Cooling and finishing of steel pipes

First, cooling of steel pipes
After the steel pipes are sized, they will be transported to the pre-finishing area through rollers. The first process of the finishing line is cooling, which is carried out on the cooling bed. The cooling beds are chain cooling beds, rack cooling beds, spiral cooling beds, and step-type cooling beds. Our factory uses a step-type cooling bed, which has the following characteristics:
(1) Uniform cooling;
(2) Less damage to the surface of the steel pipe;
(3) The pipe can rotate in the same tooth to obtain maximum straightness.
The length of the step-type cooling bed is 58 meters and the width is 34 meters. The bed surface is tilted downward with an inclination of 2.78°. The cooling bed is divided into four parts along the width direction, and each part has a set of lifting and translation devices. A water cooling device is provided at the end of the cooling bed to cool the thick-walled pipe. After cooling, the temperature of the pipe is lower than 80℃.

Second, the cooling bed structure:
1. Rotary arm conveyor: The pipes coming out of the sizing machine are transported to the front end of the cooling bed through the roller conveyor, and then the pipes are sent to the cooling bed for cooling through the rotary arm steel transfer machine.
2. Bed
The cooling bed includes a moving frame of a welded steel structure, a fixed frame of a welded steel structure, and a lifting and transferring device for the movable beam. The moving frame and the fixed frame are respectively fixed with racks.
When the lifting drive motor drives the eccentric shaft to rotate, the stepping frame moves up and down through the connecting rod and the pull rod, thereby driving the stepping beam to move. Because the swing rod is driven by the eccentric shaft and the movable frame is in rolling contact, it can be ensured that the movable beam has only lifting movement and no translational movement during the lifting drive process. Similarly, when the lateral drive motor drives the eccentric shaft to rotate, the swing mechanism is used to make the moving frame move horizontally through the connecting rod.
3. Arm-type dialing machine: After the steel pipe is cooled, it will be sent to the rotary feeder of the water cooling tank through two arm-type dialing machines on the inclined grate at the end of the cooling bed. The arm-type dialing machine is operated by a hydraulic cylinder.
4. Water cooling tank: When the steel pipe has been cooled to below 80℃ on the cooling bed, there is no need for water cooling. At this time, the steel pipe directly passes over the water cooling tank through the rotary feeder (as shown in Figure 8-6). For steel pipes that have not dropped to the required temperature after passing through the cooling bed, they will enter the water tank for cooling. At this time, just rotate the feeder in the opposite direction.
5. Steel pipe dropping mechanism: To make the pipe drop to the pipe row collection stand for pre-finishing sawing after water cooling, a set of steel pipe dropping mechanisms is installed behind the water cooling tank. The mechanism is an easy-to-drop hydraulic lever system:

The steel pipe will move automatically to the fixed beam of the first-level descending mechanism after leaving the water tank, and then be received by the movable beam of the first-level descending mechanism. The first-level descending mechanism drives all the movable beams to move under the operation of the hydraulic cylinder, and sends the steel pipe to the fixed beam of the second-level descending mechanism, and then sends the steel pipe to the pipe row collection stand through the same action. When the steel pipe is sent to the fixed beam of the second-level descending mechanism by the first-level descending mechanism, the steel pipe is tilted due to the different descending heights in the length direction, so that the residual water in the pipe is discharged. However, when it is sent to the collection stand through the second-level descending mechanism, the descending height of the steel pipe is restored to balance in the length direction due to the structure. In this way, the steel pipe can enter the finishing sawing area very stably.

Third, the technical performance of the cooling bed:
Cooling bed type: walking beam type
Length: 58 meters
Width: 34 meters
Number of teeth: 164
Tooth pitch: 350 mm
Walking beam spacing: divided into three sections. The first section (5 meters long): is 500mm; the second section (21 meters long): is 1000mm; the third section (32 meters long): is 2000mm.
Starting 2m rack beam: cast iron plate
Stepping beam transmission: electrical-mechanical transmission
Pipe discharge: easy-to-drop lever system
Stepping cycle: about 15 seconds
Lifting motor: 4 units 100KW 1100rpm DC
Translation motor: 4 units 22KW 1600rpm DC