Energy-saving Operation in Foundry Kenji SHI OTANI Ishikawa - PDF document

Energy-saving Operation in Foundry Kenji SHI OTANI Ishikawa Malleable CO., LTD Company Profile •Establishment May, 1953 •Capital 48 Millions JPY •President Tetsuo SHIOTANI •Number of employees 134 •Business Casting Sec. (Manufacturing of casting) Machinery Sec. (Machining of metals of casting etc.) Import Sec. (Importing or selling of products made in China)

Production Base Production Capacity: Total Production Capacity 1,600t/ month 7,600t/ month ISHIKAWA Pref., Japan Production Capacity: 6,000t/ month Suzhou City, Jiangsu Province China Site Map Melting: 4t High-frequency induction furnace 2 sets West Factory Molding machine: DI SA230B Production capacity: 1,000t/ month 道 路 Melting: 3t Machine High-frequency induction Factory furnace 1 set East Factory Molding machine: APS (660 x 540) Production capacity: 600t/month

Equipment Specification and Material Constitution in East Factory APS of Shintokogio made (Manufactured in 1984) (660 x 540 x 180 x 180) High-frequency induction furnace Made of Fe 3t/2200kw Casting weight 10kg/flask~ 60kg/flask Number of production items 1,500 items Minimum and maximum number of lot flask per month 5~ 300flask/product Equipment Specification and Material Constitution in West Factory DISA230B (650 x 535) (Manufactured in 2007) High-frequency induction furnace Made of Fe 4t/3500kw 2 sets with 1 power source (Melting, heat-retention) Casting weight 10kg/flask~ 40kg/flask Number of production items Approx. 100 items Minimum and maximum number of lot flask per month 50~ 14,000flask/product

Report on Energy Saving at Our Company  Percentage of CO 2 emissions FY 2011 FY 2012 Electric 95.7% Electric 95.9% Kerosene 2.0% Kerosene 1.8% (Paraffin) (Paraffin) Light oil 0.4% Light oil 0.4% LPG 1.9% LPG 1.9% Percentage of Use Power (Power consumption) 【西工場】契約電力: 4 5 0 0 k W 【東工場】契約電力: 3 0 0 0 k W [East Factory] Contract demand: 3000kW [West Factory] Contract demand: 4500kW Compressor Processing Compressor 3.2 ％ machine Processing 1.8 ％ 3 ％ machine Dust collector Others 2 ％ Others 6 ％ 1 ％ Dust collector 2.2% 7 ％ 造型・ 砂処理 Molding/ 6 . 8 ％ Sand treatment Melting Melting 6.8% 造型・ 砂処理 Molding/ 1 3 ％ furnace furnace Sand treatment 13% 74% 80%

~ Energy-saving Operation~ Productivity Evaluation of Factory (Goal) To set the volume of accepted product (kg/hr) as management target (Production weight (kg) – Rejected weight (kg)) / Operating hours (hr) To clarify about equipment capacity and target of each process To switch the operation mechanism from molding main operation to melting capacity main operation. ☆ How to get the maximum of equipment capability? ~ East Factory Concept of productivity improvement ~ 【 Target of Melting Process 】 4000kg/h (Targeting 1000kg per tapping per 15min) To targeting furnace operation without keeping warm by melting of leaving iron! 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 Melting work/min Electric current (Full power) Tapping Furnace charging Putting crane Completing Completing Control (TP, temp. control at a time control at a time measuring) Slag off Melting of Tapping 1000kg Material charge1000kg leaving iron by high-frequency 3Ton 2Ton induction furnace

