TAI & CHYUN NEWSLETTER. Product Feature New Type Roller Bearing. October Issue 16 Contents

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1 1 1 TAI & CHYUN NEWSLETTER Product Feature New Type Roller Bearing Bearings are integral part of the collecting plate and discharge electrode rapping systems. Bearing and shaft often wear off after operating for a period of time, and to replace will be labor intensive. T&C supplies new type roller bearings which can easily fit in existing tumbling hammer system and fit any size of shaft. A bearing is an element that constraints the relative motion between moving parts to the desired motion. Bearings are classified broadly according to the type of operation, the motions allowed, or the directions of the loads (forces) applied to the parts. Bearings are integral part of the collecting plate and discharge electrode rapping systems and they come in various shapes and designs. No matter what type and shape of the bearing it is, the function is the same in providing free rotation of the rapping shafts. Constant rotation of the rapping shafts can lead to wear and tear due to shear stress which will affect the alignment of the hammer against the anvil. Issue 16 Contents October 2014 Product Feature New Type Roller Bearing P.1 Upcoming Event Taipei Seminar P.2 Case Study Upgrade of the ESP Rapping System P.3 Trouble shooting Tips Maintenance of the Rapping System P.4 ESP Q&A Session P.5 Announcement SBC, Thailand P.6 CEPSI, Korea P.6 Old type roller bearing is a plain bearing which comprises of just a bearing surface and no rolling elements. Therefore the part of the shaft in contact with the bearing slides over the bearing surface. Bearing and shaft often wear away after operating for a period of time, leading to abrasion and thereby causing the shaft to offset and move downwards. The replacement of the worn out shaft is heavy and complicated, and the cost is usually high. The simplest example of a plain bearing is a shaft rotating in a hole.

2 2 2 Another type of bearing is the sleeve bearing, which got its name from having a single internal rotating cylinder inside it. New type roller bearing is designed because the original design of ESP s CP rapping bearing (old type roller bearing) is subject to wear and tear after operating for a period of time. Worn Out Old Type Bearing The new type roller bearings have two rollers to support the weight of tube and shaft that can effectively reduce the wear and tear of bearing as well as the rapping shaft. For bearing concerns, as well as the whole rapping system, T&C can help redesign and customize to conform to customer s requirement. Spare parts are also available to fit with customer s ESP. Advantages of New Type Roller Bearing: --Tube design can effectively reduce the wear and tear of the bearings and thereby reducing the offset situation --Switching the abrasion of bearing and shaft to the abrasion of tube and pin, thereby greatly reducing the huge maintenance costs --Possesses positioning effects --Customized shaft dimension to conform to the client s needs For more details, please contact our sales representatives or visit us at Upcoming Event 2014 Taipei Seminar On 14 October 2014, Tai & Chyun will conduct a one-day electrostatic precipitator training seminar at Neihu Technology Park Center, Taipei. Key topics that will be discussed include PM2.5 and its prevention, ESP problems in coal-fired power station, ESP operating procedures (Electrical & Mechanical), ESP efficiency enhancement, and ESP case study sharing (Cement/Biomass). For further information please visit our website (

3 3 3 Case Study Upgrade of the ESP Rapping System Application Power Boiler two-field ESP in a Paper plant in Thailand Problem Dust accumulation was found on collecting plates and discharge electrodes due to ineffective CP and DE rapping system. The dust buildup on the CP and DE led to high sparking rate, short circuit and trip of ESP every week. Solution A new CP rapping system design was installed during the ESP internal revamping project done by Tai & Chyun. The new type of rapping system includes the new type roller bearing which can minimize the abrasion of the shaft and bearing due to the weight of the CP rapping shaft and hammer. New DE & CP Rapping System Dust Buildup on CP Carrier Beam / CP&DE The ineffective rapping was due to the long term wear and tear of the rapping shaft and old type bearing. New Type Roller Bearing Benefit Broken and Worn Out Rapping Shaft Longer service life Reduce load/torque on driver motor Reduce and save maintenance job/budget Easy to install and inspect Design with cover to prevent dump of dust

