MONOBLOCK PUMP TYPES AND APPLICATIONS

          A Monoblock Pump is a mechanical device. We all know that 'Mono' means single. The prime mover of the pump (i.e., Motor) and pump are built together in same housing, that type of pumps is called as "Monoblock Pumps".

          In which a common shaft contains all the rotating parts. Because of this, during the transmission from motor to shaft, loss of energy is minimal. Motor assembly and pump assembly is the main components of monoblock pumps. The device's impellor and volute chamber are designed in a manner that it offers best hydraulic efficiency and characteristic related to suction lift. Most advanced machinery, dynamic balanced impellor, seals and ball bearings are used for the manufacturing process. Due to the dynamically balanced rotor, there is less noise and vibration. The shaft is made up of high-quality steel.

Types of Monoblock Pumps:

          Different types of monoblock pumps are available in the market, mainly include

              1) Centrifugal Monoblock pumps

              2) Submersible pumps

              3) Booster pumps 

Features/Advantages: –

a) It's unique design that helps in the prevention of overloading and the burning of the motor even during prolonged use.

b) They are simple and compact. They need less space for installation.

c) They are cost effective.

d) Weared parts can be easily replaceable.

e) These pumps bears fatter efficiency curve which helps in efficient functioning.

f) With dynamically balanced rotating parts, there is less noise and vibration while working.

g) The pump has less complexity in installation and maintenance is also easy.

h) They are self supporting, these pumps do not need additional base plates and coupling for installation.

i) Automatic release of air while priming.

j) These pumps has a sturdy design as they can endure three phase voltage fluctuations.  

PROBLEMS ON AVERAGE - 1

Examples 1: what will be the average of 11, 12, 13, 14, 15, 16, 17 series?

Solution: The common difference is same i.e., 1, so the series is in A.P. Average is the middle term when the number of terms is odd, So the middle term is 14 which is our average of the series.

Example 2: What will be the average of 11, 12, 13, 14, 15, 16, 17, 18?

Solution: Since the common difference is same for each of the term we can say that the series is in A.P. So we have discussed that when the number of terms are even then the average will be the average of two middle terms.

Now the two middle terms are 14 and 15, and the average is (14+15)/2 = 14.5

Example 3: The average of five numbers is 29. If one number is excluded the average becomes 27. What is the excluded number ?

Solution: let the excluded number is

= (29 x 5) – ( 27 x 4 )

= 145 – 108

= 37 .

Example 4: Find the average of first 20 natural numbers?

Solution: 

Sum of first n natural numbers = n ( n + 1 ) /2

So, we can find easily average of first 20 natural numbers 20 x 21 / 2 = 210 

So, then Required average is = 210 / 20 = 10.5.

Example 5 : Find the average of first 20 multiplies of 5 .

Solution: 

Required average = 5 ( 1 + 2 + 3 +……………….. + 20) /20

= ( 5 x 20 x 21 / 20 x 2) = 2100 / 40 = 52.5 .

So the Required average is 52.5.

Average || Important Formulas and Shortcuts of Average

          Dear readers, we all know that speed and accuracy in calculation is much needed for Quantitative Aptitude section of various competitive exams and if we know enough Short Tricks in Quantitative Section, we will surely score better in the section. So, let us make it easy for all of you through these Simple and Easy tricks on Average which will not only make quantitative questions easy but  also save our time. The tricks will be helpful for the upcoming Indian RRB Exam , SSC CGL Exam and much more.

What is Average?

          Average is obtained by adding several quantities together and then dividing this total by the number of quantities given. 

The main term of average is equal distribution of a value among all which may distribute persons or things.

Here is average based some fact and formula and some average shortcut tricks examples.

Formula:

· Average = (Sum of observations / Number of observations).

Find the Average Speed

· Average Speed = (Total Distance Covered/Total Time Taken).

· If a person travels a distance at a speed of x km/hr and the same distance at a speed of y km/hr then the average speed during the whole journey is given by-   

· If a person covers A km’s at x km/hr and B km’s at y km/hr and C km’s at z km/hr, then the average speed in covering the whole distance is- 

· If value of each term increases/decreases by ‘x’, then the average of the group also increases/decreases by ‘x’.

· There are two batches A and B in a class. If we have to find the average of the whole class use the formula:
Batch A: Number of students = a
                  Average of batch A = x
Batch B: Number of Students = b
                  Average of batch B = y

Average of whole class (Batch 1 and Batch 2) = (ax + by)/(a + b)

When a person leaves the group and another person joins the group in place of that person then-

· If the average age is increased,
Age of new person = Age of separated person + (Increase in average × total number of persons)

· If the average age is decreased,
Age of new person = Age of separated person – (Decrease in average × total number of persons)

When a person joins the group 

In case of increase in average age

· Age of new member = Previous average + (Increase in average × Number of members including new member)

In case of decrease in average age

· Age of new member = Previous average – (Decrease in average × Number of members including new member)

If the numbers are in Arithmetic Progression there are two cases

· when the number of terms is odd the average will be the middle term.

· when the number of terms is even then the average will be the average of two middle terms.

PROBLEMS ON AVERAGE - 1

Suction couch roll

          Couch roll (also known as “cooch”) is used in paper machine to remove water by application of vacuum. It acts as the last “wrap” where the wet web leaves the forming wire (wire part) and enter into the wet-press section (press part). On the surface of the couch roll we found rows of small holes to suck the water. Inside the roll baffles (long and end strips) are present. These baffles direct the vacuum towards the portion of the roll where the wet web of paper is on the fabric. Below of the long baffle strips air tubes are present for strip movement. Below the end baffle strips springs are present to seal the roll for vacuum suction creation. In the vacuum box one shower will present, it cools the rubber material on the roll. In vacuum boxes if we increase the vacuum we need more power to drive the forming fabric. But in couch roll if we applied too high vacuum it produces visible suction-hole “shadows” due to the movement of fines within the sheet.

Is it necessary to Align A Flexible Coupling?

          When I started my career as a maintenance engineer i got a doubt, is it necessary to align flexible coupling too?? we are using flexible coupling instead of fixed or rigid couplings because they don't have to be aligned??.

Later I read some articles and found some useful information. Today I wanna share this information with you people.

Courtecy : T B Woods Inc

For every coupling its manufacture give some common value of alignment specification:

According to T.B Woods Sureflex Coupling (with an 8je insert) 

--> Cost : about $XXX per sleeve or insert

--> Maximum  RPM : 4500

--> Parallel Misalignment : 0.020 in

--> Angular Misalignment : 0.094 in (about 0.012"/inch)

          Based on these manufactures recommendations the coupling can bear or tolerate some sort of misalignment. and also the insert (i.e rubber) is inexpensive then why we have to go precision alignment??

          Because we are aligning shafts -- we are not aligning couplings. The coupling sleeve or Insert that we use can tolerate that misalignment but the bearings on the shafts, oil seals, gears and also shafts can't tolerate.

Sometimes coupling will bend, but also it resists bending, for this it need some good amount of energy to oppose that force. That enegy is produced within itself by:

1) Increased heat due to friction

2) Increase in load on bearings, shafts, and seals.

          So finally i got to an conclusion, "is it necessary to align a flexible coupling?"- we should not worry about it but aligning the shafts to precision alignment is necessary. because, by this we will increase the machine life,  decrease vibrations, reduce energy consumption and also the couplings life.