Selection of concrete pump for engineering
1. Selection of concrete pump
From mobility, it can be divided into automobile concrete pump, frame pump (without movable boom), trailer mounted concrete pump. From the dynamic form, it can be divided into electric and internal combustion engine type. From the pumping form, it is widely used in China at present there are oblique gate valve and S valve type; the former has the advantage of concrete aggregate diameter wider (40 mm), small motor (75 kW), the low price, only drawback is the pumping height at about 100 m; the latter disadvantage is the aggregate demands (less than 25mm), motor (90 kW), has the advantages of pumping height can reach 150 m or more, but the price is high.
1.2 Type selection
According to the working experience, the construction of large thermal power plants in general with 2 sets of equipment of concrete mixing building (station), 3 sets of concrete pump, one or two trailer mounted concrete pump and more inclined gate valve, in order to meet the requirements of such mobility, aggregate, economy and practicality are
1.3 Selection matters needing attention
(1) primary selection of concrete pump, must first visit the user with a detailed understanding of the actual use of the situation.
(2) The concrete pump for mass production must be selected by regular manufacturers.
(3) try not to choose the first (first batch) concrete pump produced by any manufacturer.
(4) the contract should be signed directly with the manufacturer’s sales department, as far as possible through the intermediate links, so as to facilitate the maintenance service.
2. Commissioning of new pumps
2.1 debugging content before the pump is connected in the factory
(1) personnel composition: technicians, operators, drivers each 1 people, the operator is skilled workers.
(2) read the instructions carefully.
(3) check whether the concrete pump is in conformity with the model in the contract, and whether the certificate number is consistent with the nameplate number.
(4) whether the appearance is satisfied, whether there is leakage or oil seepage.
(5) according to the instructions, the movement times of the piston are determined when the maximum and minimum displacement is measured. For example, the minimum displacement of HBT60 pump produced by Wuhan pump company is 8 + 1 times per minute, and the maximum displacement is 28 + 1 times / min..
(6) check whether the mixing system, cooling system and lubrication system are normal. The truck boom pump must check whether the boom system, outrigger system and the automobile part are normal.
(7) empty load operation 2 hours, check whether the system has leakage, oil seepage, and the pressure gauges should be normal.
(8) check whether all the random spare parts are complete and intact.
All qualified to receive.
2.2 commissioning contents on site before use for the first time
(1) debugging contents of pump connection in repeated factories.
(2) the site of concrete pump should be flat and solid, especially the support of outrigger. Concrete pump as close as possible to the construction site, and consider the exit line after the end of the operation.
(3) arrange and strengthen the conveying pipeline (outer pipe).
(4) empty load operation of 10~20 min, so that the lubrication points are obvious grease.
(5) the middle displacement pump mortar 1~2 m3, when the mortar pump is finished, can be poured into concrete, directly into the normal pumping.
In the test pump, carefully observe the work of each part is abnormal. Such as oil pump, oil temperature, the main pressure gauge changes, the frame pump should also pay attention to the action of the arm and the engine operation, if any abnormal circumstances, should immediately stop, identify the cause, troubleshooting, re examination. After the pump is finished, don’t wash the pump, carefully check whether there is any leakage, oil leakage phenomenon, qualified after washing pump or directly put into use.
3. Pumping skills
The difficulty of pumping concrete (that is, pumping effect) generally depends on the quality of concrete itself, the distance of pouring point, the size of conveying pipe, the distribution of pipes, and the timely elimination of plugging and sudden plugging. (concrete quality has a great influence on concrete pumping effect, but it is not introduced here)
3.1 selection of conveying pipe
According to table 1 the coarse grain size of concrete coarse aggregate table, select the appropriate pipe.
Arrangement of 3.2 external nozzles
The elbows should be used as much as possible, and the worn pipes should be located far away from the concrete pump so as to avoid the burst of high pressure.
Various types of cloth tubes are converted to horizontal lengths (approximate).
3.3 concrete pump plugging removal
(1) once the anti pump is removed, the anti pump switch can be pressed, and the general anti pump running 4~5 strokes can be eliminated.
(2) when the anti pump operation can not eliminate the pipe blockage, it is necessary to open the pipeline as soon as possible and remove the blockage. In addition to cutting off the power, the residual pressure in the pipe must be completely eliminated before the tube is removed.
3.4 Seasonal Construction
3.5 pump operation finished matters needing attention
(1) thoroughly clean the concrete pump and the outer pipe.
(2) check and tidy up random tools.
(3) air transport to 20 min, so that each lubrication point is full of grease.
(4) safe retreat operation site.
4. Daily maintenance
Because there are many kinds of concrete pump, only some general maintenance is introduced here.
4.1 check items before departure
(1) the boom, slide valve and outrigger shall be fully retracted and locked.
(2) the working light and signal device work normally.
(3) adequate fuel, grease and washing water.
(4) the hydraulic oil is enough, and the parts are not leaking.