JP5789286B2 - Grout pumping device and method - Google Patents

Description

  The present invention provides a pulsation absorbing portion between or both of a piston-type multi-cylinder grout pump and a stretchable injection hose provided with a discharge port for each cylinder used in the ground injection construction method. The present invention relates to a grout pumping device and method for reducing pulsation by passing through a pulsation absorbing section.

  In general, a fluid grout used for the ground injection method employs a method of pressurizing and pumping from a discharge port using a pump. There are many types of grout pumps that have different pump structures depending on the properties of the grout. Among these, the present invention belongs to a piston type (including a plunger type).

  Among the grouts to be used, in the chemical grout where the A liquid (mainly water glass is mainly used) and the B liquid (hardening agent) are discharged from the discharge ports and then mixed and mixed, the four-cylinder dual system (two discharge ports are provided). ) Plunger pump (hereinafter referred to as piston type) is often used. This pump is a mechanism in which a cylinder part (hereinafter referred to as a cylinder) is a piston type and extracts a component in only one direction of a crank that performs a circular motion and mechanically reciprocates the piston. Then, an operation of bringing the piston into close contact with the inner surface of the cylinder is performed, and one surface of the piston performs discharge, and the other surface performs a suction action, and a continuous discharge operation is performed by a reciprocating motion.

  Of these, the plunger is a single action that is inserted into a part of the cylinder, discharges the grout during the forward movement, and sucks the grout during the backward movement.

  And when used for chemical grout (A, B liquid type), two pumps are combined into one unit, the valve chamber is completely separated into two chambers, and the left and right cylinders discharge two liquids separately It has become.

  For this reason, a so-called four-cylinder dual pump is provided in which one discharge port (A liquid) is provided with two cylinders and the other two cylinders are provided with one discharge port (B liquid).

This pump is characterized by eliminating grout pulsation by performing suction and discharge simultaneously with two cylinders as one set. The pulsation here means that the liquid is fed so as to pulsate by periodically breaking the liquid feeding operation. In order to reduce such pulsation, one air chamber is attached to two cylinders. The air chamber is not so large, and the body volume is about 400 cm ³ or less.

  In addition, as a technique using the pulsation of grout by these pumps, for example, the disclosed technique of Patent Document 1 is proposed. According to the technique disclosed in Patent Document 1, a conventional two-cylinder grout that keeps a constant discharge amount (injection speed) is used, and a control device is attached to the pump to adjust the rotational speed of the pump. As a result, it is possible to realize the chemical solution injection in which the injection speed or the injection pressure is dynamically (forced) changed.

  When used for the main purpose of this injection method (two-component, separately pumped into liquid A and liquid B), before the injection tube via two injection hoses in a four-cylinder dual system, or Inject the chemical solution made by mixing the mixture from the tip into the ground.

  However, the disclosed technique of Patent Document 1 is an original one in which an expensive control panel is attached to a pump with a constant discharge, and the pump itself is a conventional two-cylinder one-unit type, so the number of pumps can be reduced, It cannot be said that this is an injection method that solves the problem that it cannot cope with injection of a low discharge amount.

JP 2005-330805 A

Hiroshi Onishi "New Edition, Illustrated Grout Handbook" Latteis Co., Ltd., p200-p219 July 4, 1972

As described above, since the basic principle of the conventional pump is a two-cylinder one-line system, there are the following problems from the points to be improved and workability.
1) Since it is one discharge port with two cylinders, many pumps are required.
2) Since two cylinders are used as one discharge port, the grout discharge amount is a sum, and it is difficult to reduce the discharge amount at a high pressure (for example, 2 to 4 l / min) because of the structure of the pump.

  Among the above, 2) is considered a difficult point that cannot be solved in construction.

  However, when a two-component grout is provided for each cylinder with the current pump, the pulsation (the fluctuation range of the flow amount is large) is large. In other words, there was a problem that the gel time changed extremely and could not be used practically.

