CN1072232A - Riverbed current automatic desilting principle and device thereof - Google Patents

Abstract

Present technique is used to have the river dredging and the dredging waterway of mobile current.Belong to water conservancy construction and maintenance equipment.The energy that utilizes river waterflow to flow, by the effect that collapsible tube improves flow rate of water flow and controlling organization, high-velocity flow is concentrated on needs the desilting position, increases river silt particle source, thereby increases the river sand content, and silt particle is taken away, and realizes the purpose of desilting.

This device can install the Accrete clearing device (as accompanying drawing one) of energy ascending, descending in two oceangoing ship amidships additional; Can install energy ascending, descending Accrete clearing device (as accompanying drawing one) in existing hull bottom (centre or both sides) additional; Also can make Accrete clearing device and ship one, energy sedimentation, the dredger that floats.

Description

Riverbed current automatic desilting principle and device thereof

Present technique is used to have the river dredging and the dredging waterway of circulating water.Belong to water conservancy construction and maintenance equipment.

Through retrieving and consult interrelated data, find the technology and equipment identical as yet with present technique in Yichang City's patented technology office.

Flood erosion, soil erosion, generally deposit in the downstream, and raise the river bed, and the handling capacity of flood is constantly reducing, and one meets waterfall rain, flood, and impeded drainage causes floods in various degree more and more many.

For many years, in main control measures of the upstream and downstream in river and situation:

In the upstream, be to build reservoir on the one hand, water conservation and silt particle make and let out under the flood evenly, reduce because of flood and concentrate the disaster that causes, and retain silt particle, temporarily slow down the alluvial in downstream.Quicken greening on the other hand, do water and soil conservation well, reduce the downstream river course alluvial.

The hydraulic engineering of upstream, mostly be support and attention that comprehensive (flood control, generating, irrigation, shipping, breed) economic benefit obvious (calculating in the recent period) obtains each side easily, invest solution easily, so the hydraulic engineering of upstream progress is very fast, better.For example the upper reaches of the Yellow River have successively been built up Qingtongxia, salt pan gorge, have been listed as large hydraulic engineerings such as tame gorge, Ba Panxia, Long Yangxia.The Changjiang river middle and upper reaches have: reflecting of the Gong Zui in the boat Jiangkou in Han River, Huanglong beach, Dadu River, Ming River is elegant curved, and hydraulic engineering such as is crossed in the Wujiang River on the Wujiang River; Plentiful, hundred mountains in Song Hua River; Bigization in Hongsuihe River, Xin Fengjiang, Liu Xi river etc..And also have under construction and planning many large hydraulic engineerings.These project on flood control prevent to deposit and have played very big effect.But the ability of their water conservation is limited, particularly emphasizes in recent years to account for less to flood the farmland, and general reservoir capacity is long-pending less than normal, and many engineerings do not have the effect of flood retention, and effect is just littler to a torrential rain brings floods in the downstream.Can only play the effect of postponement to blocking sand, anti-silt.

Greening has been measure, but effect is slow, and flood and heavy rain are also acted on not quite, so greening is long-range chronic engineering, effect also is limited.

In the downstream, main control measures has, and dykes and dams are intercepted, and flood-diversion area etc. is set up in the cleaning river course.

It is after liberation that dykes and dams are intercepted, decades, and at lower reache, the major measure of flood control and disaster relief.Will spend sizable investment every year, improves the dykes and dams of reinforcing the hazardous location.To guaranteeing the people life property safety, assurance national economy is not suffered a loss and has been played decisive role.

But, along with increasing of riverbank dykes and dams, because is constantly increasing bottom, alluvial riverbed.The basin is reduced, impeded drainage, the river course stops up, and drainability reduces, and brings bigger potential harm.

Downstream, the Yellow River, river bed have exceeded ground, two sides, and two sides have not had the river can flow into the Yellow River, in case run into the flood that can not resist, consequence is hardly imaginable.And this potential harm, increasing year by year.