4 4 4 Troubleshooting Tips Maintenance of the Rapping System The normal function of all the rapping systems (discharge electrodes, collecting plates, and gas distribution screen) is crucial to the ESP performance. The breakdown of an entire rapping system or even a single rapper component may lead to inefficient or no rapping, thereby heavy dust buildup on the affected areas. Dust buildup will lead to severe reductions in the ESPs current, inhibit corona formation, increase spark rate and dust re-entrainment, eventually reducing the collecting efficiency of an ESP. The malfunctioning of the entire rapping system is easily detected but on the other hand, the damage of a single rapper is comparatively harder to recognize. Therefore, the maintenance of rapping system is important to optimize the ESP s performance. The ESP rapping frequency is normally set by the commissioning engineer. Rapping hammers at the first field are usually set to rap more frequently due to higher dust concentration as compared to the succeeding fields. Below is an example to illustrate the concept and start point of setting. Users can tune to the optimal frequency from this base. Sample computation: Inlet Dust Loading: 4 g/m3 Gas Volume: m3/hr Dust go into EP = 4 x = 1,200,000 g/hr = 20 kg/min EP Field#1 Collecting Area = 11 m (L) x 2.2 m (W) x 2 x 82 (Passage) = 3970 m2 Assume Field 1 Collecting Efficiency = 70% 20 kg/min * 70% = 14 kg/min Dust Collected in F#1 * 0.01 m * 0.8 kg/m3 = 32 kg 32/ 14 = minutes interval to Rap. Problems Abrasion of the Rapping Shaft For more computation details and troubleshooting tips, please contact our technical support team or sales representatives. Problem Loose Rapping Hammer

5 5 5 ESP Q&A Session Question: By changing rapping hammers angle and sequence, will it help improve ESP efficiency? Answer: Further assessment of dust build should be done first. If the existing angle of lift is not enough to remove the dust, then adjustment should be done. This action will help improve the efficiency in the sense that we are avoiding dust build up which cause suppression of secondary current needed to charge the dust suspended in the gas stream. Question: Besides using heat treatment for rapping hammer, can we use hard facing electrode to buildup the worn out area? Answer: Yes for flat surface and stationary hammer head but this is only a temporary solution. If this was done during maintenance outage, replacement of this worn out parts will be the next step. It will also depend on how serious is the wearing so further assessment is required. Question: Is there any effect, if hammer starts to wear-out? Answer: Replacement of hammers normally takes 3 to 5 years depending on the material used. Worn out hammers are lighter so rapping intensity is decreased and force may not already be enough to dislodge the dust. Question: What to do if the rapping bar is bent? Answer: If the CP rapping bar is bending too much, then the direct replacement is the better practice. If it is not too much bending, a flame scorching on the bent portion and cooling to make it curve back is one of the maintenance counter measures worth to try. Question: We can replace the rapping insulators with plastic? Answer: Plastic insulators are less high voltage withstanding but better flexure strength. Most of tumbling hammer design use ceramic insulator for the rapping drive. Only top-rapping MIGI design apply fiber-glass insulator for rapping. Free Gift Don t miss special gifts from Taiwan You can also be part of us by sending in questions about your ESP or share with us your experiences in ESP troubleshooting. If your question gets published in the next quarter s newsletter, we will send you a special gift from Taiwan! How to send in ESP question: You can send question in your local language by contacting T&C sales representative! Or mail to info@taichyun.com.tw by setting the subject as: Newsletter Marketing Activities as well as providing your name, company name, address and contact number

6 Contact Us! 6 6 Announcement Upcoming Exhibition: We are ready to share our knowledge about ESP technology in the Power Industry. Please come and drop by our booth, our engineers and staff will be happy to discuss with you regarding your ESP questions and concerns CEPSI Korea ASIAN SBC USERS GROUP Thailand 4 th Annual Asian SBC User s Group Venue: Amari Watergate Hotel Bangkok Booth No.: October, 2014 The 20 th Conference of the Electric Power Supply Industry Venue: International Convention Center, Jeju Booth No.: b-01, b October, 2014 International Technical Support Numbers: Indonesia Mobile: +62-(0) Malaysia Mobile: +60-(0) Thailand Mobile: +66-(0) Manila Office: Unit 203-A Bayview International Tower 1, Roxas Blvd. cor. NAIA Rd., Paranaque City Tel: Fax: Mobile: Taipei Office: 10F, No. 250, Sec. 1, Nei Hu Rd., Taipei, Taiwan Tel: Fax: info@taichyun.com.tw Bangkok Office: Na Nakorn Building: No.99/349 Chaengwattana Road, Thungsonghong, Laksi, Bangkok 10210, Thailand Tel: Fax: Website: