Understanding the Extrusion Press as the Conversion Point,
Part 3: Case Study – Billet Taper Quench
如何理解擠壓后的廢料導致更高的成本（III）
案例分析：柱錠梯度水冷
David Jenista, Granco Clark, Inc
David Jenista
INTRODUCTION 引言
In our 2010 paper to the Guangdong Extruder Conference, we discussed the extrusion press as the conversion point of the extrusion process. The value added is converting billet to profile at the press. In 2012 we used the Hot Log Saw as a case study. In this paper we use the Billet Taper Quench as a case study of this concept, showing the benefit of longer billets and how to optimize production with long billets.
在2010年廣東擠壓技術研討會上，我們發(fā)表了一篇論文討論了擠壓機是擠壓流程的轉(zhuǎn)折點。擠壓機把鋁錠轉(zhuǎn)變成型材就是給型材賦予了價值。2012年我們用熱鋸做研究對象。本文中，我們將以“柱錠梯度水冷”作為例，研究在擠壓中短錠將能帶來什么效益，如何使用短錠優(yōu)化生產(chǎn)。
REVIEW回顧
In 2010 paper, we provided the following summary of the financial considerations associated with the extrusion plant:
1.There is a large cost associated with owning a press line. This cost falls on the PROFILE because the profile has the added value.
2.There is an operating cost for the extrusion department that also falls on the profile, because the profile is the only source of revenue. So the profile yield is very important to maximize the economic result.
3.The cost of the other departments and the company profit is also covered by the profile selling price. This cost may be more than the entire cost of the extrusion department (#1 and #2 above).
4.Decisions must be focused on the maximum shippable Kg/Hr to spread all of the cost over the most products.
在2010間的論文中，我們提出了運營鋁型材擠壓廠所要考慮的一些經(jīng)濟因素，總結(jié)如下：
1.擁有一條擠壓生產(chǎn)線要投入巨大的成本，投入成本需要靠型材的售出來平衡，因為型材自身具有了價值。
2.擠壓部門的運營成本也需要靠型材的售出來平衡，因為型材是收入的唯一來源。所以，型材的收益對于經(jīng)濟效益的最大化至關重要。
3.公司其他部門的運營成本和公司的利潤同樣依賴于型材的售價，這項開支可能多于整個擠壓部門的所需成本（上述1、2兩點）。
4.做決策時必須以單位時間可供發(fā)貨產(chǎn)品量Kg/Hr最大化作為核心目標，盡可能地做到最多的產(chǎn)品的成本比。
CASE STUDY 案例分析
For direct extrusion presses, temperature tapering of the billet can provide significant increase in press speed without reducing profile quality and in some cases improving profile quality.
對于正向擠壓機來說，短錠溫度遞減卻能使擠壓速度明顯提高，不會影響型材的質(zhì)量，一些時候還會提高型材質(zhì)量。
Taper heating of the billet with an electric induction billet heater is a common practice, but the equipment is not easily and accurately adjustable for different profiles and billet lengths. import suppliers of electric induction heaters can provide a precision gradient but these units are very expensive to purchase.
用工頻爐對短錠梯度加熱是常見的做法，可是對于使用它們不是一件容易的事，尤其是要針對不同的型材和對于不同的長度的短錠需要做精細的調(diào)整。盡管進口工頻爐的供應商可提供一個精確的溫度梯度，但是要購買這些設備十分昂貴。
Electric cost causes many extruders to choose gas heating. The benefits of gas heating can be combined with the Billet Taper Quench to provide billets with a precise temperature taper.
電耗成本高也引發(fā)很多擠壓機選擇使用天然氣加熱。天然氣加熱的好處即結(jié)合使用柱錠梯度水冷裝置可向短錠提供精確的溫度梯度。
The Granco Clark Billet Taper Quench provides accurate temperature tapering with adjustment from the operator console.
格蘭克克拉克梯度水冷裝置可通過設備操作臺提供精確的調(diào)整溫度梯度。
Figure 1.Taper Quench processing a billet
圖1 梯度水冷處理短錠
TECHNICAL CONSIDERATIONS技術考量因素
The direct extrusion press design is the most popular design because it is simple to produce, operate and maintain. The continuous extrusion model with welding dies functions well with puller systems and other automated handling equipment.
