US3575387A - Air control damper for evaporative heat exchangers - Google Patents

Air control damper for evaporative heat exchangers Download PDF

Info

Publication number
US3575387A
US3575387A US781348A US3575387DA US3575387A US 3575387 A US3575387 A US 3575387A US 781348 A US781348 A US 781348A US 3575387D A US3575387D A US 3575387DA US 3575387 A US3575387 A US 3575387A
Authority
US
United States
Prior art keywords
damper
sump
air
ducting
improvement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US781348A
Other languages
English (en)
Inventor
Wilson E Bradley Jr
Edward N Schinner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baltimore Aircoil Co Inc
Original Assignee
Baltimore Aircoil Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Baltimore Aircoil Co Inc filed Critical Baltimore Aircoil Co Inc
Application granted granted Critical
Publication of US3575387A publication Critical patent/US3575387A/en
Assigned to FIRST NATIONAL BAK OF CHICAGO, THE reassignment FIRST NATIONAL BAK OF CHICAGO, THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BALTIMORE AIRCOIL COMPANY, INC., A CORP. OF DE.
Anticipated expiration legal-status Critical
Assigned to BALTIMORE AIRCOIL COMPANY, INC. reassignment BALTIMORE AIRCOIL COMPANY, INC. RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: FIRST NATIONAL BANK OF CHICAGO, THE
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/44—Fluid-guiding means, e.g. diffusers
    • F04D29/46—Fluid-guiding means, e.g. diffusers adjustable
    • F04D29/462—Fluid-guiding means, e.g. diffusers adjustable especially adapted for elastic fluid pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
    • F04D27/02—Surge control
    • F04D27/0253—Surge control by throttling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28C—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA COME INTO DIRECT CONTACT WITHOUT CHEMICAL INTERACTION
    • F28C1/00—Direct-contact trickle coolers, e.g. cooling towers
    • F28C1/02—Direct-contact trickle coolers, e.g. cooling towers with counter-current only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F25/00—Component parts of trickle coolers
    • F28F25/10—Component parts of trickle coolers for feeding gas or vapour
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F25/00—Component parts of trickle coolers
    • F28F25/10—Component parts of trickle coolers for feeding gas or vapour
    • F28F25/12—Ducts; Guide vanes, e.g. for carrying currents to distinct zones
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00—Geometry
    • F05D2250/50—Inlet or outlet
    • F05D2250/52—Outlet
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Definitions

