Existing tower crane safety risks and countermeasures

Tower crane is one of the leading construction machinery industry and civil construction in process of construction. It is due to the large radius of gyration, from lowering high simple operation, widely used in construction, to bring greater benefits to builders in construction technology, quality and progress on. But at the same time, due to the poor management and can not keep up regular maintenance different degrees, the operator and other reasons, the construction will give a serious security risk. Tower crane for construction projects use existing security common problem, proposed approach, we want to project safety management can play a positive role

1. Foundation
A common problem: serious water foundation.
Since the waste water project on the site of corrosive strong, after the water tower on the foundation, material and weld bolt, foundation or cross-section beam etching is strong, casual water, bound to affect the safety of the tower crane. At the same time, water is not conducive to the tower daily bolt, foundation section and the cross beam convergence bolt preload monitoring.
The right way: tower crane foundation should be set up gutters and water wells, while ensuring timely drainage dredge or extraction.
2. Specifications for convergence bolt preload
A common problem: Specifications for Cohesion loose bolts or preload is insufficient.
Tower crane force transmission times depend on the main chord to pass. The main chord force transmitted by the convergence of high strength bolt preload to complete. Mainly the preload force can only assume by the convergence bolt, tower crane consequences not only in the use of the process but also to bear the tensile shear accepted. The convergence of high-strength bolts shear to be poor, so that you can make the convergence bolt break, causing an accident down the tower.
The correct approach: the use of public torque wrench to tighten the bolts, making preload arrive requirements (such as M30 bolt preload 368kN, tightening torque 1800N m?). Daily carry out inspection, we found loose timely tightened. Here demand reminder: the use of high-strength bolts convergence Vice use again after assembly, generally not exceed twice. And respond bolt stop enjoying and reflection task, stops flaw detection, if necessary, qualified ahead may apply.
3. Ashamed pin of the pin set
A common problem: Set the pin is not ashamed standard minor are: 1) to tell whether the pin is too small, 2) pin ashamed not ashamed to tell whether or not enough, 3) welding with wire or pin replacement ashamed, 4) pin ashamed severe corrosion.
Because of the intensity or strength ashamed pin alternatives meet the requirements, ashamed pin in the axial force of the pin, pin ashamed often cut. Not ashamed enough to tell whether or ashamed of the pin in the use of the process is easy to fall, not ashamed pin pin will be in the use of self-detachment, which would cause a serious accident off the arm. If a site Jiayuan use of QTZ80 tower crane folding arm accident.
The correct approach: Set ashamed pin should be strictly according to the instructions to stop arming means, can not be replaced with a smaller size ashamed pin, wire or welding, also check corrosion levels and ashamed ashamed of is not opened before the pin means so as not to add difficulty and safety risks change after the device again. After the device pin requirements ashamed ashamed ashamed of bilateral and should reach 90 °.
4. Installation Safety Limit
A common problem: 1) safety limit is not installed role, 2) insensitivity to install safety limit, and 3) artificially shorted or removal.
Although not previously presented results, but the role of safety limit is not installed, buried a serious security risk. Temporary work overload, causing fatigue metal construction machinery and the life of the tower crane affected.
The right way: tower crane has been tested and its safety has been a fundamental limit installation commissioning qualified operators and other personnel can not arbitrarily stop removal and adjustment. At the same time each day to check on safety limit also be carefully examined.
5. Quality of operating personnel
A common problem: 1) the operator is not high quality, 2) operating without a license.
Since the operator is not high quality, strong sense of responsibility. Tower crane operation so frequent accidents.
The right way: special operations personnel to go through a special assessment, assessment of qualified job front may. At the same time to enhance the supervision of workers. Strictly follow the rules and work, no root certificate for employment.

Energy saving crusher machinery industry propped up one day

The new century, with the socio-economic and cultural development, people's environmental awareness is also increasing, the industry has embarked on the path of development of eco-friendly green as the main mining machinery crusher equipment is no exception. At present, China's mining machinery industry will usher in a relatively large development opportunities.