正向擠壓機是普遍采用的設計，因為它易于生產(chǎn)加工、控制使用和維護保養(yǎng)。它可擁有一個連續(xù)擠壓的模式，因為有柱錠焊接技術，還有牽引系統(tǒng)和其它自動化的擠壓配套設備。
But the direct extrusion press has a thermodynamic problem. At the beginning of the cycle, the aluminum in the press container is too cold and at the end of the cycle the aluminum is too hot. The temperature change is caused by the friction in the container and the flow stress of the aluminum. The result is the aluminum is difficult to push through the die at the beginning of the cycle and the extrusion speed must be reduced at the back of the billet to prevent defects.
但是正向擠壓機也存在一個熱力學的問題。在擠壓循環(huán)開始時鋁錠在壓缸內(nèi)太冷，在循環(huán)末尾時鋁錠又變?yōu)樘珶?。在壓缸?nèi)的摩擦力和鋁錠的流變應力引起溫度變化。其結(jié)果是，在擠壓周期開始時鋁錠難以被擠壓通過模具，鋁錠后部的擠壓速度必須被降低，以防止擠壓出廢品。
Extruders are always seeking ways to improve production capacity. One method that extrusion press suppliers can offer is a press with a longer container. The longer container increases the ratio of live-cycle-time to dead-cycle-time, increasing the production capacity of the press. Twenty years ago the standard for maximum billet length from most extrusion press manufacturers was 400% of the billet diameter. For example, a press designed to process a 178mm billet would have a container that was 710mm long. Now imported extrusion presses will have containerswith billet lengths that are 500% or greater. It is common to see a specification for a 950–1000mm long container for 178mm billet.
擠壓機一直在尋求方法來提高產(chǎn)能。擠壓機供應商提供的一種方法就是提供一種長壓缸擠壓機。長壓缸增大了擠壓時間和非擠壓時間的比率，提高了擠壓機的產(chǎn)能。二十年前絕大多數(shù)鋁擠壓制造商的標準是最大的短錠長度是短錠直徑的400％，例如，設計一擠壓機擠壓178毫米的短錠需要一個710毫米的壓缸，現(xiàn)在進口的擠壓機的壓缸長是短錠長度的500%或更長一些，對于178毫米的短錠一般采用的是950－1000毫米規(guī)格的壓缸，已普遍可見。
This change is good for increasing the productive time of the press but it increases the natural thermodynamic problem with the direct extrusion press. The longer billet results in more container friction and increased heating of the back of the billet. So the benefit of tapered billets is even greater with a modern imported extrusion press.
增加了擠壓的生產(chǎn)時間這一變化是好的，但也增加了正向擠壓的熱力學問題。短錠越長導致壓缸產(chǎn)生更大的摩擦，使得短錠后部的熱度提升，使用現(xiàn)代的進口擠壓機可得到更好的短錠梯度降溫的好處。
With an imported extrusion press, the extrusion speed increase will be 20% to 30% for many profiles. In our testing we found that the most difficult profiles will give the largest increase in speed.Many profiles with thin walls using industrial alloys will have speed increases much greater than 30%.
對于很多型材使用進口的擠壓機可提高擠壓速度20－30%。在我們的測試中，我們發(fā)現(xiàn)絕大多數(shù)難以擠壓的型材在擠壓速度上都有極大的提高。很多采用工業(yè)鋁合金薄壁的鋁型材的擠壓速度已提高了30%。
When combined with a Granco Clark “Hot Jet” gas furnace, this taper quench solution is less expensive to purchase and lower cost to operate than an imported electric induction heater with precision taper heating.
當與格蘭克克拉克熱噴射燃氣加熱爐一起使用時，其梯度水冷解決方案要比具有精確梯度加熱的進口工頻爐的購買價格便宜，運營成本更低。
The Granco Clark Taper Quench has the following features and specifications:
The Taper Quench is located after the billet furnace and before the press loader.
The unit provides temperature gradients of up to 140C0.
The variation of the taper is less than 10C0.
The operator can select which portion of the billet will be tapered.
Quench does not limit the throughput of the system.
格蘭克克拉克梯度水冷具有特點規(guī)格如下：
梯度水冷裝置安裝在柱錠加熱爐之后和短錠輸送臺之前。
梯度水冷可提供了高達140 C0的溫度梯度。
梯度變化范圍在10 C0之內(nèi)。
操作員可選擇對某部分的短錠進行溫度梯度遞減。
淬火沒有對系統(tǒng)的生產(chǎn)能力有任何限制。
FINANCIAL CONSIDERATIONS經(jīng)濟考量因素
The most important economic issue is the higher production rate. The added benefits of reduced profile defects and protecting the extrusion die from overheating are not calculated in this financial analysis.
