opening the air release valve 6 in this way, as shown in FIG. 4, the solid-liquid mixture 9 in the suction transport pipe 2 located above the connection portion 7a of the air release pipe 7 is transported to the water column for transportation. 10 And this water column 10 for transport is a figure by the pressure difference of the vacuum degree which acts on the edge part by the side of the solid-liquid collection | recovery tank 3, and the atmospheric pressure which acts on the edge part by the side of open air, ie, the lower surface of the water column 10 for transportation. As shown by 5-1, 10-1 and 10-2, it moves toward the solid-liquid recovery tank 3 and is transported.

  When the controller 8 opens the atmosphere release valve 6, the water level of the solid-liquid mixture 9 in the suction transport pipe 2 needs to be above the connection part 7 a of the atmosphere release pipe 7. The control unit 8 normally controls the timing for opening and closing the atmosphere release valve 6 according to time. Further, the controller 8 transports the sand from the change in the degree of vacuum detected by the degree-of-vacuum sensor (not shown) of the solid-liquid recovery tank 3 or the degree-of-vacuum sensor 14 provided in the suction transport pipe 2 shown in FIG. It may be determined whether the process is normally performed, and the entire apparatus may be controlled. That is, an alarm may be issued and the operation may be stopped due to the detected abnormality in the degree of vacuum.

  The end of the sand transporting process is determined based on the high water level of the solid-liquid recovery tank 3, the low water level of the sand basin 1, the time-up of the set time, and the like. In the present embodiment, the transport flow rate in the suction transport pipe 2 of the water column for transport is 3 to 15 m / sec, and usually a high flow rate of 6 to 7 m / sec is obtained. The installation position of the vacuum sensor 14 (see FIG. 6) takes into account the high flow rate and the time of 0.5 to 1.0 seconds required for the air release valve 6 to be opened and closed, and the entire water column for transportation. Does not enter the solid-liquid recovery tank 3, the open-air pipe 7 and the solid-liquid recovery tank 3 communicate with each other, and the vacuum degree of the solid-liquid recovery tank 3 including the suction transport pipe 2 is not significantly reduced. As described above, on the suction transport pipe 2 which is 3 to 15 m, preferably 5 to 10 m away from the second end 2b so that the atmosphere release valve 6 can be opened and closed with a margin in response to the signal from the vacuum sensor 14. To do.

  Here, just before the entire transport water column 10 enters the solid-liquid recovery tank 3, that is, as shown in FIG. 5, the transport water column 10-2 is maintained so that the vacuum of the solid-liquid recovery tank 3 is maintained. The control unit 8 closes the air release valve 6 before the rear end of the gas enters the solid / liquid recovery tank 3, and there is no air communication path from the air release valve 6 to the solid / liquid recovery tank 3. It is preferable to do so. Thereby, since the inflow amount of air from the atmosphere release valve 6 can be minimized, the degree of vacuum in the solid-liquid recovery tank 3 can be increased and the fluctuation range can be kept small. For example, when the stationary vacuum is −49.0 kPa (−5 mAq), the fluctuation range is as small as −46.5 kPa (−4.75 mAq) to −51.4 kPa (−5.25 mAq).

  When the air release valve 6 is closed again, as shown in FIG. 3, the water containing the sand settling in the sand settling basin 1 is sucked into the suction transport pipe 2 as described above, and the solid-liquid mixture 9 is formed again. . Thereafter, by repeating the same process as described above, the sediment deposited on the bottom of the sedimentation basin 1 can be intermittently sand transported to the solid-liquid recovery tank 3.

  When releasing the atmosphere through the atmosphere release valve 6, it is important to allow a large amount of air to flow in in a short time with almost no loss. It is preferable to transport the sand efficiently by avoiding air from entering and mixing below the water column 10 for transportation. Further, as the transport water column 10 is transported through the suction transport pipe 2 as indicated by 10-1 and 10-2 in FIG. 5, the sedimentation and water separation and mixing of the sucked air proceed. The water column 10 for transportation collapses from the original shape. For this reason, in this embodiment, even if the transport water column 10 is in the state of 10-1 and 10-2 so that there is no air communication path in the suction transport pipe 2, the inner wall of the suction transport pipe 2 is always It is preferred to keep the sealed portion in place.

  Here, maintaining the state where the sealed portion is always maintained may maintain the state where at least a part of the suction transport pipe 2 is sealed by the transport water columns 10, 10-1, 10-2. In order to avoid the risk of being difficult to seal with the water columns 10, 10-1, 10-2 for transportation and to maintain more certainty, the air release valve 6 is changed from the open state to the closed state, and the solid-liquid mixture 9 The opening / closing timing of the atmosphere release valve 6 may be controlled by the control unit 8 so that the suction formation is started and the degree of vacuum of the solid-liquid recovery tank 3 acts on the entire inside of the suction transport pipe 2. Since the opening / closing timing varies depending on the state of sand settling in the sand basin 1, that is, the properties of the solid-liquid mixture 9, the transport distance, and the like, it is preferable to determine the optimum opening / closing timing, opening / closing time, etc. by trial operation.

  Therefore, the diameter of the suction transport pipe 2 is 50A to 125A, preferably 65A to 100A. If the diameter is smaller than 50A, the phenomenon that the sedimentation is likely to settle in the suction transport pipe 2, particularly the horizontal pipe section, and clog the pipe itself. Depending on the degree of vacuum of the solid-liquid recovery tank 3, the transport is possible. There is a risk that a situation will become impossible. Once this clogging occurs, it is difficult to eliminate even if the degree of vacuum is increased. On the other hand, if the aperture is larger than 125A, the following problem occurs. That is, when the atmosphere is released at the connection portion 7 a of the atmosphere release pipe 7, a transport water column made of a solid-liquid mixture is formed in the suction transport pipe 2. However, since the atmospheric pressure is below the transport water column, the sand sediment containing the liquid as the solid-liquid mixture is likely to fall from the lower surface of the transport water column. For this reason, the water column for transportation collapses from below, making it difficult to maintain its shape. Furthermore, the sedimentation and the liquid are easily separated in the horizontal pulling pipe portion, and finally it is difficult to always maintain the state where the above-described sealed portion is present in the sand transporting pipe. In addition, the larger the diameter, the larger the amount of the solid-liquid mixture to be sucked, which requires a vacuum pump performance that can reach the corresponding vacuum degree in a short time, which is not preferable in terms of energy saving.

  The air opening valve 6 has a diameter of 1/2 or more than the diameter of the suction transport pipe 2 and less than the diameter of the suction transport pipe 2 and can be opened and closed quickly for 1 second or less, preferably 0.5 seconds or less. An open valve is preferred. Moreover, it is preferable that the atmosphere release valve 6 is a valve that can be fully opened and fully closed, and the opening area when fully opened is approximately equal to the cross-sectional area of the atmosphere release pipe 7. Furthermore, it is also important that the atmosphere release pipe 7 is connected to the suction transport pipe 2 at a predetermined angle with respect to the horizontal plane, preferably 50 to 70 degrees. This is to prevent the solid matter in the suction transport pipe 2, that is, the sand sediment, from flowing back to the atmosphere release valve 6 and accumulating. Further, even if the sand is slightly inserted into the air release pipe 7, the above-mentioned connection angle is larger than the repose angle of the sand, so that the viscous sand is more easily sucked into the suction transport pipe 2 and does not remain. This is to prevent pressure loss from occurring in the air suction. Therefore, the connection angle may be larger than 70 degrees. However, it is not preferable to connect pipes having different diameters at a considerable angle from the viewpoint of manufacturing, and in practice, it is sufficient to set the angle to 70 degrees or less that is easy to connect.

