US2293740A

US2293740A - Fluid separator

Info

Publication number: US2293740A
Application number: US298349A
Authority: US
Inventors: Kooistra Lambert
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1939-10-07
Filing date: 1939-10-07
Publication date: 1942-08-25
Anticipated expiration: 1959-08-25

Description

g- 1942- L. KOOISTRA 2,293,740

FLUID SEPARATOR Filed Oct. 7, 1939 34 I INVENTOR.

BY #22 amerzi ff'ooisfa ATTORNEY.

Patented Aug. 25, 1942 UNITED STATE FLUID SEPARATOR Lambert Kooistra, Akron, Ohio, assignor to The Babcock & Wilcox Company, Newark, -N. J., a corporation or New Jersey Application October I, 1939, Serial No. 298,349 I 3 Glalms.

This invention relates to fluid separators of the centrifugal type. The invention provides a simp1i-- fled construction which can be advantageously manufactured.

The invention is also concerned with the e ployment of this type of apparatus in fluid systems and. it may be considered as exemplified in water tube boiler improvements whereby safe steaming capacities and water storage capacities in such boilers are increased.

A further object of this invention is to increase the range of boiler drum water levels at which centrifugal steam and water separators may be efiectively operated. The separator of the invention reliably induces a strong centrifugal action to separate vapor and liquid, and further provides for the independent discharge ofvapor and liquid in a manner to avoid re-mixlng the same, and it accomplishes this with a minimum pressure drop.

Another object of the invention is to confine the discharge of separated steam to the top of a centrifugal separator in order to prevent the separated steam from passing through separated water when the exterior water level is below the centrifugal separator. This is accomplished by providing means which afiords a liquid seal for the separated water outlet irrespective of the exterior, or drum water level, or irrespective of the rate of flow into the whirl chamber of the centrifugal separator.

Rapid circulation through the drum and the boiler circuit is desirable but as the head which causes circulation is limited, any flow restriction,

such as that involved by high pressure drop separators, will tend to reduce the flow which is a disadvantage in steam boilers or similar systems utilizing such a separator. A disadvantage of an open and unsubmerged separator is that the vapor will be discharged downward over the water level, and-it will entrain water particles which will be carried to the drum outlet. 4

The invention also relates particularly to improvements over the steam and water separators disclosed in the pending application, Serial No. 210,374, of Rowand and Fletcher, filed on May 27,

. 1938, this type of apparatus having for its object the efiective separation of steam and water with a minimum of steam and water separation space; the elimination of priming; decrease oiv water content in the steam leaving the steam and water drum; and the increase in boiler circulation rates.

The invention willbe described with reference to the particular modification illustrated in the accompanying drawing, and other objects of the Fig. 3 is avertical section through a steam and V and water separator constructed in accordance with this invention; and

Fig. 4 is a horizontal section on the line d-d of .Fig. 3.

The invention is advantageously employed to obtain a high degree of steam and water separation in such a steam generator as that shown in Fig. 1. Here, steam and water mixtures are discharged at high velocity into a separate inlet compartment of the drum 92 through the horizontal circulators, it. Some of the latter are shown as having their inlet ends communicating with uptake headers it which, in turn, receive steam and water from two banks of steam gener ating tubes l6 and it. These tubes extend across the path of combustion products from the furnace 20 and the furnace chamber 22.

Some of the steam and water mixtures dis- 36 for the bank oi tubes I6. Further downtake connections are provided by the nipples 38 which are in communication with the headers 40 for the lower bank of steam generating tubes.

Steam and water discharged into the drum l2 by the circulators l0 enters the inlet chamber 42. This chamber is formed by a side plate 44. a b ttom plate 46, and co-operating end plates. The inlet chamber extends over a portion of the length of the drum corresponding to the width of the banks of steam generating tubes and it is in communication with a plurality of steam and water separators one of which is indicated generally at 5!! in Fig. 2. Each separator includes a circular whirl chamber 52 which is fixed to the plate 44 and is in communication with the inlet chamber 42.

