US2565933A - Ventilating exhaust structure - Google Patents

Ventilating exhaust structure Download PDF

Info

Publication number
US2565933A
US2565933A US16307A US1630748A US2565933A US 2565933 A US2565933 A US 2565933A US 16307 A US16307 A US 16307A US 1630748 A US1630748 A US 1630748A US 2565933 A US2565933 A US 2565933A
Authority
US
United States
Prior art keywords
intake
air
gas
column
curtain
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
US16307A
Inventor
Claude B Schneible
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to US16307A priority Critical patent/US2565933A/en
Application granted granted Critical
Publication of US2565933A publication Critical patent/US2565933A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F9/00—Use of air currents for screening, e.g. air curtains
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B15/00—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area
    • B08B15/02—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area using chambers or hoods covering the area
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/02—Ducting arrangements
    • F24F13/06—Outlets for directing or distributing air into rooms or spaces, e.g. ceiling air diffuser
    • F24F2013/0616—Outlets that have intake openings
    • 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
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S55/00—Gas separation
    • Y10S55/29—Air curtains

Definitions

  • This invention relates to a ventilating exhaust structure, and is particularly useful in the treatment of fumes, smoke, particle-laden gas, chemical vapors, etc.
  • gas as employed herein, I mean not only incondensable gaseous materials but condensable vapors, etc.
  • An object of the present invention is-to provide ventilating exhaust equipment, in which a curtain of air is employed in conjunction with the xhaust intake for guiding and directing gaseous materials,such as fumes, smoke, chemical vapors, and including fine particulate matter, etc., into the intake, while at the same time leaving an open space through which operators have access to castings and other sources of such gaseous materials, particulate matter, etc.
  • Yet another object is to provide, in conjunction with an exhaust intake, means for forming a blanket or curtain of air about an area in which there is present a source of gaseous material, etc, and thus enabling the intake of the exhaust to be positioned at a lower point in the room above the source of the gaseous material.
  • a still further object is to provide means for forming a gaseous curtain partially around or completely around an exhaust intake, whereby there is access to the source of the gaseous material from various sides thereof and while insuring that non-e of the gaseous material may escape into the room or building.
  • Figure 1 is a broken side view in elevation of apparatus embodying my invention
  • Fig. 2 a broken front View in elevation
  • Fig. 3 a sectional detail view, the section being taken as indicated at line 33 of Fig. 2
  • Fig. 4 a vertical sectional view of a. modified form of the invention.
  • I provide an exhaust conduit I0, provided with an exhaust fan I i, and having an intake 22.
  • the intake I2 is enclosed by a perimetric frame I3 supported by standards M, which are secured together by a rail l5 resting upon the floor IS.
  • the intake 12 is preferably provided with a plurality of spaced louvers H, which may be of any suitable shape, but preferably are of the crosssectional shape illustrated in Fig. 3. Louvers, such as are shown in Schneible Patent No. 2,277,271, are useful in connection with this apparatus.
  • a mold 2! is shown in a position adjacent the intake i2,'and the curtain of air from the discharge slot 20 forms a blanket about one side of the mold.
  • fumes, smoke, dust, etc., rising from the mold is prevented from going upward in a vertical direction and is required to enter the intake l2.
  • access to the mold may be had through the curtain of air.
  • the hoist line 22 may be lowered to bring the hook 23 into engagement with the loop of the mold 2! and in doing so, may pass directly through the curtain of air.
  • the operator can pass instruments through the curtain of air and can, in other ways, have direct access to the mold 2 l v
  • the discharge slot or opening 28 may be provided with parallel louvers or ribs to produce a longer stream or blanket of air.
  • Such detail structure is shown in co-pending application of Schneible and Lundy, Serial No. 788,496, for Treatment of Gas, and the Like.
  • the curtains of air may be formed on both sides of the mold, as shown more clearly in Fig. 4, and, if desired, may be caused to completely enclose the source of gaseous material from all sides.
  • I provide an outlet conduit 24 communicating with a central inlet or intake 25.
  • a discharge chamber 26 narrowed at its lower end for the discharge of a curtain of air along a side of the mold 2! below.
  • Inlet conduits 2! communicate with the chambers 26.
  • the structure described is supported upon standards 28.
  • a track 29 is supported upon a platform 30, and a vehicle 3
  • the air curtains diverge laterally and provide an enclosure which prevents the escape of gaseous material, which might ordinarily spread laterally as it rises.
  • the intake 25 is effective for withdrawing all of the material.
  • the operator has access to the mold 2
  • the discharge slots forming the air curtains actually form a part of the ventilating exhaust apparatus and, in efiect, discharge fluid forming side walls extending laterally and about the area holding the source of the contamination or other fluids, the walls being fluid and penetrable by the operator.
  • the air curtain is strongest at the upper point, where it emerges from the area about the intake and at the point where it is most important that the gaseous material does not break through.
  • the curtain of air descends, it turns inwardly to supply the carrier fluid used to withdraw the contaminant, etc.
  • the turning of the air curtain near its bottom provides the bulk of the carrier fluid which is necessary to act as the conveying means for removal of the contaminant, etc.
  • an exhaust conduit equipped with an intake extending at an inclination upwardly and inwardly toward said column, and a second conduit having a discharge opening adjacent an upper edge of said intake and directed outwardly and downwardly at an inclination and forming with said intake an inverted V canopy for directing the rising column of gas toward said intake.
  • an exhaust conduit equipped with means for maintaining a suction therein and provided with an inclined intake carried by said support, said intake extending upwardly and inwardly towards said column, louvers extending across said intake in spaced relation, a second conduit having a discharge outlet adjacent the upper edge of said intake, and means for discharging gas through said discharge opening, said discharge opening being directed across said column of gas.
  • an exhaust conduit equipped with means for maintaining a suction therein and provided with an inclined intake carried by said support, said intake extending upwardly and inwardly towards said column, louvers extending across said intake in spaced relation, a second conduit having a discharge outlet adjacent the upper edge of said intake, and means for discharging gas through said discharge opening, said discharge opening being directed across said column of gas and downwardly along the outer side thereof.
  • a casing providing an exhaust conduit equipped with an intake extending at an inclination upwardly and inwardly towards said column and providing also a second conduit having a discharge opening adjacent an upper edge of said intake and directed outwardly and downwardly at an inclination and forming with said intake an inverted V canopy for directing the rising column of gas towards said intake.
  • a casing providing an exhaust conduit equipped with means for maintaining a suction therein and provided with an inclined intake, said intake extending upwardly and inwardly towards said column, a bafile structure about the lower portion of said intake.
  • said casing providing also a second conduit having a discharge opening adjacent an upper edge of said intake and directed outwardly and downwardly at an inclination, and means for discharging gas through said discharge opening, said discharge opening being directed across said column of gas.