  In the embodiment of the present invention, when the air release valve 6 is opened, the air is smoothly sucked into the connection portion 7a of the suction transport pipe 2 and the air release valve 7 at a stretch, and is higher than the vicinity of the connection portion 7a. It is necessary to suck the solid-liquid mixture in a piston flow by the action of the degree of vacuum of the solid-liquid recovery tank 3 so as to form a water column for transportation. This is because the more slowly the air is drawn into the piston flow at a stretch, the more easily the air enters the formed transport water column, and the more difficult it is to transport in the piston flow. This is because the collapse of the sand, that is, the separation of the sand and the liquid proceeds. On the other hand, the solid-liquid mixture part below the connecting portion 7a moves and falls toward the sand basin while the sand and liquid are separated.

  The time from the full open to the full close of the air release valve 6 is usually 2 to 10 seconds, and the time from the full close to the full open is 1 to 5 seconds. In the example shown in FIG. Set to time. Thus, since the time from the full open to the full close of the atmosphere release valve 6 and the time from the full close to the full open are short, the time required for the sudden opening and the sudden close of the atmosphere release valve 6 is better, A valve that can be opened and closed quickly must be selected, and the timing of opening and closing signal transmission must be determined according to the valve specifications.

  Moreover, it is preferable that the opening diameter of the end portion 2 a of the suction transport pipe 2 is ½ or more of the diameter of the suction transport pipe 2. This is because if the diameter is too small, it may be clogged with sedimentation, and if it is too large, the suction flow rate, that is, the suction force becomes too small. When the degree of vacuum of the solid-liquid recovery tank 3 is −49.0 kPa (−5 mAq) and the diameter of the suction transport pipe 2 is 80 A, the suction speed of the solid-liquid mixture 9 in the suction transport pipe 2 is normally 1.5-2. .5m / sec. Therefore, for example, if the diameter of the opening part of the end part 2a is 40A, which is 1/2, the opening area becomes 1/4, and the suction flow rate becomes about 4 times as large as 6 to 10 m / second. Pebbles and the like can also be sucked by such a high suction flow rate of the opening and will not be clogged.

  Moreover, as shown in FIG. 1, it is preferable that the suction conveyance pipe 2 has the horizontal piping parts 2c and 2d and the vertical piping part 2e. In particular, it is preferable that there are several stages of the horizontal piping portion 2c and the vertical piping portion 2e. And it is preferable to have a vertical piping part and a horizontal piping part alternately. The portion connected to the solid-liquid recovery tank 3 is preferably a vertical piping portion following a long horizontal piping portion. The length of the horizontal piping section is 3 to 15 m, preferably 5 to 10 m because the transport flow rate of the water column for transport is 3 to 15 m / sec, usually 6 to 7 m / sec. In the air release valve 6 and the air injection valve of the second embodiment to be described later, the time required for rapid opening and closing of the valve takes 0.5 seconds to 1.0 seconds, so that the entire transport water column is a solid-liquid recovery tank. 3 so that there is no seal portion in the suction transport pipe 2 and the atmosphere does not communicate with the solid-liquid recovery tank 3.

  In FIG. 1, the vertical piping portion 2e extends upward from the horizontal piping portion 2c, but may be configured to extend downward from the horizontal piping portion 2c. After the transport water column 10 passes, even if a part of the transport water column 10 containing sand remains on the pipe wall of the suction transport pipe 2, it falls in the vertical piping part 2e and remains in the horizontal piping part 2c. There is a case. However, the sand remaining in the horizontal pipe portion 2c is absorbed by the transport water column 10 passing at a high flow rate during the next sand transport, and transported to the solid-liquid recovery tank 3.

  In the embodiment of the present invention, it is important to positively provide the horizontal piping portion. Therefore, the suction transport pipe 2 including a plurality of stages of vertical pipe portions and horizontal pulling pipe portions is preferable. This is because even if the sedimentation of the transport water column that has entered the horizontal piping section sinks and remains at the bottom of the horizontal piping section, it is absorbed and transported to the next transport water column. Therefore, the length of the vertical piping portion from the sand basin 1 of the suction transport pipe 2 is set to a length that can accommodate the transport water column 10 shown in FIG. 4, and immediately from the bent portion 2f to the horizontal pulling pipe portion 2c. Good. It is not preferable to lengthen this vertical piping part more than necessary because the separation and sedimentation of the sand in the vertical piping part proceed. There is no problem as long as the length is within the transportable range, even if the laterally drawn piping portion 2c is lengthened positively and sand remains at the bottom of the piping. Compared with the case where the horizontal pipe portion is short, when the long horizontal pipe portion is used, the amount of sand that remains separated at the bottom of the horizontal pipe portion increases. However, the remaining sand sediment is sucked and transported at a high transport speed of the transport water column transported next. Therefore, by using the horizontal pulling pipe portion 2c having an appropriate length, the sedimentation can be transported efficiently. It is preferable that other horizontal piping parts also have an appropriate length.

  The bent portion 2f that connects the vertical piping portion and the horizontal piping portion of the suction transport pipe 2 is a smooth flow as a vent pipe having a gentle bend of radius (R) = 0.5 m to 1.5 m. It is also important. By using a bent pipe having such an appropriate bend, that is, an appropriate radius, the resistance during transportation can be made much smaller than that of a normal elbow or the like, and a smooth flow can be obtained.

  As described above, when the transport water column 10 is transported, the air release valve 6 is opened to suck the air. At this time, since the transport water column 10 is between the atmosphere and the solid-liquid recovery tank 3, the air does not directly flow into the solid-liquid recovery tank 3. However, since the transport water column 10 has a considerable kinetic energy before the solid-liquid recovery tank 3, all of it is transported into the solid-liquid recovery tank 3 before closing the air release valve 6. There is a fear. When air is communicated between the opened air release valve 6 and the solid-liquid recovery tank 3, air having good fluidity flows into the solid-liquid recovery tank 3 in a short time, and the vacuum Decrease the degree. As a means for avoiding this, only a control method using a timer may be employed. However, since the transport speed of the transport water column 10 varies depending on the concentration (specific gravity) of sand sediment or the length thereof, stable operation is possible. For this purpose, not only the vacuum sensor (not shown) of the solid-liquid recovery tank 3 itself, but also the vacuum sensor 14 is installed in the suction transport pipe 2 in front of the solid-liquid recovery tank 3 as shown in FIG. It is preferable to do this. In this case, it is confirmed by the vacuum degree sensor 14 that the transport water column 10 has passed through and has become the atmospheric pressure, and this is used as an auxiliary to the timer control for closing the atmosphere release valve 6. In FIG. 6, the vacuum sensor 14 is installed in the vertical piping part 2 e of the suction transport pipe 2 that is 10 m away from the second end 2 b with the solid-liquid recovery tank 3. Although it is easy to install the upper surface of the horizontal pipe portion 2d, this is not the case for the reason described above when priority is given to the distance from the second end portion 2b. As the vacuum sensor 14, a diaphragm type sensor can be used.

  The control unit 8 sets the opening time and closing time of the air release valve 6, the timing thereof, the valve opening / closing speed, confirmation of full opening / closing, control of the degree of vacuum of the solid-liquid recovery tank 3, etc. The necessary control functions may be simultaneously provided.

  FIG. 7 is a schematic diagram showing the configuration of the sand transporting apparatus according to the second embodiment of the present invention. Note that the configuration and operation of the second embodiment that are not particularly described are the same as those of the first embodiment described above, and redundant description thereof is omitted. In the present embodiment, an air injection pipe 12 connected to the suction transport pipe 2 is provided at a connection part 12a in the sand basin water below the connection part 7a to the atmosphere opening pipe 7. The length between the connection part 12a of the air injection pipe 12 and the connection part 7a of the atmosphere opening pipe 7 is preferably 0.5 to 2.0 m, and this length is applied to the design water level of the sand settling basin 1 or applied. It is appropriately changed depending on the degree of vacuum of the solid-liquid recovery tank 3 or the like.

