1、 ANSI/ASABE S613-2.1 JUN2013 Tractors and self-propelled machinery for agricultureAir quality systems for cabsPart 2: Cab principally agricultural field equipment, farmstead equipment, structures, soil and water resource management, turf and landscape equipment, forest engineering, food and process
2、engineering, electric power applications, plant and animal environment, and waste management. NOTE: ASABE Standards, Engineering Practices, and Data are informational and advisory only. Their use by anyone engaged in industry or trade is entirely voluntary. The ASABE assumes no responsibility for re
3、sults attributable to the application of ASABE Standards, Engineering Practices, and Data. Conformity does not ensure compliance with applicable ordinances, laws and regulations. Prospective users are responsible for protecting themselves against liability for infringement of patents. ASABE Standard
4、s, Engineering Practices, and Data initially approved prior to the society name change in July of 2005 are designated as “ASAE“, regardless of the revision approval date. Newly developed Standards, Engineering Practices and Data approved after July of 2005 are designated as “ASABE“. Standards design
5、ated as “ANSI“ are American National Standards as are all ISO adoptions published by ASABE. Adoption as an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by ASABE. Consensus is established when,
6、 in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, a
7、nd that a concerted effort be made toward their resolution. CAUTION NOTICE: ASABE and ANSI standards may be revised or withdrawn at any time. Additionally, procedures of ASABE require that action be taken periodically to reaffirm, revise, or withdraw each standard. Copyright American Society of Agri
8、cultural and Biological Engineers. All rights reserved. ASABE, 2950 Niles Road, St. Joseph, Ml 49085-9659, USA, phone 269-429-0300, fax 269-429-3852, hqasabe.org ANSI/ASABE S613-2.1 JUN2013 Copyright American Society of Agricultural and Biological Engineers 1 ANSI/ASABE S613-2.1 JUN2013 Revision app
9、roved June 2013 as an American National Standard Tractors and self-propelled machinery for agriculture Air quality systems for cabs Part 2: Cab approved by the Power and Machinery Division October 2010; approved as an American National Standard November 2010; revised June 2013; approved by ANSI June
10、 2013. Keywords: Air quality, Cabs, Environment, Engineering control, Filters, HVAC, Procedures, Safety, Terminology, Test, Tractor, Ventilation 1 Scope 1.1 This part of the S613 standard series is concerned with the generally accepted design principles that define a robust cab and HVAC system used
11、in contaminated environments as part of an Occupational Health and Safety Management System (OHSMS). This document is intended to be a guide for engineers who are responsible for designs used in agricultural applications. Information provided by this part of the standard series should help engineers
12、 provide cab and HVAC system designs that can be used as an engineering control within a program of risk management. 1.2 While this standard provides broad guidance for design of these systems, it is only concerned with current state of the art designs and technologies. It is expected that as new te
13、chnologies are developed and new insight into the function of these systems are gained, these guidelines may become obsolete and this standard may need to be re-written, revised or replaced. 1.3 This standard should not limit design advancement. 1.4 System performance guidelines will be the primary
14、consideration of this part of this standard series. 1.5 Filter design will be addressed by another part of this standard series. 1.6 This standard will only propose those techniques and technologies that are non-proprietary and in the public domain. 1.7 Cabs for use in poison gas or oxygen depleted
15、environments are not covered by this standard. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies unless noted. For undated references, the latest approved edition of the referenced do
16、cument (including any amendments) applies. ASABE/ISO 14269-2 Tractors and self-propelled machines for agriculture and forestry Operator enclosure environment Part 2: Heating, ventilation and air conditioning test method and performance ASABE/ISO 14269-5 Tractors and self-propelled machines for agric
17、ulture and forestry Operator enclosure environment Part 5: Pressurization system test method ANSI/ASABE S613-2.1 JUN2013 Copyright American Society of Agricultural and Biological Engineers 2 3 Type of Airborne Contaminants The cab filtration system design should consider the particular types of airb
18、orne contaminates that the tractor or self-propelled machinery will be typically operating in such as soil preparation, pesticide spraying, harvesting, etc. 3.1 aerosols: These are fine sized solids or liquids that remain airborne for extended periods of time. 3.1.1 solid particles: Particle contami