With the development of the domestic market competition increasingly fierce crusher industry, the development of domestic crusher enterprises increasingly difficult. In the past, China's crushing machines rely on low prices in the domestic market and the world market have been welcomed by customers, it is also a competitive advantage by virtue of this country has become one of the world's manufacturing power crusher. However, China is gradually rising labor costs, which will increase the price of the crusher, Hongxing will slowly lose the price advantage. Therefore, the domestic crusher industry must rely on technology and innovation to find a new way to obtain new competitive advantage.

At present, the world attach great importance to the issue of resources and the environment, how to undermine economic development while maintaining maximum control over resources and the environment has become a major problem plagued countries. This requires the joint efforts of all walks of life and support. Truemax Machinery Co., Ltd. believes the development of energy-saving and environmental protection equipment has become a major task of the crusher machinery, Red Star, who lived to be the first to master the core technology, developed a new type of energy saving crusher, who will be able to gain a competitive advantage. Energy saving equipment for the transformation of domestic crusher has brought new opportunities, crusher industry propped up tomorrow, it can be seen that the energy saving crusher mining equipment for the inevitable future trends.

Asphalt Plant Pavement Distress reason appeared analysis

In recent years the quality of asphalt road as a focus on investment in national infrastructure, local secondary roads, highway, highways, urban roads and other construction projects and a lot of money and limited in the road structure layer thickness design, materials, use of respects the principle of economic resilience, and changes in the volume of traffic, age, etc., and do not focus on. Limited bitumen production scale compliance, can not meet the needs of the domestic construction scale. This makes the inferior part of the asphalt mix of highway construction market, leaving a hidden danger to the road.
Through the layer of oil, the impact of oil on the surface of the adhesive layer in order to make asphalt road base has between itself and asphalt plant pavement layers with good binding, sprinkled through a number of layers of oil and sticky layer of oil is very necessary, However, the construction of which is generally transparent layer of oil by 1.2kg / m2, is mostly due to the current highway flyash cement stabilized graded gravel or crushed stone, permeability than the poor, plus partial extrusion flatness somewhat less , often through the layer of oil product nest phenomenon.
In recent years, due to climatic factors that affect global warming. Temperatures generally increase erratic weather, winter warming continuous high temperature in summer time to grow, whether such weather conditions continue to be test of time, as the temperature increases, leading to softening point is unfit to be lower grade, it is worth considering.
Asphalt concrete mixer design problems of asphalt concrete mixer design according to specifications should go through four stages, namely the target mix design phase, the design phase of the production mix, production mix and test validation phase test shop mix stage, the stage must achieve the purpose of the requirements are clear. During the construction, some two to three units of compression stages, some simply empirically construction, therefore, the presence of a large deviation from the theoretical and practical terms, leading to the presence of the intrinsic quality of asphalt concrete deficiencies, on the other hand, due to the the current national situation caused by the low price plus highway shorter duration, gravel quarry is not standardized, mostly by individual enterprises bear flooring, yard scattered, outdated equipment, material homogeneity and stability are large differences, although most of the units are sampled before the start of the screening analysis done to meet the requirements, but also to detect and to adjust the mixing ratio in the construction machinery process, but because of changes, big differences can not do very accurate, Whetstone than gradation are changing, which is a cause of some common diseases pavement.
Control of asphalt concrete mixing asphalt concrete mixing temperature control temperature control from the perspective of the more stringent specifications for petroleum asphalt mixing factory temperature requirements at 120 ℃ ~ 165 ℃, and in fact some of the construction unit in the mixing temperature control is not so rigorous, high low is very unstable, and some asphalt concrete measurement site pulled nearly 180 ℃, and sometimes less than 110 ℃, the temperature is too high may result in deterioration of asphalt, not sticky asphalt concrete loose, the temperature is too low, the asphalt mix material mixing uneven impact gradation, which also contributed to the local loose asphalt or other diseases sometimes a reason.
Paving asphalt concrete paving of asphalt concrete is relatively large domestic issues, in general two extremes, on the one hand, the requirements of highway paving paving equipment such as full-face or 2000 ABG, on the other hand individually City Department of Transportation or paving equipment used over the past 60 to 70 years of the 20th century, the surface is too narrow, there is no automatic leveling system, complete with the feeling of their experience of the operator for the construction, in fact some of the supervising engineer for two-way highway four-lane highway paving requires full-face, only takes into account the cross slope is easy to understand and eliminate the vertical seams evils are obvious. First, since the section width paving, asphalt from the middle to the sides of the hinge wheel transport inevitably produce segregation due to the large distance, such segregation has changed through the asphalt mix concrete production. Secondly, since the hot flat sides of the cantilever long yearned for a slave, with the increase in the number of paving deformation, but also have a greater impact on the pavement cross slope control. In addition, due to the full-face pavers require larger mixing capabilities, When the mixing station is small, easy to cause the paver open when stopping, so paving the temperature is too low. Impact on the pavement behind the paver is also larger, more vertical and horizontal seaming problems, especially rolling restrictions, is not easy to control all the rolling process is completed within a rolling temperature regulatory requirements, the degree of compaction of asphalt concrete hard reach.