  A compressor 16 as an air transfer device is connected to the air injection pipe 12 via a pressure reducing valve 13, and an air injection valve 15 is provided between the compressor 16 and the suction transport pipe 2. A control unit 20 is connected to the atmosphere release valve 6 and the air injection valve 15, and the opening and closing of the atmosphere release valve 6 and the air injection valve 15 is controlled by the control unit 20.

  In the present embodiment, a suction transport valve 18 is provided in the middle of the suction transport pipe 2. In the example of the first embodiment described above, since the suction transport valve 18 is not provided, if the initial vacuum degree of the solid-liquid recovery tank 3 is not increased to, for example, about −58.8 kPa (−6 mAq), A degree of vacuum of about −49.0 kPa (−5 mAq) required at the time of repetition cannot be obtained. This is because energy is consumed to suck the solid-liquid mixture or the like when the initial vacuum degree is formed. When the suction transport valve 18 is provided in the present embodiment or the first embodiment, the sand can be transported at a vacuum degree of about −49.0 kPa (−5 mAq) from the beginning. Thus, by providing the suction transport valve 18, the vacuum formation time (˜60 seconds) can be performed in advance, the time required for suction transport can be apparently reduced, and the initial vacuum degree can be reduced. Energy saving can be achieved as much as possible.

  An operation in the case where the sedimentation sediment deposited on the bottom of the sedimentation basin 1 is pulled up using the sand transporting device having such a configuration will be described. FIG. 8 is a timing chart (process table) showing the operation of the sand transporting apparatus of FIG. FIG. 9 is a timing chart (process table) showing an example of the opening / closing operation of the air injection valve 15 and the atmosphere release valve 6.

  First, as shown in FIGS. 7 to 9, the vacuum pump 4 is driven with the atmosphere release valve 6, the air injection valve 15, and the suction transport valve 18 closed. As a result, the solid-liquid recovery tank 3 to which the vacuum pump 4 is connected and the inside of the suction transport pipe 2 from the suction transport valve 18 to the solid-liquid recovery tank 3 are, for example, about −49.0 kPa (−5 mAq) for about 60 seconds. Reduce pressure with.

  The control unit 20 preferably has a vacuum degree of the solid-liquid recovery tank 3 in the range of −19.6 kPa (−2 mAq) to −78.4 kPa (−8 mAq) in order to correspond to the required lifting height of the sand transport, the transport distance, and the like. Can be controlled to -44.1 kPa (-4.5 mAq) to -58.8 kPa (-6 mAq). In the example shown in FIG. 8, the initial degree of vacuum is -49.0 kPa (-5 mAq), and the degree of vacuum during steady operation is also about -49.0 kPa (-5 mAq).

  When the degree of vacuum of the solid-liquid recovery tank 3 becomes −46.5 kPa (−4.75 mAq) to −51.4 kPa (−5.25 mAq), the suction transport valve 18 is opened rapidly. As a result, as shown in FIG. 10, the water containing the settling sand in the settling basin 1 is sucked into the suction transport pipe 2 as the solid-liquid mixture 9. At this time, if necessary, water is jetted from the water jet nozzle 19 to fluidize the sand and make it easy to suck the sand from the opening of the end 2a. In this way, water is jetted from the water jet nozzle 19 to fluidize the sand in the sand basin 1 and the suction transport valve 18 of the suction transport pipe 2 is opened, so that the end 2a of the suction transport pipe 2 is opened. While collecting the sand in the sand basin 1 in the vicinity of the opening, as shown in FIG. 10, water containing the sand in the sand basin 1 is sucked into the suction transport pipe 2 as a solid-liquid mixture 9. At this time, if necessary, water may be continuously ejected from some of the water ejection nozzles 19. The concentration of the sand in the solid-liquid mixture 9 is 20 to 35%, preferably about 30% on average. Thereby, the sand transport efficiency can be stabilized and improved.

  Then, as shown in FIG. 11, the air injection valve 15 is opened for 1 to 4 seconds, and a pressure higher than the water level of the sand basin 1, for example, pressurized air of 20 kPa to 50 kPa is injected into the suction transport pipe 2. Thus, the upper part of the solid-liquid mixture 9 shown in FIG. 10, that is, the upper part of the solid-liquid mixture 9 above the connection part 12a of the air injection pipe 12 is moved to the vicinity of the connection part 7a of the atmosphere release pipe 7 or above it. To rise.

  Next, the air release valve 6 is opened, the air injection valve 15 is closed, and the connection portion 7a of the atmosphere release pipe 7 is opened to the atmosphere, whereby a long water column 11 for transportation is formed as shown in FIG. This long water column 11 for transporting is due to the pressure difference between the degree of vacuum acting on the end portion on the solid-liquid recovery tank 3 side and the atmospheric pressure acting on the end portion on the open side of the atmosphere. As shown in FIG. 2, the liquid moves toward the solid-liquid recovery tank 3 and is transported.

  The control unit 20 closes the atmosphere release valve 6 again immediately before the entire transport water column 11 enters the solid-liquid recovery tank 3. As a result, as shown in FIG. 10, the solid-liquid mixture 9 containing the sand and water in the sand basin 1 is again sucked into the suction transport pipe 2. Thereafter, by repeating the same process as described above, the sediment deposited on the bottom of the sedimentation basin 1 is intermittently transported to the solid-liquid recovery tank 3. In addition, the time for which the air release valve 6 is open is 2 to 10 seconds. This opening time can be changed according to the lift and transport distance.

  When releasing the atmosphere through the atmosphere release valve 6, it is important to allow a large amount of air to flow in in a short time with almost no loss. It is preferable to transport the sand efficiently by avoiding air from entering and mixing below the water column 11 for transport. Further, as the long transport water column 11 is transported in the suction transport pipe 2 as indicated by 11-1 and 11-2 in FIG. 12, the separation of the sand and water and the mixing of the sucked air proceed. Therefore, the water column 11 for transportation collapses from the original shape. For this reason, in this embodiment, even when the transport water column 11 is in the state of 11-1 and 11-2 so that no air communication path is formed in the suction transport pipe 2, the inner wall of the suction transport pipe 2 is always It is preferred to keep the sealed portion in place.

  Here, maintaining the state where the sealed portion is always maintained may maintain a state where at least a part of the suction transport pipe 2 is sealed by the transport water columns 11, 11-1, 11-2. In order to avoid the risk of being difficult to be sealed at the transport water columns 11, 11-1, 11-2 and to maintain more certainty, the air release valve 6 is changed from the open state to the closed state, and the air injection valve 15 is also closed. The controller 20 controls the opening / closing timing of the air release valve 6 so that the suction of the solid-liquid mixture 9 is started and the vacuum of the solid-liquid recovery tank 3 acts on the entire inside of the suction transport pipe 2. May be. Since the opening / closing timing varies depending on the state of sand settling in the sand basin 1, that is, the properties of the solid-liquid mixture 9, the transport distance, and the like, it is preferable to determine the optimum opening / closing timing, opening / closing time, etc. by trial operation.

  Therefore, the diameter of the suction transport pipe 2 is 50A to 125A, preferably 65A to 100A, and the diameter of the air release valve 6 is not less than 1/2 of the diameter of the suction transport pipe 2 and not more than the diameter of the suction transport pipe 2. The diameter of the air injection pipe 12 is 32A to 50A, and it is preferably a valve capable of rapid opening and closing for 1 second or less, preferably 0.5 seconds or less. Moreover, it is preferable that the atmosphere release valve 6 and the air injection valve 15 are valves that can be fully opened and closed, and that the opening area when fully opened is approximately equal to that of the atmosphere release pipe 7 and the air injection pipe 12. Furthermore, it is also important that the atmosphere release pipe 7 and the air injection pipe 12 are connected to the suction transport pipe 2 at a predetermined angle with respect to the horizontal plane, preferably 50 to 70 degrees. This is because even if a solid matter of a solid-liquid mixture, that is, sedimentation, slightly enters each pipe, it is easily re-sucked into the suction transport pipe 2 by its angle of repose so that no pressure loss in operation occurs. This is to enable atmospheric suction or pressurized air injection.