Description

Aug. 28, 1951 c. B. SCHNEIBLE 2,565,933
VENTILATING EXHAUST STRUCTURE Filed March 22, 1948 2 Sheets-Sheet 1 Aug. 28, 1951 c. B. SCHNEIBLE VENTILATING EXHAUST STRUCTURE Filed March 22, 19 1s 2 Sheets-Sheet 2 wm' V Patented Aug. 28, 1951 UNITED STATES PATENT OFFICE VENTILATING EXHAUST STRUCTURE Claude B. Schneible, Detroit,-Mich.
Application March 22, 1948, Serial No. 16,307
This invention relates to a ventilating exhaust structure, and is particularly useful in the treatment of fumes, smoke, particle-laden gas, chemical vapors, etc. By the term gas, as employed herein, I mean not only incondensable gaseous materials but condensable vapors, etc.
An object of the present invention is-to provide ventilating exhaust equipment, in which a curtain of air is employed in conjunction with the xhaust intake for guiding and directing gaseous materials,such as fumes, smoke, chemical vapors, and including fine particulate matter, etc., into the intake, while at the same time leaving an open space through which operators have access to castings and other sources of such gaseous materials, particulate matter, etc. Yet another object is to provide, in conjunction with an exhaust intake, means for forming a blanket or curtain of air about an area in which there is present a source of gaseous material, etc, and thus enabling the intake of the exhaust to be positioned at a lower point in the room above the source of the gaseous material. A still further object is to provide means for forming a gaseous curtain partially around or completely around an exhaust intake, whereby there is access to the source of the gaseous material from various sides thereof and while insuring that non-e of the gaseous material may escape into the room or building. Other specific objects and advantages will appear as the specification proceeds.
The invention is illustrated, in preferred embodiments, by the accompanying drawings, in which Figure 1 is a broken side view in elevation of apparatus embodying my invention; Fig. 2, a broken front View in elevation; Fig. 3, a sectional detail view, the section being taken as indicated at line 33 of Fig. 2; and Fig. 4, a vertical sectional view of a. modified form of the invention.
In the illustration given in Figs. 1 to 3, inclusive, I provide an exhaust conduit I0, provided with an exhaust fan I i, and having an intake 22. The intake I2 is enclosed by a perimetric frame I3 supported by standards M, which are secured together by a rail l5 resting upon the floor IS.
The intake 12 is preferably provided with a plurality of spaced louvers H, which may be of any suitable shape, but preferably are of the crosssectional shape illustrated in Fig. 3. Louvers, such as are shown in Schneible Patent No. 2,277,271, are useful in connection with this apparatus.
Immediately above the intake I2 is an inlet conduit l8 equipped with a discharge fan I 9, and having a wide and relatively narrow outlet 20 for 5 Claims. (Cl. 98115) discharging a thin blanket or curtain of air, as indicated by the arrows in Fig. 1.
In the specific illustration given in Fig. 1, a mold 2! is shown in a position adjacent the intake i2,'and the curtain of air from the discharge slot 20 forms a blanket about one side of the mold. Hence, fumes, smoke, dust, etc., rising from the mold is prevented from going upward in a vertical direction and is required to enter the intake l2. At the same time, access to the mold may be had through the curtain of air. For example, the hoist line 22 may be lowered to bring the hook 23 into engagement with the loop of the mold 2! and in doing so, may pass directly through the curtain of air. Similarly, the operator can pass instruments through the curtain of air and can, in other ways, have direct access to the mold 2 l v If desired, the discharge slot or opening 28 may be provided with parallel louvers or ribs to produce a longer stream or blanket of air. Such detail structure is shown in co-pending application of Schneible and Lundy, Serial No. 788,496, for Treatment of Gas, and the Like.
Instead of discharging an air curtain along one side only of the mold 2!, or other source of gaseous material, the curtains of air may be formed on both sides of the mold, as shown more clearly in Fig. 4, and, if desired, may be caused to completely enclose the source of gaseous material from all sides.
In thespecific illustration given in Fig. 4, I provide an outlet conduit 24 communicating with a central inlet or intake 25. On each side of the intake 25, there is provided a discharge chamber 26, narrowed at its lower end for the discharge of a curtain of air along a side of the mold 2! below. Inlet conduits 2! communicate with the chambers 26. The structure described is supported upon standards 28. A track 29 is supported upon a platform 30, and a vehicle 3| is provided for carrying the mold, or other source of gaseous material, into and out of the space controlled by the air curtains.
