Unloading dredge pump is the dredge pump specially designed to unload sand or slurry from the boat. The sediment mixture should transported to the designated location such as construction sites after river dredging and sand extraction from sand barge using the sand pumps or excavators to discharge the sand to the landfill area. How to unload the sand or slurry from sand or slurry barge by using unloading dredge pump? which kind of dredge pump is the cost effective options? How to choose suitable sludge and sand unloading pumps to achieve the long-distance transportation ? What is the approximate cost of silt unloading? Based on the accumulation of construction plan design, we wanted to give you following advices.
1. Singe Head Sand Blowing
Single-head blowing is the most widely used method of unloading sediment in Jiangsu, Zhejiang and Shanghai Province. An unloading dredge barge is built with the 350PNS-35 marine dredge pump unit and the CH350 high-pressure water pump unit which is placed in the pump bin, and matched with Weichai 6170 series 450 horsepower and 320 horsepower marine diesel engines. The suction pipe and high-pressure water pipe are controlled by hydraulic arms and placed in the sand silo. Through the impact of high-pressure water, the sand mixture is sucked into the sand suction pipe, and then the dredge pump is used to achieve 1000 -1500 meters long-distance transportation.
Usually, Unloading 300 cubic meters slurry can be completed within 40 minutes. When unloading slurry or sand for each ship of 300 cubic meters, the consumption of diesel oil is about 40 liters. The pipeline uses an inner diameter of 350mm, the approved specific gravity is about 1.15, and the flow rate of the solid-liquid mixture is 3.46 m/s is based on transporting 1500 meters.
The single-head sand blower is suitable for loading and unloading of small and medium-sized silt-carrying barges, which greatly reduces the use of manual labor. One barge needs two people to operate. This kind of construction plan is relatively mature, and a set of equipment can realize the unloading, The scheme of long-distance transportation of sediment, and the sediment can be transported to sites with dozens of kilometers away through series connection.
2. Unloading dredge Sand by Vertical Slurry Pump
Vertical sand pumps are the most widely unloading dredge pump used on sand blowing ships. The vertical sand unloading pump unit is hoisted on an electric hoist. After the sand transport barge approaches, the vertical sand unloading pump is dropped on the sand surface for operation mainly using high pressure. The water impact flushes the sand-water mixture to the pump port of the vertical sand unloading pump, and then uses strong suction to transport the mortar. Usually, the number of pump sets is flexibly selected according to different job requirements, and the driving method is often a motor.
The biggest advantage of this method of unloading sediment is high concentration and high efficiency. The disadvantage is that there are more sand unloading pumps. The vertical sand unloading pump is a medium-speed machine, which wears faster and has a lower head. If long-distance transportation is required, a relay pump can be added to the ship. The vertical sand unloading pump is connected in parallel and then connected in series to the relay pump inlet, and then transported out. If it is at the pier, some customers will also repair a sedimentation tank, and then use a horizontal pump to suck and blow the sediment in the sedimentation tank to a distance of one kilometer away.
According to different construction requirements, users usually choose the 6PNSL and 8PNSL unloading dredge pump. The discharge capacity of each pump is about 50-100 m3/h. From 2015 to 2018, in the reclamation project projects in Zhoushan City, Zhejiang Province, each sand blower is equipped with 10 8PNSL vertical sand unloading pumps. The 3,000 cubic meters boat will blow in about 3 hours. A 400GN-50 marine relay pump on board can transport sand at a distance of 1,000 m3 per hour. In order to meet the construction requirements, the ship also has a 600kw generator set and two high-pressure water pumps produced by the ocean pump industry. The pipe uses a 400mm inner diameter and a specific gravity of about 1.2, the calculated pressure drop is 5.45 bar and the flow rate is 4.41 m/s.
3. Excavator Bucket or Grab Match with Marine Unloading Dredge Pump
Some small sand transport ships with flat bottom have very strong viscosity and sometimes with some gravel or particle and cannot be flushed with ordinary water guns. Many customers choose to use excavators or grab buckets to dig out the sand and then design a funnel to pour the sand into the funnel. Cooperated with high-pressure water impact and a vacuum screen, and then a mesh plate or grid is specially designed to block stones or large particles from the outside, and then a horizontal mud unloading pump is added at the bottom of the funnel to realize the extraction and transportation of the sediment on the ship. According to different transportation conditions, you can choose different head ship mud pumps.
