1, concrete pump selection 1.1 classification From the mobility can be divided into automotive concrete pump (pump), frame pump (without active boom), trailing concrete pump. From the power form can be divided into electric and internal combustion engine. From the pump form, currently widely used ramp valve and the "S" pipe valve type; the former has the advantage of the concrete aggregate diameter requirements of the wider (40 mm), the price is lower, the disadvantage is The gate valve needs to be lubricated continuously with a pumping height of about 100 m. The latter has no lubrication system and requires strict aggregate (not more than 33 mm). The pumping height can be up to 150 m and the selling price is generally higher. 1.2 Selection According to working experience, concrete equipment for large-scale thermal power plant construction is generally equipped with 2 mixing towers (stations), 3 concrete pumps, one pump towed pump or two pump towed pumps, and multiple selection of inclined gate valve In order to meet the aggregate requirements, this mobility, economy, practicality are more reasonable. 1.3 Selection Precautions (1) primary election concrete pump, be sure to visit the user, learn more about the actual use. (2) must choose the regular manufacturer mass production of concrete pump. (3) try not to use any manufacturer's first (first batch) concrete pump. (4) Should be signed with the manufacturer sales direct contract to buy, as far as possible through the middle part, in order to facilitate maintenance services. 2, new pump debugging 2.1 in the factory before the pump debugging content (1) Personnel: Technician, operator and driver each one, operator is skilled worker. (2) read the instructions carefully. (3) Check whether the concrete pump is consistent with the model number in the contract and whether the certificate number and nameplate number are the same. (4) the appearance is satisfactory, whether there is leakage, leakage at. (5) According to instructions, determine the maximum and minimum displacement of the movement of the piston movement. Such as Hubei Construction Machinery Factory HBT60 pump displacement of 8 ± 1 times / min, the maximum displacement of 28 ± 1 times / min. (6) Check the mixing system, cooling system, lubrication system is normal, the automotive jib pump must also check the boom system, leg system, the car part is normal. (7) empty load operation 2 h, review the system for any leaks, seepage, during which the pressure gauge should be normal. (8) Check all the random spare parts are complete, intact. All qualified before receiving. 2.2 on the site for the first time before using the debugging content (1) repeated manufacturers to pump debugging content. (2) Concrete pump installation site should be flat and solid, especially the leg support. Concrete pump as close to the construction site, and consider the exit route after the end of the operation. (3) layout and reinforcement of the transmission pipeline (external pipe). (4) empty load operation 10 ~ 20 min, so that the lubrication points are obviously grease. (5) in the displacement of pumping mortar 1 ~ 2 m3, when the mortar fast pump can be poured into the concrete, directly into the normal pumping. Test the pump, carefully observe the various parts of the work without exception. Such as oil pump, oil temperature, the main pressure gauge changes, the frame pump should also pay attention to boom movements and engine work, if any unusual circumstances, should be immediately shut down, find out the reasons for re-examination after troubleshooting. Do not wash the pump after pumping, carefully check the ministries have no leakage, leakage phenomenon, after passing the pump or directly into use. 3, pumping skills The difficulty of concrete pumping (ie pumping effect) generally depends on the quality of concrete itself, the pouring point distance, the size of the pipe, the situation and the prevention of pipe plugging tube, pipe plug suddenly ruled out in time. (Concrete quality of concrete pumping effect on the greater impact, but not introduced here) 3.1 duct selection According to Table 1, the maximum particle size of concrete coarse aggregate table select the appropriate duct. 3.2 external pipe layout Should be to minimize the use of elbows, pipe serious wear and tear should be located far away from the concrete pump location, so as not to over-pressure squib. Various forms of pipe converted into horizontal length (approximate). 3.3 concrete pump tube exclusion (1) anti-pump exclusion Once plugged, you can press the "anti-pump" switch, the general anti-pump run 4 to 5 trips can be ruled out. (2) When the anti-pump operation can not be ruled out pipe plugging, as soon as possible to open the plug at the duct, and remove the blockage. Note that in addition to cutting off the power before demolition, but also to completely eliminate the remaining pressure in the tube. 3.4 season construction Summer hot climate construction, should be covered with wet shrouded cloth, straw bag duct, so as to avoid the tube of concrete "dehydration", delivery difficulties. Winter cold season construction, should be wrapped with insulating material pipe, to prevent the concrete inside the pipe by the cold. 3.5 Pumping work completed precautions (1) Thoroughly clean the concrete pump and external pipe. (2) check the random tools. (3) 20min running air to make the lubrication points covered with grease. (4) safe exit from the job site. 4, routine maintenance Due to the variety of concrete pumps, here only introduce some common maintenance. 