Chilled ingredient water for dough mixing cooling; chilled fluid for jacket cooling of the mixer; ice for dough mixing- temperature control.
Bakery products, primarily breads, sweet rolls and buns are high production volume and temperature control during the dough mixing process is critical to the final quality. Principle sources of high temperatures are the heat of hydration (flour absorbing water) and heat of friction (mixer motor energy).
Recommended Ice Solutions
To offset the principle heat factors in the mixing process consisting of the heat of hydration (flour absorbing water) and heat of friction (mixer motor) chilled water and/or ice is added to the mixing process.
VOGT® has a complete line of icemakers, chillers, ice storage systems, and delivery systems to meet each individual customer’s needs.
- Complete line products – chillers, icemakers and accessory equipment. – Single source responsibility for the system. – Proven experience in solving customer problems with reliable solutions. – Chilled ingredient water can be delivered to the mixing process by one of two methods.
Chilled Water System
- Chilled ingredient water can be delivered to the mixing process by one of two methods.
- TURBO Chiller – HTD or HF chillers
- Thermal energy storage systems – HP or ATS/FTS for closed loop chilling systems.
Ingredient water typically ranging from 35 deg to 39 deg F can be supplied by HTD and HF type Turbo Falling Film chillers. The cleanable nature of the chiller and stainless steel construction make it the preferred way to supply clean ingredient water.
Ingredient water is cooled from temperatures as high as 85 to 90 deg F down to 35 to 39 deg F in a single pass. The ingredient water enters the chiller at the higher temperature and leaves at the lower temperatures and can be delivered directly to the mixing system or to a storage tank for later use. TURBO chillers can deliver water to within one (1) degree of the freezing point.
Chiller products can deliver several hundred gallons per minute of chilled water to the mixing process typically with a single chiller.
Fragmented ice can be added to the mixing process to provide the required cooling of the mixing process. Because of the fragmented ice shape and size the ice melts quickly to achieve the desired temperature but unlike flake ice it is able to maintain a uniform temperature by releasing the cooling over a longer period of time due to its shape and size of the fragments.
Thermal Energy Storage (HP and ATS/FTS) for water chilling
Thermal energy storage (TES) systems use ice generators mounted on top of storage tanks. Ice is produced during night time or other periods of low electric utility rates and stored in a concrete or lined steel tank. During the processing hours the 32 deg F water from the mixture of water and ice in the storage tank is circulated through a plate frame heat exchanged to obtain the 35 to 39 deg F required for the ingredient water. TES systems typically operate at higher evaporator temperatures and are more efficient than standard icemakers. With or without electric utility rebates or lower utility rates the TES provide a reliable method to store the required cooling for the mixing process.
Chiller and Icemaker Products
Chillers are available n three different plate sizes and eight different cabinet sizes to meet a wide range of customer requirements. All TURBO chillers are constructed stainless steel and include a number of reservoir sizes for collection of the chilled water used for delivery to the mixing process. Chillers are available in R-22, R-404a and ammonia (both flooded and liquid recirculated systems) Chillers are available as low sides only or as complete self-contained systems. Self-contained systems include the chiller and high side packaged on a common skid for easy installation into the bakery.
VOGT offers a number of icemakers suitable for bakery applications using both HFC Refrigerants and ammonia refrigerants. P series icemakers providing a round cylinder (tube) ice ranging in capacities from 5 to 125 tons of ice per day in HFC Refrigerants and ammonia. Modular C-Line series icemakers producing a fragmented ice on plate icemakers. The C-Line series uses a water defrost system to provide a dry sub-cooled ice. Capacities in 13 tons of ice per day per module with ammonia. Modular MHG series icemakers providing a fragmented ice on plate icemakers. The MHG series use a hot gas defrost and produce higher capacity than the C-Line series in the same foot print. Capacities in 26 tons per day per module with HFC Refrigerant or ammonia. Simple user friendly controls can be used to adjust the ice thickness to meet the customer’s needs. Ice can be produced continuously to meet the ice requirements as it is needed or during non-production period and stored for later use.
If the ice requirements are met using icemakers to produce the ice as it is required, a larger icemaker is typically required. The icemaker capacity depends on the hours of processing and the amount of ice required. This method eliminates the need to store ice – ice is delivered directly to the mixing process. Smaller icemakers can be used with the addition of ice storage and production of ice during non-production hours.
Ice Storage and Delivery Systems
Ice rake systems:
- TURBO ice rake systems are designed for storage of tube, or fragmented ice produced by the VOGT line of icemakers. Capacities up to 87 tons can be obtained.
- CB Rakes are available in three rake assembly sizes and 4 different capacities. Completely automatic loading and unloading of the ice through the use of a programmable logic controller to monitor all aspects of the rake system operation ensuring reliable operation. CB rakes range in capacities from 49 to 87 tons of ice.
- The CB Rake is completely automatic – unload and load operation require the operator to turn on the “Delivery” switch.
Thermal Energy Storage System
Thermal energy storage systems consist of:
- Ice generator
- Ice and water storage tank
- Pumping system
- Plate frame exchanger
The ice harvester is located on top of a storage tank. Ice is produced on vertical stainless steel evaporator plates and periodically harvested. This ensures the optimum heat transfer at all times unlike ice-on-coil systems. The ice that is produced is stored in the tank located under the icemaker. The 32ºF ice/water mixture in the tank is pumped to the process or a plate frame heat exchanger to provide the required process cooling requirements. The ice can be produced and stored for later use during non-production hours or periods of low electrical utility rates.
- TES ice generators are available in sizes from 40 to 850 tons in R-404a and ammonia
- Low side (evaporator only) or complete self-container systems up to 100 tons
- Ice generators can operate as icemaker or chiller.
- Programmable logic controller to control ice making and chiller mode
Ice/Water Storage Tanks
- TES systems require tanks to store the ice and water mixture used for cooling. Tanks are available in above ground and in-ground tanks.
- Above ground tanks can be constructed for steel or concrete and lined.
- Tank design guidelines for single and multiple ice generators are available.
- In-ground tanks can also be fabricated from steel but are typically insulated concrete.
- Storage tanks are required to store the 32 deg F ice and water until it is needed for the process.
Pumping system to circulate the water from the tank to the ice generator and/or plate frame heat exchanger can be provided.
Plate Frame Heat Exchanger
A clean in place heat exchanger is used to chill the ingredient water to 35 to 39 deg F using the 32 deg F water from the TES system.
Ice features and benefits
- Fragmented ice for reliable temperature control.
- Quick release of BTU’s to the mixing process.
- No lumping of ice product in the mix.
- Variable ice thickness control for desired ice type.
- Storage and delivery systems to integrate in to any plant process. – Use off peak energy with TES systems
Chilled water features and benefits
- Instantaneous chilling of ingredient water for mixing process.
- 33 ° F water temperature available for chilling.
- All stainless steel construction.
- Wide range of sizes and capacities.