Who's wrong to be jaw Crusher "eutrophication"?

Jaw crusher mineral barren as the world's increasingly serious phenomenon, making sustainable development the use of a variety of metals and non-metallic minerals gradually increase the premise requires processing efficiency is greatly increased, which made crusher equipment higher demand, while the performance of the device is facing greater challenges.


Jaw crusher is widely applied in mineral processing industry, a major impact on processing operations, the jaw crusher ore crushing process materials, mineral rocks overcome internal cohesion between the molecules, the use of mechanical force the material is broken into small particles, In the production process of beneficiation process, jaw crusher is usually divided into two phases of the material crushing, crushing and fine crushing. Mine concentrator, the mine lay crushed material basis for mineral materials sorting operations.

From structural optimization mathematical model hammer crusher, jaw crusher want to frame structure optimization, structural optimization mathematical model must be determined, that determine the design variables, objective function and constraints variables. Design variables in structural optimization design optimization to be changing a set of parameters. Design variables, the more optimized the better, but the problem becomes more complex and difficult to solve larger, so the design variables to be minimized.

Hydraulic cone crusher introduced

Cone crusher is mainly used for metal mining, construction sand and gravel crushing and processing of Sec three sections broken links, because of crushing capacity, production, use HPT hydraulic cone crusher sand production line is used for more river and other aspects of the pebble crushing hard materials.
In addition, HPT hydraulic cone crusher sizes too big iron, sand and gravel in the processing of the finished product 8mm following high levels of grain shape, has great comparative advantage in actual use, the whole production line is stable, grain shape is good, in full compliance with high quality construction machinery sand and gravel production requirements with mechanisms enjoys high praise among customers.

Works
Moving cone cone crusher eccentric leading role in doing Swing movement, led to the broken wall and rolling materials mortar walls squeeze, rub grind, according to the lamination theory, the material in multiple directions by force, according to their texture broken by grinding, stone particles eventually form a stable, consistent with the requirements of the material from the broken wall swing gap whereabouts of the rest of the material continues to break until the final requirements.
Application environment
1, HPT is a new type of hydraulic cone crusher, more secure and stable operation, easy maintenance, downtime is short, the yield is guaranteed, is more suitable for large-scale sand and gravel production systems.
2, HPT cone crusher split multi-point lubrication hydraulic control system, bearing lubrication and overload stronger, so that the degree of automation of the entire production line is greatly improved.
3, HPT cone crusher cavity and stroke for a re experimental design, more suitable for crushing river gravel, basalt, iron ore and other hard materials, spring cone crusher than the average yield increase of 35% -60%.

