JPH03197704A - Maintenance of mixer in asphalt plant - Google Patents

Abstract

PURPOSE:To efficiently maintain the mixer by detachably installing the mixer to a mixer block of an asphalt plant, and by making the mixer repairable outside the plant after being lowered by means of an elevator and replaced with a space mixer. CONSTITUTION:In execution of maintenance of a mixer in an asphalt plant, front ends of chains 29 for electric chain blocks 28 are hooked in with engaging hardwares 30 of the mixer 12, connection for an asphalt delivery pipe 20 is detached and chains 19 are removed. Bolts and nuts 25, 24 are then removed, the mixer 12 is slightly elevated, allowing mixer support members 23 to be retreated sideward, and the mixer is then lowered, with the chains 29 loosened, toward the underside of a mixer block 5 for enabling the mixer to be carried outside. A space mixer separately prepared is suspended with the electric chain blocks 28 and is placed on the mixer support member 23. The removed mixer 12 is transported to a repair shop for repairing. After completion of the repair work, the mixer is installed again, replacing the spare mixer. Thereby, downtime of the plant can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the maintenance of mixers installed in asphalt plants that produce asphalt mixtures.

[Prior Art] The plant main body of an asphalt plant is constructed by incorporating various devices into a machine frame to form blocks, and stacking these blocks. The lowest stage of the block is the mixer block, which is equipped with a two-shaft mixer for adjusting the mixing of materials. This mixer has two parallel mixing shafts rotating in opposite directions in a mixing tank with a wear-resistant liner fixed to the entire inner surface, and a large number of arms each having a blade are arranged radially on the mixing shaft. It is set up. This mixer section is the heart of the plant main body, and requires periodic parts replacement and repair. For example, at a plant that ships 200,000 tons of asphalt mixture per year, liner blades and seals are repaired twice a year, and bearings, arms, and sprockets are repaired or replaced once every two years. Replacing and repairing these parts is carried out on holidays when plant operations are halted, and skilled workers dispatched by the manufacturer handle the work.

[Problems to be Solved by the Invention] However, when a manufacturer dispatches skilled workers to perform parts replacement or repair work on-site as described above, there are the following problems.

The problems faced by manufacturers include: ■ Since it is impossible to replace parts and repair work in one day off, requests for work concentrate on long holidays. Therefore, it is not possible to equalize the workload, and due to the lack of skilled workers, it is not possible to efficiently handle the workload that is concentrated at one time.

■ Replacing parts and repairing work inside a small mixer is inefficient work, and it is also dirty and dangerous work, which places a heavy burden on the workers.

■ Work must be completed in a short period of time, often requiring overnight work.

■ Labor costs will be high as it will be a continuous construction project.

Problems on the user side include: ■ Parts replacement and repair work can only be carried out when the plant is out of operation for a long period of time. Therefore, parts must be replaced ahead of schedule, which is uneconomical.

■ If there is a plan to repair equipment located above the mixer at the same time, the operation will have to be stopped for an even longer period of time because simultaneous work is dangerous.

■ A complete overhaul is not possible at the plant site. Even if it were possible, it would be necessary to stop plant operation for a long period of time, and construction costs would be relatively high.

There were many problems for manufacturers and users.

In view of the above points, it is an object of the present invention to propose a method for maintaining a mixer in an asphalt plant, which allows mixer parts replacement and repair work to be performed without stopping the plant operation for a long period of time.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a mixer support material for the floor frame of the mixer block placed on a foundation frame, and fastens the mixer to the mixer support material. The mixer is detachably fixed with a tool, and when the mixer is repaired, after releasing the connection between the mixer support member and the mixer, the mixer is supported by the lifting means.

At the same time, the mixer is lowered to a position below the mixer block, and a separately prepared spare mixer is lifted into the mixer block using lifting means and fastened to the mixer supporting material arranged on the floor frame, and the lowered mixer is removed from the plant. The present invention provides a method for maintaining a mixer in an asphalt plant, characterized in that repairs and parts replacement are performed at the same time.

[Function] According to the mixer maintenance method in an asphalt plant according to the present invention, when replacing or repairing parts of the mixer, the operation of the plant is temporarily stopped and the fastening of the mixer fixed to the mixer block is released. Then, the mixer is lowered and taken out from the lower space surrounded by the floor frame of the mixer block while supporting the mixer by the elevating means. Next, a separately prepared standby mixer is raised while being supported by a lifting means, and is housed in the mixer block and fastened and fixed, and the plant operation is restarted. The mixer is then removed from the mixer block and transported to a repair shop far from the plant for overhaul.

