我的第四台手机

用了接近九年的第一台手机 NOKIA 6610i 始终撑不到第十年。
还记得，我的第一台手机是在 2005年读中六之前，父母买给我和小弟的。
那个时候，我对手机就只有两个要求，那就是打电话和发短讯。

今晚我打算去 GIANT Plentong 的 YES 手机店买我人生中第四台手机。
为了买新手机，我还特别抓陈霖德陪我，
顺便叫他提供智慧型手机的专业意见，给我参考。

这次我买手机有更多要求：
第一，必须是智慧型手机。
第二，可以上网和拍照。
第三，手机银幕必须要大。
第四，不可以切我的 sim card。

本来我是要买 SAMSUNG GALAXY S3 的，
可是一听到要切我的 sim card 来装进 S3 手机，我就放弃购买S3 手机。

最后我和霖德确定购买SAMSUNG GALAXY GRAND GT-19082 的白色智慧型手机（价钱：RM 1,135）。
霖德提议买这款手机是因为可以装两张 sim card。
而我买这个智慧型手机是因为它符合我对手机的要求。

买手机的第二天，霖德特别来我家 setting 我新买的手机和 装几个 Apps（如：Facebook, WeChat, WhatsApp, LINE, Viber, AVG AntiVirus, QVOD Player, QVOD Merger, Google Chrome, GPS, 和 金山词霸）。

他还教我如何使用这个白色的智慧型手机，还提醒我有什么地方要多加注意。

没想到，几天后，我父母也跟着换新手机。
他们换成了SAMSUNG GALAXY S3 的智慧型手机。

Falling Film Evaporator (FFE)

FFE is the vertical shell-and-tube heat exchanger, with a laterally or concentrically arranged centrifugal separator.

Falling Film Evaporator

A = Product

B = Concentrate

C = Condensate

D = Heating steam

E = vapor

1 = Head

2 = Calandria

3 = Separator

4 = Separator duct

5 = Calandria base

Operation

FFE mostly running under vacuum condition. In most case steam (D) is used for heating the evaporator.

The liquid to be concentrated (A) is supplied to the top of heating tubes (1) and distributed in such a way as to flow down the inside of the tube walls as a thin film.

A thin film enters the heating tube as it flow downwards at boiling temperature. The liquid film starts to boil due to the external heating of the heating tubes and is partially evaporated as a result.

The downward flow, caused initially by gravity, is enhanced by the parallel, downward flow of the vapor formed.

The separation of the concentrated product (B) form its vapor (E) is undergoing in the lower part of the calandria 排管 (5) and separator (3). It is essential that the entire film heating surface, especially in the lower regions, be evenly and sufficiently wetted with liquid. Where this is not the case, dry spots will result that will lead to incrustation and the build-up of deposits.

For complete wetting, it is important that a suitable distribution system is selected for the head of the FFE. Wetting rate are increased by using longer heating tubes, dividing the FFE into several compartments or by recirculating the product.

FFE are highly responsive to alterations of parameters such as energy supply, vacuum, feed rate, concentration, etc.

Advantages of FFE:

1. FFE can be operated with very low temperature differences between the heating media and the boiling liquid,
2. extremely short residence times in the FFE, have very short product contact times, typically just a few second per pass.
3. FFE can be started up quickly

References:

http://www.niroinc.com/evaporators_crystallizers/falling_film_evaporators