Importance of Boiler Chemicals Water Treatment

Since I have written my experience visiting a boiler manufacturing company recently, I think it is good if I follow up with another article related to boiler. This time, it is about the importance of boiler water treatment chemicals. I remembered monitoring the boiler man blended and poured some chemicals (from Nalco) to be injected into the boilers.

[Flash back: Some of my boiler experience story (explosion) for you to read. Boiler Explosion Part 1 & Boiler Explosion Part 2.]

Do you know that like cooling tower, a boiler also requires chemical treatment for various reasons. When I was a process engineer, I got the opportunity to learn about the chemical water treatments for utility boiler and cooling tower. There are various chemicals with specific functions. The chemicals, which I will explain below will imperatively preserve the life of a utility boiler (in this case a low pressure boiler). A low pressure boiler in this case is one which is less then 200 psi. We shall look upon several chemical parameters, namelu the amines, alkalinity, sulfites and phosphates or polymers of the boiler water.

Amines are used to increase the condensate pH to a range of 7.8 to 8.7. When generating steam, carbonic acid forms and as a result your steam pH is low. Amines are volatile and when introduced into the steam header or boiler water, amines will increase the condensate pH. A low pH will lead to excessive condensate pipe corrosion.

Alkalinity is used to increase the boiler water pH to above 10.5. This serves three purposes. pH above 10.5 will decrease your overall corrosion rates, it will keep a 3:1 ratio of total alkalinity to silica, and it allows the polymer to react with calcium. A 3:1 ratio keeps silica from plating in the boiler. A low pH will result in an over general corrosion appearance on your boiler tubes.

Sulfites are used to remove any dissolved oxygen from the water. Dissolved oxygen enters the boiler in make up water or as air is sucked into the system. Dissolved oxygen is extremely corrosive to your tubes and localized pits will form, ultimately resulting in premature tube failure. Maintain a 20 to 40 ppm residual of sulfite in your boiler water.

Phosphates and polymers are used to react with any calcium in the water. The polymer attaches itself to the calcium. The polymer and calcium then is able to exit the boiler through the surface or bottom blowdown. Phosphate reacts with the calcium and sinks the calcium to the bottom of the boiler. When using phosphates you must perform boiler blowdown daily to release the phosphate and calcium. Failure to use a polymer or phosphate will result in calcium build up on the tubes or as some call it boiler scale. This will decrease the over boiler efficiency and will drastically increase your fuel cost.

It is vital to note that water expands 100,000 times when it change from a liquid to vapor phase. A typical home water boiler 30 gallon system has enough energy to throw a 2,000 pound car over 100 feet in the air if catastrophically failed.

First Image credited to: www.johnstonboiler.com. Second Image credited to http://www.indiamart.com (Example of Nalco Chemical for boiler water treatment).

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Power Failure in Our Industry!

Once upon a time in the Chemical Reaction Engineering Research Laboratory

On a sweet Thursday afternoon (today) when I just started my experiment, a sudden power failure occurred without warning. I was actually in the toilet when the power cut off took place. My wife called and asked, "Do you have electricity there in the lab?". I answered, "We have power here in the lab and I just started my experiment". Then 2 lab assistants walk out from the polymer lab (which is next to the reaction engineering lab) and informed me that the power failure just happened. I was surprised.

Immediately I ran into the lab and discovered that the lab black out. Oh my God!!! This is not good. It's not really about my experiment. It's the Gas Chromatography (GC) which I'm more worried about. The GC is such an important equipment for me and the rest of the students as we use it to identify and quantify our products from the reactor. The GC is very sensitive and frequent power cut-off can jeopardize the equipment and interrupt our research activities. Repairing the GC cost huge amount of money and with limited research budget, we need to do everything to avoid the GC from malfunctioning.

After about 15 to 20 minutes the electrical power resumed. Thank God. I switched it on. I then checked the GC and its PC hoping that nothing will go wrong. When the power failure occurred just now, the oven temperature (of the GC) was 250oC. The standard operating procedure to switch off the GC is when the oven temperature is below 40oC. Sudden GC shut down is not recommended at all. It is strictly a big NO. Luckily the GC works well and nothing seems to be wrong. I restarted my experiment and completed it 3 hours later.