THE LOWER YANGTZE VALLEY, though more quite a lot of than the Yellow River, many sections are also arranged, it is a lot of that flood period, river exceeded the town and country, two sides, and general the fraction of the year, tributary flood peaks such as main stream of the Yangtze and Han River, Xiang River mostly are and stagger, and relative risk is littler.In recent years, unusual weather conditions, as do, the tributary flood peak is met the downstream simultaneously, will cause great danger, the floods in the Changjiang river have every year, big floods can not be underestimated.

This year, Huaihe River, Taihu Lake flood were littler than 54 years, but water table ratio 54 years is high, and water level of tai hu long period behind flood slowly descends, and proves that all downstream siltation is serious, impeded drainage, and illustrating needs the urgency of administering.

Dangerous section has been set up the flood-diversion area in many rivers, gives up a chariot to save the marshal in case of necessity, and this is a unavoidable measure.Flood-diversion area, Huaihe River in this year, flood and plough 1,580,000 mu, the people life property loss is serious.

The control measures that downstream river is intercepted based on dykes and dams increases the weight of alluvial, and river surface is widened, and raise the river bed, and the flood potential hazard is more and more big, is a vicious circle.

The dredging waterway desilting can make current concentrate, and reduces width, reduces alluvial, and the draining smoothness reduces water level, is a measure that effects a permanent cure, and can make the dredging waterway operation, is in benign cycle.

Because engineering quantity is big, desilting regulation efficient is low, costly, and this useful measure can not be carried out on a large scale.See from newspaper, Tianjin is to the desilting in the Xinhe River, Yongding, and only 18 kilometers, last 4 years, expensive 3.7 hundred million yuan, just return to design section.

Only, great river, the desilting of downstream, great river are costed, be difficult to bear with regard to the economic capability of current country.And a desilting, there are not effective measures, how long keep not wanting the original state of also can becoming silted up back.

As seen the improvement of China's rivers, weak link is in the downstream, and flood damage is industrial or agricultural prosperity, densely populated downstream river, and it is also maximum to cause damage.River regulation, the cleaning alluvial is the good measure of administering downstream river, but has formed contradiction with the national economy ability.

Current automatic desilting device solves this contradiction and proposes, and it is the main equipment of regulation desilting, is to use less investment, the channel cleanout important means that takes effect rapidly, be to realize that party and state proposes to arouse the masses, large-scale building of water conservancy projects, the effective measures of the great task of acceleration river management.

Current common several dredge boats

1. grab dredger: be to adorn a clam-type loader aboard ship, from water, silt particle got hold of that shipment is transported, or silt particle picked up serve the bank;

2. shovel dredge boat: be, from water, silt particle scooped up that shipment is transported, or directly serves the bank aboard ship with a power shovel dress;

3. the dredge boat of wheel and bucket type: be on large-scale rotary disk periphery, many small-sized scraper bowls are when the garden dish rotates, below scraper bowl silt particle is scooped up from water, forward to when top and pour silt particle into defeated muddy road, transport shipping on the stream and walk, or use belt conveyer, be transported to the bank;

4. the dredge boat of air absorbing odour exhausting type: be to load onto the powerful slush pump of power aboard ship, muddy water is sucked up, output to other place through piping;

Also has other ... kind, but their general characteristic is:

1. powerful power is housed, and plant equipment consumes a large amount of power sources during work, and corresponding maintenance of equipment and maintenance facility;

2. for silt particle is transported, must be equipped with enough haulage devices, with the increase of haul distance, the corresponding increase of freight charges;

3. be in water, to drag for silt particle, band water transport silt particle, general work efficient is all lower;

4. equipment operation personnel selection is more, and the labour consumes also very big;

Utilize these equipment to carry out the dredging waterway desilting, the big power consumption of equipment investment is many, and the time is long, efficient is low, and is expensive quite big, is the main cause that current dredging waterway desilting work can not extensively be carried out.

