Questions and Answers
What is the maximum noise level allowed for the heated-air mechanical grain dryer?
The warranty for the mechanical grain dryer includes all parts for two years after purchase.
False
What type of tools shall be provided with the heated-air mechanical grain dryer unit?
Basic tools
The dust emission from the mechanical grain dryer must be within acceptable limits set by the _______.
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What is the maximum allowable percentage increase of cracked grain for rice in a mechanical grain dryer?
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Match the following components with their warranty duration:
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What features are required for access during repair and maintenance of the mechanical grain dryer?
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The maximum spillage percentage allowed for corn in a mechanical grain dryer is 1.0%.
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What is the minimum drying efficiency required for a mechanical grain dryer?
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All metal parts of the grain dryer should have rough surfaces to ensure strength.
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The maximum moisture gradient allowed is ___%.
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What standard must the operation manual conform to?
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Which of the following fuels has the lowest minimum heating system efficiency in a mechanical grain dryer?
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Match the following performance criteria with their maximum allowable values for corn:
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All rotating parts in the mechanical grain dryer must be unbalanced.
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What distinguishes a batch type dryer from a continuous flow dryer?
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What is an essential feature that the dryer must be equipped with to measure air temperature?
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The counter-flow type dryer moves the drying air in the same direction as the grain being dried.
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Name a type of continuous flow dryer that includes mixing to occur during operation.
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A __________ type batch dryer is where the grain is held in a vertical grain holding bin.
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Match the following type of dryers with their descriptions:
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Which of the following is a characteristic of a flat bed type dryer?
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A recirculating type dryer does not mix the grain during the drying process.
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What is the drying process in a continuous flow dryer compared to a batch type dryer?
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Which type of dryer allows the products of combustion to come into direct contact with the product being dried?
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The moisture gradient refers to the average moisture content of the grain after drying.
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What is the purpose of a dust collecting system?
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A grain dryer is used to remove excess moisture from the grain, generally by forced or natural __________.
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Match the following types of heat introduction methods with their descriptions:
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What is defined as the ratio of total heat utilized to vaporize moisture to the amount of heat added to drying air?
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Head rice is defined as a fraction of grain shorter than eight-tenth (8/10) of the whole grain length.
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What is the role of a plenum in a grain dryer?
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A __________ dryer passes grain intermittently in cycles or stages through the drying chamber.
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Which of the following is not a classification of heated-air mechanical grain dryers?
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What is primarily excluded from the specifications of this standard?
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This standard applies to both palay and corn grains.
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Name one of the publications considered in the preparation of the standard.
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This standard is specifically for heated–air mechanical grain dryer used for ______ purposes.
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Match the following documents with their relevance:
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Which grain-related document relates to specifications for heated-air mechanical grain dryers?
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Study Notes
Preparation of the Standard
- Consideration of ISO/DIS 11520-1: Agricultural Grain Dryers for drying performance evaluation.
- Inclusion of parts from the Regional Network for Agricultural Machinery regarding continuous flow and batch rice dryers.
- Reference to Justin Tumambing's paper on the status of grain dryers in the Philippines.
- Philippine Agricultural Engineering Standard PAES 201:2000 outlines specifications for heated-air mechanical grain dryers.
Scope of the Standard
- Defines the requirements for heated-air mechanical grain dryers for commercial use, excluding seed dryers.
- Grain refers specifically to palay (unhusked rice) and corn.
Reference Document
- PAES 202:2000: Provides testing methods for heated-air mechanical grain dryers.
Definitions
-
Batch Type Dryers: Hold fixed volumes of grain until moisture content is achieved.
- Flat Bed: Grain held in shallow bins.
- Recirculating: Circulates grain during drying.
- Vertical Bin: Grain held in vertical bins.
-
Continuous Flow Dryers: Drying occurs as grain moves continuously through the chamber.
- Variation types include concurrent flow, counter-flow, cross-flow, mixing, and non-mixing.
-
Dryer Types:
- Direct-Fired: Combustion products directly contact grain.
- Indirect-Fired: Combustion products do not contact grain.
- Drying Efficiency: Measure of heat utilization for moisture vaporization.
Performance Criteria
- Standard sets performance benchmarks for rice and corn dryers, including:
- Final moisture content: 14% (wet basis).
- Maximum moisture gradient: 2.0%.
- Product quality limits on cracked grain (5% increase for rice, 35% for corn), head rice, hulled/damaged grain, and split kernels.
- Spillage: Maximum 0.5%.
- Minimum drying efficiency: 75%.
Heating System Efficiency
- Defines minimum efficiencies based on fuel type:
- Petroleum based fuels: 90% (direct), 75% (indirect).
- Biomass fuels: 65% (direct), 50% (indirect).
Safety and Maintenance Features
- Must include fire control provisions and protection for moving parts.
- Noise level must not exceed 92 dB(A).
- Dust emission regulations must comply with environmental standards.
- Complete operations manual and basic tools must accompany each unit.
- After-sales service, spare parts, and identification of wearing parts are essential.
Warranty and Durability
- Construction of grain dryers should be robust to prevent major breakdowns within one year.
- Warranty applies to parts and services, lasting one year post-acceptance, excluding fast-wearing components.
Workmanship and Finish
- Mechanical grain dryers must be free from defects that could impact safety or usability.
- Standardized uniformity across components of the same brand and model is required.
Sampling for Testing
- All dryer units must be sampled according to PAES 103:2000 for agricultural machinery methodologies.
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Description
Test your knowledge on the standards and performance determinations concerning agricultural grain dryers. This quiz covers key documents and studies relevant to rice dryer technology, particularly in the context of the Philippines. Perfect for students and professionals in agricultural engineering.