A cases in Zhongshan, Guangdong Province. with this method, using two excavators to work alternately, a 400GN-50 Dredge Pump Driven by the 8170 series diesel engine is chosen with 1 set 14-inch high-pressure water pump. The dry mud extraction volume can be up to 600 cubic meters per hour. If connected with 1000 meters 400mm inner diameter HDPE pipe, the fuel consumption of two units is about 110 liters per hour. The specific gravity is about 1.2, the calculated pressure drop is 3.63 bar and the flow velocity is 4.41 m/s.
4. Unloading the sand by bottom open unloading dredge pump or pulley belt dredge pump
Both open-bottom ships and belt ships usually have a self-unloading function, so you don’t have to worry about the size of the ship, just choose different construction schemes according to the output.
4.1 Open-bottom ship
The open-bottom ship is to pull up the bottom of the ship through iron chains. After transporting it to the river, loosen the hinges and open the bottom of the ship, so that the sand in the cabin leaks into the river, so that the ship can drive away. To load the sand, use a jet-type sand pump to absorb the sediment. The advantage of this operation method is that the unloading is not limited by time and does not require close cooperation. A jet-type sand pump can simultaneously extract multiple The silt of the bottom boat
A user from Hepu, Guangxi province uses three 1003 open-bottom boats and two 10-inch jet boats for cyclic operation. The open-bottom boats are self-priming and self-unloading. The amount of sand pumped per hour is about 80 cubic meters. After being discharged to the bottom of the river, A 10-inch jet boat can extract 100 square meters of sand from the bottom of the water in about an hour. Compared with other methods, it is cheaper and more flexible.
4.2 Belt unloading sand ship
The belt unloading sand ship is even simpler. The customer’s sand ship has a self-unloading function. If the sand on the belt ship needs to be transported over a long distance, it needs to use a funnel. The marine sand unloading pump is placed at the bottom of the funnel and is diluted and transported out with the help of a high-pressure water gun. If the belt ship can be docked, build a funnel at the dock, and then use the marine sand unloading pump to transport the sand in the same way.
The reclamation project of Hong Kong Kai Tak Airport uses a belt ship and a funnel. After the large belt ship docks, a hydraulic gate is added to the bottom of the funnel to control the amount of sand, and then the high-pressure water mixed with the sand enters the ZS350 large-scale sand unloading pump Among them, the ZS350 sand unloading pump is matched with a Weichai 8170 1000 horsepower 1500 rpm diesel engine. The sand conveying distance is 1000 meters. The pipeline uses ultra-high molecular polyethylene pipes, and the sand unloading capacity is about 400 cubic meters per hour. The pipeline has an inner diameter of 350mm, the calculated pressure drop is 3.58 bar, and the flow rate is 4.03 m/s.
5. Unloading the sand by the sand barge with pump bin
The bottom silo of some sand transport ships has a special marine sand unloading pump silo, which is also controlled by a hydraulic top. When the sand ship docks, connect the sand discharge pipeline, and then slowly open the bottom. The high-pressure water pump is also used to fill clean water, and then use The ship uses a sand unloading pump to transport sand to the shore.
A large self-unloading sand carrier made by a user in Shantou, Guangdong uses a 500GN-60 large marine sand unloading pump to unload sand in this way. The pure sand is transported 1,000 cubic meters per hour and the transport distance is 2500 meters. It is equipped with a Cummins 2400 horsepower diesel engine and For 1260 type marine gearbox, the pipeline is 500mm. The calculated pressure drop is 6.21 bar and the flow rate is 4.23 m/s.
Conclusion
The unloading of silt has been a problem that has been encountered since the beginning of shipping. From the previous manual transportation, the use of unloading pumps and unloading pumps has achieved a great leap, but if it can be used flexibly in construction. The combination of different pump types often brings twice the result with half the effort. To The engineering team of the ocean pumping industry will formulate different sand unloading construction plans according to different types of sand transport ships in different regions. Small ships are relatively flexible and there are more choices. The construction of large sand transport ships is usually a problem. As you move your whole body, you must be cautious when choosing and choose a professional team to make a plan and make a construction plan.
Tai’an Ocean Pump Co.,ltd. is a manufacturer and supplier of sand pumps, large-scale sand suction pumps, slurry pumps, mud pumps, sediment pumps, sewage pumps, dredging pumps, sand pumps, sand dredgers, submersible slurry pump and other equipment. OCEAN Pump integrates independent research and development, equipment manufacturing, pre-sales and after-sales service. Our business covers sand suction and dredging projects. The products cover 20 series and more than 500 specifications. The products are exported to 36 countries and regions. Ocean Pump Industry has won the praise and trust of users with its rich industry experience, professional technology and excellent service.