  When the air injection valve 15 is opened, the pressurized air is smoothly injected into the suction transport pipe 2 at a stretch, and the solid-liquid mixture is pushed up to the connection portion 7a of the air release pipe 7 in a piston flow. It is preferable for forming a long water column for transportation. In this case, also in the first and second embodiments, the water level (height) of the solid-liquid mixture sucked into the suction transport pipe 2 by the vacuum pump 4 is approximately the same as long as the same degree of vacuum acts. Become. However, in the second embodiment, pressurized air from an air injection pipe 12 provided in the sand basin 1 is injected for a very short time of several seconds or less, and the sucked solid-liquid mixture is piston-flowed. By pushing up at once, a long water column for transportation with higher sedimentation concentration is formed.

  Next, at the same time as closing the air injection valve 15, the atmosphere release valve 6 is opened, and the lower part of the solid-liquid mixture pushed up to the connection part 7 a of the atmosphere release pipe 7, that is, the connection part 7 a of the atmosphere release pipe 7, Air at atmospheric pressure is sucked smoothly and all at once, and the solid-liquid mixture above the connection portion 7a is sucked in a piston flow by the action of the degree of vacuum of the solid-liquid recovery tank 3 to form a water column for transportation. . The longer the injection of pressurized air and the air suction at atmospheric pressure is smoothly performed in a short time in a single piston flow, the more easily air enters the transport water column that is formed. It becomes difficult to be transported in a fluid manner, and the shape of the water column for transportation collapses, that is, the sand and the liquid are separated. On the other hand, the solid-liquid mixture part below the connection part 12a of the air injection pipe 12 moves toward the sand basin.

  The time from the fully open to fully closed air release valve 6 is 2 to 10 seconds, the time from fully closed to fully open is 1 to 5 seconds, and the time that the air injection valve 15 is fully open is 1 to 4 seconds. Is approximately the same as the time during which the air release valve 6 is fully open. In the example shown in FIG. 8, the time for which the air release valve 6 is fully open is 5 seconds, the time for which it is fully closed is 3 seconds, and the time for which the air injection valve 15 is fully open is set to an extremely short time of about 3 seconds. is doing. The timing for closing the air injection valve 15 is preferably within 2 seconds immediately after the atmospheric release valve 6 is fully opened. Thus, the fully open time and the fully closed time of the atmosphere release valve 6 and the air injection valve 15 are short.

  In FIG. 9, the opening / closing timing of the air injection valve 15 and the atmosphere release valve 6 is shown including the time required for the valve to be opened and closed quickly. Therefore, both the air injection valve 15 and the atmosphere release valve 6 can be fully opened and fully closed, and the time required for full opening and full closing, that is, the time required for rapid opening and sudden closing is extremely short, and the specification has little pressure loss. It is important to choose one. In addition, the timing of signal transmission for the opening / closing must be determined appropriately according to the valve specifications. And it is important for the control part 20 to control these valves correctly.

  As described above, when the transport water column 11 is transported, the air release valve 6 is opened to suck the air. At this time, since the transport water column 11 is between the atmosphere and the solid-liquid recovery tank 3, the air does not directly flow into the solid-liquid recovery tank 3. However, since the transport water column 11 has considerable kinetic energy before the solid-liquid recovery tank 3, all of it is transported into the solid-liquid recovery tank 3 before closing the air release valve 6. There is a fear. When air is communicated between the opened air release valve 6 and the solid-liquid recovery tank 3, air having good fluidity flows into the solid-liquid recovery tank 3 in a short time, and the vacuum Decrease the degree. As a means for avoiding this, only a control method using a timer may be employed. However, since the transport speed of the transport water column 11 varies depending on the concentration (specific gravity) of sedimentation or its length, stable operation is possible. For this purpose, not only the vacuum sensor (not shown) of the solid-liquid recovery tank 3 itself, but also a vacuum sensor 14 is installed in the suction transport pipe 2 in front of the solid-liquid recovery tank 3 as shown in FIG. It is preferable to do this. In this case, it is confirmed by the vacuum sensor 14 that the transport water column 11 has passed and the atmospheric pressure has been reached, and this is used as an auxiliary to the timer control for closing the atmosphere release valve 6.

  FIG. 14 is a schematic diagram showing a configuration example of the sand transporting device in the second embodiment, and FIG. 15 is an example of a measured value of the degree of vacuum obtained from an experiment using the sand transporting device shown in FIG. It is a graph to show. In the sand transporting apparatus shown in FIG. 14, the vacuum degree sensor 14 is disposed on the upper surface of the horizontal pipe extending from the second end 2 b and at a position 10 m from the second end 2 b. The vacuum degree sensor 14 is connected to a monitoring device 21, and the degree of vacuum in the suction transport pipe 2 detected by the vacuum degree sensor 14 is monitored by the monitoring device 21.

  As shown in FIG. 15, when the sand transporting apparatus is operating normally, a graph is obtained in which a mountain-shaped curve having a portion with a high degree of vacuum continues while the degree of vacuum rises and falls as a whole. By using this graph or by directly using the detected value of the degree of vacuum, the water column for transportation passing through the suction transportation pipe 2 can be detected. That is, in the graph of FIG. 15, by detecting that the degree of vacuum has changed from a high level (H) to a low level (L), it is possible to detect that the transport water column 11 has passed. In addition, when the degree of vacuum is changed from the low level (L) to the high level (H), the solid-liquid mixture is sucked, and the transport water column is formed at the lower end of the suction transport pipe 2 of the sand basin 1. Is detected. Thus, it can be seen that one Yamatani-shaped curve indicating the change in the degree of vacuum corresponds to one transport water column process, that is, one transported water column. Therefore, the number of transported water columns can be determined based on the number of peaks of the variation in the degree of vacuum.

  When the change in the degree of vacuum is examined in more detail, the degree of vacuum generally decreases until the air release valve 6 is fully closed from the fully opened second half part, and after the fully closed state, the degree of vacuum is increased. Finally, the degree of vacuum reaches a set value when the operation of the solid-liquid recovery tank 3 is repeated. Thereafter, the degree of vacuum decreases again from the fully opened second half of the air release valve 6. The value of the degree of vacuum that changes in this way varies depending on the initial set degree of vacuum of the solid-liquid recovery tank 3. For example, when the initial set degree of vacuum of the solid-liquid recovery tank 3 is set to −60 kPa, the level of low vacuum (L ) To −40 kPa to −40 kPa, and high level (H) to −40 kPa to −50 kPa. Therefore, when such a change in the degree of vacuum is not exhibited, for example, if the low degree of vacuum continues for a certain time or more, for example, 5 to 10 seconds or more, the atmosphere open pipe 7 and the solid-liquid recovery tank 3 are in communication. That is, it is determined that an abnormal situation has occurred in which the transport water column is not transported.

  If the state of high vacuum continues for a certain time or more, for example, 5 to 10 several seconds, for example, the suction transport pipe 2 may be moved between the opening 2a of the suction transport pipe 2 and the installation position of the vacuum sensor 14 for some reason. When clogging, valve malfunction, etc. occur and the degree of vacuum of the solid-liquid recovery tank 3 is directly applied to the degree-of-vacuum sensor 14, that is, an abnormal situation occurs in which the transport water column is not transported. To be judged. By considering such a change in the degree of vacuum of the degree-of-vacuum sensor 14 and the state of the process set by the timer, it can be determined whether or not the sand transporting apparatus is operating normally. That is, if the degree of vacuum of the degree-of-vacuum sensor 14 indicates an abnormal state, the control unit 20 can issue an alarm or can be used for control to stop the apparatus. Specifically, as described above, the degree of vacuum is detected by the degree-of-vacuum sensor 14 and the monitoring device 21 having a function of converting the degree of vacuum and a graph display function of the detected degree of change in vacuum is used to display a low vacuum level (L) from the displayed graph. A method of detecting a high level (H) and sending a signal to the control unit 20 or without having a graph display function, directly sending a low vacuum level (L) and a high level (H) signal to the control unit 20 , There are ways to handle.