19、nants can be comprised of mineral dusts (silica, clay, etc.), biological dusts (grain, pollen, etc.), and/or combustion products (smoke, diesel soot, etc.). Dusts tend to be larger than 1 m, while smoke, fumes and engine products tend to be less than 1 m in size 1-3. 3.1.2 liquid: Liquid contaminant
20、s can be comprised of pesticide spray droplets, oil mists and chemical mists. A majority of pesticide spray droplets tend to be larger than the respirable size of 10 m with some droplets less than 3 m present from liquid evaporation 4. Mists tend to contain droplets less than the respirable size of
21、10 m 1,2. 3.1.3 gases: Gases are molecular matter dispersed in air in an unrestricted physical state. Airborne gas contaminates can be a product of chemical reactions or a vapor phase of liquids or solids. 4 Sources of Airborne Contaminants Considerations should be given to the cab as an engineering
22、 control for the operating environment of particular tractors or self-propelled machinery. The cab filtration system design should consider several filtration alternatives for the various operational solid, liquid, and/or gas contaminants. 5 Cab as a Physical Barrier The cab enclosure provides a phy
23、sical barrier around the operator and a controlled environment inside the cab. The HVAC system should be designed with enough heating, ventilation, and air conditioning capacity to maintain comfortable temperature and air quality for the vehicle operator(s). 5.1 Description. The cab enclosure is the
24、 physical nonporous boundary surrounding the operator compartment from the outside environment that the tractor or vehicle operates in. The HVAC system includes all the ductwork, fans, heat exchangers, and interactive control systems to manage temperature and airflow parameters inside the cab enclos
25、ure to provide the operator with a comfortable environment. Air purifying devices are integrated into the HVAC system to remove contaminants from the air and control the air quality inside the cab enclosure. The cab system and its components become an engineering control in a managed occupational sa
26、fety and health program. 5.1.1 Objective. The objective of an enclosed cab is to provide a managed environment for the vehicle operator. 5.1.2 Components and Operation. Enclosed operator cabs have numerous structural, ergonomic, HVAC, and air cleaning design elements that have to be complementary to
27、 a vehicles operator compartment. 5.1.2.1 Enclosure. The enclosure should be a physical nonporous barrier surrounding the operator compartment from the outside environment. This barrier should be integrated with the other operator vehicle compartment safety devises such as roll over protection struc
28、ture (ROPS) and falling object protection structure (FOPS). Elements of this enclosure should consist of structural materials, windows for outside vehicle observation and door(s) for enclosure access. The enclosure should provide some small openings for the intake airflow to be pushed outside the ca
29、b under positive pressure. These openings should be shielded or located away from potential outside air flow velocity infiltration into the cab such as wind or engine fan air currents. The relationship between airflow, orifice area, and static pressure are shown below for uncompressed gases or air.
30、This relationship can be used to estimate the quantity of airflow needed to pressurize a cab ANSI/ASABE S613-2.1 JUN2013 Copyright American Society of Agricultural and Biological Engineers 3 given a designed open area of the cab to the outside. The circular discharge orifice discharge coefficient of
31、 0.61 was used by some for cabs and is considered reasonable, given a small orifice area as compared to the pressurized area behind the opening 5-7. airdCAQ0002= Where: Qo= Airflow quantity exiting through cab orifice, Cd= Orifice discharge coefficient, 0.61 Ao= Area of orifice, po= Air pressure dif
32、ferential across cab orifice, air= Air density. 5.1.2.2 Cab Intake Air Inlet. The air intake inlet into the HVAC System should be located at a position on the cab that would be expected to have the lowest contaminant concentrations generated from the vehicles operation. This shall include the vehicl
33、es engine exhaust plume. 5.1.2.3 Fan. A multiple speed fan is the primary air moving component of a HVAC system (see figure 1). For maximum effectiveness this fan is usually positioned on the downstream side of the recirculation and intake air streams of the HVAC system to move the total amount of a
34、irflow through the system. An additional booster fan (pressurizer) may also be used in the intake fresh air stream of the HVAC system to assist with boosting intake airflow into the cab (see figure 1) and as a means for pressurizing the interior of the cab such that a positive pressure can be mainta