In the structure described in Fig. 4, the air curtains diverge laterally and provide an enclosure which prevents the escape of gaseous material, which might ordinarily spread laterally as it rises. By confining the gaseous material, as illustrated, the intake 25 is effective for withdrawing all of the material. At the same time, the operator has access to the mold 2|, or casting or other object carried by the vehicle 3|, even while the same is positioned below the intake 25.
With the structure described, it will be noted that the discharge slots forming the air curtains, actually form a part of the ventilating exhaust apparatus and, in efiect, discharge fluid forming side walls extending laterally and about the area holding the source of the contamination or other fluids, the walls being fluid and penetrable by the operator. With the structure shown, the air curtain is strongest at the upper point, where it emerges from the area about the intake and at the point where it is most important that the gaseous material does not break through. As the curtain of air descends, it turns inwardly to supply the carrier fluid used to withdraw the contaminant, etc. The turning of the air curtain near its bottom provides the bulk of the carrier fluid which is necessary to act as the conveying means for removal of the contaminant, etc.
While in the foregoing-specification, I have set forth specific structures in considerable detail for the purpose of illustrating embodiments of my invention, it will be understood that such details of structure may be modified widely by those skilled in the art without departing from the spirit of my invention.
I claim:
1. In ventilating exhaust apparatus for treating a rising column of gas, an exhaust conduit equipped with an intake extending at an inclination upwardly and inwardly toward said column, and a second conduit having a discharge opening adjacent an upper edge of said intake and directed outwardly and downwardly at an inclination and forming with said intake an inverted V canopy for directing the rising column of gas toward said intake.
2. In ventilating exhaust apparatus for treating a column of gas rising from a grate, a support extending upwardly at one side of said grate,
an exhaust conduit equipped with means for maintaining a suction therein and provided with an inclined intake carried by said support, said intake extending upwardly and inwardly towards said column, louvers extending across said intake in spaced relation, a second conduit having a discharge outlet adjacent the upper edge of said intake, and means for discharging gas through said discharge opening, said discharge opening being directed across said column of gas.
3. In ventilating exhaust apparatus for treating a column of gas rising from a grate, a support extending upwardly at one side of said grate,
4 an exhaust conduit equipped with means for maintaining a suction therein and provided with an inclined intake carried by said support, said intake extending upwardly and inwardly towards said column, louvers extending across said intake in spaced relation, a second conduit having a discharge outlet adjacent the upper edge of said intake, and means for discharging gas through said discharge opening, said discharge opening being directed across said column of gas and downwardly along the outer side thereof.
4. In ventilating exhaust apparatus for treating a rising column of gas, a casing providing an exhaust conduit equipped with an intake extending at an inclination upwardly and inwardly towards said column and providing also a second conduit having a discharge opening adjacent an upper edge of said intake and directed outwardly and downwardly at an inclination and forming with said intake an inverted V canopy for directing the rising column of gas towards said intake. 1
5. In ventilating exhaust apparatus for treating a rising column of gas, a casing providing an exhaust conduit equipped with means for maintaining a suction therein and provided with an inclined intake, said intake extending upwardly and inwardly towards said column, a bafile structure about the lower portion of said intake. said casing providing also a second conduit having a discharge opening adjacent an upper edge of said intake and directed outwardly and downwardly at an inclination, and means for discharging gas through said discharge opening, said discharge opening being directed across said column of gas.
' CLAUDE B. SCHNEIBLE.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,254,725 Pennock Jan, 29, 1918 1,577,509 Witham Mar. 23, 1926 2,210,458 Keilholtz Aug. 6, 1940 2,257,516 Roche Sept. 30, 1941 2,277,271 Schneible Mar. 24, 1942 2,438,606 I-Iulton Mar. 30, 1948 2,440,692 Kruse May 4, 1948 2,467,505 Sidell Apr. 19, 1949
US16307A 1948-03-22 1948-03-22 Ventilating exhaust structure Expired - Lifetime US2565933A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16307A US2565933A (en) 1948-03-22 1948-03-22 Ventilating exhaust structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US16307A US2565933A (en) 1948-03-22 1948-03-22 Ventilating exhaust structure

