Abstract:
Disclosed is a gas pressure regulator for gas or liquid that has inlet, an outlet and a diaphragm positioned between said inlet and said outlet in an manner that one side of the diaphragm controls the flow of fluid through the inlet to the outlet, a vent exposed to the opposite side of said diaphragm, and a spring in association with the opposite side of the diaphragm to adjust the position of the diaphragm, and a gas porous filter positioned in an manner that is adjacent the vent.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention concerns a vent cover for a gas pressure regulator. Some environments that require a gas pressure regulator are extremely dirty. When the vent on the gas pressure regulator becomes clogged from dust or from wash down, for example, the gas pressure regulator can become slow in reaction time and/or may operate incorrectly. The solution is to provide a gas porous filter having certain characteristics that keep the dust and washing solutions from blocking the vent. The filter can be produced from any porous material such as foam, interlocking metallic shaving, steel wool, or porous cloth. 
       BACKGROUND 
       [0002]    The invention concerns a vent cover for a gas pressure regulator. Some environments that require a gas pressure regulator are extremely dirty. A typical example is in an animal confinement building housing chicken, pig, cow, or other livestock, where, due to the noxious gases and dusty environment, significant ventilation is required to provide adequate breathing air. The ventilation fans cause the lightweight dust from the litter on the floor of the confinement building to become substantially airborne. A typical confinement building for chickens may have more than 4 inches deep of litter on the entire floor of the building where the materials can be very fine particles from wood shavings or rice husks or other absorbent materials. During the period between occupancy in the confinement building it may be necessary to wash down the inside of the building and the equipment in the building to sanitize the environment. Also during the period where the building is not occupied the ventilation fans are not in use and it is common that the atmosphere can become very humid and this leads to condensation on surfaces inside the building. Typical confinement building temperatures when the occupancy period begins have to be maintained such that the animals are in comfortable conditions to promote healthy growth in the case of chickens this temperature is 90 degrees Fahrenheit. Under these harsh conditions it is common that the combination of fine dust, moisture followed by elevated temperatures will form dense concentrations of fine dust. Typically gas pressure regulators are equipped with a very small vent hole which can measure as little as a few thousands of an inch. If the vent hole of the gas pressure regulator becomes clogged with this dense matter it is practically impossible to clean the vent hole and therefore the gas regulator will not operate as intended. 
         [0003]    Gas pressure regulators are well known and are particularly useful for controlling the flow of fluids, such as liquid petroleum gas (propane) or natural gas (methane), as they flow into a burner for heating purposes. Gas pressure regulators, such as used to regulate and reduce the gas pressure of natural gas or liquid petroleum gas, received from a relatively high pressure supply must be vented. The venting occurs on the side of the pressure regulating diaphragm not exposed to the gas, and the venting is necessary to allow the diaphragm to move freely without causing a vacuum or pressure condition within the vented cavity as well as allowing an escape for gas that would be released from the relief valve in case an over pressure condition was obtained at the outlet of the regulator. These may be found in gas (methane or propane, for example) or oil furnaces for residential, commercial buildings or process heaters. In the past, such gas pressure regulators were mounted in such a way that accumulation of dust or corrosive substances did not affect the operation of the regulators. Specifically they were positioned in housings, or otherwise mounted in such a way that falling dust would not accumulate on the gas pressure regulator, such as positioning the regulator under a solid surface. Also it is important that periodic wash down not affect the operation of the gas regulator. On the other hand it is important that the regulator be exposed to the variance in air pressure to assure that no matter what the air pressure is, the gas pressure regulator can supply the burner with a constant and steady supply of gas or oil, for example. When a very tight housing surrounds the gas regulator, the regulator cannot be adequately ventilated to the atmosphere and thus will not work satisfactorily. This is not a solution for many very dirty environments. 
         [0004]    U.S. Pat. No. 3,985,157 to Ferguson discloses an adjustable regulator vent cover that is exposed to adverse weather conditions such as icing. The vent cover for regulators having an internally threaded vented neck, in combination, a hollow body having inner and outer walls interconnected by a side wall, a first neck-receiving opening defined in said inner wall, a second neck-engaging opening defined in said outer wall coaxial with said first opening of a diameter slightly less than the diameter of the associated regulator neck, a vent opening defined in said side wall, and a cap having a threaded stem receivable within said second opening and a lip concentric to said stem of a diameter greater than the diameter of said second opening adapted to engage said outer wall adjacent said second opening. A gas pervious screen is mounted in the side wall to prevent insects from entering the interior of the gas regulator. 
       SUMMARY OF THE INVENTION 
       [0005]    The solution to the present invention is to provide a gas porous filter having certain characteristics that keep the fine dust from blocking the vent. The filter can be produced from foam, interlocking metallic shaving, steel wool, porous cloth, a fibrous non-woven product made from natural or synthetic fibers, or any other porous material. The filter can be removed for cleaning or replacement with a new filter in the event that it becomes clogged with dust that has been deposited on the filter through the process of ventilating the confinement building. 