  Non-Patent Document 1 discloses a piston type and a plunger type as examples of the grout pump, but does not specifically disclose a technique for reducing pulsation.

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the purpose of the present invention is to reduce pulsation by allowing the grout to pass through the pump, the injection hose and the pulsation absorbing part, It is an object of the present invention to provide a grout pumping apparatus and method capable of realizing stable ground injection of grout.

  In the conventional technique described above, providing a discharge port for each cylinder with a piston pump has a very large grouting pulsation and cannot be used as it is. Therefore, in the present invention, the pump and the grout pressure feeding method that avoids the pulsation caused by providing the discharge port for each cylinder to the practical range have been studied.

  In other words, the present invention provides a pump or piston for pumping by providing a stretchable or non-stretchable pulsation absorbing portion between a soft injection hose extending from a discharge port including a pump body to an injection tube having a certain length. This is a method of reducing the pulsation within a practical range in the process in which the grout passes through the pulsation absorbing part in the pump or the pulsation absorbing part between the injection hoses.

The grout pumping device according to claim 1 is a grout pumping device for pumping grout into the ground via an injection tube, and is provided for each of the plurality of pistons that can reciprocate according to the rotational drive of the drive unit. In response to the reciprocating motion of the stored piston, grout is sucked into and discharged from the inside, and the grout discharged from the cylinder is provided for each of the cylinders. A discharge port and an injection hose for guiding the grout discharged from the discharge port to the injection pipe, the injection hose being 20 m or more, between the cylinder and the discharge port, and between the injection hoses Content for absorbing pulsation by adjusting the amount of grout discharged into the injection pipe, in a container shape in which the grout can temporarily enter or stay in any one or more places Wherein the but has pulsation absorbing portion is provided at 500 cm ³ or more

The grout pumping device according to claim 2 of the present invention is characterized in that, in the invention according to claim 1, the pulsation absorbing portion is an air chamber provided for each cylinder.

The grout pumping device according to claim 3 of the present invention is the invention according to claim 1, wherein the pulsation absorbing portion is provided between the injection hoses, and is a stretchable stretchable member, a non-stretchable non-stretchable member, the stretchable member, It is comprised by either of the said non-expandable members.

The grout pumping method according to claim 4 of the present application uses the grout pumping device according to any one of claims 1 to 3 to temporarily infiltrate or retain the grout in the pulsation absorbing portion, and to perform the injection. It adjusts the amount of grout discharged to the pipe and absorbs the pulsation while pumping it.

  According to the present invention having the above-described configuration, grouting can be reduced by passing through the pump, the injection hose and the pulsation absorbing portion, and stable ground injection of grouting can be realized.

It is a front view of the grout pumping device to which the present invention is applied. It is a side view of a grout pumping device to which the present invention is applied. It is a figure which shows the pulsation absorption part comprised by the bellows shape which has a stretching property.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a grout pumping apparatus to which the present invention is applied will be described in detail with reference to the drawings.

  The grout pumped by the grout pumping apparatus to which the present invention is applied is composed of one liquid, or two liquids consisting of liquid A (mainly water glass) and liquid B (curing agent), and is a piston type used for the injection method. In the case of a cylindrical pump, a four-cylinder dual-series system is generally used when pumping grout.

  In this case, the reciprocating motion of the piston is alternately performed with two cylinders as one set. That is, the grout is discharged by the forward movement, and the grout is sucked by the backward movement. Then, the grout is uniformly discharged from one discharge port by combining these two cylinders. This method is based on the principle that the grout is pumped from two discharge ports with four cylinders.

  Therefore, when the grout is two-part (divided into Part A and Part B), it is injected through one injection pipe, and when it is one-part, it is injected through two injection pipes.

  On the other hand, according to the present invention, by using a pump provided with a discharge port for each cylinder, the number of pumps to be used can be halved, and a lower discharge amount (2 to 4 l / min) is injected. Is possible.

