Low density cleaner

Brief Technical Description of the Low Density Cleaner

The Low Density Cleaner is mainly used in the pulp preparation sections of deinking lines for cultural paper, OCC pulping systems, and chemical thermal mechanical pulp (CTMP). The pulp enters the cleaner tangentially, generating centrifugal force that separates heavy contaminants from the pulp.

Clean pulp concentrates at the center of the cleaner and flows toward the accept outlet at one end. Light contaminants in the pulp—such as air or other materials lighter than fibers—also gather in the central vortex and are separated in the same way. Light contaminants can be discharged from either end of the cleaner.

Heavy contaminants move downward along the helical inner wall (HELIX spiral) in the upper section of the cleaner, then accelerate through the lower cone (T-cone) and finally exit through the reject outlet.

Low Density Cleaner – Equipment Overview

The ZCF/TSC series heavy-duty cleaners are forward-flow hydrocyclones designed to remove large-sized contaminants from pulp based on the vortex principle. They feature high removal efficiency, low fiber loss, and enhanced cleaning performance, thereby improving the overall quality of the pulp.

Low Density Cleaner – Working Principle

The ZCF/TSC heavy-duty cleaner operates using the principles of vortex centrifugal separation. It utilizes the difference in specific gravity between contaminants and the fibers/water in the pulp, relying on centrifugal force generated within the vortex to separate them.

As shown in Figure 1, under a certain pressure, the pulp enters the upper cylinder of the cleaner tangentially at a high velocity. Driven by the inlet pressure, the pulp flows downward in a spiral motion along the inner wall of the cleaner. Heavy contaminants in the pulp are thrown toward the cylinder wall by the centrifugal force generated by the swirling motion and move downward along the wall until they are discharged from the reject outlet at the bottom of the cleaner.

Meanwhile, the fibers and water gradually move toward the low-pressure zone at the vortex center during the swirling process. They then move upward in a spiral along the center of the cleaner and are discharged through the accept pipe extending into the vortex center.

Low Density Cleaner Equipment Parameters

	ZCF/TSC400	ZCF/TSC450	ZCF/TSC600
Single cleaner accept flow rate (L/min)	400	450	600
Inlet consistency (%)	0.1-2.5	0.1-2.5	0.1-2
Inlet pressure (Bar)	2-4	2-4	2-4
Accept pressure (Bar)	0.8-1	0.8-1	0.8-1
Pressure drop between inlet and accept (Bar)	1.2-2	1.2-2	1.2-2
Maximum operating temperature (°C)	<60	<60	<60
Backwash water flow rate (L/min)	40±10	45±15	60±20
Maximum backwash water consistency (%)	0.6	0.6	0.6
Backwash water pressure higher than accept pressure (Bar)	0.5-1	0.5-1	0.5-1

Photos of the installation site