         [0006]    In the broadest sense the invention is the combination of a gas pressure regulator having an inlet, an outlet and a diaphragm positioned between said inlet and said outlet in an manner that one side of the diaphragm controls the flow of fluid from the inlet to the outlet, a vent exposed to the opposite side of said diaphragm, and a spring in association with the opposite side of the diaphragm to adjust the position of the diaphragm, and a gas porous filter positioned in an manner that is adjacent the vent. 
     
    
     DESCRIPTION OF THE INVENTION 
       [0007]    With regard to  FIG. 1 , a gas pressure regulator  10  possesses a body sufficient to withstand the forces normally found in a gas regulator, preferably of metal or plastic or a combination of both. The gas pressure regulator  10  comprises a first body portion  12 , a second body portion  14  attached to said first body portion  12 , and a third body portion  16  attached to said second body portion. Preferably the first, second and third body portions are secured to one another by means of screws, rivets, etc. not shown. The first body portion  12  has an inlet opening  18  and an outlet opening  20 . The first body portion  12  also contains a narrow neck portion  22  between the inlet  18  and the outlet  20 , having an elastomeric or rubber seat  26  that further reduces the cross-sectional opening  24  of the narrow neck portion  22 . The first body portion  12  also contains a groove  28  at the top of the regulator as it is positioned in  FIG. 1 , although the gas regulator can be positioned in any direction, including upside down from the position shown in  FIG. 1 . Positioned in groove  28  is a diaphragm  30  typically made from rubber or a thermoplastic elastomer such that it easily flexes due to a change in pressure as little as 0.10 inches water column to 25 psi and above. Secured to the diaphragm  30  is a valve stem  32  generally positioned in the middle of the diaphragm  30 . The valve stem  32  is sized to project into the narrow neck portion  22  and centrally arranged within the seat  26 . The valve stem  32  has a spherical surface  34  at one end thereof, that when conditions are such, the spherical surface forms a seal with the seat  26  to prevent gas or liquid from flowing to the outlet  20 . Contrarily, when conditions are such, the valve stem  32  will be positioned well away from the seat  26  to allow gas or liquid to easily flow from the inlet  18  to the outlet  20 . Lastly the valve stem  32  may be at any position in between these extremes and therefore it produces a variable flow between the inlet and the outlet in response to any varying pressure in the pressure from the inlet supply. 
         [0008]    To seal the diaphragm from dirt etc, the second body portion  14  is secured to the first body portion  12  such that it is in contact with the diaphragm  30  on the side  30 A opposite the side  30 B facing the narrow neck  22 . The second body portion  14  also is shaped to be in contact with the first body portion  12  as shown in  FIG. 1 . 
         [0009]    The third body portion  16 , as shown in  FIG. 1  is a separate part of the gas pressure regulator. However, it can be formed as a single monolithic structure with the second body portion  14 . The third body portion  16  has a central vent opening  36  that extends from the atmosphere to the side  30 A of diaphragm  30 . Positioned with the central vent opening  36  is an adjustment screw  38  and a spring  40  in contact with the adjustment screw  38  on one end and side  30 A of the diaphragm  30  on the other end. This allows the gas pressure regulator to be adjusted to permit a change in pressure as little as 0.10 inches water column and greater, such as up to 25 psi and above, depending on the pressure of the gas or liquid in inlet  18 . The adjustment screw  38  can be advanced toward or away from the diaphragm  30  as is desired, thus place more force on the spring  40  or removing force from the spring, respectively. Lastly a vent cap  42  may be positioned over the third body portion  16  to permit the vent opening  36  to be directed toward one side or the other, as desired. 
         [0010]    To keep the vent opening  36  from clogging up with dirt and debris, such as that in an animal confinement building, a gas porous filter  44  is positioned in contact with the vent opening. The filter can be made from foam rubber, foam elastomeric material, steel wool, elastomeric porous material, a fibrous non-woven product made from natural or synthetic fibers, woven or knitted fabric, interlocking metal shavings, and generally any porous material that is capable of screening out dirt and debris and allowing the vent opening to breath. 
         [0011]    In operation, the gas pressure regulator  10  may be adjusted at the factory to give the outlet pressure to an orifice (sometimes referred to as the set point) as required by the customer, or may be adjustable and set by the customer. The outlet pressure in opening  20  and the narrow neck opening  22  are selected by the customer to give the desired flow rate of liquid petroleum gas (propane) or natural gas (methane)necessary for the application. For example the inlet pressure in inlet  18  may be 7 inches water column for natural gas or 14 inches for liquid petroleum gas. When the inlet pressure increase in inlet  18 , the outlet pressure in  20  starts to increase, but the increasing force created on the diaphragm  30  causes the stem  32  to move toward and closer to seat  26 , thereby throttling the flow through the narrow neck  22  and reducing the pressure on the diaphragm  30 . As this pressure decreases in inlet  18 , the stem  32  moves away from the seat  26  allowing more flow and higher outlet pressure at  20 . The outlet pressure at  20  modulates with respect to the set point. 
         [0012]    Thus it is apparent that there has been provided, in accordance with the invention, a novel gas pressure regulator that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.