  In particular, a more expensive pump (hydraulic type or the like) is required to provide a function that can accurately maintain a low discharge amount and that can be injected at a high pressure (0.5 to 5 MPa).

  Therefore, in the present invention, a discharge port is provided for each cylinder by remodeling a versatile pump currently used.

  FIG. 1 is a front view of a grout pumping apparatus 30 to which the present invention is applied, and FIG. 2 is a side view thereof. The grout pumping device 30 includes a pump body 1, a drive unit 2 mounted in the pump body 1, four cylinders 3 a to 3 d provided in the lower part of the drive unit 2, Four pistons 4 a to 4 d provided therein, four connection pipes 6 a to 6 d connected to the cylinder 3, ball valves 5 a to 5 d disposed inside the connection pipe 6, and Suction ports 7a to 7d and discharge ports 9a to 9d formed by opening a part of the connection tubes 6a to 6d, pulsation absorbing portions 8a to 8d extending from the connection tubes 6a to 6d, and discharge ports And injection hoses 10a to 10d connected to 9a to 9d.

  This drive part 2 is comprised from what is called a crankshaft, and a shaft is bend | folded sequentially and is comprised. Each axis of the two pistons 4a and 4b is connected to the drive unit 2 in one set, and each axis of the two pistons 4c and 4b is connected in one set. The two pistons 4 connected in one set are provided at different bending positions of the crankshaft constituting the drive unit 2. For this reason, when the rotational power is transmitted to the drive unit 2, the positions of the two pistons 4 connected in one set during the vertical movement are different from each other as shown in FIG. Further, the two pistons 4 connected in one set reciprocate alternately.

  The cylinders 3 a to 3 d accommodate pistons 4 a to 4 d that move up and down based on the rotational drive of the drive unit 2. Lower portions of the cylindrical bodies 3a to 3d communicate with connecting pipes 6a to 6d, respectively. The cylinders 3a to 3d are supplied with grout from the connection pipes 6a to 6d, or send the grout to the connection pipes 6a to 6d.

  The injection hoses 10a to 10d are made of a stretchable material and have a length of 20 m or more.

  The pulsation absorption unit 8 includes a pulsation absorption unit 8A or a pulsation absorption unit 8B having different functions. The pulsation absorbing portion 8A is mainly called a so-called air chamber connected to the connecting pipe 6, and is composed of a cylindrical metal member closed at the top. Depending on the inner volume of the air chamber, the air chamber may be provided outside the discharge port 9 when it cannot be attached to the pump body.

  The function of the air chamber as the pulsation absorbing portion 8A is that when the grout filled in the cylinder is pushed out (discharged) by the piston 4 in a pressurized state, the pulsation absorbing portion partially compresses the air in the air chamber. Invade in 8. Next, when the piston 4 is pulled (inhalation), the pressure is reduced, and the grout in the air chamber is discharged to return to atmospheric pressure. As the pulsation absorbing portion 8 intrudes into the air chamber and decreases in discharge, the amount of grouting is adjusted to absorb pulsation.

  In addition, since the conventional air chamber is a two-cylinder type and discharge and suction are performed simultaneously in one air chamber, grout press-fitting (air compression) is repeated in a state that is almost always inside the air chamber. Since the effect as the pulsation absorbing portion 8 referred to in the invention cannot be exhibited so much, it is distinguished from the pulsation absorbing portion 8 referred to in the present invention.

  The pulsation absorbing portion 8B has a structure in which a stretchable elastic member such as soft rubber or plastic or a non-stretchable member such as hard rubber, plastic and metal, and a combination of a stretchable member and a non-stretchable member. Although it may be, it is preferably an elastic member.

  The pulsation absorbing portion 8B has a container shape including an inlet from the pump side and an outlet to the injection tube side, and the shape and structure thereof are not particularly limited, but are configured in a bellows shape including an elastic member. It is desirable.

