Hot Tip #5 - Water Hardness
Has your plant ever run on hard water, even for only a day? How damaging could 1 day be? If a laundry is using 200 gallons of water per minute with a water hardness of 20 grains: The total mass of hardness that should be removed if the facility were to run for 16 hours is?
A) 0.25 pounds B) 2.5 pounds C) 25 pounds D) 250 pounds E) More than A, B, C & D combined.
Calculation:
(200 GPM * 60 Minutes/hour * 16 hours * 20 Grains) / 7,000 Grains per pound = 548.6 pounds
This 548 pounds hardness (Calcium & Magnesium) would have a volume of approximately 50 gallons! If your boiler is using 5% of your total water, then approximately 2.5gallons of contamination could occur in 1 day of running hard. This is enough contaminate to cover the tubes in a 400-horsepower boiler with 0.002 inches of insulator! Imagine using 2.5 gallons of paint per day to coat your boiler tubes!
Calculation:
(2.5 Gallons * 231 Cu. In. /Gallon) / (400 BHP * 5 Sq. Ft. /BHP * 144 Sq. In. / Sq. Ft.) = 0.002 Inches
Hot Tip #4 - Combustion Air
As the cold weather arrives, we frequently start closing doors in and around our boiler room.
This blocks off the needed combustion air to the boiler. The required make-up air opening is:
5 square feet per 1,000,000 BTU's per hour.
A 300 BHP boiler would require: 300 * 33,000 /1,000,000 * 5 = 49.5 square feet
THIS IS 49.5 SQUARE FEET OF UNRESTRICTED AIRFLOW
If the air make-up opening is restricted (which it always is), with louvers or screens, then a larger opening is required.
Typical devaluation factors caused by these restrictive devices are 40 to 70 percent.
So, the required opening of 49.5 square feet can approach: 49.5 / (100% -70%) = 165 square feet.
Since the cold weather places a larger load on boilers, it becomes more vital that we monitor boiler efficiency closely.
Hot Tip #3 - G Force
Some newer washer-extractors can be programmed in G force.
G force is equal to: RPM2 * Diameter (inches) / 70,500
Example: If a washer basket is 65 inches in diameter & spinning at 570 RPM then the resulting
G force is: (570 RPM * 570 RPM * 65 INCHES / 70,500) = 299.6 G’s
Fun facts on G force comparisons:
Moon surface at equator = 0.1654 G’s, Earth surface at sea level = 1.0 G,
Space Shuttle at launch = 3.0 G’s, Apollo 16 on reentry = 7.19 G’s
Generally, we will extract everything going to a dryer at maximum G force. Uniforms and napery may be extracted at lower G forces. We don’t want these classifications too dry before finishing.
“General Rule of thumb”: The wetted the goods going to pressing / finishing the better the finished quality. This of course assumes that the goods exit the finishing department dry.
Hot Tip #2 - Air Compressors
Compressed air leaks are costly. Do you know how much of your compressed air is wasted?
Air compressors are frequently the largest motor drive machine within a laundry. They are among the first machines to be turned on and the last to be turned off each day. A fifty-horsepower compressor will cost approximately $5.00 per hour to run!
To measure the amount of leakage in your system, the following procedure can be used.
- When the laundry is shut down and not using air, turn on the compressor.
- Once the system is pressurized and the “unloading valve” closes, start a stopwatch.
- When the “unloading valve” opens, record the unloaded time. This is the unloaded time
- Continue measuring the time until the “unloading valve” closes again. This is a complete cycle, which is the sum of the unload time & the load time.
- Leakage is equal to compressor horsepower multiplied by (load time / total time).
- Example: 50 HP X (90 seconds / 170 seconds) = 26.5 HP or 53% or total compressor output!
Don’t be surprised if a third or more of your air is wasted. Even new facilities, with all new equipment, frequently have 20% or more!
Hot Tip #1 - Feed Temperature
Monitor your boiler feed water temperature. Is it too hot? Too cold?
Temperatures below 180° F. can cause excessive oxygen to enter your boiler and cause premature tube failure. Oxygen is about 6% soluble at 150 F, and about 2% at 210 F.
Why is your return temperature this low? Is all available condensate getting returned?
Or, more likely, is the feed tank too hot, (above 250F.) venting excessive return steam energy? If so, it’s time to perform steam trap maintenance!
If your facility occasionally operates with only 100% condensate return machines on line; such as ironers, garment presses, steam-heated coils, etc. It is very likely that your return system can exceed 250 F. Time to install a vent condenser!
Vent condenser should be mounted above your boiler feed water tank. (Tank vent piping should enter & exit this condenser. Condensed steam then falls back into feed water tank. Do NOT confuse this with a condensate cooler!