  • This application relates to blowthrough type evaporative heat exchangers and, more particularly, to improved equipment for controlling the flow of air to the heat exchange region of such heat exchangers.
  • Evaporative heat exchangers are devices in which air and water are flowed in countercurrent or other contact relation through a heat exchange region. A small portion of thewater variations; and the equipment is subject to variations in the heat load with which it is required to deal. Thus, on a cool day with a full heat load or on a warm day with a light heat load or a combination of both, the equipment has an excess of cooling capacity. To reduce the amount of cooling capacity to meet a low load and/or cool air condition, .a usual. procedure is to reduce the amount of air flow through the heat exchange region. For very complete control the air flow should be capable of being greatly reduced, for example by as much as 80 to 90 percent.
  • V-section sump has numerous advantages such as reduced water inventory, reduced weight, greatly facilitated shipping capability, and so forth, a consequence of the use of the' V-sump is that the ducting for the air blowers is required to be both substantially shorter and differently arranged than was the case with the blow-through evaporative heat exchanger having sumps of conventional configuration. It has been found, for example, that the conventional damper as disclosed in said l-Iollingsworth U.S. Pat. No.
  • 2,7 l9,666 has a tendency to cause water leakage into the ducting around its operating shaft and to cause the fan duct to aspirate water if it is located inside the sloping plane of the sump wall of the V-type unit and, even if moved outside that wall still causes aspiration of water and additionally interferes with air flow when the damper is in the maximum flow position. Because of the substantially shorter length of the diffusion ducting between the outlet of the centrifugal blowers and the plane of air discharge within the sump, the eddy currents which are produced by thedamper create regions of pressure at the mouth of the air duct which are negative relative to the sump pressure resulting in aspiration of water into the fan region to the detriment of its performance and durability.
  • the damper may be controlled and moved through the full range of positions from a full open position to a maximum choke position under conditions which avoid aspiration of water into the fan housing through the mouth of the air fan duct as well as shaft leakage problems.
  • FIG. 1 is a view in vertical section of a cooling tower having a V sump of the type shown in application Ser. No. 706,003, filed Feb. 16, I968, now U.S. Pat. No. 3,442,494, incorporating an improved air control damper constructed in accordance with theteachings of the present invention;
  • FIG. 2 is a fragmentary view in vertical section to an enlarged scale of the centrifugal-blower, ducting and damper incorporated in the cooling tower of FIG. 1, the damper being shown in the full open position;
  • FIG. 3 is a view in vertical section and to an enlarged scale illustratingthe maximum choke position of a damper of the type shown in FIG. ll;
  • FIG. 4 is a fragmentary view in vertical section to an enlarged scale of a modified type of damper constructed in accordance with the teachings of the present invention, the damper being shown in themaximum choke position'and the full open position being indicated in'broken lines; and
  • FIG. 5 is a fragmentary view in section taken on the line 5-5 of FIG. 4.
  • FIG. 1 illustrates a cooling tower of the type disclosed and claimed in application Ser. No. 706,003, filed Feb. 16, I968 now U.S. Pat. No. 3,442,494.
  • This cooling tower comprises a water spray section 10 below' which are located heat exchange regions 11 occupied with fill functioning to present a large surface area for water-air contact.
  • the sump I3 is defined by two triangular vertical walls 14, one of which shows in FIG. I, a vertical, rectangular wall 15 and a sloping wall 16.
  • the walls l4, l5, and 16 define, in effect, a trough having a cross section in the form of a V.
  • a centrifugal blower. 1-7 is located beneath the sloping wall 16 of the sump l3 and air ducting 18 connects the'outlet of the: housing of the blower 17 with the interior of the sump region 13.
  • the ducting l8 terminates at a mouth 19 which lies within the sump l3'above the level of water therein.
  • the function of the apparatus of FIG. 1 is to extract heat from water.
  • water which is to have heat extractedfrom it is introduced into the coolingtower at a header 20from which there extend a large number of spaced parallel pipes 21 covering the cross-sectional area of the region 10.
  • Each pipe 21 is fitted with a plurality of nozzles 22 and from the various nozzles 22 water is discharged. to gravitate through regions 11 and 12 and into the sump 13.
  • the water falls through the regions 11 and 12
  • it is contacted by counter flowing air moving upwardly from the fan mouth 19 through the cooling tower.
  • the air-water contact causes evaporation of some of the water and the latent heat of vaporization is extracted from the remainder of the water resulting in cooling of the same.
  • Mist eliminators 23 function to prevent the'upflowing air from driving mist out of the top of the cooling tower.
  • the water from which heat has been extracted is collected in the bottom of the sump and is withdrawn through a conduit 24 to a point of use.
  • makeup water is added to the system as needed by conventional means, not shown.
  • the sump is provided with a battle at 25 to stabilize the water level against the influences of the withdrawal of'water and the impingement of air on the upper surface of it.
  • a baffle 26 is located in the region 12 and functions. to assist in distributing air uniformly across the cross section of the.
  • the fill region 11 is made up of modular units which are disclosed and claimed in application Ser. No. 706,004, filed- Feb. 16, I968; For purposes of the present invention, it
  • FIG. 2 shows the blower 17 to a much enlarged scale and in that FIG. most of the remaining structure of the cooling tower is omitted for convenience of illustration.
  • the blower I7 is of the centrifugal type having a center air inlet at 28 and blades 29 which discharge the air into the blower housing 30.
  • the blower housing 30 is of generally rectangular cross section defined by two vertical walls 31 (one of which shows in FIG.
