What is a P&ID?

Excel Tutorial - 1 : Mass balance calculation using Microsoft Excel

We know that out there in this free information world, lot of soft-wares are available which ease the complexity of work. What if we can design our own mini super ninja software ( actually Excel files) to reduce our repetitive actions while calculating . Lets get started how to do simple calculations in excel.

In this tutorial neutralization of Sulphuric acid ( H2SO4 )   by Sodium hydroxide ( NaOH )was considered. Go through the problem statement given in the below image.

At first mention the Chemical reaction in one of the cells (A1 or B5 etc.,). Mention the molecular weights separately in a cell. This is important to put the value in a single cell ( L6 for H2O, L7 for NaOH, L8 for H2SO4, L9 for Na2SO4) it should not contain any alphabets. If you enter alphabets in the molecular weights column it will result in error.
Now we have given the H2SO4 quantity that should be neutralized. Put this value in a separate cell (D11) and convert it in to moles by dividing the mass with molecular weight mentioned in L8 cell.

Now use this moles and multiply this moles with 2 , as 1 mole of H2SO4 requires 2 moles of NaOH for Neutralization which would result in formation of 1 mole of Na2SO4 and 2 moles of H2O.

Multiply the moles by molecular weight in cell E17 to get the mass of NaOH required for neutralization.

Similarly do it for H2O & Na2SO4

Mass used for reaction should be equal to mass produced in the reaction.

Please feel free to put up your doubts and queries below.

To download the Excel file click the link

Mass Balance

Type of valves using in industries

What is a Valve?

Valve is a device which is used to regulate the flow in a pipe line. It may be mechanical thing but the function is very much required for Chemical engineering operations. Based on the requirement, allowed pressure drop, flow rate we can employ different kind of valves. Valves often change the flow pattern in pipe lines. This may be due to the obstruction or restriction offered by the valve body. Here boundary layer separation may occur, which leads to form friction. In order to calculate form friction pertaining to that particular valve we have L/D ratios and K values.

Types of valves

Here are the some of most common valves using in Chemical industries.

Globe Valves

• Globe valves offer better control of flow but at the expense of large pressure drop. Most of the control valves are globe valves.

Gate valves

• In Gate valves a Gate facilitate the flow of fluid. It will slide from complete open to close position.In gate valves the sliding stem can be movable or fixed stationary.

Ball Valves

• Ball valves contain a ball as a flow regulating element. The ball contains a provision to allow the flow. One quarter (1/4) turn of the valve handle can regulate the flow from minimum to maximum.

Plug valves

• Function of plug valve is similar to Ball valve but the regulating element will be different.

Check valves( Non Returning Valves)

• Check valves or non returning valves allow flow only in one direction. Opposite direction flow doesn't happen here. This is particularly useful in reactor inlets, where exothermic reactions might happen in pipe lines.

Butterfly valves

• Butterfly valves contain a disk which can rotate from 0 to 90 degrees for complete close to open state. This valve can be used as a control valve in water service.

Diaphragm valves

• Similar to Globe valve , a diaphragm valve contains a plate like arrangement which functions as a stem in Globe valve.

Control valves

• Control valves are a special class of valves which are highly useful in controlling the flow of a fluid in pipe lines from a control room. Control valve contains a stem which can be varied by giving the set points from the distributed control system(DCS). Control valve design also important thing in process industries.

Still a lot of valves are out there , each of which has its own feature. To name a few  Solenoid valves, needle valves etc.,

Useful Link : http://www.valvedirectory.com/valve_list_a-z.html

GATE 2015 Chemical Engineering

Gear up for the next biggest challenge in your career, GATE-2015 online application starts from September 1st 2015. GATE (Graduate Aptitude Test in Engineering) is a common way to enter into masters, doctorial programs and public sector undertaking (PSU) companies. This time IIT Kanpur is organizing GATE-2015. http://gate.iitk.ac.in/GATE2015

GATE-2015 Chemical Engineering (CH)

It is better to start the preparation 3 to 4 months before the commencement of exam. Practice is the mantra. The more you practice the more you will be benefited. It will be useful to solve the numerical questions. The easiest way to gain more marks is to concentrate on Aptitude, English, and Mathematics. From technical side Process calculations, Chemical technology subjects are easy to gain more marks. Fluid mechanics, Process economics, thermodynamics are easier to solve next. Chemical kinetics, Heat and mass transfer subjects come in next place. The order should be decided by you ultimately based on your preparation. Follow www.Chemineering.blogspot.com to get updates on GATE-2015 and other Chemical engineering related stuff.