Riverbed current automatic desilting principle of device

The energy that utilizes river waterflow to flow utilizes the characteristic that contains sand in the rivers water, increases the sand content of current, with current silt particle is taken away, and reaches the purpose of river regulation, reaches the purpose of removing alluvial,

Have rivers that flowing water flow is just arranged, mobile water is being contained lot of energy, and alluvial is that current cause, the fluidised form (speed and direction) that changes current utilizes his energy to carry out desilting, be water-control, energy develops nearby, is to be economy good method easily again.

Following surface analysis once, the flow energy utilization and the alluvial characteristic.

1. the source of silt particle how much, is sand content principal element in the river waterflow

Analyze the situation of silt content and change in flow with practical conditions.Yichang, the Changjiang river river sand content is, for many years average content 1.18kg/m ³, maximum for many years average sand content 1.47kg/m ³, minimum actual measurement sand content 0.009kg/m ³, maximum actual measurement sand content 10.5kg/m ³, the minimax measured value differs 1172 times, and average for many years and maximum measured value also differs 9 times.And flood and dry season flow velocity differ less comparatively speaking.The size of flow velocity depends primarily on stream gradient and falls, and Yichang is to the entrance of Changjiang River section, and Wusong mouth is zero, and general Yichang water level is many about 45 meters, the about ten thousand/nought point four of gradient.When flood period the Yichang water level about 58 meters, gradient has only 5/10000ths.The pass of flow velocity (V) and gradient (H) is $\mathrm{V\; \alpha }\sqrt{H}$ , increase by 1.25 times than general water level gradient flood period, and flow velocity only increases by 1.12 times.Change in flow is far smaller than the variation of silt content.

The Yellow River is from upstream to the downstream, and it is that the dragon dollar gorge is 0.8kg/m that average for many years sand content changes ³, the salt pan gorge is 2.94kg/m ³, the Qingtongxia is 5.8kg/m ³, and be about 30kg/m to the Sanmenxia Gorge ³, more than the Sanmenxia Gorge mountain area, plateau, the slope is bigger, and flow velocity is also big, and sand content is really little, and the Sanmenxia Gorge enters the region of no relief, and gradient is little, and flow velocity is also little, and sand content really is far longer than the upstream.Illustrate that also the river sand content depends primarily on the source of silt particle.The loess plateau of flowing through, the Yellow River makes river contain sand and rolls up.

Yichang, the Changjiang river, the Sanmenxia Gorge, the Yellow River is the starting point that the Changjiang river, the Yellow River flow to the Plain, the average for many years water yield of two places on average contains sand and average year sediment transport amount for many years for many years.

The average for many years sand content average year sediment transport amount of the address average year water yield

Yichang, the Changjiang river 4,500 hundred million m ³1.18kg/m ³5.36 hundred million tons

The Sanmenxia Gorge, the Yellow River 47,000,000,000 m ³30kg/m ³1,400,000,000 tons

All in the flat-bottomed land, flow velocity is more or less the same, and the sand content Sanmenxia Gorge is higher 25.4 times than Yichang, and the Sanmenxia Gorge, the Yellow River year water yield only is 1/10th of Yichang, the Changjiang river, and year sediment transport amount, the Sanmenxia Gorge is nearly three times of Yichang.

See from interrelated data, actual measurement maximum sand content in place, the Sanmenxia Gorge, the Yellow River is up to 511kg/m ³, the silt content of the Yellow River is surprising.

More than explanation, as long as effective measures are arranged, it is still not possible to increase the current sand content, and the potential number that can increase also is sizable.