  • the air discharge duct 18 is supported from sloping wall 16 of the sump I3 and provides a continuing ducted air path of rectangular cross section between the end of the fan housing 30 and duct mouth 19 which is located within the sump area. Note that the discharge end of the fan housing 30 telescopes into the ducting 18. Some additional diffusion occurs between the end of the fan housing and the mouth 19 of the ducting 18 so that the air issuing from the ducting 18 has had some of the energy which has been put into it by the blower 17 converted from dynamic to static form.
  • the air issuing from the mouth I9 of ducting 18 would flow to the mouth in a direction generally as indicated by the arrows in FIG. 2.
  • the heat load is low or when the ambient air is cool or both when the unit has overcapacity which makes it desirable to operate the cooling tower with a reduced flow of air.
  • a sheet metal damper 34 made of a curved piece of metal 34a and a chordwise piece 34b connected to an operating shaft 35 which passes through the walls 31 to a point where angular displacement of the shaft 35 can be initiated.
  • a stationary baffle 38 is located downstream of the axis of the damper 34 and this baffle acts to subdivide the stream issuing through the space at 37 to promote better distribution of the air across the cross section of the duct 18. In effect, the streams passing through regions 36 and 37 are caused to merge enough before the mouth I9 of duct 18 is reached so that an even enough pressure front is presented to prevent water aspiration.
  • the damper 34 is so shaped and located as to ofier virtually no interference to the air flow when it is in the FIG. 2 position.
  • the baffle 38 which extends between the walls 33 of the air duct in a plane substantially parallel to the plane of the air issuing from the blades of the blower.
  • bafiIe 34 When bafiIe 34 is in the FIG. 3 position, however, it tends to drive the air back into the impeller blades 29 greatly to decrease the output of the blower. Furthermore, the air which does pass through the space at 37 is not moving in the same direction as is the case when the damper 34 is in the FIG. 2 position so that now the baffle 38 forms a stream dividing function.
  • ducting l8 and blower housing 30 may be made as shown in FIG. 2. However, any construction can be used so long as a continuous ducting surrounds the blower rotor, extends through the sump wall, and terminates in a discharge mouth within the sump region.
  • FIG. 4 there is shown a modified damper constructed in accordance with the teachings of the present invention but again offering negligible resistance to the air flow in the open position but permitting, in the maximum choke position, as much as to percent reduction in air flow.
  • the ducting and blower are much the same as those described in FIGS. 1 to 3, inclusive, except that the blower rotor 40 is of larger capacity and hence of larger diameter and therefore has to be placed with its periphery closer to the sloping sump wall 41 than is the case with blower rotor 28 and sump wall 16.
  • FIG. 4 As is the case with the FIG.
  • a damper 44 made of two sheet metal pieces 44a and 44b is fixed to rotate with a shaft 45 which extends through the sidewalls 46 of the fan housing 42.
  • the damper 44 is movable from the full open broken line position to the maximum choke full line position of FIG. 4 by operation of the shaft 45.
  • damper 34 there is an air passage at 47 between the damper 44 and the outer curved wall 48 of the fan housing 42, and there is another space 49 between the other end of the damper and the periphery of the rotor 40.
  • baffle is in the form of two rods 50 and 51 which extend between the sidewalls 52 and 53 of ducting 43, see FIG. 5. Again, the air streams are distributed so that there is a substantially positive pressure front across the ducting 43 at its mouth 54.
  • an evaporative heat exchanger having a sump for receiving water gravitating from a heat exchange region, a wall partially defining said sump, a centrifugal blower located outside said sump, air ducting surrounding said blower, passing through said wall and presenting an air discharge mouth within the sump
  • the improvement that comprises, a damper located in said ducting, means mounting said damper for movement from a full open position in which it lies substantially parallel to the air flow in the region where it is located to a maximum choke position in which it passes at least one stream of air and means downstream of said damper to modify the direction of said airstream to distribute the air across the full cross section of the ducting mouth evenly enough to prevent water aspiration.
  • an evaporative heat exchanger having a sump for receiving water gravitating from a heat exchange region, a sloping wall partially defining said sump, a centrifugal blower located outside said sump, air ducting surrounding said blower, passing through said wall and presenting an air discharge mouth within the sump
  • the improvement that comprises, a damper located in said ducting on the same side of said sloping wall as said centrifugal blower, means mounting said damper for movement from a full open position in which it lies substantially parallel to the air flow in the region where it is located to a maximum choke position in which it passes at least one stream of air and means downstream of said damper to modify the direction of said airstream to distribute the air across the full cross section of the ducting mouth evenly enough to prevent water aspiration.
  • an evaporative heat exchanger having a sump for receiving water gravitating from a heat exchange region, a sloping wall partially defining said sump, a centrifugal blower located outside said sump, air ducting surrounding said blower, passing through said wall and presenting an air discharge mouth within the sump
  • the improvement that comprises, a damper located in said ducting on the same side of said sloping wall as said centrifugal blower, means mounting said damper for movement from a full open position in which it lies substantially parallel to the air flow in the region where it is located to a maximum choke position in which it passes at least two streams of air and means 7.
  • the means downstream of said damper is a pair of rods extending across the airstream.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
US781348A 1968-12-05 1968-12-05 Air control damper for evaporative heat exchangers Expired - Lifetime US3575387A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US78134868A 1968-12-05 1968-12-05