最重要經(jīng)濟的問題就是更高的生產(chǎn)率。減少型材次品和保護過熱的擠壓模具的效益并沒有計算在本財務分析中。
This is an example of the calculation for the costs of profile production:
Profile cost per ton:
The cost of profile productionis from the 2010 Conference paper. The profile cost is dependent on production rate, so our assumptionwill be 1.2 ton/hr and 6000 hr/yr production time.In the 2010 conference paper, our sample showed the cost of ownership was RMB 1200/hr, the cost of overhead was RMB 660/hr, the cost of operation was RMB 1000/hr.
1.Cost of ownership: RMB 1200/hr÷ 1.2 ton/hr = RMB 1000/ton
2.Cost of overhead: RMB 660/hr÷ 1.2 ton/hr= RMB 550/ton
3.Cost of operation: RMB 1000hr÷1.2 ton/hr = RMB 833/ton
Total Cost: RMB 2383/ton
下面是有關型材成本的計算：
每噸型材成本：
我們2010年研討會的論文中有提到型材的成本問題。型材成本是根據(jù)生產(chǎn)率來定，生產(chǎn)率我們假設為1.2噸/小時和6000小時/年生產(chǎn)時間。2010年研討會的論文中我們例題顯示的是生產(chǎn)線投資成本1200元/小時，間接成本是660元/小時，運營成本是1000元/小時。
1.生產(chǎn)線投資成本： 1200 元/ 小時÷1.2噸/小時 = 1000元/噸
2.間接成本： 660元/ 小時÷1.2噸/小時= 550元/噸
3.運營成本： 1000元/ 小時 ÷ 1.2噸/小時= 833元/噸
總計：2383元/ 噸
Please note that this cost is the cost if the factory has excess capacity. If the factory production is full then the cost must also include the cost of lost sales. Studies have shown that this cost will be 2 to 3times greater because the entire gross margin of the value added in all departments is lost when the order is lost.
需要注意的是，我們這里提到的成本投入前提是工廠有超額生產(chǎn)能力。如果工廠生產(chǎn)能力是滿負荷的，那成本投入還必須包括銷售機會喪失的成本。研究表明該成本會增大2到3倍，因為整個公司的毛利潤將會因為訂單的丟失而損失。
In this example, if the Taper Quenchimprovesthe net press throughput by 15% then the resulting cost per ton would be:
1.Cost of ownership: RMB 1200/hr ÷ 1.38ton/hr = RMB 870/ton
2.Cost of overhead: RMB 660/hr ÷ 1.38 ton/hr= RMB 478/ton
3.Cost of operation: RMB 1000/hr ÷ 1.38ton/hr = RMB 725/ton
Total Cost: RMB 2073/ton
此例中，如果梯度水冷將提高純擠壓產(chǎn)量15%，那么每噸成本結(jié)果將是：
1.生產(chǎn)線投資成本：1200 元/ 小時 ÷ 1.38噸/小時 = 870 元/噸
2.間接成本：660 元/ 小時 ÷ 1.38噸/小時 = 478元/噸
3.運營成本： 1000 元/ 小時 ÷ 1.38噸/小時 = 725元/噸
總計：2073 元/ 噸
The example result is a RMB 310/ton (RMB 2383/ton – RMB 2073/ton) cost reduction. If the three year production is 24,840 tons (6000hr/yr╳1.38 ton/hr╳ 3yr) then the payback for the taper quench is RMB 7,700,000.
例題的結(jié)果是每噸型材可降低成本310元（2383元/ 噸－2073元/ 噸）。如果3年的生產(chǎn)是24,840噸（6000小時/年╳1.38噸/小時╳3年），那么梯度水冷的投資回收將是770萬元。
The calculation for each company and each factory will be different, but the example above can be used as the template to make the calculation for the individual situation.
每個公司和工廠的計算方式可能會不一樣，但是上述例證可以作為一個模板，結(jié)合個體具體情況來加以計算。
SUMMARY 結(jié)語
The extrusion press is a valuable resource and highshippable kg/hr is required to achieve financial success. This must be considered in all equipment and process decisions.
擠壓機是寶貴的資源，高交貨量公斤/小時是實現(xiàn)財務上的成功所必需的。在做有關設備和工藝的決策時，這是必須都要考慮在內(nèi)的。
