Model LSG Inner and Outer Flow Double Drum Pressurized Screen - LSG

Model LSG Inner and Outer Flow Double Drum Pressurized Screen

I. Performance description:

The inner and outer flow double-drum pressurized screen is suitable for the slit (mesh) preliminary sizing of headbox pressurized screen pulp. The power consumption and equipment floor area are 50% of those of single-drum pressurized screen.

II. Installation Instructions

1. Pour the concrete foundation according to the drawing, preserve the foundation bolt holes and then cure the foundation.

2. Move the pressurized screen to the concrete foundation and align it. Open the screen upper cover and level it with the frame gradienter on the housing flange machined plane before secondary grouting and fixing.

3. The piping should make the pulp inlet pipe, pulp outlet pipe and scum pipe supported by the special pipe bracket other than the pressurized screen; otherwise, the load of screen will be increased. The pipe should not be subjected to any stress.

4. After the horizontal piping of pulp inlet pipe, pulp outlet pipe and scum pipe, arrange the elbow vertically to exceed the height of pressurized screen and then arrange the pipes horizontal or in other directions to make the screen full of pulp.

5. As the concentration of scum pipe pulp is higher than that of incoming pulp, to prevent clogging, connect 1-inch white water or clear water dilution pipe in the front of elbow and valve along the pulp flow at a 45°angle and make the dilution pipe water pressure 0.1 - 0.2MPa higher than that of incoming pulp.

6. Connect the sealing water pipe and clear water pipe to make the water pressure 0.1 - 0.2MPa higher than the pulp inlet pressure.

III. Equipment operation

1. Trial Run

(1) Before starting, wash the lines thoroughly, open the upper cover of pressurized screen to remove the impurity on the screen, close the cover and then rotate the screen pulley by hand for a few turns to ensure there is no abnormal condition.

(2) Open the pulp inlet and outlet pipes and the scum pipe valve to fill clear water and then close the valve after the air is discharged. Connect the sealing water to make the pressure 0.1 - 0.2MPa higher than the pulp inlet pressure.

(3) Operate the pressurized screen motor by push-hold to rotate the screen for short time and ensure there is no abnormal condition before start (the motor rotation should not be reverse).

(4) Start the pressurized screen feed pump and adjust to the operation concentration gradually.

(5) Adjust the pulp outlet and scum port valve to the proper position and make the pulp inlet pressure more than 0.05MPa.

2. Normal Operation

(1) Where the pulp inlet pipe pressure rises or the pulp outlet pipe pressure reduces during normal operation, it indicates the screen drum is clogged. In such cases, shut down the feed pump and pulp outlet pipe valve and then start the pump after a few seconds while observe whether pulp pipe pressure change is normal. If no, stop the machine and clean it.

(2) In the case of scum pipe clogging, open the dilution water pipe valve immediately to dilute until the scum discharge is normal.

(3) Test the motor's operating current. Where the current exceeds the rating, stop the machine and find out the cause.

3.Shutdown Operation

(1) Dilute the pulp in the screen with clear water or white water;

(2) Shut down the feed pump;

(3) Continue filling water to the screen until water flows out of the scum port;

(4) Shut down the screen motor.

IV. Cleaning and Maintenance

(I) Cleaning

1. Clean the pressurized screen in time where clogging occurs.

2. Remove the bolts of screen upper cover, lift and move the cover, rinse the screen inside and take the lump and pulp scum way; remove the drum if the above operation cannot clean the screen.

3. Removal of screen drum: fix the lifting tool to the drum, push the drum out through the set screw, hook the chain block up the drum and lift it out together with the upper drum screen and lift the lower screen drum in the same way out for further cleaning.

4. After cleaning, fit the drums back in turn, place the upper cover in position and fasten the bolts.

(II) Maintenance

1. Check the wear condition of screen mesh (slot) periodically and replace the drum in time.

2. Check the wear conditions of graphite dynamic ring and static ring of the mechanical seal periodically and replace them in time.

3. Frequently check whether the sealing water and rinsing water pressure is 0.1 - 0.2MPa higher than that of incoming pulp; if not, stop the machine and handle the trouble.

4. Replenish grease from the oil hole periodically.