172-65603MA-06 (SR-B1.5/SR-B4) 14 Feb 2020
System Principle
Because the hot water recovery side of the SR-B1.5/SR-B4 high-temperature waste
water heat exchanger is open to the atmosphere, there is hardly any back-pressure
(maximum 50 mmAq (0.07 psi)) on the boiler or the equipment where the high-temp.
water is generated. For this reason, it can be used without the restrictions of pressure
vessel regulations in most locations. Consult TLV for details.
Concerning the construction of the unit, there is a hot water outlet in the base of the
heat exchanger. This allows a water seal to be maintained which prevents flash
steam leakage. Thus, with a similar construction to closed type heat exchangers, it
can ensure an equivalent level of high efficiency heat exchange.
<Operation flow of high-temperature waste water heat exchanger SR-B1.5/
SR-B4 (hereafter, SR-B)>
①High-temp. water flows into the SR-B
from equipment connected to the
blowdown/high-temp. water inlet.
②High-temp. water and re-evaporated
steam from high-temp. water which has
flowed into the SR-B (shell side)
transfers heat to cold water inside the
heat transfer coil.
③Upon transferring heat the flash steam
that has recondensed and high-temp.
water which has had its sensible heat
consumed drops down to collect in the
base of the SR-B.
Furthermore, since flash steam inside
an airtight space produces a fall in
pressure, the inside of the SR-B is
maintained at atmospheric pressure or
a very slight vacuum (-0.5 kPaG (-7
psi)) which ensures a smooth influx of
high-temp. water.
④High-temperature water accumulated in
the lower part of the tank seals the shell,
and it becomes similar in structure to a
pseudo closed type heat exchanger.
⑤Once high-temp. water flows in and
accumulates up to the water levelfor the
blowdown/high-temp. water outlet shown in
the figure to the right, it will be discharged through the blowdown/high-temp. water outlet.
⑥If the amount of high-temp. water increases such that it cannot be fully
discharged though the blowdown/high-temp. water outlet, and thus accumulates
up to the overflow water level shown in the figure above, it will be discharged from
the overflow outlet.
⑦If the cold water flow rate decreases, or else the ability of the cold water to
absorb heat is surpassed causing a generation of flash steam; even if flash
steam accumulates inside the SR-B and the pressure begins to rise; the instant
that the pressure rises above 0.5 kPaG (7 psi) (a water seal with 50 mm (2 in) of
head pressure) the water seal will be broken and flash steam will be discharged
to the atmosphere through the exhaust outlet. (pressure will not accumulate
inside the unit)
Exhaust
Outlet
Boiler Feed Water/
Hot Water Outlet
Boiler Feed Water/
Cold Water Inlet
Blowdown/
High-temp.
Water Inlet
6
1
2
3
5
4
Blowdown/
High-temp.
Water Outlet
Overflow Water Level
Water Level for
Blowdown/High-temp.
Water Outlet
6
Body
Blowdown
Outlet
Overflow
Outlet