Power Failure in the Plant

The incident reminded me on the power failure that once in a while also occurred in the physical refinery plant I worked in several years ago. Such unavoidable power cut-off from the Electricity Company will firstly trigger chaos within the control room and the entire plant. The supervisor, shift leader and plant operators have to act fast to close all main valves manually from various sections. The flow, temperature and pressure from numerous unit operation equipment such as Niagara filter (filter leaves), deodoriser, packed column, heat exchanger need to be controlled until power resumed. The huge 3000 tonnes per day plant can only be minimally controlled via the PLC which was temporarily powered with UPS (uninterupted power supply) - which provided a few minutes power back up.

Secondly, the power cut off will result in substantial lost and I have to assess and make report about it. Even a milisecond power failure will result in vacuum drop in the plant in result to oil rejection (due to quality off-spec). That also will cost massive lost to the company.

What can we do?

As for my case, in the lab... nothing much can be done. I rest my faith to the God. It's good to install UPS for the GC. If UPS is the answer, then we must have 4 UPS unit in the lab as there are all together 3 GC's and 1 GCMS. However, having UPS alone will not entirely protect this expansive machines. For me, the power company (electricity supplier) must be responsible in providing smooth and reliable power for us (the customers). They should pay all the damage and losses that hit us. Maybe this does not sound like an engineer's solution...

Other option?

A more interesting option is to create and manage our own power system...but can we do it with our resources? I'm referring to solar, wind and frequency (Tesla) energy. I would love to develop one of this power sources AFTER I complete my study. I'll try and do it at my home first... :)

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My Career Progress...

The new year 2010 just arrived but then suddenly January is almost going to end. I'm now in my early second semester for my Ph.D studies and things are heating up. I've just prepared my Ph.D proposal and submitted it to my supervisor. It's now with her for checking.

Ph.D Proposal + Journal Review Paper

At the time, I'm also working on a review paper for my first journal paper. It's very tough. It's not easy reading a lot of technical papers relating to my own research. But, I need to do it. This review paper will be my first international indexed journal paper and I hope it will further boost my spirit and motivation to complete my Ph.D as soon as humanly possible.

Experimental Rig Set-Up

At the same time, I'm also preparing my experimental rig. According to a colleague, it's better for me if I can set up a centralize control system to control all electrical and instrumentation in my experimental rig. Yeah...why not...that's cool... And for that reason, we are going to KL tomorrow to attend a seminar from National Instrument to learn more detail on the control equipment hardware and software. I hope something beneficial and conclusive will be obtained tomorrow. I need to set up my experimental rig as fast as possible.

Quartz Tube Issue

I ordered a set of quartz tube from a local supplier who is importing the quartz tube from London. Unfortunately the quartz tube have not yet arrived. This is not good... At the same time, a company I dealth with from Singapore is offering me quartz tube according to my specification. The bad thing is they quote me such an expansive price. I'm in huge dillema whether to buy or not the quartz tube. My budget is really tiny and I need to spend well, other wise I will run out of money to carry out my research.

Matlab training for Post Graduate Society

Thanks to my fellow friend Nabeel from Iraq who is currently doing his masters in his 3rd semester. He volunteered to conduct a matlab training for us. I'll be confirming few details on the training possibly tomorrow or the day after tomorrow. If God wills, we'll be having the training next week. Only 15 students will be accepted to participate in this 3 days matlab training. I'm definitely attending this training. It is imperative for my thermodynamic analysis study for my reaction, which is going to be projected to fulfil my second journal paper.

Consultation

My headache is not yet over when it comes to the consultancy project i'm currently handling now. I thought everything was almost completed but then suddenly some issue arises, and some modification needs to be done. Yep, it's delayed again. Nevermine, we'll settle it once and for all.

