Slurry vibrating screen!

Our plant’s Texaco furnaces used vibrating screens in coal slurry preparation; these screens were located at the top of the coal slurry tank. Their function was to remove large particles larger than 8 mesh (about 2.38 mm) and to prevent wires and other debris from entering the coal slurry tank. Our factory has been using domestically produced slurry vibrating screens. A vibration motor is used to generate three-dimensional vibrations in the horizontal, vertical, and inclined directions, which are then transmitted directly to the screen to sieve the water-coal slurry. The operating mode and design principles of domestic vibrating screens are primarily modeled after those of foreign Liewell screens, and they have certain shortcomings. These shortcomings become particularly evident after 4,000 hours of operation, posing significant difficulties in production and daily maintenance. The main manifestations are: 1. Limited operational flexibility ； The concentration and viscosity of the coal slurry should not be set too high, otherwise \"slurry leakage\" may occur. Analysis indicates that this is due to design flaws in the coal slurry vibrating screen: the amplitude is low, resulting in insufficient acceleration for the coal slurry ； Particles with a size similar to that of the sieve pores tend to block these pores, and water-coal slurry tends to stick to the sieve mesh ； The coal slurry has high viscosity and inadequate screening, which leads to easy loss of moisture; the dry material forms clumps around the screen and then rolls down through the discharge opening, resulting in waste and increased production costs. 2. Equipment maintenance is difficult, and spare parts are consumed in large quantities ； After operating for 4,000 hours, the vibrating screen began to fail frequently, resulting in almost daily minor repairs and weekly major repairs; the problems manifested as follows: (1) fracture of the eccentric shaft ； (2) The shock-absorbing spring has fallen off or broken ； (3) Fracture of the elastic sieve plate ； (4) The crossbar becomes detached from the sieve box ； (5) Screen tearing. By August 2006, when the vibration screens were replaced, the cost of replacing only the damaged components of the coal slurry vibration screens amounted to as much as 300,000 yuan. Moreover, spare parts such as imported elastic screen plates and screens could not meet the need for timely replacement due to their long supply lead times. 3. It affects the long-term operation of the gasification unit. Due to the tearing of the screens, it is not possible to detect and replace them in a timely manner; as a result, large particles and impurities in the slurry end up entering the slurry tank. Over time, this leads to problems with the operation of the high-pressure slurry pump, fluctuations in the slurry level, and even shutdowns of the gasification furnace. Moreover, after the burners have been in operation for some time, a situation may arise where the pressure differences among the 4 burners are significant. When the burners are disassembled for inspection, impurities such as wires can be found attached to the positioning blocks on the outside of the central oxygen nozzles. 4. Emergency repairs to the coal slurry vibrating screen result in wasted production costs. The emergency repair of the slurry vibrating screen takes at least 2 hours; during this time, the entire slurry preparation system must be shut down and undergo process adjustments. These include a series of process measures such as flushing the low-pressure coal slurry pump and pipelines after shutdown, and conducting a water test run before starting up the system. Throughout the entire process, the workload for the operators is high; the coal slurry accumulated in the cleaning equipment and pipelines results in wasted production costs, and it also causes severe pollution of the surrounding environment. According to statistics, each time a vehicle is parked for washing, around 3 tons of refined water-coal slurry is wasted. To thoroughly reduce the impact of slurry vibrating screens on production, our unit has modified these screens by replacing them with simpler-structured slurry rotary screens. This has resolved the problems associated with the use of conventional slurry vibrating screens, resulting in significant economic benefits. I’m not sure if the moderator is satisfied with the above reply; please point out any mistakes if there are any! This post was last edited by lftyhy on 2009-2-6 11:42]

Above the water-coal slurry storage tank, there is usually a sieve; initially, they were all vibrating sieves, but now some manufacturers or design firms have replaced them with drum sieves. Drum sieves can also be used!

It’s of no use; it only increases the inspection points and workload. There’s no need to go.