  The pulsation absorbing portion 8B is a container having a larger cross-sectional area than the injection hose 10 provided between the injection hoses from the discharge port 9 from the cylindrical body 3 to the injection pipe 11.

  The function of the pulsation absorbing portion 8B is such that when a pulsated grout delivered from the discharge port of each cylinder flows into the container-like pulsation absorbing portion 8B having a larger cross-sectional area than the injection hose 10 through the injection hose 10, the flow velocity increases. It is decelerated and partly turbulent, and the pulsation is absorbed.

  That is, the pulsation absorbing portion 8 may be configured by any one of a telescopic member that is stretchable, a non-stretchable member that is not stretchable, a stretchable member, and a non-stretchable member.

  In the present invention, the phenomenon in which the flow velocity is greatly decelerated in the container and becomes a staying state and absorbs pulsation is simply referred to as staying.

The pulsation absorbing portion 8 is preferably configured with an internal volume of 500 cm ³ or more. Since the internal volume of the air chamber attached to the conventional plunger type pump body is less than 500 cm ³ , the internal volume of the pulsation absorbing portion 8 is configured with a size larger than this.

  The pulsation absorption unit 8 may reflect the configuration of either one or both of the pulsation absorption unit A and the pulsation absorption unit B.

  In the present invention, the above-described pulsation absorbing portion 8A and pulsation absorbing portion 8B are used alone or in combination so that the time-curable material such as grout is between the pulsation absorbing portion 8, the injection hose 10, and the injection hose in the pump. By passing through the pulsation absorbing section, a practical injection speed (discharge flow rate) can be obtained by absorbing the pulsation.

  The determination of the pulsation absorption rate in the present invention is based on the difference L3 between the minimum length L1 (distance) and the maximum length (L2) when the grout is discharged horizontally from the discharge port 9 at a height of 1 m. A value obtained by dividing (= L2−L1) by L2 is defined as% obtained by subtracting from 100. Specifically, pulsation absorption rate (%) = 100 − [(L2−L1) / L2 × 100].

  The pulsation absorption rate of 60% or more was set as a range defined in the present invention as a practical range. The pulsation absorption rate is determined according to the length of the injection hose 10, the type of member of the pulsation absorption portion 8 (existence of stretchability, etc.) and the size of the inner volume thereof.

As shown in FIG. 1, the grout pumped by the grout pumping method to which the present invention is applied is provided for each cylinder 3 and is provided between the pulsation absorbing portion 8 connected to the connecting pipe 6 or the injection hose 10. It reaches the final injection tube 11 through the pulsation absorbing portion 8A. Of these, the pulsation absorbing portion 8B provided between the injection hoses 10 may have any shape and structure as long as the internal volume is 500 cm ³ or more. It is desirable that the pulsation absorbing portion 8 ′ is configured in a vertical position as shown in FIG. Thereby, it can connect so that the lower side of pulsation absorption part 8 'may become the pump side, and an upper side may become the injection tube 11 side, and it becomes possible to absorb a pulsation efficiently.

  The injection hose used in the present invention is a material that can be specifically rolled with an elastic member.

  In addition, since the grout pressure feeding device 30 to which the present invention is applied is provided with a discharge port 9 for each cylinder 3, in the case of a so-called four-tube quadruple plunger pump, the discharge amount per cylinder is At 2 to 10 liters per minute, one rotation of the crank constituting the drive unit 2 (total of suction and discharge) is about 0.2 to 1 second.

  The grout used in the grout pressure feeding method to which the present invention is applied includes a chemical liquid system (chemical grout) and a non-chemical liquid system.

  This chemical solution system is mainly a water glass system, and an alkaline system in which a hardener is added to water glass and gelled in an alkaline region, and an acidic hardener (sulfuric acid, phosphoric acid, etc.) is added to water glass, There is a non-alkali system that gels in the acidic-acidic region. Furthermore, a suspension as a hardening developing material such as cement can be added as a hardening agent.