Publications (1)

Publication Number Publication Date
US2565933A true US2565933A (en) 1951-08-28

Family

ID=21776466

Family Applications (1)

Application Number Title Priority Date Filing Date
US16307A Expired - Lifetime US2565933A (en) 1948-03-22 1948-03-22 Ventilating exhaust structure

Country Status (1)

Country Link
US (1) US2565933A (en)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756617A (en) * 1953-07-27 1956-07-31 Wyman Gordon Co Ventilating system for forging presses
US2810337A (en) * 1956-01-10 1957-10-22 Petrolite Corp Ventilated fume hoods
US2908212A (en) * 1957-09-30 1959-10-13 Ross Engineering Of Canada Ltd Vapor confining air curtain for paper machines
US3023688A (en) * 1958-05-16 1962-03-06 Jr Fred A Kramer Air barrier
US3368474A (en) * 1966-11-09 1968-02-13 Nashua Wood Products Inc Air venting system
US3411428A (en) * 1966-06-27 1968-11-19 Willard K. Ahlrich Ventilating hood for food cooking device
US3421290A (en) * 1967-02-16 1969-01-14 United Air Specialists Indoor smoke removal system
DE1289974B (en) * 1964-11-07 1969-02-27 Siemens Elektrogeraete Gmbh Device for extracting air with undesired admixtures
US3444802A (en) * 1967-02-23 1969-05-20 Ionic International Inc Forced air curtain wall for hoist and auxiliary equipment
US3513766A (en) * 1968-06-24 1970-05-26 Willard K Ahlrich Ventilating hood
US3592121A (en) * 1969-06-23 1971-07-13 Claude B Schneible Co Compensating hood apparatus
US3895569A (en) * 1973-09-26 1975-07-22 Ind Clean Air Inc Air modulating fume system
US5613990A (en) * 1995-03-28 1997-03-25 Helical Dynamics, Inc. Air cleaning system for mechanical industrial processes
US5716268A (en) * 1997-02-18 1998-02-10 Plymovent Ab Device for removal of deleterious impurities from room atmosphere
US20050161861A1 (en) * 2003-09-26 2005-07-28 Brunswick Corporation Apparatus and method for making preforms in mold

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1254725A (en) * 1916-08-16 1918-01-29 Western Electric Co Vapor and fume controlling system.
US1577509A (en) * 1922-04-10 1926-03-23 American Blower Co Apparatus for handling vapors
US2210458A (en) * 1936-11-16 1940-08-06 Lester S Keilholtz Method of and apparatus for air conditioning
US2257516A (en) * 1938-03-01 1941-09-30 Binks Mfg Co Operator-protecting spray booth
US2277271A (en) * 1938-10-21 1942-03-24 Claude B Schneible Ventilator for dust creating operations
US2438606A (en) * 1944-03-16 1948-03-30 Kirk & Blum Mfg Company Pneumatic canopy
US2440692A (en) * 1942-07-06 1948-05-04 American Can Co Cooling chamber having baffles for directing air over dried material
US2467505A (en) * 1944-09-25 1949-04-19 American Machine & Metals Fume exhaust system