4.1 Pre-departure inspection items (1) Booms, slide valves and outriggers should be fully retracted and locked. (2) work lights, signal device is working properly. (3) Adequate fuel, grease and wash water. (4) sufficient hydraulic oil, all parts do not leak oil. (5) All kinds of plumbing, tools, appliances and accessories should be complete. 4.2 The main components inspection cycle (1) daily inspection of the appearance of damage to the deformation, loose parts exposed, operation and performance changes, leakage of oil, hose damage, lack of lubricating grease lubrication points, car driving safety factors. (2) monthly (or pump concrete 2 000 m3) Check the spool valve damage, duct wear, hydraulic oil reduction, lubrication points forced lubrication, the car routine maintenance. (3) Six months (or 12,000 m3 of concrete pump) Check the lower shell of the slide valve, damage to the conveying cylinder, deterioration of electrical components and hydraulic oil, damage to the boom, and routine overhaul of the vehicle. (4) Check the stirring device, stirring oil motor, rotary oil motor, water pump and oil pump every year (or 24,000 m3 of concrete pump) to change hydraulic oil. (5) Every two years (or 48,000 m3 of concrete pump) Check all items CAUTION Disassemble all seals for replacement, and the automobile part should be overhauled at the designated or professional repair point. 4.3 hydraulic oil and lubricating oil, fat selection Hydraulic Oil Model: Winter 32 anti-wear hydraulic oil, non-winter 46 anti-wear hydraulic oil. Sliding valve lubrication: Non-extreme pressure type 000 lithium-based grease winter, non-winter non-extreme pressure type 00 lithium-based grease. Car and the rest of the lubrication: Calcium grease No. 2 or with reference to instructions. 5, wearing parts repair 5.1 repair range In the chuck slide valve concrete pump, concrete contact with many parts, wear are very powerful, and we can repair only individual parts, the rest, such as rubber parts, concrete conveying cylinder, valve stem and other pieces of fine processing, Generally take replacement. Repairable wear parts are divided into two categories: one is the surfacing repair parts, such as the spool valve plate, spool valve cover (also known as the lower slide valve housing), the valve slide valve seat, the mixing valve; One is welding repair, mainly for concrete pipes. 5.2 Detection of wear and tear Sliding valve disc generally lower part of the serious wear and tear, when the size of new parts and wear size difference greater than 5 mm, which need to be repaired; When the need for repair; mixing blades on both sides of the corner of the serious wear and tear, when the size of the new pieces of wear and tear when the size difference of more than 8 mm, that is, to be repaired; under the bottom of the spool valve cover and both serious wear and tear when the new size and wear After the size difference is greater than 5 mm, which need to be repaired. 5.3 repair process (1) to determine the material slide valve cover chemical composition test results, C: 3.13%, Si: 2.06%, Mn: 0.83%, P: 0.102%, S: 0.126%; hardness of HB203 ~ 228; MT-4 wear-resistant cast iron. (2) electrode selection of the bottom of the surfacing should be good anti-hot cracking performance of austenitic nickel-based electrode Austrian 102, Austrian 302. In order to further improve the wear resistance of the welding site, under the premise of ensuring that the base metal is not cracked, a hard alloy electrode stack 667 is also used, and a heap 507 is used for surfacing on the surface of the surfacing layer. (3) Pre-surfacing method Before use, Austrian 102 and Austrian 302 electrodes are dried at 105 ℃ ~ 200 ℃ for 1 h with a stack of 667. The heap of 507 electrodes is dried at 300 ℃ ~ 450 ℃ for 2 h to reduce the hydrogen Content, prevent stomata. Both electrodes are used AC welding machine, the former current 100 ~ 110 A, the latter current 130 ~ 140 A. Will be surfacing parts of the surface of grease, concrete and other impurities removed, with a soft shaft grinding wheel to wear out the lack of fatigue layer, so that the surface exposed metallic luster. Use asbestos or cotton wrap the cylinder tube and the surrounding components to prevent burns when surfacing. Preheat the bottom cover to 150 ℃ ~ 250 ℃ to prevent cracks. When welding electrode movement direction using straight line method. Welding sequence using the sub-back-welding method, from the inside out, but the direction of movement of the electrode from the outside. The welding length of each section is not more than 50 mm, try to avoid the influence of welding heat. Each welding a sub-paragraph, with sharp steel tapping carefully to eliminate residual stress and prevent