In this way, the manufacturer prepares a spare mixer in advance, and when replacing parts or repairing the mixer, the entire mixer is replaced and taken back to a dedicated factory for repair.
Plant downtime can be shortened, and repair work can be carried out efficiently in a factory that is fully equipped with repair equipment and tools. Once the parts have been replaced or repaired, they are replaced using the same method.

[Example] An embodiment of the present invention will be described below based on the drawings.

1 is the main body of the asphalt plant, in which blocks storing equipment according to the manufacturing process are stacked in a layered manner on a foundation 2, and are composed of a vibrating screen 3, a storage tank block 4, a mixer block 5, etc. has been done.

The storage tank block 4 is provided with an aggregate storage tank 6 that stores heated and dried aggregates according to various particle sizes. The aggregate is lifted to the upper part of the plant body l by a hot elevator 7, and is sieved into various particle sizes by a vibrating screen 3 disposed above the storage tank block 4, and stored in an aggregate storage tank 6. A stone powder storage tank 8 is also provided in the storage tank block 4, and temporarily stores the stone powder lifted up by the stone powder elevator 9.

A measuring tank 10 for measuring a predetermined amount of aggregate and stone powder discharged from the aggregate storage tank 6 and stone powder storage tank 8 and an asphalt measuring tank 11 for measuring molten asphalt are arranged in the upper part of the mixer block 5. .

A mixer 12 for kneading various measured materials is arranged below the measuring tank 10. A protruding plate 14 reinforced with a reinforcing plate 13 is fixed to both sides of the mixing tank of the mixer 12, and a large number of blades 16 are supported by bearings 15 placed and fixed on the protruding plate 14. A kneading shaft 17.
The motor 18.18 is rotatably supported at 17 degrees, and the chain 19 is wound around the sprocket fitted on one end of the mixing shaft 17.17' and the sprocket fitted on the motor 18.18 rotation shaft. By driving the kneading shaft 17.17
゛ is rotated in opposite directions. In addition, there is an asphalt supply pipe 2 at the top of the mixer that supplies asphalt.
0 is connected, and a predetermined amount of asphalt measured in the asphalt measuring tank 11 is supplied and injected into the mixer 12 by the pump 21.

A pair of mixer supports 23 are passed between the floor frames 22 of the mixer block 5, and bolts and nuts 24, which are fasteners, are attached.
The mixer support material 2 is removably fastened and fixed by
Projecting plates 14 projecting from both sides of the mixing tank of the mixer 12 are placed on the mixer 12 to support the mixer 12, and are fastened and fixed with bolts and nuts 25, which are fasteners.

Reference numeral 26 denotes a hanging fitting for suspending the electric chain block 28 fixed to the upper frame 27 of the mixer block 5, and an appropriate number of the hanging fittings 26 are arranged according to the size of the mixer 12. Further, the mixer 12 is also provided with a locking fitting 30 for hooking the chain 29 of the electric chain hoist 28 at an appropriate position. The electric chain block 28 is used when suspending the mixer 12 and lowering it from the mixer block 5 by operating the operation switch 31, and may be a manual chain block (and does not need to be kept at all times). It can be prepared when lifting and lowering the mixer.Furthermore, instead of the electric chain hoist 28 that is the means for lifting and lowering the mixer 12, a lift device 32 that can be lifted and lowered as shown in FIG. 4 is used to lift and lower the mixer 12. 33 is a mixer transport vehicle waiting on the ground below the mixer block 5.

Therefore, when repairing the mixer 12, the electric chain hoist 28 is suspended from the hanging fitting 26 of the upper frame 27 of the mixer block 5, and the tip of the chain 29 of the electric chain hoist 28 is attached to the locking fitting of the mixer 12. Stop hanging around 30. Next, disconnect the connection part of the asphalt supply pipe 20, and connect the motor 18, 18' and the cross-wire shaft 1.
7. Remove the chain 19 that connects the mixer 12 to the mixer block 5 so that the mixer 12 can be removed from the mixer block 5. After doing this, the bolts and nuts 25 that connect the projecting plate 14 of the mixer 12 and the mixer support 23 are removed, and the mixer support 23 and the floor frame 22 of the mixer block 5 are further connected. Remove bolt/nut 24.