35、ined inside the cab, taking into account the velocity of the wind outside of the machine. If there is a limitation on the external wind velocity necessary to maintain pressurization it must be clearly defined in the cab specifications and the operators manual. The fan(s) should have adequate pressur
36、e-quantity capacity to overcome the resistance of the heat exchangers, HVAC ductwork, and air purifying devices, including dirty filters, while delivering at least 43 m3/hr, 25 ft3/min, of intake air into the cab per occupant from the lowest to the highest fan speed(s). Figure 1 Enclosed Cab Operati
37、ng Parameters (Cab Model Variables are in Bold) I pI C ALQLor l QI pR R QR Aovw QwWhere: I Intake Filter Efficiency pI Pressure Differential Across Intake Filter AL Intake Leakage Area QL Intake Air Leakage Quantity QI Intake Air Quantity l Fraction of Intake Air Leak, QL/QIR Recirculation Filter Ef
38、f. pR Pressure Across Recir Filter QR Recirculation Air Quantity vo Cab Exit Air Velocity Ao Exit Opening pc Pressure Differential Across Cab w Wind Velocity Qw Quantity of Wind Infiltration Vc Cab Volume x Inside Contaminant Concentration C Outside Contaminant ConcentrationMultiple Speed HVAC Fan S
39、ingle Speed Pressurizer FanQI+R xVcQIor vopcHeat Exchanger ANSI/ASABE S613-2.1 JUN2013 Copyright American Society of Agricultural and Biological Engineers 4 5.1.2.4 Filter. These are the individual components that remove contaminates from the airflow passing through the air purifying device(s) integ
40、rated into the HVAC system. 5.1.2.5 Ductwork. Enclosed cab HVAC ductwork should be sealed to minimize air leakage around the air purifying device(s). Ductwork joints in the negative pressure zone between the filter and the fan should be designed to minimize the likelihood of leakage under normal ope
41、rating conditions. 5.1.2.6 Air Tempering. Heating and air conditioning should be of sufficient capacity to heat and air condition the cab volume within a comfortable operating range while overcoming the thermal heating and cooling losses through the windows and cab structure. 5.1.2.7 Controls. The H
42、VAC system should provide the operator with temperature and airflow control over the interior cab environment. 5.1.3 Filter Loading Effects on System Performance. Each of the different types of filters, mechanical, electrostatic and absorbent media, affects system performance differently. These effe
43、cts should be considered in the system design and the application effects should be described in the operators manual. 5.1.4 Sources of Contamination. Contamination infiltration potentially comes from several routes of entry. 5.1.4.1 Filter Efficiency. Filter efficiency would be addressed in the cab
44、 design process from the consideration of the allowable application of the cab for hazardous environment application, i.e. what is the maximum filtration level that is useable in this cab? 5.1.4.2 Filter Bypass. This is the outside air that migrates around the filter media or air purifier into the c
45、ab enclosure. 5.1.4.2.1 Filter Seals. Air leakage around the filter seals in the air purifier device. The filter sealing material should be on the filter so that there is a new seal with each new filter. The sealing interface should be designed so as to minimize the likelihood of seal damage during
46、installation of the filter. The surface to which the filter seals should be designed in such a manner that it remains sealed throughout the life of the cab. 5.1.4.2.2 Filter Media Damage. A tear or openings in the filter media that provides an unfiltered air pathway through the filter. 5.1.4.2.3 Fil
47、ter Saturation wind infiltration for 25.0waircv Where: vo = Wind velocity infiltration into the cab orifice, Qw = Wind air flow quantity infiltration into the cab orifice, 0.61 = Orifice discharge coefficient (Cd), ANSI/ASABE S613-2.1 JUN2013 Copyright American Society of Agricultural and Biological
48、 Engineers 5 Ao= Area of orifice, air = Air Density, vw= Wind velocity, pc= Cab pressure. 5.1.4.5 Induction. Air drawn into a positively pressurized air stream through a leak or opening located at a constricted cross-sectional area of conduit or duct. This air induction into the positively pressuriz
49、ed airstream is caused by the offsetting decrease in static pressure associated with the increase in velocity pressure at the constricted area (venturi effect). 5.1.4.6 Operator Introduction. These are contaminants that are carried into the cab on the operator or left into the cab enclosure by the operator opening the door or windows. An air purifier located in the recirculation airflow circuit of the HVAC system can remove airborne contaminants from t