Publications (1)

Publication Number Publication Date
US3575387A true US3575387A (en) 1971-04-20

Family

ID=25122431

Family Applications (1)

Application Number Title Priority Date Filing Date
US781348A Expired - Lifetime US3575387A (en) 1968-12-05 1968-12-05 Air control damper for evaporative heat exchangers

Country Status (8)

Country Link
US (1) US3575387A (enrdf_load_stackoverflow)
BE (1) BE730787A (enrdf_load_stackoverflow)
CH (1) CH501199A (enrdf_load_stackoverflow)
DE (1) DE1909208A1 (enrdf_load_stackoverflow)
ES (1) ES363924A1 (enrdf_load_stackoverflow)
FR (1) FR2025359A1 (enrdf_load_stackoverflow)
GB (1) GB1233885A (enrdf_load_stackoverflow)
SE (1) SE353146B (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996314A (en) * 1974-05-30 1976-12-07 I.C.M.S. Ltd. Cooling apparatus
US4708826A (en) * 1985-03-06 1987-11-24 Sharp Kabushiki Kaisha Supersonic humidifier
US5663536A (en) * 1995-10-10 1997-09-02 Amsted Industries Incorporated Sound attenuation assembly for air-cooling apparatus
US6574980B1 (en) 2000-09-22 2003-06-10 Baltimore Aircoil Company, Inc. Circuiting arrangement for a closed circuit cooling tower
WO2009091481A1 (en) * 2008-01-18 2009-07-23 Spx Cooling Technologies, Inc. Heat exchange tower airflow apparatus and method
CN103234371A (zh) * 2013-05-31 2013-08-07 无锡禹兵冷却设备有限公司 双冷式闭式冷却系统
CN103234370A (zh) * 2013-05-31 2013-08-07 无锡禹兵冷却设备有限公司 轻便型闭式冷却塔
US20170153048A1 (en) * 2014-05-13 2017-06-01 Klaas Visser Improved Evaporative Condenser
WO2019028119A1 (en) * 2017-08-01 2019-02-07 Evapco, Inc. BIDIRECTIONAL TRIM FOR USE IN COOLING TOWERS
US20230057244A1 (en) * 2020-01-17 2023-02-23 Itm Power (Trading) Limited Electrochemical cell plant

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2374130A (en) * 1941-10-08 1945-04-17 Planiol Andre Paul Eugene Charge feeding system for internalcombustion engines
US3169575A (en) * 1961-10-27 1965-02-16 Baltimore Aircoil Co Inc Evaporative heat exchanger

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1948980A (en) * 1930-08-22 1934-02-27 Cooling Tower Co Inc Cooling tower
US2719666A (en) * 1952-03-14 1955-10-04 Holly Mfg Company Regulator device for a centrifugal blower
US2902209A (en) * 1956-08-24 1959-09-01 Mcclatchie Samuel Foster Flow throttling controls for blowers, turbines and the like
US3365909A (en) * 1966-06-15 1968-01-30 Borg Warner Evaporative cooling device bleed water arrangement

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2374130A (en) * 1941-10-08 1945-04-17 Planiol Andre Paul Eugene Charge feeding system for internalcombustion engines
US3169575A (en) * 1961-10-27 1965-02-16 Baltimore Aircoil Co Inc Evaporative heat exchanger