Crane lift safety knowledge you need to know

With the increase of the construction machinery, all construction machinery are equipped with a crane lift equipment, so today the crane editor tell you how to do maintenance work tower crane equipment.


Safety Tips
a. professionals are not free removable appliances to prevent electric shock or incorrect connections.
b. lift work platforms below overhaul must Diaozhu support the work platform lifts, lifts to prevent a sudden drop in casualties.
c. shall be arbitrarily adjust the relief valve. Each hydraulic system components are working at a predetermined pressure. After any adjustment relief valve may cause abnormal operation of the hydraulic system. Human, machine, material, there will be unnecessary damage.
between any part of the d. the hydraulic system, you must first relief, in order to avoid pressure oil spray, table suddenly decline.

Monthly maintenance
a. wheel, intermediate shafts and bearings, cylinder pin and bearing, boom hinge shaft and bearings for wear.
b. all parts are filling some of the oil, extending bearing life.
c. oil and the oil level of the hydraulic oil. Lifts the whole rises when this position should be higher than the bottom surface of the hydraulic did 40-50 mm. Hydraulic oil is a dark, sticky or gritty and other foreign matter, if found, should be replaced (32 # hydraulic oil).

Year-end maintenance
a. Check all hydraulic lines and fittings. Not damaged pipes, fittings not loose, all joints must be tightened.
b. Remove and disassemble drop valve plunger blowing with compressed air, and then into re-placement.
c. The hydraulic oil exhausted discarded, remove the connector and tighten the oil filter after cleared, cleaned with compressed air, and then back into the tank and piping connection is good.

Concrete mixer concrete preparation necessary tool

Speaking of concrete I am sure you will not feel familiar with it, if you think of a question: Concrete is a mixture made from a variety of materials, is what makes the concrete mixing machine so it evenly? Answer: concrete mixer.


Concrete mixers to complete its composition and mixing can guarantee the quality of its concrete tasks, completely inseparable from its main unit, the first to have a mix concrete mixer drum, of course, the so-called loading, unloading and other institutions are also unable missing.

Concrete mixers can be divided according to the different nature of the various types of mixers, it can be classified according to the type of work is not only the nature, but also in accordance with the principles of agitation, installation, and mix the material tube structure to divide. Of course, there are different types of benefits of different types.

For example, self-loading concrete mixer is stirring a division in accordance with its principles, self-loading mixer rise earlier time it is about just entered in the 20th century when it appeared self-loading mixer. It is conceivable that the structure should be fairly simple, the operation is quite convenient. But it has its own limitations, which mainly for mixing concrete, and those dry hard concrete is required by another rise later mixer - compulsory mixer to complete.

How to make the tower crane is raised?

Tower crane is assembled from standard section made between standard section has a dedicated bayonet fixed to each other. If you are observant, you will find the top of the tower crane there is a height and size of the surrounding sections are larger than standard section of the climb, as the standard section wearing a hat, and with the increase of the festival will climb the tower crane and rise tower rises in fact the whole secret section on this climb.

Tower crane installation process is very complex. First tower needs a solid foundation, after the completion of the tower crane foundation, then the balance of the tower crane boom, boom, cab and other lifting body in the tower, thus completing the initial installation of the tower crane. With the increase of the building, will be higher than is necessary for the tower crane lifting machine plus a festival.

The original section of the climb there is a hydraulic jack, elevated tower crane is relying on top of this hydraulic jack lift. Each standard section of the tower crane has a fulcrum for supporting hydraulic jacks, hydraulic jacks can climb section standard section will rise against himself! Climbing tower crane is a section with increasing height increases when climbing festival height to the height of a standard section when it is vacated between two standard section on the bottom section of space to climb a standard section by repeating the process of jacking plus festival constantly increased.