  As shown in FIGS. 8 and 9, the solid-liquid mixture suction step starts when the air release valve 6 is fully closed and the air injection valve 15 is fully closed, and ends when the air injection valve 15 starts to open. The transport water column forming process starts when the air injection valve 15 starts to open and ends when the air injection valve 15 closes. The transport process starts with the start of the opening operation of the atmosphere release valve 6. At this time, the air injection valve 15 is being closed or has been closed. As described above, the opening / closing operation of the atmosphere release valve 6 and the air injection valve 15 is performed as shown in the example of FIG. 9, and the transportation process is started and finished. As shown in the example of FIG. 9, it is necessary to set a timer appropriately so that each of these processes is performed optimally. The control status of the air injection valve 15 and the atmosphere release valve 6 is as shown in FIG. 9 and is mainly a timer, but the degree of vacuum at which the monitoring device 21 can detect the change in the degree of vacuum shown in FIG. 14 as an auxiliary sensor. A sensor 14 is preferably provided. In the first embodiment described above, the degree of vacuum that periodically changes is detected by the degree-of-vacuum sensor 14 (see FIG. 6) provided in the suction transport pipe 2. Therefore, also in the first embodiment, similarly to the second embodiment, it is possible to detect the number of water columns for transportation, the operation status of the apparatus, and the like from the change in the degree of vacuum.

  The suction transport valve 18 is in a fully closed state until the degree of vacuum in the solid-liquid recovery tank 3 reaches a predetermined value, but thereafter it is in a fully open state until the sand transporting process is completed. Further, it is preferable that the suction transport valve 18 can be rapidly opened and closed and fully opened and fully closed so that the degree of vacuum acts in the suction transport pipe 2 quickly. In addition, the installation position of the suction transport valve 18 may be between the connection portion 7a of the air release pipe 7 and the end portion 2b connected to the solid-liquid recovery tank 3, but the vertical piping portion is easy to maintain and manage. It is preferable to provide it.

  Further, it is preferable that the diameter of the suction transport valve 18 when fully opened is about the same diameter as the suction transport pipe 2. In order for the degree of vacuum to act quickly on the solid-liquid mixture 9 of sand and water and the water column 11 for transport without loss, the suction transport valve 18 is a valve of a specification that does not cause biting such as sand sediment, such as a straight diaphragm valve. Or a ball valve or the like.

  Then, when the formation and transportation of the transport water column 11 described above is repeated 50 to 150 times, the solid-liquid recovery tank 3 becomes full as shown in FIG. Note that the number of repetitions increases as the amount of sedimentation and the solid-liquid recovery tank capacity increase. When the solid-liquid recovery tank 3 becomes full, the control unit 20 stops the operation of the valves including the air release valve 6, the air injection valve 15, the suction transport valve 18, the vacuum pump 4, and the compressor 16.

  After the settling of sand has settled in the lower part of the solid-liquid collection tank 3, the supernatant water discharge valve 21 and the ventilation valve 22 attached to the solid-liquid collection tank 3 are opened, and the supernatant water in the solid-liquid collection tank 3 is discharged. Thereafter, the supernatant water discharge valve 21 is closed, and the air washing valve 23 provided at the bottom of the solid-liquid recovery tank 3 is opened, so that the air from the compressor 16 is sent into the solid-liquid collection tank 3 and the sand is washed with air. I do. Next, the air washing valve 23 is closed, the water washing valve 24 is opened, and the sand is washed with water. After the water cleaning is completed, the water cleaning valve 24 is closed. Then, after opening the supernatant water discharge valve 21 again, the sand sediment discharge valve 5 provided at the bottom is opened, and the sand in the solid-liquid recovery tank 3 is discharged together with water.

For example, one cup of effective capacity (sand and the total amount of water) 1.0 m ³ per solid-liquid recovery tank ^3, 0.2~0.35m 3, to discharge the usual 0.3 m ³ approximately sand. After discharging the settling sand, start the sand transport operation again if necessary.

  When the control unit 20 opens the atmosphere release valve 6 and closes the air injection valve 15, the water level of the solid-liquid mixture 9 in the suction transport pipe 2 needs to be above the connection part 7 a of the atmosphere release pipe 7. is there. The timing at which the control unit 20 opens and closes the atmosphere release valve 6 and the air injection valve 15 is usually controlled by time, but the sensor for measuring the degree of vacuum of the solid-liquid recovery tank 3 and the water level of the suction transport pipe 2 are measured. Auxiliary control may be performed using the output of the sensor.

  The control unit 20 sets the opening time and closing time of the air injection valve 15 and the atmospheric release valve 6, the timing thereof, the speed of opening and closing of these valves, confirmation of full opening and closing, a signal from the vacuum sensor 14, a solid-liquid recovery tank The operation control of the vacuum pump 4 by the degree of vacuum of 3 may be performed, and other necessary control functions may be simultaneously provided. When a slurry such as sand settling is targeted, the actual sand transport pipe 2 is made of SUS304 and has a thick wall thickness such as Sch40 to maintain wear resistance. Therefore, the entire sand transporting pipe 2 is opaque and is not a transparent pipe that can visually observe the formation of the water column for transportation and the transportation state thereof. Therefore, the formation of the water column for transportation and the observation of whether or not the transportation process is normally performed are the transmission signals for opening and closing the atmosphere release valve 6, the time required for opening, the time required for closing, and the time for the fully open and fully closed state What can be performed based on the signal of the vacuum degree sensor 14 together with the timer setting such as the above is very effective in implementing the sand transporting apparatus of the present invention.

  The diameter of the opening of the end portion 2 a of the suction transport pipe 2 is preferably set to be ½ or more of the diameter of the suction transport pipe 2. This is because if the caliber is too small, it may be clogged with sedimentation, and if it is too large, the suction flow rate will be too small. When the degree of vacuum of the solid-liquid recovery tank 3 is −48.8 kPa (−5 mAq), the diameter of the suction transport pipe 2 is 80 A, and the diameter of the opening of the end 2 a is, for example, ½, the suction flow rate is suction transport It becomes as high as 6 to 10 m / sec, which is four times the normal value of 1.5 to 2.5 m / sec, so that pebbles and the like can be sucked and not clogged. The transport velocity of the solid mixture 9 in the suction transport pipe 2 is maintained at 3 to 15 m / second, usually 6 to 7 m / second or more, and sand is drawn in the horizontal pulling pipe portions 2 c and 2 d of the suction transport pipe 2. There is no residue.

  Moreover, since pressurized air distribute | circulates the air injection pipe | tube 12, the thing of the diameter of 25A-50A which can be installed structurally can be used. Further, since the air injection valve 15 to be used is for pressurized air, an electromagnetic valve may be used, but a specification with little pressure loss is preferable.

  As described above, according to the second embodiment of the present invention, pressure is applied from the air injection pipe 12 toward the opening of the end 2a of the suction transport pipe 2 with the suction transport valve 18 fully closed. By the operation of sending in air, it is possible to blow away sand sediments in the vicinity of the opening portion of the end portion 2a of the suction transport pipe 2 as necessary, and the clogging of the opening portion can be prevented.