For non-chemical liquid systems, cement, cement and slag, hardening material particles such as slag and lime were added with a suspension of ordinary cement (brane value of about 3000 cm ³ / g) or more, and an adhesive (such as bentonite). Can be used as a grout.

  In the grout pressure feeding method to which the present invention is applied, when a four-cylinder quadruple system is used, a single-flute grout has one cylinder / single-unit four-injection pipe, and a two-liquid type (liquid A, liquid B) has two cylinders / two-series. It can be injected into two injection pipes simultaneously by the formula, and can be constructed with half the number of conventional pumps. Furthermore, the construction can be performed with a discharge amount that is 1/2 that of the conventional one.

  In the present invention, it is desirable to properly use the pulsation absorption rate depending on whether the grout is one-part or two-part. That is, even if some pulsation is present in the one-part type, it can be sufficiently put into practical use, and the pulsation absorption rate may be 60% or more. On the other hand, it is desirable that the pulsation absorption rate is 90% or more in order to reduce the difference in gel time when mixing the liquid A (water glass) and the liquid B (curing agent) as close as possible to reduce the difference in gel time. .

  Hereinafter, the present invention will be described in more detail with reference to examples.

  The pump used in the experiment is a four-tube quadruple plunger pump (NPOT-40TN manufactured by Nippon Construction Machinery Co., Ltd.) as shown in FIG. The pulsation absorbing portion 8A is an air chamber type and a pulsation absorbing portion 8B configured to have a stretchable bellows shape.

  Further, the discharge port has an inner diameter of 9.4 mm, an inner diameter of the injection hose of 12 mm, and an inner diameter of the discharge port of the injection hose of 7.2 mm.

(Experiment 1)
The experiment was carried out by the above-described method for determining the pulsation absorption rate, and Table 1 shows the measured values and pulsation absorption rate obtained under various conditions using water (tap water) as a substitute for the grout.

  The number of rotations of the pump (total of suction and discharge) is 0.72 seconds at a discharge amount of 5 l / min and 0.33 seconds at 8.7 l.

As shown in Table 1, in Comparative Example 1 without the injection hose 10 and the pulsation absorbing portion 8, since the pump is a single cylinder / single line type, liquid is produced at the time of discharge, but no liquid is produced at the time of inhalation. If an air chamber inner volume of 400, 500, or 800 cm ³ (Comparative Examples 2 to 4) is attached as the pulsation absorbing portion 8A, it is discharged even during inhalation, but the pulsation absorption rate is 48.6% or less, which is not suitable for practical use. It turns out that.

On the other hand, when the injection hose 10 is 5 m, when the internal volume of the pulsation absorbing portion 8 is 500 to 800 cm ³ (Comparative Examples 9 and 10), the pulsation absorption rate is 51% or less, which may be unsuitable for practical use. confirmed.

Further, the injection hose 10 is extended to 20 m, the pulsation absorption part 8A is an air chamber (none and internal volume 400 cm ³ ) (Comparative Examples 5 and 6), and the bellows type of the pulsation absorption part 8B (internal volume 400 cm ³ : Comparative Example 7). ) Is unsuitable for practical use in which the pulsation absorption rate is 40% or less.

On the other hand, when the internal volume of the pulsation absorbing portion 8A and the pulsation absorbing portion 8B is increased to 500 cm ³ or more (Invention Examples 1, 2, 3, 4, 5), the pulsation absorption rate is increased to 68.6% or more. It was confirmed that the pulsation was reduced to a practical range.

  Furthermore, when the injection hose 10 was 40 m, it turned out that a pulsation absorption rate can be raised more (invention example 9).

  Further, when the present invention example 1 when the pump discharge rate is 8.7 l / min and the present invention example 10 when the pump discharge rate is 3.4 l / min are compared, the present invention example 1 is 68.6%, Invention Example 10 was 67.6%, almost the same. For this reason, it turned out that it can apply in the practical range (about 2-10 l / min) of pump discharge amount.

