How to choose the most popular concrete trailer pu

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How to choose and buy Concrete Drag Pumps

the hydraulic concrete pumps in China include the following aspects: high temperature test, thermal shock test, cold and hot cycle test, steel needle puncture test, heavy object impact test, extrusion test, overcharge performance test, forced discharge performance test, external short circuit test, reverse charging test and other effective and safe test meetings. The trial development started in the late 1970s, Domestic enterprises producing full hydraulic double cylinder concrete delivery pumps have grown from scratch, and more than 100 large and small concrete drag pump manufacturers have sprung up, with the output of more than 1000 Drag Pumps being introduced to the market every year. Although the market development situation is good, due to the imperfect production supervision system of the government's concrete pump, and some manufacturers' imitation assembly and rough manufacturing, the whole machine is equipped with Italian original imported oil pump units and independent low-noise hydraulic clamping oil sources, forming a mixed situation in the concrete drag pump market. Based on many years of experience, the author of this paper puts forward some suggestions on how to distinguish the advantages and disadvantages of concrete Drag Pumps, and from what aspects can we choose concrete Drag Pumps with high quality, low price and excellent performance, for everyone to discuss

characteristics of concrete pump

(1) towed concrete pump has the following characteristics in Construction: ① high degree of mechanization, less labor required, simple construction organization; ② The transportation and pouring of concrete are continuous, with high construction efficiency and fast project progress; ③ The pumping process has strict requirements on the quality of concrete. It can also be said that pumping is an inspection of the quality of concrete. Because the pumping is continuous, the concrete is not easy to separate during the pumping process, and the loss of concrete slump is small, so it is easy to ensure the quality of the project; ④ Safe operation can reduce the danger in the construction process; ⑤ It has strong adaptability to the construction operation surface and wide operation range. The concrete transmission pipeline can be laid to other places that are difficult to reach, and the concrete can be filled and poured in place under a certain pressure. It can also be used in series with pumps to increase the transmission distance and height to meet various construction requirements; ⑥ The mutual interference with other construction machinery is small, and other construction operations can be carried out near the delivery pipe while pumping; ⑦ Under normal pumping conditions, the concrete transported in the pipeline will not pollute the environment and meets the environmental protection requirements

(2) there are also some limitations in the use of towed concrete pump construction, which are mainly reflected in the following aspects: ④ the mix proportion of concrete should not only meet the requirements of project quality, but also meet the requirements of pipeline transportation, such as certain requirements for slump, maximum particle size of concrete aggregate, proportion of water sludge and fine aggregate, etc. ② the transportation operators of concrete pump should have a certain technical level, We should not only master the use and maintenance methods of machinery, but also know some knowledge of concrete construction technology, and be able to judge the quality and pumpability of concrete: ③ the conveying distance of concrete is also limited by the diameter of conveying pipe, the performance of distribution valve of towed concrete pump and outlet pressure; ④ Towed concrete pump is difficult to transport dry and hard concrete, which limits the scope of use of towed concrete pump; ⑤ When the temperature is lower than - 5 ℃, special measures need to be taken before pumping

classification of concrete pumps

(1) classification method of concrete pumps. According to the driving methods of concrete pumps, there are piston type and extrusion type, as well as hydraulic diaphragm type and air tank type pumps. At present, most of them are piston type

according to the transmission mode of concrete pumps, piston concrete pumps are divided into mechanical piston pumps and hydraulic piston pumps. At present, most of them are hydraulic piston pumps. The hydraulic piston pump can be divided into hydraulic type and oil pressure type according to the different media driving the piston, and most of them are oil pressure type

classified according to whether the pump can move: there are fixed concrete pumps, towed concrete pumps and vehicle mounted concrete pumps, of which towed pumps and vehicle mounted pumps are widely used

according to the form of directional valve, there are rotary valve, gate valve and S-shaped pipe valve, etc. at present, gate valve and S-shaped pipe valve are widely used

