Absorber

absorber

[əb′sȯr·bər]

(chemical engineering)

Equipment in which a gas is absorbed by contact with a liquid.

(electronics)

A material or device that takes up and dissipates radiated energy; may be used to shield an object from the energy, prevent reflection of the energy, determine the nature of the radiation, or selectively transmit one or more components of the radiation.

(engineering)

The surface on a solar collector that absorbs the solar radiation.

(mechanical engineering)

A device which holds liquid for the absorption of refrigerant vapor or other vapors.

That part of the low-pressure side of an absorption system used for absorbing refrigerant vapor.

(nucleonics)

A material that absorbs neutrons or other ionizing radiation.

Absorber

A component of a solar heater that soaks up heat from the sun and helps transmit it to the water or heating system.

Absorber

 

basic processing equipment in absorption processes. The absorber, frequently called a scrubber, features a developed surface for phase contact between a gas and a liquid. Several types of absorbing towers are known.

The absorbing tower (Figure 1) is a metal or ceramic column accommodating several horizontal grids (1) with beds of packing (2) (coke, metallic or ceramic rings, wooden gratings, stones, and so forth) and is designed to increase the gas-liquid phase-contact surface area. A mixture of gases enters the bottom of the column through the pipe (3), and the absorbent material fed into the tube (4) flows downward through the packing counterflow to the rising mixture of gases. As a result of this counterflow contact of the gas and vapor phases, the components of the gas mixture to be absorbed in the absorbent bed go into solution completely. The nonabsorbed gas

Figure 1. Absorber

Figure 2. Plate absorber

mixture components are vented from the tower via pipe (5), while the saturated absorbent flows downward through pipe (6). The cones (7) intervening between the packing sections (2) direct absorbent pushed out by the vapor toward the wall of the absorbing column back toward the center, in order to achieve more uniform wetting.

A more complicated absorbing tower comprises a column (Figure 2) in which trays (1) equipped with pipe connections (2), caps (3) with serrated edges, and overflow tubes (4) replace the grids and packing. The absorbent flows down from the tray to the tray below through the overflow tubes, while the mixture of vapors moves upward, bubbling through the layer of liquid. The vapor stream, on passing through the serrated edges of the bubble caps, breaks up into a mist of fine bubbles, thereby presenting a larger vapor-liquid phase-contact surface area. In some cases, trays in which a large number of holes have been drilled—sieve trays—are used instead of bubble-cap trays.

Absorbent towers in which the vapor moves over the surface of the liquid (bonbonne), or where the liquid becomes dispersed in fine droplets in the gas by the action of nozzles rotated by disks or turbines, are frequently employed in processes where the vapor dissolves in the absorbent.

REFERENCES

Ramm, V. M. Absorbtsiia gazov. Moscow, 1966.
Ciborowski, J. Osnovy protsessov khimicheskoi tekhnologii. Leningrad, 1967. (Translated from Polish.)
Kasatkin, A. G. Osnovnye protsessy i apparaty khimicheskoi tekhnologii, 8th ed. Moscow, 1971.

V. L. PEBALK

absorber

1. A device containing liquid for absorbing refrigerant vapor or other vapors.

2. In an absorption system, that part of the low-pressure side of the system which is used for absorbing refrigerant vapor.

3. That part of a solar collector whose primary function is to absorb radiant solar energy.