1、 Summarization and improvement of concrete-ejecting machines FAN Hua QIULinfeng CHENLingfang Abstract :The text introduces the principle ,style and development process of dry and wet type concrete-ejecting machines. It analyzes domesticand foreign application instance ,allkindsofconcrete-ejecting ma
2、chines mostly merit and flaw. Also it introduces somerepresentational wet con-crete-ejecting machines domestic developed. Some flaws of concrete-ejecting machines are improved. Keywords:concrete-ejectingmachines,frame characteristic ,operating principles , highway. Concrete is the use of compressed
3、air jet, will be allocated a certain level and good water-cement ratio mixing concrete materials, through the pipeline by the jet nozzle, and high speed jet out to the surface by spraying a concrete suppor-t Layer is sprayed concrete construction equipment operations in the main. Asa concrete sprayi
4、ng technology saving concrete and steel, timber, labour-saving and improve construction efficiency and reduce costs, and other characteristics, the concrete applican of the jet increasingly common. Has now been widely us-ed in railway, highway, water conservancy, construction, coal and other buildi
5、-ng works in construction, a tunnel solution, road slope, construction pit, unde-rground works of temporary and permanent care to support the construction m-achinery operations. 1 1 The work of sprayed concrete mechanism and the development trend In sprayed concrete operations, the overwhelming majo
6、rity of the use of concrete-rotor aircraft, such as jet structure is simple, reliable performance, a small, lightweight, easy to operate and maintenance。 Dry jet principle and structure are: the rotor with a liner to a certain speed of rotation, and the combination of pressure plates fixed on the li
7、ner fixed, with a board connected into the wind pipe and discharging elbow, when Rotor equipped with materials in the various materials Cup rotation and into the wind to the elbow and discharging the same time, in the role of gas under pressure, and materials through the elbow and expected to lose t
8、he material transported to the nozzle a nd nozzle in the water Blasting away. Dry concrete jet of the main advantages is a long distance carrier, simple equipment, durable, but because it is so dry nozzles, mixing concrete mixed with water, and therefore the construction dust, are more resilient, dr
9、y spraying operations against workers in the dust Health, in particular the narrow roadway construction, dust pollution is more serious 2。 From the 1960s onwards, in Western developed countries, wet spraying began gradually introducing the technology, all kinds of wet concrete Jets also be developed
10、, sprayed concrete and dry the main difference is that enough (in water-cement ratio requirements should be The volume of) the opportunity to join the mixing of different water。 Wet sprayed concrete is expected lose their access to the former Mixture has added a foot of water mixing, the loser in th
11、e delivery of the cylinder is the wet concrete； dry sprayed concrete is lost in the transmission of the material did not join the mixing Water dry material (ground humidity mixing natural materials or drying materials), and in sufficient volume nozzle before mixing with water, dry mixture and mix qu
12、ickly after the whole wet concrete delivered to the nozzle, speed up the coagulation of the doped Afte r the jet to beam a material of construction 3. At the national level, as peoples environmental awareness and enhance the quality of sprayed concrete requirements of the increase, an increasing num
13、ber of wet concrete into the use of jet aircraft. In recent years, some domestic units also began to develop several wet concrete jet, but the scale of production is still to be expanded. To sum up, jet wet concrete of the main advantages are the following: 1) greatly reduced the plane and next to t
14、he nozzles of dust concentration and eliminate the health hazards to workers. 2) high productivity. Dry concrete Jets general no more than 53 m3 / h, and the use of jet wet concrete, artificial operations up to 103 m3 / h, a mechanical manual, up to 203 m3 / h. 3) The rebound was low. Jet Dry, concr
15、ete rebound of up to 15 percent to 50 percent, the wet spray technical rebound rate can be reduced to below 10%. 4) wet spray, easy to control because of water-cement ratio, a high degree of concrete hydration, it can significantly improve the quality of sprayed concrete and improve quality of the c
16、oncrete absorbed. 2 Wet concrete Jets and the type of work principle Concrete Pumping main piston pump-jet spray and a wet-wet spraying machine screw pump two categories. Piston pump-jet aircraft will be wet plunger-wet concrete as a concrete pump the basic body jet, with the export pipeline to the
