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Book Review: Little Bets, How Breakthrough Ideas Emerge from Small Discoveries

Rifka Aisyah Leave a comment

Weekend is almost over. So let’s begin new week with new insight. Instead of sharing chemical engineering things which may be quite serious, in this post I want to share you a book I read. The title is Little Bets – How Breakthrough Ideas Emerge from Small Discoveries by Peter Sims.

I just read second chapter of the book of ten chapters. So I am quite slow at reading. That is because content in second chapter is really amazing. I highlighted most of the chapter and I internalized the chapter. Problem I always face after reading good book is I forget the content or I don’t know how to behave better based on the book. So, here I write it so it will lessen my forgetfulness.

Title about second chapter is The Growth of Mind-Set. I kept repeating word “growth”, “grow”, “growing” to myself and I visualized is as growing small tree. This chapter is really important for me. Read More

Methane number empirical models

Understanding Methane Number

Rifka Aisyah 1 Comment

In my previous LNG project, we need to supply gas with specified minimum methane number and specified higher heating value.

What is methane number?

It is the measure of resistance of fuel gases to engine knock, known as detonation. Detonation is produced by the auto-ignition of fuel/air mixture ahead of the propagating flame. Detonation must be immediately stopped to avoid increase of wear and tear and engine damage.

If MN is too low, the detonation can reduce engine efficiency and increases the quantity of harmful engine emissions.

MN Calculation

I searched if there is formula for the calculation, but I cannot find it. MN is not gas thermodynamic property, so no equation of state can be used to calculate it. I found there are several online methane number calculators. I tested three of them, Cummin, Wartsilla, and DNV MN calculator, respectively by using LNG Tangguh composition. These are the results.

Read More

Natural Gas Quality Designation Parameters

Rifka Aisyah Leave a comment

When I was working on my second EPC project in Senoro, which was gas processing facility, I read that there are several natural gas quality that shall be complied. In the project, we also had to guarantee that the facilities can process gas from wells so that it met requirement as stated in contract. In this post, I want to share you the quality designation parameters for natural gas. To understand more about this area, please check ISO 13686: Natural Gas – Quality Designation.

Natural gas quality designation parameter
Natural gas quality designation parameter

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Centrifugal Pump Sizing Spreadsheet

Rifka Aisyah 4 Comments

Since past two days, people still celebrate new year, so office activity has not started yet. That means I actually still in holiday too. But I want to update this blog while enjoying my holiday. I cannot (or in a mood) to create full article. So, instead sharing full article, in this post, I want to share you centrifugal pump sizing spreadsheet.

I created pump sizing spreadsheet for my first LNG project. The inspiration came from Pump Sizing Calculation from CheCalc. But I made it better.

I think you should download this spreadsheet because it offers better features that online calculation fro CheCalc. 

  • The spreadsheet is simple. You just input the data in dark yellow highlight
  • Pump sizing is calculated based on rated flow rate. If you want to size based on normal flow rate, input 0 in percentage of rated flow rate
  • Pressure drop components is comprehensive, including pipe loss, fitting loss, and equipment loss
  • Pump data results is comprehensive, including:
    • Suction pressure
    • Discharge pressure
    • Differential pressure
    • Differential head
    • Hydraulic power
    • Pump BHP
    • Rated power (calculated)
    • Rated power (selected) : based on commercial output motor power
    • NPSHA
    • NPSHR
    • Shut in pressure

Stop reading! Start downloading! Hope you find this useful!

[button style=”btn-default btn-sm” icon=”glyphicon glyphicon-save” align=”left” iconcolor=”#4285bf” type=”link” target=”false” title=”Download Pump Sizing” link=”https://missrifka.com/?attachment_id=1791″]

Spreadsheet of Air Compressor and Air Dryer Calculation

Rifka Aisyah 2 Comments

In previous post, I shared about how to calculate capacity of air compressor and air dryer. In this post, I want to share you spreadsheet of the calculation. I made the spreadsheet simple so it can be used easily. You just need to input:

  • Quantity of shutdown valve (SDV)
  • Quantity of control valve (CV)
  • Number of utility station/utility connection
  • Capacity of nitrogen generator

In this spreadsheet, I assume to use dessicant type air dryer, so that you also need to input air loss during regeneration.

This is the screen shoot of example.

Air compressor and air dryer calculation spreadsheet
Air compressor and air dryer calculation spreadsheet

At the beginning, I planned to create online calculator. But I thought it will be difficult for me to prepare it and it also takes time if I prepare it by myself. I hope this spreadsheet is useful!

Compressor calculator

 

Fail-safe position

Fail-Safe Position Selection of Control Valve

Rifka Aisyah 1 Comment

In designing a processing facility, we usually use control valve to manipulates the temperature, pressure, level, or fluid flow rate in process system. The selection of control valve, which is air-to-open or air-to-close, is base on safety consideration. In case of power loss or air failure , control valve should move in safe position (fail-safe).

Fail Position

Fail position is the term used to describe how control valve will react when there is loss of power. I read there are three different fail positions. Read More

Pressure Level in Pressure Vessel Requirement

Rifka Aisyah Leave a comment

I am very interested in learning API 520 and API 521 (everything about pressure relieving system). It is because that is the weakest point of me. I want to try make my understanding better, starting from pressure level.

I have heard and read so much about pressure terminology since years ago but still confusing until now. What was the MAWP, MOP, design pressure, set pressure, relieving pressure?

In this post I want to share what I read in API RP 521 (Guide for Pressure Relieving and Depressuring Systems). I read about some terminology in pressure level so that I hope I will not confuse about terms anymore.

Let’s see some terms in column Pressure Vessel Requirement. Read More

Regulating Sector

Regulating Sector at City Gas Distribution System – Understanding

Rifka Aisyah Leave a comment

This is the forth post of city gas series. Check my previous post about how to calculate city gas flow rate, city gas network part 1, and understanding metering and regulating station. In this post, I want to share you about regulating sector. 

Before being distributed to house, gas pressure and gas flow from tapping point will be monitored in metering and regulation station (MRS). After leaving MRS, gas will be distributed via distribution pipeline which is usually MDPE pipe.

In my project we use 63 mm pipe or 90 mm pipe for distribution pipeline.

Gas distribution is usually grouped. Each group covers several houses, which can be as low as 900 houses to 2000 houses. In each group, we installed regulating sector.  Read More

Example metering and regulation station

Understanding Metering and Regulating Stations and Its Part

Rifka Aisyah Leave a comment

This is the third post of city gas series. Please check the first post about how to calculate city gas requirement and the second post about city gas distribution network part 1. 

In previous post, I share you one important part of city gas distribution equipment which is Metering and Regulating Stations (MRS). For review, the function of MRS is to monitor flow rate of gas and to reduce gas pressure thus it meets requirement. Gas pressure is reduced from more than 16 bar to 5-15 bar in MRS. I checked in “City Gas Network Handbook” published by Indonesian Government, maximum pressure of city gas distribution system is 7 bar, although in reality, gas operating pressure is not that high. Read More