Stored Product Pests
Stored product pests have long been a problem in food processing plants, warehouses and storage structures (bins/silos). Stored product insect infestations deteriorate commodities both qualitatively and quantitatively by decreasing the nutritional value or causing mold, leading to a reduction in overall food quality.
Managing Insects in Industrial Structures Worldwide for Over 15 Years
Heat treatment using elevated temperatures (122-140°F) has been used for over a century and is making a comeback as a non-chemical, non-corrosive, non-toxic and effective alternative to chemical fumigants.
Broadly, Stored Product Insects include:
- Red Flour Beetles (Tribolium castaneum), Confused Flour Beetles (Tribolium confusum), Warehouse Beetles (Trogoderma variabile), Sawtoothed Grain Beetles (Oryzaephilus surinamensis), Cigarette Beetles (Lasioderma serricorne), Drugstore Beetles (Stegobium paniceum), Lesser Grain Borer (Rhyzopertha dominica)
- Rice Weevils (Sitophilus oryzae), Wheat Weevils (Sitophilus granarius)
- Indian Mealmoths (Plodia interpunctella), Angoumois Grain Moths (Sitotroga cerealella)
Insect infestations are managed with fumigants (Phosphine, methyl bromide, and sulfuryl fluoride), insecticide foggings/aerosols and residual insecticides. Chemical fumigants pose environmental concerns and are hazardous due to toxicity. For example, methyl bromide has been phased out since 2005 as it depletes stratospheric ozone layer (Montreal Protocol). Phosphine has been known to have corrosive effect on electrical circuitry and some insects have developed tolerance/resistance to it. Sulfuryl fluoride has concerns regarding the fluoride residues. Foggings/aerosols kill by surface contact and may not be effective as they have low penetration capability.
Unique Advantages & Benefits
TEMP-AIR, Inc.’s “positive pressurization” process offers unique advantages and benefits over chemical fumigations and other techniques of heat treatments. These are:
- No sealing is required as the space to be heated is under positive pressure
- Allows inspections during the heat treatment that helps identify areas of insect emergence and take corrective action such as cracks and crevices treatment
- Areas adjacent to structure under heat treatment such as shipping, offices etc. remain operational
- Low downtime and no associated cost of insurance and need to contact local authorities
- No phase-out
A Variety of Applications
Our professional Thermal Remediation® staff has over 15 years of experience performing industrial heat treatments in food processing plants, flour mills, warehouses and storage structures (bins/silos) in North America, Europe and Asia. Heat Treatment Applications Include:
- Food Processing Plants
- Pasta, Cereal, Bakeries, Baby Food, Pet Food
- Milling Industry
- Flour Mills, Rice Mills, Wheat Mills, Rye Mills
- Storage Structures
- Bins & Silos – concrete and steel
- Food, Beverage
- Organic Processing Plants and Storage
The Thermal Remediation® patented process uses 100% outside/fresh air to create positive pressure within the structure being heat-treated while managing the hot air flow using a configuration of high temperature fabric ductwork, fans and a real-time wireless temperature monitoring system. Our process involves raising the internal temperature of the structure between 122-140°F (50-60°C) using direct-fired make-up air heaters that use propane or natural gas as source of fuel.
Dr. Raj Hulasare will visit the facility that will potentially be treated. A nominal site-visit fee may be charged. This fee is fully credited to client’s account if the client chooses to move forward with the heat treatment or our services. The site visit includes presentation of heat treatment, joint walk-through in facility for assessment and feasibility of heat treatment ending with joint discussion on overall heat treatment perspective of the site. Prior to the site visit, the client will be requested to furnish information about the facility for engineering design and relevant information such as sprinkler head rating, temperature sensitive equipment etc. Generally, the presentation is attended by Supervisors from Quality/Sanitation Control, Production & Maintenance as they will be involved in heat treatment. A comprehensive checklist of things-to-do before, during and after heat treatment will also be discussed with the client.
