GB2103099A

GB2103099A - Treating slurry

Info

Publication number: GB2103099A
Application number: GB08126883A
Authority: GB
Inventors: Yoshiaki Togawa; Yoshio Taguchi
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-02-18
Filing date: 1981-09-04
Publication date: 1983-02-16
Also published as: JPS57137517A; NL8104072A; KR830007979A

Abstract

Apparatus for treating slurry comprises a pump 4 for sucking up the slurry, a slurry discharging passage 6 and a driving device 5 for driving the pump. Cement and setting agent for solidifying the slurry are fed into the slurry passing into the pump via lines 7 and 8, the feed rates of the cement and agent being controlled in accordance with the concentration of the slurry. The feed rates are controlled by a sensor which detects a change in the load on the driving device. <IMAGE>

Description

SPECIFICATION System for treating slurry The present invention relates to a solidifying system of slurry or slurry mud which includes a large quantity of water, and more particularly to a process for improving the slurry or slurry mud such as mud in the waterside of lakes, swamps, or discharged mud from underground constructions, so as to increase compressive strength of the mud to a proper value.

Since the slurry which is picked up or dredged from the waterside of bottom of the sea, rivers, lakes and swamps includes a large quantity of water, it takes a long period of time to set or solidify the slurry by dehydration. In order to give sufficient compressive strength to slurry, a special machine and treatment agent are required.

However, heretofore, it was difficult to treat slurry including a large amount of water to provide it with uniform compressive strength.

An object of the present invention is to provide a system for improving the slurry whereby a uniform compressive strength may be obtained by mixing an improving agent in the slurry.

According to the present invention, there is provided a system for treating slurry comprising an inlet passage for introducing said slurry, a pump for sucking up said slurry, a discharging passage for said slurry, a driving device for driving said pump, means for injecting a setting agent and cement into the passage consisting of said inlet passage and discharging passage, means for controlling the feed rates of said agent and cement to said passage.

These and other objects and features of the present invention will become more fully apparent from the following description with reference to the accompanying drawings, in which: Fig. 1 is a sectional view showing an apparatus for the method of the present invention; Fig. 2 is a schematic view showing a supply and control apparatus of an improving agent for the slurry, a part of which is broken away; and Fig. 3 is a schematic view showing another embodiment of the present invention.

Referring to Fig. 1, numeral 1 designates slurry or slurry mud to be dredged or discharged in a specific area. A discharging device 2 is submerged into the slurry mud 1. The discharging device 2 comprises a bell-mouthed inlet 3, a centrifugal pump 4 driven by a motor 5, and a discharging pipe 6 connected to the centrifugal pump 4. An injection pipe 7 for an improving agent and an injection pipe 8 for the aggregate such as sand are connected to the inlet 3 to be communicated with the inside thereof. The slurry mud is sucked up by the centrifugal pump 4 which is operated by the motor 5 and discharged into a proper container or area (not shown) through the discharging pipe 6.

As shown in Fig. 2, the injection pipe 7 is connected to a supply device of the improving agent through a control valve 1 The supply device comprises a cement silo 12, conveyors 1 3 and 14, a charge hopper 1 5, a water tank 16, a tank for a setting agent 17, gauges 18, 19 and 20, a slurry mixer 21, an agitator 22 and a feed pump 23. The cement stored in the cement silo 1 2 is transferred to the charge hopper 1 5 by the conveyors 1 3 and 14. The water fed from the water tank 1 6 is measured by the gauge 18. The cement from the charge hopper 1 5 is measured by the gauge 1 9 and the setting agent from the tank 1 7 is measured by the gauge 20.The properly measured water, cement and agent are poured into the slurry mixer 21 for forming slurry of the improving agent. The slurry of the improving agent is stored in the agitator 22. Then, the slurry is fed to the discharging device 2 through the pump 23 and controlled by the control valve 11 in proportion to the quantity of slurry mud which is sucked up by the centrifugal pump 4.

