US3568415A - Fire control for filterhouse - Google Patents

Abstract

A FIRE CONTROL SYSTEM FOR A BAG FILTERHOUSE WHICH AUTOMATICALLY PROJECTS A FIRE EXTINGUISHING SUBSTANCE ONTO A FIRE BURNING WITHIN THE FILTERHOUSE. THE FIRE CONTROL SYSTEM IS UNIQUELY ADAPTED TO UTILIZE AN EXISTING AIR JET SYSTEM OF BAG CLEANING THEREBY MAKING AVAILABLE AN EFFECTIVE FIRE CONTROL SYSTEM AT VERY MINOR ADDITIONAL EXPENSE OF SPACE AND MATERIALS.

Description

March 9, 1971 D 1, WYROUGH 3,568,415

FIRE CONTROL FOR FILTERHOUSE Filed April 2,5. 1969 1 l Pm- INVEN'l'oR. al//c/ J /4/g//0ag United States Patent O 3,568,415 FIRE CONTROL FOR FILTERHOUSE David J. Wyrough, Wellsville, N.Y., assignor to The Air Preheater Company, Inc., Wellsville, N.Y. Filed Apr. 25, 1969, Ser. No. 819,289 Int. Cl. B01d 46/04 US. Cl. 55-302 4 Claims ABSTRACT OF THE DISCLOSURE A fire control system for a bag filterhouse which automatically projects a fire extinguishing substance onto a fire burning within the filterhouse. The fire control system is uniquely adapted to utilize an existing air jet system of bag cleaning thereby making available an effective fire control system at very minor additional expense of space and materials.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION This invention therefore provides a fire extinguishing system for a bag filterhouse where a fire extinguishing substance may be effectively presented to a multiplicity of locations where the burning of combustible filtrate has commenced.

The invention utilizes the same equipment for the presentation of the fire extinguishing material that already is normally used for periodic bag cleaning, thus an effective fire control system is readily provided for a bag filterhouse using an already existing air jet system of cleaning.

BRIEF DESCRIPTION OF THE DRAWING The single figure of the drawing is a cross-sectional view of a bag type cleaning apparatus constructed in accordance with the teachings of this invention.

THE SPECIFICATION In the drawing a housing has an inlet 12 for dust bearing gas and an outlet 14 for the exhaust of clean gas therefrom. The housing is separated into upper and lower portions by a tube sheet 16y having a series of ports 18 therein. The ports are surrounded by an annular collar 22 to which are clamped bag filters 24 of the customary form. A skeletal cage or support 26 inside each bag filter prevents excess pressure on the outside surface of the bag from causing the bag to collapse inwardly.

A series of nozzles 28 are connected to a manifold from which compressed air is exhausted into the open end of each filter bag 24. As the compressed air is exhausted into the open end of each bag, the excess pressure thereof causes a momentary halt to the flow through the bag filter of the air to be cleaned, the bag fiexes slightly outward, the dust cake on the outer surface thereof is broken loose and it falls to` the bottom of hopper 36 where it may be removed through door 38.

The valve 42 controlling the flow of air for cleaning the bags is intermittently controlled by the timer 44 connected to an electrical source 46. Positioned in the electrical circuit intermediate the timer 44 and the source of electrical energy 46 is a meltable fuse-valve 48 controlling flow in the duct 52 leading to the manifold 32. A source of fire extinguishing material, such as carbon tetrachloride, is connected to the duct 52 under pressure whereby opening the fuse valve 48 will permit the fire extinguishing material to flow to the duct 32 and the dependent nozzles 28 so that such fire extinguishing material will be exhausted into the open end of each bag 24.

Inasmuch as the dust cake collected on each bag frequently is extreme-ly fiammable, my invention provides an arrangement by which a fire of the collected dust particles on the surface of the bags or in another portion of the lter chamber may be quickly smoothered by a blast of fire extinguishing material directed into the open end of each bag 24.

In accordance with my invention I provide a source of pressurized fire extinguishing ma-terial 52 connected to the supply duct or manifold 32 leading to each nozzle 28. A meltable fuse-valve 48 located in the duct leading from the source 52 to the duct 32 is set to remain normally closed whereby the fire extinguishing material is normally excluded from the duct 32 and its connecting nozzles. Should a fire occur within the housing, the temperature would rise somewhat and the fuse-valve would consequently melt at a predetermined temperature. As the fuse-valve 48 would melt, the source of electrical energy operating the timer 44 woud be interrupted and the normally closed valve 42 would close to halt the fiow of air to the bag filters until such time as the apparatus could be completely re-set.

As the fuse-valve 48 melts to open the passageway to the duct 32, pressurized fire extinguishing fluid would be exhausted from each nozzle, and any fire in the filter bags would be quickly subjected to the fire extinguishing fluid. Simultaneously, the source of air normally used for bag cleaning would be cut off by closure of the valve 42. Although not illustrated in the drawing, a similar valve may be placed in the inlet duct 12 to be controlled by the same fuse 42 whereby its melting would permit the valve in duct 12 to close and completely close off the chamber within housing 10 to a source of air.

More rapid response to a rise of temperature in housing 10 may be realized if the fuse-valve 48 is located on the underside of the tube sheet 16 where the threat of potential burning is greatest and a temperature rise from burning material would be most quickly detected. This and various other changes may be made in the device without departing from the spirit of the invention. It is accordingly intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A bag filter apparatus for filtering solids from a gas carrier comprising a filter housing enclosing a filter compartment having an inlet for gas to be filtered and an outlet for the exhaust of clean gas therefrom, a filter bag with an open end and a closed end arranged to lie intermediate the inlet and the outlet of the filter housing means supporting the filter bag at its open end for preventing by-pass of the filter bag, cleaning means for the filter bag comprising a nozzle aligned with and directed towards the open end of the filter bag for exhausting cleaning gas therefrom into the open end of said filter bag, a source of cleaning gas, duct means connecting said `source to said nozzle to supply cleaning gas thereto, valving means in said duet to control the fiow of cleaning gas from the source to the nozzle, a source of fire extin- 3 guishing material, a conduit connecting the source of re extinguishing material to the dust means, valving means in the conduit controlling the How of said material to the nozzle therethrough and means responsive to temperature within the lter housing to simultaneously actuate the valving means in the duct for the cleaning gas and the Valving means controlling the supply of re eX- tinguishing material through the conduit to terminate the ow of cleaning air to the nozzles and permit the flow of fire extinguishing material thereto upon a predetermined increase in temperature.

2.y Apparatus for ltering solids from a uid carrier as dened in claim 1 wherein the means responsive to temperatures of the filter compartment comprises a meltable fuse in the passageway intermediate the source of ire extinguishing material and the nozzle.

3. Apparatus for ltering solids from a uid carrier as defined in claim 1 wherein the cleaning fluid and the re extinguishing material are both contained at their sources under pressure whereby opening their respective valving means permits them to exhaust from the nozzle into the filter bag.

4. Apparatus for filtering solids from a uid carrier as defined in claim 1 wherein the source of cleaning :duid and the source of re extinguishing material lie at opposite ends of a common passageway.

References Cited UNITED STATES PATENTS 7/1952 Rand et al. 169-19 4/ 1953 Farr 55-242 OTHER REFERENCES Pulverizing Machinery Bulletin PC-l, pp. 1-12, Apr- 25, 1966 (a copy in 55341).

FRANK W. LUTTER, Primary Examiner B. NOZICK, Assistant Examiner UJS. C1. X.R.

Images