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996314A (en) * 1974-05-30 1976-12-07 I.C.M.S. Ltd. Cooling apparatus
US4708826A (en) * 1985-03-06 1987-11-24 Sharp Kabushiki Kaisha Supersonic humidifier
US5663536A (en) * 1995-10-10 1997-09-02 Amsted Industries Incorporated Sound attenuation assembly for air-cooling apparatus
US6574980B1 (en) 2000-09-22 2003-06-10 Baltimore Aircoil Company, Inc. Circuiting arrangement for a closed circuit cooling tower
WO2009091481A1 (en) * 2008-01-18 2009-07-23 Spx Cooling Technologies, Inc. Heat exchange tower airflow apparatus and method
US8088202B2 (en) 2008-01-18 2012-01-03 Spx Cooling Technologies, Inc. Heat exchange tower airflow apparatus and method
CN101918782B (zh) * 2008-01-18 2012-08-15 Spx冷却技术公司 热交换塔气流装置和方法
CN103234371A (zh) * 2013-05-31 2013-08-07 无锡禹兵冷却设备有限公司 双冷式闭式冷却系统
CN103234370A (zh) * 2013-05-31 2013-08-07 无锡禹兵冷却设备有限公司 轻便型闭式冷却塔
US20170153048A1 (en) * 2014-05-13 2017-06-01 Klaas Visser Improved Evaporative Condenser
WO2019028119A1 (en) * 2017-08-01 2019-02-07 Evapco, Inc. BIDIRECTIONAL TRIM FOR USE IN COOLING TOWERS
US20230057244A1 (en) * 2020-01-17 2023-02-23 Itm Power (Trading) Limited Electrochemical cell plant

Also Published As

Publication number Publication date
CH501199A (fr) 1970-12-31
DE1909208A1 (de) 1970-09-03
SE353146B (enrdf_load_stackoverflow) 1973-01-22
ES363924A1 (es) 1971-01-01
BE730787A (enrdf_load_stackoverflow) 1969-09-30
GB1233885A (enrdf_load_stackoverflow) 1971-06-03
DE1909208B2 (enrdf_load_stackoverflow) 1974-05-09
DE1909208C3 (enrdf_load_stackoverflow) 1974-12-12
FR2025359A1 (enrdf_load_stackoverflow) 1970-09-11

Similar Documents

Publication Publication Date Title
US4226282A (en) Heat exchange apparatus utilizing thermal siphon pipes
US3575387A (en) Air control damper for evaporative heat exchangers
US3903212A (en) Fan-assisted cooling tower and method of operation
US3800553A (en) Injector type indirect evaporative condensers
US3437319A (en) Evaporative heat exchanger with airflow reversal baffle
ES441258A1 (es) Una instalacion para cambiar la temperatura de medios flui- dos.
JP2795701B2 (ja) 送風機用遷移ダクト
US2941382A (en) Condensate disposal means for selfcontained air conditioners
US2346410A (en) Unit heater
US3899553A (en) Cooling tower plume control
US4156706A (en) Fan cylinder having invisible eased inlet
US3785625A (en) Injector type evaporative heat exchanger
US3595308A (en) Apparatus for cooling liquids
US4687603A (en) Cooling tower
US3442494A (en) Evaporative heat exchange apparatus
CN112484525B (zh) 自然通风与强制通风耦合湿式冷却塔及冷却方法
US4159738A (en) Fan-assisted forced flow air-cooling heat exchanger system
US4400185A (en) Evaporative cooler with improved air handling mechanism
US3749379A (en) System for thermal exhaust
GB1462901A (en) Heat exchangers
US2518760A (en) Air-cooled heat exchanger
US2258790A (en) Air tempering device
US2959031A (en) Self-contained air conditioning units
US3209668A (en) Air conditioning unit
GB1220884A (en) Evaporative heat exchange apparatus

Legal Events

Date Code Title Description
AS Assignment

Owner name: FIRST NATIONAL BAK OF CHICAGO, THE,ILLINOIS

Free format text: SECURITY INTEREST;ASSIGNOR:BALTIMORE AIRCOIL COMPANY, INC., A CORP. OF DE.;REEL/FRAME:004520/0644

Effective date: 19860304

Owner name: FIRST NATIONAL BAK OF CHICAGO THE ONE FIRST NATION

Free format text: SECURITY INTEREST;ASSIGNOR:BALTIMORE AIRCOIL COMPANY, INC., A CORP. OF DE.;REEL/FRAME:004520/0644

Effective date: 19860304

AS Assignment

Owner name: BALTIMORE AIRCOIL COMPANY, INC., MARYLAND

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:FIRST NATIONAL BANK OF CHICAGO, THE;REEL/FRAME:005091/0567

Effective date: 19880831