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1254725A (en) * 1916-08-16 1918-01-29 Western Electric Co Vapor and fume controlling system.
US1577509A (en) * 1922-04-10 1926-03-23 American Blower Co Apparatus for handling vapors
US2210458A (en) * 1936-11-16 1940-08-06 Lester S Keilholtz Method of and apparatus for air conditioning
US2257516A (en) * 1938-03-01 1941-09-30 Binks Mfg Co Operator-protecting spray booth
US2277271A (en) * 1938-10-21 1942-03-24 Claude B Schneible Ventilator for dust creating operations
US2440692A (en) * 1942-07-06 1948-05-04 American Can Co Cooling chamber having baffles for directing air over dried material
US2438606A (en) * 1944-03-16 1948-03-30 Kirk & Blum Mfg Company Pneumatic canopy
US2467505A (en) * 1944-09-25 1949-04-19 American Machine & Metals Fume exhaust system

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756617A (en) * 1953-07-27 1956-07-31 Wyman Gordon Co Ventilating system for forging presses
US2810337A (en) * 1956-01-10 1957-10-22 Petrolite Corp Ventilated fume hoods
US2908212A (en) * 1957-09-30 1959-10-13 Ross Engineering Of Canada Ltd Vapor confining air curtain for paper machines
US3023688A (en) * 1958-05-16 1962-03-06 Jr Fred A Kramer Air barrier
DE1289974B (en) * 1964-11-07 1969-02-27 Siemens Elektrogeraete Gmbh Device for extracting air with undesired admixtures
US3411428A (en) * 1966-06-27 1968-11-19 Willard K. Ahlrich Ventilating hood for food cooking device
US3368474A (en) * 1966-11-09 1968-02-13 Nashua Wood Products Inc Air venting system
US3421290A (en) * 1967-02-16 1969-01-14 United Air Specialists Indoor smoke removal system
US3444802A (en) * 1967-02-23 1969-05-20 Ionic International Inc Forced air curtain wall for hoist and auxiliary equipment
US3513766A (en) * 1968-06-24 1970-05-26 Willard K Ahlrich Ventilating hood
US3592121A (en) * 1969-06-23 1971-07-13 Claude B Schneible Co Compensating hood apparatus
US3895569A (en) * 1973-09-26 1975-07-22 Ind Clean Air Inc Air modulating fume system
US5613990A (en) * 1995-03-28 1997-03-25 Helical Dynamics, Inc. Air cleaning system for mechanical industrial processes
US5658373A (en) * 1995-03-28 1997-08-19 Helical Dynamics, Inc. Air cleaning methods for mechanical industrial process
US5716268A (en) * 1997-02-18 1998-02-10 Plymovent Ab Device for removal of deleterious impurities from room atmosphere
US20050161861A1 (en) * 2003-09-26 2005-07-28 Brunswick Corporation Apparatus and method for making preforms in mold

Similar Documents

Publication Publication Date Title
US2565933A (en) Ventilating exhaust structure
EP0323961B1 (en) An improved fluid barrier curtain system
US3111077A (en) Convertible fumehood
JPH02145685A (en) Method and device for cooling coke oven ceiling and adjacent area and for keeping them clean
US3000292A (en) Fume hood
US2074317A (en) Recirculating air system for dust removal
KR920017201A (en) Vertical Heat Treatment Equipment
KR870000956A (en) Drying or cooling method of granular material in a mixer, and apparatus
US3425335A (en) Laboratory fume hood
US3747504A (en) Fume hood
JPS58500178A (en) Clean room and its operating method
US3356006A (en) Clean room structure
US3442230A (en) Worktable
US2579401A (en) Gas treating apparatus and method
US2438606A (en) Pneumatic canopy
ATE37668T1 (en) DEVICE FOR TREATMENT OF SUBSTANCES IN A GAS FLOW.
US2567776A (en) Treatment of gas and the like
JPS57139233A (en) Moving operation chamber with carbon monoxide removing device
US2277271A (en) Ventilator for dust creating operations
US2082374A (en) Exhaust ventilating hood for industrial and other purposes
US3897229A (en) Dual action laminar air flow
US2942540A (en) Gas fractionating apparatus
US2683958A (en) Compensating and fractionating swing grinder hood
US2704973A (en) Ventilating system
US2589149A (en) Apparatus for treatment of gas