17、nozzle and in this Access to compressed gas will jet out of concrete, wet spray such a heavy machine general However, long distance transmission, Second Beach, the Xiaolangdi Water Conservancy Project and other large-scale use of the aircrafts main disadvantage is that low productivity, and screw th
18、e stator sets of wear and tear more serious, there was little scope of application. 3 Domestic wet concrete Jets 3. 1 SPZ26-wet concrete Jets SPZ26-wet concrete jet sent to a gas-rotor aircraft wet concrete, and its working principle of Liwa 280 Ruishi A similar model, by its rotor rotary motor driv
19、en by reducer, the aircraft equipment less investment, high productivi ty, light weight , Good mobility 4. 3. 2 PZ25B Concrete jet aircraft to spray dry, wet spray and spray tide. It automatically clean, non-stick block, cutting speed, little more than expected, h igh efficiency. 3.3 impeller wet co
20、ncrete wet concrete impeller jet aircraft is a new wet spraying machine, it adopted a impeller feeding device, a reliable, long life, to aggregate size of the big advantages. At present, Chinas development of the wet concrete pumping and dual-use spray-spray-wet concrete tunnel construction is indis
21、pensable to engineering equipment, the main impeller and rotor piston-type pumps and wet spraying machine. Impeller and rotor piston wet spraying machine short-distance transportation, displacement of small, fragile pieces of short life, serious leakage pulp, cleaning a long time 5. 4 Jet promote th
22、e use of wet concrete in some of the issues to be resolved At present, due to wet jet technology has obvious advantages, wet concrete Jets in the project is also an increasing number of applications, but because there are some outstanding issues, the wet concrete to promote the use of jet played a c
23、ertain obstacles Role, even in China, currently the main sprayed concrete operations is still dry spray. 1) use of wet concrete jet of liquid condensate, a joint venture of imports and higher prices (up to 6000 yuan / t 8 000 元 / t), and domestic liquid condensate of no production, should be relativ
24、ely dry Spray of powder and quick-setting low price (more than 1000 yuan / t). 2) low labor costs and peoples environmental awareness to be increased. 3) wet concrete jet operations, more complex equipment, operation and maintenance of jet aircraft for less than dry. 4) the use of wet concrete jet o
25、perations, higher equipment investment. 5 Improvement of concrete-ejecting machines 5.1 After the concrete improvement of the characteristics of a jet 1) dust better. The improved use of the seal can not be dust, has greatly improved the working conditions of workers, increased labor productivity. 2
26、) increase the flexibility of high-adhesive rubber material cavity. Concrete can be an effective solution to the problem of bonded easily, remove the concrete to reduce the number of bonded and improve labor efficiency. 3) use of wear-resistant rubber pads. Rubber mats more than double the wear resi
27、stance, a decrease of rubber pads to reduce the frequency of the use of replacement cost. 4) the overall change from the original drive shaft composed of three parts, not easy to solve the demolition, the problem of maintenance. 5.2 Improve the difference between before and after the concrete Jets 1
28、) the original concrete jet rotating body formed by the wear-resistant cast iron foundry, without treatment, after the rust-bonding, improved after the jet cavity spraying anti-rust treatment and greatly reduce the possibility of a bond. 2) the original concrete jet rotation of direct contact with t
29、he material I, Mifengbuyan； feed mouth without sealing device, improved to increase a wear-res istant rubber pads and mouth and feed ring. 3） In rotating body and mouth spray to increase flexible rubber material, and the rotation of the original concrete jet spray and a flexible rubber mouth cavity.
30、 Concrete work of a high-pressure jet of air cavity, flexible rubber in the air cavity under the pressure of being compressed, rotating body is constantly rotating, when the rotation of the chamber passed a flexible rubber pressure zone, the pressure disappeared, flexible Rubber cavity in the stretc
31、h under its own restitution due to the high flexibility of rubber attached to the cavity on the concrete and scattered by squeezing down, automatic removal of the concrete bonding, in order to facilitate maintenance and replacement of the rotating flexible rubber Liu cavity, the overall 12 will be split into four cavity, each of the three cavity. The same token, I expected to increase in a flexible rubber material cavity. 4) the original concrete jet drive shaft for the overall structure, cleaning up the rotating body cavity or replacement work flexible rubber material cavity,