Steam and water mixtures enter the separator sure drop between the inlet chamber 42 and the remainder of the space within the drum l2. The flow of this mixture through the inlet 54 is substantially tangential to the Whirl chamber 52, the arrangement resulting in a whirling mass of liquid flowing around the upright wall of the whirl chamber, and the centrifugal force thus produced being efiective in separating the steam and water. I

Steam separates from the water and passes upwardly through a central opening 56 at the top of the whirl chamber, this opening being of smaller diameter than the whirl chamber, and provided by a funnel-shaped member 58 secured around its greater periphery to the top of the whirl chamber as indicated in Fig. 3 of the drawing. l

The invention involves a restricted outlet for the separated water which is discharged from the bottom of the whirl chamber and this outlet is formed by the walls of a bottom cup 60 and the lower part of the whirl chamber 52. As shown in Fig. 3, the cup 60 is telescopically r'elatedto the whirl chamber and the outlet for separated water is a circumferential space between the cup and the whirl chamber. The cup may be fixed in the position shown in any desired manner such as by a plurality of struts secured to the cup and to the exterior of the wall of the whirl chamber.

With the arrangement shown the discharge of steam is confined to the top of the whirl cham-.

and it will be appreciated that, with the illustrative construction, the outlet for the separated liquid is maintained as arestricted outlet irrespective of the drum water level and irrespective of the rate of flow into the whirl chamber. The illustrative apparatus may be effectively operated with high drum water levels above the top of the cup 60 or with low water levels at positions well below the bottom of the separator.

. The forces involved in the flow of the separated water downwardly within the whirl chamber and through the separated water outlet prevent the establishment of a water level in .the whirl chamber corresponding to the drum water level even when the latter is considerably above the top of the cup 60. The width of the annular water discharge is determined by the maximum discharge with the water level at the bottom of the chamber with an internal head available due to inlet velocity.

Spaced above the central outlet 56 of the whirl chamber 52 is a multiple plate scrubber 62. The separated steam passes between the plates of this scrubber which acts to separate drops of water therefrom and allow them to fall back into the water within the separator.

A steam and water inlet is provided by the converging

side walls

64 and, 66 and the co-opcrating upper and lower walls welded to the whirl chamber. The outer ends of these walls are fixed to a flange plate 68 through which 7 Although the invention has been described with reference to the specific embodiment shown in the drawing it is to be appreciated that it is not limited to all of the details thereof. It is rather to be considered as or a scope commensurate-with the scope of the sub-joined claims.

What is claimed is:

I 1. In a separator, a circular shell providing a whirl chamber having an outlet at its top for a lesser density fluid, inlet means so directing a fluid mixture into the whirl chamber that a whirling motion of fluid is set up therein, and a cup structure the bottom of which forms the bottom of the whirl chamber, said structure having an upwardly extending wall disposed in surrounding relationship to the lower end of the shell and spaced'therefrcm to form a substantially annnular opening constituting a whirl chamber outlet for separated fluid of higher density, said opening having a flow area less than the cross sectional area or the lower end of the shell.

2. In a fluid system, an external vapor and liquid chamber subject internally to a wide range of liquid levels, a vapor and liquid separator including a circular shell providing a whirl chamber within the first mentioned chamber, inlet means so directing a mixture of vapor and liquid into the shell that a whirling motion of the fluid is set up therein, vapor generating means externally of the vapor and liquid chamber, means aflording direct, communication between said inlet means and the vapor generating means, and cap means providing a bottom for the whirl chamber and having an upright wall radially spaced from a wall of the chamber and providing therewith arestricted and upwardly extending outlet passage through which separated liquid flows from the whirl chamber into said first mentioned chamber, said passage having a flow area less than the cross sectional area of the lower end of the whirl chamber.

3. In a water tube steam boiler, a steam and water drum subject to a wide range of water levels, steam generating tubes exposed to heat and discharging mixtures of steam and water into the drum at high velocity, a rowof steam and water separators within the drum with each separator constructed to provide a circular whirl chamber with an upper outlet whereby steam is vented into the steam space of the drum, means providing direct communication between said tubes and the inlets of the separators, and a cup-shaped member having an upwardly extending wall surrounding the lower end of the whirl chamber and of larger diameter than the whirl chamber so as to form therewith an outlet passage through which separated water is discharged into the drum, said member also forming the bottom of the whirl chamber, the discharge end of said outlet passage being limited to a zone adjacent the perimeter of the whirl chamber and being above the bottom of the whirl chamber so that the separator may operate effectively with drum Water levels considerably below the bottom of the separator, said outlet passage having a flow area less than the cross sectional area of the lower end .of the whirl