The primary function of a blow down separator is to allow the boiler operator to safely and legally handle the bottom blow down water that comes from the boiler. There are two types of boiler blow down. The bottom blow down is done by opening a set of two valves that drains water out of the bottom of the boiler. The purpose of the bottom blow down activity is to clean out solids that accumulate in the bottom of the boiler. Keeping the inside of the boiler clean improves the efficiency of the boiler.
The blow down separator, with the use of the attached after cooler, is designed to reduce the temperature of the water to at least 140 deg. F. before it is dumped into the sewer.
So, how does the blow down separator manage that temperature reduction? The first step is the creation of flash steam in the centrifugal separator. When the high pressure hot water comes into the blow down separator pressure vessel it hits a striking plate and droplets form. A portion of the water changes to flash steam due to the pressure drop. A portion of the water, depending on the initial boiler pressure, can be converted to flash steam which is vented to the atmosphere. The water that remains after the steam is created will be at 212 deg. F, and it still needs to be cooled to a minimum of 140 deg. F. by the after cooler before it can be dumped into the drain. The main issues with creating the flash steam are having enough volume in the pressure vessel to handle the steam without building up pressure, and making sure the vent piping is large enough to handle the high flow rate of flash steam.
The second phase of the cooling process is accomplished in the after cooler. When the hot 212 deg. F. water exits the blow down separator pressure vessel it enters the after cooler. The after cooler tempers the hot water with the addition of cooling water just like a home faucet does. An automatic temperature regulating valve opens as soon as the temperature bulb is impacted by the hot water. Cooling water is mixed with the hot water at a rate to get the temperature of the combined flow to at least 140 deg. F. as it goes to the drain.
Lattner Blowdown Separator Tanks Durable ASME CODE steam boiler blowdown separators safely reduce steam pressure for external venting ... reduction to a maximum of 5 psi. Water is drained through the bottom threaded coupling; steam is safely vented out the top to the atmosphere. All joints and seams are welded and hydrostatically tested. Constructed of heavy duty 1/4" or 3/8" (1600 & 1800) thick steel. Seven models up to 150 psi are available. National Board Stamped ASME CODE up to 150 psi 650°F Plus a reasonable one year warranty, backed by over 80 years of responsible customer service National Board Stamped ASME CODE up to 150 psi 650°F High pressures available on request 1" NPT Couplings provided for optional support legs which are adjustable - order separately. Model 1450 Separator w/ Optional Automatic Aftercooler and Optional Support Legs.
|Part #||ASME Pressure||A Inlet||B Vent||D Drain||E Dia.||F Oa. Ht.||G||H||Ship Wt.|
|810||150 PSI||1"||2"||2"||8-5/8"||17-3/8"||8-3/16"||1-1/4"||47||Add to RFQ|
|1450||150 PSI||1-1/2"||3"||3"||14"||29-11/16"||18-3/8"||1-5/8"||155||Add to RFQ|
|1600||150 PSI||2"||6" Flg||5" Flg||16"||44-3/4"||30-5/8"||1-7/8"||310||Add to RFQ|
|1800||150 PSI||2-1/2"||6" Flg||6" Flg||18"||46"||31-1/4"||2-1/8"||350||Add to RFQ|
Assembly includes ball valve, check valve, strainer and automatic temperature regulating valve. The aftercooler reduces boiler blow-off to a safe temperature. Local codes vary and should be checked upon installation.
Selection is based upon the separator’s drain connection as noted on the selection chart below. Each assembly is factory piped and includes a ball valve, check valve, and discharge thermometer.
Boiler blow down is mandatory. A boiler cannot continue operating for very long wihtout expelling the left behind solids as steam is generated. Periodic blow down must take place. This can be accomplished with the addition of an automatic blowdown assembly. A boiler that is blown down regularly will maintain high efficiency and last longer. (The use of an automatic device should not preclude periodic visual examination of the boiler blow down effluent to examine that the automatic assembly is working as intended.) Selection is based upon the boiler's drain connection as noted on the selection chart below.
Each assembly is factory piped and wired, and includes a ball shutoff valve, ball by-pass valve, motor driven ball valve, and NEMA 1 panel containing the interval timer. Lattner Blowdown System with Separator and Automatic Aftercooler.