Heat recovery

In laundry, energy costs for heating water are essential. The recovery of the amount of heat contained in the wastewater is a particularly effective measure for saving energy.

There are waste water heat exchangers and increasingly also exhaust air heat exchangers for recovering the waste heat from mangles and finishing devices. In these areas we cooperate with UHS, a highly specialized company for such issues.

Waste water heat exchangers are typically used. The principle of heat recovery is as simple as it is effective: In the heat exchanger, the amount of heat in the wastewater is transferred to the fresh water or the washing liquor; the waste water cools down while the fresh water is heated.

There are different heat exchanger systems on the market. Generally, they comprise pipes or plate heat exchangers in which the waste heat of the waste water is transferred to fresh water in the counterflow. The capacity of the heat exchanger must be adapted to the volume flows in the operation. The longer the heat exchanger is and the more surface it has, the better is its efficiency. A modern heat exchanger can recover up to 50% of the energy used in the washing process.
The use of heat exchangers is of particular advantage for hospital laundry, flat laundry with minor to medium soiling and for laundry from the hotel and catering industry.

UniSystem MI-4000 – Heat exchanger for washing extractors

The waste water heat exchanger MI-4000 is an easy-to-install system that can be mounted to the end of the drainage pipeline of washer extractors. The system is particularly suited for smaller laundries with a fresh water consumption of up to 500 l/min.

The heat exchanger works similar to an instantaneous water heater in a household. The system switches on automatically as soon as fresh water is withdrawn. The heat accumulator is the water tank which is fed by the washer extractors. The self-priming waste water pump pumps the warm waste water in the counterflow through seven internal twisted pipes while the fresh water in the outer tube flowing in the opposite direction is heated. The heated fresh water is fed into the washing machine so that energy is saved. When flowing through the heat exchanger, the laminar flow of the waste water changes to turbulent flow which prevents deposits in the device and increases the heat transfer coefficient by up to 60% as compared to other systems. The MI-4000 is easy to install and requires only a small space of 3.5 x 0.5 x 1 m (W x D x H).

Models of the UniTwist DT series are heat exchangers in modular design for washing tunnels and offer variable installation options: under the washing tunnel, at the ceiling or on the wall. The DT series consists of individual modules that are available with different diameters and with a length of 1 m or 6 m. This allows the heat recovery system to be adapted individually to the operating conditions – as a single-unit solution for a washing tunnel or as a heat recovery system for the entire waste water of a laundry.