With Yichang, the Changjiang river is example, and sand content is from long-time average annual value (1.18kg/m ³) be increased to maximum average value (1.47kg/m ³) increase by 1.3 hundred million tons of sediment transport amounts, be 1/4th of year sediment transport amount.If be increased to maximum measured value (10.5kg/m ³) increase by 42.3 hundred million tons of sediment transport amounts, be 8 times of year throughput rate.THE LOWER YANGTZE VALLEY has big tributary such as Han River, Xiang River to flow into again, and carrying capacity is bigger, silt particle may be taken to the quantity that the sea is gone, and is just more considerable,

2. utilize the energy of current, increase the silt content of river, silt particle is taken away the purpose that reaches river dredging.

The general flow velocity in the river in Plain is about 1～2M/S, and flow velocity is improved, and adjusts its direction, position, it is in impacts the best position of alluvial silt particle, just can dash silt particle rapidly, increases the silt content of current.

Utilize the purpose (as accompanying drawing four) that collapsible tube reaches increases flow velocity;

The energy balance formula of importing and exporting

$\frac{P_1}{r}+\frac{a_1{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="911105921\_DRIMG1.png,911105921\_DRIMG2.png"\; state="\{\{state\}\}">V</figure-callout>}}^2{}_1}{\mathrm{zg}}=\frac{P_2}{r}+\frac{a_2{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="911105921\_DRIMG1.png,911105921\_DRIMG2.png"\; state="\{\{state\}\}">V</figure-callout>}}^2{}_2}{\mathrm{2g}}{\mathrm{+\; H}}_r$

P1, P2 and V1 V2 are respectively the pressure and the flow velocity of import and outlet.Hr is the flow through losses of collapsible tube of current, comprises entry loss, shrinkage loss and linear loss.Improve condition for import with the garden arc, angle of throat reduces as far as possible, can make efficient more than 85～90%.

According to the continuous characteristic of current, V ₁W ₁=V ₂W ₂

V ₂=(W ₁)/(W ₂) V ₁W1 W2 be the import export section area the energy of import current, concentrate to be transformed into outlet speed energy.

The speed of outlet is bigger, and impact area is little, and impulse force increases, and muzzle velocity is little, and impact area increases, and impact force reduces, so select suitable muzzle velocity that enough impulse forces are promptly arranged, impact area is also not too little, and it is best to make it comprehensive benefit.For this reason, the ejection current are partly made and can be regulated discharge area, and are different and obtain the needs of effective muzzle velocity to adapt to inlet velocity.

Nozzle will be near being impacted the silt particle part, to reduce the submerge loss of current in water.

Flowing water energy is huge and is inexhaustible in the rivers, with it energy without cease, it is used in dredging waterway and the desilting will produce huge economic benefit, administers to move towards to circulate benignly and plays a role for rivers regulation and desilting make it.

3. the change streamflow regime reduces sediment deposition.

Through above-mentioned analysis, utilize the energy of river waterflow, increase the sand content of current, can accomplish, but contain sand in the water, be to deposit, the speed of deposition is directly related with the effect of desilting, if the sand content that has increased, very fast deposition gets off, just it can not be taken away, just weaken or do not reach dredging effect.

Department being engaged in silt particle and alluvial research no matter be the actual measurement of rivers, still carries out model testing, can obtain definite data, and the analysis qualitatively of the work here is for direction is found out in the regulation and the desilting in river course.

At first the speed of the deposition of silt particle and current has substantial connection.For example current enter reservoir, and flow velocity descends rapidly, so the reservoir tail end that descends rapidly at flow velocity deposits serious.At the turning, river, convex bank limit flow velocity is starkly lower than main stem for another example, thus the alluvial sand waste appears, and strengthen gradually.

Secondly with the granule size of silt particle, relevant with the physical characteristics such as size of silt particle proportion.General downstream silt particle mostly is the suspended load of small grain size, but still is that the big slightly heavy deposition of granularity is fast, and vice versa.

The 3rd is relevant with the state of current, and turbulence level is bigger, and silt particle more is not easy to deposit.

According to the relation that contains sand, deposition and flow velocity in the current, illustrate that channel cleanout improves the important function of velocity flow pattern.