IEM Training Log Book

Last week I received my log book which was checked by IEM representative from Chemical Engineering Division. Luckily the report was ok. Why? I said this because the envelop where the report was in has already torn and was really in bad shape. I can't imagine if something bad happen to my report, then 2 years of my recent engineering experiences are thrown away. Morale: Prepare a back-up of the report incase the report when missing somewhere somehow.

However, the one thing that is nice to see in my report is the comment made by the checker engineer... He recommended me to submit the report for my 3rd year in mid 2010. Why...this is because i've been sending back dated report for my log book. In other words, last year (2009) I submitted my report for 2008. In 2008, I submitted report for 2007. How come this happen...? Basically, the information conveyed was not clear when I enrolled as an IEM member. They say that after registering, I can back date my training experiences. Yes, I can, but the checker engineer at the end of the year will only check for 1 year training experiences only. That's when everything mess up. I did not know about this. Maybe I did not check properly. Haha....It's ok...

IEM project paper

Anyhow anyway, my mentor advised me to use my phd project as the main component to be reported in my final project paper for my professional interview assessment later. I must say that I totallt agree with him. That means, I need to work very hard and efficient for my phd studies. You know what is this...? It's simply killing 2 birds with one stone...Fuhhh....

How about you? Anything interesting you wanna share...? I would love to read you experiences as well...

Before that, check out this video from national instrument Labview...

How Does Actuators Works?

In actuator valve engineering and design, it is essential for engineers, designers, and manufacturers to fully understand the aspects and processes of using this particular product that would eventually help build effective engineering designs in a safe and efficient manner.

One of the most significant products of the company would be the actuators. To make this technical term simpler, an actuator is a device that transforms or converts energy into motion. Also applied as a force, an actuator usually is a mechanical apparatus that takes energy, normally constructed by liquid, air, or electricity, and converts that into a specific kind of motion. This motion can relate to anything from clamping, blocking, to ejecting. These actuators are normally used in industrial applications or in manufacturing, and may also be used in different objects such as motors, switches, valves, and pumps.

From all the actuators available in the market, the most common type would be the ones that are powered by the air, also known as the air cylinder or the pneumatic cylinder. These air cylinders are air tight, usually made out of metal, which uses the energy of compressed air in order to move a piston. In addition, air cylinders are usually used in assembly processes and in manufacturing. On the other hand, grippers, normally used in robotics, use actuators powered by compressed air in order to work similar to the human touch.

Electricity or hydraulics can be a source of power for actuators. Much like there are air cylinders, there are also electric cylinders and hydraulic cylinders where the cylinder converts electricity or hydraulics into motion, and hydraulic cylinders are often used in several types of automobiles. Most of the actuators available have more than one type of power source. For example, solenoid valves can have the ability to be powered by both electricity and air. Electricity powers the solenoid, and the solenoid, powered by air, actuates the valve. Another option for this would be that the solenoid can be powered by both electricity and the hydraulics.

Whether in a linear motion, a rotary motion, or in an oscillatory motion, actuators can still be used, that is if they can create the motion with only one direction, in a circular motion, or in an opposite direction at normal intervals. Hydraulic and air cylinders can also be classified as single acting, which means that the energy source that justifies the movement in one direction, and that a certain spring is used for the other direction. Having these interchanged, these cylinders can act as double as an acting cylinder, which means that the energy is used in two different directions. Even if actuators are usually explained in terms of mechanical implements, muscles are often given as an example of an actuator. Energy, which is created by eating carbohydrates, is converted by the muscle, which in this case would be the actuator, and transform it into motion, such as playing basketball.

The above article was authored by Christel Lumabas who is part of MEA Inc. team. MEA Inc is a world leading organization that is composed of designers, engineers and manufacturers of valves and actuator including butterfly valve, valve actuators, diverter valve, linear actuator, hydraulic check valve and electric actuator for mechanical and electrical automation systems worldwide. For more information check out http://www.meaincorporated.com.

For better comprehension, I include some photos to better illustrate the actuators:

Actuator Diagram - photo adopted from Spirax Sarco

Actuator (topside) connected to one piece ball valve - Image adopted from Randex.