cracks. After welding, immediately wrapped with asbestos, so slow cooling. After cooling, with a grinder grinding surfacing part of the surface. After grinding, check by coloring method and confirm that there is no crack of 30 mm or more. Note that heap 667 or heap 507 can only be surfacing the surface layer. In addition to the delivery pipe, other wear parts can be repaired by the bottom of the valve spool, the steps can be simplified. (4) Duct repair points in four cases are as follows: ①the first tube to wring deflated flat jig can also be used instead of vices, and then prepare a diameter and duct diameter close to (slightly less than) of the steel pipe end into a projectile handle, so just to give deflated Office heating, steel pipe can be used to correct the circle. ② local wear generally only repair the elbow, because under normal circumstances, when a straight pipe wear a certain part of the rest of the part is also close to the wear limit, no repair value, while the elbow generally wear the first bend. The repair method is to cut a piece of medium size scrap on the waste pipe and grind the damaged parts and pieces with a grinder to select the welding rod suitable for the pipe. During the repair should pay attention to the curvature. The pipe hoop can be cut off in the waste pipe with a pipe hoop part of the length of the pipe carried by the ferrule should be 45 ~ 55 mm, polished with a grinder welded parts, select the appropriate welding electrode can be. ④ with wear limit hole straight (bend) tube If the hole in the slurry, the general is no longer used to repair, if you want to repair the use of small pressure available external pipe tail. In fact, the general repair of the pipe are best used in the external pipe tail, prohibit the use of the boom. 6, how to extend the life of the slide valve There are inclined concrete pump 7 sets, often encountered in the process of premature failure of the spool valve, mainly as follows: the injury site is mostly spool valve stem, the stem has different depths and irregular axial Groove, stem movement resistance, the upper and lower can not reach the required position, the valve stem can not be severely affected by movement. At this point must be downtime maintenance, and even to replace the valve stem or valve assembly, both economic and direct impact on concrete pumping work. After the collapse of the general performance of the valve spool: nylon seal severely damaged, broken sand, small concrete blocks, or even pebbles; grease supply pipe top plugging phenomenon. After analysis, may cause the slide valve damage factors are: ①lubrication system failure; ② improper operation (before work or after the end of work empty load is not enough); ③ poor quality of the grease; ④ poor quality concrete; ⑤ spool itself quality Poor; ⑥ slide valve trauma. One of the most likely to cause the slide valve damage, mainly due to lubrication system failure and improper operation. Sliding valve lubrication system is mainly composed of grease box, filter, grease pump, damper, grease distribution valve and grease pipeline. One of the key components is the grease distribution valve. Sliding valve lubrication system failure is that its lubrication point can not be required lubrication or lubrication is not good, but to determine the specific point of lubrication is not good, but also must observe the distribution valve on the grease distribution valve indicator valve and safety valve display rod work , If necessary, need to release the lubrication point interface observation. Lubrication distribution valve by the distribution valve and safety valve, as shown in Figure 2. Its purpose is to distribute the grease from the grease pump to the specified position. When the top of one of the supply tubes is clogged with mortar, the safety valve display sticks out, indicating an abnormal supply of fat. Dispense valve is also equipped with a distribution valve display rod, under normal circumstances fat cycle 1, the display rod action 1 times, if the display rod does not move, that is, the function of the dispensing valve is abnormal. There is a non-swappable feature between the lubrication line and each lubrication point. If you want to fully use the concrete pump in practical work, you should also accumulate more practical experience, continuously improve the proficiency of the operator, try to shorten the troubleshooting time of the concrete pump to pump failure so that the concrete pump can play its due role in the construction Role. Construction Hoist is composed of car, driving mechanism, standard section, attached wall, chassis, fence, electrical system and other parts. It is a manned cargo construction machinery frequently used in buildings. Because of its unique box structure, it is comfortable and safe to ride. Construction Elevator is usually used with Tower Crane on the construction site. The load capacity is 0.3-3.6 tons, and the running speed is 1-96M/min. Construction Hoist,Construction Elevator,Pessenger Hoists,Hoisting Machinery Jinan Shanghangda Machinery Co., Ltd. , https://www.jinanshdmachine.com
Concrete pump in the construction of the right choice