  Further, the suction transport valve 18, the air release valve 6, and the air injection valve 15 are closed, and before starting the operation, the vacuum pump 4 is driven in advance to reach the solid-liquid recovery tank 3 and the suction transport valve 18 of the suction transport pipe 2. By setting the degree of vacuum to a predetermined value, the time for forming the vacuum shown in FIG. 8 can be omitted, and the main operation can be performed immediately.

  Further, as shown in FIG. 13, a vacuum degree sensor 14 may be provided in the suction transport pipe 2 in front of the solid-liquid recovery tank 3. Furthermore, an auxiliary air tank 17 may be provided in the air injection pipe 12 for storing air from the compressor 16 in order to send air into the suction transport pipe 2 at a stretch. This auxiliary air tank 17 has a volume of 1.0 to 2.0 times the capacity corresponding to the length from the connection part 12a of the air injection pipe 12 of the suction transport pipe 2 to the connection part 7a of the air release pipe 7. It is preferable. Air may be stored in the auxiliary air tank 17 during the transport time (2 to 10 seconds) of the transport water column 11. Furthermore, if the auxiliary air tank 17 having a certain capacity is provided, the amount of air injected at a time can be easily controlled by adjusting the pressure from the compressor 16 that injects air into the auxiliary air tank 17.

  As described above, according to the second embodiment, the solid-liquid mixture 9 above the connection portion 12a of the air injection pipe 12 is sucked by sending air from the auxiliary air tank 17 into the suction transport pipe 2 at a stretch. It can be pushed up by the length from the connection part 12a of the air injection pipe 12 of the transport pipe 2 to the connection part 7a of the air release pipe 7. Thereby, the water column 11 for transport longer than the water column 10 for transport in 1st Embodiment can be formed above the connection part 7a of the air release pipe 7. FIG. As described above, in the second embodiment, the transport water column transported at one time can be increased from 2.3 m to 3.3 m, for example. Since the concentration can be reduced from 25% to 30%, efficient sand transport can be realized. Furthermore, it is possible to operate with a conventional power usage of 10 to 15% (high pressure water pump or vacuum pump).

Experiments were conducted under the following conditions using the sand transporting apparatus shown in FIG. The material of the main equipment of this apparatus was SUS304.
-Initial vacuum degree of the solid-liquid recovery tank 3: -58.8 kPa (-6 mAq)
-Normal fluctuation range of the degree of vacuum of the solid-liquid recovery tank 3: -44.1 kPa (-4.5 mAq) to -53.9 kPa (-5.5 mAq)
・ Suction transport pipe 2: 80A diameter
-Opening at the end 2a of the suction transport pipe 2: aperture 65A
-Bending part 2f of suction transport pipe 2: Bend pipe x 3 pieces with a bending radius of 0.8 m-Solid-liquid recovery tank 3: Total capacity 1.5 m ³ , Effective capacity 1.0 m ³
・ Vacuum degree sensor 14: manufactured by Kyowa Denki Co., Ltd., high precision small pressure transducer (model: PGM-H)
・ Vacuum pump 4: Power 7.5kW
・ Air release valve 6: Diameter 50A, Pneumatically operated ball valve, rapid opening speed and rapid closing speed 1 second ・ Air release pipe 7: Diameter 50A

Here, the lift (H ₁ ), the total transport distance of the suction transport pipe 2, and the horizontal lengths (L ₁ ) of the horizontal piping sections 2 c and 2 d of the suction transport pipe 2 are changed, and the atmosphere is released to meet these conditions. The opening / closing time of the valve 6 and the number of transportations required until the solid-liquid recovery tank 3 became full were obtained. The results are shown in Table 1.

  As shown in Table 1, good results were obtained in any of Experimental Examples 1, 2, and 3. The transported sand concentration varied from 20-35%, with an average of 27%. The average specific gravity of the sucked solid-liquid mixture was 1.5. Furthermore, the highest water level (HWL) of the sand basin 1 was 0.8 m, and the length of the water column for transportation at this time was 2.5 to 3.1 m (average 2.8 m). At this time, the transportation speed of the water column for transportation fluctuates depending on the concentration of the sediment of the solid-liquid mixture and shows 3 to 15 m / sec. In the results shown in Table 1, the total transportation distance is set to open the air release valve. It was a value divided by the time (transportation time) during which it was 6 to 7 m / sec on average. Moreover, the suction speed at this time was similarly fluctuate | varied with the density | concentration of the sedimentation of a solid-liquid mixture, and showed 1.5-2.5 m / sec. In Table 1, the set value of 3 seconds for the time during which the air release valve is closed (suction time) is a time with a margin until the height of the solid-liquid mixture is stabilized.

An experiment was conducted under the following conditions using a sand transporting device provided with the sand transporting valve 18 shown in FIG. The material of the main equipment of this apparatus was SUS304.
-Normal fluctuation range of the degree of vacuum from the solid-liquid recovery tank to the suction transfer valve: -44.1 kPa (-4.5 mAq) to -53.9 kPa (-5.5 mAq)
・ Suction transport pipe 2: 80A diameter
Suction transport valve 18: aperture 80A, pneumatically actuated straight diaphragm valve. Opening of end 2a of suction transport tube 2: aperture 65A
-Bending part 2f of suction transport pipe 2: Bend pipe x 3 pieces with a bending radius of 0.8 m-Solid-liquid recovery tank 3: Total capacity 1.5 m ³ , Effective capacity 1.0 m ³
・ Vacuum degree sensor 14: manufactured by Kyowa Denki Co., Ltd., high precision small pressure transducer (model: PGM-H)
・ Vacuum pump 4: Power 7.5kW
・ Air release valve 6: Diameter 50A, Pneumatically operated ball valve, rapid opening speed and rapid closing speed 1 second ・ Air release pipe 7: Diameter 50A
Air injection valve 15: aperture 40A, pneumatically operated ball valve, rapid opening speed and rapid closing speed 0.5 sec. Air injection tube 12: aperture 40A

Here, the lift (H ₂ ), the total transport distance of the suction transport pipe 2, and the horizontal lengths (L ₂ ) of the horizontal pulling pipe portions 2 c and 2 d of the suction transport pipe 2 are changed, and the atmosphere is opened to meet these conditions. The opening / closing time of the valve 6 and the number of transportations required until the solid-liquid recovery tank 3 became full were obtained. As a comparative experiment, the same experiment was also performed when the air injection pipe 12 and the air injection valve 15 were not used. The results are shown in Table 2.

  As shown in Table 2, good results were obtained in any of Experimental Examples 4, 5, and 6. The transported sand concentration varied from 20-35%, with an average of 30%. The average specific gravity of the sucked solid-liquid mixture was 1.5. Furthermore, the highest water level (HWL) of the sand basin 1 was 2.3 m, and the length of the water column for transportation at this time was 3.0 to 3.6 m (average 3.3 m). On the other hand, the length of the water column for transport in the comparative experiment not using the air injection valve was as short as 2.0 to 2.6 m (average 2.3 m). At this time, the transportation speed of the water column for transportation fluctuates depending on the sediment concentration of the solid-liquid mixture and shows 3 to 15 m / sec. However, in the results shown in Table 2, the total transportation distance is set to open the air release valve. It was a value divided by the time (transportation time) during which it was 6 to 7 m / sec on average. Moreover, the suction speed of the solid-liquid mixture at this time was similarly fluctuate | varied with the density | concentration of the sedimentation of a solid-liquid mixture, and showed 1.5-2.5 m / sec. After injecting 40 kPa of pressurized air from the air injection valve for 2.5 seconds, the air release valve was opened and the air injection valve was closed at the same time.

Experiments were conducted under the following conditions using the sand transporting apparatus shown in FIG. Although the suction transport pipe 2 has a diameter of 100A, if the suction transport pipe 2 has a diameter of 100A, the opening area is about 1.8 times that of 80A. A 15 kW vacuum pump with performance was used.
-Normal fluctuation range of the degree of vacuum from the solid-liquid recovery tank to the suction transfer valve: -44.1 kPa (-4.5 mAq) to -53.9 kPa (-5.5 mAq)
- lift _(H 2): 20m
· Horizontal length of the suction transport tube _(L 2): 12m
・ Total transport distance: 32m
Suction transport valve 18: aperture 100A, pneumatically actuated straight type diaphragm valve Opening of end 2a of suction transport tube 2: aperture 80A
-Bending part 2f of suction transport pipe 2: 3 bend pipes with a bending radius of 1.0 m * Solid-liquid recovery tank 3: Total capacity 1.5 m ³ , Effective capacity 1.0 m ³
・ Vacuum degree sensor 14: manufactured by Kyowa Denki Co., Ltd., high precision small pressure transducer (model: PGM-H)
-Atmospheric release valve 6: aperture 65A, pneumatically operated ball valve, rapid opening speed and rapid closing speed 1 second-Atmospheric release tube 7: aperture 65A
・ Air injection valve 15: Diameter 50A, Pneumatically operated ball valve, rapid opening speed and rapid closing speed 0.5 seconds ・ Air injection pipe 12: Diameter 50A

  As a result, it was found that even if the diameter of the suction transport pipe 2 was increased to 100A, the same good result as that when the suction transport pipe 2 had a diameter of 80A could be obtained by selecting a vacuum pump 4 corresponding thereto. . The transported sand concentration varied from 20-35%, with an average of 30%. Further, the number of transportation required for the collection tank 3 to become full was 40 times. Furthermore, the time required for transportation was as short as about 6 minutes.

An experiment for detecting the degree of vacuum of the degree-of-vacuum sensor 14 was performed under the following conditions using the sand transporting apparatus shown in FIG. The material of the main equipment of this apparatus was SUS304.
-Normal fluctuation range of the degree of vacuum from the solid-liquid recovery tank to the suction transfer valve: -44.1 kPa (-4.5 mAq) to -53.9 kPa (-5.5 mAq)
・ Suction transport pipe 2: 80A diameter
Suction transport valve 18: aperture 80A, pneumatically actuated straight diaphragm valve. Opening of end 2a of suction transport tube 2: aperture 65A
-Bending part 2f of suction transport pipe 2: Bend pipe x 5 pieces with a bending radius of 0.8 m-Solid-liquid recovery tank 3: Total capacity 1.5 m ³ , Effective capacity 1.0 m ³
・ Vacuum degree sensor 14: A high-precision small pressure transducer (model: PGM-H) manufactured by Kyowa Denki Co., Ltd. is installed in the horizontal piping.
・ Vacuum pump 4: Power 7.5kW
・ Air release valve 6: Diameter 50A, Pneumatically operated ball valve, rapid opening speed and rapid closing speed 1 second ・ Air release pipe: Diameter 50A
・ Air injection valve 15: aperture 40A, pneumatically operated ball valve, rapid opening speed and rapid closing speed 0.5 seconds ・ Air injection tube: aperture 40A

  A vacuum degree sensor 14 is installed on the upper surface of the horizontal pulling pipe section 10 m away from the connection end 2 b of the suction transport pipe 2 and the solid-liquid recovery tank 3, and depending on the opening / closing timing of the air release valve 6 and the air injection valve 15 as shown in FIG. Sedimentation and transportation of sand was carried out. The detection value of the vacuum degree sensor 14 was sent to a monitoring device 21 having a vacuum degree converter and a graph display by a cable, and a change graph of the vacuum degree at that time was obtained. FIG. 15 shows this result.

  As a whole, a valley-shaped curve having a mountain with a high degree of vacuum was continuously obtained while the degree of vacuum increased and decreased. The degree of vacuum is -20 kPa to -40 kPa at a low level (L) until the air injection valve and the air release valve are closed and the solid-liquid mixture of water and sediment is sucked into the suction transport pipe and the water column for transport is formed. From -40 kPa to -50 kPa of high level (H), it was found that when the air release valve was opened and transportation started, the high level (H) shifted to the low level (L). And by repeating this, it was found that sanding and transportation could be done normally. One Yamaya type corresponds to one suction / transport process of the transport water column, that is, one transported water column. In FIG. 15, 31 suctions / transports were performed and the process was completed.

  In addition, it was found that when the low level (L) degree of vacuum lasts for a set time or longer, an abnormal situation occurs in which the water column for transportation cannot be transported through communication between the open air pipe and the solid-liquid recovery tank. Furthermore, if the high level (H) degree of vacuum continues for a set time or longer, the liquid is recovered due to clogging or malfunction of the valve between the suction port and the vacuum sensor installation position. It was found that an abnormal situation occurred in which the water column for transportation was not transported only by the high vacuum of the tank directly applied. Then, it was found that these abnormal situations were transmitted from the monitoring device 21 to the control unit, and an alarm such as a process abnormality was issued, which can be applied to the overall control.

  Table 3 shows the result of comparing the above-described sand-carrying device according to the present invention with a conventional sand-carrying device (high-pressure water ejector-type sand-carrying device, mixed-air jet-type sand-carrying device that mixes air with high-pressure water). Shown in

  From Table 3, it can be seen that the sand transporting device according to the present invention can save energy compared to the conventional sand transporting device, has a high lift and a long transport distance. Thus, the sand transporting apparatus according to the present invention is extremely efficient.

  As shown in Table 3, the high-pressure water ejector type sand transporting device required a high-pressure water pump with a capacity of about 75 kW, but according to the sand transporting device according to the present invention, the conventional 10-15% It becomes possible to operate with the power used (vacuum pump). In addition, it can lift the sand from the sand basin and transport it to a high lift of 5m to 70m. And since the main apparatus of a sand transporting apparatus can be made small and the freedom degree of arrangement | positioning of a suction transport pipe is high, the freedom degree of the installation with respect to the whole apparatus can be improved, and the whole apparatus system can be made compact.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various forms within the scope of the technical idea.

It is a schematic diagram which shows the structure of the sand transporting apparatus in the 1st Embodiment of this invention. It is a timing chart which shows operation | movement of the sand transporting apparatus of FIG. It is a schematic diagram which shows operation | movement of the sand transport apparatus of FIG. It is a schematic diagram which shows operation | movement of the sand transport apparatus of FIG. It is a schematic diagram which shows operation | movement of the sand transport apparatus of FIG. It is a schematic diagram which shows the modification of the sand transporting apparatus of FIG. It is a schematic diagram which shows the structure of the sand transporting apparatus in the 2nd Embodiment of this invention. It is a timing chart which shows operation | movement of the sand transporting apparatus of FIG. It is a timing chart which shows the opening / closing operation | movement of the air injection valve of the sand transporting apparatus of FIG. It is a schematic diagram which shows operation | movement of the sand transport apparatus of FIG. It is a schematic diagram which shows operation | movement of the sand transport apparatus of FIG. It is a schematic diagram which shows operation | movement of the sand transport apparatus of FIG. It is a schematic diagram which shows the modification of the sand transporting apparatus of FIG. It is a schematic diagram which shows the structural example of the sand transporting apparatus in 2nd Embodiment. It is a graph which shows an example of the measured value of the vacuum degree obtained from the experiment using the sand transporting apparatus shown in FIG.

Explanation of symbols

1 Sedimentation basin 2 Suction transport pipe 2a First end (opening)
2b 2nd end part 2c, 2d Horizontal pulling pipe part 2e Vertical piping part 2f Bending part 3 Solid-liquid recovery tank 4 Vacuum pump (pressure reduction device)
6 Atmospheric release valve 7 Atmospheric release pipe 7a Connection unit 8 Control unit 9 Solid-liquid mixture 10, 11 Water column 12 for transportation 12 Air injection tube 12a Connection unit 14 Vacuum degree sensor 15 Air injection valve 16 Compressor (air transfer device)
17 Auxiliary air tank 18 Suction transport valve 19 Water injection nozzle 20 Control unit 21 Monitoring device 22 Ventilation valve

Claims (13)

A solid-liquid recovery tank;
A suction transport pipe having a first end immersed in the water of the sand basin and a second end connected to the solid-liquid recovery tank;
A decompression device for decompressing the interior of the solid-liquid recovery tank and the suction transport pipe;
An open air pipe connected to the suction transport pipe at a position above the highest water level of the sand basin;
An atmosphere release valve for releasing the connection between the suction transport pipe and the atmosphere release pipe through the atmosphere release pipe;
When the air release valve is closed and the sediment deposited in the sand basin is sucked into the suction transport pipe together with water as a solid-liquid mixture, the water level rises above the connection with the air release pipe. A water column for transportation is formed above the connection portion by opening the atmosphere release valve, and the water column for transportation is formed by the difference between the atmospheric pressure acting on the water column for transportation and the degree of vacuum of the solid-liquid recovery tank. The transport water column is formed and transported by closing the air release valve and repeating opening and closing of the air release valve immediately before the entire transport water column enters the solid-liquid recovery tank. A repeating control unit;
A sand transporting device characterized by comprising: A solid-liquid recovery tank;
A suction transport pipe having a first end immersed in the water of the sand basin and a second end connected to the solid-liquid recovery tank;
A decompression device for decompressing the interior of the solid-liquid recovery tank and the suction transport pipe;
An open air pipe connected to the suction transport pipe at a position above the highest water level of the sand basin;
An atmosphere release valve for releasing the connection between the suction transport pipe and the atmosphere release pipe through the atmosphere release pipe;
An air injection pipe connected to the suction transport pipe in the water of the sand basin;
An air transfer device for sending air into the suction transport pipe;
An air injection valve for injecting air into the suction transport pipe from the connection with the air injection pipe of the suction transport pipe by the air transfer device through the air injection pipe;
When the air release valve and the air injection valve are closed and the sediment deposited in the sand basin is sucked into the suction transport pipe as a solid-liquid mixture together with water, and the water level rises above the water level of the sand basin By opening the air injection valve to push up the solid-liquid mixture above the connection with the air injection pipe, opening the atmosphere release valve and closing the air injection valve to A transport water column is formed above the connecting portion, and the transport water column is transported to the solid-liquid recovery tank by a difference between an atmospheric pressure acting on the transport water column and a vacuum degree of the solid-liquid recovery tank, Immediately before the entire water column for transportation enters the solid-liquid recovery tank, the air release valve is closed, and the formation and transportation of the transportation water column are repeated by repeatedly opening and closing the air release valve and the air injection valve. And a control unit,
A sand transporting device characterized by comprising:   The first end of the suction transport pipe has a shape in which the inner diameter gradually decreases so as to have an inclination of 50 degrees to 70 degrees, and the minimum diameter of the opening is 1 / diameter of the diameter of the suction transport pipe. The sand transporting apparatus according to claim 1 or 2, wherein there are two or more.   The sand transportation according to any one of claims 1 to 3, further comprising a water injection nozzle that fluidizes the sand settling near the first end of the suction transport pipe by water injection. apparatus.   The sand transporting device according to any one of claims 1 to 4, further comprising a suction transport valve provided above a connection portion of the air release tube of the suction transport tube. The atmosphere open pipe is connected to the suction transport pipe at an angle of 50 degrees to 70 degrees with respect to a horizontal plane;
The inner diameter of the atmosphere release pipe is ½ or more of the diameter of the suction transport pipe and is equal to or smaller than the diameter of the suction transport pipe,
3. The sand transporting apparatus according to claim 1, wherein an opening area when the atmosphere release valve is fully opened is substantially the same as a cross-sectional area of the atmosphere release pipe. The air injection pipe is connected to the suction transport pipe at an angle of 50 degrees to 70 degrees with respect to a horizontal plane;
3. The sand transporting apparatus according to claim 2, wherein an opening area when the air injection valve is fully opened is substantially the same as a cross-sectional area of the air injection pipe. A vacuum degree sensor for detecting the degree of vacuum in the suction transport pipe is provided at a position 3 to 15 m away from the second end of the suction transport pipe,
The sand transporting apparatus according to claim 1 or 2, further comprising a monitoring device for monitoring the degree of vacuum detected by the degree of vacuum sensor. Submerging the first end of the suction transport pipe in the water of the sand basin and connecting the second end of the suction transport pipe to the solid-liquid recovery tank;
Connecting an open air pipe to the suction transport pipe at a position above the highest water level of the sand basin;
Depressurizing the inside of the solid-liquid recovery tank and the suction transport pipe,
Closing the air release valve provided in the air release pipe and sucking the sediment deposited in the sand basin as a solid-liquid mixture with water into the suction transport pipe,
When the water level rises above the connection part of the atmosphere release pipe, the atmosphere release valve is opened to open the connection part with the atmosphere release pipe to the atmosphere, and a water column for transportation is provided above the connection part. Forming,
Due to the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank, the transport water column is transported to the solid-liquid recovery tank while sucking the atmosphere through the open air pipe,
Close the atmosphere release valve immediately before the entire water column for transportation enters the solid-liquid recovery tank,
A sand transporting method characterized by repeating the formation and transportation of the water column for transportation by repeatedly opening and closing the air release valve. Submerging the first end of the suction transport pipe in the water of the sand basin and connecting the second end of the suction transport pipe to the solid-liquid recovery tank;
Connecting an open air pipe to the suction transport pipe at a position above the highest water level of the sand basin;
Connecting an air injection pipe to the suction transport pipe in the water of the sand basin;
Depressurizing the inside of the solid-liquid recovery tank and the suction transport pipe,
The air release valve provided in the air release pipe and the air injection valve provided in the air injection pipe are closed, and the sediment deposited in the sand basin is sucked into the suction transport pipe together with water as a solid-liquid mixture,
When the water level rises above the water level of the sand basin, the air injection valve is opened to inject air from the air transfer device into the suction transport pipe and above the connection with the air injection pipe The solid-liquid mixture of
Opening the atmosphere release valve and closing the air injection valve to open the connection portion with the atmosphere release pipe to the atmosphere to form a transport water column above the connection portion with the atmosphere release pipe,
Due to the difference between the atmospheric pressure acting on the transport water column and the degree of vacuum of the solid-liquid recovery tank, the transport water column is transported to the solid-liquid recovery tank while sucking the atmosphere through the open air pipe,
Close the atmosphere release valve immediately before the entire water column for transportation enters the solid-liquid recovery tank,
A sand transporting method characterized by repeating the formation and transportation of the water column for transportation by repeatedly opening and closing the air release valve and the air injection valve.   From the solid-liquid recovery tank to the suction transport valve in a state where the suction transport valve provided between the connection portion of the suction transport pipe with the atmosphere release pipe and the second end is closed at the time of initial startup The pressure is reduced to a predetermined degree of vacuum, and when the inside of the solid-liquid recovery tank reaches the predetermined degree of vacuum, the suction transport valve is opened, and the sediment deposited in the sand settling basin is solid-liquid mixed with water. 11. The sand transporting method according to claim 9, wherein suction is performed as a body into the suction transport pipe.   Injecting water from a water injection nozzle disposed in the vicinity of the first end so as to suck the sand and water as a solid-liquid mixture from the opening of the first end of the suction transport pipe, The sand transporting method according to claim 9 or 10, wherein sand is collected in the vicinity of the opening at the first end of the suction transport pipe. Detecting the degree of vacuum in the suction transport pipe by a vacuum degree sensor provided in the suction transport pipe,
The method of transporting sand transport according to claim 9 or 10, wherein the detected degree of vacuum is monitored to determine the number of transported water columns and / or whether the transport of water columns is normally performed. .

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