Similar to the latter image, this actuator (topside) is also connected to a one piece ball valve - Image adopted from Ferret.

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Some Problems We Find in A Processing & Production Plant

As a process engineer or production executive, we shall always hope and wish that the plant will be smooth. A processing or production plant will always have a problem whether we like it or not. What will the problem be? Are they thought in the university? Can you get them in the text books? I bet you would not get those valuable informations anywhere there?

So, how can you get them? You'll actually get them when you work and experience those problems yourself. Another way of getting those precious information is by asking and learning it from experience executives and engineers.

I've been working for almost three years in my current work place and I observed all these problems. I think it might be useful if I share all those plant problems with you guys. There are a lot of problems and I shall post it in this blog from time to time. The problems varies and comes from various angles and areas such as (without any particular arrangement):

1. Utilities problems :
power, natural gas, steam, water, chemicals, LFO, diesel, processing aid, air etc. Processing cost can increase the overall production cost.

2. Maintenance & Equipment problems :
Pump, piping, instrumentation, pressure transmitter, level transmitter, temperature indicator, NPSH, cavitation, control valve, steam trap, leakage, insulation.

3. Human resource problems :
Disciplinary, Late coming, absent, failure to obey instruction, negligence, psychology.

4. Report & Documentation problems :
Daily report, monthly report, quarterly report, yearly report, ISO & GMP related documents.

5. Communication problems :
Miscommunication, instruction, network, PC, server, bad relationship with up line, down line and colleagues.

6. Quality problems :
Laboratory, lab checking, quality control, testing error, solution/chemical contamination.

7. Supplier problems :
Raw material - product - goods out of spec, cheating.

8. Supporting equipment problems :
Deterioration of cooling tower performance, heat exchanger performance.

9. Planning problems :
Administration interruption, supply demand, market, margin.

10. Control system problems :
Supervisor Control and Data Acquisition (SCADA), Human machine interface (HMI) and PC, IT, network, softwares.

11. Stock, raw material, storage tank problems :
Network, false information, over flow, insufficient storage tank, contamination.

12. Stress, Pressure & Health Problems :
Meeting deadline, lack of time, inadequate knowledge, 24 hours alert and standby, meetings, reports, various crisis, inability to manage pressure from top management.

OK. That would be some very general and surface introduction on what problems we can expect from running a plant. I'll try to update and add more on those details from time to time. I welcome anybody who want to share problems that they faced in their plant. We can discuss it here and share it with the rest of the readers.

Inside McDonalds Meat Processing Plant

Everybody enjoys having a happy hour meal at the most famous franchise fast food restaurant - "Mcdonalds" and that includes me. In fact, I just had a nice dinner with my family 2 days ago in Mcdonalds Jaya Jusco Johor Bahru. As I googled about processing plant, I found this very interesting short video on how the meat for their famous burgers are processed. It is amazing to learn about their hourly quality control (QC) to ensure that the meat is tasty and juicy before packing it. The cleanliness factor is also strictly taken into consideration. After neatly, safely and cleanly wrapping the boxes (which contains the meat), they're distributed throughout the States.

How To Build Cooling System For Your PC

This is a very interesting video teaches us how to make a cooling system for our PC. We need small and cute heat exchanger, tubing, cooling water, cooling elements, cooling fan, thermal paste, flow meter, pump, cable, elbow, cable holders, header tank, and hard drive cooler. All of these items are related and can be associated with our chemical and process engineering field. Check it out and try it at your PC.

Steam and Vacuum Related Q and A

I received 2 interesting questions at my "Vacuum Dropped Alert" post last June. I think its better for me to answer them in a new post for the benefits of others. I discussed the questions/problems with my colleague at work. I hope Mr Owais and Mr Vinay do not mind we discuss it here.