(1) deepen main stem, not only draining smoothness in river reduces flood level, reduces flood harm, and can reduce the alluvial in the low flow velocity district of shallow water, reduces the alluvial of main stem.

The shallow river width of the Yellow River downstream water, it is more and more serious to deposit, and the river course is more and more wide, and large stretch of good farmland has become the sand waste of river alluvial.As form main stem, and can improve alluvial, reduce disaster and vacate large stretch of good farmland.

(2) remove curved shoal, river, reduce river bend, can shorten the river course and increase gradient, reduce resistance, help increasing the favourable minimizing alluvial of flow velocity.

(3) hydraulic desilting process increases for preventing silt content, the new alluvial district that causes harmfulness for the downstream, generally should still first downstream after the upstream, tributary behind the first master stream, Heavenly Stems and Earthly Branches flow point section is carried out.

For making current increase turbulence level, the conscious river bed that makes formed waveform during desilting was long-pending.(as accompanying drawing five)

Contain sand, speed and alluvial in the research rivers water

Characteristic just more can easily understand that, the critical role of river channel sedimentation cleaning in river management.

Grasp the relation of silt particle deposition velocity and flow rate of water flow and silt particle characteristic, just can determine the channel cleanout scheme.

Utilize natural conditions, solve the harm that natural phenomena is brought to us, the great rivers siltation volume is big, and the desilting workload is big, but his energy potentiality is also big, and that utilize is reasonable, is bound to obtain satisfied effect.

Design considerations

Its principle is to utilize natural conditions, reaches dredging waterway and desilting purpose.His design must adapt to, and uses the natural conditions of this equipment, has had natural conditions to consider to use again bigger scope is arranged as far as possible, is exactly the foundation of design.

The natural conditions parameter of foundation is as follows:

1. use the flow in river and the conditional curve of time;

2. use the flow velocity in river and the conditional curve of time;

3. use the flow in river and the conditional curve of water level;

4. use the river the river sand content (long-time average annual value, maximum measured value, flood season long-time average annual value) and the physical characteristic of silt particle.And the situation of change of each section silt content along the river.

5. use the river to use the section section configuration.

Design performance and structural requirement

1. utilize the principle of collapsible tube, flow rate of water flow in the rivers is improved 10～15 times, requiring has the impact force of having dashed silt particle, keeps bigger impact area, best with the ability in the entry of silt particle mud in order to obtaining.

2. to the requirement of water outlet nozzle

(1) energy is upper and lower, move left and right (as principle schematic) can better be approaching, (should be leaned on the river bed) towards the silt particle position to reduce the current submerge loss.

(2) nozzle should be provided with the control that changes flow and cuts down, and can adjust exit velocity, increases the scope that adapts to inlet velocity, adjusts flow velocity and obtains optimum efficiency.

(3) nozzle has high speed to contain sand water stream process, uses the anti-abrasive material manufacturing, improves application life.

3. rectangle is generally selected in the import of collapsible tube section for use, and width (b) is (h) highly.(as accompanying drawing six);

(1) size of b * h section, decision utilizes the size of flow energy, should determine with the ability that requires desilting according to the flow size of river.

(2) scale of b, h should be determined according to the degree of depth of current and width, and general import should be considered that the top is green and floods 1-2 rice work under water for well.

(3) in order to reduce the collapsible tube loss, total contraction angle is not more than 16 °, and inlet edge should be with garden arc transition (as principle schematic).

4. the device design should be considered, device body sinks near the river bed during work, moves when changing jobs the position, can move by lifting device.Device can be designed in the middle of two boats and ships, to install additional can lifting Accrete clearing device (as accompanying drawing two); Also can be designed to install additional in existing hull bottom (centre or both sides) can lifting Accrete clearing device; (as accompanying drawing three) also can be designed to Accrete clearing device and boats and ships one, energy sedimentation, the dredger that floats.