(2) advantages and disadvantages of gate valve and S-shaped pipe valve. The main advantages of the gate valve concrete pump are simple structure, convenient maintenance, large reversing force and good suction performance. The requirements for concrete are not as high as those of the S-shaped pipe valve concrete pump, and it can pump self mixing concrete (suitable for the pumping of low slump concrete): however, the sealing of the gate valve is limited by the structure, and the sealing pressure is low. During construction, it is inevitable to use Y-shaped pipe to connect the double cylinder body and delivery pipe of the concrete pump, The Y-shaped pipe will produce a large pressure loss. That is, the percentage of the reduction of the minimum cross-sectional area of the test bar to the original cross-sectional area after breaking. In addition, when using the gate valve for transportation, it is also required to install a horizontal conveying pipe section in front of the vertical conveying pipe, whose length is 1/2 of the concrete lifting height. Because the ram is very sensitive to the backflow caused by the fluid pressure generated by the vertical direction of the concrete, forming a hydraulic resistance, which will reduce the conveying height of the concrete, which is also one of the main factors limiting the conveying height of the ram valve concrete pump

the main advantage of S-shaped pipe valve is that the swinging pipe orifice is flat and easy to adjust after wear. Its sealing performance is very good, so the delivery height of S-shaped pipe valve pump is higher than that of ram valve pump of the same specification. The parabolic principle is adopted for design, which makes the material flow more reasonable and further reduces the resistance. At present, as shaped pipe valve is the most widely used concrete distribution valve. Its main characteristics are simple structure, smooth flow channel and small flow resistance of concrete; Good sealing performance and high pumping pressure: the height of the hopper from the ground is low, which is convenient for the concrete mixer truck to unload to the hopper; Fast reversing speed, low noise, etc

main technical parameters of towed concrete pump

(1) theoretical delivery capacity. Theoretical value of concrete volume delivered by concrete pump per hour (m3/h)

theoretical conveying capacity qt=vt × N

VT - theoretical volume of each working stroke of concrete pump (m3/time)

n - rated working stroke times per hour of concrete pump (times/h)

(2) actual conveying capacity. The actual volume of concrete delivered by the concrete pump per hour (m3/h)

actual conveying capacity qa=qt × Kv

volumetric efficiency kv=0.8-0.9

(3) pumping concrete pressure. Concrete pressure at the outlet of concrete pump during operation (MPA)

basic structure of towed concrete pump

towed concrete pump is mainly composed of main power system, pumping system, hydraulic and electric control system

(1) active power system. There are two kinds of motive power of towed concrete pump: diesel engine and motor. The advantage of diesel engine pump is strong adaptability. In some construction sites, the power supply can not meet the requirements of machines for high power, because the power of large displacement concrete pumps is generally more than 100kW, and the diesel engine can not consider the power supply. This is the reason why diesel pump has been favored by users. The advantage of motor pump is low price and low noise, which is undoubtedly more suitable for urban construction with increasing environmental protection requirements

(2) pumping system. This system is the actuator of the concrete pump, which is used to continuously transport the concrete mixture to the pouring site along the transmission pipeline. Generally, the pumping conditions of concrete pumps include high-pressure small displacement and low-pressure large displacement. Users can choose reasonably according to the requirements of the project on the concrete conveying height (or distance) and displacement

the switching methods of high pressure and low pressure include replacing the rubber hose, rotating the position of the valve block and manual reversing valve. Most of the newly developed products have adopted the fully automatic high and low pressure switching technology. Turning the electric control button, the high and low pressure switching can be completed in an instant, fast and convenient. In addition, the new products also adopt the automatic piston withdrawal technology. As long as the button is pressed, the concrete piston can be returned to the water tank. Using this technology can greatly shorten the time of assembling and disassembling the concrete piston and reduce the labor intensity of the operator; At the same time, the concrete piston can be withdrawn at any necessary time to check the wear of the concrete seal, or it can be cleaned and maintained, so as to prolong the service life of the piston

(3) hydraulic and electric control systems. The hydraulic system has open system and closed system. The open system has the advantages of low hydraulic oil temperature and high cleanliness; The closed system has the advantages of small hydraulic oil tank and compact structure. Most domestic products use these two systems. The electric control system is generally controlled by PLC, and some products are also equipped with text displays and touch buttons, which have a good man-machine interface. The monitors distributed in each part of the concrete pump send signals to the PLC controller, which displays the working state of the concrete pump through the text display. In case of abnormality, the protection program set in the system will be started immediately to protect the concrete pump from damage. At the same time, the cause of the fault will be displayed on the text display, which can facilitate fault diagnosis and maintenance

comprehensive analysis of brands and services

it is not difficult to choose from the "hardware" configuration of the pump, but also from the "software" analysis. There is little difference in the main configurations of concrete pumps on the market. The biggest difference is the reliability of products and the after-sales service of manufacturers. Our company has passed the ISO9001:2000 quality system certification and has strong technical strength. It is the largest construction machinery maintenance center in Shandong and has no worries about after-sales. (end)

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