The site visit is followed by a quote emailed to the client with a detailed site-specific engineering design and an estimate of heat treatment services.
On acceptance of the quote by the client, the scheduling of a heat treatment, including the logistics of equipment and technician requirement, is planned in consultation with the client. On arrival at the site, a pre-heat treatment inspection is performed by the Project Manager for readiness of facility for heat treatment in terms of proper cleaning for maximum heat efficacy and relevant safety issues. This is followed by Thermal Remediation® technicians setting up the equipment comprising of heaters, fans, high temperature ductwork and wireless temperature monitoring sensors in the space to be heated.
Based on real-time temperature data, the repositioning of fans and ductwork is done for effective and uniform heat distribution to avoid or eliminate potential hot and cold spots. A minimum lethal temperature of 122°F/50°C is necessary to kill all life stages of insects in machines, cracks and crevices (thermal mass). Temperature monitoring and airflow management are critical to obtain a uniform lethal temperature profile in the heated space. Depending on the characteristics of the structure, it may take anywhere from 3 to 10 hours to attain the minimum lethal temperature (122°F/50°C) in the heated space. The facility is then held at this lethal temperature for 24 hours so that heat penetrates the thermal mass of the structure to effectively kill all of the stored product insects. Routine in-site inspections to visually see insect activity are carried out during the heat treatment by following the buddy-system (minimum two persons).
At the end of the heat treatment, the burners on the heater are shut-down but the blowers are kept running to force ambient air into the facility for cool-down. The post-treatment teardown and shutdown lasts approximately 6-8 hours. A joint walk-through after the heat treatment is undertaken to see the effectiveness of heat and to note shortcomings, if any. Based on the temperature data and frequent inspections during heat treatment, a final report is prepared for the client. The report highlights pros and cons of the heat treatment process and any improvisations for the subsequent heat treatment. Other multiple tactics of pest management as part of IPM (Integrated Pest Management) are also discussed with specific reference to heat treatment.
The three major heat treatment components are:
- Temperature Monitoring System
The most common type of heaters used in Thermal Remediation® industrial heat treatments are THP-series direct-fired make-up air heaters. THP-series heaters feature electronic modulating burner controls that automatically adjust gas flow taking into account the set discharge and ambient temperature. These direct-fired heaters are equipped with a high velocity centrifugal blower providing large volumes of air and high static pressure allowing the equipment to work well with high temperature ductwork.
ETHP-series electric heaters may also be used for smaller spaces or storage structures (bins/silos) to manage stored product insects. This series has digital temperature controls providing precise temperature control. Its proof-of-air-flow control senses obstructed air intake and prevents coil from energizing. These electric heaters contain a built-in circuit breaker.
Our company uses custom designed, high temperature fans that provide a high CFM with low amperage draw. These fans are necessary to evenly distribute heated air throughout the space and target high infestation zones. The selection of fans depends on the layout of the space being heat treated and size selection ranges from 16 to 48 inches in diameter. The airflow management plays a crucial role in the success of a heat treatment.
Temperature Monitoring Systems
The expandable, wireless temperature monitoring system includes a laptop installed with proprietary temperature recording software, receiver, repeater and wireless temperature transmitters/sensors. The real-time temperature monitoring helps identify hot and cold spots in the treated area as well as regulates and controls hot air distribution. Comprehensive graphical temperature charts for the entire duration of a heat treatment are provided to the client along with the final report of the heat treatment.
To highlight the most common types of industrial stored product pest heat treatments scenarios we encounter, we have provided case studies showing brief overviews on past treatments.
Direct-fired propane heaters were used to kill stored product insects in a dry roast room and a storage room.Read Full Case Study
Make-up air gas heaters were used to eliminate stored product pests in a tempering room.Read Full Case Study
This study compares the results of heat treatment vs. chemical fumigation.Read Full Case Study