In 1943, the citizens of Los Angeles suffered a haze attack for the first time in history. Since then, they have been fighting for more than half a century. 70 years later, the word “Smog†became the most popular word of the year in 2013 in China. Especially during the recent two sessions, according to the Baidu Index mobile data display, the relevant search volume of “Smog†showed a trend of sharp increase. In the 2014 TOP10 hot topics forecast TOP10 distribution, “Smog†ranks fourth with 43% of the search share. one. An anti-haze warfare that is closely related to everyone has already started with the two clubs' heavy punches and opened the curtain.
On March 5th, Premier Li Keqiang made a "Government Work Report" to the National People's Congress and pointed out that this year the Chinese government will "declare war on pollution as hard as it is to declare war on poverty." Li Keqiang also proposed in 2014 that the country will supply four standard cars across the country. With diesel, the release of the signal that there is no room for environmental protection standards will speed up the implementation of the four national standards. In the following topics, the management of haze and the protection of the environment have become one of the important topics discussed with the Prime Minister.
The controversy over whether car exhaust emissions are the biggest culprit in air pollution has not stopped and concluded. What is certain, however, is that commercial vehicles are much more polluting than cars. National People's Congress deputy and chairman of Yuchai Group's board of directors Yu Ping said in the two sessions: “Although the number of commercial vehicles is about three times less than that of passenger vehicles, the volume and mileage of a single commercial vehicle is much larger than that of passenger cars. More than that, its overall percentage of exhaust emissions is very high."
When it comes to tailpipe emission standards, ordinary consumers tend to be as ignorant as they do not understand the drug label. However, there is one point we need to know. Every level of emission standards for automobiles, emissions of pollutants can be reduced by 40%-50%. At present, China's passenger vehicles have already begun to implement the national five emission standards, while commercial vehicles still remain in the country's three emission standards.
Since 2010, the Ministry of Environmental Protection-based management department has been working to improve the emission standards of commercial vehicles, and has replaced the National III emission standards with the fourth national emission standard in the hope of reducing hydrocarbons, nitrogen oxides, carbon monoxide, and PM. Substances entered the atmosphere, but the implementation time was postponed from January 1, 2011 to January 1, 2012, and then to July 1, 2013. However, to this day, another boot that raises the emission standard has not been seen yet. Landing.
Relevant sources believe that the emissions from commercial vehicles must meet the National 4 standards and involve upgrading the technologies and products of diesel engines and related industries. China’s technologies and products related to these industries are lagging behind those of Europe and the United States. However, the fact is that many automobile companies in China have the strength to manufacture automobiles that meet the national or national emission standards. For example, the SAIC Group's recently introduced SAIC G10 has already had the technology to produce five-emission engines in the country. It was previously in the commercial vehicle market. The well-received V80 products also have the technical reserves to upgrade the country's five emission standards. However, the two barrels of oil are still provided with low-quality, low-quality oil. The escalation of oil production leads to “inconsistent vehicle oil,†and even a powerful engine that consumes such oil will eventually lead to impaired fuel economy. Whoever drags down the process of raising the emission standards of commercial vehicles must not be self-explanatory. You understand.
Raising emission standards is a general trend, but in China, relevant policies and regulations are not in place, and many companies will not actively implement the cost of raising costs. According to professional sources, the increase in the cost of a light commercial vehicle from State III to National IV is about 10,000 yuan. In addition to Beijing, Shanghai, Nanjing, Ningbo, Chengdu and other places, in 2013, announcements were successively issued that diesel vehicles (including light-duty vehicles) would implement the four national standards, and other cities chose to be able to delay. According to an online survey recently conducted by the reporter, the majority of the second and third lines still do not have mandatory standards for light passenger vehicles.
The intensification of haze may become an opportunity to push up the emission standards for commercial vehicles. Especially with the emphasis and promotion of the two associations, commercial vehicle emission standards will surely have a leap forward in 2014. For SAIC Datong and some other car manufacturers with keen sense of smell, they have not stopped the technical reserve of the highest domestic emission standards. As early as in 2011 when SAIC V80 officially went public, it adopted the latest Italian VM technology and the third-generation high-pressure common rail technology. With turbo technology to meet the highest domestic emission standards. Such enterprises will inevitably lead the enterprises to upgrade by the attitude of the technology leader.