The first questions from Mr Owais (as adopted from the comment section);

"I'm working as a chemical engineer in GamaLux OleoChemical, Fat Splitting Unit.We're facing the same problem. Our main boiler is under maintenance and smaller one in progress time and again vacuum drop and our production get effected but when we don't have good vacuum then we hold the plant or lower down the feed input and product out put but the main problem is that if we lower down the product Fatty acid flow rate then it get chance to stuck in the pipeline then we have to flush the line which is more troublesome. What will u suggest me about how to solve the problem."

My respond/answer;

First of all, I need more informations in order to answer this issue. What is the design requirement of the steam for the plant to get its vacuum? This should be known from the plant manufacturer or current practice. The steam from the boiler house must be supplied as per the requirement of the plant(s). Maybe your smaller boiler do not produce the same amount of steam as your main boiler. Hence, if your plant vacuum system is fragile, slight pressure drop or fluctuation from the small boiler will trigger vacuum dropped and destroy the oil quality.

As for your fatty acid, you probably need a better insulation for the piping and / or steam tracing along the line. This will prevent blockage in the line (hindering fatty acid from solidifying). Sometimes you need jacketed steam tracing if the product have a lower melting point.

If everything above is not an issue, check your cooling water temperature condensing the steam. Is the temperature low enough as per design. Is the pressure from the cooling tower sufficient? Is the strainer nearby the pump suction blocked?

If everything above is still not an issue, when you stop your plant, conduct a complete air test to check and find any leakages in the vacuum system. I hope I answer your questions.

Example of a fire tube boiler that produces steam for general heating and vacuum system.

The second questions from Mr Vinay (as adopted from the comment section);

"I am working in a textile plant as a maintenance engineer. My steam requirement is about 5500 kgs/hr. The main line from boiler to header is 4 inch. Can a smaller pipeline size lead to water carryover. We maintain TDS level in boiler of about 4000-4500. Our's is a water tube boiler."

My respond/answer;

First of all, I need more informations in order to answer this issue. Is it true your plant need 5,500kgs/hr steam? For me, that is very high. Or maybe your production capacity is very big that it require huge amount of steam. I'm just checking some information/facts...I fear, if you reduce the diameter of the pipeline, the flow rate of steam will be slightly affected/restricted. From my observation/experience, if the boiler deliver water carry over, and the water is still in the line (no where to escape), that means wet steam will occur. This will make the vacuum weak. Hopefully no water hammering takes place!!! That means, reducing the line would not help.

Install some steam trap along the line to eliminate water carry over. Spirax Sarco have a number of good steam traps (I'm not related to them).

I think your TDS is on the higher side. Do your water treatment chemicals work at more than 4000 ppm? Please check with your chemical supplier on this matter. For my case, we control the TDS at 2000, the most 2300ppm. This applies to any type of boiler.

I hope I gave a reasonably acceptable answer/suggestion/comment. If anybody want to further comment or discuss about those two issues, you are most welcome...

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Gaskets

Yesterday, I attended a very interesting and informative training about gaskets. I never imagine that there are a lot to learn and explore about gaskets. After attending the training (delivered by Nipseal), my comprehension on gasket improved and I began appreciating it more. From the training, I know that there are various types and material of gaskets. Prices of gaskets vary a lot and some type of gasket is very tedious and difficult to manufactured/fabricated. Well, what is a gasket? According to Wikipedia, a gasket is a mechanical seal that fills the space between two objects, generally to prevent leakage between the two objects while under compression.

Other definitions/descriptions of gasket:

"A flexible material used to seal components together; either air-tight or water-tight" (PartSelect.com).

"Any of a wide variety of seals or packings used between matched machine parts or around pipe joints to prevent the escape of a gas or fluid" (Staffgasket.com).

Gaskets are commonly produced by cutting from sheet materials, such as gasket paper, rubber, silicone, metal, felt, fiberglass, or a plastic polymer.

Gaskets save money by allowing less precise mating surfaces on machine parts which can use a gasket to fill irregularities. Gaskets are commonly produced by cutting from sheet materials, such as gasket paper, rubber, silicone, metal, cork, felt, fiberglass, or a plastic polymer (such as polychlorotrifluoroethylene). Gaskets for specific applications may contain asbestos. It is usually desirable that the gasket be made from a material that is to some degree compressible such that it tightly fills the space it is designed for, including any slight irregularities.

Gasket is very important in a process plant. It maintains the energy, temperature and pressure in a process system. Selecting a suitable gasket is a must because it does cost money. It is also directly related to the process temperature, pressure, type of medium (fluid or gas) and the chemical properties of the medium.

Another new knowledge that I learned is about spiral wound gasket that can withstand pressure up to 70-80 bar. It is a very interesting and carefully manufactured gasket made of stainless steel. However, I shall elaborate more about this in another post because it is deserve its own post!

OK, let me just explain about the simple/normal gasket. With reference to the left illustration, the gasket is sandwiched between flanges. The property of the gasket and correct compression/tightness allows the process system to maintains it pressure and would not allow oil or gas to leak.

The above illustration shows how a gasket is positioned and locked between those 4 bolts.

Another illustration shows how a gasket is positioned and locked between those 8 bolts.

We install/fix the correct type of gasket before connecting the pipeline with flanges.

The above photo is a very interesting one. It shows the condition of gasket after being used for some time. It is difficult to remove the gasket by bare hands because the gasket sticks very well. We need to use suitable tools to peel and remove the gasket from the flanges. Usually, flanges like this is opened during shutdown to clean/clear pipelines or vessels. After inspection, a new fresh gasket will be used. Never use a gasket twice.

Without a gasket, a 12" butterfly valve like this will leak and spill oil or water and spray gas or steam (depending on your application).

Gasket is not only used between flanges. It is widely used everywhere in a process plant and in our kitchen (the refrigerator). In a plant, gasket can be found in the heat exchanger, valves, vessel man holes etc. The gasket needs to be properly maintained to ensure no upsets in the plant.

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Bypass Line Configuration

There will always be a bypass line in a process plant. However, are you having the correct bypass line set-up? A bypass line set-up is different if the line is used for steam or oil or slurry. If you are using the bypass for a steam line, you can have the bypass line at the bottom of the main line. You must also have a steam trap installed as well on that bypass line to ensure condensate water is released when necessary.

What if you have a slurry line? I was checking my email and found the Cheresources newsletter that tells about this. The bypass lines should be placed above the control valve (as shown in the photo) so that the slurry cannot settle out and build up in the line during bypass. In addition to that, slurry lines should be sloped 1/2" for every 10 feet of horizontal pipe to avoid settling. Actually the steam line should have certain degree of slope to hinder water from settling and further create water hammering which can destroy the pipeline.

Cooling Tower FRP Water Distributor

What you can see in the photo is a cooling tower deck. This is where warm cooling water from processing plant arrives. The warm cooling water will then be evenly distributed on the light blue colour FRP (Fiber Reinforced Plastic) deck by a water distributor. The warm cooling water will then falls underneath the deck through the target nozzle holes. You can see there are plenty of small black round shape holes on the deck. The target nozzles are important to sprinkle the water before it goes further down to increase its surface area (I'll show and explain about target nozzle in future post). The warm cooling water will then be sprayed over a fill in the cooling tower to increase the contact area, and air is blown through the fill. Majority of heat removed from the warm cooling water is due to evaporation. The remaining cooled water drops into a collection basin and is recirculated to the plant (for chiller or heat exchanger). Typically, the temperature drop is 10oC.

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How Do You Analyze Your Heat Exchanger Performance?

I have more than 10 plate heat exchangers (PHE) in my plant. Usually, we'll monitor the flowrate, inlet and outlet temperature, as well as pressure. Before, I joined the company, I observed that the "cleaning in place" (CIP) using caustic solution was carried out when the PHE could no longer produced desired flow rate and temperature outlet. This is one method of eliminating the fouling and scaling on the plate surface in order to improve the heat transfer. If CIP does not work, we have to dismantle the PHE, clean the plates in hot caustic and attach new gasket on it. This will be a far more expensive option and take longer time.

To avoid massive fouling and scaling from getting worse, we have to conduct CIP regularly. When is the right time to perform CIP? As mentioned above, when the flow rate is low or desired outlet temperature could not be achieved, we shall consider doing CIP.

However, I came out with a formula to calculate the "Overall Heat Transfer Coefficient" (U-value) of the heat exchanger. The U-value will give me some indication on which heat exchanger is providing the worse heat transfer. By simplifying the formula in excel file, I can easily know which heat exchanger needs attention just by inserting the inlet/outlet temperature, mass flow rate, heat capacity of oil, and surface area of the plates. The LMTD (log mean temperature difference) will be obtained from the formula and further applied to get the U-value.

I use and manipulated the following formulas:

Q = mc(theta) = UA(LMTD)

Can you work out the formula?

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Food Processing Equipment

I subscribe to a lot of chemical engineering ezine/newsletter and other stuff like equipment/machine processing (to enhance my knowledge - Nowadays knowledge is money!!!). One of them is Genemco (a site dedicated providing information and selling food processing equipment).

Genemco is one of the nation’s largest used equipment dealers with wide selection of high quality used food processing equipment and used refrigeration equipment in stock for commercial and industrial customers. With over fifteen years experience in the food industry, Genemco can help us to design, acquire, or install the food processing or refrigeration equipment we need. No customer or project is too large or too small.

You can subscribe to the newsletter from the Genemco site. Check it out.

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Sodium + Water =

If in case you don't know what happen when sodium (Na), group 1 in the periodic table, is mixed with water (H2O), check out the following short videos.

High-Temperature Heat-Transfer-Fluid Systems

I came across an interesting article from Che.com newsletter. The article caught my attention because it discusses about high-temperature heat-transfer fluid system which is relevant to my plant and work.

Just sharing, the flow of temperature increase in my plant:

1. From feed storage tank
2. Steam heating (50oC) >>
3. Plate Heat Exchanger (105oC) >>
4. Plate heat exchanger (220oC) >>
5. Shell and tube heat exchanger (245oC) >>
6. Oil heater (265oC) >>
7. Plate heat exchanger (180oC) >>
8. Plate heat exchanger (125oC) >>
9. Plate heat exchanger (75oC) >>
10. To product storage tank

The blue Plate heat exchanger and red Plate heat exchanger, shows the same heat exchanger exchanging heat between colder oil and hotter oil.

Shell and tube, and oil heater are able to heat up the oil above 240oC because it uses a closed system steam circulation from a high pressure boiler operating at pressure above 40oC.

Summary of the article from Che.com newsletter:

Fluid selection, system design and maintenance are the keys to achieving the best performance

By Krishnan Sahasranaman - Uhde India Ltd.

Although water and steam are the ideal media for heat transfer, there are often situations when other heat-transfer fluids are called upon to perform this function in the chemical process industries (CPI). Thus there are, at the very high-temperature end, various types of heat-transfer fluids, such as molten salts and even molten metals. At the lower end of the temperature scale we have various proprietary and non-proprietary brines, usually glycols of one kind or the other. Between these two temperature extremes, a variety of heat-transfer fluids are also available. For this discussion, the focus will be on high-temperature heat-transfer fluids; those having useful bulk-fluid-operating temperatures of approximately 70–400°C.

For high-temperature operation, heat-transfer-fluid systems have distinct advantages when compared to steam or direct-fired heating. For example, using steam for process heating to temperatures in excess of 225°C would require steam pressures upwards of 40 bars. For the same application, the use of a heat-transfer-fluid system would thus eliminate the need for costly high-pressure equipment and piping, expensive boiler-feed-water treatment, and specially trained boiler operators. And compared to direct-fired heating, the use of heat-transfer fluids allows the heater to be safely located away from the process and reduces the danger of forming hot spots in the process itself.

An engineer likely to be involved with high-temperature heat-transfer fluids should be familiar with the types of fluids available, and how to choose among them. It is also important to be aware of the design guidelines for the components of a heat-transfer-fluid system, and the problems that can arise with them.

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Leaking Pipeline

There are few things we need to know about our pipeline and our plant process. Pipelines are very important to transfer fluid (eg. oil and water), gas (natural gas and steam), or solid (bleaching earth and other powder form solid). Selecting the right pipeline material, right sizing, right schedule is imperative in ensuring smooth and perfect production operation. Sometimes, we have to be very careful, because, though we have selected the correct material, size and schedule, but unfortunately the supplier cheated and supplied defective pipeline unrealized by us. As a result, the pipeline does not last long as expected. Crack appears and progressively developed into a bigger crack and hole. If oil is moving with some pressure in the pipeline, we can immediately detect the leaking oil when it dropped. It is very clear and if the leak is big, it will be very messy and dirty situation. What if the pipeline is a vacuum line? We can't see anything. We can only detect pressure vacuum dropped in the in the control system via the pressure transmitter installed in the line.

This 12" pipeline has some very small leak that affected the vacuum pressure. The leaking points were covered by another piece of metal to block the holes. However, it still leak (indicated by the yellow sign). Why we cannot weld this line? Explanation can be found below.
Similarly, this 12" SS316 line also has some tiny pin hole which is very hard to see by naked eye. It's impossible to weld the hole because the pipeline is running under vacuum. Any spark will be sucked into the system and will create fire and explosion.

Butterfly Valve

In a production plant, we need a very good process control equipment and system. We learned the theory in a Chemical Engineering subject called Process Control and Instrumentation. It was hard for me to imagine what process control and instrumentation is all about when I studied the subjects few years back.

When I start working in a plant, then everything becomes clear. One of the most important equipment is valve. There are various types of valve. We have butterfly valve, ball valve, gate valve, globe valve, check valve etc. Each type of valve have their own pros and cons as well as functional area. There are a lot of things to talked about valve. However, in this post, I'm going to cover just a little bit about butterfly valve.

The following photos illustrate a typical butterfly valve. It is a 3" Belgium Ventiel (BV) butterfly valve. This valve have created a very serious contamination and lost earlier because it leaks.

A typical butterfly valve. This is a gear type. The gear is used to open or close the disc. The disc is made of stainless steel.

A closer look to the butterfly valve when it is fully open, allowing liquid to flow passing through it. It is now fully open.

The red arrow shows the seat / liner is damaged and worn out. This is one of the reason leakage can occur from a valve. There are various type of seat / liner to choose for different type liquid and process conditions. The disc is half open.

Another angle of the butterfly valve. Extra photo for you to have better comprehension of this piece of equipment.

Later, in coming post, I shall elaborate more about valve. Don't have much time now. Need to go to work.

Plant Process & Oil Lost

While processing crude coconut oil to RBDCNO early February recently, there was some problem. The problem which was not realized by me is that the temperature control was slightly too high. Normally we should control the deodorization temperature between 240 - 245oC. However, the temperature when beyond that, about 246-249oC. As a result, in the pack column, where we are supposed to strip coconut fatty acid distillate (CFAD) via vacuum, some of the refined and bleached coconut oil escape together with the CFAD. Later, we realized that our CFAD tonnage is twice higher than what is normally achieved. That is not supposed to happen, but it does reflect that we are losing some of the refined bleached deodorized coconut oil (RBDCNO).

The price of RBDCNO is far expansive than CFAD. Assuming we lost 20 tonnes of RBDCNO which flows and mixed together with CFAD, and assuming the cost difference between RBDCNO and CFAD is about RM1500/MT; therefore 20 tonnes x RM1500/MT = RM20,000.00 lost worth of RBDCNO. Sadly speaking, that happen just because the temperature control was not within the designated range. Coconut oil easily break off at temperature's more than 246oC, unlike palm oil which can withstand temperature up to 270oC.

Morale of the story, some guidance or working instruction was prepared to be followed. During work/plant operation, we should follow the designated process parameters so that we can achieve our target quality and production.

Learn more about coconut oil here
Learn how coconut oil is produced