#Chemieering recommends the following books for GATE-2015 preparation in Chemical engineering stream.

GATE-2015 Highlights

• GATE-2015 application fees is Rs 1500/- for male candidates in General/OBC category and Rs 750/- for female candidates. For SC, ST, PwD candidates the fees is Rs 750/-.
• Payments have to be made through debit/ATM cards, credit cards or internet banking and e-challan only
•  All Supporting documents should be sent online only. No hard copy will be accepted
• Examinations for all the 22 papers will be conducted by an ONLINE Computer Based Test (CBT). The online examination paper will contain some questions for which numerical answers must be keyed in by the candidate using the virtual keypad. Rest of the questions shall be of Multiple Choice Question (MCQ) type.
• GATE 2015 examinations will be held during forenoon and afternoon sessions on alternate weekends (Saturday and Sunday) between 31st January 2015 and 14th February 2015. Examination for some of the papers in GATE 2015 will be held in multiple sessions. Exact details regarding complete examination schedule will be notified at a later date.
• The payment of application fees would be online through different modes like net banking, debit/credit card, e-challan, etc.
• GATE 2015 score is valid for THREE YEARS from the date of announcement of the results.
• During the online GATE 2015 examination, all candidates will be provided with an online scientific calculator which has to be used to answer the questions.

Types of Chemical engineering drawings - BFD, PFD, P&ID

The terms flow sheet and flow diagrams are often used in engineering and design applications. But this is not the accurate way to describe the process drawings. This post will give a glimpse about the types of process drawings.

Basically there are three types of process diagrams in chemical engineering context.

1. BFD - Block Flow Diagrams.
2. PFD - Process Flow Diagrams.
3. P&ID - Piping and Instrumentation Diagrams.

In a brief BFD represents entire process in a single sheet, where as in PFD you can find some detailed information like plant operating conditions, process flow. It uses symbols to represent the equipment. P&IDs provide detail information when compared to above two drawings. They use standard nomenclature, symbols, and tag numbers to fully describe the process.

These drawings are very useful as they convey the right amount of process information as needed during various stages of bidding, engineering design, procurement, construction, operating & decommissioning phases of the process.

BFD-Block Flow Diagram

A BFD has the ability to represent the complete process on a little more than a single sheet. It contains mainly text enclosed by boxes, interconnecting lines with flow arrows. In some BFDs mass flow rates may be mentioned so as to describe the material balance over the entire plant.

PFD-Process Flow Diagram

PFDs contain more information than the block flow diagrams from which they are derived. They show more detail about major equipment, subsystems and the flow of product between them. A typical PFD contains equipment symbols connected by process lines where temperature and pressure information are shown on the line itself. You can easily refer the properties of a particular stream through stream number. For designing a P&ID, equipment layout PFD is mandatory.

P&ID-Piping and Instrumentation Diagram

P&IDs carry a lot of information to define the process. Derived from PFD it is the best way of accurately documenting the operation of a process. P&ID takes the conceptual aspects of PFD and expand them by adding 

1. Detailed symbols.
2. Detailed equipment information.
3. Equipment order and process sequence.
4. Process and utility piping.
5. Process flow direction.
6. Major and minor bypass lines.
7. Line numbers, Pipe spec, Pipe size.
8. Isolation and shut off valves.
9. Instrumentation controls.
10. Types of process component connections.

A P&ID can be best understood with the help of a legend sheet given by the P&ID developer. Legend sheet contains information regarding the nomenclature, tag philosophy, symbols, a lot more. Download the PDF files to know more about drawings and legend sheet.

For detail information on BFD, PFD and P&IDs download the following PDF files.

Download PDF file for Piping and symbols

 

 

Download PDF file for BFD, PFD, P&ID