5. fix during for work, the grasp or the anchor post of some should be arranged.

6. the hull operation should be housed, facilities such as sand washing usefulness measuring instrument and safety, illumination.

7. description of drawings: accompanying drawing one riverbed current automatic desilting principle of device schematic diagram

1. desilting switch board; 2 nozzles; 3. active segment; 4. a commentaries on classics structure of an essay; 5. become the section pipe; 6. collapsible tube.Accompanying drawing two: structural concept one 1. oceangoing ship ships; 2. desilting switch board; 3. Accrete clearing device 4. Accrete clearing device cranes; 5. lifting switch board.Accompanying drawing three: structural concept 2 1. desilting switch boards; 2. oceangoing ship ship; 3. Accrete clearing device; 4. Accrete clearing device crane; 5. lifting switch board.

From current China river management situation, it is poor that quite a lot of downstreams of doing are administered in the upstream, and weak link is in the downstream; The improvement in downstream biases toward again and intercepts, and despises desilting, if make the downstream be in benign cycle, emphasis must be placed in the desilting; The downstream mostly is industry, agriculture developed regions, and emerging city, the star Luo Qibu of township enterprise are densely populated, and as disaster, the loss to national economy causes does harm to maximum also in the downstream to the people's lives and properties prestige; Therefore the emphasis of river management also must be in the downstream of rivers from now on.

But the improvement of downstream river is intercepted with the desilting workload is huge and is worked under hard conditions, and difficulty is big, huge is expensive, is our economic capability, is difficult to bear, and we build water conservancy projects, quicken the improvement of rivers, improve the realization of the ability task and goal of resisting nature disaster, bring bigger difficulty.

The current of rivers are being contained it huge energy without cease of inexhaustible usefulness, use it for the improvement river course, can save great amount of manpower and material resources and energy consumption, as long as solve the certain device investment, just can carry out the improvement in river course as river waterflow all the year round.Water-control, the condition with by nature changes the harm that natural conditions are brought to us, be the good measure direction of good method enemy, the effect that is bound to obtain is bound to quicken the process that rivers are controlled, make rivers move towards the track of benign cycle operation early, rivers are more benefited for the people.

I do not do river management, am the layman to alluvial and desilting, and to the means of alluvial characteristic and removing, going back of understanding is few.Particularly to the sedimentary condition of silt particle and the accurate data of deposition velocity, going back of grasp is few, so at actual conditions, really but calculate dredging effect, the concrete scheme of desilting is also had any problem.I want to need only needs through model testing, or the small-sized site trial of rivers, the full and true but result in the garden of can obtaining.

The hydraulic desilting ship can become the good equipment of river regulation, can achieve success, and makes a due contribution.

Annotate: once used " submersible type riverbed auto hydraulic dredger " title, content is identical.

Claims (2)

1. Present technique is to utilize the river silt content to depend primarily on the natural law in silt particle source, utilizes the river energy of flow, increases the silt particle source, increases the river sand content, and the alluvial silt particle is taken away the purpose that realizes desilting.

   Be different from existingly fully, the various dredge boats of very strong driving force equipment are housed.

   This device does not have power consumption; Can move throughout the year; Maintenance and the attached expense that helps are low; Apparatus cost is several times lower than than general dredge boat, and even tens times.

   Claim:

   1, utilizes river silt content size, depend primarily on the natural law in silt particle source, the energy that utilizes river to flow, adopt collapsible tube and control corresponding mechanism, increase river silt particle source, increase the river silt content, with current silt particle is taken away, reality is removed the principle of alluvial silt particle.
2. 2, with collapsible tube and outlet turning controlling organization, the Accrete clearing device of forming, and install liftable Accrete clearing device additional and install Accrete clearing device that can lifting additional and Accrete clearing device is heavy with ship one physical efficiency, the structural shape of three kinds of desilting equipments of dredger of floating in various hulls bottom (centre or both sides) in two oceangoing ship amidships.

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