The structure formation mechanism in wet coal fines briquetting with an active binder

This paper presents the results of studies of the structure formation mechanism for briquettes made from coal fines (sludge, coal dust, and fines), with the use of powdered technical lignosulfonate (100 % Na base) as the binder. It has been established that, when briquetting fine coal fines with active finely-dispersed binders in an air-dry state, the structure formation mechanism of the briquette does not fully align with any of the existing hypotheses. As a result of the research, a theoretical substantiation is proposed for the hypothesis of wet coal sludge briquetting with the use of active finelydispersed binders in an air-dry state. It has been shown that the walls of capillaries and pores in the central part of the briquette experience precipitation from the fluid systems, dissolved by internal moisture, and of coarse particles and a certain amount of the binder entrained in the fluid. Further, a lean fluid advances to the surface of the briquette, consisting mainly of moisture and an excess amount of the active binder, dissolved in it. In the near-surface compacted area of the briquette, the binder is adsorbed on coal particles and the moisture released in the process of thermal destruction and adsorption evaporates. The practical use of the concepts obtained allows controlling the structure formation processes to improve strength without increasing the binder content through layer-by-layer reinforcement of the briquette mass with a closed surface, which significantly improves the process results.

Analisis Coal Plugging Atau Penyumbatan Batu Bara Pada Mesin Coal Feeder Unit 1-4 Dengan Metode FTA (Fault Tree Analysis) Di PT. ABZ

PT. ABZ is one of the big companies that runs its main business in the field of power generation in Indonesia. The company is experiencing problems in one of its equipment, namely coal feeder units 1-4 which often occurs coal plugging or coal blockage. Coal feeder is one of the main equipment that serves to regulate the amount of coal entering the pulverizer. This study aims to determine the root cause of problems from coal plugging or coal obstruction in coal feeder equipment at PT. ABZ using the FTA (Fault Tree Analysis) Method and provides a proposed improvement with the 5W + 1 H Method (what, why, who, when, where and how). Based on the analysis using FTA, it was found that the cause of coal plugging or blockage that occurs in coal feeder machines is due to contamination of the coal used, low calorific value of coal, the machine operates continuously, the machine is old, lack of control from the workers and coal wet when you want to use. Proposed improvements have been made and one of them is by separating wet coal from dry coal automatically using a coal online analyzer. Keyword : Coal Plugging, Coal Feeder, Fault Tree Analysis PT. ABZ merupakan salah satu perusahaan besar yang menjalankan bisnis utamanya dibidang pembangkit tenaga listrik di Indonesia. Perusahaan ini mengalami permasalahan di salah satu peralatannya yaitu coal feeder unit 1-4 yang sering terjadi coal plugging atau penyumbatan batubara. Coal feeder merupakan salah satu peralatan utama yang berfungsi untuk mengatur jumlah batubara yang masuk ke pulverizer. Penelitian ini bertujuan untuk mengetahui akar penyebab masalah dari gangguan coal plugging atau peyumbatan batubara di peralatan coal feeder di PT. ABZ dengan menggunakan Metode FTA (Fault Tree Analysis) dan memberikan usulan perbaikan dengan Metode 5W + 1 H (what, why, who, when, where dan how). Berdasarkan analisa menggunakan FTA, didapatkan bahwa penyebab coal plugging atau penyumbatan yang terjadi pada mesin coal feeder adalah dikarenakan adanya kontaminasi pada batubara yang digunakan, nilai kalori batubara yang rendah, mesin beroperasi secara terus menerus, mesin sudah tua, kurangnya kontrol dari pihak pekerja dan batubara basah saat akan digunakan. Usulan perbaikan telah dibuat dan salah satunya adalah dengan cara memisahkan batubara basah dengan batubara yang kering secara otomatis menggunakan alat coal online analyzer. Kata Kunci: Penyumbatan Batubara, Coal Feeder, Fault Tree Analysis