From the above experimental results, according to the present invention, when the injection hose 10 is 20 m or more and the internal volume of the pulsation absorbing portion 8 is 500 cm ³ or more, the pulsation absorption rate is 60% or more even in the case of one single cylinder type. It was found that it was within a practical range.

(Experiment 2)
Here, the change of the gel time by the difference in the pulsation of the two-liquid instant connection type grout was investigated on the ground using the 4 cylinder 4 series piston type (plunger type) pump shown in FIG.

  In the experiment, the liquid A was passed through the cylinder 3a and the liquid B was passed through the cylinder 3b, and joined at the tip of the injection hose 10 under the conditions of Comparative Example 6 and Comparative Example 7, Invention Example 1 and Invention Example 3 in Table 1. Table 2 shows the results of measuring the gel time of the mixed grout 6 times every 3 minutes.

  The grout used in the experiment is a water glass type solution type, liquid A (27.5 l of No. 3 water glass, balance is water, 100 l in total), liquid B (2.7 l of 75% dilute sulfuric acid, 2.0 kg of sulfuric acid clay) When the experiment was carried out indoors with the remainder being water, totaling 100 l), the gel time was 10 seconds (Invention Example 12).

  According to Table 2, Comparative Example 13 and Comparative Example 14 correspond to the conditions of Comparative Examples 6 and 7, and the pulsation is large and the pulsation absorption rate is 38.7 to 39.6%. It changed greatly as 62 seconds. This is because the gel time is shortened when the mixing ratio of the B liquid with respect to the A liquid is large, and conversely, the gel time becomes long when the mixing ratio of the B liquid is small. As it turned out to be unsuitable for practical use. Usually, the quick setting grout has a gel time of 20 seconds or less.

  On the other hand, in Examples 13 and 14 of the present invention, since the pulsation is small and the pulsation absorption rate is 88.3 to 91.1%, the change in gel time is 7 to 14 seconds as compared to 10 seconds for mixing the indoor equal amount. It was confirmed that it was a practically usable range as a flashing grout.

DESCRIPTION OF SYMBOLS 1 Pump main body 2 Drive part 3 Cylindrical body 4 Piston 5 Ball valve 6 Connection pipe 7 Suction port 8 Pulsation absorption part 9 Discharge port 10 Injection hose 11 Injection pipe 30 Grout pressure feeder

Claims (4)

In a grout pumping device that pumps grout into the ground via an injection tube,
A plurality of pistons capable of reciprocating according to the rotational drive of the drive unit;
A plurality of cylinders that are provided for each of the pistons, and inject grout into the pistons according to the reciprocating motion of the stored pistons, and discharge the grouts;
A discharge port that is provided for each cylinder and discharges grout discharged from the cylinder,
An injection hose for guiding the grout discharged from the discharge port to the injection pipe,
The injection hose is 20 m or more,
It is made into the container shape which can make the said grout enter | penetrate or stagnate temporarily in any one or more places between the said cylinder from a discharge port, and between the said injection | pouring hoses, and discharge of the grout to the said injection pipe A pulsation absorbing part having an internal volume of 500 cm ³ or more for adjusting the amount to absorb pulsation is provided.
Grout pumping device according to claim. The grout pumping device according to claim 1 , wherein the pulsation absorbing portion is an air chamber provided for each cylindrical body. The pulsation absorber is provided between the injection hose, extendable elastic member, elastic non unstretchable member, characterized in that it is constituted by the elastic member and the non-stretchable member, either one of Item 2. A grout pumping device according to item 1 . Using the grout pumping device according to any one of claims 1 to 3 , the grout is temporarily infiltrated or retained in the pulsation absorbing portion, and the amount of grout discharged to the injection pipe is adjusted. A grout pumping method characterized by pumping a pulsation while absorbing it.

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