• factor4 solutions
  • Products
  • Parts Shop
  • Maintenance and Troubleshooting
  • Recruiting Data
  • What's New
  • About MATSUI
  • Global Network
  • Environmental Activities
  • Exhibitions
  • Contact Us

18.Proposal No.2 to achieve 'factor 4' in molding factories

TOP > Environmental Activities > The President's Green Column >
18.Proposal No.2 to achieve 'factor 4' in molding factories

The President's Green Column

Back number :

18.Proposal No.2 to achieve 'factor 4' in molding factories

-Elimination of wastage and troubles with cooling water-

In my previous entry, I explained Matsui's proposal regarding the elimination of wastage of energy in dryers. This time round, I would like to write about how to eliminate wastage and troubles with cooling water.

Wastage & Troubles with Cooling Water

Majority of the molding factories uses water to cool mold and other machineries. This cooling water is being recycled in the factories and is used to take heat away from various part of the factory. However, the heat absorbed by the cooling water needs to be released from the factories in one-way or another.

The below states some ways that heat absorbed by cooling water can be released.

1.Opened Cooling Tower

Most commonly used is the Opened Cooling Tower. However, contamination of water is bad and a large amount is also evaporated. In addition, impurities of water tends to saturate making the water quality unfit for usage. On top of wasting water, it results in forming of scale (see picture 1).

Picture 1: Impurities in cooling water pipes

2.Enclosed Water-cooled Cooling Tower

The Enclosed Water-cooled Cooling Tower can be used to prevent problem from the above. It is widely used in Europe. Since the flow of water remains enclosed, there is no problem of contamination. However, the heat exchanger outside of the factory needs to be cooled with water via evaporation. As a result, it still consumes a large amount of water. The heat exchanger on the outside tends to accumulate impurities and hence, requires regular cleaning and exchange.

3.Centralized Air-cooled Chiller

In order to cool circulating water without evaporating, all water in the factory may be cooled with a Centralized Air-cooled Chiller. The closed circuit prevents contamination and water is not used to cool the cooling water hence, maintenance is not required. However, the above incur high operation cost. While a large quantity of energy is consumed to cool the water, water may be heated again to cool the mold to an appropriate temperature.

Elimination of Water Wastage & Troubles 'Ecobrid'

Matsui would like to propose 'Ecobrid' (see picture 2), an Air-cooled Closed Circuit Water Cooling System that is the solution to all the problems stated above. Not only does Ecobrid don't evaporate circulating water, there is also no trouble over saturation of impurities. Furthermore, heat exchanger on the outside is not cooled with direct contact to water but with fans that leads air to cool the internal part. Thus, there is no need for cleaning or exchanging of heat exchanger.

Picture 2: Ecobrid Cooling Tower

However, the above may not be sufficient to cool water during summer. In the case that external temperature exceeds 30℃, air led in by the fans with be sprayed with mist and vaporized. Vaporization lowers the temperature of the air. For example, when air of 42℃ with humidity of 40% is being sprayed with mist, it can fall to a temperature of 30℃ with humidity of 70%. At such, Ecobrid is capable of providing water less than 25℃~35℃ even in summer. (Illustration 1)

Illustration 1: Adiabatic Cooling

Illustration 2 compares the water and electricity consumption between a regular Opened Cooling Tower and Ecobrid based on field test done by Matsui. According to findings, water consumption is reduced to 1/200 and electricity is reduced by 1/2. In addition, there have been no reports on trouble with water quality nor saturation of impurities in the heat exchangers after 2 years.

Illustration 2: Comparison of Electricity and Water consumption

Energy wasted in the process of cooling water

Ecobrid is capable of providing water of less than 35℃consistently. However, there are cases whereby water of less than 35℃ will be required.

What are our choices then?

In the case where cooling water of 25℃is required for only some lines.

1.Use the Centralized Air-cooled Chiller to cool all the circulating water in the factory

In this case, in parts of the factory that does not require such low temperature of 25℃ will also be fed with the cooled water. There might also be cases that the water are too cold and needs to be heated up. A large quantity of energy is then wasted.

2. Use Cooling Towers (including Ecobrid) to cool all circulating water and use a mini chiller only for the lines that require water less than 25℃.

In this case, energy consumption will be significantly lesser than the case above. However, the chiller installed will be in operation even in winter or when the temperature is cool enough to cool water to less than 25℃. The energy consumed by the chiller to cool already cooled water is being wasted.

Elimination of energy wastage in the process of cooling water 'Free Cooling'

Matsui propose the use of 'Ecobrid', 'Independent Mini Chiller' and 'Free Cooling' together.

In winter or when the temperature is cool enough, Free Cooling would stop the chiller from operating and feed water cooled by Ecobrid and Cooling Towers only.

In other words, the chiller will only operate when water cooled by Ecobrid is above 25℃. Unlike bad water quality from Opened Cooling Tower, water cooled by Ecobrid can be used directly on molds to cool them.

More than 50% of electricity consumed by chillers can be cut down. (See illustration 3)

Illustration 3: Free Cooling of Temperature Controller

'Microgel' a mini temperature controller with the Free Cooling function built-in has already been made available. We are also planning on the sales of the Free Cooling as an option which can be fixed to current chiller and temperature controller.

The 'factor 4' that we are working towards is not merely the elimination of wastage of resources. We aim at halving the resource consumed while doubling the productivity.

In my next entry, I would like to write about Matsui's proposals to double productivity with new technologies for molds of higher functionality.

05 Nov 2009 Hironobu Matsui

Back number :