As Premier Li Keqiang emphasized in the two sessions, the governance of haze cannot “wait for the wind and rain†and take the initiative. If it is in foreign countries, the state will provide some corresponding subsidies for enterprises that have relatively high implementation standards in the environmental upgrade of commercial vehicles. For consumers, buying the model with the highest emission standards in a single step is undoubtedly the best in their ability and ability.
Dredging is an excavation activity usually carried out underwater, in shallow seas or freshwater areas with the purpose of gathering up bottom sediments and disposing of them at a different location. This technique is often used to keep waterways navigable. It is also used as a way to replenish sand on some public beaches, where sand has been lost because of coastal erosion. Dredging is also used as a technique for fishing for certain species of edible clams and crabs (see fishing dredge).
Photo of our Dredger :
Types of dredging vessels
Suction
The dredge Drag Head of a suction dredge Barge on the Vistula River, Warsaw, Poland
The Geopotes 14 lifting its boom on a canal in The Netherlands. (gēopotēs is Greek for "that which drinks earth")
For suction-type excavation out of water, see Suction excavator.
These operate by sucking through a long tube, like some vacuum cleaners but on a larger scale.
A Plain Suction Dredger has no tool at the end of the Suction Pipe to disturb the material. This is often the most commonly used form of dredging.[citation needed]
Trailing suction
A trailing Suction Hopper Dredger (TSHD) trails its suction pipe when working. The pipe, which is fitted with a dredge drag head, loads the dredge spoil into one or more hoppers in the vessel. When the hoppers are full, the TSHD sails to a disposal area and either dumps the material through doors in the hull or pumps the material out of the hoppers. Some dredges also self-offload using drag buckets and conveyors.
The largest trailing suction hopper dredgers in the world are currently Jan De Nul's Cristobal Colon (launched 4 July 2008) and its sister ship Leiv Eriksson (launched 4 September 2009. Main design specs for the Cristobal Colon and the Leiv Eriksson are: 46,000 cubic metre hopper and a design dredging depth of 155 m.[3] Next largest is HAM 318 (Van Oord) with its 37,293 cubic metre hopper and a maximum dredging depth of 101 m.
Cutter-suction
A cutter-suction dredger's (CSD) Suction Tube has a cutting mechanism at the suction inlet. The cutting mechanism loosens the bed material and transports it to the Suction Mouth. The dredged material is usually sucked up by a wear-resistant centrifugal pump and discharged either through a pipe line or to a barge. Cutter-suction dredgers are most often used in geological areas consisting of hard surface materials (for example gravel deposits or surface bedrock) where a standard suction dredger would be ineffective. In recent years, dredgers with more powerful cutters have been built in order to excavate harder rock without the need for blasting.
The two largest cutter suction dredgers in the world are currently (as at August 2009) DEME's D'Artagnan (28,200 kW total installed power)and Jan De Nul's J.F.J. DeNul (27,240 kW).both built by IHC Merwede.
Auger suction
This process functions like a Cutter Suction Dredger, but the cutting tool is a rotating Archimedean screw set at right angles to the suction pipe. The first widely used auger dredges were designed in the 1980s by Mud Cat Dredges, which was run by National Car Rental, but is now a Division of Ellicott Dredges. In 1996, IMS Dredges introduced a self-propelled version of the auger dredge that allows the system to propel itself without the use of anchors or cables. During the 1980s and 1990s auger dredges were primarily used for sludge removal applications from waste water treatment plants. Today, auger dredges are used for a wider variety of applications including river maintenance and sand mining.
The most common auger dredge on the global market today is the Versi-Dredge. The turbidity shroud on auger dredge systems creates a strong suction vacuum, causing much less turbidity than conical (basket) type cutterheads and so they are preferred for environmental applications. The vacuum created by the shroud and the ability to convey material to the pump faster makes auger dredge systems more productive than similar sized conical (basket) type cutterhead dredges.
Dredger
Cutter Suction Dredger,Bucket Dredger,Grab Dredger,Trailing Hopper Suction Dredger
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