Problems  Melting capacity cannot be demonstrated due to variation in pouring weight.  Timing of a tapping call is not clear.  Certainty of quality governing of molten metal is required (control at a time).  Re-checking of cycle time of the molding machine is needed since it does not demonstrate the maximum capability. (It follows the change of weight per flask.) I mproving the above four problems! Unstable Melting Operation due to Variation in Pouring Weight Weight Pouring Molding Tapping Melting Difference in required weight capacity weight capacity melting capacity Operation state kg/flask flask/h kg/hr kg/tapping kg/hr kg/hr Loss of melting heat- 1 5 1 6 0 2 4 0 0 6 0 0 4 0 0 0 1 6 0 0 retention Melting and molding: 2 5 1 6 0 4 0 0 0 1 0 0 0 4 0 0 0 0 full Melting: full, molding: waiting for 3 5 1 6 0 5 6 0 0 1 4 0 0 4 0 0 0 - 1 6 0 0 tapping Leveling this variation to 1000kg is needed.

Re-planning of Process to I ncrease Amount of Molten I ron at Manufacturing Section 時間 位置 製品名 重量 鋳込数 出湯量 7 ：0 0 南 6 4 1 ﾊﾝｶﾞー ① 1 7 . 5 2 0 北 E 0 0 1 0 2 8 1 9 9 0 0 Target Tapping E 0 0 1 0 2 8 1 6 Weight ① 1 7 . 5 2 0 9 0 0 1000kg 北 E 0 0 2 1 ② 2 7 4 ① 1 7 . 5 2 0 北 ② 2 7 2 4 1 0 0 0 ② 2 7 7 ① 1 7 . 5 2 0 1 0 0 0 北 E 0 0 5 0 ③ 2 6 1 7 Challenge for leveling of 8 ：0 0 E 0 0 5 0 ③ 2 6 8 1 7 . 5 2 0 1 0 0 0 melting tapping weight ① ③ 2 6 1 7 ③ 2 6 8 I mproving Measures Against Load of Changing Mold  Using molds of casting small product and large product in turns per tapping is required.  As for mold change of molding machine, two molds can be set by adopting conventional shuttle type (manual operation). However, load is reduced by cylinder due to heavy burden for workers. (But having approx. 20 seconds of molding loss as mold change) Before leveling After leveling Increasing of tapping of tapping Approx. Approx. Approx. 3 times 20 taps/ day 60 taps/ day

大取鍋 待機中 出湯の呼び出しタイミングの明確化 密閉による温 溶解準備完了 度低下防止 注湯準備完了 Visualization of trouble point by ＭＥ Ｋ Ａ 自動 蓋開けタ イ ミ ングに問題 注湯機 standardization of melting, 出湯中 配湯空け替え中 distributing, and pouring works 出湯後 材料投入 I mpact: I mproving of Productivity and I ncreasing of Pouring Temperature  As a result of leveling, improving of productivity is verified.  Productivity: 1558kg/h -> 1655kg/h (Approx. 6.2% up) Furthermore, pouring temperature changes! 1410 ℃ After leveling 1380 ℃ 1360 ℃ Before leveling 1330 ℃ Temperature increase of approx. 30 degrees C. is verified.

Possible pouring time/ tap can be extended by temperature increase though it was 13 minutes before leveling 【 TRY 】 Extending 2 min in possible pouring time Before leveling (Fading 13min) After leveling (Fading 15min) 2 min Production weight: 20kg/flask Production weight: 20kg/flask extension Number of moldings: 40flask/charge Number of moldings: 47flask/charge Tapping weight: 800kg/charge ﾞ Tapping weight: 950kg/charge ﾞ determined Final flask pouring temp.: 1330 ℃ Final flask pouring temp.: 1350 ℃ Effect of heat-retention in ladle and improvement of Mg yield by increase of processed molten metal Variation in Cycle Time of Molding Machine Displaying cycle time in each process of molding-line 0 0 0 0 0 0 158 0 0 0 6 192 632 18.5 18.6 0 0 0 575 17.4 17.5 0 0 0 18.7 18.6 18.7 18.7 0 0 0 18.7 18.3 18.2 3 234 715 18.5 18.6 4 426 5.1 5.2 Control of each process, stop time for molten metal waiting and the number of times of molding-line. Shortening of cycle time and clarifying trouble point