Calderas de circulacion forzada

Variacion de la relacion peso especif agua/vapor con la presion

Principio de circulación forzada monotubular

Caldera Benson

* Primera caldera

de circulacion

positiva forzada

* Diseñada para

operar a presion

crítica (217

kg/cm2) y temp de

374 °C

Caldera, Sulzer

Principio de recirculación forzada

Caldera Leofler

(1923, sin mucha aceptacion)

Caldera La Mont

Caldera Eckrohr Kessel

Comparación

• The riser tubes S are heated.

• The density difference between downcomers F (pure water) and riser tubes S (mixture of water and steam) causes a flow upside to the drum.

• In the drum, water and steam are separated. The water flows through the downcomers F to the headers of the riser tubes.

• Also in Eckrohr boilers riser tubes S are heated.

• The water-steam mixture flows upwards.

• In the upper header Z steam is partly separated from water. The water flows through unheated return tubes R to the lower headers V.

• The partly separated steam flows through the overflow tube U to the steam space of the drum. The remaining mixture runs through mixture tube G.

• The final separation of water and steam takes place in the drum. The lower headers are fed by the downcomers F.

• Due to the return tubes R the route of water is shortened and the water circulation is improved.

• The heating surfaces can be arranged at quite a long distance from the drum.

Caldera Eckrohr Kessel

Calderas de Fluido térmico vs calderas de vapor de agua

Caldera de fluido térmico

• Liquidos de media

temperatura: productos

petroliferos, productos

organicos sintéticos (diphenil)

, mercurio

• Liquidos de alta

temperatura: sales minerlaes

fundidas (nitrito de sodio,

nitrato de sodio), metales

funidos ( sodio, potasio)

• Liquidos de altisima

temperatura: bismuto

fundido, litio, zink, etc.

a) Paredes integralmente cubiertas de tubos (evitan uso de

componentes refractarios, para evitar permanencia de carga termica).

b) Uso de ante hogar para combustible solido