The blowing filling scheme of the vertical sand pump set designed by OCEAN Pump is to simulate the principle of natural water erosion, and use the action of hydraulic power to carry out sand and mud excavation work. The water is pressurized by the high-pressure pump, and the high-pressure and high-speed water column is ejected through the jet of the water gun. The water column impacts the soil and sand, making the soil and sand wet, disintegrated, and mixed into a mixture of mud and mud, which is then lifted by the vertical sand pump and transported to the sand field through the pipeline. The water conservancy excavation and filling unit is simple and easy to use. It can complete the processes of excavation, loading, transportation, and filling at the same time. It has the advantages of high efficiency, low cost, good engineering quality, and construction is not affected by the weather, etc. This kind of equipment is suitable for short-distance sand taking and backfilling projects. The most commonly used is to fill geotechnical bags when building embankments.

OCEAN Pump has 30 years of experience in the design of land reclamation equipment. Simply put, dredger blowing filling is to stir the sand through the dredging system. The sand pump and driving system are installed on the ship to suck the sand through the pipeline and then discharge it to the designated place. This is also the most commonly used equipment in large-scale land reclamation projects in the world. Dredgers are generally divided into cutter suction type, drag suction type and bucket wheel type, etc. There are large, medium and small dredgers. Due to the limitations of natural conditions such as sea waves and water depth, most of the dredgers used for land reclamation are medium and large.

Generally, medium and large dredgers are equipped with two sand pumps, one for sand suction and one for sand discharge. The sand suction pump is mainly the sand pump with the larger flow rate in the same diameter, because the larger the flow rate of the same pipe diameter, the faster the flow rate, and the greater the driving force to the sediment, that is, the commonly referred to as the greater suction. The sand discharge pump is mainly considered to have a higher lift under the same pipe diameter, which can meet the requirements of long-distance transportation. Of course these are relative. Some medium and large dredgers are also equipped with underwater sand pumps. Small dredgers are generally equipped with only one sand pump for self-priming and self-unloading. When selecting dredgers, the OCEAN Pump engineers mainly makes personalized overall solutions for dredging pumps based on the specific needs of customers and the configuration needs of the entire set of equipment, including drive systems, hydraulic systems, control systems, etc.

In a land reclamation project in Shanghai, China, in 1997, vertical sand pumps were used for construction at the beginning. Since the sand intake site was more than 4,000 meters away from the sand discharge point, the head of vertical sand pump was too low to transport it. The project leader consulted OCEAN Pump to solve this problem for him. After on-the-spot investigation, the OCEAN Pump engineers designed six sets of 22kw vertical sand pumps to discharge sand to a closed tank, and the tank was connected to a large horizontal sand pump.

The total flow of 6 vertical sand pumps is 1500m3/h, and the flow rate of the large horizontal sand pump we selected is also 1500m3/h to match the vertical sand pump flow. In this way, the sand can be transported to a distance of 4000m through the horizontal pump pressurization. The customer adopted OCEAN Pump design scheme and the result was a success in one fell swoop. Later, this method was adopted in China’s largest sea reclamation projects such as Pudong Airport, Jinshan Petrochemical, Chongming Island, Changxing Island, and Hengsha Island.

(1) Sea reclamation by means of suction, transportation and blowing

This form of reclamation is to use a sand suction ship equipped with one or more large flow, low head sand pumps. The sand suction ship is driven to the legal area with rich sand sources for sand suction operation, and the sand is sucked to the sand transport ship. The sand transport ship is driven to the nearest shore of the reclamation project, and a sand blower ship is arranged at this position, and the sand is sent to the designated area through the sand blower ship. In practice, due to the different environments, different sources of sand, and different transportation methods, OCEAN Pump engineers and customers jointly designed and used several different sand blowing methods.

(2) Vertical sand pump combined with high-efficiency sand pump for sand blowing

At present, the specifications of commonly used sand transport ships are between 3000 tons and 10000 tons, the length of the whole ship is between 45m and 80m, and the length of sand bins is between 35m and 60m. This working condition is generally used in coastal areas, and has relatively high requirements for sand pumps, supporting power, and ship platforms, and needs to pass ship inspection certification. OCEAN Pump, ship design institute and shipyard jointly design and develop sand blowing ship. Each sand blowing ship is equipped with 5-10 vertical sand pumps, a marine and land dual-purpose sediment pump, 2 high-pressure water pumps and other related equipment. The sand blowing ship is equipped with a hanger and a hydraulically controlled high-pressure water gun. At the same time, 5-10 vertical sand pumps can be hoisted to extract the sand in the sand bin, and the sand is supplied to the marine and land dual-purpose sediment pump for long-distance transportation. This method greatly reduces labor and operating costs and improves work efficiency.

(3) High-efficiency sand pump combined with funnel sand blowing ship

Many large sand transport ships choose to install conveyor belts, which can transport the sand in the sand bin through the conveyor belt. OCEAN Pump engineers worked with customers to design and develop a funnel ship sand blowing system. Making a funnel-shaped sand tank in anther ship, and the conveyor belt on the sand transport ship extends directly above the funnel sand tank to discharge the sand into the funnel. A high-pressure replenishment water pump and a marine and land dual-purpose sand pump are installed on the outside of the funnel sand tank. Through the pipeline branch, the high-pressure replenishment water pump provides high-pressure water to impact the sand layer to form sand slurry, then the sand slurry is supplied to the sand suction pump at the bottom of the outer side for pumping and transportation.

The use of the marine and land dual-purpose sand pump in combination with the funnel can increase the extraction concentration, and the maximum can reach 50% according to the medium type. In addition, in this way, the marine and land dual-purpose sand pump has a small probability of cavitation, which reduces the damage probability to the marine and land dual-purpose sand pump.

(4) Marine and land dual-purpose sand pump combined with grab bucket blowing ship or excavator type sand blowing ship

In addition to conveying the sand in the sand transport ship through the conveyor belt, there is also a method of lifting the grab bucket or excavator digging to cooperate with the funnel sand tank to convey. This method is suitable for use in ports with complete infrastructure, where there are berths for installing grabs, it is easy to unload. This method is mostly used for unloading coal, ore, ore powder, etc.

The above are the various applications of sand pumps in sea reclamation. Each method has its own characteristics, and there is no distinction between advantages and disadvantages. The important thing is that it is suitable for the respective project environment, construction period, investment and other requirements.