Then, operate the operation switch 31 of the electric chain hoist 28 to perform hoisting operation and lift the mixer 12 slightly.
The mixer support member 23 is retracted to the side. Next, the chain 29 of the electric chain hoist 28 is operated to let out the first
Mixer block 5 as shown by the imaginary line in Figure 2,
It is lowered from the space created at the bottom of the container, loaded onto a waiting transport vehicle 33, and carried out.

When the work of lowering the mixer 12 inside the mixer block 5 is completed, a separately prepared spare mixer is hoisted up by the electric chain hoist 28 and lifted into the mixer block 5, and the mixer support 23 is returned to its original position and the floor frame 22 is fastened and fixed with bolts and nuts 24, and then the hoisted preliminary mixer is lowered and placed on the mixer support 23, and the preliminary mixer and mixer support 23 are fastened with bolts and nuts.
Fasten and fix with nuts 25. Then, the separated asphalt supply pipe 2o is connected, and the kneading shaft 17.
17° and motor 18. Wrap the chain 19 around the 18° sprocket to complete the mixer replacement. The removed mixer 12 is then transported to a repair shop, where parts are replaced or repaired. Once the parts have been replaced or repaired, the mixer can be replaced again using the same method.

5 and 6, the mixer 12 is detachably attached to the floor frame 22 of the mixer block 5, and the mixer 12 is attached to the floor frame 22 of the mixer block 5.
This figure shows another embodiment in which the robot 2 can be lowered downward.

In FIG. 5, a mixer support 23 made of H-shaped steel is fixed to the floor frame 22, and the mixer support 23 and a protruding plate 34 made of H-shaped steel fixed to the side of the mixer 12 are connected with a slight gap between them. is held, and the connecting portion is reinforced with a reinforcing plate 35 and fastened and fixed with bolts and nuts 36, which are fasteners.

Further, in FIG. 6, the mixer support member 23 having a flange portion 37 formed at the tip thereof is fixed to the mixer 12, and the mixer support member 23 is fixed to the mixer 12.
A flange portion 38 is also formed on the protruding plate 34 fixed to the side of the flange portion 37, and the flange portions 37 and 38 are butted against each other and fastened and fixed with bolts and nuts 36.

Although various embodiments of attaching the mixer 12 to the floor frame 22 in a detachable manner have been described above, the invention is not limited to these in any way (design changes that do not depart from the spirit of the present invention are included in the present invention). .

[Effects of the Invention] As described above, according to the method for maintaining a mixer in an asphalt plant according to the present invention, the mixer is detachably mounted on the mixer block of the plant, and the mixer can be easily lowered by the lifting means. Ok,
When parts are replaced or repaired, the mixer is replaced with a separately prepared spare mixer, and the repair work on the repair mixer is carried out outside the plant, eliminating the need for long-term shutdowns of the plant as in the past. (Parts replacement and repair work on the mixer can be carried out, and mixer repairs can be carried out efficiently in the factory using specialized equipment and tools while having plenty of time.

[Brief explanation of drawings]

FIG. 1 is a front view of an asphalt plant showing an embodiment of the present invention, FIG. 2 is an enlarged view of the mixer block section in FIG. 1, and FIG. 3 is a partially omitted cross-sectional view taken along line A-A in FIG. Fig. 4 is a front view of an asphalt plant employing another embodiment of the elevating means of the present invention, Fig. 5 is an explanatory diagram showing a second embodiment of the structure for mounting the mixer to the mixer block, and Fig. 6 FIG. 2 is an explanatory diagram showing a third embodiment of the mixer mounting structure. l...Plant body 2...Foundation frame 4...Storage tank block 5...Mixer block 12...Mixer 14...Protrusion plate 22...Floor frame 23
...Mixer support material 24.25...Bolt/nut 26...Hanging fitting 28...Electric chain hoist 3o...Locking metal fitting

Claims (1)

[Claims] A mixer support material is arranged on the floor frame of the mixer block placed on the foundation pedestal, and the mixer is removably fixed to the mixer support material using fasteners, and when the mixer is repaired, the mixer support material is After releasing the connection between the material and the mixer,
Lowering the mixer to a position below the mixer block while supporting the mixer using the lifting means, and lifting a separately prepared spare mixer into the mixer block using the lifting means and fastening it to the mixer support disposed on the floor frame;
A method for maintaining a mixer in an asphalt plant, characterized in that the lowered mixer is repaired and parts replaced outside the plant.