The setting or solidifying agent to be used together with cement. The agent is a water soluble agent which consists of metallic compound such as sodium carbonate (10.5 weight percent), sodium chloride (16.2), potassium carbonate (11.7), ferric chloride (6.4), aluminum chloride (4.1), magnesium chloride (13.8), potassium chloride (25.5), and calcium chloride (5.3). The mixing ratio of the agent to the cement is about 10% (weight percent).

On the other hand, a proper quantity of aggregate such as sand is fed to the discharging device 2 through the injection pipe 8 by a proper supply device.

According to the concentration of the slurry mud which is sucked up by the centrifugal pump 4, feed rates of the agent and aggregate are automatically controlled. For this purpose, a detecting sensor is connected to the centrifugal pump 4 or an engine for driving the pump 4 for detecting the variation of the load on the pump caused by the concentration.

According to the concentration of the introduced slurry, the load on the pump changes.

A governor, which is provided in the pump driving device, acts to keep the rotation speed of pump 4 constant, if the load changes. The sensor detects the change of the load to produce a signal in proportion to the concentration of slurry. The signal is applied to the control valve 11 through a controller 26. Therefore, the valve is automatically opened or shut to control the quantity of injection of the agent, The supplied agent is mixed with slurry in the inlet 3, and further in centrifugal pump 4 and discharging pipe 6 and discharged into the treatment area. Thus, the slurry is solidified by the action of the improving agent as it is deposited.

Fig. 3 shows another embodiment of the present invention. this embodiment is suitable for a device for treating a large quantity of slurry in dredging. Numeral 31 designates a hull of a pump type dredger. The hull is provided with an internal combustion engine 32, a centrifugal pump 33 driven by the engine 32, suction pipes 34, 35 and a discharging pipe 36 of the centrifugal pump 33, a cutter 37, and a motor 38 for driving the cutter 37.

The bed of the river, lake, etc is excavated by the cutter 37 which is rotated by the motor 38 so that sediment such as sand, soil, industrial waste and others are sucked up by the centrifugal pump 33 through suction pipes 34 and 35. Then, the slurry is transferred to the reclaimed land 40 through the discharging pipe 36. The supply device of the improving agent shown in Fig. 2 is connected to a part of the suction pipe 35.

Further, similarly to the previous embodiment, the supply of the improving agent is automatically controlled according to the concentration of the slurry which is sucked up by the centrifugal pump 33. For that purpose, a sensor 41 and a governor 42 are provided in the engine 32 to detect the change of the load which is caused by the concentration of siurry.

When the load of the engine changes according to the concentration of slurry, the governor 42 acts to keep the rotation of the centrifugal pump 33 at a predetermined speed. The change of the load is detected by the sensor 41 and a signal is applied to the controller 26 of Fig. 2. Then, the signal in proportion to the concentration is applied from the controller 26 to the control valve 11.

Therefore, as described hereinbefore, the valve 11 is automatically opened or shut to control the quantity of injection of the agent. The supplied agent is mixed with the slurry in the centrifugal pump 33 and discharging pipe 36. The slurry is deposited and solidified by the action of the agent.

In accordance with the present invention, since an improving agent for solidifying the slurry is mixed in the process of suction of slurry, no special machine is necessary. Further, the agent is sufficiently and uniformly mixed with slurry.

Therefore, slurry may be uniformly set or solidified in a short period of time.

Claims

1. A system for treating slurry comprising an inlet passage for introducing said slurry, a pump for sucking up said slurry, a discharging passage for said slurry, a driving device for driving said pump, means for injecting a setting agent and cement into the passage consisting of said inlet passage and discharging passage, means for controlling the feed rates of said agent and cement to said passage.

2. A system for treating slurry according to claim 1 wherein said pump and driving device are submerged in the slurry.

3. A system for treating slurry according to claim 1 wherein said pump and driving device are mounted on a hull.

4. A system for treating slurry according to claim 1, wherein said means for controlling the feed rates includes a sensor for detecting the load on said driving device for generating a control signal in response to said load.

5. A system for treating slurry, substantially as hereinbefore described with reference to, and as illustrated in, Figure 1 or Figures 1 and 2 or Figure 3 of the accompanying drawings.