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FD or Forced Draft Fans supply combustion air to the boiler. Different combustion controls demand a supply of combustion air in different ways but what they have in common they control the FD fan to provide enough air for complete combustion in the boiler furnace. In most systems in use today the ID or Induced Draft fan sucks the products of combustion from the boiler furnace, through the various passes of the boiler and pushes it out the chimney. How much or how fast this fan works is based on furnace pressure. The ID fan control set point is based on combustion side furnace pressure. If the furnace pressure goes up the ID fan removes more air to lower the pressure. As the furnace pressure goes down the ID fan removes less air. This air flow out of the boiler is referred to as draft.
Both the FD and ID can be controlled by various means. The air flow can be restricted in the plenum or ducts by dampers or louvers or the speed of the fan can be changed by mechanical means from a fixed speed driver. Also the speed of the fan can be changed by the use of a variable steam turbine or an electric motor with VFD (Variable Frequency Drive)
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How do you write a logo program for a rectangle?
fd 60 rt 100 fd 60 rt 100 fd 60 rt 100 fd 60
To write a c program that counts number of blanks in a text file using standard io in unix?
#include<sys/types.h> #include<sys/stat.h> #include<unistd.h> #include<fcntl.h> #include<stdio.h> int main() { char str[100]="abc d e f gh"; int c=0; int fd,n,i; n=strlen(str); fd=create("multiple.c",O_WRONLY); write(fd,str,n); close(fd); printf("file created /n"); fd=open("multiple.c",O_RDONLY); read(fd,str,n); for(i=0;i<=n-1;i++) { if ( str[i] == ' ' ) c++; } printf("no of spaces =%d",c); }
How do you draw a triangle using logo commands using three lines?
fd 60 rt 120 fd 60 rt 120 fd 60 rt 120 will cause the turtle to draw a triangle. The square brackets indicate that the enclosed commands are to be executed three times, repeat 3 [fd 60 rt 120] Search Google with: "logo commands triangle" and have a look through the websites on the subject.
Full form of LOGO?
logic oriented graphics oriented
What is the Logo command to draw alphabet k?
Starting from the centre, move forward 100 pixels, turn 180 degrees and move forward 100 pixels (returning to the centre). Then turn 120 degrees. Repeat three times. repeat 3 [fd 100 rt 180 fd 100 lt 120]
Why vfd is used with fd fans?
Traditionally dampers are used to control the quantity of air entering the boiler. If we use VFD for FD fan, we can control the quantity of air be changing speed of fan using VFD. This will save energy.
How can you calculate the flow of FD fan and motor power when you know fan speed and impeller diameter?
times by 2
Forced draft fan vs induced draft fan?
In a balanced draft boiler, you actually have both: forced draft (FD) fans supplying air to the furnace, and induced draft (ID) fans removing flue gas. Typically, the FD fans control airflow, while ID Fans control furnace pressure to slightly below atmospheric pressure. In general though, the choice between forced draft and induced draft is based on how "tight" the system is - if you have leaks, it is better to use ID, as FD will cause product loss.
What is the difference between ID and FD fan?
no
Why cant you use a forced draft fan in place of induced draft fan?
It can be used, however not on the same piece of equipment. A forced draft fan is typically much smaller than an induced draft fan. A FD fan moves cooler air into the combustion zone while the ID fan removes the products of combustion from that zone. Typically the volume of gasses the ID Fan needs to remove is from 125% to 200% more than that of the FD fan. example: an FD fan moves 20,000 scfm of air at 100 *F, what size ID fan do you need if the exhaust gasses are 450 *F and the products of combustion and moisture add 3500 cfm to the volume of gasses? PV/T = P'V'/T' with pressure being negligible (it usually isn't) the formula is then : V/T = V'/T' to get the volume needed for the ID fan then: VT'/T = V' V = 20,000 scfm, T = 560 *R (absolute zero scale) and T' = 910 *R 20,000 scfm x 910*R/560*R = 20,000 scfm x 1.625 = 32,500 scfm thus, the ID fan must be sized at least 62.5% larger than the FD fan.
What removes the combustion gases from a balanced draft furnace?
A balanced draft has both ID and FD fans. ID Fan works by pulling the gases through the furnace hence creating the required draft. Where as FD fan pushes the gases into the furnace. Hence in a balanced draft frunace, the ID fan can said to be removing the combustion gases.
Who sings the chorus on Fd Up by BoB?
Its I Blame Coco. Its an audio clip from their song "Control"
Why continuous purging is required and point out some applications where it is required?
In thermal power plant for proper combustion we are using the air which is taken from atmosphere through forced draft fan and primary air fan .FD fan is also known as secondary air fan. Primary air and secondary air both are pre-heated before sending into boiler. In thermal power plant for preheating the air, APH (air pre heater) is used, which raises the temperature of air from 27 deg -45 deg to 220-250 deg. Primary air is used to carry the pulverized coal from pulverizer to boiler. APH at Lanco is tri sector type i.e. sectors for 1) primary air 2) secondary air 3) flue gas. Due to improper sealing of APH, mixing of gases takes place. Since the three gases are at different pressure hence mixing takes place accordingly i.e. higher pressure to Lower pressure side. Primary air is at maximum pressure so it mixes towards flue gas & secondary air. Secondary air pressure is greater than that of flue gas hence again secondary air mixes with flue gas. So we can se that chance of mixing of flue gas with Primary & secondary air is very less but the ash particles in the flue gas gets stuck to the plates of air preheater & gets mixed with primary & secondary air path, on rotation of APH. When we measure the primary air and secondary air flow through Varabar (flow element), this ash gets deposited in varabar. Due to this reason our flow measurement is not correct that is very dangerous for our power production. For proper running the boiler total air flow should always be greater than 30%. If air flow is less than 30%, boiler will be tripped & simultaneously Turbine & generator will also be tripped i.e. power production is stopped.
How do you make a star in LOGO?
to make a star on ms logo the commands should be: RT 20 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40
Command to make house in msw logo?
to house REPEAT 4 [fd 100 lt 90] fd 100 lt 90 REPEAT 3 [FD 100 RT 120] lt 90 fd 100 rt 90 fd 35 REPEAT 2 [FD 60 RT 90 FD 50 RT 90] fd -5 rt 90 REPEAT 2 [FD 40 RT 90 FD 25 RT 90] penup fd 60 pendown REPEAT 4 [FD 25 RT 90] end put that in Edall hope that helps by chloe who likes licking ou tpigs xxx
How do you make a star in ms logo?
to make a star on ms logo the commands should be: RT 20 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40 LT 70 FD 40 RT 140 FD 40
How do you draw a hexagon using logo command?
lt 45,fd 5o,rt 45,fd 50,rt 45 fd 50,rt 90,fd 50,rt 45,fd 50,rt 45,fd 50
