Descaling Firetube Steam Boiler

Thanks slack. In my case chemical treatment of feed water is not possible as the steam is applied directly on to food product.

Is this boiler made of something other than carbon steels, then? What is it?

Is this a "boiler", or is it a "clean steam generator"? Which?

Is this steam produced to sterilise the food in some way?

Please describe the equipment and its current operation and maintenance regime.

I don't know where you are located, but there are FDA (US Food & Drug Administration) accepted boiler chemicals for culinary steam. The quantities allowed are often limited.

Are you using distilled water?

The tools required for descaling are pretty simple.

This might save a little time. Wear eye protection and take care not to damage the tubes.

If the original poster is using the "boiler" to produce steam that is going directly into foodstuffs (and so far a full explanation has not been revealed to the forum), then it would probably be best to use a stainless steel wire brush instead of a bog-standard one, perhaps.

You might be surprised if you get a magnet too close to your breakfast cereal .

Maybe so. Either way, everything has to be thoroughly cleaned afterwards.

I used to have to descale fresh water evaporator plates, back in the Navy; it's nasty, hard work. I suspect he will probably find a source of mineral free water, once the tubes are cleaned.

...which is why a discussion with a reputable boiler water treatment chemicals company is overdue. There shouldn't be any scaling inside the "boiler", as it will introduce sulphates and carbonates of calcium and magnesium into the water (magnesium sulphate is a laxative) and also silica (would one eat sand and grit <rhetorical question - NNTR>?) into the foodstuff.

The question over the materials of construction of the "boiler" remains unanswered. One wouldn't want steel corrosion products in the foodstuff either!

Until further information is forthcoming, all one can say is that the "boiler" is currently unsuitable for the job. There are solutions, which would benefit from more information becoming available.

Is there a qualified Process Engineer at this facility? If not, can a consultant be hired?

Please advise.

Slack, This is a normal steam boiler. As you said there is deposits of sulphates /silica/calcium inside which are visible while blowdown. The steam is used to give glossy surface on food product. Feed water additives are not used to prevent contamination of product. Now I want to shut down the boiler and make a chemical descaling

This happens often for steam direct in contact with foodstuff.

Direct (Culinary) Steam Inject, that's how Cheese is cooked.

You have to talk to your boiler and and chemical Representatives.

In my experience, to do the job. You may have to call in a professional cleaning service.

We purchased a used condenser, where a number of the tubes were plugged. they came in with a high pressure washer.

The introduction of boiler treatment chemicals would help but could be expensive for your operation. If the boiler is to cleaned, rinsed thoroughly and then put back into operations you can use a chemical that is cheap and readily available, Sodium Hydroxide. Most of the boiler treatment chemicals consist of a sodium hydroxide (lye, caustic soda, lager) solution and a few chelating chemicals. The charlatans make the silt bind together into easily removable larger particle.

When the boiler is no longer going to be used and prior to shutting down, add about a quart of 50% sodium hydroxide solution into the wet side water. This will help remove the sludge and dirt accumulated on the metal. Operate the boiler for as long as time permits. Next, drain the boiler and add clean water and circulate it through the boiler. Circulate a while, as long as available and again dump. The sodium hydroxide will clean the metal without damaging it and keep the silt in suspension.

Sodium hydroxide is available in supermarkets as lye or drano. Check the label for composition and concentration. If you mix your own from Sodium Hydroxide pellets use extreme caution in handling it. Always use proper PPE. It cleans metal but burns skin severely.

Good Luck, Old Salt

Thank you all for valuable contributions

what O.S. say.

just reading "how to descale water chamber of a fire tube boiler having water holding capacity 3000 Liter? " - seems looked like 'chamber' already needs some work first and then perhaps on-about preventive maintenance in food use; and also about water filters that are readily available.

G: seemed readable, your sufficient description -=enough <smile>

chem co/s (get a couple non-presumptuous objective opinions) some may even find for you that other common 2% to 3% solutions (name withheld) may not pit a clean spot, while other area surfaces are cleaned

food divisions of Dow and the like will have other notes

Don't use acid, cheap but does damage to your boiler, we use chemicals from Delta Products Group in Aurora, IL. Can be held in your hands and flushed down any drain following use, cleans our boilers like nothing I've seen before and safe as the day is long!

DirkCampbell-

Sodium Hydroxide is not an acid. It is the opposite of acid, a base. Sodium hydroxide is normally stored in steel storage tanks or plastic storage tanks and drums. Many boiler cleaning chemicals are a base liquid of Sodium Hydroxide (Caustic Soda) dissolved in water, stabilizers, surfactants, and buffers. Sometimes a small quantity of soap is added. This is the most frequent basic formulation for boiler treatment chemicals. Caustic does not damage the steel in boilers. Most soap, including hand soaps is caustic (pH greater than 7.0). They remove the sludge and silt from the steel tubes and other metal parts, suspend it in the water and allow the dirt to be removed during the blow-down.

Ivory Soap, one of the first commercially available hand soaps was made by heating Caustic Soda with animal fats. It produced Sodium Stearate, the ester of Stearic Acid and Caustic Soda. The Sodium facilitates the removal of the dirt from the metal and the stearate makes it suspended in the dirty water. Those of us who are longevity fortunate may remember our mother boiling Lye (Sodium Hydroxide) with animal fats to make soap.

Sodium Hydroxide is used to remove crud from steel without eating away the steel. Acids are used to remove the surface layer of the steel.

Good Luck, Old Salt

Hi there.. you gave me good idea about descaling through caustic soda... can you please give me an idea about the ratio or quantity of caustic soda to be used if my boiler capasity is 50liters...thank you

GOOGLE the question. Examples for this could be "formulas for using liquid caustic soda for cleaning boiler tubes"; "cleaning boilers with liquid caustic"; etc.

There are many types of boilers made out of a great variety of metals. To take one persons advice (who knows how good it is?) is foolish, unhealthy and can perhaps destroy the boiler. Get as much information as you can.

What about contacting the boiler fabricator? They should be a good source of information.

Good Luck, Old Salt